Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* i2c-core.c - a device driver for the iic-bus interface */ |
2 | /* ------------------------------------------------------------------------- */ | |
3 | /* Copyright (C) 1995-99 Simon G. Vogl | |
4 | ||
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
7 | the Free Software Foundation; either version 2 of the License, or | |
8 | (at your option) any later version. | |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
ca1f8da9 | 13 | GNU General Public License for more details. */ |
1da177e4 LT |
14 | /* ------------------------------------------------------------------------- */ |
15 | ||
96de0e25 | 16 | /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>. |
1da177e4 | 17 | All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl> |
421ef47b | 18 | SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and |
7c81c60f | 19 | Jean Delvare <jdelvare@suse.de> |
0826374b | 20 | Mux support by Rodolfo Giometti <giometti@enneenne.com> and |
687b81d0 WS |
21 | Michael Lawnick <michael.lawnick.ext@nsn.com> |
22 | OF support is copyright (c) 2008 Jochen Friedrich <jochen@scram.de> | |
23 | (based on a previous patch from Jon Smirl <jonsmirl@gmail.com>) and | |
24 | (c) 2013 Wolfram Sang <wsa@the-dreams.de> | |
17f4a5c4 WS |
25 | I2C ACPI code Copyright (C) 2014 Intel Corp |
26 | Author: Lan Tianyu <tianyu.lan@intel.com> | |
4b1acc43 | 27 | I2C slave support (c) 2014 by Wolfram Sang <wsa@sang-engineering.com> |
687b81d0 | 28 | */ |
1da177e4 | 29 | |
44239a5a WS |
30 | #define pr_fmt(fmt) "i2c-core: " fmt |
31 | ||
b4e2f6ac | 32 | #include <dt-bindings/i2c/i2c.h> |
53feedf8 WS |
33 | #include <asm/uaccess.h> |
34 | #include <linux/acpi.h> | |
35 | #include <linux/clk/clk-conf.h> | |
36 | #include <linux/completion.h> | |
5f9296ba | 37 | #include <linux/delay.h> |
53feedf8 | 38 | #include <linux/err.h> |
1da177e4 | 39 | #include <linux/errno.h> |
5f9296ba | 40 | #include <linux/gpio.h> |
53feedf8 | 41 | #include <linux/hardirq.h> |
1da177e4 | 42 | #include <linux/i2c.h> |
1da177e4 | 43 | #include <linux/idr.h> |
53feedf8 WS |
44 | #include <linux/init.h> |
45 | #include <linux/irqflags.h> | |
46 | #include <linux/jump_label.h> | |
47 | #include <linux/kernel.h> | |
48 | #include <linux/module.h> | |
b3585e4f | 49 | #include <linux/mutex.h> |
959e85f7 | 50 | #include <linux/of_device.h> |
53feedf8 | 51 | #include <linux/of.h> |
687b81d0 | 52 | #include <linux/of_irq.h> |
f48c767c | 53 | #include <linux/pm_domain.h> |
53feedf8 | 54 | #include <linux/pm_runtime.h> |
3fffd128 | 55 | #include <linux/pm_wakeirq.h> |
e1dba01c | 56 | #include <linux/property.h> |
53feedf8 WS |
57 | #include <linux/rwsem.h> |
58 | #include <linux/slab.h> | |
1da177e4 | 59 | |
9c1600ed DB |
60 | #include "i2c-core.h" |
61 | ||
d9a83d62 DH |
62 | #define CREATE_TRACE_POINTS |
63 | #include <trace/events/i2c.h> | |
1da177e4 | 64 | |
da899f55 WS |
65 | #define I2C_ADDR_OFFSET_TEN_BIT 0xa000 |
66 | #define I2C_ADDR_OFFSET_SLAVE 0x1000 | |
67 | ||
6629dcff | 68 | /* core_lock protects i2c_adapter_idr, and guarantees |
35fc37f8 | 69 | that device detection, deletion of detected devices, and attach_adapter |
19baba4c | 70 | calls are serialized */ |
caada32a | 71 | static DEFINE_MUTEX(core_lock); |
1da177e4 LT |
72 | static DEFINE_IDR(i2c_adapter_idr); |
73 | ||
4f8cf824 | 74 | static struct device_type i2c_client_type; |
4735c98f | 75 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
f37dd80a | 76 | |
d9a83d62 | 77 | static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE; |
95026658 | 78 | static bool is_registered; |
d9a83d62 DH |
79 | |
80 | void i2c_transfer_trace_reg(void) | |
81 | { | |
82 | static_key_slow_inc(&i2c_trace_msg); | |
83 | } | |
84 | ||
85 | void i2c_transfer_trace_unreg(void) | |
86 | { | |
87 | static_key_slow_dec(&i2c_trace_msg); | |
88 | } | |
89 | ||
17f4a5c4 WS |
90 | #if defined(CONFIG_ACPI) |
91 | struct acpi_i2c_handler_data { | |
92 | struct acpi_connection_info info; | |
93 | struct i2c_adapter *adapter; | |
94 | }; | |
95 | ||
96 | struct gsb_buffer { | |
97 | u8 status; | |
98 | u8 len; | |
99 | union { | |
100 | u16 wdata; | |
101 | u8 bdata; | |
102 | u8 data[0]; | |
103 | }; | |
104 | } __packed; | |
105 | ||
166c2ba3 MW |
106 | struct acpi_i2c_lookup { |
107 | struct i2c_board_info *info; | |
108 | acpi_handle adapter_handle; | |
109 | acpi_handle device_handle; | |
110 | }; | |
17f4a5c4 | 111 | |
525e6fab | 112 | static int acpi_i2c_fill_info(struct acpi_resource *ares, void *data) |
166c2ba3 MW |
113 | { |
114 | struct acpi_i2c_lookup *lookup = data; | |
115 | struct i2c_board_info *info = lookup->info; | |
116 | struct acpi_resource_i2c_serialbus *sb; | |
166c2ba3 | 117 | acpi_status status; |
17f4a5c4 | 118 | |
166c2ba3 MW |
119 | if (info->addr || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) |
120 | return 1; | |
121 | ||
122 | sb = &ares->data.i2c_serial_bus; | |
123 | if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) | |
124 | return 1; | |
125 | ||
166c2ba3 MW |
126 | status = acpi_get_handle(lookup->device_handle, |
127 | sb->resource_source.string_ptr, | |
525e6fab OP |
128 | &lookup->adapter_handle); |
129 | if (!ACPI_SUCCESS(status)) | |
130 | return 1; | |
131 | ||
132 | info->addr = sb->slave_address; | |
133 | if (sb->access_mode == ACPI_I2C_10BIT_MODE) | |
134 | info->flags |= I2C_CLIENT_TEN; | |
17f4a5c4 | 135 | |
17f4a5c4 WS |
136 | return 1; |
137 | } | |
138 | ||
525e6fab OP |
139 | static int acpi_i2c_get_info(struct acpi_device *adev, |
140 | struct i2c_board_info *info, | |
141 | acpi_handle *adapter_handle) | |
17f4a5c4 | 142 | { |
17f4a5c4 | 143 | struct list_head resource_list; |
166c2ba3 | 144 | struct resource_entry *entry; |
525e6fab | 145 | struct acpi_i2c_lookup lookup; |
17f4a5c4 WS |
146 | int ret; |
147 | ||
525e6fab OP |
148 | if (acpi_bus_get_status(adev) || !adev->status.present || |
149 | acpi_device_enumerated(adev)) | |
150 | return -EINVAL; | |
17f4a5c4 | 151 | |
525e6fab OP |
152 | memset(info, 0, sizeof(*info)); |
153 | info->fwnode = acpi_fwnode_handle(adev); | |
17f4a5c4 | 154 | |
166c2ba3 | 155 | memset(&lookup, 0, sizeof(lookup)); |
525e6fab OP |
156 | lookup.device_handle = acpi_device_handle(adev); |
157 | lookup.info = info; | |
166c2ba3 | 158 | |
525e6fab | 159 | /* Look up for I2cSerialBus resource */ |
17f4a5c4 WS |
160 | INIT_LIST_HEAD(&resource_list); |
161 | ret = acpi_dev_get_resources(adev, &resource_list, | |
525e6fab | 162 | acpi_i2c_fill_info, &lookup); |
17f4a5c4 WS |
163 | acpi_dev_free_resource_list(&resource_list); |
164 | ||
525e6fab OP |
165 | if (ret < 0 || !info->addr) |
166 | return -EINVAL; | |
167 | ||
168 | *adapter_handle = lookup.adapter_handle; | |
17f4a5c4 | 169 | |
166c2ba3 MW |
170 | /* Then fill IRQ number if any */ |
171 | ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL); | |
172 | if (ret < 0) | |
525e6fab | 173 | return -EINVAL; |
166c2ba3 MW |
174 | |
175 | resource_list_for_each_entry(entry, &resource_list) { | |
176 | if (resource_type(entry->res) == IORESOURCE_IRQ) { | |
525e6fab | 177 | info->irq = entry->res->start; |
166c2ba3 MW |
178 | break; |
179 | } | |
180 | } | |
181 | ||
182 | acpi_dev_free_resource_list(&resource_list); | |
183 | ||
525e6fab OP |
184 | strlcpy(info->type, dev_name(&adev->dev), sizeof(info->type)); |
185 | ||
186 | return 0; | |
187 | } | |
188 | ||
189 | static void acpi_i2c_register_device(struct i2c_adapter *adapter, | |
190 | struct acpi_device *adev, | |
191 | struct i2c_board_info *info) | |
192 | { | |
17f4a5c4 | 193 | adev->power.flags.ignore_parent = true; |
525e6fab OP |
194 | acpi_device_set_enumerated(adev); |
195 | ||
196 | if (!i2c_new_device(adapter, info)) { | |
17f4a5c4 WS |
197 | adev->power.flags.ignore_parent = false; |
198 | dev_err(&adapter->dev, | |
199 | "failed to add I2C device %s from ACPI\n", | |
200 | dev_name(&adev->dev)); | |
201 | } | |
525e6fab OP |
202 | } |
203 | ||
204 | static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level, | |
205 | void *data, void **return_value) | |
206 | { | |
207 | struct i2c_adapter *adapter = data; | |
208 | struct acpi_device *adev; | |
209 | acpi_handle adapter_handle; | |
210 | struct i2c_board_info info; | |
211 | ||
212 | if (acpi_bus_get_device(handle, &adev)) | |
213 | return AE_OK; | |
214 | ||
215 | if (acpi_i2c_get_info(adev, &info, &adapter_handle)) | |
216 | return AE_OK; | |
217 | ||
218 | if (adapter_handle != ACPI_HANDLE(&adapter->dev)) | |
219 | return AE_OK; | |
220 | ||
221 | acpi_i2c_register_device(adapter, adev, &info); | |
17f4a5c4 WS |
222 | |
223 | return AE_OK; | |
224 | } | |
225 | ||
166c2ba3 MW |
226 | #define ACPI_I2C_MAX_SCAN_DEPTH 32 |
227 | ||
17f4a5c4 WS |
228 | /** |
229 | * acpi_i2c_register_devices - enumerate I2C slave devices behind adapter | |
230 | * @adap: pointer to adapter | |
231 | * | |
232 | * Enumerate all I2C slave devices behind this adapter by walking the ACPI | |
233 | * namespace. When a device is found it will be added to the Linux device | |
234 | * model and bound to the corresponding ACPI handle. | |
235 | */ | |
236 | static void acpi_i2c_register_devices(struct i2c_adapter *adap) | |
237 | { | |
17f4a5c4 WS |
238 | acpi_status status; |
239 | ||
8eb5c87a | 240 | if (!has_acpi_companion(&adap->dev)) |
17f4a5c4 WS |
241 | return; |
242 | ||
166c2ba3 MW |
243 | status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, |
244 | ACPI_I2C_MAX_SCAN_DEPTH, | |
17f4a5c4 WS |
245 | acpi_i2c_add_device, NULL, |
246 | adap, NULL); | |
247 | if (ACPI_FAILURE(status)) | |
248 | dev_warn(&adap->dev, "failed to enumerate I2C slaves\n"); | |
249 | } | |
250 | ||
525e6fab OP |
251 | static int acpi_i2c_match_adapter(struct device *dev, void *data) |
252 | { | |
253 | struct i2c_adapter *adapter = i2c_verify_adapter(dev); | |
254 | ||
255 | if (!adapter) | |
256 | return 0; | |
257 | ||
258 | return ACPI_HANDLE(dev) == (acpi_handle)data; | |
259 | } | |
260 | ||
261 | static int acpi_i2c_match_device(struct device *dev, void *data) | |
262 | { | |
263 | return ACPI_COMPANION(dev) == data; | |
264 | } | |
265 | ||
266 | static struct i2c_adapter *acpi_i2c_find_adapter_by_handle(acpi_handle handle) | |
267 | { | |
268 | struct device *dev; | |
269 | ||
270 | dev = bus_find_device(&i2c_bus_type, NULL, handle, | |
271 | acpi_i2c_match_adapter); | |
272 | return dev ? i2c_verify_adapter(dev) : NULL; | |
273 | } | |
274 | ||
275 | static struct i2c_client *acpi_i2c_find_client_by_adev(struct acpi_device *adev) | |
276 | { | |
277 | struct device *dev; | |
278 | ||
279 | dev = bus_find_device(&i2c_bus_type, NULL, adev, acpi_i2c_match_device); | |
280 | return dev ? i2c_verify_client(dev) : NULL; | |
281 | } | |
282 | ||
283 | static int acpi_i2c_notify(struct notifier_block *nb, unsigned long value, | |
284 | void *arg) | |
285 | { | |
286 | struct acpi_device *adev = arg; | |
287 | struct i2c_board_info info; | |
288 | acpi_handle adapter_handle; | |
289 | struct i2c_adapter *adapter; | |
290 | struct i2c_client *client; | |
291 | ||
292 | switch (value) { | |
293 | case ACPI_RECONFIG_DEVICE_ADD: | |
294 | if (acpi_i2c_get_info(adev, &info, &adapter_handle)) | |
295 | break; | |
296 | ||
297 | adapter = acpi_i2c_find_adapter_by_handle(adapter_handle); | |
298 | if (!adapter) | |
299 | break; | |
300 | ||
301 | acpi_i2c_register_device(adapter, adev, &info); | |
302 | break; | |
303 | case ACPI_RECONFIG_DEVICE_REMOVE: | |
304 | if (!acpi_device_enumerated(adev)) | |
305 | break; | |
306 | ||
307 | client = acpi_i2c_find_client_by_adev(adev); | |
308 | if (!client) | |
309 | break; | |
310 | ||
311 | i2c_unregister_device(client); | |
312 | put_device(&client->dev); | |
313 | break; | |
314 | } | |
315 | ||
316 | return NOTIFY_OK; | |
317 | } | |
318 | ||
319 | static struct notifier_block i2c_acpi_notifier = { | |
320 | .notifier_call = acpi_i2c_notify, | |
321 | }; | |
17f4a5c4 WS |
322 | #else /* CONFIG_ACPI */ |
323 | static inline void acpi_i2c_register_devices(struct i2c_adapter *adap) { } | |
525e6fab | 324 | extern struct notifier_block i2c_acpi_notifier; |
17f4a5c4 WS |
325 | #endif /* CONFIG_ACPI */ |
326 | ||
327 | #ifdef CONFIG_ACPI_I2C_OPREGION | |
328 | static int acpi_gsb_i2c_read_bytes(struct i2c_client *client, | |
329 | u8 cmd, u8 *data, u8 data_len) | |
330 | { | |
331 | ||
332 | struct i2c_msg msgs[2]; | |
333 | int ret; | |
334 | u8 *buffer; | |
335 | ||
336 | buffer = kzalloc(data_len, GFP_KERNEL); | |
337 | if (!buffer) | |
338 | return AE_NO_MEMORY; | |
339 | ||
340 | msgs[0].addr = client->addr; | |
341 | msgs[0].flags = client->flags; | |
342 | msgs[0].len = 1; | |
343 | msgs[0].buf = &cmd; | |
344 | ||
345 | msgs[1].addr = client->addr; | |
346 | msgs[1].flags = client->flags | I2C_M_RD; | |
347 | msgs[1].len = data_len; | |
348 | msgs[1].buf = buffer; | |
349 | ||
350 | ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); | |
351 | if (ret < 0) | |
352 | dev_err(&client->adapter->dev, "i2c read failed\n"); | |
353 | else | |
354 | memcpy(data, buffer, data_len); | |
355 | ||
356 | kfree(buffer); | |
357 | return ret; | |
358 | } | |
359 | ||
360 | static int acpi_gsb_i2c_write_bytes(struct i2c_client *client, | |
361 | u8 cmd, u8 *data, u8 data_len) | |
362 | { | |
363 | ||
364 | struct i2c_msg msgs[1]; | |
365 | u8 *buffer; | |
366 | int ret = AE_OK; | |
367 | ||
368 | buffer = kzalloc(data_len + 1, GFP_KERNEL); | |
369 | if (!buffer) | |
370 | return AE_NO_MEMORY; | |
371 | ||
372 | buffer[0] = cmd; | |
373 | memcpy(buffer + 1, data, data_len); | |
374 | ||
375 | msgs[0].addr = client->addr; | |
376 | msgs[0].flags = client->flags; | |
377 | msgs[0].len = data_len + 1; | |
378 | msgs[0].buf = buffer; | |
379 | ||
380 | ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); | |
381 | if (ret < 0) | |
382 | dev_err(&client->adapter->dev, "i2c write failed\n"); | |
383 | ||
384 | kfree(buffer); | |
385 | return ret; | |
386 | } | |
387 | ||
388 | static acpi_status | |
389 | acpi_i2c_space_handler(u32 function, acpi_physical_address command, | |
390 | u32 bits, u64 *value64, | |
391 | void *handler_context, void *region_context) | |
392 | { | |
393 | struct gsb_buffer *gsb = (struct gsb_buffer *)value64; | |
394 | struct acpi_i2c_handler_data *data = handler_context; | |
395 | struct acpi_connection_info *info = &data->info; | |
396 | struct acpi_resource_i2c_serialbus *sb; | |
397 | struct i2c_adapter *adapter = data->adapter; | |
7ef85f5f | 398 | struct i2c_client *client; |
17f4a5c4 WS |
399 | struct acpi_resource *ares; |
400 | u32 accessor_type = function >> 16; | |
401 | u8 action = function & ACPI_IO_MASK; | |
4470c725 | 402 | acpi_status ret; |
17f4a5c4 WS |
403 | int status; |
404 | ||
405 | ret = acpi_buffer_to_resource(info->connection, info->length, &ares); | |
406 | if (ACPI_FAILURE(ret)) | |
407 | return ret; | |
408 | ||
7ef85f5f JN |
409 | client = kzalloc(sizeof(*client), GFP_KERNEL); |
410 | if (!client) { | |
411 | ret = AE_NO_MEMORY; | |
412 | goto err; | |
413 | } | |
414 | ||
17f4a5c4 WS |
415 | if (!value64 || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) { |
416 | ret = AE_BAD_PARAMETER; | |
417 | goto err; | |
418 | } | |
419 | ||
420 | sb = &ares->data.i2c_serial_bus; | |
421 | if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) { | |
422 | ret = AE_BAD_PARAMETER; | |
423 | goto err; | |
424 | } | |
425 | ||
7ef85f5f JN |
426 | client->adapter = adapter; |
427 | client->addr = sb->slave_address; | |
17f4a5c4 WS |
428 | |
429 | if (sb->access_mode == ACPI_I2C_10BIT_MODE) | |
7ef85f5f | 430 | client->flags |= I2C_CLIENT_TEN; |
17f4a5c4 WS |
431 | |
432 | switch (accessor_type) { | |
433 | case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV: | |
434 | if (action == ACPI_READ) { | |
7ef85f5f | 435 | status = i2c_smbus_read_byte(client); |
17f4a5c4 WS |
436 | if (status >= 0) { |
437 | gsb->bdata = status; | |
438 | status = 0; | |
439 | } | |
440 | } else { | |
7ef85f5f | 441 | status = i2c_smbus_write_byte(client, gsb->bdata); |
17f4a5c4 WS |
442 | } |
443 | break; | |
444 | ||
445 | case ACPI_GSB_ACCESS_ATTRIB_BYTE: | |
446 | if (action == ACPI_READ) { | |
7ef85f5f | 447 | status = i2c_smbus_read_byte_data(client, command); |
17f4a5c4 WS |
448 | if (status >= 0) { |
449 | gsb->bdata = status; | |
450 | status = 0; | |
451 | } | |
452 | } else { | |
7ef85f5f | 453 | status = i2c_smbus_write_byte_data(client, command, |
17f4a5c4 WS |
454 | gsb->bdata); |
455 | } | |
456 | break; | |
457 | ||
458 | case ACPI_GSB_ACCESS_ATTRIB_WORD: | |
459 | if (action == ACPI_READ) { | |
7ef85f5f | 460 | status = i2c_smbus_read_word_data(client, command); |
17f4a5c4 WS |
461 | if (status >= 0) { |
462 | gsb->wdata = status; | |
463 | status = 0; | |
464 | } | |
465 | } else { | |
7ef85f5f | 466 | status = i2c_smbus_write_word_data(client, command, |
17f4a5c4 WS |
467 | gsb->wdata); |
468 | } | |
469 | break; | |
470 | ||
471 | case ACPI_GSB_ACCESS_ATTRIB_BLOCK: | |
472 | if (action == ACPI_READ) { | |
7ef85f5f | 473 | status = i2c_smbus_read_block_data(client, command, |
17f4a5c4 WS |
474 | gsb->data); |
475 | if (status >= 0) { | |
476 | gsb->len = status; | |
477 | status = 0; | |
478 | } | |
479 | } else { | |
7ef85f5f | 480 | status = i2c_smbus_write_block_data(client, command, |
17f4a5c4 WS |
481 | gsb->len, gsb->data); |
482 | } | |
483 | break; | |
484 | ||
485 | case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE: | |
486 | if (action == ACPI_READ) { | |
7ef85f5f | 487 | status = acpi_gsb_i2c_read_bytes(client, command, |
17f4a5c4 WS |
488 | gsb->data, info->access_length); |
489 | if (status > 0) | |
490 | status = 0; | |
491 | } else { | |
7ef85f5f | 492 | status = acpi_gsb_i2c_write_bytes(client, command, |
17f4a5c4 WS |
493 | gsb->data, info->access_length); |
494 | } | |
495 | break; | |
496 | ||
497 | default: | |
be309c3c WS |
498 | dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n", |
499 | accessor_type, client->addr); | |
17f4a5c4 WS |
500 | ret = AE_BAD_PARAMETER; |
501 | goto err; | |
502 | } | |
503 | ||
504 | gsb->status = status; | |
505 | ||
506 | err: | |
7ef85f5f | 507 | kfree(client); |
17f4a5c4 WS |
508 | ACPI_FREE(ares); |
509 | return ret; | |
510 | } | |
511 | ||
512 | ||
513 | static int acpi_i2c_install_space_handler(struct i2c_adapter *adapter) | |
514 | { | |
0aef44e8 | 515 | acpi_handle handle; |
17f4a5c4 WS |
516 | struct acpi_i2c_handler_data *data; |
517 | acpi_status status; | |
518 | ||
0aef44e8 PH |
519 | if (!adapter->dev.parent) |
520 | return -ENODEV; | |
521 | ||
522 | handle = ACPI_HANDLE(adapter->dev.parent); | |
523 | ||
17f4a5c4 WS |
524 | if (!handle) |
525 | return -ENODEV; | |
526 | ||
527 | data = kzalloc(sizeof(struct acpi_i2c_handler_data), | |
528 | GFP_KERNEL); | |
529 | if (!data) | |
530 | return -ENOMEM; | |
531 | ||
532 | data->adapter = adapter; | |
533 | status = acpi_bus_attach_private_data(handle, (void *)data); | |
534 | if (ACPI_FAILURE(status)) { | |
535 | kfree(data); | |
536 | return -ENOMEM; | |
537 | } | |
538 | ||
539 | status = acpi_install_address_space_handler(handle, | |
540 | ACPI_ADR_SPACE_GSBUS, | |
541 | &acpi_i2c_space_handler, | |
542 | NULL, | |
543 | data); | |
544 | if (ACPI_FAILURE(status)) { | |
545 | dev_err(&adapter->dev, "Error installing i2c space handler\n"); | |
546 | acpi_bus_detach_private_data(handle); | |
547 | kfree(data); | |
548 | return -ENOMEM; | |
549 | } | |
550 | ||
40e7fcb1 | 551 | acpi_walk_dep_device_list(handle); |
17f4a5c4 WS |
552 | return 0; |
553 | } | |
554 | ||
555 | static void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter) | |
556 | { | |
0aef44e8 | 557 | acpi_handle handle; |
17f4a5c4 WS |
558 | struct acpi_i2c_handler_data *data; |
559 | acpi_status status; | |
560 | ||
0aef44e8 PH |
561 | if (!adapter->dev.parent) |
562 | return; | |
563 | ||
564 | handle = ACPI_HANDLE(adapter->dev.parent); | |
565 | ||
17f4a5c4 WS |
566 | if (!handle) |
567 | return; | |
568 | ||
569 | acpi_remove_address_space_handler(handle, | |
570 | ACPI_ADR_SPACE_GSBUS, | |
571 | &acpi_i2c_space_handler); | |
572 | ||
573 | status = acpi_bus_get_private_data(handle, (void **)&data); | |
574 | if (ACPI_SUCCESS(status)) | |
575 | kfree(data); | |
576 | ||
577 | acpi_bus_detach_private_data(handle); | |
578 | } | |
579 | #else /* CONFIG_ACPI_I2C_OPREGION */ | |
580 | static inline void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter) | |
581 | { } | |
582 | ||
583 | static inline int acpi_i2c_install_space_handler(struct i2c_adapter *adapter) | |
584 | { return 0; } | |
585 | #endif /* CONFIG_ACPI_I2C_OPREGION */ | |
586 | ||
f37dd80a DB |
587 | /* ------------------------------------------------------------------------- */ |
588 | ||
d2653e92 JD |
589 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
590 | const struct i2c_client *client) | |
591 | { | |
592 | while (id->name[0]) { | |
593 | if (strcmp(client->name, id->name) == 0) | |
594 | return id; | |
595 | id++; | |
596 | } | |
597 | return NULL; | |
598 | } | |
599 | ||
1da177e4 LT |
600 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
601 | { | |
51298d12 JD |
602 | struct i2c_client *client = i2c_verify_client(dev); |
603 | struct i2c_driver *driver; | |
604 | ||
605 | if (!client) | |
606 | return 0; | |
7b4fbc50 | 607 | |
959e85f7 GL |
608 | /* Attempt an OF style match */ |
609 | if (of_driver_match_device(dev, drv)) | |
610 | return 1; | |
611 | ||
907ddf89 MW |
612 | /* Then ACPI style match */ |
613 | if (acpi_driver_match_device(dev, drv)) | |
614 | return 1; | |
615 | ||
51298d12 | 616 | driver = to_i2c_driver(drv); |
d2653e92 JD |
617 | /* match on an id table if there is one */ |
618 | if (driver->id_table) | |
619 | return i2c_match_id(driver->id_table, client) != NULL; | |
620 | ||
eb8a7908 | 621 | return 0; |
1da177e4 LT |
622 | } |
623 | ||
7eff2e7a | 624 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 | 625 | { |
8dcf3217 | 626 | struct i2c_client *client = to_i2c_client(dev); |
8c4ff6d0 ZR |
627 | int rc; |
628 | ||
629 | rc = acpi_device_uevent_modalias(dev, env); | |
630 | if (rc != -ENODEV) | |
631 | return rc; | |
7b4fbc50 | 632 | |
8dcf3217 | 633 | return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
634 | } |
635 | ||
5f9296ba VK |
636 | /* i2c bus recovery routines */ |
637 | static int get_scl_gpio_value(struct i2c_adapter *adap) | |
638 | { | |
639 | return gpio_get_value(adap->bus_recovery_info->scl_gpio); | |
640 | } | |
641 | ||
642 | static void set_scl_gpio_value(struct i2c_adapter *adap, int val) | |
643 | { | |
644 | gpio_set_value(adap->bus_recovery_info->scl_gpio, val); | |
645 | } | |
646 | ||
647 | static int get_sda_gpio_value(struct i2c_adapter *adap) | |
648 | { | |
649 | return gpio_get_value(adap->bus_recovery_info->sda_gpio); | |
650 | } | |
651 | ||
652 | static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap) | |
653 | { | |
654 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
655 | struct device *dev = &adap->dev; | |
656 | int ret = 0; | |
657 | ||
658 | ret = gpio_request_one(bri->scl_gpio, GPIOF_OPEN_DRAIN | | |
659 | GPIOF_OUT_INIT_HIGH, "i2c-scl"); | |
660 | if (ret) { | |
661 | dev_warn(dev, "Can't get SCL gpio: %d\n", bri->scl_gpio); | |
662 | return ret; | |
663 | } | |
664 | ||
665 | if (bri->get_sda) { | |
666 | if (gpio_request_one(bri->sda_gpio, GPIOF_IN, "i2c-sda")) { | |
667 | /* work without SDA polling */ | |
668 | dev_warn(dev, "Can't get SDA gpio: %d. Not using SDA polling\n", | |
669 | bri->sda_gpio); | |
670 | bri->get_sda = NULL; | |
671 | } | |
672 | } | |
673 | ||
674 | return ret; | |
675 | } | |
676 | ||
677 | static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap) | |
678 | { | |
679 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
680 | ||
681 | if (bri->get_sda) | |
682 | gpio_free(bri->sda_gpio); | |
683 | ||
684 | gpio_free(bri->scl_gpio); | |
685 | } | |
686 | ||
687 | /* | |
688 | * We are generating clock pulses. ndelay() determines durating of clk pulses. | |
689 | * We will generate clock with rate 100 KHz and so duration of both clock levels | |
690 | * is: delay in ns = (10^6 / 100) / 2 | |
691 | */ | |
692 | #define RECOVERY_NDELAY 5000 | |
693 | #define RECOVERY_CLK_CNT 9 | |
694 | ||
695 | static int i2c_generic_recovery(struct i2c_adapter *adap) | |
696 | { | |
697 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
698 | int i = 0, val = 1, ret = 0; | |
699 | ||
700 | if (bri->prepare_recovery) | |
2b2190a3 | 701 | bri->prepare_recovery(adap); |
5f9296ba | 702 | |
8b062608 JL |
703 | bri->set_scl(adap, val); |
704 | ndelay(RECOVERY_NDELAY); | |
705 | ||
5f9296ba VK |
706 | /* |
707 | * By this time SCL is high, as we need to give 9 falling-rising edges | |
708 | */ | |
709 | while (i++ < RECOVERY_CLK_CNT * 2) { | |
710 | if (val) { | |
711 | /* Break if SDA is high */ | |
712 | if (bri->get_sda && bri->get_sda(adap)) | |
713 | break; | |
714 | /* SCL shouldn't be low here */ | |
715 | if (!bri->get_scl(adap)) { | |
716 | dev_err(&adap->dev, | |
717 | "SCL is stuck low, exit recovery\n"); | |
718 | ret = -EBUSY; | |
719 | break; | |
720 | } | |
721 | } | |
722 | ||
723 | val = !val; | |
724 | bri->set_scl(adap, val); | |
725 | ndelay(RECOVERY_NDELAY); | |
726 | } | |
727 | ||
728 | if (bri->unprepare_recovery) | |
2b2190a3 | 729 | bri->unprepare_recovery(adap); |
5f9296ba VK |
730 | |
731 | return ret; | |
732 | } | |
733 | ||
734 | int i2c_generic_scl_recovery(struct i2c_adapter *adap) | |
735 | { | |
5f9296ba VK |
736 | return i2c_generic_recovery(adap); |
737 | } | |
c1c21f4e | 738 | EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery); |
5f9296ba VK |
739 | |
740 | int i2c_generic_gpio_recovery(struct i2c_adapter *adap) | |
741 | { | |
742 | int ret; | |
743 | ||
744 | ret = i2c_get_gpios_for_recovery(adap); | |
745 | if (ret) | |
746 | return ret; | |
747 | ||
748 | ret = i2c_generic_recovery(adap); | |
749 | i2c_put_gpios_for_recovery(adap); | |
750 | ||
751 | return ret; | |
752 | } | |
c1c21f4e | 753 | EXPORT_SYMBOL_GPL(i2c_generic_gpio_recovery); |
5f9296ba VK |
754 | |
755 | int i2c_recover_bus(struct i2c_adapter *adap) | |
756 | { | |
757 | if (!adap->bus_recovery_info) | |
758 | return -EOPNOTSUPP; | |
759 | ||
760 | dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); | |
761 | return adap->bus_recovery_info->recover_bus(adap); | |
762 | } | |
c1c21f4e | 763 | EXPORT_SYMBOL_GPL(i2c_recover_bus); |
5f9296ba | 764 | |
d3b11d83 WS |
765 | static void i2c_init_recovery(struct i2c_adapter *adap) |
766 | { | |
767 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
768 | char *err_str; | |
769 | ||
770 | if (!bri) | |
771 | return; | |
772 | ||
773 | if (!bri->recover_bus) { | |
774 | err_str = "no recover_bus() found"; | |
775 | goto err; | |
776 | } | |
777 | ||
778 | /* Generic GPIO recovery */ | |
779 | if (bri->recover_bus == i2c_generic_gpio_recovery) { | |
780 | if (!gpio_is_valid(bri->scl_gpio)) { | |
781 | err_str = "invalid SCL gpio"; | |
782 | goto err; | |
783 | } | |
784 | ||
785 | if (gpio_is_valid(bri->sda_gpio)) | |
786 | bri->get_sda = get_sda_gpio_value; | |
787 | else | |
788 | bri->get_sda = NULL; | |
789 | ||
790 | bri->get_scl = get_scl_gpio_value; | |
791 | bri->set_scl = set_scl_gpio_value; | |
792 | } else if (bri->recover_bus == i2c_generic_scl_recovery) { | |
793 | /* Generic SCL recovery */ | |
794 | if (!bri->set_scl || !bri->get_scl) { | |
795 | err_str = "no {get|set}_scl() found"; | |
796 | goto err; | |
797 | } | |
798 | } | |
799 | ||
800 | return; | |
801 | err: | |
802 | dev_err(&adap->dev, "Not using recovery: %s\n", err_str); | |
803 | adap->bus_recovery_info = NULL; | |
804 | } | |
805 | ||
f37dd80a | 806 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 807 | { |
51298d12 JD |
808 | struct i2c_client *client = i2c_verify_client(dev); |
809 | struct i2c_driver *driver; | |
50c3304a | 810 | int status; |
7b4fbc50 | 811 | |
51298d12 JD |
812 | if (!client) |
813 | return 0; | |
814 | ||
845c8770 MW |
815 | if (!client->irq) { |
816 | int irq = -ENOENT; | |
817 | ||
3fffd128 DT |
818 | if (dev->of_node) { |
819 | irq = of_irq_get_byname(dev->of_node, "irq"); | |
820 | if (irq == -EINVAL || irq == -ENODATA) | |
821 | irq = of_irq_get(dev->of_node, 0); | |
822 | } else if (ACPI_COMPANION(dev)) { | |
845c8770 | 823 | irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0); |
3fffd128 | 824 | } |
6f34be74 | 825 | if (irq == -EPROBE_DEFER) |
2fd36c55 | 826 | return irq; |
6f34be74 GU |
827 | if (irq < 0) |
828 | irq = 0; | |
2fd36c55 LP |
829 | |
830 | client->irq = irq; | |
831 | } | |
832 | ||
51298d12 | 833 | driver = to_i2c_driver(dev->driver); |
e0457442 | 834 | if (!driver->probe || !driver->id_table) |
7b4fbc50 | 835 | return -ENODEV; |
0acc2b32 | 836 | |
3fffd128 DT |
837 | if (client->flags & I2C_CLIENT_WAKE) { |
838 | int wakeirq = -ENOENT; | |
839 | ||
840 | if (dev->of_node) { | |
841 | wakeirq = of_irq_get_byname(dev->of_node, "wakeup"); | |
842 | if (wakeirq == -EPROBE_DEFER) | |
843 | return wakeirq; | |
844 | } | |
845 | ||
846 | device_init_wakeup(&client->dev, true); | |
847 | ||
848 | if (wakeirq > 0 && wakeirq != client->irq) | |
849 | status = dev_pm_set_dedicated_wake_irq(dev, wakeirq); | |
850 | else if (client->irq > 0) | |
c18fba23 | 851 | status = dev_pm_set_wake_irq(dev, client->irq); |
3fffd128 DT |
852 | else |
853 | status = 0; | |
854 | ||
855 | if (status) | |
856 | dev_warn(&client->dev, "failed to set up wakeup irq"); | |
857 | } | |
858 | ||
7b4fbc50 | 859 | dev_dbg(dev, "probe\n"); |
d2653e92 | 860 | |
86be408b SN |
861 | status = of_clk_set_defaults(dev->of_node, false); |
862 | if (status < 0) | |
3fffd128 | 863 | goto err_clear_wakeup_irq; |
86be408b | 864 | |
e09b0d4e | 865 | status = dev_pm_domain_attach(&client->dev, true); |
74cedd30 KB |
866 | if (status == -EPROBE_DEFER) |
867 | goto err_clear_wakeup_irq; | |
868 | ||
869 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); | |
870 | if (status) | |
871 | goto err_detach_pm_domain; | |
72fa818e | 872 | |
3fffd128 DT |
873 | return 0; |
874 | ||
875 | err_detach_pm_domain: | |
876 | dev_pm_domain_detach(&client->dev, true); | |
877 | err_clear_wakeup_irq: | |
878 | dev_pm_clear_wake_irq(&client->dev); | |
879 | device_init_wakeup(&client->dev, false); | |
50c3304a | 880 | return status; |
f37dd80a | 881 | } |
1da177e4 | 882 | |
f37dd80a DB |
883 | static int i2c_device_remove(struct device *dev) |
884 | { | |
51298d12 | 885 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 | 886 | struct i2c_driver *driver; |
72fa818e | 887 | int status = 0; |
a1d9e6e4 | 888 | |
51298d12 | 889 | if (!client || !dev->driver) |
a1d9e6e4 DB |
890 | return 0; |
891 | ||
892 | driver = to_i2c_driver(dev->driver); | |
893 | if (driver->remove) { | |
894 | dev_dbg(dev, "remove\n"); | |
895 | status = driver->remove(client); | |
a1d9e6e4 | 896 | } |
72fa818e | 897 | |
e09b0d4e | 898 | dev_pm_domain_detach(&client->dev, true); |
3fffd128 DT |
899 | |
900 | dev_pm_clear_wake_irq(&client->dev); | |
901 | device_init_wakeup(&client->dev, false); | |
902 | ||
a1d9e6e4 | 903 | return status; |
1da177e4 LT |
904 | } |
905 | ||
f37dd80a | 906 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 907 | { |
51298d12 | 908 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
909 | struct i2c_driver *driver; |
910 | ||
51298d12 | 911 | if (!client || !dev->driver) |
f37dd80a DB |
912 | return; |
913 | driver = to_i2c_driver(dev->driver); | |
914 | if (driver->shutdown) | |
51298d12 | 915 | driver->shutdown(client); |
1da177e4 LT |
916 | } |
917 | ||
9c1600ed DB |
918 | static void i2c_client_dev_release(struct device *dev) |
919 | { | |
920 | kfree(to_i2c_client(dev)); | |
921 | } | |
922 | ||
09b8ce0a | 923 | static ssize_t |
4f8cf824 | 924 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 925 | { |
4f8cf824 JD |
926 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
927 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 | 928 | } |
a5eb71b2 | 929 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
7b4fbc50 | 930 | |
09b8ce0a ZX |
931 | static ssize_t |
932 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
933 | { |
934 | struct i2c_client *client = to_i2c_client(dev); | |
8c4ff6d0 ZR |
935 | int len; |
936 | ||
937 | len = acpi_device_modalias(dev, buf, PAGE_SIZE -1); | |
938 | if (len != -ENODEV) | |
939 | return len; | |
940 | ||
eb8a7908 | 941 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 | 942 | } |
51298d12 JD |
943 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
944 | ||
945 | static struct attribute *i2c_dev_attrs[] = { | |
946 | &dev_attr_name.attr, | |
7b4fbc50 | 947 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
948 | &dev_attr_modalias.attr, |
949 | NULL | |
950 | }; | |
a5eb71b2 | 951 | ATTRIBUTE_GROUPS(i2c_dev); |
54067ee2 | 952 | |
e9ca9eb9 | 953 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
954 | .name = "i2c", |
955 | .match = i2c_device_match, | |
956 | .probe = i2c_device_probe, | |
957 | .remove = i2c_device_remove, | |
958 | .shutdown = i2c_device_shutdown, | |
b864c7d5 | 959 | }; |
e9ca9eb9 | 960 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 961 | |
51298d12 | 962 | static struct device_type i2c_client_type = { |
a5eb71b2 | 963 | .groups = i2c_dev_groups, |
51298d12 JD |
964 | .uevent = i2c_device_uevent, |
965 | .release = i2c_client_dev_release, | |
966 | }; | |
967 | ||
9b766b81 DB |
968 | |
969 | /** | |
970 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
971 | * @dev: device, probably from some driver model iterator | |
972 | * | |
973 | * When traversing the driver model tree, perhaps using driver model | |
974 | * iterators like @device_for_each_child(), you can't assume very much | |
975 | * about the nodes you find. Use this function to avoid oopses caused | |
976 | * by wrongly treating some non-I2C device as an i2c_client. | |
977 | */ | |
978 | struct i2c_client *i2c_verify_client(struct device *dev) | |
979 | { | |
51298d12 | 980 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
981 | ? to_i2c_client(dev) |
982 | : NULL; | |
983 | } | |
984 | EXPORT_SYMBOL(i2c_verify_client); | |
985 | ||
986 | ||
da899f55 WS |
987 | /* Return a unique address which takes the flags of the client into account */ |
988 | static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client) | |
989 | { | |
990 | unsigned short addr = client->addr; | |
991 | ||
992 | /* For some client flags, add an arbitrary offset to avoid collisions */ | |
993 | if (client->flags & I2C_CLIENT_TEN) | |
994 | addr |= I2C_ADDR_OFFSET_TEN_BIT; | |
995 | ||
996 | if (client->flags & I2C_CLIENT_SLAVE) | |
997 | addr |= I2C_ADDR_OFFSET_SLAVE; | |
998 | ||
999 | return addr; | |
1000 | } | |
1001 | ||
3a89db5f | 1002 | /* This is a permissive address validity check, I2C address map constraints |
25985edc | 1003 | * are purposely not enforced, except for the general call address. */ |
c4019b70 | 1004 | static int i2c_check_addr_validity(unsigned addr, unsigned short flags) |
3a89db5f | 1005 | { |
c4019b70 | 1006 | if (flags & I2C_CLIENT_TEN) { |
3a89db5f | 1007 | /* 10-bit address, all values are valid */ |
c4019b70 | 1008 | if (addr > 0x3ff) |
3a89db5f JD |
1009 | return -EINVAL; |
1010 | } else { | |
1011 | /* 7-bit address, reject the general call address */ | |
c4019b70 | 1012 | if (addr == 0x00 || addr > 0x7f) |
3a89db5f JD |
1013 | return -EINVAL; |
1014 | } | |
1015 | return 0; | |
1016 | } | |
1017 | ||
656b8761 JD |
1018 | /* And this is a strict address validity check, used when probing. If a |
1019 | * device uses a reserved address, then it shouldn't be probed. 7-bit | |
1020 | * addressing is assumed, 10-bit address devices are rare and should be | |
1021 | * explicitly enumerated. */ | |
66be6056 | 1022 | static int i2c_check_7bit_addr_validity_strict(unsigned short addr) |
656b8761 JD |
1023 | { |
1024 | /* | |
1025 | * Reserved addresses per I2C specification: | |
1026 | * 0x00 General call address / START byte | |
1027 | * 0x01 CBUS address | |
1028 | * 0x02 Reserved for different bus format | |
1029 | * 0x03 Reserved for future purposes | |
1030 | * 0x04-0x07 Hs-mode master code | |
1031 | * 0x78-0x7b 10-bit slave addressing | |
1032 | * 0x7c-0x7f Reserved for future purposes | |
1033 | */ | |
1034 | if (addr < 0x08 || addr > 0x77) | |
1035 | return -EINVAL; | |
1036 | return 0; | |
1037 | } | |
1038 | ||
3b5f794b JD |
1039 | static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
1040 | { | |
1041 | struct i2c_client *client = i2c_verify_client(dev); | |
1042 | int addr = *(int *)addrp; | |
1043 | ||
9bccc70a | 1044 | if (client && i2c_encode_flags_to_addr(client) == addr) |
3b5f794b JD |
1045 | return -EBUSY; |
1046 | return 0; | |
1047 | } | |
1048 | ||
0826374b ML |
1049 | /* walk up mux tree */ |
1050 | static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
1051 | { | |
97cc4d49 | 1052 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
1053 | int result; |
1054 | ||
1055 | result = device_for_each_child(&adapter->dev, &addr, | |
1056 | __i2c_check_addr_busy); | |
1057 | ||
97cc4d49 JD |
1058 | if (!result && parent) |
1059 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
1060 | |
1061 | return result; | |
1062 | } | |
1063 | ||
1064 | /* recurse down mux tree */ | |
1065 | static int i2c_check_mux_children(struct device *dev, void *addrp) | |
1066 | { | |
1067 | int result; | |
1068 | ||
1069 | if (dev->type == &i2c_adapter_type) | |
1070 | result = device_for_each_child(dev, addrp, | |
1071 | i2c_check_mux_children); | |
1072 | else | |
1073 | result = __i2c_check_addr_busy(dev, addrp); | |
1074 | ||
1075 | return result; | |
1076 | } | |
1077 | ||
3b5f794b JD |
1078 | static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) |
1079 | { | |
97cc4d49 | 1080 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
1081 | int result = 0; |
1082 | ||
97cc4d49 JD |
1083 | if (parent) |
1084 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
1085 | |
1086 | if (!result) | |
1087 | result = device_for_each_child(&adapter->dev, &addr, | |
1088 | i2c_check_mux_children); | |
1089 | ||
1090 | return result; | |
3b5f794b JD |
1091 | } |
1092 | ||
fe61e07e | 1093 | /** |
8320f495 | 1094 | * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment |
fe61e07e | 1095 | * @adapter: Target I2C bus segment |
8320f495 PR |
1096 | * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT |
1097 | * locks only this branch in the adapter tree | |
fe61e07e | 1098 | */ |
8320f495 PR |
1099 | static void i2c_adapter_lock_bus(struct i2c_adapter *adapter, |
1100 | unsigned int flags) | |
fe61e07e | 1101 | { |
fa96f0cb | 1102 | rt_mutex_lock(&adapter->bus_lock); |
fe61e07e | 1103 | } |
fe61e07e JD |
1104 | |
1105 | /** | |
8320f495 | 1106 | * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment |
fe61e07e | 1107 | * @adapter: Target I2C bus segment |
8320f495 PR |
1108 | * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT |
1109 | * trylocks only this branch in the adapter tree | |
fe61e07e | 1110 | */ |
8320f495 PR |
1111 | static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter, |
1112 | unsigned int flags) | |
fe61e07e | 1113 | { |
fa96f0cb | 1114 | return rt_mutex_trylock(&adapter->bus_lock); |
fe61e07e JD |
1115 | } |
1116 | ||
1117 | /** | |
8320f495 | 1118 | * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment |
fe61e07e | 1119 | * @adapter: Target I2C bus segment |
8320f495 PR |
1120 | * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT |
1121 | * unlocks only this branch in the adapter tree | |
fe61e07e | 1122 | */ |
8320f495 PR |
1123 | static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter, |
1124 | unsigned int flags) | |
fe61e07e | 1125 | { |
fa96f0cb | 1126 | rt_mutex_unlock(&adapter->bus_lock); |
fe61e07e | 1127 | } |
fe61e07e | 1128 | |
70762abb JN |
1129 | static void i2c_dev_set_name(struct i2c_adapter *adap, |
1130 | struct i2c_client *client) | |
1131 | { | |
1132 | struct acpi_device *adev = ACPI_COMPANION(&client->dev); | |
1133 | ||
1134 | if (adev) { | |
1135 | dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); | |
1136 | return; | |
1137 | } | |
1138 | ||
70762abb | 1139 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), |
da899f55 | 1140 | i2c_encode_flags_to_addr(client)); |
70762abb JN |
1141 | } |
1142 | ||
9c1600ed | 1143 | /** |
f8a227e8 | 1144 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
1145 | * @adap: the adapter managing the device |
1146 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 1147 | * Context: can sleep |
9c1600ed | 1148 | * |
f8a227e8 JD |
1149 | * Create an i2c device. Binding is handled through driver model |
1150 | * probe()/remove() methods. A driver may be bound to this device when we | |
1151 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
1152 | * load the driver module). This call is not appropriate for use by mainboard | |
1153 | * initialization logic, which usually runs during an arch_initcall() long | |
1154 | * before any i2c_adapter could exist. | |
9c1600ed DB |
1155 | * |
1156 | * This returns the new i2c client, which may be saved for later use with | |
1157 | * i2c_unregister_device(); or NULL to indicate an error. | |
1158 | */ | |
1159 | struct i2c_client * | |
1160 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
1161 | { | |
1162 | struct i2c_client *client; | |
1163 | int status; | |
1164 | ||
1165 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
1166 | if (!client) | |
1167 | return NULL; | |
1168 | ||
1169 | client->adapter = adap; | |
1170 | ||
1171 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 1172 | |
11f1f2af AV |
1173 | if (info->archdata) |
1174 | client->dev.archdata = *info->archdata; | |
1175 | ||
ee35425c | 1176 | client->flags = info->flags; |
9c1600ed DB |
1177 | client->addr = info->addr; |
1178 | client->irq = info->irq; | |
1179 | ||
9c1600ed DB |
1180 | strlcpy(client->name, info->type, sizeof(client->name)); |
1181 | ||
c4019b70 | 1182 | status = i2c_check_addr_validity(client->addr, client->flags); |
3a89db5f JD |
1183 | if (status) { |
1184 | dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", | |
1185 | client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); | |
1186 | goto out_err_silent; | |
1187 | } | |
1188 | ||
f8a227e8 | 1189 | /* Check for address business */ |
9bccc70a | 1190 | status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client)); |
f8a227e8 JD |
1191 | if (status) |
1192 | goto out_err; | |
1193 | ||
1194 | client->dev.parent = &client->adapter->dev; | |
1195 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 1196 | client->dev.type = &i2c_client_type; |
d12d42f7 | 1197 | client->dev.of_node = info->of_node; |
ce793486 | 1198 | client->dev.fwnode = info->fwnode; |
f8a227e8 | 1199 | |
70762abb | 1200 | i2c_dev_set_name(adap, client); |
f8a227e8 JD |
1201 | status = device_register(&client->dev); |
1202 | if (status) | |
1203 | goto out_err; | |
1204 | ||
f8a227e8 JD |
1205 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
1206 | client->name, dev_name(&client->dev)); | |
1207 | ||
9c1600ed | 1208 | return client; |
f8a227e8 JD |
1209 | |
1210 | out_err: | |
1211 | dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " | |
1212 | "(%d)\n", client->name, client->addr, status); | |
3a89db5f | 1213 | out_err_silent: |
f8a227e8 JD |
1214 | kfree(client); |
1215 | return NULL; | |
9c1600ed DB |
1216 | } |
1217 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
1218 | ||
1219 | ||
1220 | /** | |
1221 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
1222 | * @client: value returned from i2c_new_device() | |
d64f73be | 1223 | * Context: can sleep |
9c1600ed DB |
1224 | */ |
1225 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 1226 | { |
4f001fd3 PA |
1227 | if (client->dev.of_node) |
1228 | of_node_clear_flag(client->dev.of_node, OF_POPULATED); | |
525e6fab OP |
1229 | if (ACPI_COMPANION(&client->dev)) |
1230 | acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev)); | |
a1d9e6e4 DB |
1231 | device_unregister(&client->dev); |
1232 | } | |
9c1600ed | 1233 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
1234 | |
1235 | ||
60b129d7 JD |
1236 | static const struct i2c_device_id dummy_id[] = { |
1237 | { "dummy", 0 }, | |
1238 | { }, | |
1239 | }; | |
1240 | ||
d2653e92 JD |
1241 | static int dummy_probe(struct i2c_client *client, |
1242 | const struct i2c_device_id *id) | |
1243 | { | |
1244 | return 0; | |
1245 | } | |
1246 | ||
1247 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
1248 | { |
1249 | return 0; | |
1250 | } | |
1251 | ||
1252 | static struct i2c_driver dummy_driver = { | |
1253 | .driver.name = "dummy", | |
d2653e92 JD |
1254 | .probe = dummy_probe, |
1255 | .remove = dummy_remove, | |
60b129d7 | 1256 | .id_table = dummy_id, |
e9f1373b DB |
1257 | }; |
1258 | ||
1259 | /** | |
1260 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
1261 | * @adapter: the adapter managing the device | |
1262 | * @address: seven bit address to be used | |
e9f1373b DB |
1263 | * Context: can sleep |
1264 | * | |
1265 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
1266 | * with devices that consume multiple addresses. Examples of such chips | |
1267 | * include various EEPROMS (like 24c04 and 24c08 models). | |
1268 | * | |
1269 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
1270 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
1271 | * And second, this prevents the specified address from being bound to a | |
1272 | * different driver. | |
1273 | * | |
1274 | * This returns the new i2c client, which should be saved for later use with | |
1275 | * i2c_unregister_device(); or NULL to indicate an error. | |
1276 | */ | |
09b8ce0a | 1277 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
1278 | { |
1279 | struct i2c_board_info info = { | |
60b129d7 | 1280 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
1281 | }; |
1282 | ||
e9f1373b DB |
1283 | return i2c_new_device(adapter, &info); |
1284 | } | |
1285 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
1286 | ||
0f614d83 JMH |
1287 | /** |
1288 | * i2c_new_secondary_device - Helper to get the instantiated secondary address | |
1289 | * and create the associated device | |
1290 | * @client: Handle to the primary client | |
1291 | * @name: Handle to specify which secondary address to get | |
1292 | * @default_addr: Used as a fallback if no secondary address was specified | |
1293 | * Context: can sleep | |
1294 | * | |
1295 | * I2C clients can be composed of multiple I2C slaves bound together in a single | |
1296 | * component. The I2C client driver then binds to the master I2C slave and needs | |
1297 | * to create I2C dummy clients to communicate with all the other slaves. | |
1298 | * | |
1299 | * This function creates and returns an I2C dummy client whose I2C address is | |
1300 | * retrieved from the platform firmware based on the given slave name. If no | |
1301 | * address is specified by the firmware default_addr is used. | |
1302 | * | |
1303 | * On DT-based platforms the address is retrieved from the "reg" property entry | |
1304 | * cell whose "reg-names" value matches the slave name. | |
1305 | * | |
1306 | * This returns the new i2c client, which should be saved for later use with | |
1307 | * i2c_unregister_device(); or NULL to indicate an error. | |
1308 | */ | |
1309 | struct i2c_client *i2c_new_secondary_device(struct i2c_client *client, | |
1310 | const char *name, | |
1311 | u16 default_addr) | |
1312 | { | |
1313 | struct device_node *np = client->dev.of_node; | |
1314 | u32 addr = default_addr; | |
1315 | int i; | |
1316 | ||
1317 | if (np) { | |
1318 | i = of_property_match_string(np, "reg-names", name); | |
1319 | if (i >= 0) | |
1320 | of_property_read_u32_index(np, "reg", i, &addr); | |
1321 | } | |
1322 | ||
1323 | dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr); | |
1324 | return i2c_new_dummy(client->adapter, addr); | |
1325 | } | |
1326 | EXPORT_SYMBOL_GPL(i2c_new_secondary_device); | |
1327 | ||
f37dd80a DB |
1328 | /* ------------------------------------------------------------------------- */ |
1329 | ||
16ffadfc DB |
1330 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
1331 | ||
83eaaed0 | 1332 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 1333 | { |
ef2c8321 | 1334 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
1335 | complete(&adap->dev_released); |
1336 | } | |
1337 | ||
390946b1 JD |
1338 | /* |
1339 | * This function is only needed for mutex_lock_nested, so it is never | |
1340 | * called unless locking correctness checking is enabled. Thus we | |
1341 | * make it inline to avoid a compiler warning. That's what gcc ends up | |
1342 | * doing anyway. | |
1343 | */ | |
1344 | static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) | |
1345 | { | |
1346 | unsigned int depth = 0; | |
1347 | ||
1348 | while ((adapter = i2c_parent_is_i2c_adapter(adapter))) | |
1349 | depth++; | |
1350 | ||
1351 | return depth; | |
1352 | } | |
1353 | ||
99cd8e25 JD |
1354 | /* |
1355 | * Let users instantiate I2C devices through sysfs. This can be used when | |
1356 | * platform initialization code doesn't contain the proper data for | |
1357 | * whatever reason. Also useful for drivers that do device detection and | |
1358 | * detection fails, either because the device uses an unexpected address, | |
1359 | * or this is a compatible device with different ID register values. | |
1360 | * | |
1361 | * Parameter checking may look overzealous, but we really don't want | |
1362 | * the user to provide incorrect parameters. | |
1363 | */ | |
1364 | static ssize_t | |
1365 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
1366 | const char *buf, size_t count) | |
1367 | { | |
1368 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
1369 | struct i2c_board_info info; | |
1370 | struct i2c_client *client; | |
1371 | char *blank, end; | |
1372 | int res; | |
1373 | ||
99cd8e25 JD |
1374 | memset(&info, 0, sizeof(struct i2c_board_info)); |
1375 | ||
1376 | blank = strchr(buf, ' '); | |
1377 | if (!blank) { | |
1378 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
1379 | return -EINVAL; | |
1380 | } | |
1381 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
1382 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
1383 | return -EINVAL; | |
1384 | } | |
1385 | memcpy(info.type, buf, blank - buf); | |
1386 | ||
1387 | /* Parse remaining parameters, reject extra parameters */ | |
1388 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
1389 | if (res < 1) { | |
1390 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
1391 | return -EINVAL; | |
1392 | } | |
1393 | if (res > 1 && end != '\n') { | |
1394 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
1395 | return -EINVAL; | |
1396 | } | |
1397 | ||
cfa0327b WS |
1398 | if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) { |
1399 | info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT; | |
1400 | info.flags |= I2C_CLIENT_TEN; | |
1401 | } | |
1402 | ||
1403 | if (info.addr & I2C_ADDR_OFFSET_SLAVE) { | |
1404 | info.addr &= ~I2C_ADDR_OFFSET_SLAVE; | |
1405 | info.flags |= I2C_CLIENT_SLAVE; | |
1406 | } | |
1407 | ||
99cd8e25 JD |
1408 | client = i2c_new_device(adap, &info); |
1409 | if (!client) | |
3a89db5f | 1410 | return -EINVAL; |
99cd8e25 JD |
1411 | |
1412 | /* Keep track of the added device */ | |
dafc50d1 | 1413 | mutex_lock(&adap->userspace_clients_lock); |
6629dcff | 1414 | list_add_tail(&client->detected, &adap->userspace_clients); |
dafc50d1 | 1415 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
1416 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
1417 | info.type, info.addr); | |
1418 | ||
1419 | return count; | |
1420 | } | |
a5eb71b2 | 1421 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
99cd8e25 JD |
1422 | |
1423 | /* | |
1424 | * And of course let the users delete the devices they instantiated, if | |
1425 | * they got it wrong. This interface can only be used to delete devices | |
1426 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
1427 | * don't delete devices to which some kernel code still has references. | |
1428 | * | |
1429 | * Parameter checking may look overzealous, but we really don't want | |
1430 | * the user to delete the wrong device. | |
1431 | */ | |
1432 | static ssize_t | |
1433 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
1434 | const char *buf, size_t count) | |
1435 | { | |
1436 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
1437 | struct i2c_client *client, *next; | |
1438 | unsigned short addr; | |
1439 | char end; | |
1440 | int res; | |
1441 | ||
1442 | /* Parse parameters, reject extra parameters */ | |
1443 | res = sscanf(buf, "%hi%c", &addr, &end); | |
1444 | if (res < 1) { | |
1445 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
1446 | return -EINVAL; | |
1447 | } | |
1448 | if (res > 1 && end != '\n') { | |
1449 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
1450 | return -EINVAL; | |
1451 | } | |
1452 | ||
1453 | /* Make sure the device was added through sysfs */ | |
1454 | res = -ENOENT; | |
390946b1 JD |
1455 | mutex_lock_nested(&adap->userspace_clients_lock, |
1456 | i2c_adapter_depth(adap)); | |
6629dcff JD |
1457 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1458 | detected) { | |
cfa0327b | 1459 | if (i2c_encode_flags_to_addr(client) == addr) { |
99cd8e25 JD |
1460 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
1461 | "delete_device", client->name, client->addr); | |
1462 | ||
1463 | list_del(&client->detected); | |
1464 | i2c_unregister_device(client); | |
1465 | res = count; | |
1466 | break; | |
1467 | } | |
1468 | } | |
dafc50d1 | 1469 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
1470 | |
1471 | if (res < 0) | |
1472 | dev_err(dev, "%s: Can't find device in list\n", | |
1473 | "delete_device"); | |
1474 | return res; | |
1475 | } | |
e9b526fe AS |
1476 | static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, |
1477 | i2c_sysfs_delete_device); | |
4f8cf824 JD |
1478 | |
1479 | static struct attribute *i2c_adapter_attrs[] = { | |
1480 | &dev_attr_name.attr, | |
1481 | &dev_attr_new_device.attr, | |
1482 | &dev_attr_delete_device.attr, | |
1483 | NULL | |
1484 | }; | |
a5eb71b2 | 1485 | ATTRIBUTE_GROUPS(i2c_adapter); |
b119dc3f | 1486 | |
0826374b | 1487 | struct device_type i2c_adapter_type = { |
a5eb71b2 | 1488 | .groups = i2c_adapter_groups, |
4f8cf824 | 1489 | .release = i2c_adapter_dev_release, |
1da177e4 | 1490 | }; |
0826374b | 1491 | EXPORT_SYMBOL_GPL(i2c_adapter_type); |
1da177e4 | 1492 | |
643dd09e SW |
1493 | /** |
1494 | * i2c_verify_adapter - return parameter as i2c_adapter or NULL | |
1495 | * @dev: device, probably from some driver model iterator | |
1496 | * | |
1497 | * When traversing the driver model tree, perhaps using driver model | |
1498 | * iterators like @device_for_each_child(), you can't assume very much | |
1499 | * about the nodes you find. Use this function to avoid oopses caused | |
1500 | * by wrongly treating some non-I2C device as an i2c_adapter. | |
1501 | */ | |
1502 | struct i2c_adapter *i2c_verify_adapter(struct device *dev) | |
1503 | { | |
1504 | return (dev->type == &i2c_adapter_type) | |
1505 | ? to_i2c_adapter(dev) | |
1506 | : NULL; | |
1507 | } | |
1508 | EXPORT_SYMBOL(i2c_verify_adapter); | |
1509 | ||
2bb5095a JD |
1510 | #ifdef CONFIG_I2C_COMPAT |
1511 | static struct class_compat *i2c_adapter_compat_class; | |
1512 | #endif | |
1513 | ||
9c1600ed DB |
1514 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
1515 | { | |
1516 | struct i2c_devinfo *devinfo; | |
1517 | ||
f18c41da | 1518 | down_read(&__i2c_board_lock); |
9c1600ed DB |
1519 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
1520 | if (devinfo->busnum == adapter->nr | |
1521 | && !i2c_new_device(adapter, | |
1522 | &devinfo->board_info)) | |
09b8ce0a ZX |
1523 | dev_err(&adapter->dev, |
1524 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
1525 | devinfo->board_info.addr); |
1526 | } | |
f18c41da | 1527 | up_read(&__i2c_board_lock); |
9c1600ed DB |
1528 | } |
1529 | ||
687b81d0 WS |
1530 | /* OF support code */ |
1531 | ||
1532 | #if IS_ENABLED(CONFIG_OF) | |
a430a345 PA |
1533 | static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap, |
1534 | struct device_node *node) | |
687b81d0 | 1535 | { |
a430a345 PA |
1536 | struct i2c_client *result; |
1537 | struct i2c_board_info info = {}; | |
1538 | struct dev_archdata dev_ad = {}; | |
b4e2f6ac WS |
1539 | const __be32 *addr_be; |
1540 | u32 addr; | |
a430a345 | 1541 | int len; |
687b81d0 | 1542 | |
a430a345 | 1543 | dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name); |
687b81d0 | 1544 | |
a430a345 PA |
1545 | if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) { |
1546 | dev_err(&adap->dev, "of_i2c: modalias failure on %s\n", | |
1547 | node->full_name); | |
1548 | return ERR_PTR(-EINVAL); | |
1549 | } | |
687b81d0 | 1550 | |
b4e2f6ac WS |
1551 | addr_be = of_get_property(node, "reg", &len); |
1552 | if (!addr_be || (len < sizeof(*addr_be))) { | |
a430a345 PA |
1553 | dev_err(&adap->dev, "of_i2c: invalid reg on %s\n", |
1554 | node->full_name); | |
1555 | return ERR_PTR(-EINVAL); | |
1556 | } | |
687b81d0 | 1557 | |
b4e2f6ac WS |
1558 | addr = be32_to_cpup(addr_be); |
1559 | if (addr & I2C_TEN_BIT_ADDRESS) { | |
1560 | addr &= ~I2C_TEN_BIT_ADDRESS; | |
1561 | info.flags |= I2C_CLIENT_TEN; | |
1562 | } | |
1563 | ||
1564 | if (addr & I2C_OWN_SLAVE_ADDRESS) { | |
1565 | addr &= ~I2C_OWN_SLAVE_ADDRESS; | |
1566 | info.flags |= I2C_CLIENT_SLAVE; | |
1567 | } | |
1568 | ||
1569 | if (i2c_check_addr_validity(addr, info.flags)) { | |
a430a345 PA |
1570 | dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n", |
1571 | info.addr, node->full_name); | |
1572 | return ERR_PTR(-EINVAL); | |
1573 | } | |
687b81d0 | 1574 | |
b4e2f6ac | 1575 | info.addr = addr; |
a430a345 PA |
1576 | info.of_node = of_node_get(node); |
1577 | info.archdata = &dev_ad; | |
687b81d0 | 1578 | |
a430a345 PA |
1579 | if (of_get_property(node, "wakeup-source", NULL)) |
1580 | info.flags |= I2C_CLIENT_WAKE; | |
687b81d0 | 1581 | |
a430a345 PA |
1582 | result = i2c_new_device(adap, &info); |
1583 | if (result == NULL) { | |
1584 | dev_err(&adap->dev, "of_i2c: Failure registering %s\n", | |
1585 | node->full_name); | |
1586 | of_node_put(node); | |
a430a345 PA |
1587 | return ERR_PTR(-EINVAL); |
1588 | } | |
1589 | return result; | |
1590 | } | |
687b81d0 | 1591 | |
a430a345 PA |
1592 | static void of_i2c_register_devices(struct i2c_adapter *adap) |
1593 | { | |
1594 | struct device_node *node; | |
687b81d0 | 1595 | |
a430a345 PA |
1596 | /* Only register child devices if the adapter has a node pointer set */ |
1597 | if (!adap->dev.of_node) | |
1598 | return; | |
687b81d0 | 1599 | |
a430a345 PA |
1600 | dev_dbg(&adap->dev, "of_i2c: walking child nodes\n"); |
1601 | ||
4f001fd3 PA |
1602 | for_each_available_child_of_node(adap->dev.of_node, node) { |
1603 | if (of_node_test_and_set_flag(node, OF_POPULATED)) | |
1604 | continue; | |
a430a345 | 1605 | of_i2c_register_device(adap, node); |
4f001fd3 | 1606 | } |
687b81d0 WS |
1607 | } |
1608 | ||
1609 | static int of_dev_node_match(struct device *dev, void *data) | |
1610 | { | |
1611 | return dev->of_node == data; | |
1612 | } | |
1613 | ||
1614 | /* must call put_device() when done with returned i2c_client device */ | |
1615 | struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) | |
1616 | { | |
1617 | struct device *dev; | |
e3311469 | 1618 | struct i2c_client *client; |
687b81d0 | 1619 | |
e3311469 | 1620 | dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match); |
687b81d0 WS |
1621 | if (!dev) |
1622 | return NULL; | |
1623 | ||
e3311469 VZ |
1624 | client = i2c_verify_client(dev); |
1625 | if (!client) | |
1626 | put_device(dev); | |
1627 | ||
1628 | return client; | |
687b81d0 WS |
1629 | } |
1630 | EXPORT_SYMBOL(of_find_i2c_device_by_node); | |
1631 | ||
1632 | /* must call put_device() when done with returned i2c_adapter device */ | |
1633 | struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) | |
1634 | { | |
1635 | struct device *dev; | |
e3311469 | 1636 | struct i2c_adapter *adapter; |
687b81d0 | 1637 | |
e3311469 | 1638 | dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match); |
687b81d0 WS |
1639 | if (!dev) |
1640 | return NULL; | |
1641 | ||
e3311469 VZ |
1642 | adapter = i2c_verify_adapter(dev); |
1643 | if (!adapter) | |
1644 | put_device(dev); | |
1645 | ||
1646 | return adapter; | |
687b81d0 WS |
1647 | } |
1648 | EXPORT_SYMBOL(of_find_i2c_adapter_by_node); | |
48e9743d VZ |
1649 | |
1650 | /* must call i2c_put_adapter() when done with returned i2c_adapter device */ | |
1651 | struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) | |
1652 | { | |
1653 | struct i2c_adapter *adapter; | |
1654 | ||
1655 | adapter = of_find_i2c_adapter_by_node(node); | |
1656 | if (!adapter) | |
1657 | return NULL; | |
1658 | ||
1659 | if (!try_module_get(adapter->owner)) { | |
1660 | put_device(&adapter->dev); | |
1661 | adapter = NULL; | |
1662 | } | |
1663 | ||
1664 | return adapter; | |
1665 | } | |
1666 | EXPORT_SYMBOL(of_get_i2c_adapter_by_node); | |
687b81d0 WS |
1667 | #else |
1668 | static void of_i2c_register_devices(struct i2c_adapter *adap) { } | |
1669 | #endif /* CONFIG_OF */ | |
1670 | ||
69b0089a JD |
1671 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
1672 | struct i2c_adapter *adap) | |
026526f5 | 1673 | { |
4735c98f JD |
1674 | /* Detect supported devices on that bus, and instantiate them */ |
1675 | i2c_detect(adap, driver); | |
1676 | ||
1677 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 | 1678 | if (driver->attach_adapter) { |
a920ff41 JD |
1679 | dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n", |
1680 | driver->driver.name); | |
fe6fc258 JD |
1681 | dev_warn(&adap->dev, "Please use another way to instantiate " |
1682 | "your i2c_client\n"); | |
026526f5 JD |
1683 | /* We ignore the return code; if it fails, too bad */ |
1684 | driver->attach_adapter(adap); | |
1685 | } | |
1686 | return 0; | |
1687 | } | |
1688 | ||
69b0089a JD |
1689 | static int __process_new_adapter(struct device_driver *d, void *data) |
1690 | { | |
1691 | return i2c_do_add_adapter(to_i2c_driver(d), data); | |
1692 | } | |
1693 | ||
6e13e641 | 1694 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 1695 | { |
ce0dffaf | 1696 | int res = -EINVAL; |
1da177e4 | 1697 | |
1d0b19c9 | 1698 | /* Can't register until after driver model init */ |
95026658 | 1699 | if (WARN_ON(!is_registered)) { |
35fc37f8 JD |
1700 | res = -EAGAIN; |
1701 | goto out_list; | |
1702 | } | |
1d0b19c9 | 1703 | |
2236baa7 | 1704 | /* Sanity checks */ |
8ddfe410 | 1705 | if (WARN(!adap->name[0], "i2c adapter has no name")) |
ce0dffaf | 1706 | goto out_list; |
8ddfe410 WS |
1707 | |
1708 | if (!adap->algo) { | |
44239a5a | 1709 | pr_err("adapter '%s': no algo supplied!\n", adap->name); |
ce0dffaf | 1710 | goto out_list; |
2236baa7 JD |
1711 | } |
1712 | ||
8320f495 PR |
1713 | if (!adap->lock_bus) { |
1714 | adap->lock_bus = i2c_adapter_lock_bus; | |
1715 | adap->trylock_bus = i2c_adapter_trylock_bus; | |
1716 | adap->unlock_bus = i2c_adapter_unlock_bus; | |
1717 | } | |
1718 | ||
194684e5 | 1719 | rt_mutex_init(&adap->bus_lock); |
6ef91fcc | 1720 | rt_mutex_init(&adap->mux_lock); |
dafc50d1 | 1721 | mutex_init(&adap->userspace_clients_lock); |
6629dcff | 1722 | INIT_LIST_HEAD(&adap->userspace_clients); |
1da177e4 | 1723 | |
8fcfef6e JD |
1724 | /* Set default timeout to 1 second if not already set */ |
1725 | if (adap->timeout == 0) | |
1726 | adap->timeout = HZ; | |
1727 | ||
27d9c183 | 1728 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
1729 | adap->dev.bus = &i2c_bus_type; |
1730 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 | 1731 | res = device_register(&adap->dev); |
8ddfe410 | 1732 | if (res) { |
44239a5a | 1733 | pr_err("adapter '%s': can't register device (%d)\n", adap->name, res); |
b119c6c9 | 1734 | goto out_list; |
8ddfe410 | 1735 | } |
1da177e4 | 1736 | |
b6d7b3d1 JD |
1737 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
1738 | ||
6ada5c1e | 1739 | pm_runtime_no_callbacks(&adap->dev); |
04f59143 | 1740 | pm_suspend_ignore_children(&adap->dev, true); |
9f924169 | 1741 | pm_runtime_enable(&adap->dev); |
6ada5c1e | 1742 | |
2bb5095a JD |
1743 | #ifdef CONFIG_I2C_COMPAT |
1744 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
1745 | adap->dev.parent); | |
1746 | if (res) | |
1747 | dev_warn(&adap->dev, | |
1748 | "Failed to create compatibility class link\n"); | |
1749 | #endif | |
1750 | ||
d3b11d83 | 1751 | i2c_init_recovery(adap); |
5f9296ba | 1752 | |
729d6dd5 | 1753 | /* create pre-declared device nodes */ |
687b81d0 | 1754 | of_i2c_register_devices(adap); |
55e71edb | 1755 | acpi_i2c_register_devices(adap); |
5d98e61d | 1756 | acpi_i2c_install_space_handler(adap); |
687b81d0 | 1757 | |
6e13e641 DB |
1758 | if (adap->nr < __i2c_first_dynamic_bus_num) |
1759 | i2c_scan_static_board_info(adap); | |
1760 | ||
4735c98f | 1761 | /* Notify drivers */ |
35fc37f8 | 1762 | mutex_lock(&core_lock); |
d6703281 | 1763 | bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); |
caada32a | 1764 | mutex_unlock(&core_lock); |
35fc37f8 JD |
1765 | |
1766 | return 0; | |
b119c6c9 | 1767 | |
b119c6c9 | 1768 | out_list: |
35fc37f8 | 1769 | mutex_lock(&core_lock); |
b119c6c9 | 1770 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
1771 | mutex_unlock(&core_lock); |
1772 | return res; | |
1da177e4 LT |
1773 | } |
1774 | ||
ee5c2744 DA |
1775 | /** |
1776 | * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 | |
1777 | * @adap: the adapter to register (with adap->nr initialized) | |
1778 | * Context: can sleep | |
1779 | * | |
1780 | * See i2c_add_numbered_adapter() for details. | |
1781 | */ | |
1782 | static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1783 | { | |
84d0b617 | 1784 | int id; |
ee5c2744 DA |
1785 | |
1786 | mutex_lock(&core_lock); | |
84d0b617 | 1787 | id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL); |
ee5c2744 | 1788 | mutex_unlock(&core_lock); |
84d0b617 | 1789 | if (WARN(id < 0, "couldn't get idr")) |
ee5c2744 DA |
1790 | return id == -ENOSPC ? -EBUSY : id; |
1791 | ||
1792 | return i2c_register_adapter(adap); | |
1793 | } | |
1794 | ||
6e13e641 DB |
1795 | /** |
1796 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
1797 | * @adapter: the adapter to add | |
d64f73be | 1798 | * Context: can sleep |
6e13e641 DB |
1799 | * |
1800 | * This routine is used to declare an I2C adapter when its bus number | |
ee5c2744 DA |
1801 | * doesn't matter or when its bus number is specified by an dt alias. |
1802 | * Examples of bases when the bus number doesn't matter: I2C adapters | |
1803 | * dynamically added by USB links or PCI plugin cards. | |
6e13e641 DB |
1804 | * |
1805 | * When this returns zero, a new bus number was allocated and stored | |
1806 | * in adap->nr, and the specified adapter became available for clients. | |
1807 | * Otherwise, a negative errno value is returned. | |
1808 | */ | |
1809 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
1810 | { | |
ee5c2744 | 1811 | struct device *dev = &adapter->dev; |
4ae42b0f | 1812 | int id; |
6e13e641 | 1813 | |
ee5c2744 DA |
1814 | if (dev->of_node) { |
1815 | id = of_alias_get_id(dev->of_node, "i2c"); | |
1816 | if (id >= 0) { | |
1817 | adapter->nr = id; | |
1818 | return __i2c_add_numbered_adapter(adapter); | |
1819 | } | |
1820 | } | |
1821 | ||
caada32a | 1822 | mutex_lock(&core_lock); |
4ae42b0f TH |
1823 | id = idr_alloc(&i2c_adapter_idr, adapter, |
1824 | __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); | |
caada32a | 1825 | mutex_unlock(&core_lock); |
84d0b617 | 1826 | if (WARN(id < 0, "couldn't get idr")) |
4ae42b0f | 1827 | return id; |
6e13e641 DB |
1828 | |
1829 | adapter->nr = id; | |
4ae42b0f | 1830 | |
6e13e641 DB |
1831 | return i2c_register_adapter(adapter); |
1832 | } | |
1833 | EXPORT_SYMBOL(i2c_add_adapter); | |
1834 | ||
1835 | /** | |
1836 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
1837 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 1838 | * Context: can sleep |
6e13e641 DB |
1839 | * |
1840 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
1841 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
1842 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
1843 | * is used to properly configure I2C devices. |
1844 | * | |
488bf314 GL |
1845 | * If the requested bus number is set to -1, then this function will behave |
1846 | * identically to i2c_add_adapter, and will dynamically assign a bus number. | |
1847 | * | |
6e13e641 DB |
1848 | * If no devices have pre-been declared for this bus, then be sure to |
1849 | * register the adapter before any dynamically allocated ones. Otherwise | |
1850 | * the required bus ID may not be available. | |
1851 | * | |
1852 | * When this returns zero, the specified adapter became available for | |
1853 | * clients using the bus number provided in adap->nr. Also, the table | |
1854 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
1855 | * and the appropriate driver model device nodes are created. Otherwise, a | |
1856 | * negative errno value is returned. | |
1857 | */ | |
1858 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1859 | { | |
488bf314 GL |
1860 | if (adap->nr == -1) /* -1 means dynamically assign bus id */ |
1861 | return i2c_add_adapter(adap); | |
6e13e641 | 1862 | |
ee5c2744 | 1863 | return __i2c_add_numbered_adapter(adap); |
6e13e641 DB |
1864 | } |
1865 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
1866 | ||
19baba4c | 1867 | static void i2c_do_del_adapter(struct i2c_driver *driver, |
69b0089a | 1868 | struct i2c_adapter *adapter) |
026526f5 | 1869 | { |
4735c98f | 1870 | struct i2c_client *client, *_n; |
026526f5 | 1871 | |
acec211c JD |
1872 | /* Remove the devices we created ourselves as the result of hardware |
1873 | * probing (using a driver's detect method) */ | |
4735c98f JD |
1874 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
1875 | if (client->adapter == adapter) { | |
1876 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
1877 | client->name, client->addr); | |
1878 | list_del(&client->detected); | |
1879 | i2c_unregister_device(client); | |
1880 | } | |
1881 | } | |
026526f5 JD |
1882 | } |
1883 | ||
e549c2b5 | 1884 | static int __unregister_client(struct device *dev, void *dummy) |
5219bf88 JD |
1885 | { |
1886 | struct i2c_client *client = i2c_verify_client(dev); | |
1887 | if (client && strcmp(client->name, "dummy")) | |
1888 | i2c_unregister_device(client); | |
1889 | return 0; | |
1890 | } | |
1891 | ||
1892 | static int __unregister_dummy(struct device *dev, void *dummy) | |
e549c2b5 JD |
1893 | { |
1894 | struct i2c_client *client = i2c_verify_client(dev); | |
1895 | if (client) | |
1896 | i2c_unregister_device(client); | |
1897 | return 0; | |
1898 | } | |
1899 | ||
69b0089a JD |
1900 | static int __process_removed_adapter(struct device_driver *d, void *data) |
1901 | { | |
19baba4c LPC |
1902 | i2c_do_del_adapter(to_i2c_driver(d), data); |
1903 | return 0; | |
69b0089a JD |
1904 | } |
1905 | ||
d64f73be DB |
1906 | /** |
1907 | * i2c_del_adapter - unregister I2C adapter | |
1908 | * @adap: the adapter being unregistered | |
1909 | * Context: can sleep | |
1910 | * | |
1911 | * This unregisters an I2C adapter which was previously registered | |
1912 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
1913 | */ | |
71546300 | 1914 | void i2c_del_adapter(struct i2c_adapter *adap) |
1da177e4 | 1915 | { |
35fc37f8 | 1916 | struct i2c_adapter *found; |
bbd2d9c9 | 1917 | struct i2c_client *client, *next; |
1da177e4 LT |
1918 | |
1919 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
1920 | mutex_lock(&core_lock); |
1921 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
1922 | mutex_unlock(&core_lock); | |
1923 | if (found != adap) { | |
44239a5a | 1924 | pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name); |
71546300 | 1925 | return; |
1da177e4 LT |
1926 | } |
1927 | ||
5d98e61d | 1928 | acpi_i2c_remove_space_handler(adap); |
026526f5 | 1929 | /* Tell drivers about this removal */ |
35fc37f8 | 1930 | mutex_lock(&core_lock); |
19baba4c | 1931 | bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 1932 | __process_removed_adapter); |
35fc37f8 | 1933 | mutex_unlock(&core_lock); |
1da177e4 | 1934 | |
bbd2d9c9 | 1935 | /* Remove devices instantiated from sysfs */ |
390946b1 JD |
1936 | mutex_lock_nested(&adap->userspace_clients_lock, |
1937 | i2c_adapter_depth(adap)); | |
6629dcff JD |
1938 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1939 | detected) { | |
1940 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, | |
1941 | client->addr); | |
1942 | list_del(&client->detected); | |
1943 | i2c_unregister_device(client); | |
bbd2d9c9 | 1944 | } |
dafc50d1 | 1945 | mutex_unlock(&adap->userspace_clients_lock); |
bbd2d9c9 | 1946 | |
e549c2b5 | 1947 | /* Detach any active clients. This can't fail, thus we do not |
5219bf88 JD |
1948 | * check the returned value. This is a two-pass process, because |
1949 | * we can't remove the dummy devices during the first pass: they | |
1950 | * could have been instantiated by real devices wishing to clean | |
1951 | * them up properly, so we give them a chance to do that first. */ | |
19baba4c LPC |
1952 | device_for_each_child(&adap->dev, NULL, __unregister_client); |
1953 | device_for_each_child(&adap->dev, NULL, __unregister_dummy); | |
1da177e4 | 1954 | |
2bb5095a JD |
1955 | #ifdef CONFIG_I2C_COMPAT |
1956 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
1957 | adap->dev.parent); | |
1958 | #endif | |
1959 | ||
c5567521 TLSC |
1960 | /* device name is gone after device_unregister */ |
1961 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); | |
1962 | ||
9f924169 WS |
1963 | pm_runtime_disable(&adap->dev); |
1964 | ||
26680ee2 WS |
1965 | /* wait until all references to the device are gone |
1966 | * | |
1967 | * FIXME: This is old code and should ideally be replaced by an | |
1968 | * alternative which results in decoupling the lifetime of the struct | |
1969 | * device from the i2c_adapter, like spi or netdev do. Any solution | |
95cc1e3d | 1970 | * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled! |
26680ee2 | 1971 | */ |
1da177e4 | 1972 | init_completion(&adap->dev_released); |
1da177e4 | 1973 | device_unregister(&adap->dev); |
1da177e4 | 1974 | wait_for_completion(&adap->dev_released); |
1da177e4 | 1975 | |
6e13e641 | 1976 | /* free bus id */ |
35fc37f8 | 1977 | mutex_lock(&core_lock); |
1da177e4 | 1978 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 1979 | mutex_unlock(&core_lock); |
1da177e4 | 1980 | |
bd4bc3db JD |
1981 | /* Clear the device structure in case this adapter is ever going to be |
1982 | added again */ | |
1983 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
1da177e4 | 1984 | } |
c0564606 | 1985 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 | 1986 | |
54177ccf WS |
1987 | /** |
1988 | * i2c_parse_fw_timings - get I2C related timing parameters from firmware | |
1989 | * @dev: The device to scan for I2C timing properties | |
1990 | * @t: the i2c_timings struct to be filled with values | |
1991 | * @use_defaults: bool to use sane defaults derived from the I2C specification | |
1992 | * when properties are not found, otherwise use 0 | |
1993 | * | |
1994 | * Scan the device for the generic I2C properties describing timing parameters | |
1995 | * for the signal and fill the given struct with the results. If a property was | |
1996 | * not found and use_defaults was true, then maximum timings are assumed which | |
1997 | * are derived from the I2C specification. If use_defaults is not used, the | |
1998 | * results will be 0, so drivers can apply their own defaults later. The latter | |
1999 | * is mainly intended for avoiding regressions of existing drivers which want | |
2000 | * to switch to this function. New drivers almost always should use the defaults. | |
2001 | */ | |
2002 | ||
2003 | void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults) | |
2004 | { | |
2005 | int ret; | |
2006 | ||
2007 | memset(t, 0, sizeof(*t)); | |
2008 | ||
2009 | ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz); | |
2010 | if (ret && use_defaults) | |
2011 | t->bus_freq_hz = 100000; | |
2012 | ||
2013 | ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns); | |
2014 | if (ret && use_defaults) { | |
2015 | if (t->bus_freq_hz <= 100000) | |
2016 | t->scl_rise_ns = 1000; | |
2017 | else if (t->bus_freq_hz <= 400000) | |
2018 | t->scl_rise_ns = 300; | |
2019 | else | |
2020 | t->scl_rise_ns = 120; | |
2021 | } | |
2022 | ||
2023 | ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns); | |
2024 | if (ret && use_defaults) { | |
2025 | if (t->bus_freq_hz <= 400000) | |
2026 | t->scl_fall_ns = 300; | |
2027 | else | |
2028 | t->scl_fall_ns = 120; | |
2029 | } | |
2030 | ||
2031 | device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns); | |
2032 | ||
2033 | ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns); | |
2034 | if (ret && use_defaults) | |
2035 | t->sda_fall_ns = t->scl_fall_ns; | |
2036 | } | |
2037 | EXPORT_SYMBOL_GPL(i2c_parse_fw_timings); | |
2038 | ||
7b4fbc50 DB |
2039 | /* ------------------------------------------------------------------------- */ |
2040 | ||
7ae31482 JD |
2041 | int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) |
2042 | { | |
2043 | int res; | |
2044 | ||
2045 | mutex_lock(&core_lock); | |
2046 | res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); | |
2047 | mutex_unlock(&core_lock); | |
2048 | ||
2049 | return res; | |
2050 | } | |
2051 | EXPORT_SYMBOL_GPL(i2c_for_each_dev); | |
2052 | ||
69b0089a | 2053 | static int __process_new_driver(struct device *dev, void *data) |
7f101a97 | 2054 | { |
4f8cf824 JD |
2055 | if (dev->type != &i2c_adapter_type) |
2056 | return 0; | |
69b0089a | 2057 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
7f101a97 DY |
2058 | } |
2059 | ||
7b4fbc50 DB |
2060 | /* |
2061 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 2062 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
2063 | */ |
2064 | ||
de59cf9e | 2065 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 2066 | { |
7eebcb7c | 2067 | int res; |
1da177e4 | 2068 | |
1d0b19c9 | 2069 | /* Can't register until after driver model init */ |
95026658 | 2070 | if (WARN_ON(!is_registered)) |
1d0b19c9 DB |
2071 | return -EAGAIN; |
2072 | ||
1da177e4 | 2073 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 2074 | driver->driver.owner = owner; |
1da177e4 | 2075 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 2076 | |
729d6dd5 | 2077 | /* When registration returns, the driver core |
6e13e641 DB |
2078 | * will have called probe() for all matching-but-unbound devices. |
2079 | */ | |
1da177e4 LT |
2080 | res = driver_register(&driver->driver); |
2081 | if (res) | |
7eebcb7c | 2082 | return res; |
438d6c2c | 2083 | |
44239a5a | 2084 | pr_debug("driver [%s] registered\n", driver->driver.name); |
1da177e4 | 2085 | |
4735c98f JD |
2086 | INIT_LIST_HEAD(&driver->clients); |
2087 | /* Walk the adapters that are already present */ | |
7ae31482 | 2088 | i2c_for_each_dev(driver, __process_new_driver); |
35fc37f8 | 2089 | |
7f101a97 DY |
2090 | return 0; |
2091 | } | |
2092 | EXPORT_SYMBOL(i2c_register_driver); | |
2093 | ||
69b0089a | 2094 | static int __process_removed_driver(struct device *dev, void *data) |
7f101a97 | 2095 | { |
19baba4c LPC |
2096 | if (dev->type == &i2c_adapter_type) |
2097 | i2c_do_del_adapter(data, to_i2c_adapter(dev)); | |
2098 | return 0; | |
1da177e4 LT |
2099 | } |
2100 | ||
a1d9e6e4 DB |
2101 | /** |
2102 | * i2c_del_driver - unregister I2C driver | |
2103 | * @driver: the driver being unregistered | |
d64f73be | 2104 | * Context: can sleep |
a1d9e6e4 | 2105 | */ |
b3e82096 | 2106 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 2107 | { |
7ae31482 | 2108 | i2c_for_each_dev(driver, __process_removed_driver); |
1da177e4 LT |
2109 | |
2110 | driver_unregister(&driver->driver); | |
44239a5a | 2111 | pr_debug("driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 2112 | } |
c0564606 | 2113 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 2114 | |
7b4fbc50 DB |
2115 | /* ------------------------------------------------------------------------- */ |
2116 | ||
e48d3319 JD |
2117 | /** |
2118 | * i2c_use_client - increments the reference count of the i2c client structure | |
2119 | * @client: the client being referenced | |
2120 | * | |
2121 | * Each live reference to a client should be refcounted. The driver model does | |
2122 | * that automatically as part of driver binding, so that most drivers don't | |
2123 | * need to do this explicitly: they hold a reference until they're unbound | |
2124 | * from the device. | |
2125 | * | |
2126 | * A pointer to the client with the incremented reference counter is returned. | |
2127 | */ | |
2128 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 2129 | { |
6ea438ec DB |
2130 | if (client && get_device(&client->dev)) |
2131 | return client; | |
2132 | return NULL; | |
1da177e4 | 2133 | } |
c0564606 | 2134 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 2135 | |
e48d3319 JD |
2136 | /** |
2137 | * i2c_release_client - release a use of the i2c client structure | |
2138 | * @client: the client being no longer referenced | |
2139 | * | |
2140 | * Must be called when a user of a client is finished with it. | |
2141 | */ | |
2142 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 2143 | { |
6ea438ec DB |
2144 | if (client) |
2145 | put_device(&client->dev); | |
1da177e4 | 2146 | } |
c0564606 | 2147 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 2148 | |
9b766b81 DB |
2149 | struct i2c_cmd_arg { |
2150 | unsigned cmd; | |
2151 | void *arg; | |
2152 | }; | |
2153 | ||
2154 | static int i2c_cmd(struct device *dev, void *_arg) | |
2155 | { | |
2156 | struct i2c_client *client = i2c_verify_client(dev); | |
2157 | struct i2c_cmd_arg *arg = _arg; | |
0acc2b32 LPC |
2158 | struct i2c_driver *driver; |
2159 | ||
2160 | if (!client || !client->dev.driver) | |
2161 | return 0; | |
9b766b81 | 2162 | |
0acc2b32 LPC |
2163 | driver = to_i2c_driver(client->dev.driver); |
2164 | if (driver->command) | |
2165 | driver->command(client, arg->cmd, arg->arg); | |
9b766b81 DB |
2166 | return 0; |
2167 | } | |
2168 | ||
1da177e4 LT |
2169 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
2170 | { | |
9b766b81 | 2171 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 2172 | |
9b766b81 DB |
2173 | cmd_arg.cmd = cmd; |
2174 | cmd_arg.arg = arg; | |
2175 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 2176 | } |
c0564606 | 2177 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 | 2178 | |
ea7513bb PA |
2179 | #if IS_ENABLED(CONFIG_OF_DYNAMIC) |
2180 | static int of_i2c_notify(struct notifier_block *nb, unsigned long action, | |
2181 | void *arg) | |
2182 | { | |
2183 | struct of_reconfig_data *rd = arg; | |
2184 | struct i2c_adapter *adap; | |
2185 | struct i2c_client *client; | |
2186 | ||
2187 | switch (of_reconfig_get_state_change(action, rd)) { | |
2188 | case OF_RECONFIG_CHANGE_ADD: | |
2189 | adap = of_find_i2c_adapter_by_node(rd->dn->parent); | |
2190 | if (adap == NULL) | |
2191 | return NOTIFY_OK; /* not for us */ | |
2192 | ||
4f001fd3 PA |
2193 | if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { |
2194 | put_device(&adap->dev); | |
2195 | return NOTIFY_OK; | |
2196 | } | |
2197 | ||
ea7513bb PA |
2198 | client = of_i2c_register_device(adap, rd->dn); |
2199 | put_device(&adap->dev); | |
2200 | ||
2201 | if (IS_ERR(client)) { | |
399d62ac WS |
2202 | dev_err(&adap->dev, "failed to create client for '%s'\n", |
2203 | rd->dn->full_name); | |
ea7513bb PA |
2204 | return notifier_from_errno(PTR_ERR(client)); |
2205 | } | |
2206 | break; | |
2207 | case OF_RECONFIG_CHANGE_REMOVE: | |
4f001fd3 PA |
2208 | /* already depopulated? */ |
2209 | if (!of_node_check_flag(rd->dn, OF_POPULATED)) | |
2210 | return NOTIFY_OK; | |
2211 | ||
ea7513bb PA |
2212 | /* find our device by node */ |
2213 | client = of_find_i2c_device_by_node(rd->dn); | |
2214 | if (client == NULL) | |
2215 | return NOTIFY_OK; /* no? not meant for us */ | |
2216 | ||
2217 | /* unregister takes one ref away */ | |
2218 | i2c_unregister_device(client); | |
2219 | ||
2220 | /* and put the reference of the find */ | |
2221 | put_device(&client->dev); | |
2222 | break; | |
2223 | } | |
2224 | ||
2225 | return NOTIFY_OK; | |
2226 | } | |
2227 | static struct notifier_block i2c_of_notifier = { | |
2228 | .notifier_call = of_i2c_notify, | |
2229 | }; | |
2230 | #else | |
2231 | extern struct notifier_block i2c_of_notifier; | |
2232 | #endif /* CONFIG_OF_DYNAMIC */ | |
2233 | ||
1da177e4 LT |
2234 | static int __init i2c_init(void) |
2235 | { | |
2236 | int retval; | |
2237 | ||
03bde7c3 WS |
2238 | retval = of_alias_get_highest_id("i2c"); |
2239 | ||
2240 | down_write(&__i2c_board_lock); | |
2241 | if (retval >= __i2c_first_dynamic_bus_num) | |
2242 | __i2c_first_dynamic_bus_num = retval + 1; | |
2243 | up_write(&__i2c_board_lock); | |
2244 | ||
1da177e4 | 2245 | retval = bus_register(&i2c_bus_type); |
1da177e4 LT |
2246 | if (retval) |
2247 | return retval; | |
b980a26d WS |
2248 | |
2249 | is_registered = true; | |
2250 | ||
2bb5095a JD |
2251 | #ifdef CONFIG_I2C_COMPAT |
2252 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
2253 | if (!i2c_adapter_compat_class) { | |
2254 | retval = -ENOMEM; | |
2255 | goto bus_err; | |
2256 | } | |
2257 | #endif | |
e9f1373b DB |
2258 | retval = i2c_add_driver(&dummy_driver); |
2259 | if (retval) | |
2bb5095a | 2260 | goto class_err; |
ea7513bb PA |
2261 | |
2262 | if (IS_ENABLED(CONFIG_OF_DYNAMIC)) | |
2263 | WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)); | |
525e6fab OP |
2264 | if (IS_ENABLED(CONFIG_ACPI)) |
2265 | WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier)); | |
ea7513bb | 2266 | |
e9f1373b DB |
2267 | return 0; |
2268 | ||
2bb5095a JD |
2269 | class_err: |
2270 | #ifdef CONFIG_I2C_COMPAT | |
2271 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 2272 | bus_err: |
2bb5095a | 2273 | #endif |
b980a26d | 2274 | is_registered = false; |
e9f1373b DB |
2275 | bus_unregister(&i2c_bus_type); |
2276 | return retval; | |
1da177e4 LT |
2277 | } |
2278 | ||
2279 | static void __exit i2c_exit(void) | |
2280 | { | |
525e6fab OP |
2281 | if (IS_ENABLED(CONFIG_ACPI)) |
2282 | WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier)); | |
ea7513bb PA |
2283 | if (IS_ENABLED(CONFIG_OF_DYNAMIC)) |
2284 | WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier)); | |
e9f1373b | 2285 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
2286 | #ifdef CONFIG_I2C_COMPAT |
2287 | class_compat_unregister(i2c_adapter_compat_class); | |
2288 | #endif | |
1da177e4 | 2289 | bus_unregister(&i2c_bus_type); |
d9a83d62 | 2290 | tracepoint_synchronize_unregister(); |
1da177e4 LT |
2291 | } |
2292 | ||
a10f9e7c DB |
2293 | /* We must initialize early, because some subsystems register i2c drivers |
2294 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
2295 | */ | |
2296 | postcore_initcall(i2c_init); | |
1da177e4 LT |
2297 | module_exit(i2c_exit); |
2298 | ||
2299 | /* ---------------------------------------------------- | |
2300 | * the functional interface to the i2c busses. | |
2301 | * ---------------------------------------------------- | |
2302 | */ | |
2303 | ||
b7f62584 WS |
2304 | /* Check if val is exceeding the quirk IFF quirk is non 0 */ |
2305 | #define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk))) | |
2306 | ||
2307 | static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg) | |
2308 | { | |
2309 | dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n", | |
2310 | err_msg, msg->addr, msg->len, | |
2311 | msg->flags & I2C_M_RD ? "read" : "write"); | |
2312 | return -EOPNOTSUPP; | |
2313 | } | |
2314 | ||
2315 | static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
2316 | { | |
2317 | const struct i2c_adapter_quirks *q = adap->quirks; | |
2318 | int max_num = q->max_num_msgs, i; | |
2319 | bool do_len_check = true; | |
2320 | ||
2321 | if (q->flags & I2C_AQ_COMB) { | |
2322 | max_num = 2; | |
2323 | ||
2324 | /* special checks for combined messages */ | |
2325 | if (num == 2) { | |
2326 | if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD) | |
2327 | return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write"); | |
2328 | ||
2329 | if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD)) | |
2330 | return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read"); | |
2331 | ||
2332 | if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr) | |
2333 | return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr"); | |
2334 | ||
2335 | if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len)) | |
2336 | return i2c_quirk_error(adap, &msgs[0], "msg too long"); | |
2337 | ||
2338 | if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len)) | |
2339 | return i2c_quirk_error(adap, &msgs[1], "msg too long"); | |
2340 | ||
2341 | do_len_check = false; | |
2342 | } | |
2343 | } | |
2344 | ||
2345 | if (i2c_quirk_exceeded(num, max_num)) | |
2346 | return i2c_quirk_error(adap, &msgs[0], "too many messages"); | |
2347 | ||
2348 | for (i = 0; i < num; i++) { | |
2349 | u16 len = msgs[i].len; | |
2350 | ||
2351 | if (msgs[i].flags & I2C_M_RD) { | |
2352 | if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len)) | |
2353 | return i2c_quirk_error(adap, &msgs[i], "msg too long"); | |
2354 | } else { | |
2355 | if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len)) | |
2356 | return i2c_quirk_error(adap, &msgs[i], "msg too long"); | |
2357 | } | |
2358 | } | |
2359 | ||
2360 | return 0; | |
2361 | } | |
2362 | ||
b37d2a3a JD |
2363 | /** |
2364 | * __i2c_transfer - unlocked flavor of i2c_transfer | |
2365 | * @adap: Handle to I2C bus | |
2366 | * @msgs: One or more messages to execute before STOP is issued to | |
2367 | * terminate the operation; each message begins with a START. | |
2368 | * @num: Number of messages to be executed. | |
2369 | * | |
2370 | * Returns negative errno, else the number of messages executed. | |
2371 | * | |
2372 | * Adapter lock must be held when calling this function. No debug logging | |
2373 | * takes place. adap->algo->master_xfer existence isn't checked. | |
2374 | */ | |
2375 | int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
2376 | { | |
2377 | unsigned long orig_jiffies; | |
2378 | int ret, try; | |
2379 | ||
b7f62584 WS |
2380 | if (adap->quirks && i2c_check_for_quirks(adap, msgs, num)) |
2381 | return -EOPNOTSUPP; | |
2382 | ||
d9a83d62 DH |
2383 | /* i2c_trace_msg gets enabled when tracepoint i2c_transfer gets |
2384 | * enabled. This is an efficient way of keeping the for-loop from | |
2385 | * being executed when not needed. | |
2386 | */ | |
2387 | if (static_key_false(&i2c_trace_msg)) { | |
2388 | int i; | |
2389 | for (i = 0; i < num; i++) | |
2390 | if (msgs[i].flags & I2C_M_RD) | |
2391 | trace_i2c_read(adap, &msgs[i], i); | |
2392 | else | |
2393 | trace_i2c_write(adap, &msgs[i], i); | |
2394 | } | |
2395 | ||
b37d2a3a JD |
2396 | /* Retry automatically on arbitration loss */ |
2397 | orig_jiffies = jiffies; | |
2398 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
2399 | ret = adap->algo->master_xfer(adap, msgs, num); | |
2400 | if (ret != -EAGAIN) | |
2401 | break; | |
2402 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
2403 | break; | |
2404 | } | |
2405 | ||
d9a83d62 DH |
2406 | if (static_key_false(&i2c_trace_msg)) { |
2407 | int i; | |
2408 | for (i = 0; i < ret; i++) | |
2409 | if (msgs[i].flags & I2C_M_RD) | |
2410 | trace_i2c_reply(adap, &msgs[i], i); | |
2411 | trace_i2c_result(adap, i, ret); | |
2412 | } | |
2413 | ||
b37d2a3a JD |
2414 | return ret; |
2415 | } | |
2416 | EXPORT_SYMBOL(__i2c_transfer); | |
2417 | ||
a1cdedac DB |
2418 | /** |
2419 | * i2c_transfer - execute a single or combined I2C message | |
2420 | * @adap: Handle to I2C bus | |
2421 | * @msgs: One or more messages to execute before STOP is issued to | |
2422 | * terminate the operation; each message begins with a START. | |
2423 | * @num: Number of messages to be executed. | |
2424 | * | |
2425 | * Returns negative errno, else the number of messages executed. | |
2426 | * | |
2427 | * Note that there is no requirement that each message be sent to | |
2428 | * the same slave address, although that is the most common model. | |
2429 | */ | |
09b8ce0a | 2430 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 2431 | { |
b37d2a3a | 2432 | int ret; |
1da177e4 | 2433 | |
a1cdedac DB |
2434 | /* REVISIT the fault reporting model here is weak: |
2435 | * | |
2436 | * - When we get an error after receiving N bytes from a slave, | |
2437 | * there is no way to report "N". | |
2438 | * | |
2439 | * - When we get a NAK after transmitting N bytes to a slave, | |
2440 | * there is no way to report "N" ... or to let the master | |
2441 | * continue executing the rest of this combined message, if | |
2442 | * that's the appropriate response. | |
2443 | * | |
2444 | * - When for example "num" is two and we successfully complete | |
2445 | * the first message but get an error part way through the | |
2446 | * second, it's unclear whether that should be reported as | |
2447 | * one (discarding status on the second message) or errno | |
2448 | * (discarding status on the first one). | |
2449 | */ | |
2450 | ||
1da177e4 LT |
2451 | if (adap->algo->master_xfer) { |
2452 | #ifdef DEBUG | |
2453 | for (ret = 0; ret < num; ret++) { | |
2454 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
2455 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
2456 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
2457 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
2458 | } |
2459 | #endif | |
2460 | ||
cea443a8 | 2461 | if (in_atomic() || irqs_disabled()) { |
8320f495 | 2462 | ret = adap->trylock_bus(adap, I2C_LOCK_SEGMENT); |
cea443a8 MR |
2463 | if (!ret) |
2464 | /* I2C activity is ongoing. */ | |
2465 | return -EAGAIN; | |
2466 | } else { | |
8320f495 | 2467 | i2c_lock_bus(adap, I2C_LOCK_SEGMENT); |
cea443a8 MR |
2468 | } |
2469 | ||
b37d2a3a | 2470 | ret = __i2c_transfer(adap, msgs, num); |
8320f495 | 2471 | i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); |
1da177e4 LT |
2472 | |
2473 | return ret; | |
2474 | } else { | |
2475 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 2476 | return -EOPNOTSUPP; |
1da177e4 LT |
2477 | } |
2478 | } | |
c0564606 | 2479 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 2480 | |
a1cdedac DB |
2481 | /** |
2482 | * i2c_master_send - issue a single I2C message in master transmit mode | |
2483 | * @client: Handle to slave device | |
2484 | * @buf: Data that will be written to the slave | |
0c43ea54 | 2485 | * @count: How many bytes to write, must be less than 64k since msg.len is u16 |
a1cdedac DB |
2486 | * |
2487 | * Returns negative errno, or else the number of bytes written. | |
2488 | */ | |
0cc43a18 | 2489 | int i2c_master_send(const struct i2c_client *client, const char *buf, int count) |
1da177e4 LT |
2490 | { |
2491 | int ret; | |
7225acf4 | 2492 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
2493 | struct i2c_msg msg; |
2494 | ||
815f55f2 JD |
2495 | msg.addr = client->addr; |
2496 | msg.flags = client->flags & I2C_M_TEN; | |
2497 | msg.len = count; | |
2498 | msg.buf = (char *)buf; | |
438d6c2c | 2499 | |
815f55f2 | 2500 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 2501 | |
834aa6f3 WS |
2502 | /* |
2503 | * If everything went ok (i.e. 1 msg transmitted), return #bytes | |
2504 | * transmitted, else error code. | |
2505 | */ | |
815f55f2 | 2506 | return (ret == 1) ? count : ret; |
1da177e4 | 2507 | } |
c0564606 | 2508 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 2509 | |
a1cdedac DB |
2510 | /** |
2511 | * i2c_master_recv - issue a single I2C message in master receive mode | |
2512 | * @client: Handle to slave device | |
2513 | * @buf: Where to store data read from slave | |
0c43ea54 | 2514 | * @count: How many bytes to read, must be less than 64k since msg.len is u16 |
a1cdedac DB |
2515 | * |
2516 | * Returns negative errno, or else the number of bytes read. | |
2517 | */ | |
0cc43a18 | 2518 | int i2c_master_recv(const struct i2c_client *client, char *buf, int count) |
1da177e4 | 2519 | { |
7225acf4 | 2520 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
2521 | struct i2c_msg msg; |
2522 | int ret; | |
815f55f2 JD |
2523 | |
2524 | msg.addr = client->addr; | |
2525 | msg.flags = client->flags & I2C_M_TEN; | |
2526 | msg.flags |= I2C_M_RD; | |
2527 | msg.len = count; | |
2528 | msg.buf = buf; | |
2529 | ||
2530 | ret = i2c_transfer(adap, &msg, 1); | |
2531 | ||
834aa6f3 WS |
2532 | /* |
2533 | * If everything went ok (i.e. 1 msg received), return #bytes received, | |
2534 | * else error code. | |
2535 | */ | |
815f55f2 | 2536 | return (ret == 1) ? count : ret; |
1da177e4 | 2537 | } |
c0564606 | 2538 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 2539 | |
1da177e4 LT |
2540 | /* ---------------------------------------------------- |
2541 | * the i2c address scanning function | |
2542 | * Will not work for 10-bit addresses! | |
2543 | * ---------------------------------------------------- | |
2544 | */ | |
1da177e4 | 2545 | |
63e4e802 JD |
2546 | /* |
2547 | * Legacy default probe function, mostly relevant for SMBus. The default | |
2548 | * probe method is a quick write, but it is known to corrupt the 24RF08 | |
2549 | * EEPROMs due to a state machine bug, and could also irreversibly | |
2550 | * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, | |
2551 | * we use a short byte read instead. Also, some bus drivers don't implement | |
2552 | * quick write, so we fallback to a byte read in that case too. | |
2553 | * On x86, there is another special case for FSC hardware monitoring chips, | |
2554 | * which want regular byte reads (address 0x73.) Fortunately, these are the | |
2555 | * only known chips using this I2C address on PC hardware. | |
2556 | * Returns 1 if probe succeeded, 0 if not. | |
2557 | */ | |
2558 | static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) | |
2559 | { | |
2560 | int err; | |
2561 | union i2c_smbus_data dummy; | |
2562 | ||
2563 | #ifdef CONFIG_X86 | |
2564 | if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) | |
2565 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) | |
2566 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
2567 | I2C_SMBUS_BYTE_DATA, &dummy); | |
2568 | else | |
2569 | #endif | |
8031d79b JD |
2570 | if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) |
2571 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) | |
63e4e802 JD |
2572 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, |
2573 | I2C_SMBUS_QUICK, NULL); | |
8031d79b JD |
2574 | else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) |
2575 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
2576 | I2C_SMBUS_BYTE, &dummy); | |
2577 | else { | |
d63a9e85 AL |
2578 | dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", |
2579 | addr); | |
8031d79b JD |
2580 | err = -EOPNOTSUPP; |
2581 | } | |
63e4e802 JD |
2582 | |
2583 | return err >= 0; | |
2584 | } | |
2585 | ||
ccfbbd08 | 2586 | static int i2c_detect_address(struct i2c_client *temp_client, |
4735c98f JD |
2587 | struct i2c_driver *driver) |
2588 | { | |
2589 | struct i2c_board_info info; | |
2590 | struct i2c_adapter *adapter = temp_client->adapter; | |
2591 | int addr = temp_client->addr; | |
2592 | int err; | |
2593 | ||
2594 | /* Make sure the address is valid */ | |
66be6056 | 2595 | err = i2c_check_7bit_addr_validity_strict(addr); |
656b8761 | 2596 | if (err) { |
4735c98f JD |
2597 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
2598 | addr); | |
656b8761 | 2599 | return err; |
4735c98f JD |
2600 | } |
2601 | ||
9bccc70a | 2602 | /* Skip if already in use (7 bit, no need to encode flags) */ |
3b5f794b | 2603 | if (i2c_check_addr_busy(adapter, addr)) |
4735c98f JD |
2604 | return 0; |
2605 | ||
ccfbbd08 | 2606 | /* Make sure there is something at this address */ |
63e4e802 JD |
2607 | if (!i2c_default_probe(adapter, addr)) |
2608 | return 0; | |
4735c98f JD |
2609 | |
2610 | /* Finally call the custom detection function */ | |
2611 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
2612 | info.addr = addr; | |
310ec792 | 2613 | err = driver->detect(temp_client, &info); |
4735c98f JD |
2614 | if (err) { |
2615 | /* -ENODEV is returned if the detection fails. We catch it | |
2616 | here as this isn't an error. */ | |
2617 | return err == -ENODEV ? 0 : err; | |
2618 | } | |
2619 | ||
2620 | /* Consistency check */ | |
2621 | if (info.type[0] == '\0') { | |
2622 | dev_err(&adapter->dev, "%s detection function provided " | |
2623 | "no name for 0x%x\n", driver->driver.name, | |
2624 | addr); | |
2625 | } else { | |
2626 | struct i2c_client *client; | |
2627 | ||
2628 | /* Detection succeeded, instantiate the device */ | |
0c176170 WS |
2629 | if (adapter->class & I2C_CLASS_DEPRECATED) |
2630 | dev_warn(&adapter->dev, | |
2631 | "This adapter will soon drop class based instantiation of devices. " | |
2632 | "Please make sure client 0x%02x gets instantiated by other means. " | |
2633 | "Check 'Documentation/i2c/instantiating-devices' for details.\n", | |
2634 | info.addr); | |
2635 | ||
4735c98f JD |
2636 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", |
2637 | info.type, info.addr); | |
2638 | client = i2c_new_device(adapter, &info); | |
2639 | if (client) | |
2640 | list_add_tail(&client->detected, &driver->clients); | |
2641 | else | |
2642 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
2643 | info.type, info.addr); | |
2644 | } | |
2645 | return 0; | |
2646 | } | |
2647 | ||
2648 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
2649 | { | |
c3813d6a | 2650 | const unsigned short *address_list; |
4735c98f JD |
2651 | struct i2c_client *temp_client; |
2652 | int i, err = 0; | |
2653 | int adap_id = i2c_adapter_id(adapter); | |
2654 | ||
c3813d6a JD |
2655 | address_list = driver->address_list; |
2656 | if (!driver->detect || !address_list) | |
4735c98f JD |
2657 | return 0; |
2658 | ||
45552272 WS |
2659 | /* Warn that the adapter lost class based instantiation */ |
2660 | if (adapter->class == I2C_CLASS_DEPRECATED) { | |
2661 | dev_dbg(&adapter->dev, | |
2662 | "This adapter dropped support for I2C classes and " | |
2663 | "won't auto-detect %s devices anymore. If you need it, check " | |
2664 | "'Documentation/i2c/instantiating-devices' for alternatives.\n", | |
2665 | driver->driver.name); | |
2666 | return 0; | |
2667 | } | |
2668 | ||
51b54ba9 JD |
2669 | /* Stop here if the classes do not match */ |
2670 | if (!(adapter->class & driver->class)) | |
2671 | return 0; | |
2672 | ||
4735c98f JD |
2673 | /* Set up a temporary client to help detect callback */ |
2674 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
2675 | if (!temp_client) | |
2676 | return -ENOMEM; | |
2677 | temp_client->adapter = adapter; | |
2678 | ||
c3813d6a | 2679 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
4735c98f | 2680 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
c3813d6a JD |
2681 | "addr 0x%02x\n", adap_id, address_list[i]); |
2682 | temp_client->addr = address_list[i]; | |
ccfbbd08 | 2683 | err = i2c_detect_address(temp_client, driver); |
51b54ba9 JD |
2684 | if (unlikely(err)) |
2685 | break; | |
4735c98f JD |
2686 | } |
2687 | ||
4735c98f JD |
2688 | kfree(temp_client); |
2689 | return err; | |
2690 | } | |
2691 | ||
d44f19d5 JD |
2692 | int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) |
2693 | { | |
2694 | return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
2695 | I2C_SMBUS_QUICK, NULL) >= 0; | |
2696 | } | |
2697 | EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); | |
2698 | ||
12b5053a JD |
2699 | struct i2c_client * |
2700 | i2c_new_probed_device(struct i2c_adapter *adap, | |
2701 | struct i2c_board_info *info, | |
9a94241a JD |
2702 | unsigned short const *addr_list, |
2703 | int (*probe)(struct i2c_adapter *, unsigned short addr)) | |
12b5053a JD |
2704 | { |
2705 | int i; | |
2706 | ||
8031d79b | 2707 | if (!probe) |
9a94241a | 2708 | probe = i2c_default_probe; |
12b5053a | 2709 | |
12b5053a JD |
2710 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
2711 | /* Check address validity */ | |
66be6056 | 2712 | if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) { |
12b5053a JD |
2713 | dev_warn(&adap->dev, "Invalid 7-bit address " |
2714 | "0x%02x\n", addr_list[i]); | |
2715 | continue; | |
2716 | } | |
2717 | ||
9bccc70a | 2718 | /* Check address availability (7 bit, no need to encode flags) */ |
3b5f794b | 2719 | if (i2c_check_addr_busy(adap, addr_list[i])) { |
12b5053a JD |
2720 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
2721 | "use, not probing\n", addr_list[i]); | |
2722 | continue; | |
2723 | } | |
2724 | ||
63e4e802 | 2725 | /* Test address responsiveness */ |
9a94241a | 2726 | if (probe(adap, addr_list[i])) |
63e4e802 | 2727 | break; |
12b5053a | 2728 | } |
12b5053a JD |
2729 | |
2730 | if (addr_list[i] == I2C_CLIENT_END) { | |
2731 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
2732 | return NULL; | |
2733 | } | |
2734 | ||
2735 | info->addr = addr_list[i]; | |
2736 | return i2c_new_device(adap, info); | |
2737 | } | |
2738 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
2739 | ||
d735b34d | 2740 | struct i2c_adapter *i2c_get_adapter(int nr) |
1da177e4 | 2741 | { |
1da177e4 | 2742 | struct i2c_adapter *adapter; |
438d6c2c | 2743 | |
caada32a | 2744 | mutex_lock(&core_lock); |
d735b34d | 2745 | adapter = idr_find(&i2c_adapter_idr, nr); |
611e12ea VZ |
2746 | if (!adapter) |
2747 | goto exit; | |
2748 | ||
2749 | if (try_module_get(adapter->owner)) | |
2750 | get_device(&adapter->dev); | |
2751 | else | |
a0920e10 MH |
2752 | adapter = NULL; |
2753 | ||
611e12ea | 2754 | exit: |
caada32a | 2755 | mutex_unlock(&core_lock); |
a0920e10 | 2756 | return adapter; |
1da177e4 | 2757 | } |
c0564606 | 2758 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
2759 | |
2760 | void i2c_put_adapter(struct i2c_adapter *adap) | |
2761 | { | |
611e12ea VZ |
2762 | if (!adap) |
2763 | return; | |
2764 | ||
2765 | put_device(&adap->dev); | |
2766 | module_put(adap->owner); | |
1da177e4 | 2767 | } |
c0564606 | 2768 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
2769 | |
2770 | /* The SMBus parts */ | |
2771 | ||
438d6c2c | 2772 | #define POLY (0x1070U << 3) |
09b8ce0a | 2773 | static u8 crc8(u16 data) |
1da177e4 LT |
2774 | { |
2775 | int i; | |
438d6c2c | 2776 | |
7225acf4 | 2777 | for (i = 0; i < 8; i++) { |
438d6c2c | 2778 | if (data & 0x8000) |
1da177e4 LT |
2779 | data = data ^ POLY; |
2780 | data = data << 1; | |
2781 | } | |
2782 | return (u8)(data >> 8); | |
2783 | } | |
2784 | ||
421ef47b JD |
2785 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
2786 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
2787 | { |
2788 | int i; | |
2789 | ||
7225acf4 | 2790 | for (i = 0; i < count; i++) |
421ef47b | 2791 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
2792 | return crc; |
2793 | } | |
2794 | ||
421ef47b JD |
2795 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
2796 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 2797 | { |
421ef47b | 2798 | /* The address will be sent first */ |
041edda8 | 2799 | u8 addr = i2c_8bit_addr_from_msg(msg); |
421ef47b JD |
2800 | pec = i2c_smbus_pec(pec, &addr, 1); |
2801 | ||
2802 | /* The data buffer follows */ | |
2803 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
2804 | } |
2805 | ||
421ef47b JD |
2806 | /* Used for write only transactions */ |
2807 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 2808 | { |
421ef47b JD |
2809 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
2810 | msg->len++; | |
1da177e4 LT |
2811 | } |
2812 | ||
421ef47b JD |
2813 | /* Return <0 on CRC error |
2814 | If there was a write before this read (most cases) we need to take the | |
2815 | partial CRC from the write part into account. | |
2816 | Note that this function does modify the message (we need to decrease the | |
2817 | message length to hide the CRC byte from the caller). */ | |
2818 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 2819 | { |
421ef47b JD |
2820 | u8 rpec = msg->buf[--msg->len]; |
2821 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 2822 | |
1da177e4 | 2823 | if (rpec != cpec) { |
44239a5a | 2824 | pr_debug("Bad PEC 0x%02x vs. 0x%02x\n", |
1da177e4 | 2825 | rpec, cpec); |
24a5bb7b | 2826 | return -EBADMSG; |
1da177e4 | 2827 | } |
438d6c2c | 2828 | return 0; |
1da177e4 LT |
2829 | } |
2830 | ||
a1cdedac DB |
2831 | /** |
2832 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
2833 | * @client: Handle to slave device | |
2834 | * | |
2835 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
2836 | * else the byte received from the device. | |
2837 | */ | |
0cc43a18 | 2838 | s32 i2c_smbus_read_byte(const struct i2c_client *client) |
1da177e4 LT |
2839 | { |
2840 | union i2c_smbus_data data; | |
24a5bb7b DB |
2841 | int status; |
2842 | ||
2843 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2844 | I2C_SMBUS_READ, 0, | |
2845 | I2C_SMBUS_BYTE, &data); | |
2846 | return (status < 0) ? status : data.byte; | |
1da177e4 | 2847 | } |
c0564606 | 2848 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 2849 | |
a1cdedac DB |
2850 | /** |
2851 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
2852 | * @client: Handle to slave device | |
2853 | * @value: Byte to be sent | |
2854 | * | |
2855 | * This executes the SMBus "send byte" protocol, returning negative errno | |
2856 | * else zero on success. | |
2857 | */ | |
0cc43a18 | 2858 | s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value) |
1da177e4 | 2859 | { |
7225acf4 | 2860 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
421ef47b | 2861 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 2862 | } |
c0564606 | 2863 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 2864 | |
a1cdedac DB |
2865 | /** |
2866 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
2867 | * @client: Handle to slave device | |
2868 | * @command: Byte interpreted by slave | |
2869 | * | |
2870 | * This executes the SMBus "read byte" protocol, returning negative errno | |
2871 | * else a data byte received from the device. | |
2872 | */ | |
0cc43a18 | 2873 | s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command) |
1da177e4 LT |
2874 | { |
2875 | union i2c_smbus_data data; | |
24a5bb7b DB |
2876 | int status; |
2877 | ||
2878 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2879 | I2C_SMBUS_READ, command, | |
2880 | I2C_SMBUS_BYTE_DATA, &data); | |
2881 | return (status < 0) ? status : data.byte; | |
1da177e4 | 2882 | } |
c0564606 | 2883 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 2884 | |
a1cdedac DB |
2885 | /** |
2886 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
2887 | * @client: Handle to slave device | |
2888 | * @command: Byte interpreted by slave | |
2889 | * @value: Byte being written | |
2890 | * | |
2891 | * This executes the SMBus "write byte" protocol, returning negative errno | |
2892 | * else zero on success. | |
2893 | */ | |
0cc43a18 JD |
2894 | s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command, |
2895 | u8 value) | |
1da177e4 LT |
2896 | { |
2897 | union i2c_smbus_data data; | |
2898 | data.byte = value; | |
7225acf4 FH |
2899 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2900 | I2C_SMBUS_WRITE, command, | |
2901 | I2C_SMBUS_BYTE_DATA, &data); | |
1da177e4 | 2902 | } |
c0564606 | 2903 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 2904 | |
a1cdedac DB |
2905 | /** |
2906 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
2907 | * @client: Handle to slave device | |
2908 | * @command: Byte interpreted by slave | |
2909 | * | |
2910 | * This executes the SMBus "read word" protocol, returning negative errno | |
2911 | * else a 16-bit unsigned "word" received from the device. | |
2912 | */ | |
0cc43a18 | 2913 | s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command) |
1da177e4 LT |
2914 | { |
2915 | union i2c_smbus_data data; | |
24a5bb7b DB |
2916 | int status; |
2917 | ||
2918 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2919 | I2C_SMBUS_READ, command, | |
2920 | I2C_SMBUS_WORD_DATA, &data); | |
2921 | return (status < 0) ? status : data.word; | |
1da177e4 | 2922 | } |
c0564606 | 2923 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 2924 | |
a1cdedac DB |
2925 | /** |
2926 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
2927 | * @client: Handle to slave device | |
2928 | * @command: Byte interpreted by slave | |
2929 | * @value: 16-bit "word" being written | |
2930 | * | |
2931 | * This executes the SMBus "write word" protocol, returning negative errno | |
2932 | * else zero on success. | |
2933 | */ | |
0cc43a18 JD |
2934 | s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command, |
2935 | u16 value) | |
1da177e4 LT |
2936 | { |
2937 | union i2c_smbus_data data; | |
2938 | data.word = value; | |
7225acf4 FH |
2939 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2940 | I2C_SMBUS_WRITE, command, | |
2941 | I2C_SMBUS_WORD_DATA, &data); | |
1da177e4 | 2942 | } |
c0564606 | 2943 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 2944 | |
a64ec07d | 2945 | /** |
a1cdedac | 2946 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 2947 | * @client: Handle to slave device |
a1cdedac | 2948 | * @command: Byte interpreted by slave |
a64ec07d DB |
2949 | * @values: Byte array into which data will be read; big enough to hold |
2950 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
2951 | * | |
a1cdedac DB |
2952 | * This executes the SMBus "block read" protocol, returning negative errno |
2953 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
2954 | * |
2955 | * Note that using this function requires that the client's adapter support | |
2956 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
2957 | * support this; its emulation through I2C messaging relies on a specific | |
2958 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
2959 | */ | |
0cc43a18 | 2960 | s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command, |
b86a1bc8 JD |
2961 | u8 *values) |
2962 | { | |
2963 | union i2c_smbus_data data; | |
24a5bb7b | 2964 | int status; |
b86a1bc8 | 2965 | |
24a5bb7b DB |
2966 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2967 | I2C_SMBUS_READ, command, | |
2968 | I2C_SMBUS_BLOCK_DATA, &data); | |
2969 | if (status) | |
2970 | return status; | |
b86a1bc8 JD |
2971 | |
2972 | memcpy(values, &data.block[1], data.block[0]); | |
2973 | return data.block[0]; | |
2974 | } | |
2975 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
2976 | ||
a1cdedac DB |
2977 | /** |
2978 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
2979 | * @client: Handle to slave device | |
2980 | * @command: Byte interpreted by slave | |
2981 | * @length: Size of data block; SMBus allows at most 32 bytes | |
2982 | * @values: Byte array which will be written. | |
2983 | * | |
2984 | * This executes the SMBus "block write" protocol, returning negative errno | |
2985 | * else zero on success. | |
2986 | */ | |
0cc43a18 | 2987 | s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command, |
46f5ed75 | 2988 | u8 length, const u8 *values) |
1da177e4 LT |
2989 | { |
2990 | union i2c_smbus_data data; | |
7656032b | 2991 | |
1da177e4 LT |
2992 | if (length > I2C_SMBUS_BLOCK_MAX) |
2993 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 2994 | data.block[0] = length; |
7656032b | 2995 | memcpy(&data.block[1], values, length); |
7225acf4 FH |
2996 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2997 | I2C_SMBUS_WRITE, command, | |
2998 | I2C_SMBUS_BLOCK_DATA, &data); | |
1da177e4 | 2999 | } |
c0564606 | 3000 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
3001 | |
3002 | /* Returns the number of read bytes */ | |
0cc43a18 | 3003 | s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command, |
4b2643d7 | 3004 | u8 length, u8 *values) |
1da177e4 LT |
3005 | { |
3006 | union i2c_smbus_data data; | |
24a5bb7b | 3007 | int status; |
7656032b | 3008 | |
4b2643d7 JD |
3009 | if (length > I2C_SMBUS_BLOCK_MAX) |
3010 | length = I2C_SMBUS_BLOCK_MAX; | |
3011 | data.block[0] = length; | |
24a5bb7b DB |
3012 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
3013 | I2C_SMBUS_READ, command, | |
3014 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
3015 | if (status < 0) | |
3016 | return status; | |
7656032b JD |
3017 | |
3018 | memcpy(values, &data.block[1], data.block[0]); | |
3019 | return data.block[0]; | |
1da177e4 | 3020 | } |
c0564606 | 3021 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 3022 | |
0cc43a18 | 3023 | s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command, |
46f5ed75 | 3024 | u8 length, const u8 *values) |
21bbd691 JD |
3025 | { |
3026 | union i2c_smbus_data data; | |
3027 | ||
3028 | if (length > I2C_SMBUS_BLOCK_MAX) | |
3029 | length = I2C_SMBUS_BLOCK_MAX; | |
3030 | data.block[0] = length; | |
3031 | memcpy(data.block + 1, values, length); | |
3032 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
3033 | I2C_SMBUS_WRITE, command, | |
3034 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
3035 | } | |
c0564606 | 3036 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 3037 | |
438d6c2c | 3038 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 3039 | No checking of parameters is done! */ |
7225acf4 FH |
3040 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, |
3041 | unsigned short flags, | |
3042 | char read_write, u8 command, int size, | |
3043 | union i2c_smbus_data *data) | |
1da177e4 LT |
3044 | { |
3045 | /* So we need to generate a series of msgs. In the case of writing, we | |
3046 | need to use only one message; when reading, we need two. We initialize | |
3047 | most things with sane defaults, to keep the code below somewhat | |
3048 | simpler. */ | |
5c50d188 HI |
3049 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
3050 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
7225acf4 | 3051 | int num = read_write == I2C_SMBUS_READ ? 2 : 1; |
1da177e4 | 3052 | int i; |
421ef47b | 3053 | u8 partial_pec = 0; |
24a5bb7b | 3054 | int status; |
230da094 S |
3055 | struct i2c_msg msg[2] = { |
3056 | { | |
3057 | .addr = addr, | |
3058 | .flags = flags, | |
3059 | .len = 1, | |
3060 | .buf = msgbuf0, | |
3061 | }, { | |
3062 | .addr = addr, | |
3063 | .flags = flags | I2C_M_RD, | |
3064 | .len = 0, | |
3065 | .buf = msgbuf1, | |
3066 | }, | |
3067 | }; | |
1da177e4 LT |
3068 | |
3069 | msgbuf0[0] = command; | |
7225acf4 | 3070 | switch (size) { |
1da177e4 LT |
3071 | case I2C_SMBUS_QUICK: |
3072 | msg[0].len = 0; | |
3073 | /* Special case: The read/write field is used as data */ | |
f29d2e02 RK |
3074 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
3075 | I2C_M_RD : 0); | |
1da177e4 LT |
3076 | num = 1; |
3077 | break; | |
3078 | case I2C_SMBUS_BYTE: | |
3079 | if (read_write == I2C_SMBUS_READ) { | |
3080 | /* Special case: only a read! */ | |
3081 | msg[0].flags = I2C_M_RD | flags; | |
3082 | num = 1; | |
3083 | } | |
3084 | break; | |
3085 | case I2C_SMBUS_BYTE_DATA: | |
3086 | if (read_write == I2C_SMBUS_READ) | |
3087 | msg[1].len = 1; | |
3088 | else { | |
3089 | msg[0].len = 2; | |
3090 | msgbuf0[1] = data->byte; | |
3091 | } | |
3092 | break; | |
3093 | case I2C_SMBUS_WORD_DATA: | |
3094 | if (read_write == I2C_SMBUS_READ) | |
3095 | msg[1].len = 2; | |
3096 | else { | |
7225acf4 | 3097 | msg[0].len = 3; |
1da177e4 | 3098 | msgbuf0[1] = data->word & 0xff; |
7eff82c8 | 3099 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
3100 | } |
3101 | break; | |
3102 | case I2C_SMBUS_PROC_CALL: | |
3103 | num = 2; /* Special case */ | |
3104 | read_write = I2C_SMBUS_READ; | |
3105 | msg[0].len = 3; | |
3106 | msg[1].len = 2; | |
3107 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 3108 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
3109 | break; |
3110 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 3111 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
3112 | msg[1].flags |= I2C_M_RECV_LEN; |
3113 | msg[1].len = 1; /* block length will be added by | |
3114 | the underlying bus driver */ | |
1da177e4 LT |
3115 | } else { |
3116 | msg[0].len = data->block[0] + 2; | |
3117 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
3118 | dev_err(&adapter->dev, |
3119 | "Invalid block write size %d\n", | |
3120 | data->block[0]); | |
3121 | return -EINVAL; | |
1da177e4 | 3122 | } |
5c50d188 | 3123 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
3124 | msgbuf0[i] = data->block[i-1]; |
3125 | } | |
3126 | break; | |
3127 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
3128 | num = 2; /* Another special case */ |
3129 | read_write = I2C_SMBUS_READ; | |
3130 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
3131 | dev_err(&adapter->dev, |
3132 | "Invalid block write size %d\n", | |
209d27c3 | 3133 | data->block[0]); |
24a5bb7b | 3134 | return -EINVAL; |
209d27c3 JD |
3135 | } |
3136 | msg[0].len = data->block[0] + 2; | |
3137 | for (i = 1; i < msg[0].len; i++) | |
3138 | msgbuf0[i] = data->block[i-1]; | |
3139 | msg[1].flags |= I2C_M_RECV_LEN; | |
3140 | msg[1].len = 1; /* block length will be added by | |
3141 | the underlying bus driver */ | |
3142 | break; | |
1da177e4 LT |
3143 | case I2C_SMBUS_I2C_BLOCK_DATA: |
3144 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 3145 | msg[1].len = data->block[0]; |
1da177e4 LT |
3146 | } else { |
3147 | msg[0].len = data->block[0] + 1; | |
30dac746 | 3148 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
3149 | dev_err(&adapter->dev, |
3150 | "Invalid block write size %d\n", | |
3151 | data->block[0]); | |
3152 | return -EINVAL; | |
1da177e4 LT |
3153 | } |
3154 | for (i = 1; i <= data->block[0]; i++) | |
3155 | msgbuf0[i] = data->block[i]; | |
3156 | } | |
3157 | break; | |
3158 | default: | |
24a5bb7b DB |
3159 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
3160 | return -EOPNOTSUPP; | |
1da177e4 LT |
3161 | } |
3162 | ||
421ef47b JD |
3163 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
3164 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
3165 | if (i) { | |
3166 | /* Compute PEC if first message is a write */ | |
3167 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 3168 | if (num == 1) /* Write only */ |
421ef47b JD |
3169 | i2c_smbus_add_pec(&msg[0]); |
3170 | else /* Write followed by read */ | |
3171 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
3172 | } | |
3173 | /* Ask for PEC if last message is a read */ | |
3174 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 3175 | msg[num-1].len++; |
421ef47b JD |
3176 | } |
3177 | ||
24a5bb7b DB |
3178 | status = i2c_transfer(adapter, msg, num); |
3179 | if (status < 0) | |
3180 | return status; | |
1da177e4 | 3181 | |
421ef47b JD |
3182 | /* Check PEC if last message is a read */ |
3183 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
3184 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
3185 | if (status < 0) | |
3186 | return status; | |
421ef47b JD |
3187 | } |
3188 | ||
1da177e4 | 3189 | if (read_write == I2C_SMBUS_READ) |
7225acf4 FH |
3190 | switch (size) { |
3191 | case I2C_SMBUS_BYTE: | |
3192 | data->byte = msgbuf0[0]; | |
3193 | break; | |
3194 | case I2C_SMBUS_BYTE_DATA: | |
3195 | data->byte = msgbuf1[0]; | |
3196 | break; | |
3197 | case I2C_SMBUS_WORD_DATA: | |
3198 | case I2C_SMBUS_PROC_CALL: | |
3199 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
3200 | break; | |
3201 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
3202 | for (i = 0; i < data->block[0]; i++) | |
3203 | data->block[i+1] = msgbuf1[i]; | |
3204 | break; | |
3205 | case I2C_SMBUS_BLOCK_DATA: | |
3206 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
3207 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
3208 | data->block[i] = msgbuf1[i]; | |
3209 | break; | |
1da177e4 LT |
3210 | } |
3211 | return 0; | |
3212 | } | |
3213 | ||
a1cdedac DB |
3214 | /** |
3215 | * i2c_smbus_xfer - execute SMBus protocol operations | |
3216 | * @adapter: Handle to I2C bus | |
3217 | * @addr: Address of SMBus slave on that bus | |
3218 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
3219 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
3220 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
3221 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
3222 | * @data: Data to be read or written | |
3223 | * | |
3224 | * This executes an SMBus protocol operation, and returns a negative | |
3225 | * errno code else zero on success. | |
3226 | */ | |
09b8ce0a | 3227 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
a1cdedac | 3228 | char read_write, u8 command, int protocol, |
09b8ce0a | 3229 | union i2c_smbus_data *data) |
1da177e4 | 3230 | { |
66b650f0 CW |
3231 | unsigned long orig_jiffies; |
3232 | int try; | |
1da177e4 | 3233 | s32 res; |
1da177e4 | 3234 | |
8a325997 DH |
3235 | /* If enabled, the following two tracepoints are conditional on |
3236 | * read_write and protocol. | |
3237 | */ | |
3238 | trace_smbus_write(adapter, addr, flags, read_write, | |
3239 | command, protocol, data); | |
3240 | trace_smbus_read(adapter, addr, flags, read_write, | |
3241 | command, protocol); | |
3242 | ||
d47726c5 | 3243 | flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB; |
1da177e4 LT |
3244 | |
3245 | if (adapter->algo->smbus_xfer) { | |
8320f495 | 3246 | i2c_lock_bus(adapter, I2C_LOCK_SEGMENT); |
66b650f0 CW |
3247 | |
3248 | /* Retry automatically on arbitration loss */ | |
3249 | orig_jiffies = jiffies; | |
3250 | for (res = 0, try = 0; try <= adapter->retries; try++) { | |
3251 | res = adapter->algo->smbus_xfer(adapter, addr, flags, | |
3252 | read_write, command, | |
3253 | protocol, data); | |
3254 | if (res != -EAGAIN) | |
3255 | break; | |
3256 | if (time_after(jiffies, | |
3257 | orig_jiffies + adapter->timeout)) | |
3258 | break; | |
3259 | } | |
8320f495 | 3260 | i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT); |
1da177e4 | 3261 | |
72fc2c7f | 3262 | if (res != -EOPNOTSUPP || !adapter->algo->master_xfer) |
8a325997 | 3263 | goto trace; |
72fc2c7f LP |
3264 | /* |
3265 | * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't | |
3266 | * implement native support for the SMBus operation. | |
3267 | */ | |
3268 | } | |
3269 | ||
8a325997 DH |
3270 | res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, |
3271 | command, protocol, data); | |
3272 | ||
3273 | trace: | |
3274 | /* If enabled, the reply tracepoint is conditional on read_write. */ | |
3275 | trace_smbus_reply(adapter, addr, flags, read_write, | |
3276 | command, protocol, data); | |
3277 | trace_smbus_result(adapter, addr, flags, read_write, | |
3278 | command, protocol, res); | |
3279 | ||
3280 | return res; | |
1da177e4 | 3281 | } |
1da177e4 | 3282 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 | 3283 | |
01eef96e IT |
3284 | /** |
3285 | * i2c_smbus_read_i2c_block_data_or_emulated - read block or emulate | |
3286 | * @client: Handle to slave device | |
3287 | * @command: Byte interpreted by slave | |
3288 | * @length: Size of data block; SMBus allows at most I2C_SMBUS_BLOCK_MAX bytes | |
3289 | * @values: Byte array into which data will be read; big enough to hold | |
3290 | * the data returned by the slave. SMBus allows at most | |
3291 | * I2C_SMBUS_BLOCK_MAX bytes. | |
3292 | * | |
3293 | * This executes the SMBus "block read" protocol if supported by the adapter. | |
3294 | * If block read is not supported, it emulates it using either word or byte | |
3295 | * read protocols depending on availability. | |
3296 | * | |
3297 | * The addresses of the I2C slave device that are accessed with this function | |
3298 | * must be mapped to a linear region, so that a block read will have the same | |
3299 | * effect as a byte read. Before using this function you must double-check | |
3300 | * if the I2C slave does support exchanging a block transfer with a byte | |
3301 | * transfer. | |
3302 | */ | |
3303 | s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, | |
3304 | u8 command, u8 length, u8 *values) | |
3305 | { | |
3306 | u8 i = 0; | |
3307 | int status; | |
3308 | ||
3309 | if (length > I2C_SMBUS_BLOCK_MAX) | |
3310 | length = I2C_SMBUS_BLOCK_MAX; | |
3311 | ||
3312 | if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) | |
3313 | return i2c_smbus_read_i2c_block_data(client, command, length, values); | |
3314 | ||
3315 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) | |
3316 | return -EOPNOTSUPP; | |
3317 | ||
3318 | if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)) { | |
3319 | while ((i + 2) <= length) { | |
3320 | status = i2c_smbus_read_word_data(client, command + i); | |
3321 | if (status < 0) | |
3322 | return status; | |
3323 | values[i] = status & 0xff; | |
3324 | values[i + 1] = status >> 8; | |
3325 | i += 2; | |
3326 | } | |
3327 | } | |
3328 | ||
3329 | while (i < length) { | |
3330 | status = i2c_smbus_read_byte_data(client, command + i); | |
3331 | if (status < 0) | |
3332 | return status; | |
3333 | values[i] = status; | |
3334 | i++; | |
3335 | } | |
3336 | ||
3337 | return i; | |
3338 | } | |
3339 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data_or_emulated); | |
3340 | ||
d5fd120e | 3341 | #if IS_ENABLED(CONFIG_I2C_SLAVE) |
4b1acc43 WS |
3342 | int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb) |
3343 | { | |
3344 | int ret; | |
3345 | ||
0c7cab96 WS |
3346 | if (!client || !slave_cb) { |
3347 | WARN(1, "insufficent data\n"); | |
4b1acc43 | 3348 | return -EINVAL; |
0c7cab96 | 3349 | } |
4b1acc43 | 3350 | |
c6909d6f WS |
3351 | if (!(client->flags & I2C_CLIENT_SLAVE)) |
3352 | dev_warn(&client->dev, "%s: client slave flag not set. You might see address collisions\n", | |
3353 | __func__); | |
3354 | ||
4b1acc43 WS |
3355 | if (!(client->flags & I2C_CLIENT_TEN)) { |
3356 | /* Enforce stricter address checking */ | |
66be6056 | 3357 | ret = i2c_check_7bit_addr_validity_strict(client->addr); |
0c7cab96 WS |
3358 | if (ret) { |
3359 | dev_err(&client->dev, "%s: invalid address\n", __func__); | |
4b1acc43 | 3360 | return ret; |
0c7cab96 | 3361 | } |
4b1acc43 WS |
3362 | } |
3363 | ||
0c7cab96 WS |
3364 | if (!client->adapter->algo->reg_slave) { |
3365 | dev_err(&client->dev, "%s: not supported by adapter\n", __func__); | |
4b1acc43 | 3366 | return -EOPNOTSUPP; |
0c7cab96 | 3367 | } |
4b1acc43 WS |
3368 | |
3369 | client->slave_cb = slave_cb; | |
3370 | ||
3371 | i2c_lock_adapter(client->adapter); | |
3372 | ret = client->adapter->algo->reg_slave(client); | |
3373 | i2c_unlock_adapter(client->adapter); | |
3374 | ||
0c7cab96 | 3375 | if (ret) { |
4b1acc43 | 3376 | client->slave_cb = NULL; |
0c7cab96 WS |
3377 | dev_err(&client->dev, "%s: adapter returned error %d\n", __func__, ret); |
3378 | } | |
4b1acc43 WS |
3379 | |
3380 | return ret; | |
3381 | } | |
3382 | EXPORT_SYMBOL_GPL(i2c_slave_register); | |
3383 | ||
3384 | int i2c_slave_unregister(struct i2c_client *client) | |
3385 | { | |
3386 | int ret; | |
3387 | ||
0c7cab96 WS |
3388 | if (!client->adapter->algo->unreg_slave) { |
3389 | dev_err(&client->dev, "%s: not supported by adapter\n", __func__); | |
4b1acc43 | 3390 | return -EOPNOTSUPP; |
0c7cab96 | 3391 | } |
4b1acc43 WS |
3392 | |
3393 | i2c_lock_adapter(client->adapter); | |
3394 | ret = client->adapter->algo->unreg_slave(client); | |
3395 | i2c_unlock_adapter(client->adapter); | |
3396 | ||
3397 | if (ret == 0) | |
3398 | client->slave_cb = NULL; | |
0c7cab96 WS |
3399 | else |
3400 | dev_err(&client->dev, "%s: adapter returned error %d\n", __func__, ret); | |
4b1acc43 WS |
3401 | |
3402 | return ret; | |
3403 | } | |
3404 | EXPORT_SYMBOL_GPL(i2c_slave_unregister); | |
d5fd120e | 3405 | #endif |
4b1acc43 | 3406 | |
1da177e4 LT |
3407 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); |
3408 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
3409 | MODULE_LICENSE("GPL"); |