Commit | Line | Data |
---|---|---|
61e3d0f7 WS |
1 | /* |
2 | * Linux I2C core | |
3 | * | |
4 | * Copyright (C) 1995-99 Simon G. Vogl | |
5 | * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> | |
6 | * Mux support by Rodolfo Giometti <giometti@enneenne.com> and | |
7 | * Michael Lawnick <michael.lawnick.ext@nsn.com> | |
8 | * | |
9 | * Copyright (C) 2013-2017 Wolfram Sang <wsa@the-dreams.de> | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify it | |
12 | * under the terms of the GNU General Public License as published by the Free | |
13 | * Software Foundation; either version 2 of the License, or (at your option) | |
14 | * any later version. | |
15 | * | |
16 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
17 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | |
18 | * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. | |
687b81d0 | 19 | */ |
1da177e4 | 20 | |
44239a5a WS |
21 | #define pr_fmt(fmt) "i2c-core: " fmt |
22 | ||
b4e2f6ac | 23 | #include <dt-bindings/i2c/i2c.h> |
53feedf8 WS |
24 | #include <linux/acpi.h> |
25 | #include <linux/clk/clk-conf.h> | |
26 | #include <linux/completion.h> | |
5f9296ba | 27 | #include <linux/delay.h> |
53feedf8 | 28 | #include <linux/err.h> |
1da177e4 | 29 | #include <linux/errno.h> |
10c9ef04 | 30 | #include <linux/gpio/consumer.h> |
1da177e4 | 31 | #include <linux/i2c.h> |
f8756c67 | 32 | #include <linux/i2c-smbus.h> |
1da177e4 | 33 | #include <linux/idr.h> |
53feedf8 WS |
34 | #include <linux/init.h> |
35 | #include <linux/irqflags.h> | |
36 | #include <linux/jump_label.h> | |
37 | #include <linux/kernel.h> | |
38 | #include <linux/module.h> | |
b3585e4f | 39 | #include <linux/mutex.h> |
959e85f7 | 40 | #include <linux/of_device.h> |
53feedf8 | 41 | #include <linux/of.h> |
687b81d0 | 42 | #include <linux/of_irq.h> |
f48c767c | 43 | #include <linux/pm_domain.h> |
53feedf8 | 44 | #include <linux/pm_runtime.h> |
3fffd128 | 45 | #include <linux/pm_wakeirq.h> |
e1dba01c | 46 | #include <linux/property.h> |
53feedf8 WS |
47 | #include <linux/rwsem.h> |
48 | #include <linux/slab.h> | |
1da177e4 | 49 | |
9c1600ed DB |
50 | #include "i2c-core.h" |
51 | ||
d9a83d62 DH |
52 | #define CREATE_TRACE_POINTS |
53 | #include <trace/events/i2c.h> | |
1da177e4 | 54 | |
da899f55 WS |
55 | #define I2C_ADDR_OFFSET_TEN_BIT 0xa000 |
56 | #define I2C_ADDR_OFFSET_SLAVE 0x1000 | |
57 | ||
4d5538f5 BT |
58 | #define I2C_ADDR_7BITS_MAX 0x77 |
59 | #define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1) | |
60 | ||
dde67eb1 PR |
61 | #define I2C_ADDR_DEVICE_ID 0x7c |
62 | ||
61e3d0f7 WS |
63 | /* |
64 | * core_lock protects i2c_adapter_idr, and guarantees that device detection, | |
0c36dd37 | 65 | * deletion of detected devices are serialized |
61e3d0f7 | 66 | */ |
caada32a | 67 | static DEFINE_MUTEX(core_lock); |
1da177e4 LT |
68 | static DEFINE_IDR(i2c_adapter_idr); |
69 | ||
4735c98f | 70 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
f37dd80a | 71 | |
50888b01 | 72 | static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key); |
95026658 | 73 | static bool is_registered; |
d9a83d62 | 74 | |
8cf868af | 75 | int i2c_transfer_trace_reg(void) |
d9a83d62 | 76 | { |
50888b01 | 77 | static_branch_inc(&i2c_trace_msg_key); |
8cf868af | 78 | return 0; |
d9a83d62 DH |
79 | } |
80 | ||
81 | void i2c_transfer_trace_unreg(void) | |
82 | { | |
50888b01 | 83 | static_branch_dec(&i2c_trace_msg_key); |
d9a83d62 DH |
84 | } |
85 | ||
5f441fca | 86 | const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
d2653e92 JD |
87 | const struct i2c_client *client) |
88 | { | |
811073b1 LJ |
89 | if (!(id && client)) |
90 | return NULL; | |
91 | ||
d2653e92 JD |
92 | while (id->name[0]) { |
93 | if (strcmp(client->name, id->name) == 0) | |
94 | return id; | |
95 | id++; | |
96 | } | |
97 | return NULL; | |
98 | } | |
5f441fca | 99 | EXPORT_SYMBOL_GPL(i2c_match_id); |
d2653e92 | 100 | |
1da177e4 LT |
101 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
102 | { | |
51298d12 JD |
103 | struct i2c_client *client = i2c_verify_client(dev); |
104 | struct i2c_driver *driver; | |
105 | ||
7b4fbc50 | 106 | |
959e85f7 | 107 | /* Attempt an OF style match */ |
da10c06a | 108 | if (i2c_of_match_device(drv->of_match_table, client)) |
959e85f7 GL |
109 | return 1; |
110 | ||
907ddf89 MW |
111 | /* Then ACPI style match */ |
112 | if (acpi_driver_match_device(dev, drv)) | |
113 | return 1; | |
114 | ||
51298d12 | 115 | driver = to_i2c_driver(drv); |
811073b1 LJ |
116 | |
117 | /* Finally an I2C match */ | |
118 | if (i2c_match_id(driver->id_table, client)) | |
119 | return 1; | |
d2653e92 | 120 | |
eb8a7908 | 121 | return 0; |
1da177e4 LT |
122 | } |
123 | ||
7eff2e7a | 124 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 | 125 | { |
8dcf3217 | 126 | struct i2c_client *client = to_i2c_client(dev); |
8c4ff6d0 ZR |
127 | int rc; |
128 | ||
af503716 JMC |
129 | rc = of_device_uevent_modalias(dev, env); |
130 | if (rc != -ENODEV) | |
131 | return rc; | |
132 | ||
8c4ff6d0 ZR |
133 | rc = acpi_device_uevent_modalias(dev, env); |
134 | if (rc != -ENODEV) | |
135 | return rc; | |
7b4fbc50 | 136 | |
8dcf3217 | 137 | return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
138 | } |
139 | ||
5f9296ba VK |
140 | /* i2c bus recovery routines */ |
141 | static int get_scl_gpio_value(struct i2c_adapter *adap) | |
142 | { | |
3991c5c8 | 143 | return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod); |
5f9296ba VK |
144 | } |
145 | ||
146 | static void set_scl_gpio_value(struct i2c_adapter *adap, int val) | |
147 | { | |
3991c5c8 | 148 | gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val); |
5f9296ba VK |
149 | } |
150 | ||
151 | static int get_sda_gpio_value(struct i2c_adapter *adap) | |
152 | { | |
3991c5c8 | 153 | return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod); |
5f9296ba VK |
154 | } |
155 | ||
8092178f | 156 | static void set_sda_gpio_value(struct i2c_adapter *adap, int val) |
5f9296ba | 157 | { |
8092178f | 158 | gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val); |
5f9296ba VK |
159 | } |
160 | ||
7ca5f6be WS |
161 | static int i2c_generic_bus_free(struct i2c_adapter *adap) |
162 | { | |
163 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
164 | int ret = -EOPNOTSUPP; | |
165 | ||
166 | if (bri->get_bus_free) | |
167 | ret = bri->get_bus_free(adap); | |
168 | else if (bri->get_sda) | |
169 | ret = bri->get_sda(adap); | |
170 | ||
171 | if (ret < 0) | |
172 | return ret; | |
173 | ||
174 | return ret ? 0 : -EBUSY; | |
175 | } | |
176 | ||
5f9296ba VK |
177 | /* |
178 | * We are generating clock pulses. ndelay() determines durating of clk pulses. | |
179 | * We will generate clock with rate 100 KHz and so duration of both clock levels | |
180 | * is: delay in ns = (10^6 / 100) / 2 | |
181 | */ | |
182 | #define RECOVERY_NDELAY 5000 | |
183 | #define RECOVERY_CLK_CNT 9 | |
184 | ||
e1eb7d28 | 185 | int i2c_generic_scl_recovery(struct i2c_adapter *adap) |
5f9296ba VK |
186 | { |
187 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
f7ff75e2 | 188 | int i = 0, scl = 1, ret; |
5f9296ba VK |
189 | |
190 | if (bri->prepare_recovery) | |
2b2190a3 | 191 | bri->prepare_recovery(adap); |
5f9296ba | 192 | |
c4ae05b9 WS |
193 | /* |
194 | * If we can set SDA, we will always create a STOP to ensure additional | |
195 | * pulses will do no harm. This is achieved by letting SDA follow SCL | |
196 | * half a cycle later. Check the 'incomplete_write_byte' fault injector | |
197 | * for details. | |
198 | */ | |
f7ff75e2 | 199 | bri->set_scl(adap, scl); |
c4ae05b9 | 200 | ndelay(RECOVERY_NDELAY / 2); |
72b08fcc | 201 | if (bri->set_sda) |
c4ae05b9 WS |
202 | bri->set_sda(adap, scl); |
203 | ndelay(RECOVERY_NDELAY / 2); | |
8b062608 | 204 | |
5f9296ba VK |
205 | /* |
206 | * By this time SCL is high, as we need to give 9 falling-rising edges | |
207 | */ | |
208 | while (i++ < RECOVERY_CLK_CNT * 2) { | |
f7ff75e2 | 209 | if (scl) { |
5f9296ba VK |
210 | /* SCL shouldn't be low here */ |
211 | if (!bri->get_scl(adap)) { | |
212 | dev_err(&adap->dev, | |
213 | "SCL is stuck low, exit recovery\n"); | |
214 | ret = -EBUSY; | |
215 | break; | |
216 | } | |
217 | } | |
218 | ||
f7ff75e2 WS |
219 | scl = !scl; |
220 | bri->set_scl(adap, scl); | |
c4ae05b9 | 221 | /* Creating STOP again, see above */ |
abe41184 WS |
222 | ndelay(RECOVERY_NDELAY / 2); |
223 | if (bri->set_sda) | |
f7ff75e2 | 224 | bri->set_sda(adap, scl); |
abe41184 | 225 | ndelay(RECOVERY_NDELAY / 2); |
1f35b865 | 226 | |
f7ff75e2 | 227 | if (scl) { |
7ca5f6be | 228 | ret = i2c_generic_bus_free(adap); |
0b71026c WS |
229 | if (ret == 0) |
230 | break; | |
231 | } | |
2806e6ad WS |
232 | } |
233 | ||
7ca5f6be WS |
234 | /* If we can't check bus status, assume recovery worked */ |
235 | if (ret == -EOPNOTSUPP) | |
236 | ret = 0; | |
237 | ||
5f9296ba | 238 | if (bri->unprepare_recovery) |
2b2190a3 | 239 | bri->unprepare_recovery(adap); |
5f9296ba VK |
240 | |
241 | return ret; | |
242 | } | |
c1c21f4e | 243 | EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery); |
5f9296ba | 244 | |
5f9296ba VK |
245 | int i2c_recover_bus(struct i2c_adapter *adap) |
246 | { | |
247 | if (!adap->bus_recovery_info) | |
248 | return -EOPNOTSUPP; | |
249 | ||
250 | dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); | |
251 | return adap->bus_recovery_info->recover_bus(adap); | |
252 | } | |
c1c21f4e | 253 | EXPORT_SYMBOL_GPL(i2c_recover_bus); |
5f9296ba | 254 | |
d3b11d83 WS |
255 | static void i2c_init_recovery(struct i2c_adapter *adap) |
256 | { | |
257 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
258 | char *err_str; | |
259 | ||
260 | if (!bri) | |
261 | return; | |
262 | ||
263 | if (!bri->recover_bus) { | |
264 | err_str = "no recover_bus() found"; | |
265 | goto err; | |
266 | } | |
267 | ||
3991c5c8 | 268 | if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) { |
d3b11d83 WS |
269 | bri->get_scl = get_scl_gpio_value; |
270 | bri->set_scl = set_scl_gpio_value; | |
8092178f | 271 | if (bri->sda_gpiod) { |
3991c5c8 | 272 | bri->get_sda = get_sda_gpio_value; |
8092178f WS |
273 | /* FIXME: add proper flag instead of '0' once available */ |
274 | if (gpiod_get_direction(bri->sda_gpiod) == 0) | |
275 | bri->set_sda = set_sda_gpio_value; | |
276 | } | |
3991c5c8 PR |
277 | return; |
278 | } | |
279 | ||
e1eb7d28 | 280 | if (bri->recover_bus == i2c_generic_scl_recovery) { |
d3b11d83 WS |
281 | /* Generic SCL recovery */ |
282 | if (!bri->set_scl || !bri->get_scl) { | |
283 | err_str = "no {get|set}_scl() found"; | |
284 | goto err; | |
285 | } | |
ffc59c49 WS |
286 | if (!bri->set_sda && !bri->get_sda) { |
287 | err_str = "either get_sda() or set_sda() needed"; | |
288 | goto err; | |
289 | } | |
d3b11d83 WS |
290 | } |
291 | ||
292 | return; | |
293 | err: | |
294 | dev_err(&adap->dev, "Not using recovery: %s\n", err_str); | |
295 | adap->bus_recovery_info = NULL; | |
296 | } | |
297 | ||
4d5538f5 BT |
298 | static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client) |
299 | { | |
300 | struct i2c_adapter *adap = client->adapter; | |
301 | unsigned int irq; | |
302 | ||
303 | if (!adap->host_notify_domain) | |
304 | return -ENXIO; | |
305 | ||
306 | if (client->flags & I2C_CLIENT_TEN) | |
307 | return -EINVAL; | |
308 | ||
b9bb3fdf | 309 | irq = irq_create_mapping(adap->host_notify_domain, client->addr); |
4d5538f5 BT |
310 | |
311 | return irq > 0 ? irq : -ENXIO; | |
312 | } | |
313 | ||
f37dd80a | 314 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 315 | { |
51298d12 JD |
316 | struct i2c_client *client = i2c_verify_client(dev); |
317 | struct i2c_driver *driver; | |
50c3304a | 318 | int status; |
7b4fbc50 | 319 | |
51298d12 JD |
320 | if (!client) |
321 | return 0; | |
322 | ||
d1d84bb9 HG |
323 | driver = to_i2c_driver(dev->driver); |
324 | ||
325 | if (!client->irq && !driver->disable_i2c_core_irq_mapping) { | |
845c8770 MW |
326 | int irq = -ENOENT; |
327 | ||
331c3425 DT |
328 | if (client->flags & I2C_CLIENT_HOST_NOTIFY) { |
329 | dev_dbg(dev, "Using Host Notify IRQ\n"); | |
330 | irq = i2c_smbus_host_notify_to_irq(client); | |
331 | } else if (dev->of_node) { | |
3fffd128 DT |
332 | irq = of_irq_get_byname(dev->of_node, "irq"); |
333 | if (irq == -EINVAL || irq == -ENODATA) | |
334 | irq = of_irq_get(dev->of_node, 0); | |
335 | } else if (ACPI_COMPANION(dev)) { | |
845c8770 | 336 | irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0); |
3fffd128 | 337 | } |
6f34be74 | 338 | if (irq == -EPROBE_DEFER) |
2fd36c55 | 339 | return irq; |
331c3425 | 340 | |
6f34be74 GU |
341 | if (irq < 0) |
342 | irq = 0; | |
2fd36c55 LP |
343 | |
344 | client->irq = irq; | |
345 | } | |
346 | ||
da10c06a | 347 | /* |
f4b17a14 JMC |
348 | * An I2C ID table is not mandatory, if and only if, a suitable OF |
349 | * or ACPI ID table is supplied for the probing device. | |
da10c06a LJ |
350 | */ |
351 | if (!driver->id_table && | |
c64ffff7 | 352 | !i2c_acpi_match_device(dev->driver->acpi_match_table, client) && |
da10c06a | 353 | !i2c_of_match_device(dev->driver->of_match_table, client)) |
7b4fbc50 | 354 | return -ENODEV; |
0acc2b32 | 355 | |
3fffd128 DT |
356 | if (client->flags & I2C_CLIENT_WAKE) { |
357 | int wakeirq = -ENOENT; | |
358 | ||
359 | if (dev->of_node) { | |
360 | wakeirq = of_irq_get_byname(dev->of_node, "wakeup"); | |
361 | if (wakeirq == -EPROBE_DEFER) | |
362 | return wakeirq; | |
363 | } | |
364 | ||
365 | device_init_wakeup(&client->dev, true); | |
366 | ||
367 | if (wakeirq > 0 && wakeirq != client->irq) | |
368 | status = dev_pm_set_dedicated_wake_irq(dev, wakeirq); | |
369 | else if (client->irq > 0) | |
c18fba23 | 370 | status = dev_pm_set_wake_irq(dev, client->irq); |
3fffd128 DT |
371 | else |
372 | status = 0; | |
373 | ||
374 | if (status) | |
b93d3d37 | 375 | dev_warn(&client->dev, "failed to set up wakeup irq\n"); |
3fffd128 DT |
376 | } |
377 | ||
7b4fbc50 | 378 | dev_dbg(dev, "probe\n"); |
d2653e92 | 379 | |
86be408b SN |
380 | status = of_clk_set_defaults(dev->of_node, false); |
381 | if (status < 0) | |
3fffd128 | 382 | goto err_clear_wakeup_irq; |
86be408b | 383 | |
e09b0d4e | 384 | status = dev_pm_domain_attach(&client->dev, true); |
e6a20b6c | 385 | if (status) |
74cedd30 KB |
386 | goto err_clear_wakeup_irq; |
387 | ||
b8a1a4cd LJ |
388 | /* |
389 | * When there are no more users of probe(), | |
390 | * rename probe_new to probe. | |
391 | */ | |
392 | if (driver->probe_new) | |
393 | status = driver->probe_new(client); | |
394 | else if (driver->probe) | |
395 | status = driver->probe(client, | |
396 | i2c_match_id(driver->id_table, client)); | |
397 | else | |
398 | status = -EINVAL; | |
399 | ||
74cedd30 KB |
400 | if (status) |
401 | goto err_detach_pm_domain; | |
72fa818e | 402 | |
3fffd128 DT |
403 | return 0; |
404 | ||
405 | err_detach_pm_domain: | |
406 | dev_pm_domain_detach(&client->dev, true); | |
407 | err_clear_wakeup_irq: | |
408 | dev_pm_clear_wake_irq(&client->dev); | |
409 | device_init_wakeup(&client->dev, false); | |
50c3304a | 410 | return status; |
f37dd80a | 411 | } |
1da177e4 | 412 | |
f37dd80a DB |
413 | static int i2c_device_remove(struct device *dev) |
414 | { | |
51298d12 | 415 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 | 416 | struct i2c_driver *driver; |
72fa818e | 417 | int status = 0; |
a1d9e6e4 | 418 | |
51298d12 | 419 | if (!client || !dev->driver) |
a1d9e6e4 DB |
420 | return 0; |
421 | ||
422 | driver = to_i2c_driver(dev->driver); | |
423 | if (driver->remove) { | |
424 | dev_dbg(dev, "remove\n"); | |
425 | status = driver->remove(client); | |
a1d9e6e4 | 426 | } |
72fa818e | 427 | |
e09b0d4e | 428 | dev_pm_domain_detach(&client->dev, true); |
3fffd128 DT |
429 | |
430 | dev_pm_clear_wake_irq(&client->dev); | |
431 | device_init_wakeup(&client->dev, false); | |
432 | ||
6f108dd7 CK |
433 | client->irq = 0; |
434 | ||
a1d9e6e4 | 435 | return status; |
1da177e4 LT |
436 | } |
437 | ||
f37dd80a | 438 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 439 | { |
51298d12 | 440 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
441 | struct i2c_driver *driver; |
442 | ||
51298d12 | 443 | if (!client || !dev->driver) |
f37dd80a DB |
444 | return; |
445 | driver = to_i2c_driver(dev->driver); | |
446 | if (driver->shutdown) | |
51298d12 | 447 | driver->shutdown(client); |
1da177e4 LT |
448 | } |
449 | ||
9c1600ed DB |
450 | static void i2c_client_dev_release(struct device *dev) |
451 | { | |
452 | kfree(to_i2c_client(dev)); | |
453 | } | |
454 | ||
09b8ce0a | 455 | static ssize_t |
4f8cf824 | 456 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 457 | { |
4f8cf824 JD |
458 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
459 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 | 460 | } |
a5eb71b2 | 461 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
7b4fbc50 | 462 | |
09b8ce0a ZX |
463 | static ssize_t |
464 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
465 | { |
466 | struct i2c_client *client = to_i2c_client(dev); | |
8c4ff6d0 ZR |
467 | int len; |
468 | ||
af503716 JMC |
469 | len = of_device_modalias(dev, buf, PAGE_SIZE); |
470 | if (len != -ENODEV) | |
471 | return len; | |
472 | ||
8c4ff6d0 ZR |
473 | len = acpi_device_modalias(dev, buf, PAGE_SIZE -1); |
474 | if (len != -ENODEV) | |
475 | return len; | |
476 | ||
eb8a7908 | 477 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 | 478 | } |
51298d12 JD |
479 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
480 | ||
481 | static struct attribute *i2c_dev_attrs[] = { | |
482 | &dev_attr_name.attr, | |
7b4fbc50 | 483 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
484 | &dev_attr_modalias.attr, |
485 | NULL | |
486 | }; | |
a5eb71b2 | 487 | ATTRIBUTE_GROUPS(i2c_dev); |
54067ee2 | 488 | |
e9ca9eb9 | 489 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
490 | .name = "i2c", |
491 | .match = i2c_device_match, | |
492 | .probe = i2c_device_probe, | |
493 | .remove = i2c_device_remove, | |
494 | .shutdown = i2c_device_shutdown, | |
b864c7d5 | 495 | }; |
e9ca9eb9 | 496 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 497 | |
00a06c22 | 498 | struct device_type i2c_client_type = { |
a5eb71b2 | 499 | .groups = i2c_dev_groups, |
51298d12 JD |
500 | .uevent = i2c_device_uevent, |
501 | .release = i2c_client_dev_release, | |
502 | }; | |
00a06c22 | 503 | EXPORT_SYMBOL_GPL(i2c_client_type); |
51298d12 | 504 | |
9b766b81 DB |
505 | |
506 | /** | |
507 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
508 | * @dev: device, probably from some driver model iterator | |
509 | * | |
510 | * When traversing the driver model tree, perhaps using driver model | |
511 | * iterators like @device_for_each_child(), you can't assume very much | |
512 | * about the nodes you find. Use this function to avoid oopses caused | |
513 | * by wrongly treating some non-I2C device as an i2c_client. | |
514 | */ | |
515 | struct i2c_client *i2c_verify_client(struct device *dev) | |
516 | { | |
51298d12 | 517 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
518 | ? to_i2c_client(dev) |
519 | : NULL; | |
520 | } | |
521 | EXPORT_SYMBOL(i2c_verify_client); | |
522 | ||
523 | ||
da899f55 WS |
524 | /* Return a unique address which takes the flags of the client into account */ |
525 | static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client) | |
526 | { | |
527 | unsigned short addr = client->addr; | |
528 | ||
529 | /* For some client flags, add an arbitrary offset to avoid collisions */ | |
530 | if (client->flags & I2C_CLIENT_TEN) | |
531 | addr |= I2C_ADDR_OFFSET_TEN_BIT; | |
532 | ||
533 | if (client->flags & I2C_CLIENT_SLAVE) | |
534 | addr |= I2C_ADDR_OFFSET_SLAVE; | |
535 | ||
536 | return addr; | |
537 | } | |
538 | ||
3a89db5f | 539 | /* This is a permissive address validity check, I2C address map constraints |
25985edc | 540 | * are purposely not enforced, except for the general call address. */ |
398432ed | 541 | static int i2c_check_addr_validity(unsigned int addr, unsigned short flags) |
3a89db5f | 542 | { |
c4019b70 | 543 | if (flags & I2C_CLIENT_TEN) { |
3a89db5f | 544 | /* 10-bit address, all values are valid */ |
c4019b70 | 545 | if (addr > 0x3ff) |
3a89db5f JD |
546 | return -EINVAL; |
547 | } else { | |
548 | /* 7-bit address, reject the general call address */ | |
c4019b70 | 549 | if (addr == 0x00 || addr > 0x7f) |
3a89db5f JD |
550 | return -EINVAL; |
551 | } | |
552 | return 0; | |
553 | } | |
554 | ||
656b8761 JD |
555 | /* And this is a strict address validity check, used when probing. If a |
556 | * device uses a reserved address, then it shouldn't be probed. 7-bit | |
557 | * addressing is assumed, 10-bit address devices are rare and should be | |
558 | * explicitly enumerated. */ | |
e4991ecd | 559 | int i2c_check_7bit_addr_validity_strict(unsigned short addr) |
656b8761 JD |
560 | { |
561 | /* | |
562 | * Reserved addresses per I2C specification: | |
563 | * 0x00 General call address / START byte | |
564 | * 0x01 CBUS address | |
565 | * 0x02 Reserved for different bus format | |
566 | * 0x03 Reserved for future purposes | |
567 | * 0x04-0x07 Hs-mode master code | |
568 | * 0x78-0x7b 10-bit slave addressing | |
569 | * 0x7c-0x7f Reserved for future purposes | |
570 | */ | |
571 | if (addr < 0x08 || addr > 0x77) | |
572 | return -EINVAL; | |
573 | return 0; | |
574 | } | |
575 | ||
3b5f794b JD |
576 | static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
577 | { | |
578 | struct i2c_client *client = i2c_verify_client(dev); | |
579 | int addr = *(int *)addrp; | |
580 | ||
9bccc70a | 581 | if (client && i2c_encode_flags_to_addr(client) == addr) |
3b5f794b JD |
582 | return -EBUSY; |
583 | return 0; | |
584 | } | |
585 | ||
0826374b ML |
586 | /* walk up mux tree */ |
587 | static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
588 | { | |
97cc4d49 | 589 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
590 | int result; |
591 | ||
592 | result = device_for_each_child(&adapter->dev, &addr, | |
593 | __i2c_check_addr_busy); | |
594 | ||
97cc4d49 JD |
595 | if (!result && parent) |
596 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
597 | |
598 | return result; | |
599 | } | |
600 | ||
601 | /* recurse down mux tree */ | |
602 | static int i2c_check_mux_children(struct device *dev, void *addrp) | |
603 | { | |
604 | int result; | |
605 | ||
606 | if (dev->type == &i2c_adapter_type) | |
607 | result = device_for_each_child(dev, addrp, | |
608 | i2c_check_mux_children); | |
609 | else | |
610 | result = __i2c_check_addr_busy(dev, addrp); | |
611 | ||
612 | return result; | |
613 | } | |
614 | ||
3b5f794b JD |
615 | static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) |
616 | { | |
97cc4d49 | 617 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
618 | int result = 0; |
619 | ||
97cc4d49 JD |
620 | if (parent) |
621 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
622 | |
623 | if (!result) | |
624 | result = device_for_each_child(&adapter->dev, &addr, | |
625 | i2c_check_mux_children); | |
626 | ||
627 | return result; | |
3b5f794b JD |
628 | } |
629 | ||
fe61e07e | 630 | /** |
8320f495 | 631 | * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment |
fe61e07e | 632 | * @adapter: Target I2C bus segment |
8320f495 PR |
633 | * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT |
634 | * locks only this branch in the adapter tree | |
fe61e07e | 635 | */ |
8320f495 PR |
636 | static void i2c_adapter_lock_bus(struct i2c_adapter *adapter, |
637 | unsigned int flags) | |
fe61e07e | 638 | { |
7b94ea50 | 639 | rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter)); |
fe61e07e | 640 | } |
fe61e07e JD |
641 | |
642 | /** | |
8320f495 | 643 | * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment |
fe61e07e | 644 | * @adapter: Target I2C bus segment |
8320f495 PR |
645 | * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT |
646 | * trylocks only this branch in the adapter tree | |
fe61e07e | 647 | */ |
8320f495 PR |
648 | static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter, |
649 | unsigned int flags) | |
fe61e07e | 650 | { |
fa96f0cb | 651 | return rt_mutex_trylock(&adapter->bus_lock); |
fe61e07e JD |
652 | } |
653 | ||
654 | /** | |
8320f495 | 655 | * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment |
fe61e07e | 656 | * @adapter: Target I2C bus segment |
8320f495 PR |
657 | * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT |
658 | * unlocks only this branch in the adapter tree | |
fe61e07e | 659 | */ |
8320f495 PR |
660 | static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter, |
661 | unsigned int flags) | |
fe61e07e | 662 | { |
fa96f0cb | 663 | rt_mutex_unlock(&adapter->bus_lock); |
fe61e07e | 664 | } |
fe61e07e | 665 | |
70762abb | 666 | static void i2c_dev_set_name(struct i2c_adapter *adap, |
728fe6ce HG |
667 | struct i2c_client *client, |
668 | struct i2c_board_info const *info) | |
70762abb JN |
669 | { |
670 | struct acpi_device *adev = ACPI_COMPANION(&client->dev); | |
671 | ||
728fe6ce HG |
672 | if (info && info->dev_name) { |
673 | dev_set_name(&client->dev, "i2c-%s", info->dev_name); | |
674 | return; | |
675 | } | |
676 | ||
70762abb JN |
677 | if (adev) { |
678 | dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); | |
679 | return; | |
680 | } | |
681 | ||
70762abb | 682 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), |
da899f55 | 683 | i2c_encode_flags_to_addr(client)); |
70762abb JN |
684 | } |
685 | ||
4124c4eb DT |
686 | static int i2c_dev_irq_from_resources(const struct resource *resources, |
687 | unsigned int num_resources) | |
688 | { | |
689 | struct irq_data *irqd; | |
690 | int i; | |
691 | ||
692 | for (i = 0; i < num_resources; i++) { | |
693 | const struct resource *r = &resources[i]; | |
694 | ||
695 | if (resource_type(r) != IORESOURCE_IRQ) | |
696 | continue; | |
697 | ||
698 | if (r->flags & IORESOURCE_BITS) { | |
699 | irqd = irq_get_irq_data(r->start); | |
700 | if (!irqd) | |
701 | break; | |
702 | ||
703 | irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); | |
704 | } | |
705 | ||
706 | return r->start; | |
707 | } | |
708 | ||
709 | return 0; | |
710 | } | |
711 | ||
9c1600ed | 712 | /** |
f8a227e8 | 713 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
714 | * @adap: the adapter managing the device |
715 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 716 | * Context: can sleep |
9c1600ed | 717 | * |
f8a227e8 JD |
718 | * Create an i2c device. Binding is handled through driver model |
719 | * probe()/remove() methods. A driver may be bound to this device when we | |
720 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
721 | * load the driver module). This call is not appropriate for use by mainboard | |
722 | * initialization logic, which usually runs during an arch_initcall() long | |
723 | * before any i2c_adapter could exist. | |
9c1600ed DB |
724 | * |
725 | * This returns the new i2c client, which may be saved for later use with | |
726 | * i2c_unregister_device(); or NULL to indicate an error. | |
727 | */ | |
728 | struct i2c_client * | |
729 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
730 | { | |
731 | struct i2c_client *client; | |
732 | int status; | |
733 | ||
734 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
735 | if (!client) | |
736 | return NULL; | |
737 | ||
738 | client->adapter = adap; | |
739 | ||
740 | client->dev.platform_data = info->platform_data; | |
ee35425c | 741 | client->flags = info->flags; |
9c1600ed | 742 | client->addr = info->addr; |
4124c4eb | 743 | |
9c1600ed | 744 | client->irq = info->irq; |
4124c4eb DT |
745 | if (!client->irq) |
746 | client->irq = i2c_dev_irq_from_resources(info->resources, | |
747 | info->num_resources); | |
9c1600ed | 748 | |
9c1600ed DB |
749 | strlcpy(client->name, info->type, sizeof(client->name)); |
750 | ||
c4019b70 | 751 | status = i2c_check_addr_validity(client->addr, client->flags); |
3a89db5f JD |
752 | if (status) { |
753 | dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", | |
754 | client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); | |
755 | goto out_err_silent; | |
756 | } | |
757 | ||
f8a227e8 | 758 | /* Check for address business */ |
9bccc70a | 759 | status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client)); |
f8a227e8 JD |
760 | if (status) |
761 | goto out_err; | |
762 | ||
763 | client->dev.parent = &client->adapter->dev; | |
764 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 765 | client->dev.type = &i2c_client_type; |
04782265 | 766 | client->dev.of_node = of_node_get(info->of_node); |
ce793486 | 767 | client->dev.fwnode = info->fwnode; |
f8a227e8 | 768 | |
728fe6ce | 769 | i2c_dev_set_name(adap, client, info); |
d3e1b617 DT |
770 | |
771 | if (info->properties) { | |
772 | status = device_add_properties(&client->dev, info->properties); | |
773 | if (status) { | |
774 | dev_err(&adap->dev, | |
775 | "Failed to add properties to client %s: %d\n", | |
776 | client->name, status); | |
04782265 | 777 | goto out_err_put_of_node; |
d3e1b617 DT |
778 | } |
779 | } | |
780 | ||
f8a227e8 JD |
781 | status = device_register(&client->dev); |
782 | if (status) | |
d3e1b617 | 783 | goto out_free_props; |
f8a227e8 | 784 | |
f8a227e8 JD |
785 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
786 | client->name, dev_name(&client->dev)); | |
787 | ||
9c1600ed | 788 | return client; |
f8a227e8 | 789 | |
d3e1b617 DT |
790 | out_free_props: |
791 | if (info->properties) | |
792 | device_remove_properties(&client->dev); | |
04782265 BB |
793 | out_err_put_of_node: |
794 | of_node_put(info->of_node); | |
f8a227e8 | 795 | out_err: |
b93d3d37 AS |
796 | dev_err(&adap->dev, |
797 | "Failed to register i2c client %s at 0x%02x (%d)\n", | |
798 | client->name, client->addr, status); | |
3a89db5f | 799 | out_err_silent: |
f8a227e8 JD |
800 | kfree(client); |
801 | return NULL; | |
9c1600ed DB |
802 | } |
803 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
804 | ||
805 | ||
806 | /** | |
807 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
808 | * @client: value returned from i2c_new_device() | |
d64f73be | 809 | * Context: can sleep |
9c1600ed DB |
810 | */ |
811 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 812 | { |
7b43dd19 AS |
813 | if (!client) |
814 | return; | |
e0638fa4 LW |
815 | |
816 | if (client->dev.of_node) { | |
4f001fd3 | 817 | of_node_clear_flag(client->dev.of_node, OF_POPULATED); |
e0638fa4 LW |
818 | of_node_put(client->dev.of_node); |
819 | } | |
820 | ||
525e6fab OP |
821 | if (ACPI_COMPANION(&client->dev)) |
822 | acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev)); | |
a1d9e6e4 DB |
823 | device_unregister(&client->dev); |
824 | } | |
9c1600ed | 825 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
826 | |
827 | ||
60b129d7 JD |
828 | static const struct i2c_device_id dummy_id[] = { |
829 | { "dummy", 0 }, | |
830 | { }, | |
831 | }; | |
832 | ||
d2653e92 JD |
833 | static int dummy_probe(struct i2c_client *client, |
834 | const struct i2c_device_id *id) | |
835 | { | |
836 | return 0; | |
837 | } | |
838 | ||
839 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
840 | { |
841 | return 0; | |
842 | } | |
843 | ||
844 | static struct i2c_driver dummy_driver = { | |
845 | .driver.name = "dummy", | |
d2653e92 JD |
846 | .probe = dummy_probe, |
847 | .remove = dummy_remove, | |
60b129d7 | 848 | .id_table = dummy_id, |
e9f1373b DB |
849 | }; |
850 | ||
851 | /** | |
852 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
853 | * @adapter: the adapter managing the device | |
854 | * @address: seven bit address to be used | |
e9f1373b DB |
855 | * Context: can sleep |
856 | * | |
857 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
858 | * with devices that consume multiple addresses. Examples of such chips | |
859 | * include various EEPROMS (like 24c04 and 24c08 models). | |
860 | * | |
861 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
862 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
863 | * And second, this prevents the specified address from being bound to a | |
864 | * different driver. | |
865 | * | |
866 | * This returns the new i2c client, which should be saved for later use with | |
867 | * i2c_unregister_device(); or NULL to indicate an error. | |
868 | */ | |
09b8ce0a | 869 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
870 | { |
871 | struct i2c_board_info info = { | |
60b129d7 | 872 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
873 | }; |
874 | ||
e9f1373b DB |
875 | return i2c_new_device(adapter, &info); |
876 | } | |
877 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
878 | ||
0f614d83 JMH |
879 | /** |
880 | * i2c_new_secondary_device - Helper to get the instantiated secondary address | |
881 | * and create the associated device | |
882 | * @client: Handle to the primary client | |
883 | * @name: Handle to specify which secondary address to get | |
884 | * @default_addr: Used as a fallback if no secondary address was specified | |
885 | * Context: can sleep | |
886 | * | |
887 | * I2C clients can be composed of multiple I2C slaves bound together in a single | |
888 | * component. The I2C client driver then binds to the master I2C slave and needs | |
889 | * to create I2C dummy clients to communicate with all the other slaves. | |
890 | * | |
891 | * This function creates and returns an I2C dummy client whose I2C address is | |
892 | * retrieved from the platform firmware based on the given slave name. If no | |
893 | * address is specified by the firmware default_addr is used. | |
894 | * | |
895 | * On DT-based platforms the address is retrieved from the "reg" property entry | |
896 | * cell whose "reg-names" value matches the slave name. | |
897 | * | |
898 | * This returns the new i2c client, which should be saved for later use with | |
899 | * i2c_unregister_device(); or NULL to indicate an error. | |
900 | */ | |
901 | struct i2c_client *i2c_new_secondary_device(struct i2c_client *client, | |
902 | const char *name, | |
903 | u16 default_addr) | |
904 | { | |
905 | struct device_node *np = client->dev.of_node; | |
906 | u32 addr = default_addr; | |
907 | int i; | |
908 | ||
909 | if (np) { | |
910 | i = of_property_match_string(np, "reg-names", name); | |
911 | if (i >= 0) | |
912 | of_property_read_u32_index(np, "reg", i, &addr); | |
913 | } | |
914 | ||
915 | dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr); | |
916 | return i2c_new_dummy(client->adapter, addr); | |
917 | } | |
918 | EXPORT_SYMBOL_GPL(i2c_new_secondary_device); | |
919 | ||
f37dd80a DB |
920 | /* ------------------------------------------------------------------------- */ |
921 | ||
16ffadfc DB |
922 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
923 | ||
83eaaed0 | 924 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 925 | { |
ef2c8321 | 926 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
927 | complete(&adap->dev_released); |
928 | } | |
929 | ||
8dd1fe15 | 930 | unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) |
390946b1 JD |
931 | { |
932 | unsigned int depth = 0; | |
933 | ||
934 | while ((adapter = i2c_parent_is_i2c_adapter(adapter))) | |
935 | depth++; | |
936 | ||
2771dc34 BG |
937 | WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES, |
938 | "adapter depth exceeds lockdep subclass limit\n"); | |
939 | ||
390946b1 JD |
940 | return depth; |
941 | } | |
8dd1fe15 | 942 | EXPORT_SYMBOL_GPL(i2c_adapter_depth); |
390946b1 | 943 | |
99cd8e25 JD |
944 | /* |
945 | * Let users instantiate I2C devices through sysfs. This can be used when | |
946 | * platform initialization code doesn't contain the proper data for | |
947 | * whatever reason. Also useful for drivers that do device detection and | |
948 | * detection fails, either because the device uses an unexpected address, | |
949 | * or this is a compatible device with different ID register values. | |
950 | * | |
951 | * Parameter checking may look overzealous, but we really don't want | |
952 | * the user to provide incorrect parameters. | |
953 | */ | |
954 | static ssize_t | |
955 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
956 | const char *buf, size_t count) | |
957 | { | |
958 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
959 | struct i2c_board_info info; | |
960 | struct i2c_client *client; | |
961 | char *blank, end; | |
962 | int res; | |
963 | ||
99cd8e25 JD |
964 | memset(&info, 0, sizeof(struct i2c_board_info)); |
965 | ||
966 | blank = strchr(buf, ' '); | |
967 | if (!blank) { | |
968 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
969 | return -EINVAL; | |
970 | } | |
971 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
972 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
973 | return -EINVAL; | |
974 | } | |
975 | memcpy(info.type, buf, blank - buf); | |
976 | ||
977 | /* Parse remaining parameters, reject extra parameters */ | |
978 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
979 | if (res < 1) { | |
980 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
981 | return -EINVAL; | |
982 | } | |
983 | if (res > 1 && end != '\n') { | |
984 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
985 | return -EINVAL; | |
986 | } | |
987 | ||
cfa0327b WS |
988 | if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) { |
989 | info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT; | |
990 | info.flags |= I2C_CLIENT_TEN; | |
991 | } | |
992 | ||
993 | if (info.addr & I2C_ADDR_OFFSET_SLAVE) { | |
994 | info.addr &= ~I2C_ADDR_OFFSET_SLAVE; | |
995 | info.flags |= I2C_CLIENT_SLAVE; | |
996 | } | |
997 | ||
99cd8e25 JD |
998 | client = i2c_new_device(adap, &info); |
999 | if (!client) | |
3a89db5f | 1000 | return -EINVAL; |
99cd8e25 JD |
1001 | |
1002 | /* Keep track of the added device */ | |
dafc50d1 | 1003 | mutex_lock(&adap->userspace_clients_lock); |
6629dcff | 1004 | list_add_tail(&client->detected, &adap->userspace_clients); |
dafc50d1 | 1005 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
1006 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
1007 | info.type, info.addr); | |
1008 | ||
1009 | return count; | |
1010 | } | |
a5eb71b2 | 1011 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
99cd8e25 JD |
1012 | |
1013 | /* | |
1014 | * And of course let the users delete the devices they instantiated, if | |
1015 | * they got it wrong. This interface can only be used to delete devices | |
1016 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
1017 | * don't delete devices to which some kernel code still has references. | |
1018 | * | |
1019 | * Parameter checking may look overzealous, but we really don't want | |
1020 | * the user to delete the wrong device. | |
1021 | */ | |
1022 | static ssize_t | |
1023 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
1024 | const char *buf, size_t count) | |
1025 | { | |
1026 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
1027 | struct i2c_client *client, *next; | |
1028 | unsigned short addr; | |
1029 | char end; | |
1030 | int res; | |
1031 | ||
1032 | /* Parse parameters, reject extra parameters */ | |
1033 | res = sscanf(buf, "%hi%c", &addr, &end); | |
1034 | if (res < 1) { | |
1035 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
1036 | return -EINVAL; | |
1037 | } | |
1038 | if (res > 1 && end != '\n') { | |
1039 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
1040 | return -EINVAL; | |
1041 | } | |
1042 | ||
1043 | /* Make sure the device was added through sysfs */ | |
1044 | res = -ENOENT; | |
390946b1 JD |
1045 | mutex_lock_nested(&adap->userspace_clients_lock, |
1046 | i2c_adapter_depth(adap)); | |
6629dcff JD |
1047 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1048 | detected) { | |
cfa0327b | 1049 | if (i2c_encode_flags_to_addr(client) == addr) { |
99cd8e25 JD |
1050 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
1051 | "delete_device", client->name, client->addr); | |
1052 | ||
1053 | list_del(&client->detected); | |
1054 | i2c_unregister_device(client); | |
1055 | res = count; | |
1056 | break; | |
1057 | } | |
1058 | } | |
dafc50d1 | 1059 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
1060 | |
1061 | if (res < 0) | |
1062 | dev_err(dev, "%s: Can't find device in list\n", | |
1063 | "delete_device"); | |
1064 | return res; | |
1065 | } | |
e9b526fe AS |
1066 | static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, |
1067 | i2c_sysfs_delete_device); | |
4f8cf824 JD |
1068 | |
1069 | static struct attribute *i2c_adapter_attrs[] = { | |
1070 | &dev_attr_name.attr, | |
1071 | &dev_attr_new_device.attr, | |
1072 | &dev_attr_delete_device.attr, | |
1073 | NULL | |
1074 | }; | |
a5eb71b2 | 1075 | ATTRIBUTE_GROUPS(i2c_adapter); |
b119dc3f | 1076 | |
0826374b | 1077 | struct device_type i2c_adapter_type = { |
a5eb71b2 | 1078 | .groups = i2c_adapter_groups, |
4f8cf824 | 1079 | .release = i2c_adapter_dev_release, |
1da177e4 | 1080 | }; |
0826374b | 1081 | EXPORT_SYMBOL_GPL(i2c_adapter_type); |
1da177e4 | 1082 | |
643dd09e SW |
1083 | /** |
1084 | * i2c_verify_adapter - return parameter as i2c_adapter or NULL | |
1085 | * @dev: device, probably from some driver model iterator | |
1086 | * | |
1087 | * When traversing the driver model tree, perhaps using driver model | |
1088 | * iterators like @device_for_each_child(), you can't assume very much | |
1089 | * about the nodes you find. Use this function to avoid oopses caused | |
1090 | * by wrongly treating some non-I2C device as an i2c_adapter. | |
1091 | */ | |
1092 | struct i2c_adapter *i2c_verify_adapter(struct device *dev) | |
1093 | { | |
1094 | return (dev->type == &i2c_adapter_type) | |
1095 | ? to_i2c_adapter(dev) | |
1096 | : NULL; | |
1097 | } | |
1098 | EXPORT_SYMBOL(i2c_verify_adapter); | |
1099 | ||
2bb5095a JD |
1100 | #ifdef CONFIG_I2C_COMPAT |
1101 | static struct class_compat *i2c_adapter_compat_class; | |
1102 | #endif | |
1103 | ||
9c1600ed DB |
1104 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
1105 | { | |
1106 | struct i2c_devinfo *devinfo; | |
1107 | ||
f18c41da | 1108 | down_read(&__i2c_board_lock); |
9c1600ed DB |
1109 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
1110 | if (devinfo->busnum == adapter->nr | |
1111 | && !i2c_new_device(adapter, | |
1112 | &devinfo->board_info)) | |
09b8ce0a ZX |
1113 | dev_err(&adapter->dev, |
1114 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
1115 | devinfo->board_info.addr); |
1116 | } | |
f18c41da | 1117 | up_read(&__i2c_board_lock); |
9c1600ed DB |
1118 | } |
1119 | ||
69b0089a JD |
1120 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
1121 | struct i2c_adapter *adap) | |
026526f5 | 1122 | { |
4735c98f JD |
1123 | /* Detect supported devices on that bus, and instantiate them */ |
1124 | i2c_detect(adap, driver); | |
1125 | ||
026526f5 JD |
1126 | return 0; |
1127 | } | |
1128 | ||
69b0089a JD |
1129 | static int __process_new_adapter(struct device_driver *d, void *data) |
1130 | { | |
1131 | return i2c_do_add_adapter(to_i2c_driver(d), data); | |
1132 | } | |
1133 | ||
d1ed7985 PR |
1134 | static const struct i2c_lock_operations i2c_adapter_lock_ops = { |
1135 | .lock_bus = i2c_adapter_lock_bus, | |
1136 | .trylock_bus = i2c_adapter_trylock_bus, | |
1137 | .unlock_bus = i2c_adapter_unlock_bus, | |
1138 | }; | |
1139 | ||
4d5538f5 BT |
1140 | static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap) |
1141 | { | |
1142 | struct irq_domain *domain = adap->host_notify_domain; | |
1143 | irq_hw_number_t hwirq; | |
1144 | ||
1145 | if (!domain) | |
1146 | return; | |
1147 | ||
1148 | for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++) | |
1149 | irq_dispose_mapping(irq_find_mapping(domain, hwirq)); | |
1150 | ||
1151 | irq_domain_remove(domain); | |
1152 | adap->host_notify_domain = NULL; | |
1153 | } | |
1154 | ||
1155 | static int i2c_host_notify_irq_map(struct irq_domain *h, | |
1156 | unsigned int virq, | |
1157 | irq_hw_number_t hw_irq_num) | |
1158 | { | |
1159 | irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); | |
1160 | ||
1161 | return 0; | |
1162 | } | |
1163 | ||
1164 | static const struct irq_domain_ops i2c_host_notify_irq_ops = { | |
1165 | .map = i2c_host_notify_irq_map, | |
1166 | }; | |
1167 | ||
1168 | static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap) | |
1169 | { | |
1170 | struct irq_domain *domain; | |
1171 | ||
1172 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY)) | |
1173 | return 0; | |
1174 | ||
1175 | domain = irq_domain_create_linear(adap->dev.fwnode, | |
1176 | I2C_ADDR_7BITS_COUNT, | |
1177 | &i2c_host_notify_irq_ops, adap); | |
1178 | if (!domain) | |
1179 | return -ENOMEM; | |
1180 | ||
1181 | adap->host_notify_domain = domain; | |
1182 | ||
1183 | return 0; | |
1184 | } | |
1185 | ||
1186 | /** | |
1187 | * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct | |
1188 | * I2C client. | |
1189 | * @adap: the adapter | |
1190 | * @addr: the I2C address of the notifying device | |
1191 | * Context: can't sleep | |
1192 | * | |
1193 | * Helper function to be called from an I2C bus driver's interrupt | |
1194 | * handler. It will schedule the Host Notify IRQ. | |
1195 | */ | |
1196 | int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr) | |
1197 | { | |
1198 | int irq; | |
1199 | ||
1200 | if (!adap) | |
1201 | return -EINVAL; | |
1202 | ||
1203 | irq = irq_find_mapping(adap->host_notify_domain, addr); | |
1204 | if (irq <= 0) | |
1205 | return -ENXIO; | |
1206 | ||
1207 | generic_handle_irq(irq); | |
1208 | ||
1209 | return 0; | |
1210 | } | |
1211 | EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify); | |
1212 | ||
6e13e641 | 1213 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 1214 | { |
ce0dffaf | 1215 | int res = -EINVAL; |
1da177e4 | 1216 | |
1d0b19c9 | 1217 | /* Can't register until after driver model init */ |
95026658 | 1218 | if (WARN_ON(!is_registered)) { |
35fc37f8 JD |
1219 | res = -EAGAIN; |
1220 | goto out_list; | |
1221 | } | |
1d0b19c9 | 1222 | |
2236baa7 | 1223 | /* Sanity checks */ |
8ddfe410 | 1224 | if (WARN(!adap->name[0], "i2c adapter has no name")) |
ce0dffaf | 1225 | goto out_list; |
8ddfe410 WS |
1226 | |
1227 | if (!adap->algo) { | |
44239a5a | 1228 | pr_err("adapter '%s': no algo supplied!\n", adap->name); |
ce0dffaf | 1229 | goto out_list; |
2236baa7 JD |
1230 | } |
1231 | ||
d1ed7985 PR |
1232 | if (!adap->lock_ops) |
1233 | adap->lock_ops = &i2c_adapter_lock_ops; | |
8320f495 | 1234 | |
194684e5 | 1235 | rt_mutex_init(&adap->bus_lock); |
6ef91fcc | 1236 | rt_mutex_init(&adap->mux_lock); |
dafc50d1 | 1237 | mutex_init(&adap->userspace_clients_lock); |
6629dcff | 1238 | INIT_LIST_HEAD(&adap->userspace_clients); |
1da177e4 | 1239 | |
8fcfef6e JD |
1240 | /* Set default timeout to 1 second if not already set */ |
1241 | if (adap->timeout == 0) | |
1242 | adap->timeout = HZ; | |
1243 | ||
4d5538f5 BT |
1244 | /* register soft irqs for Host Notify */ |
1245 | res = i2c_setup_host_notify_irq_domain(adap); | |
1246 | if (res) { | |
1247 | pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n", | |
1248 | adap->name, res); | |
1249 | goto out_list; | |
1250 | } | |
1251 | ||
27d9c183 | 1252 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
1253 | adap->dev.bus = &i2c_bus_type; |
1254 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 | 1255 | res = device_register(&adap->dev); |
8ddfe410 | 1256 | if (res) { |
44239a5a | 1257 | pr_err("adapter '%s': can't register device (%d)\n", adap->name, res); |
b119c6c9 | 1258 | goto out_list; |
8ddfe410 | 1259 | } |
1da177e4 | 1260 | |
f8756c67 PR |
1261 | res = of_i2c_setup_smbus_alert(adap); |
1262 | if (res) | |
1263 | goto out_reg; | |
1264 | ||
b6d7b3d1 JD |
1265 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
1266 | ||
6ada5c1e | 1267 | pm_runtime_no_callbacks(&adap->dev); |
04f59143 | 1268 | pm_suspend_ignore_children(&adap->dev, true); |
9f924169 | 1269 | pm_runtime_enable(&adap->dev); |
6ada5c1e | 1270 | |
2bb5095a JD |
1271 | #ifdef CONFIG_I2C_COMPAT |
1272 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
1273 | adap->dev.parent); | |
1274 | if (res) | |
1275 | dev_warn(&adap->dev, | |
1276 | "Failed to create compatibility class link\n"); | |
1277 | #endif | |
1278 | ||
d3b11d83 | 1279 | i2c_init_recovery(adap); |
5f9296ba | 1280 | |
729d6dd5 | 1281 | /* create pre-declared device nodes */ |
687b81d0 | 1282 | of_i2c_register_devices(adap); |
aec809fc JN |
1283 | i2c_acpi_register_devices(adap); |
1284 | i2c_acpi_install_space_handler(adap); | |
687b81d0 | 1285 | |
6e13e641 DB |
1286 | if (adap->nr < __i2c_first_dynamic_bus_num) |
1287 | i2c_scan_static_board_info(adap); | |
1288 | ||
4735c98f | 1289 | /* Notify drivers */ |
35fc37f8 | 1290 | mutex_lock(&core_lock); |
d6703281 | 1291 | bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); |
caada32a | 1292 | mutex_unlock(&core_lock); |
35fc37f8 JD |
1293 | |
1294 | return 0; | |
b119c6c9 | 1295 | |
f8756c67 PR |
1296 | out_reg: |
1297 | init_completion(&adap->dev_released); | |
1298 | device_unregister(&adap->dev); | |
1299 | wait_for_completion(&adap->dev_released); | |
b119c6c9 | 1300 | out_list: |
35fc37f8 | 1301 | mutex_lock(&core_lock); |
b119c6c9 | 1302 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
1303 | mutex_unlock(&core_lock); |
1304 | return res; | |
1da177e4 LT |
1305 | } |
1306 | ||
ee5c2744 DA |
1307 | /** |
1308 | * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 | |
1309 | * @adap: the adapter to register (with adap->nr initialized) | |
1310 | * Context: can sleep | |
1311 | * | |
1312 | * See i2c_add_numbered_adapter() for details. | |
1313 | */ | |
1314 | static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1315 | { | |
84d0b617 | 1316 | int id; |
ee5c2744 DA |
1317 | |
1318 | mutex_lock(&core_lock); | |
84d0b617 | 1319 | id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL); |
ee5c2744 | 1320 | mutex_unlock(&core_lock); |
84d0b617 | 1321 | if (WARN(id < 0, "couldn't get idr")) |
ee5c2744 DA |
1322 | return id == -ENOSPC ? -EBUSY : id; |
1323 | ||
1324 | return i2c_register_adapter(adap); | |
1325 | } | |
1326 | ||
6e13e641 DB |
1327 | /** |
1328 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
1329 | * @adapter: the adapter to add | |
d64f73be | 1330 | * Context: can sleep |
6e13e641 DB |
1331 | * |
1332 | * This routine is used to declare an I2C adapter when its bus number | |
ee5c2744 DA |
1333 | * doesn't matter or when its bus number is specified by an dt alias. |
1334 | * Examples of bases when the bus number doesn't matter: I2C adapters | |
1335 | * dynamically added by USB links or PCI plugin cards. | |
6e13e641 DB |
1336 | * |
1337 | * When this returns zero, a new bus number was allocated and stored | |
1338 | * in adap->nr, and the specified adapter became available for clients. | |
1339 | * Otherwise, a negative errno value is returned. | |
1340 | */ | |
1341 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
1342 | { | |
ee5c2744 | 1343 | struct device *dev = &adapter->dev; |
4ae42b0f | 1344 | int id; |
6e13e641 | 1345 | |
ee5c2744 DA |
1346 | if (dev->of_node) { |
1347 | id = of_alias_get_id(dev->of_node, "i2c"); | |
1348 | if (id >= 0) { | |
1349 | adapter->nr = id; | |
1350 | return __i2c_add_numbered_adapter(adapter); | |
1351 | } | |
1352 | } | |
1353 | ||
caada32a | 1354 | mutex_lock(&core_lock); |
4ae42b0f TH |
1355 | id = idr_alloc(&i2c_adapter_idr, adapter, |
1356 | __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); | |
caada32a | 1357 | mutex_unlock(&core_lock); |
84d0b617 | 1358 | if (WARN(id < 0, "couldn't get idr")) |
4ae42b0f | 1359 | return id; |
6e13e641 DB |
1360 | |
1361 | adapter->nr = id; | |
4ae42b0f | 1362 | |
6e13e641 DB |
1363 | return i2c_register_adapter(adapter); |
1364 | } | |
1365 | EXPORT_SYMBOL(i2c_add_adapter); | |
1366 | ||
1367 | /** | |
1368 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
1369 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 1370 | * Context: can sleep |
6e13e641 DB |
1371 | * |
1372 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
1373 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
1374 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
1375 | * is used to properly configure I2C devices. |
1376 | * | |
488bf314 GL |
1377 | * If the requested bus number is set to -1, then this function will behave |
1378 | * identically to i2c_add_adapter, and will dynamically assign a bus number. | |
1379 | * | |
6e13e641 DB |
1380 | * If no devices have pre-been declared for this bus, then be sure to |
1381 | * register the adapter before any dynamically allocated ones. Otherwise | |
1382 | * the required bus ID may not be available. | |
1383 | * | |
1384 | * When this returns zero, the specified adapter became available for | |
1385 | * clients using the bus number provided in adap->nr. Also, the table | |
1386 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
1387 | * and the appropriate driver model device nodes are created. Otherwise, a | |
1388 | * negative errno value is returned. | |
1389 | */ | |
1390 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1391 | { | |
488bf314 GL |
1392 | if (adap->nr == -1) /* -1 means dynamically assign bus id */ |
1393 | return i2c_add_adapter(adap); | |
6e13e641 | 1394 | |
ee5c2744 | 1395 | return __i2c_add_numbered_adapter(adap); |
6e13e641 DB |
1396 | } |
1397 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
1398 | ||
19baba4c | 1399 | static void i2c_do_del_adapter(struct i2c_driver *driver, |
69b0089a | 1400 | struct i2c_adapter *adapter) |
026526f5 | 1401 | { |
4735c98f | 1402 | struct i2c_client *client, *_n; |
026526f5 | 1403 | |
acec211c JD |
1404 | /* Remove the devices we created ourselves as the result of hardware |
1405 | * probing (using a driver's detect method) */ | |
4735c98f JD |
1406 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
1407 | if (client->adapter == adapter) { | |
1408 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
1409 | client->name, client->addr); | |
1410 | list_del(&client->detected); | |
1411 | i2c_unregister_device(client); | |
1412 | } | |
1413 | } | |
026526f5 JD |
1414 | } |
1415 | ||
e549c2b5 | 1416 | static int __unregister_client(struct device *dev, void *dummy) |
5219bf88 JD |
1417 | { |
1418 | struct i2c_client *client = i2c_verify_client(dev); | |
1419 | if (client && strcmp(client->name, "dummy")) | |
1420 | i2c_unregister_device(client); | |
1421 | return 0; | |
1422 | } | |
1423 | ||
1424 | static int __unregister_dummy(struct device *dev, void *dummy) | |
e549c2b5 JD |
1425 | { |
1426 | struct i2c_client *client = i2c_verify_client(dev); | |
7b43dd19 | 1427 | i2c_unregister_device(client); |
e549c2b5 JD |
1428 | return 0; |
1429 | } | |
1430 | ||
69b0089a JD |
1431 | static int __process_removed_adapter(struct device_driver *d, void *data) |
1432 | { | |
19baba4c LPC |
1433 | i2c_do_del_adapter(to_i2c_driver(d), data); |
1434 | return 0; | |
69b0089a JD |
1435 | } |
1436 | ||
d64f73be DB |
1437 | /** |
1438 | * i2c_del_adapter - unregister I2C adapter | |
1439 | * @adap: the adapter being unregistered | |
1440 | * Context: can sleep | |
1441 | * | |
1442 | * This unregisters an I2C adapter which was previously registered | |
1443 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
1444 | */ | |
71546300 | 1445 | void i2c_del_adapter(struct i2c_adapter *adap) |
1da177e4 | 1446 | { |
35fc37f8 | 1447 | struct i2c_adapter *found; |
bbd2d9c9 | 1448 | struct i2c_client *client, *next; |
1da177e4 LT |
1449 | |
1450 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
1451 | mutex_lock(&core_lock); |
1452 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
1453 | mutex_unlock(&core_lock); | |
1454 | if (found != adap) { | |
44239a5a | 1455 | pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name); |
71546300 | 1456 | return; |
1da177e4 LT |
1457 | } |
1458 | ||
aec809fc | 1459 | i2c_acpi_remove_space_handler(adap); |
026526f5 | 1460 | /* Tell drivers about this removal */ |
35fc37f8 | 1461 | mutex_lock(&core_lock); |
19baba4c | 1462 | bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 1463 | __process_removed_adapter); |
35fc37f8 | 1464 | mutex_unlock(&core_lock); |
1da177e4 | 1465 | |
bbd2d9c9 | 1466 | /* Remove devices instantiated from sysfs */ |
390946b1 JD |
1467 | mutex_lock_nested(&adap->userspace_clients_lock, |
1468 | i2c_adapter_depth(adap)); | |
6629dcff JD |
1469 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1470 | detected) { | |
1471 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, | |
1472 | client->addr); | |
1473 | list_del(&client->detected); | |
1474 | i2c_unregister_device(client); | |
bbd2d9c9 | 1475 | } |
dafc50d1 | 1476 | mutex_unlock(&adap->userspace_clients_lock); |
bbd2d9c9 | 1477 | |
e549c2b5 | 1478 | /* Detach any active clients. This can't fail, thus we do not |
5219bf88 JD |
1479 | * check the returned value. This is a two-pass process, because |
1480 | * we can't remove the dummy devices during the first pass: they | |
1481 | * could have been instantiated by real devices wishing to clean | |
1482 | * them up properly, so we give them a chance to do that first. */ | |
19baba4c LPC |
1483 | device_for_each_child(&adap->dev, NULL, __unregister_client); |
1484 | device_for_each_child(&adap->dev, NULL, __unregister_dummy); | |
1da177e4 | 1485 | |
2bb5095a JD |
1486 | #ifdef CONFIG_I2C_COMPAT |
1487 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
1488 | adap->dev.parent); | |
1489 | #endif | |
1490 | ||
c5567521 TLSC |
1491 | /* device name is gone after device_unregister */ |
1492 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); | |
1493 | ||
9f924169 WS |
1494 | pm_runtime_disable(&adap->dev); |
1495 | ||
4d5538f5 BT |
1496 | i2c_host_notify_irq_teardown(adap); |
1497 | ||
26680ee2 WS |
1498 | /* wait until all references to the device are gone |
1499 | * | |
1500 | * FIXME: This is old code and should ideally be replaced by an | |
1501 | * alternative which results in decoupling the lifetime of the struct | |
1502 | * device from the i2c_adapter, like spi or netdev do. Any solution | |
95cc1e3d | 1503 | * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled! |
26680ee2 | 1504 | */ |
1da177e4 | 1505 | init_completion(&adap->dev_released); |
1da177e4 | 1506 | device_unregister(&adap->dev); |
1da177e4 | 1507 | wait_for_completion(&adap->dev_released); |
1da177e4 | 1508 | |
6e13e641 | 1509 | /* free bus id */ |
35fc37f8 | 1510 | mutex_lock(&core_lock); |
1da177e4 | 1511 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 1512 | mutex_unlock(&core_lock); |
1da177e4 | 1513 | |
bd4bc3db JD |
1514 | /* Clear the device structure in case this adapter is ever going to be |
1515 | added again */ | |
1516 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
1da177e4 | 1517 | } |
c0564606 | 1518 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 | 1519 | |
54177ccf WS |
1520 | /** |
1521 | * i2c_parse_fw_timings - get I2C related timing parameters from firmware | |
1522 | * @dev: The device to scan for I2C timing properties | |
1523 | * @t: the i2c_timings struct to be filled with values | |
1524 | * @use_defaults: bool to use sane defaults derived from the I2C specification | |
1525 | * when properties are not found, otherwise use 0 | |
1526 | * | |
1527 | * Scan the device for the generic I2C properties describing timing parameters | |
1528 | * for the signal and fill the given struct with the results. If a property was | |
1529 | * not found and use_defaults was true, then maximum timings are assumed which | |
1530 | * are derived from the I2C specification. If use_defaults is not used, the | |
1531 | * results will be 0, so drivers can apply their own defaults later. The latter | |
1532 | * is mainly intended for avoiding regressions of existing drivers which want | |
1533 | * to switch to this function. New drivers almost always should use the defaults. | |
1534 | */ | |
1535 | ||
1536 | void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults) | |
1537 | { | |
1538 | int ret; | |
1539 | ||
1540 | memset(t, 0, sizeof(*t)); | |
1541 | ||
1542 | ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz); | |
1543 | if (ret && use_defaults) | |
1544 | t->bus_freq_hz = 100000; | |
1545 | ||
1546 | ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns); | |
1547 | if (ret && use_defaults) { | |
1548 | if (t->bus_freq_hz <= 100000) | |
1549 | t->scl_rise_ns = 1000; | |
1550 | else if (t->bus_freq_hz <= 400000) | |
1551 | t->scl_rise_ns = 300; | |
1552 | else | |
1553 | t->scl_rise_ns = 120; | |
1554 | } | |
1555 | ||
1556 | ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns); | |
1557 | if (ret && use_defaults) { | |
1558 | if (t->bus_freq_hz <= 400000) | |
1559 | t->scl_fall_ns = 300; | |
1560 | else | |
1561 | t->scl_fall_ns = 120; | |
1562 | } | |
1563 | ||
1564 | device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns); | |
1565 | ||
1566 | ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns); | |
1567 | if (ret && use_defaults) | |
1568 | t->sda_fall_ns = t->scl_fall_ns; | |
4717be73 AS |
1569 | |
1570 | device_property_read_u32(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns); | |
54177ccf WS |
1571 | } |
1572 | EXPORT_SYMBOL_GPL(i2c_parse_fw_timings); | |
1573 | ||
7b4fbc50 DB |
1574 | /* ------------------------------------------------------------------------- */ |
1575 | ||
7ae31482 JD |
1576 | int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) |
1577 | { | |
1578 | int res; | |
1579 | ||
1580 | mutex_lock(&core_lock); | |
1581 | res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); | |
1582 | mutex_unlock(&core_lock); | |
1583 | ||
1584 | return res; | |
1585 | } | |
1586 | EXPORT_SYMBOL_GPL(i2c_for_each_dev); | |
1587 | ||
69b0089a | 1588 | static int __process_new_driver(struct device *dev, void *data) |
7f101a97 | 1589 | { |
4f8cf824 JD |
1590 | if (dev->type != &i2c_adapter_type) |
1591 | return 0; | |
69b0089a | 1592 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
7f101a97 DY |
1593 | } |
1594 | ||
7b4fbc50 DB |
1595 | /* |
1596 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 1597 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
1598 | */ |
1599 | ||
de59cf9e | 1600 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 1601 | { |
7eebcb7c | 1602 | int res; |
1da177e4 | 1603 | |
1d0b19c9 | 1604 | /* Can't register until after driver model init */ |
95026658 | 1605 | if (WARN_ON(!is_registered)) |
1d0b19c9 DB |
1606 | return -EAGAIN; |
1607 | ||
1da177e4 | 1608 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 1609 | driver->driver.owner = owner; |
1da177e4 | 1610 | driver->driver.bus = &i2c_bus_type; |
147b36d5 | 1611 | INIT_LIST_HEAD(&driver->clients); |
1da177e4 | 1612 | |
729d6dd5 | 1613 | /* When registration returns, the driver core |
6e13e641 DB |
1614 | * will have called probe() for all matching-but-unbound devices. |
1615 | */ | |
1da177e4 LT |
1616 | res = driver_register(&driver->driver); |
1617 | if (res) | |
7eebcb7c | 1618 | return res; |
438d6c2c | 1619 | |
44239a5a | 1620 | pr_debug("driver [%s] registered\n", driver->driver.name); |
1da177e4 | 1621 | |
4735c98f | 1622 | /* Walk the adapters that are already present */ |
7ae31482 | 1623 | i2c_for_each_dev(driver, __process_new_driver); |
35fc37f8 | 1624 | |
7f101a97 DY |
1625 | return 0; |
1626 | } | |
1627 | EXPORT_SYMBOL(i2c_register_driver); | |
1628 | ||
69b0089a | 1629 | static int __process_removed_driver(struct device *dev, void *data) |
7f101a97 | 1630 | { |
19baba4c LPC |
1631 | if (dev->type == &i2c_adapter_type) |
1632 | i2c_do_del_adapter(data, to_i2c_adapter(dev)); | |
1633 | return 0; | |
1da177e4 LT |
1634 | } |
1635 | ||
a1d9e6e4 DB |
1636 | /** |
1637 | * i2c_del_driver - unregister I2C driver | |
1638 | * @driver: the driver being unregistered | |
d64f73be | 1639 | * Context: can sleep |
a1d9e6e4 | 1640 | */ |
b3e82096 | 1641 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 1642 | { |
7ae31482 | 1643 | i2c_for_each_dev(driver, __process_removed_driver); |
1da177e4 LT |
1644 | |
1645 | driver_unregister(&driver->driver); | |
44239a5a | 1646 | pr_debug("driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 1647 | } |
c0564606 | 1648 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 1649 | |
7b4fbc50 DB |
1650 | /* ------------------------------------------------------------------------- */ |
1651 | ||
e48d3319 JD |
1652 | /** |
1653 | * i2c_use_client - increments the reference count of the i2c client structure | |
1654 | * @client: the client being referenced | |
1655 | * | |
1656 | * Each live reference to a client should be refcounted. The driver model does | |
1657 | * that automatically as part of driver binding, so that most drivers don't | |
1658 | * need to do this explicitly: they hold a reference until they're unbound | |
1659 | * from the device. | |
1660 | * | |
1661 | * A pointer to the client with the incremented reference counter is returned. | |
1662 | */ | |
1663 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 1664 | { |
6ea438ec DB |
1665 | if (client && get_device(&client->dev)) |
1666 | return client; | |
1667 | return NULL; | |
1da177e4 | 1668 | } |
c0564606 | 1669 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 1670 | |
e48d3319 JD |
1671 | /** |
1672 | * i2c_release_client - release a use of the i2c client structure | |
1673 | * @client: the client being no longer referenced | |
1674 | * | |
1675 | * Must be called when a user of a client is finished with it. | |
1676 | */ | |
1677 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 1678 | { |
6ea438ec DB |
1679 | if (client) |
1680 | put_device(&client->dev); | |
1da177e4 | 1681 | } |
c0564606 | 1682 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 1683 | |
9b766b81 DB |
1684 | struct i2c_cmd_arg { |
1685 | unsigned cmd; | |
1686 | void *arg; | |
1687 | }; | |
1688 | ||
1689 | static int i2c_cmd(struct device *dev, void *_arg) | |
1690 | { | |
1691 | struct i2c_client *client = i2c_verify_client(dev); | |
1692 | struct i2c_cmd_arg *arg = _arg; | |
0acc2b32 LPC |
1693 | struct i2c_driver *driver; |
1694 | ||
1695 | if (!client || !client->dev.driver) | |
1696 | return 0; | |
9b766b81 | 1697 | |
0acc2b32 LPC |
1698 | driver = to_i2c_driver(client->dev.driver); |
1699 | if (driver->command) | |
1700 | driver->command(client, arg->cmd, arg->arg); | |
9b766b81 DB |
1701 | return 0; |
1702 | } | |
1703 | ||
1da177e4 LT |
1704 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
1705 | { | |
9b766b81 | 1706 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 1707 | |
9b766b81 DB |
1708 | cmd_arg.cmd = cmd; |
1709 | cmd_arg.arg = arg; | |
1710 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 1711 | } |
c0564606 | 1712 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
1713 | |
1714 | static int __init i2c_init(void) | |
1715 | { | |
1716 | int retval; | |
1717 | ||
03bde7c3 WS |
1718 | retval = of_alias_get_highest_id("i2c"); |
1719 | ||
1720 | down_write(&__i2c_board_lock); | |
1721 | if (retval >= __i2c_first_dynamic_bus_num) | |
1722 | __i2c_first_dynamic_bus_num = retval + 1; | |
1723 | up_write(&__i2c_board_lock); | |
1724 | ||
1da177e4 | 1725 | retval = bus_register(&i2c_bus_type); |
1da177e4 LT |
1726 | if (retval) |
1727 | return retval; | |
b980a26d WS |
1728 | |
1729 | is_registered = true; | |
1730 | ||
2bb5095a JD |
1731 | #ifdef CONFIG_I2C_COMPAT |
1732 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
1733 | if (!i2c_adapter_compat_class) { | |
1734 | retval = -ENOMEM; | |
1735 | goto bus_err; | |
1736 | } | |
1737 | #endif | |
e9f1373b DB |
1738 | retval = i2c_add_driver(&dummy_driver); |
1739 | if (retval) | |
2bb5095a | 1740 | goto class_err; |
ea7513bb PA |
1741 | |
1742 | if (IS_ENABLED(CONFIG_OF_DYNAMIC)) | |
1743 | WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)); | |
525e6fab OP |
1744 | if (IS_ENABLED(CONFIG_ACPI)) |
1745 | WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier)); | |
ea7513bb | 1746 | |
e9f1373b DB |
1747 | return 0; |
1748 | ||
2bb5095a JD |
1749 | class_err: |
1750 | #ifdef CONFIG_I2C_COMPAT | |
1751 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 1752 | bus_err: |
2bb5095a | 1753 | #endif |
b980a26d | 1754 | is_registered = false; |
e9f1373b DB |
1755 | bus_unregister(&i2c_bus_type); |
1756 | return retval; | |
1da177e4 LT |
1757 | } |
1758 | ||
1759 | static void __exit i2c_exit(void) | |
1760 | { | |
525e6fab OP |
1761 | if (IS_ENABLED(CONFIG_ACPI)) |
1762 | WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier)); | |
ea7513bb PA |
1763 | if (IS_ENABLED(CONFIG_OF_DYNAMIC)) |
1764 | WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier)); | |
e9f1373b | 1765 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
1766 | #ifdef CONFIG_I2C_COMPAT |
1767 | class_compat_unregister(i2c_adapter_compat_class); | |
1768 | #endif | |
1da177e4 | 1769 | bus_unregister(&i2c_bus_type); |
d9a83d62 | 1770 | tracepoint_synchronize_unregister(); |
1da177e4 LT |
1771 | } |
1772 | ||
a10f9e7c DB |
1773 | /* We must initialize early, because some subsystems register i2c drivers |
1774 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1775 | */ | |
1776 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1777 | module_exit(i2c_exit); |
1778 | ||
1779 | /* ---------------------------------------------------- | |
1780 | * the functional interface to the i2c busses. | |
1781 | * ---------------------------------------------------- | |
1782 | */ | |
1783 | ||
b7f62584 WS |
1784 | /* Check if val is exceeding the quirk IFF quirk is non 0 */ |
1785 | #define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk))) | |
1786 | ||
1787 | static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg) | |
1788 | { | |
1789 | dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n", | |
1790 | err_msg, msg->addr, msg->len, | |
1791 | msg->flags & I2C_M_RD ? "read" : "write"); | |
1792 | return -EOPNOTSUPP; | |
1793 | } | |
1794 | ||
1795 | static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
1796 | { | |
1797 | const struct i2c_adapter_quirks *q = adap->quirks; | |
1798 | int max_num = q->max_num_msgs, i; | |
1799 | bool do_len_check = true; | |
1800 | ||
1801 | if (q->flags & I2C_AQ_COMB) { | |
1802 | max_num = 2; | |
1803 | ||
1804 | /* special checks for combined messages */ | |
1805 | if (num == 2) { | |
1806 | if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD) | |
1807 | return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write"); | |
1808 | ||
1809 | if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD)) | |
1810 | return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read"); | |
1811 | ||
1812 | if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr) | |
1813 | return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr"); | |
1814 | ||
1815 | if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len)) | |
1816 | return i2c_quirk_error(adap, &msgs[0], "msg too long"); | |
1817 | ||
1818 | if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len)) | |
1819 | return i2c_quirk_error(adap, &msgs[1], "msg too long"); | |
1820 | ||
1821 | do_len_check = false; | |
1822 | } | |
1823 | } | |
1824 | ||
1825 | if (i2c_quirk_exceeded(num, max_num)) | |
1826 | return i2c_quirk_error(adap, &msgs[0], "too many messages"); | |
1827 | ||
1828 | for (i = 0; i < num; i++) { | |
1829 | u16 len = msgs[i].len; | |
1830 | ||
1831 | if (msgs[i].flags & I2C_M_RD) { | |
1832 | if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len)) | |
1833 | return i2c_quirk_error(adap, &msgs[i], "msg too long"); | |
d9cfe2ce WS |
1834 | |
1835 | if (q->flags & I2C_AQ_NO_ZERO_LEN_READ && len == 0) | |
1836 | return i2c_quirk_error(adap, &msgs[i], "no zero length"); | |
b7f62584 WS |
1837 | } else { |
1838 | if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len)) | |
1839 | return i2c_quirk_error(adap, &msgs[i], "msg too long"); | |
d9cfe2ce WS |
1840 | |
1841 | if (q->flags & I2C_AQ_NO_ZERO_LEN_WRITE && len == 0) | |
1842 | return i2c_quirk_error(adap, &msgs[i], "no zero length"); | |
b7f62584 WS |
1843 | } |
1844 | } | |
1845 | ||
1846 | return 0; | |
1847 | } | |
1848 | ||
b37d2a3a JD |
1849 | /** |
1850 | * __i2c_transfer - unlocked flavor of i2c_transfer | |
1851 | * @adap: Handle to I2C bus | |
1852 | * @msgs: One or more messages to execute before STOP is issued to | |
1853 | * terminate the operation; each message begins with a START. | |
1854 | * @num: Number of messages to be executed. | |
1855 | * | |
1856 | * Returns negative errno, else the number of messages executed. | |
1857 | * | |
1858 | * Adapter lock must be held when calling this function. No debug logging | |
1859 | * takes place. adap->algo->master_xfer existence isn't checked. | |
1860 | */ | |
1861 | int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
1862 | { | |
1863 | unsigned long orig_jiffies; | |
1864 | int ret, try; | |
1865 | ||
1eace834 AB |
1866 | if (WARN_ON(!msgs || num < 1)) |
1867 | return -EINVAL; | |
1868 | ||
b7f62584 WS |
1869 | if (adap->quirks && i2c_check_for_quirks(adap, msgs, num)) |
1870 | return -EOPNOTSUPP; | |
1871 | ||
50888b01 DB |
1872 | /* |
1873 | * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets | |
d9a83d62 DH |
1874 | * enabled. This is an efficient way of keeping the for-loop from |
1875 | * being executed when not needed. | |
1876 | */ | |
50888b01 | 1877 | if (static_branch_unlikely(&i2c_trace_msg_key)) { |
d9a83d62 DH |
1878 | int i; |
1879 | for (i = 0; i < num; i++) | |
1880 | if (msgs[i].flags & I2C_M_RD) | |
1881 | trace_i2c_read(adap, &msgs[i], i); | |
1882 | else | |
1883 | trace_i2c_write(adap, &msgs[i], i); | |
1884 | } | |
1885 | ||
b37d2a3a JD |
1886 | /* Retry automatically on arbitration loss */ |
1887 | orig_jiffies = jiffies; | |
1888 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
1889 | ret = adap->algo->master_xfer(adap, msgs, num); | |
1890 | if (ret != -EAGAIN) | |
1891 | break; | |
1892 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
1893 | break; | |
1894 | } | |
1895 | ||
50888b01 | 1896 | if (static_branch_unlikely(&i2c_trace_msg_key)) { |
d9a83d62 DH |
1897 | int i; |
1898 | for (i = 0; i < ret; i++) | |
1899 | if (msgs[i].flags & I2C_M_RD) | |
1900 | trace_i2c_reply(adap, &msgs[i], i); | |
4a3f7691 | 1901 | trace_i2c_result(adap, num, ret); |
d9a83d62 DH |
1902 | } |
1903 | ||
b37d2a3a JD |
1904 | return ret; |
1905 | } | |
1906 | EXPORT_SYMBOL(__i2c_transfer); | |
1907 | ||
a1cdedac DB |
1908 | /** |
1909 | * i2c_transfer - execute a single or combined I2C message | |
1910 | * @adap: Handle to I2C bus | |
1911 | * @msgs: One or more messages to execute before STOP is issued to | |
1912 | * terminate the operation; each message begins with a START. | |
1913 | * @num: Number of messages to be executed. | |
1914 | * | |
1915 | * Returns negative errno, else the number of messages executed. | |
1916 | * | |
1917 | * Note that there is no requirement that each message be sent to | |
1918 | * the same slave address, although that is the most common model. | |
1919 | */ | |
09b8ce0a | 1920 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 1921 | { |
b37d2a3a | 1922 | int ret; |
1da177e4 | 1923 | |
cc52612e WS |
1924 | if (!adap->algo->master_xfer) { |
1925 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
1926 | return -EOPNOTSUPP; | |
1927 | } | |
1928 | ||
a1cdedac DB |
1929 | /* REVISIT the fault reporting model here is weak: |
1930 | * | |
1931 | * - When we get an error after receiving N bytes from a slave, | |
1932 | * there is no way to report "N". | |
1933 | * | |
1934 | * - When we get a NAK after transmitting N bytes to a slave, | |
1935 | * there is no way to report "N" ... or to let the master | |
1936 | * continue executing the rest of this combined message, if | |
1937 | * that's the appropriate response. | |
1938 | * | |
1939 | * - When for example "num" is two and we successfully complete | |
1940 | * the first message but get an error part way through the | |
1941 | * second, it's unclear whether that should be reported as | |
1942 | * one (discarding status on the second message) or errno | |
1943 | * (discarding status on the first one). | |
1944 | */ | |
cc52612e WS |
1945 | if (in_atomic() || irqs_disabled()) { |
1946 | ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT); | |
1947 | if (!ret) | |
1948 | /* I2C activity is ongoing. */ | |
1949 | return -EAGAIN; | |
1da177e4 | 1950 | } else { |
cc52612e | 1951 | i2c_lock_bus(adap, I2C_LOCK_SEGMENT); |
1da177e4 | 1952 | } |
cc52612e WS |
1953 | |
1954 | ret = __i2c_transfer(adap, msgs, num); | |
1955 | i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); | |
1956 | ||
1957 | return ret; | |
1da177e4 | 1958 | } |
c0564606 | 1959 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1960 | |
a1cdedac | 1961 | /** |
8a91732b WS |
1962 | * i2c_transfer_buffer_flags - issue a single I2C message transferring data |
1963 | * to/from a buffer | |
a1cdedac | 1964 | * @client: Handle to slave device |
8a91732b WS |
1965 | * @buf: Where the data is stored |
1966 | * @count: How many bytes to transfer, must be less than 64k since msg.len is u16 | |
1967 | * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads | |
a1cdedac | 1968 | * |
8a91732b | 1969 | * Returns negative errno, or else the number of bytes transferred. |
a1cdedac | 1970 | */ |
8a91732b WS |
1971 | int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, |
1972 | int count, u16 flags) | |
1da177e4 | 1973 | { |
1da177e4 | 1974 | int ret; |
8a91732b WS |
1975 | struct i2c_msg msg = { |
1976 | .addr = client->addr, | |
1977 | .flags = flags | (client->flags & I2C_M_TEN), | |
1978 | .len = count, | |
1979 | .buf = buf, | |
1980 | }; | |
815f55f2 | 1981 | |
8a91732b | 1982 | ret = i2c_transfer(client->adapter, &msg, 1); |
815f55f2 | 1983 | |
834aa6f3 | 1984 | /* |
8a91732b WS |
1985 | * If everything went ok (i.e. 1 msg transferred), return #bytes |
1986 | * transferred, else error code. | |
834aa6f3 | 1987 | */ |
815f55f2 | 1988 | return (ret == 1) ? count : ret; |
1da177e4 | 1989 | } |
8a91732b | 1990 | EXPORT_SYMBOL(i2c_transfer_buffer_flags); |
1da177e4 | 1991 | |
dde67eb1 PR |
1992 | /** |
1993 | * i2c_get_device_id - get manufacturer, part id and die revision of a device | |
1994 | * @client: The device to query | |
1995 | * @id: The queried information | |
1996 | * | |
1997 | * Returns negative errno on error, zero on success. | |
1998 | */ | |
1999 | int i2c_get_device_id(const struct i2c_client *client, | |
2000 | struct i2c_device_identity *id) | |
2001 | { | |
2002 | struct i2c_adapter *adap = client->adapter; | |
2003 | union i2c_smbus_data raw_id; | |
2004 | int ret; | |
2005 | ||
2006 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) | |
2007 | return -EOPNOTSUPP; | |
2008 | ||
2009 | raw_id.block[0] = 3; | |
2010 | ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0, | |
2011 | I2C_SMBUS_READ, client->addr << 1, | |
2012 | I2C_SMBUS_I2C_BLOCK_DATA, &raw_id); | |
2013 | if (ret) | |
2014 | return ret; | |
2015 | ||
2016 | id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4); | |
2017 | id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3); | |
2018 | id->die_revision = raw_id.block[3] & 0x7; | |
2019 | return 0; | |
2020 | } | |
2021 | EXPORT_SYMBOL_GPL(i2c_get_device_id); | |
2022 | ||
1da177e4 LT |
2023 | /* ---------------------------------------------------- |
2024 | * the i2c address scanning function | |
2025 | * Will not work for 10-bit addresses! | |
2026 | * ---------------------------------------------------- | |
2027 | */ | |
1da177e4 | 2028 | |
63e4e802 JD |
2029 | /* |
2030 | * Legacy default probe function, mostly relevant for SMBus. The default | |
2031 | * probe method is a quick write, but it is known to corrupt the 24RF08 | |
2032 | * EEPROMs due to a state machine bug, and could also irreversibly | |
2033 | * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, | |
2034 | * we use a short byte read instead. Also, some bus drivers don't implement | |
2035 | * quick write, so we fallback to a byte read in that case too. | |
2036 | * On x86, there is another special case for FSC hardware monitoring chips, | |
2037 | * which want regular byte reads (address 0x73.) Fortunately, these are the | |
2038 | * only known chips using this I2C address on PC hardware. | |
2039 | * Returns 1 if probe succeeded, 0 if not. | |
2040 | */ | |
2041 | static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) | |
2042 | { | |
2043 | int err; | |
2044 | union i2c_smbus_data dummy; | |
2045 | ||
2046 | #ifdef CONFIG_X86 | |
2047 | if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) | |
2048 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) | |
2049 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
2050 | I2C_SMBUS_BYTE_DATA, &dummy); | |
2051 | else | |
2052 | #endif | |
8031d79b JD |
2053 | if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) |
2054 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) | |
63e4e802 JD |
2055 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, |
2056 | I2C_SMBUS_QUICK, NULL); | |
8031d79b JD |
2057 | else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) |
2058 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
2059 | I2C_SMBUS_BYTE, &dummy); | |
2060 | else { | |
d63a9e85 AL |
2061 | dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", |
2062 | addr); | |
8031d79b JD |
2063 | err = -EOPNOTSUPP; |
2064 | } | |
63e4e802 JD |
2065 | |
2066 | return err >= 0; | |
2067 | } | |
2068 | ||
ccfbbd08 | 2069 | static int i2c_detect_address(struct i2c_client *temp_client, |
4735c98f JD |
2070 | struct i2c_driver *driver) |
2071 | { | |
2072 | struct i2c_board_info info; | |
2073 | struct i2c_adapter *adapter = temp_client->adapter; | |
2074 | int addr = temp_client->addr; | |
2075 | int err; | |
2076 | ||
2077 | /* Make sure the address is valid */ | |
66be6056 | 2078 | err = i2c_check_7bit_addr_validity_strict(addr); |
656b8761 | 2079 | if (err) { |
4735c98f JD |
2080 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
2081 | addr); | |
656b8761 | 2082 | return err; |
4735c98f JD |
2083 | } |
2084 | ||
9bccc70a | 2085 | /* Skip if already in use (7 bit, no need to encode flags) */ |
3b5f794b | 2086 | if (i2c_check_addr_busy(adapter, addr)) |
4735c98f JD |
2087 | return 0; |
2088 | ||
ccfbbd08 | 2089 | /* Make sure there is something at this address */ |
63e4e802 JD |
2090 | if (!i2c_default_probe(adapter, addr)) |
2091 | return 0; | |
4735c98f JD |
2092 | |
2093 | /* Finally call the custom detection function */ | |
2094 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
2095 | info.addr = addr; | |
310ec792 | 2096 | err = driver->detect(temp_client, &info); |
4735c98f JD |
2097 | if (err) { |
2098 | /* -ENODEV is returned if the detection fails. We catch it | |
2099 | here as this isn't an error. */ | |
2100 | return err == -ENODEV ? 0 : err; | |
2101 | } | |
2102 | ||
2103 | /* Consistency check */ | |
2104 | if (info.type[0] == '\0') { | |
b93d3d37 AS |
2105 | dev_err(&adapter->dev, |
2106 | "%s detection function provided no name for 0x%x\n", | |
2107 | driver->driver.name, addr); | |
4735c98f JD |
2108 | } else { |
2109 | struct i2c_client *client; | |
2110 | ||
2111 | /* Detection succeeded, instantiate the device */ | |
0c176170 WS |
2112 | if (adapter->class & I2C_CLASS_DEPRECATED) |
2113 | dev_warn(&adapter->dev, | |
2114 | "This adapter will soon drop class based instantiation of devices. " | |
2115 | "Please make sure client 0x%02x gets instantiated by other means. " | |
2116 | "Check 'Documentation/i2c/instantiating-devices' for details.\n", | |
2117 | info.addr); | |
2118 | ||
4735c98f JD |
2119 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", |
2120 | info.type, info.addr); | |
2121 | client = i2c_new_device(adapter, &info); | |
2122 | if (client) | |
2123 | list_add_tail(&client->detected, &driver->clients); | |
2124 | else | |
2125 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
2126 | info.type, info.addr); | |
2127 | } | |
2128 | return 0; | |
2129 | } | |
2130 | ||
2131 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
2132 | { | |
c3813d6a | 2133 | const unsigned short *address_list; |
4735c98f JD |
2134 | struct i2c_client *temp_client; |
2135 | int i, err = 0; | |
2136 | int adap_id = i2c_adapter_id(adapter); | |
2137 | ||
c3813d6a JD |
2138 | address_list = driver->address_list; |
2139 | if (!driver->detect || !address_list) | |
4735c98f JD |
2140 | return 0; |
2141 | ||
45552272 WS |
2142 | /* Warn that the adapter lost class based instantiation */ |
2143 | if (adapter->class == I2C_CLASS_DEPRECATED) { | |
2144 | dev_dbg(&adapter->dev, | |
b93d3d37 AS |
2145 | "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. " |
2146 | "If you need it, check 'Documentation/i2c/instantiating-devices' for alternatives.\n", | |
45552272 WS |
2147 | driver->driver.name); |
2148 | return 0; | |
2149 | } | |
2150 | ||
51b54ba9 JD |
2151 | /* Stop here if the classes do not match */ |
2152 | if (!(adapter->class & driver->class)) | |
2153 | return 0; | |
2154 | ||
4735c98f JD |
2155 | /* Set up a temporary client to help detect callback */ |
2156 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
2157 | if (!temp_client) | |
2158 | return -ENOMEM; | |
2159 | temp_client->adapter = adapter; | |
2160 | ||
c3813d6a | 2161 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
b93d3d37 AS |
2162 | dev_dbg(&adapter->dev, |
2163 | "found normal entry for adapter %d, addr 0x%02x\n", | |
2164 | adap_id, address_list[i]); | |
c3813d6a | 2165 | temp_client->addr = address_list[i]; |
ccfbbd08 | 2166 | err = i2c_detect_address(temp_client, driver); |
51b54ba9 JD |
2167 | if (unlikely(err)) |
2168 | break; | |
4735c98f JD |
2169 | } |
2170 | ||
4735c98f JD |
2171 | kfree(temp_client); |
2172 | return err; | |
2173 | } | |
2174 | ||
d44f19d5 JD |
2175 | int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) |
2176 | { | |
2177 | return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
2178 | I2C_SMBUS_QUICK, NULL) >= 0; | |
2179 | } | |
2180 | EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); | |
2181 | ||
12b5053a JD |
2182 | struct i2c_client * |
2183 | i2c_new_probed_device(struct i2c_adapter *adap, | |
2184 | struct i2c_board_info *info, | |
9a94241a JD |
2185 | unsigned short const *addr_list, |
2186 | int (*probe)(struct i2c_adapter *, unsigned short addr)) | |
12b5053a JD |
2187 | { |
2188 | int i; | |
2189 | ||
8031d79b | 2190 | if (!probe) |
9a94241a | 2191 | probe = i2c_default_probe; |
12b5053a | 2192 | |
12b5053a JD |
2193 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
2194 | /* Check address validity */ | |
66be6056 | 2195 | if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) { |
b93d3d37 AS |
2196 | dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n", |
2197 | addr_list[i]); | |
12b5053a JD |
2198 | continue; |
2199 | } | |
2200 | ||
9bccc70a | 2201 | /* Check address availability (7 bit, no need to encode flags) */ |
3b5f794b | 2202 | if (i2c_check_addr_busy(adap, addr_list[i])) { |
b93d3d37 AS |
2203 | dev_dbg(&adap->dev, |
2204 | "Address 0x%02x already in use, not probing\n", | |
2205 | addr_list[i]); | |
12b5053a JD |
2206 | continue; |
2207 | } | |
2208 | ||
63e4e802 | 2209 | /* Test address responsiveness */ |
9a94241a | 2210 | if (probe(adap, addr_list[i])) |
63e4e802 | 2211 | break; |
12b5053a | 2212 | } |
12b5053a JD |
2213 | |
2214 | if (addr_list[i] == I2C_CLIENT_END) { | |
2215 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
2216 | return NULL; | |
2217 | } | |
2218 | ||
2219 | info->addr = addr_list[i]; | |
2220 | return i2c_new_device(adap, info); | |
2221 | } | |
2222 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
2223 | ||
d735b34d | 2224 | struct i2c_adapter *i2c_get_adapter(int nr) |
1da177e4 | 2225 | { |
1da177e4 | 2226 | struct i2c_adapter *adapter; |
438d6c2c | 2227 | |
caada32a | 2228 | mutex_lock(&core_lock); |
d735b34d | 2229 | adapter = idr_find(&i2c_adapter_idr, nr); |
611e12ea VZ |
2230 | if (!adapter) |
2231 | goto exit; | |
2232 | ||
2233 | if (try_module_get(adapter->owner)) | |
2234 | get_device(&adapter->dev); | |
2235 | else | |
a0920e10 MH |
2236 | adapter = NULL; |
2237 | ||
611e12ea | 2238 | exit: |
caada32a | 2239 | mutex_unlock(&core_lock); |
a0920e10 | 2240 | return adapter; |
1da177e4 | 2241 | } |
c0564606 | 2242 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
2243 | |
2244 | void i2c_put_adapter(struct i2c_adapter *adap) | |
2245 | { | |
611e12ea VZ |
2246 | if (!adap) |
2247 | return; | |
2248 | ||
2249 | put_device(&adap->dev); | |
2250 | module_put(adap->owner); | |
1da177e4 | 2251 | } |
c0564606 | 2252 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 | 2253 | |
e94bc5d1 WS |
2254 | /** |
2255 | * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg | |
2256 | * @msg: the message to be checked | |
2257 | * @threshold: the minimum number of bytes for which using DMA makes sense | |
2258 | * | |
2259 | * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO. | |
2260 | * Or a valid pointer to be used with DMA. After use, release it by | |
34d1b82c | 2261 | * calling i2c_put_dma_safe_msg_buf(). |
e94bc5d1 WS |
2262 | * |
2263 | * This function must only be called from process context! | |
2264 | */ | |
2265 | u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold) | |
2266 | { | |
2267 | if (msg->len < threshold) | |
2268 | return NULL; | |
2269 | ||
2270 | if (msg->flags & I2C_M_DMA_SAFE) | |
2271 | return msg->buf; | |
2272 | ||
2273 | pr_debug("using bounce buffer for addr=0x%02x, len=%d\n", | |
2274 | msg->addr, msg->len); | |
2275 | ||
2276 | if (msg->flags & I2C_M_RD) | |
2277 | return kzalloc(msg->len, GFP_KERNEL); | |
2278 | else | |
2279 | return kmemdup(msg->buf, msg->len, GFP_KERNEL); | |
2280 | } | |
2281 | EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf); | |
2282 | ||
2283 | /** | |
82fe39a6 | 2284 | * i2c_put_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg |
e94bc5d1 | 2285 | * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL. |
82fe39a6 WS |
2286 | * @msg: the message which the buffer corresponds to |
2287 | * @xferred: bool saying if the message was transferred | |
e94bc5d1 | 2288 | */ |
82fe39a6 | 2289 | void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred) |
e94bc5d1 WS |
2290 | { |
2291 | if (!buf || buf == msg->buf) | |
2292 | return; | |
2293 | ||
82fe39a6 | 2294 | if (xferred && msg->flags & I2C_M_RD) |
e94bc5d1 WS |
2295 | memcpy(msg->buf, buf, msg->len); |
2296 | ||
2297 | kfree(buf); | |
2298 | } | |
82fe39a6 | 2299 | EXPORT_SYMBOL_GPL(i2c_put_dma_safe_msg_buf); |
e94bc5d1 | 2300 | |
1da177e4 LT |
2301 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); |
2302 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
2303 | MODULE_LICENSE("GPL"); |