Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* i2c-core.c - a device driver for the iic-bus interface */ |
2 | /* ------------------------------------------------------------------------- */ | |
3 | /* Copyright (C) 1995-99 Simon G. Vogl | |
4 | ||
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
7 | the Free Software Foundation; either version 2 of the License, or | |
8 | (at your option) any later version. | |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
16 | along with this program; if not, write to the Free Software | |
17 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
18 | /* ------------------------------------------------------------------------- */ | |
19 | ||
96de0e25 | 20 | /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>. |
1da177e4 | 21 | All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl> |
421ef47b JD |
22 | SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and |
23 | Jean Delvare <khali@linux-fr.org> */ | |
1da177e4 | 24 | |
1da177e4 LT |
25 | #include <linux/module.h> |
26 | #include <linux/kernel.h> | |
27 | #include <linux/errno.h> | |
28 | #include <linux/slab.h> | |
29 | #include <linux/i2c.h> | |
30 | #include <linux/init.h> | |
31 | #include <linux/idr.h> | |
b3585e4f | 32 | #include <linux/mutex.h> |
b8d6f45b | 33 | #include <linux/completion.h> |
cea443a8 MR |
34 | #include <linux/hardirq.h> |
35 | #include <linux/irqflags.h> | |
f18c41da | 36 | #include <linux/rwsem.h> |
1da177e4 LT |
37 | #include <asm/uaccess.h> |
38 | ||
9c1600ed DB |
39 | #include "i2c-core.h" |
40 | ||
1da177e4 | 41 | |
99cd8e25 | 42 | /* core_lock protects i2c_adapter_idr, userspace_devices, and guarantees |
35fc37f8 JD |
43 | that device detection, deletion of detected devices, and attach_adapter |
44 | and detach_adapter calls are serialized */ | |
caada32a | 45 | static DEFINE_MUTEX(core_lock); |
1da177e4 | 46 | static DEFINE_IDR(i2c_adapter_idr); |
99cd8e25 | 47 | static LIST_HEAD(userspace_devices); |
1da177e4 | 48 | |
4f8cf824 | 49 | static struct device_type i2c_client_type; |
f8a227e8 | 50 | static int i2c_check_addr(struct i2c_adapter *adapter, int addr); |
4735c98f | 51 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
f37dd80a DB |
52 | |
53 | /* ------------------------------------------------------------------------- */ | |
54 | ||
d2653e92 JD |
55 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
56 | const struct i2c_client *client) | |
57 | { | |
58 | while (id->name[0]) { | |
59 | if (strcmp(client->name, id->name) == 0) | |
60 | return id; | |
61 | id++; | |
62 | } | |
63 | return NULL; | |
64 | } | |
65 | ||
1da177e4 LT |
66 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
67 | { | |
51298d12 JD |
68 | struct i2c_client *client = i2c_verify_client(dev); |
69 | struct i2c_driver *driver; | |
70 | ||
71 | if (!client) | |
72 | return 0; | |
7b4fbc50 | 73 | |
51298d12 | 74 | driver = to_i2c_driver(drv); |
d2653e92 JD |
75 | /* match on an id table if there is one */ |
76 | if (driver->id_table) | |
77 | return i2c_match_id(driver->id_table, client) != NULL; | |
78 | ||
eb8a7908 | 79 | return 0; |
1da177e4 LT |
80 | } |
81 | ||
7b4fbc50 DB |
82 | #ifdef CONFIG_HOTPLUG |
83 | ||
84 | /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ | |
7eff2e7a | 85 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 DB |
86 | { |
87 | struct i2c_client *client = to_i2c_client(dev); | |
7b4fbc50 | 88 | |
eb8a7908 JD |
89 | if (add_uevent_var(env, "MODALIAS=%s%s", |
90 | I2C_MODULE_PREFIX, client->name)) | |
91 | return -ENOMEM; | |
7b4fbc50 DB |
92 | dev_dbg(dev, "uevent\n"); |
93 | return 0; | |
94 | } | |
95 | ||
96 | #else | |
97 | #define i2c_device_uevent NULL | |
98 | #endif /* CONFIG_HOTPLUG */ | |
99 | ||
f37dd80a | 100 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 101 | { |
51298d12 JD |
102 | struct i2c_client *client = i2c_verify_client(dev); |
103 | struct i2c_driver *driver; | |
50c3304a | 104 | int status; |
7b4fbc50 | 105 | |
51298d12 JD |
106 | if (!client) |
107 | return 0; | |
108 | ||
109 | driver = to_i2c_driver(dev->driver); | |
e0457442 | 110 | if (!driver->probe || !driver->id_table) |
7b4fbc50 DB |
111 | return -ENODEV; |
112 | client->driver = driver; | |
ee35425c MP |
113 | if (!device_can_wakeup(&client->dev)) |
114 | device_init_wakeup(&client->dev, | |
115 | client->flags & I2C_CLIENT_WAKE); | |
7b4fbc50 | 116 | dev_dbg(dev, "probe\n"); |
d2653e92 | 117 | |
e0457442 | 118 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
50c3304a HV |
119 | if (status) |
120 | client->driver = NULL; | |
121 | return status; | |
f37dd80a | 122 | } |
1da177e4 | 123 | |
f37dd80a DB |
124 | static int i2c_device_remove(struct device *dev) |
125 | { | |
51298d12 | 126 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 DB |
127 | struct i2c_driver *driver; |
128 | int status; | |
129 | ||
51298d12 | 130 | if (!client || !dev->driver) |
a1d9e6e4 DB |
131 | return 0; |
132 | ||
133 | driver = to_i2c_driver(dev->driver); | |
134 | if (driver->remove) { | |
135 | dev_dbg(dev, "remove\n"); | |
136 | status = driver->remove(client); | |
137 | } else { | |
138 | dev->driver = NULL; | |
139 | status = 0; | |
140 | } | |
141 | if (status == 0) | |
142 | client->driver = NULL; | |
143 | return status; | |
1da177e4 LT |
144 | } |
145 | ||
f37dd80a | 146 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 147 | { |
51298d12 | 148 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
149 | struct i2c_driver *driver; |
150 | ||
51298d12 | 151 | if (!client || !dev->driver) |
f37dd80a DB |
152 | return; |
153 | driver = to_i2c_driver(dev->driver); | |
154 | if (driver->shutdown) | |
51298d12 | 155 | driver->shutdown(client); |
1da177e4 LT |
156 | } |
157 | ||
54067ee2 | 158 | #ifdef CONFIG_SUSPEND |
159 | static int i2c_device_pm_suspend(struct device *dev) | |
160 | { | |
161 | const struct dev_pm_ops *pm; | |
162 | ||
163 | if (!dev->driver) | |
164 | return 0; | |
165 | pm = dev->driver->pm; | |
166 | if (!pm || !pm->suspend) | |
167 | return 0; | |
168 | return pm->suspend(dev); | |
169 | } | |
170 | ||
171 | static int i2c_device_pm_resume(struct device *dev) | |
172 | { | |
173 | const struct dev_pm_ops *pm; | |
174 | ||
175 | if (!dev->driver) | |
176 | return 0; | |
177 | pm = dev->driver->pm; | |
178 | if (!pm || !pm->resume) | |
179 | return 0; | |
180 | return pm->resume(dev); | |
181 | } | |
182 | #else | |
183 | #define i2c_device_pm_suspend NULL | |
184 | #define i2c_device_pm_resume NULL | |
185 | #endif | |
186 | ||
09b8ce0a | 187 | static int i2c_device_suspend(struct device *dev, pm_message_t mesg) |
1da177e4 | 188 | { |
51298d12 | 189 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
190 | struct i2c_driver *driver; |
191 | ||
51298d12 | 192 | if (!client || !dev->driver) |
f37dd80a DB |
193 | return 0; |
194 | driver = to_i2c_driver(dev->driver); | |
195 | if (!driver->suspend) | |
196 | return 0; | |
51298d12 | 197 | return driver->suspend(client, mesg); |
1da177e4 LT |
198 | } |
199 | ||
09b8ce0a | 200 | static int i2c_device_resume(struct device *dev) |
1da177e4 | 201 | { |
51298d12 | 202 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
203 | struct i2c_driver *driver; |
204 | ||
51298d12 | 205 | if (!client || !dev->driver) |
f37dd80a DB |
206 | return 0; |
207 | driver = to_i2c_driver(dev->driver); | |
208 | if (!driver->resume) | |
209 | return 0; | |
51298d12 | 210 | return driver->resume(client); |
1da177e4 LT |
211 | } |
212 | ||
9c1600ed DB |
213 | static void i2c_client_dev_release(struct device *dev) |
214 | { | |
215 | kfree(to_i2c_client(dev)); | |
216 | } | |
217 | ||
09b8ce0a | 218 | static ssize_t |
4f8cf824 | 219 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 220 | { |
4f8cf824 JD |
221 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
222 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 DB |
223 | } |
224 | ||
09b8ce0a ZX |
225 | static ssize_t |
226 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
227 | { |
228 | struct i2c_client *client = to_i2c_client(dev); | |
eb8a7908 | 229 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
230 | } |
231 | ||
4f8cf824 | 232 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
51298d12 JD |
233 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
234 | ||
235 | static struct attribute *i2c_dev_attrs[] = { | |
236 | &dev_attr_name.attr, | |
7b4fbc50 | 237 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
238 | &dev_attr_modalias.attr, |
239 | NULL | |
240 | }; | |
241 | ||
242 | static struct attribute_group i2c_dev_attr_group = { | |
243 | .attrs = i2c_dev_attrs, | |
244 | }; | |
245 | ||
246 | static const struct attribute_group *i2c_dev_attr_groups[] = { | |
247 | &i2c_dev_attr_group, | |
248 | NULL | |
7b4fbc50 DB |
249 | }; |
250 | ||
0b2c3688 | 251 | static const struct dev_pm_ops i2c_device_pm_ops = { |
54067ee2 | 252 | .suspend = i2c_device_pm_suspend, |
253 | .resume = i2c_device_pm_resume, | |
254 | }; | |
255 | ||
e9ca9eb9 | 256 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
257 | .name = "i2c", |
258 | .match = i2c_device_match, | |
259 | .probe = i2c_device_probe, | |
260 | .remove = i2c_device_remove, | |
261 | .shutdown = i2c_device_shutdown, | |
262 | .suspend = i2c_device_suspend, | |
263 | .resume = i2c_device_resume, | |
54067ee2 | 264 | .pm = &i2c_device_pm_ops, |
b864c7d5 | 265 | }; |
e9ca9eb9 | 266 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 267 | |
51298d12 JD |
268 | static struct device_type i2c_client_type = { |
269 | .groups = i2c_dev_attr_groups, | |
270 | .uevent = i2c_device_uevent, | |
271 | .release = i2c_client_dev_release, | |
272 | }; | |
273 | ||
9b766b81 DB |
274 | |
275 | /** | |
276 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
277 | * @dev: device, probably from some driver model iterator | |
278 | * | |
279 | * When traversing the driver model tree, perhaps using driver model | |
280 | * iterators like @device_for_each_child(), you can't assume very much | |
281 | * about the nodes you find. Use this function to avoid oopses caused | |
282 | * by wrongly treating some non-I2C device as an i2c_client. | |
283 | */ | |
284 | struct i2c_client *i2c_verify_client(struct device *dev) | |
285 | { | |
51298d12 | 286 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
287 | ? to_i2c_client(dev) |
288 | : NULL; | |
289 | } | |
290 | EXPORT_SYMBOL(i2c_verify_client); | |
291 | ||
292 | ||
9c1600ed | 293 | /** |
f8a227e8 | 294 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
295 | * @adap: the adapter managing the device |
296 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 297 | * Context: can sleep |
9c1600ed | 298 | * |
f8a227e8 JD |
299 | * Create an i2c device. Binding is handled through driver model |
300 | * probe()/remove() methods. A driver may be bound to this device when we | |
301 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
302 | * load the driver module). This call is not appropriate for use by mainboard | |
303 | * initialization logic, which usually runs during an arch_initcall() long | |
304 | * before any i2c_adapter could exist. | |
9c1600ed DB |
305 | * |
306 | * This returns the new i2c client, which may be saved for later use with | |
307 | * i2c_unregister_device(); or NULL to indicate an error. | |
308 | */ | |
309 | struct i2c_client * | |
310 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
311 | { | |
312 | struct i2c_client *client; | |
313 | int status; | |
314 | ||
315 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
316 | if (!client) | |
317 | return NULL; | |
318 | ||
319 | client->adapter = adap; | |
320 | ||
321 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 322 | |
11f1f2af AV |
323 | if (info->archdata) |
324 | client->dev.archdata = *info->archdata; | |
325 | ||
ee35425c | 326 | client->flags = info->flags; |
9c1600ed DB |
327 | client->addr = info->addr; |
328 | client->irq = info->irq; | |
329 | ||
9c1600ed DB |
330 | strlcpy(client->name, info->type, sizeof(client->name)); |
331 | ||
f8a227e8 JD |
332 | /* Check for address business */ |
333 | status = i2c_check_addr(adap, client->addr); | |
334 | if (status) | |
335 | goto out_err; | |
336 | ||
337 | client->dev.parent = &client->adapter->dev; | |
338 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 339 | client->dev.type = &i2c_client_type; |
f8a227e8 JD |
340 | |
341 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), | |
342 | client->addr); | |
343 | status = device_register(&client->dev); | |
344 | if (status) | |
345 | goto out_err; | |
346 | ||
f8a227e8 JD |
347 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
348 | client->name, dev_name(&client->dev)); | |
349 | ||
9c1600ed | 350 | return client; |
f8a227e8 JD |
351 | |
352 | out_err: | |
353 | dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " | |
354 | "(%d)\n", client->name, client->addr, status); | |
355 | kfree(client); | |
356 | return NULL; | |
9c1600ed DB |
357 | } |
358 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
359 | ||
360 | ||
361 | /** | |
362 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
363 | * @client: value returned from i2c_new_device() | |
d64f73be | 364 | * Context: can sleep |
9c1600ed DB |
365 | */ |
366 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 367 | { |
a1d9e6e4 DB |
368 | device_unregister(&client->dev); |
369 | } | |
9c1600ed | 370 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
371 | |
372 | ||
60b129d7 JD |
373 | static const struct i2c_device_id dummy_id[] = { |
374 | { "dummy", 0 }, | |
375 | { }, | |
376 | }; | |
377 | ||
d2653e92 JD |
378 | static int dummy_probe(struct i2c_client *client, |
379 | const struct i2c_device_id *id) | |
380 | { | |
381 | return 0; | |
382 | } | |
383 | ||
384 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
385 | { |
386 | return 0; | |
387 | } | |
388 | ||
389 | static struct i2c_driver dummy_driver = { | |
390 | .driver.name = "dummy", | |
d2653e92 JD |
391 | .probe = dummy_probe, |
392 | .remove = dummy_remove, | |
60b129d7 | 393 | .id_table = dummy_id, |
e9f1373b DB |
394 | }; |
395 | ||
396 | /** | |
397 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
398 | * @adapter: the adapter managing the device | |
399 | * @address: seven bit address to be used | |
e9f1373b DB |
400 | * Context: can sleep |
401 | * | |
402 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
403 | * with devices that consume multiple addresses. Examples of such chips | |
404 | * include various EEPROMS (like 24c04 and 24c08 models). | |
405 | * | |
406 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
407 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
408 | * And second, this prevents the specified address from being bound to a | |
409 | * different driver. | |
410 | * | |
411 | * This returns the new i2c client, which should be saved for later use with | |
412 | * i2c_unregister_device(); or NULL to indicate an error. | |
413 | */ | |
09b8ce0a | 414 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
415 | { |
416 | struct i2c_board_info info = { | |
60b129d7 | 417 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
418 | }; |
419 | ||
e9f1373b DB |
420 | return i2c_new_device(adapter, &info); |
421 | } | |
422 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
423 | ||
f37dd80a DB |
424 | /* ------------------------------------------------------------------------- */ |
425 | ||
16ffadfc DB |
426 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
427 | ||
83eaaed0 | 428 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 429 | { |
ef2c8321 | 430 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
431 | complete(&adap->dev_released); |
432 | } | |
433 | ||
99cd8e25 JD |
434 | /* |
435 | * Let users instantiate I2C devices through sysfs. This can be used when | |
436 | * platform initialization code doesn't contain the proper data for | |
437 | * whatever reason. Also useful for drivers that do device detection and | |
438 | * detection fails, either because the device uses an unexpected address, | |
439 | * or this is a compatible device with different ID register values. | |
440 | * | |
441 | * Parameter checking may look overzealous, but we really don't want | |
442 | * the user to provide incorrect parameters. | |
443 | */ | |
444 | static ssize_t | |
445 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
446 | const char *buf, size_t count) | |
447 | { | |
448 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
449 | struct i2c_board_info info; | |
450 | struct i2c_client *client; | |
451 | char *blank, end; | |
452 | int res; | |
453 | ||
454 | dev_warn(dev, "The new_device interface is still experimental " | |
455 | "and may change in a near future\n"); | |
456 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
457 | ||
458 | blank = strchr(buf, ' '); | |
459 | if (!blank) { | |
460 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
461 | return -EINVAL; | |
462 | } | |
463 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
464 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
465 | return -EINVAL; | |
466 | } | |
467 | memcpy(info.type, buf, blank - buf); | |
468 | ||
469 | /* Parse remaining parameters, reject extra parameters */ | |
470 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
471 | if (res < 1) { | |
472 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
473 | return -EINVAL; | |
474 | } | |
475 | if (res > 1 && end != '\n') { | |
476 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
477 | return -EINVAL; | |
478 | } | |
479 | ||
480 | if (info.addr < 0x03 || info.addr > 0x77) { | |
481 | dev_err(dev, "%s: Invalid I2C address 0x%hx\n", "new_device", | |
482 | info.addr); | |
483 | return -EINVAL; | |
484 | } | |
485 | ||
486 | client = i2c_new_device(adap, &info); | |
487 | if (!client) | |
488 | return -EEXIST; | |
489 | ||
490 | /* Keep track of the added device */ | |
491 | mutex_lock(&core_lock); | |
492 | list_add_tail(&client->detected, &userspace_devices); | |
493 | mutex_unlock(&core_lock); | |
494 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", | |
495 | info.type, info.addr); | |
496 | ||
497 | return count; | |
498 | } | |
499 | ||
500 | /* | |
501 | * And of course let the users delete the devices they instantiated, if | |
502 | * they got it wrong. This interface can only be used to delete devices | |
503 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
504 | * don't delete devices to which some kernel code still has references. | |
505 | * | |
506 | * Parameter checking may look overzealous, but we really don't want | |
507 | * the user to delete the wrong device. | |
508 | */ | |
509 | static ssize_t | |
510 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
511 | const char *buf, size_t count) | |
512 | { | |
513 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
514 | struct i2c_client *client, *next; | |
515 | unsigned short addr; | |
516 | char end; | |
517 | int res; | |
518 | ||
519 | /* Parse parameters, reject extra parameters */ | |
520 | res = sscanf(buf, "%hi%c", &addr, &end); | |
521 | if (res < 1) { | |
522 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
523 | return -EINVAL; | |
524 | } | |
525 | if (res > 1 && end != '\n') { | |
526 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
527 | return -EINVAL; | |
528 | } | |
529 | ||
530 | /* Make sure the device was added through sysfs */ | |
531 | res = -ENOENT; | |
532 | mutex_lock(&core_lock); | |
533 | list_for_each_entry_safe(client, next, &userspace_devices, detected) { | |
534 | if (client->addr == addr && client->adapter == adap) { | |
535 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", | |
536 | "delete_device", client->name, client->addr); | |
537 | ||
538 | list_del(&client->detected); | |
539 | i2c_unregister_device(client); | |
540 | res = count; | |
541 | break; | |
542 | } | |
543 | } | |
544 | mutex_unlock(&core_lock); | |
545 | ||
546 | if (res < 0) | |
547 | dev_err(dev, "%s: Can't find device in list\n", | |
548 | "delete_device"); | |
549 | return res; | |
550 | } | |
551 | ||
4f8cf824 JD |
552 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
553 | static DEVICE_ATTR(delete_device, S_IWUSR, NULL, i2c_sysfs_delete_device); | |
554 | ||
555 | static struct attribute *i2c_adapter_attrs[] = { | |
556 | &dev_attr_name.attr, | |
557 | &dev_attr_new_device.attr, | |
558 | &dev_attr_delete_device.attr, | |
559 | NULL | |
560 | }; | |
561 | ||
562 | static struct attribute_group i2c_adapter_attr_group = { | |
563 | .attrs = i2c_adapter_attrs, | |
564 | }; | |
565 | ||
566 | static const struct attribute_group *i2c_adapter_attr_groups[] = { | |
567 | &i2c_adapter_attr_group, | |
568 | NULL | |
16ffadfc | 569 | }; |
b119dc3f | 570 | |
4f8cf824 JD |
571 | static struct device_type i2c_adapter_type = { |
572 | .groups = i2c_adapter_attr_groups, | |
573 | .release = i2c_adapter_dev_release, | |
1da177e4 LT |
574 | }; |
575 | ||
2bb5095a JD |
576 | #ifdef CONFIG_I2C_COMPAT |
577 | static struct class_compat *i2c_adapter_compat_class; | |
578 | #endif | |
579 | ||
9c1600ed DB |
580 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
581 | { | |
582 | struct i2c_devinfo *devinfo; | |
583 | ||
f18c41da | 584 | down_read(&__i2c_board_lock); |
9c1600ed DB |
585 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
586 | if (devinfo->busnum == adapter->nr | |
587 | && !i2c_new_device(adapter, | |
588 | &devinfo->board_info)) | |
09b8ce0a ZX |
589 | dev_err(&adapter->dev, |
590 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
591 | devinfo->board_info.addr); |
592 | } | |
f18c41da | 593 | up_read(&__i2c_board_lock); |
9c1600ed DB |
594 | } |
595 | ||
69b0089a JD |
596 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
597 | struct i2c_adapter *adap) | |
026526f5 | 598 | { |
4735c98f JD |
599 | /* Detect supported devices on that bus, and instantiate them */ |
600 | i2c_detect(adap, driver); | |
601 | ||
602 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 JD |
603 | if (driver->attach_adapter) { |
604 | /* We ignore the return code; if it fails, too bad */ | |
605 | driver->attach_adapter(adap); | |
606 | } | |
607 | return 0; | |
608 | } | |
609 | ||
69b0089a JD |
610 | static int __process_new_adapter(struct device_driver *d, void *data) |
611 | { | |
612 | return i2c_do_add_adapter(to_i2c_driver(d), data); | |
613 | } | |
614 | ||
6e13e641 | 615 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 616 | { |
026526f5 | 617 | int res = 0, dummy; |
1da177e4 | 618 | |
1d0b19c9 | 619 | /* Can't register until after driver model init */ |
35fc37f8 JD |
620 | if (unlikely(WARN_ON(!i2c_bus_type.p))) { |
621 | res = -EAGAIN; | |
622 | goto out_list; | |
623 | } | |
1d0b19c9 | 624 | |
194684e5 | 625 | rt_mutex_init(&adap->bus_lock); |
1da177e4 | 626 | |
8fcfef6e JD |
627 | /* Set default timeout to 1 second if not already set */ |
628 | if (adap->timeout == 0) | |
629 | adap->timeout = HZ; | |
630 | ||
27d9c183 | 631 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
632 | adap->dev.bus = &i2c_bus_type; |
633 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 JD |
634 | res = device_register(&adap->dev); |
635 | if (res) | |
636 | goto out_list; | |
1da177e4 | 637 | |
b6d7b3d1 JD |
638 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
639 | ||
2bb5095a JD |
640 | #ifdef CONFIG_I2C_COMPAT |
641 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
642 | adap->dev.parent); | |
643 | if (res) | |
644 | dev_warn(&adap->dev, | |
645 | "Failed to create compatibility class link\n"); | |
646 | #endif | |
647 | ||
729d6dd5 | 648 | /* create pre-declared device nodes */ |
6e13e641 DB |
649 | if (adap->nr < __i2c_first_dynamic_bus_num) |
650 | i2c_scan_static_board_info(adap); | |
651 | ||
4735c98f | 652 | /* Notify drivers */ |
35fc37f8 | 653 | mutex_lock(&core_lock); |
026526f5 | 654 | dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 655 | __process_new_adapter); |
caada32a | 656 | mutex_unlock(&core_lock); |
35fc37f8 JD |
657 | |
658 | return 0; | |
b119c6c9 | 659 | |
b119c6c9 | 660 | out_list: |
35fc37f8 | 661 | mutex_lock(&core_lock); |
b119c6c9 | 662 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
663 | mutex_unlock(&core_lock); |
664 | return res; | |
1da177e4 LT |
665 | } |
666 | ||
6e13e641 DB |
667 | /** |
668 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
669 | * @adapter: the adapter to add | |
d64f73be | 670 | * Context: can sleep |
6e13e641 DB |
671 | * |
672 | * This routine is used to declare an I2C adapter when its bus number | |
673 | * doesn't matter. Examples: for I2C adapters dynamically added by | |
674 | * USB links or PCI plugin cards. | |
675 | * | |
676 | * When this returns zero, a new bus number was allocated and stored | |
677 | * in adap->nr, and the specified adapter became available for clients. | |
678 | * Otherwise, a negative errno value is returned. | |
679 | */ | |
680 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
681 | { | |
682 | int id, res = 0; | |
683 | ||
684 | retry: | |
685 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
686 | return -ENOMEM; | |
687 | ||
caada32a | 688 | mutex_lock(&core_lock); |
6e13e641 DB |
689 | /* "above" here means "above or equal to", sigh */ |
690 | res = idr_get_new_above(&i2c_adapter_idr, adapter, | |
691 | __i2c_first_dynamic_bus_num, &id); | |
caada32a | 692 | mutex_unlock(&core_lock); |
6e13e641 DB |
693 | |
694 | if (res < 0) { | |
695 | if (res == -EAGAIN) | |
696 | goto retry; | |
697 | return res; | |
698 | } | |
699 | ||
700 | adapter->nr = id; | |
701 | return i2c_register_adapter(adapter); | |
702 | } | |
703 | EXPORT_SYMBOL(i2c_add_adapter); | |
704 | ||
705 | /** | |
706 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
707 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 708 | * Context: can sleep |
6e13e641 DB |
709 | * |
710 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
711 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
712 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
713 | * is used to properly configure I2C devices. |
714 | * | |
715 | * If no devices have pre-been declared for this bus, then be sure to | |
716 | * register the adapter before any dynamically allocated ones. Otherwise | |
717 | * the required bus ID may not be available. | |
718 | * | |
719 | * When this returns zero, the specified adapter became available for | |
720 | * clients using the bus number provided in adap->nr. Also, the table | |
721 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
722 | * and the appropriate driver model device nodes are created. Otherwise, a | |
723 | * negative errno value is returned. | |
724 | */ | |
725 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
726 | { | |
727 | int id; | |
728 | int status; | |
729 | ||
730 | if (adap->nr & ~MAX_ID_MASK) | |
731 | return -EINVAL; | |
732 | ||
733 | retry: | |
734 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
735 | return -ENOMEM; | |
736 | ||
caada32a | 737 | mutex_lock(&core_lock); |
6e13e641 DB |
738 | /* "above" here means "above or equal to", sigh; |
739 | * we need the "equal to" result to force the result | |
740 | */ | |
741 | status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id); | |
742 | if (status == 0 && id != adap->nr) { | |
743 | status = -EBUSY; | |
744 | idr_remove(&i2c_adapter_idr, id); | |
745 | } | |
caada32a | 746 | mutex_unlock(&core_lock); |
6e13e641 DB |
747 | if (status == -EAGAIN) |
748 | goto retry; | |
749 | ||
750 | if (status == 0) | |
751 | status = i2c_register_adapter(adap); | |
752 | return status; | |
753 | } | |
754 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
755 | ||
69b0089a JD |
756 | static int i2c_do_del_adapter(struct i2c_driver *driver, |
757 | struct i2c_adapter *adapter) | |
026526f5 | 758 | { |
4735c98f | 759 | struct i2c_client *client, *_n; |
026526f5 JD |
760 | int res; |
761 | ||
acec211c JD |
762 | /* Remove the devices we created ourselves as the result of hardware |
763 | * probing (using a driver's detect method) */ | |
4735c98f JD |
764 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
765 | if (client->adapter == adapter) { | |
766 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
767 | client->name, client->addr); | |
768 | list_del(&client->detected); | |
769 | i2c_unregister_device(client); | |
770 | } | |
771 | } | |
772 | ||
026526f5 JD |
773 | if (!driver->detach_adapter) |
774 | return 0; | |
775 | res = driver->detach_adapter(adapter); | |
776 | if (res) | |
777 | dev_err(&adapter->dev, "detach_adapter failed (%d) " | |
778 | "for driver [%s]\n", res, driver->driver.name); | |
779 | return res; | |
780 | } | |
781 | ||
e549c2b5 JD |
782 | static int __unregister_client(struct device *dev, void *dummy) |
783 | { | |
784 | struct i2c_client *client = i2c_verify_client(dev); | |
785 | if (client) | |
786 | i2c_unregister_device(client); | |
787 | return 0; | |
788 | } | |
789 | ||
69b0089a JD |
790 | static int __process_removed_adapter(struct device_driver *d, void *data) |
791 | { | |
792 | return i2c_do_del_adapter(to_i2c_driver(d), data); | |
793 | } | |
794 | ||
d64f73be DB |
795 | /** |
796 | * i2c_del_adapter - unregister I2C adapter | |
797 | * @adap: the adapter being unregistered | |
798 | * Context: can sleep | |
799 | * | |
800 | * This unregisters an I2C adapter which was previously registered | |
801 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
802 | */ | |
1da177e4 LT |
803 | int i2c_del_adapter(struct i2c_adapter *adap) |
804 | { | |
1da177e4 | 805 | int res = 0; |
35fc37f8 | 806 | struct i2c_adapter *found; |
bbd2d9c9 | 807 | struct i2c_client *client, *next; |
1da177e4 LT |
808 | |
809 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
810 | mutex_lock(&core_lock); |
811 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
812 | mutex_unlock(&core_lock); | |
813 | if (found != adap) { | |
b6d7b3d1 JD |
814 | pr_debug("i2c-core: attempting to delete unregistered " |
815 | "adapter [%s]\n", adap->name); | |
35fc37f8 | 816 | return -EINVAL; |
1da177e4 LT |
817 | } |
818 | ||
026526f5 | 819 | /* Tell drivers about this removal */ |
35fc37f8 | 820 | mutex_lock(&core_lock); |
026526f5 | 821 | res = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 822 | __process_removed_adapter); |
35fc37f8 | 823 | mutex_unlock(&core_lock); |
026526f5 | 824 | if (res) |
35fc37f8 | 825 | return res; |
1da177e4 | 826 | |
bbd2d9c9 JD |
827 | /* Remove devices instantiated from sysfs */ |
828 | list_for_each_entry_safe(client, next, &userspace_devices, detected) { | |
829 | if (client->adapter == adap) { | |
830 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", | |
831 | client->name, client->addr); | |
832 | list_del(&client->detected); | |
833 | i2c_unregister_device(client); | |
834 | } | |
835 | } | |
836 | ||
e549c2b5 JD |
837 | /* Detach any active clients. This can't fail, thus we do not |
838 | checking the returned value. */ | |
839 | res = device_for_each_child(&adap->dev, NULL, __unregister_client); | |
1da177e4 | 840 | |
2bb5095a JD |
841 | #ifdef CONFIG_I2C_COMPAT |
842 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
843 | adap->dev.parent); | |
844 | #endif | |
845 | ||
c5567521 TLSC |
846 | /* device name is gone after device_unregister */ |
847 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); | |
848 | ||
1da177e4 LT |
849 | /* clean up the sysfs representation */ |
850 | init_completion(&adap->dev_released); | |
1da177e4 | 851 | device_unregister(&adap->dev); |
1da177e4 LT |
852 | |
853 | /* wait for sysfs to drop all references */ | |
854 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 855 | |
6e13e641 | 856 | /* free bus id */ |
35fc37f8 | 857 | mutex_lock(&core_lock); |
1da177e4 | 858 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 859 | mutex_unlock(&core_lock); |
1da177e4 | 860 | |
bd4bc3db JD |
861 | /* Clear the device structure in case this adapter is ever going to be |
862 | added again */ | |
863 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
864 | ||
35fc37f8 | 865 | return 0; |
1da177e4 | 866 | } |
c0564606 | 867 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 LT |
868 | |
869 | ||
7b4fbc50 DB |
870 | /* ------------------------------------------------------------------------- */ |
871 | ||
69b0089a | 872 | static int __process_new_driver(struct device *dev, void *data) |
7f101a97 | 873 | { |
4f8cf824 JD |
874 | if (dev->type != &i2c_adapter_type) |
875 | return 0; | |
69b0089a | 876 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
7f101a97 DY |
877 | } |
878 | ||
7b4fbc50 DB |
879 | /* |
880 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 881 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
882 | */ |
883 | ||
de59cf9e | 884 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 885 | { |
7eebcb7c | 886 | int res; |
1da177e4 | 887 | |
1d0b19c9 DB |
888 | /* Can't register until after driver model init */ |
889 | if (unlikely(WARN_ON(!i2c_bus_type.p))) | |
890 | return -EAGAIN; | |
891 | ||
1da177e4 | 892 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 893 | driver->driver.owner = owner; |
1da177e4 | 894 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 895 | |
729d6dd5 | 896 | /* When registration returns, the driver core |
6e13e641 DB |
897 | * will have called probe() for all matching-but-unbound devices. |
898 | */ | |
1da177e4 LT |
899 | res = driver_register(&driver->driver); |
900 | if (res) | |
7eebcb7c | 901 | return res; |
438d6c2c | 902 | |
35d8b2e6 | 903 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 904 | |
4735c98f JD |
905 | INIT_LIST_HEAD(&driver->clients); |
906 | /* Walk the adapters that are already present */ | |
35fc37f8 | 907 | mutex_lock(&core_lock); |
69b0089a | 908 | bus_for_each_dev(&i2c_bus_type, NULL, driver, __process_new_driver); |
7f101a97 | 909 | mutex_unlock(&core_lock); |
35fc37f8 | 910 | |
7f101a97 DY |
911 | return 0; |
912 | } | |
913 | EXPORT_SYMBOL(i2c_register_driver); | |
914 | ||
69b0089a | 915 | static int __process_removed_driver(struct device *dev, void *data) |
7f101a97 | 916 | { |
4f8cf824 JD |
917 | if (dev->type != &i2c_adapter_type) |
918 | return 0; | |
69b0089a | 919 | return i2c_do_del_adapter(data, to_i2c_adapter(dev)); |
1da177e4 LT |
920 | } |
921 | ||
a1d9e6e4 DB |
922 | /** |
923 | * i2c_del_driver - unregister I2C driver | |
924 | * @driver: the driver being unregistered | |
d64f73be | 925 | * Context: can sleep |
a1d9e6e4 | 926 | */ |
b3e82096 | 927 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 928 | { |
caada32a | 929 | mutex_lock(&core_lock); |
69b0089a | 930 | bus_for_each_dev(&i2c_bus_type, NULL, driver, __process_removed_driver); |
35fc37f8 | 931 | mutex_unlock(&core_lock); |
1da177e4 LT |
932 | |
933 | driver_unregister(&driver->driver); | |
35d8b2e6 | 934 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 935 | } |
c0564606 | 936 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 937 | |
7b4fbc50 DB |
938 | /* ------------------------------------------------------------------------- */ |
939 | ||
9b766b81 | 940 | static int __i2c_check_addr(struct device *dev, void *addrp) |
1da177e4 | 941 | { |
9b766b81 DB |
942 | struct i2c_client *client = i2c_verify_client(dev); |
943 | int addr = *(int *)addrp; | |
1da177e4 | 944 | |
9b766b81 DB |
945 | if (client && client->addr == addr) |
946 | return -EBUSY; | |
1da177e4 LT |
947 | return 0; |
948 | } | |
949 | ||
5e31c2bd | 950 | static int i2c_check_addr(struct i2c_adapter *adapter, int addr) |
1da177e4 | 951 | { |
9b766b81 | 952 | return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr); |
1da177e4 LT |
953 | } |
954 | ||
e48d3319 JD |
955 | /** |
956 | * i2c_use_client - increments the reference count of the i2c client structure | |
957 | * @client: the client being referenced | |
958 | * | |
959 | * Each live reference to a client should be refcounted. The driver model does | |
960 | * that automatically as part of driver binding, so that most drivers don't | |
961 | * need to do this explicitly: they hold a reference until they're unbound | |
962 | * from the device. | |
963 | * | |
964 | * A pointer to the client with the incremented reference counter is returned. | |
965 | */ | |
966 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 967 | { |
6ea438ec DB |
968 | if (client && get_device(&client->dev)) |
969 | return client; | |
970 | return NULL; | |
1da177e4 | 971 | } |
c0564606 | 972 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 973 | |
e48d3319 JD |
974 | /** |
975 | * i2c_release_client - release a use of the i2c client structure | |
976 | * @client: the client being no longer referenced | |
977 | * | |
978 | * Must be called when a user of a client is finished with it. | |
979 | */ | |
980 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 981 | { |
6ea438ec DB |
982 | if (client) |
983 | put_device(&client->dev); | |
1da177e4 | 984 | } |
c0564606 | 985 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 986 | |
9b766b81 DB |
987 | struct i2c_cmd_arg { |
988 | unsigned cmd; | |
989 | void *arg; | |
990 | }; | |
991 | ||
992 | static int i2c_cmd(struct device *dev, void *_arg) | |
993 | { | |
994 | struct i2c_client *client = i2c_verify_client(dev); | |
995 | struct i2c_cmd_arg *arg = _arg; | |
996 | ||
997 | if (client && client->driver && client->driver->command) | |
998 | client->driver->command(client, arg->cmd, arg->arg); | |
999 | return 0; | |
1000 | } | |
1001 | ||
1da177e4 LT |
1002 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
1003 | { | |
9b766b81 | 1004 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 1005 | |
9b766b81 DB |
1006 | cmd_arg.cmd = cmd; |
1007 | cmd_arg.arg = arg; | |
1008 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 1009 | } |
c0564606 | 1010 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
1011 | |
1012 | static int __init i2c_init(void) | |
1013 | { | |
1014 | int retval; | |
1015 | ||
1016 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
1017 | if (retval) |
1018 | return retval; | |
2bb5095a JD |
1019 | #ifdef CONFIG_I2C_COMPAT |
1020 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
1021 | if (!i2c_adapter_compat_class) { | |
1022 | retval = -ENOMEM; | |
1023 | goto bus_err; | |
1024 | } | |
1025 | #endif | |
e9f1373b DB |
1026 | retval = i2c_add_driver(&dummy_driver); |
1027 | if (retval) | |
2bb5095a | 1028 | goto class_err; |
e9f1373b DB |
1029 | return 0; |
1030 | ||
2bb5095a JD |
1031 | class_err: |
1032 | #ifdef CONFIG_I2C_COMPAT | |
1033 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 1034 | bus_err: |
2bb5095a | 1035 | #endif |
e9f1373b DB |
1036 | bus_unregister(&i2c_bus_type); |
1037 | return retval; | |
1da177e4 LT |
1038 | } |
1039 | ||
1040 | static void __exit i2c_exit(void) | |
1041 | { | |
e9f1373b | 1042 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
1043 | #ifdef CONFIG_I2C_COMPAT |
1044 | class_compat_unregister(i2c_adapter_compat_class); | |
1045 | #endif | |
1da177e4 LT |
1046 | bus_unregister(&i2c_bus_type); |
1047 | } | |
1048 | ||
a10f9e7c DB |
1049 | /* We must initialize early, because some subsystems register i2c drivers |
1050 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1051 | */ | |
1052 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1053 | module_exit(i2c_exit); |
1054 | ||
1055 | /* ---------------------------------------------------- | |
1056 | * the functional interface to the i2c busses. | |
1057 | * ---------------------------------------------------- | |
1058 | */ | |
1059 | ||
a1cdedac DB |
1060 | /** |
1061 | * i2c_transfer - execute a single or combined I2C message | |
1062 | * @adap: Handle to I2C bus | |
1063 | * @msgs: One or more messages to execute before STOP is issued to | |
1064 | * terminate the operation; each message begins with a START. | |
1065 | * @num: Number of messages to be executed. | |
1066 | * | |
1067 | * Returns negative errno, else the number of messages executed. | |
1068 | * | |
1069 | * Note that there is no requirement that each message be sent to | |
1070 | * the same slave address, although that is the most common model. | |
1071 | */ | |
09b8ce0a | 1072 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 1073 | { |
66b650f0 CW |
1074 | unsigned long orig_jiffies; |
1075 | int ret, try; | |
1da177e4 | 1076 | |
a1cdedac DB |
1077 | /* REVISIT the fault reporting model here is weak: |
1078 | * | |
1079 | * - When we get an error after receiving N bytes from a slave, | |
1080 | * there is no way to report "N". | |
1081 | * | |
1082 | * - When we get a NAK after transmitting N bytes to a slave, | |
1083 | * there is no way to report "N" ... or to let the master | |
1084 | * continue executing the rest of this combined message, if | |
1085 | * that's the appropriate response. | |
1086 | * | |
1087 | * - When for example "num" is two and we successfully complete | |
1088 | * the first message but get an error part way through the | |
1089 | * second, it's unclear whether that should be reported as | |
1090 | * one (discarding status on the second message) or errno | |
1091 | * (discarding status on the first one). | |
1092 | */ | |
1093 | ||
1da177e4 LT |
1094 | if (adap->algo->master_xfer) { |
1095 | #ifdef DEBUG | |
1096 | for (ret = 0; ret < num; ret++) { | |
1097 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
1098 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
1099 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
1100 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
1101 | } |
1102 | #endif | |
1103 | ||
cea443a8 | 1104 | if (in_atomic() || irqs_disabled()) { |
194684e5 | 1105 | ret = rt_mutex_trylock(&adap->bus_lock); |
cea443a8 MR |
1106 | if (!ret) |
1107 | /* I2C activity is ongoing. */ | |
1108 | return -EAGAIN; | |
1109 | } else { | |
194684e5 | 1110 | rt_mutex_lock(&adap->bus_lock); |
cea443a8 MR |
1111 | } |
1112 | ||
66b650f0 CW |
1113 | /* Retry automatically on arbitration loss */ |
1114 | orig_jiffies = jiffies; | |
1115 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
1116 | ret = adap->algo->master_xfer(adap, msgs, num); | |
1117 | if (ret != -EAGAIN) | |
1118 | break; | |
1119 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
1120 | break; | |
1121 | } | |
194684e5 | 1122 | rt_mutex_unlock(&adap->bus_lock); |
1da177e4 LT |
1123 | |
1124 | return ret; | |
1125 | } else { | |
1126 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1127 | return -EOPNOTSUPP; |
1da177e4 LT |
1128 | } |
1129 | } | |
c0564606 | 1130 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1131 | |
a1cdedac DB |
1132 | /** |
1133 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1134 | * @client: Handle to slave device | |
1135 | * @buf: Data that will be written to the slave | |
1136 | * @count: How many bytes to write | |
1137 | * | |
1138 | * Returns negative errno, or else the number of bytes written. | |
1139 | */ | |
1da177e4 LT |
1140 | int i2c_master_send(struct i2c_client *client,const char *buf ,int count) |
1141 | { | |
1142 | int ret; | |
1143 | struct i2c_adapter *adap=client->adapter; | |
1144 | struct i2c_msg msg; | |
1145 | ||
815f55f2 JD |
1146 | msg.addr = client->addr; |
1147 | msg.flags = client->flags & I2C_M_TEN; | |
1148 | msg.len = count; | |
1149 | msg.buf = (char *)buf; | |
438d6c2c | 1150 | |
815f55f2 | 1151 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1152 | |
815f55f2 JD |
1153 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes |
1154 | transmitted, else error code. */ | |
1155 | return (ret == 1) ? count : ret; | |
1da177e4 | 1156 | } |
c0564606 | 1157 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1158 | |
a1cdedac DB |
1159 | /** |
1160 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1161 | * @client: Handle to slave device | |
1162 | * @buf: Where to store data read from slave | |
1163 | * @count: How many bytes to read | |
1164 | * | |
1165 | * Returns negative errno, or else the number of bytes read. | |
1166 | */ | |
1da177e4 LT |
1167 | int i2c_master_recv(struct i2c_client *client, char *buf ,int count) |
1168 | { | |
1169 | struct i2c_adapter *adap=client->adapter; | |
1170 | struct i2c_msg msg; | |
1171 | int ret; | |
815f55f2 JD |
1172 | |
1173 | msg.addr = client->addr; | |
1174 | msg.flags = client->flags & I2C_M_TEN; | |
1175 | msg.flags |= I2C_M_RD; | |
1176 | msg.len = count; | |
1177 | msg.buf = buf; | |
1178 | ||
1179 | ret = i2c_transfer(adap, &msg, 1); | |
1180 | ||
1181 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1182 | transmitted, else error code. */ | |
1183 | return (ret == 1) ? count : ret; | |
1da177e4 | 1184 | } |
c0564606 | 1185 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1186 | |
1da177e4 LT |
1187 | /* ---------------------------------------------------- |
1188 | * the i2c address scanning function | |
1189 | * Will not work for 10-bit addresses! | |
1190 | * ---------------------------------------------------- | |
1191 | */ | |
1da177e4 | 1192 | |
ccfbbd08 | 1193 | static int i2c_detect_address(struct i2c_client *temp_client, |
4735c98f JD |
1194 | struct i2c_driver *driver) |
1195 | { | |
1196 | struct i2c_board_info info; | |
1197 | struct i2c_adapter *adapter = temp_client->adapter; | |
1198 | int addr = temp_client->addr; | |
1199 | int err; | |
1200 | ||
1201 | /* Make sure the address is valid */ | |
1202 | if (addr < 0x03 || addr > 0x77) { | |
1203 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", | |
1204 | addr); | |
1205 | return -EINVAL; | |
1206 | } | |
1207 | ||
1208 | /* Skip if already in use */ | |
1209 | if (i2c_check_addr(adapter, addr)) | |
1210 | return 0; | |
1211 | ||
ccfbbd08 JD |
1212 | /* Make sure there is something at this address */ |
1213 | if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL) < 0) | |
1214 | return 0; | |
4735c98f | 1215 | |
ccfbbd08 JD |
1216 | /* Prevent 24RF08 corruption */ |
1217 | if ((addr & ~0x0f) == 0x50) | |
1218 | i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL); | |
4735c98f JD |
1219 | |
1220 | /* Finally call the custom detection function */ | |
1221 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
1222 | info.addr = addr; | |
310ec792 | 1223 | err = driver->detect(temp_client, &info); |
4735c98f JD |
1224 | if (err) { |
1225 | /* -ENODEV is returned if the detection fails. We catch it | |
1226 | here as this isn't an error. */ | |
1227 | return err == -ENODEV ? 0 : err; | |
1228 | } | |
1229 | ||
1230 | /* Consistency check */ | |
1231 | if (info.type[0] == '\0') { | |
1232 | dev_err(&adapter->dev, "%s detection function provided " | |
1233 | "no name for 0x%x\n", driver->driver.name, | |
1234 | addr); | |
1235 | } else { | |
1236 | struct i2c_client *client; | |
1237 | ||
1238 | /* Detection succeeded, instantiate the device */ | |
1239 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", | |
1240 | info.type, info.addr); | |
1241 | client = i2c_new_device(adapter, &info); | |
1242 | if (client) | |
1243 | list_add_tail(&client->detected, &driver->clients); | |
1244 | else | |
1245 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
1246 | info.type, info.addr); | |
1247 | } | |
1248 | return 0; | |
1249 | } | |
1250 | ||
1251 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
1252 | { | |
c3813d6a | 1253 | const unsigned short *address_list; |
4735c98f JD |
1254 | struct i2c_client *temp_client; |
1255 | int i, err = 0; | |
1256 | int adap_id = i2c_adapter_id(adapter); | |
1257 | ||
c3813d6a JD |
1258 | address_list = driver->address_list; |
1259 | if (!driver->detect || !address_list) | |
4735c98f JD |
1260 | return 0; |
1261 | ||
1262 | /* Set up a temporary client to help detect callback */ | |
1263 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
1264 | if (!temp_client) | |
1265 | return -ENOMEM; | |
1266 | temp_client->adapter = adapter; | |
1267 | ||
4329cf86 JD |
1268 | /* Stop here if the classes do not match */ |
1269 | if (!(adapter->class & driver->class)) | |
1270 | goto exit_free; | |
1271 | ||
4735c98f JD |
1272 | /* Stop here if we can't use SMBUS_QUICK */ |
1273 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) { | |
c3813d6a | 1274 | if (address_list[0] == I2C_CLIENT_END) |
4735c98f JD |
1275 | goto exit_free; |
1276 | ||
1277 | dev_warn(&adapter->dev, "SMBus Quick command not supported, " | |
1278 | "can't probe for chips\n"); | |
1279 | err = -EOPNOTSUPP; | |
1280 | goto exit_free; | |
1281 | } | |
1282 | ||
c3813d6a | 1283 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
4735c98f | 1284 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
c3813d6a JD |
1285 | "addr 0x%02x\n", adap_id, address_list[i]); |
1286 | temp_client->addr = address_list[i]; | |
ccfbbd08 | 1287 | err = i2c_detect_address(temp_client, driver); |
4735c98f JD |
1288 | if (err) |
1289 | goto exit_free; | |
1290 | } | |
1291 | ||
1292 | exit_free: | |
1293 | kfree(temp_client); | |
1294 | return err; | |
1295 | } | |
1296 | ||
12b5053a JD |
1297 | struct i2c_client * |
1298 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1299 | struct i2c_board_info *info, | |
1300 | unsigned short const *addr_list) | |
1301 | { | |
1302 | int i; | |
1303 | ||
1304 | /* Stop here if the bus doesn't support probing */ | |
1305 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { | |
1306 | dev_err(&adap->dev, "Probing not supported\n"); | |
1307 | return NULL; | |
1308 | } | |
1309 | ||
12b5053a JD |
1310 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1311 | /* Check address validity */ | |
1312 | if (addr_list[i] < 0x03 || addr_list[i] > 0x77) { | |
1313 | dev_warn(&adap->dev, "Invalid 7-bit address " | |
1314 | "0x%02x\n", addr_list[i]); | |
1315 | continue; | |
1316 | } | |
1317 | ||
1318 | /* Check address availability */ | |
9b766b81 | 1319 | if (i2c_check_addr(adap, addr_list[i])) { |
12b5053a JD |
1320 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1321 | "use, not probing\n", addr_list[i]); | |
1322 | continue; | |
1323 | } | |
1324 | ||
1325 | /* Test address responsiveness | |
1326 | The default probe method is a quick write, but it is known | |
1327 | to corrupt the 24RF08 EEPROMs due to a state machine bug, | |
1328 | and could also irreversibly write-protect some EEPROMs, so | |
1329 | for address ranges 0x30-0x37 and 0x50-0x5f, we use a byte | |
1330 | read instead. Also, some bus drivers don't implement | |
1331 | quick write, so we fallback to a byte read it that case | |
1332 | too. */ | |
1333 | if ((addr_list[i] & ~0x07) == 0x30 | |
1334 | || (addr_list[i] & ~0x0f) == 0x50 | |
1335 | || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) { | |
b25b791b HV |
1336 | union i2c_smbus_data data; |
1337 | ||
12b5053a JD |
1338 | if (i2c_smbus_xfer(adap, addr_list[i], 0, |
1339 | I2C_SMBUS_READ, 0, | |
b25b791b | 1340 | I2C_SMBUS_BYTE, &data) >= 0) |
12b5053a JD |
1341 | break; |
1342 | } else { | |
1343 | if (i2c_smbus_xfer(adap, addr_list[i], 0, | |
1344 | I2C_SMBUS_WRITE, 0, | |
1345 | I2C_SMBUS_QUICK, NULL) >= 0) | |
1346 | break; | |
1347 | } | |
1348 | } | |
12b5053a JD |
1349 | |
1350 | if (addr_list[i] == I2C_CLIENT_END) { | |
1351 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1352 | return NULL; | |
1353 | } | |
1354 | ||
1355 | info->addr = addr_list[i]; | |
1356 | return i2c_new_device(adap, info); | |
1357 | } | |
1358 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
1359 | ||
1da177e4 LT |
1360 | struct i2c_adapter* i2c_get_adapter(int id) |
1361 | { | |
1da177e4 | 1362 | struct i2c_adapter *adapter; |
438d6c2c | 1363 | |
caada32a | 1364 | mutex_lock(&core_lock); |
1cf92b45 | 1365 | adapter = idr_find(&i2c_adapter_idr, id); |
a0920e10 MH |
1366 | if (adapter && !try_module_get(adapter->owner)) |
1367 | adapter = NULL; | |
1368 | ||
caada32a | 1369 | mutex_unlock(&core_lock); |
a0920e10 | 1370 | return adapter; |
1da177e4 | 1371 | } |
c0564606 | 1372 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
1373 | |
1374 | void i2c_put_adapter(struct i2c_adapter *adap) | |
1375 | { | |
1376 | module_put(adap->owner); | |
1377 | } | |
c0564606 | 1378 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
1379 | |
1380 | /* The SMBus parts */ | |
1381 | ||
438d6c2c | 1382 | #define POLY (0x1070U << 3) |
09b8ce0a | 1383 | static u8 crc8(u16 data) |
1da177e4 LT |
1384 | { |
1385 | int i; | |
438d6c2c | 1386 | |
1da177e4 | 1387 | for(i = 0; i < 8; i++) { |
438d6c2c | 1388 | if (data & 0x8000) |
1da177e4 LT |
1389 | data = data ^ POLY; |
1390 | data = data << 1; | |
1391 | } | |
1392 | return (u8)(data >> 8); | |
1393 | } | |
1394 | ||
421ef47b JD |
1395 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
1396 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
1397 | { |
1398 | int i; | |
1399 | ||
1400 | for(i = 0; i < count; i++) | |
421ef47b | 1401 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
1402 | return crc; |
1403 | } | |
1404 | ||
421ef47b JD |
1405 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
1406 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 1407 | { |
421ef47b JD |
1408 | /* The address will be sent first */ |
1409 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
1410 | pec = i2c_smbus_pec(pec, &addr, 1); | |
1411 | ||
1412 | /* The data buffer follows */ | |
1413 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
1414 | } |
1415 | ||
421ef47b JD |
1416 | /* Used for write only transactions */ |
1417 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 1418 | { |
421ef47b JD |
1419 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
1420 | msg->len++; | |
1da177e4 LT |
1421 | } |
1422 | ||
421ef47b JD |
1423 | /* Return <0 on CRC error |
1424 | If there was a write before this read (most cases) we need to take the | |
1425 | partial CRC from the write part into account. | |
1426 | Note that this function does modify the message (we need to decrease the | |
1427 | message length to hide the CRC byte from the caller). */ | |
1428 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 1429 | { |
421ef47b JD |
1430 | u8 rpec = msg->buf[--msg->len]; |
1431 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 1432 | |
1da177e4 LT |
1433 | if (rpec != cpec) { |
1434 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
1435 | rpec, cpec); | |
24a5bb7b | 1436 | return -EBADMSG; |
1da177e4 | 1437 | } |
438d6c2c | 1438 | return 0; |
1da177e4 LT |
1439 | } |
1440 | ||
a1cdedac DB |
1441 | /** |
1442 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
1443 | * @client: Handle to slave device | |
1444 | * | |
1445 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
1446 | * else the byte received from the device. | |
1447 | */ | |
1da177e4 LT |
1448 | s32 i2c_smbus_read_byte(struct i2c_client *client) |
1449 | { | |
1450 | union i2c_smbus_data data; | |
24a5bb7b DB |
1451 | int status; |
1452 | ||
1453 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1454 | I2C_SMBUS_READ, 0, | |
1455 | I2C_SMBUS_BYTE, &data); | |
1456 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1457 | } |
c0564606 | 1458 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 1459 | |
a1cdedac DB |
1460 | /** |
1461 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
1462 | * @client: Handle to slave device | |
1463 | * @value: Byte to be sent | |
1464 | * | |
1465 | * This executes the SMBus "send byte" protocol, returning negative errno | |
1466 | * else zero on success. | |
1467 | */ | |
1da177e4 LT |
1468 | s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) |
1469 | { | |
1da177e4 | 1470 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
421ef47b | 1471 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 1472 | } |
c0564606 | 1473 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 1474 | |
a1cdedac DB |
1475 | /** |
1476 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
1477 | * @client: Handle to slave device | |
1478 | * @command: Byte interpreted by slave | |
1479 | * | |
1480 | * This executes the SMBus "read byte" protocol, returning negative errno | |
1481 | * else a data byte received from the device. | |
1482 | */ | |
1da177e4 LT |
1483 | s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) |
1484 | { | |
1485 | union i2c_smbus_data data; | |
24a5bb7b DB |
1486 | int status; |
1487 | ||
1488 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1489 | I2C_SMBUS_READ, command, | |
1490 | I2C_SMBUS_BYTE_DATA, &data); | |
1491 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1492 | } |
c0564606 | 1493 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 1494 | |
a1cdedac DB |
1495 | /** |
1496 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
1497 | * @client: Handle to slave device | |
1498 | * @command: Byte interpreted by slave | |
1499 | * @value: Byte being written | |
1500 | * | |
1501 | * This executes the SMBus "write byte" protocol, returning negative errno | |
1502 | * else zero on success. | |
1503 | */ | |
1da177e4 LT |
1504 | s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) |
1505 | { | |
1506 | union i2c_smbus_data data; | |
1507 | data.byte = value; | |
1508 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1509 | I2C_SMBUS_WRITE,command, | |
1510 | I2C_SMBUS_BYTE_DATA,&data); | |
1511 | } | |
c0564606 | 1512 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 1513 | |
a1cdedac DB |
1514 | /** |
1515 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
1516 | * @client: Handle to slave device | |
1517 | * @command: Byte interpreted by slave | |
1518 | * | |
1519 | * This executes the SMBus "read word" protocol, returning negative errno | |
1520 | * else a 16-bit unsigned "word" received from the device. | |
1521 | */ | |
1da177e4 LT |
1522 | s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) |
1523 | { | |
1524 | union i2c_smbus_data data; | |
24a5bb7b DB |
1525 | int status; |
1526 | ||
1527 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1528 | I2C_SMBUS_READ, command, | |
1529 | I2C_SMBUS_WORD_DATA, &data); | |
1530 | return (status < 0) ? status : data.word; | |
1da177e4 | 1531 | } |
c0564606 | 1532 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 1533 | |
a1cdedac DB |
1534 | /** |
1535 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
1536 | * @client: Handle to slave device | |
1537 | * @command: Byte interpreted by slave | |
1538 | * @value: 16-bit "word" being written | |
1539 | * | |
1540 | * This executes the SMBus "write word" protocol, returning negative errno | |
1541 | * else zero on success. | |
1542 | */ | |
1da177e4 LT |
1543 | s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) |
1544 | { | |
1545 | union i2c_smbus_data data; | |
1546 | data.word = value; | |
1547 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1548 | I2C_SMBUS_WRITE,command, | |
1549 | I2C_SMBUS_WORD_DATA,&data); | |
1550 | } | |
c0564606 | 1551 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 1552 | |
596c88f4 PM |
1553 | /** |
1554 | * i2c_smbus_process_call - SMBus "process call" protocol | |
1555 | * @client: Handle to slave device | |
1556 | * @command: Byte interpreted by slave | |
1557 | * @value: 16-bit "word" being written | |
1558 | * | |
1559 | * This executes the SMBus "process call" protocol, returning negative errno | |
1560 | * else a 16-bit unsigned "word" received from the device. | |
1561 | */ | |
1562 | s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value) | |
1563 | { | |
1564 | union i2c_smbus_data data; | |
1565 | int status; | |
1566 | data.word = value; | |
1567 | ||
1568 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1569 | I2C_SMBUS_WRITE, command, | |
1570 | I2C_SMBUS_PROC_CALL, &data); | |
1571 | return (status < 0) ? status : data.word; | |
1572 | } | |
1573 | EXPORT_SYMBOL(i2c_smbus_process_call); | |
1574 | ||
a64ec07d | 1575 | /** |
a1cdedac | 1576 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 1577 | * @client: Handle to slave device |
a1cdedac | 1578 | * @command: Byte interpreted by slave |
a64ec07d DB |
1579 | * @values: Byte array into which data will be read; big enough to hold |
1580 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
1581 | * | |
a1cdedac DB |
1582 | * This executes the SMBus "block read" protocol, returning negative errno |
1583 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
1584 | * |
1585 | * Note that using this function requires that the client's adapter support | |
1586 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
1587 | * support this; its emulation through I2C messaging relies on a specific | |
1588 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
1589 | */ | |
b86a1bc8 JD |
1590 | s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, |
1591 | u8 *values) | |
1592 | { | |
1593 | union i2c_smbus_data data; | |
24a5bb7b | 1594 | int status; |
b86a1bc8 | 1595 | |
24a5bb7b DB |
1596 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1597 | I2C_SMBUS_READ, command, | |
1598 | I2C_SMBUS_BLOCK_DATA, &data); | |
1599 | if (status) | |
1600 | return status; | |
b86a1bc8 JD |
1601 | |
1602 | memcpy(values, &data.block[1], data.block[0]); | |
1603 | return data.block[0]; | |
1604 | } | |
1605 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
1606 | ||
a1cdedac DB |
1607 | /** |
1608 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
1609 | * @client: Handle to slave device | |
1610 | * @command: Byte interpreted by slave | |
1611 | * @length: Size of data block; SMBus allows at most 32 bytes | |
1612 | * @values: Byte array which will be written. | |
1613 | * | |
1614 | * This executes the SMBus "block write" protocol, returning negative errno | |
1615 | * else zero on success. | |
1616 | */ | |
1da177e4 | 1617 | s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1618 | u8 length, const u8 *values) |
1da177e4 LT |
1619 | { |
1620 | union i2c_smbus_data data; | |
7656032b | 1621 | |
1da177e4 LT |
1622 | if (length > I2C_SMBUS_BLOCK_MAX) |
1623 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 1624 | data.block[0] = length; |
7656032b | 1625 | memcpy(&data.block[1], values, length); |
1da177e4 LT |
1626 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
1627 | I2C_SMBUS_WRITE,command, | |
1628 | I2C_SMBUS_BLOCK_DATA,&data); | |
1629 | } | |
c0564606 | 1630 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
1631 | |
1632 | /* Returns the number of read bytes */ | |
4b2643d7 JD |
1633 | s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, |
1634 | u8 length, u8 *values) | |
1da177e4 LT |
1635 | { |
1636 | union i2c_smbus_data data; | |
24a5bb7b | 1637 | int status; |
7656032b | 1638 | |
4b2643d7 JD |
1639 | if (length > I2C_SMBUS_BLOCK_MAX) |
1640 | length = I2C_SMBUS_BLOCK_MAX; | |
1641 | data.block[0] = length; | |
24a5bb7b DB |
1642 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1643 | I2C_SMBUS_READ, command, | |
1644 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1645 | if (status < 0) | |
1646 | return status; | |
7656032b JD |
1647 | |
1648 | memcpy(values, &data.block[1], data.block[0]); | |
1649 | return data.block[0]; | |
1da177e4 | 1650 | } |
c0564606 | 1651 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 1652 | |
21bbd691 | 1653 | s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1654 | u8 length, const u8 *values) |
21bbd691 JD |
1655 | { |
1656 | union i2c_smbus_data data; | |
1657 | ||
1658 | if (length > I2C_SMBUS_BLOCK_MAX) | |
1659 | length = I2C_SMBUS_BLOCK_MAX; | |
1660 | data.block[0] = length; | |
1661 | memcpy(data.block + 1, values, length); | |
1662 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1663 | I2C_SMBUS_WRITE, command, | |
1664 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1665 | } | |
c0564606 | 1666 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 1667 | |
438d6c2c | 1668 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 1669 | No checking of parameters is done! */ |
438d6c2c | 1670 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, |
1da177e4 | 1671 | unsigned short flags, |
438d6c2c | 1672 | char read_write, u8 command, int size, |
1da177e4 LT |
1673 | union i2c_smbus_data * data) |
1674 | { | |
1675 | /* So we need to generate a series of msgs. In the case of writing, we | |
1676 | need to use only one message; when reading, we need two. We initialize | |
1677 | most things with sane defaults, to keep the code below somewhat | |
1678 | simpler. */ | |
5c50d188 HI |
1679 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
1680 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
1da177e4 | 1681 | int num = read_write == I2C_SMBUS_READ?2:1; |
438d6c2c | 1682 | struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 }, |
1da177e4 LT |
1683 | { addr, flags | I2C_M_RD, 0, msgbuf1 } |
1684 | }; | |
1685 | int i; | |
421ef47b | 1686 | u8 partial_pec = 0; |
24a5bb7b | 1687 | int status; |
1da177e4 LT |
1688 | |
1689 | msgbuf0[0] = command; | |
1690 | switch(size) { | |
1691 | case I2C_SMBUS_QUICK: | |
1692 | msg[0].len = 0; | |
1693 | /* Special case: The read/write field is used as data */ | |
f29d2e02 RK |
1694 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
1695 | I2C_M_RD : 0); | |
1da177e4 LT |
1696 | num = 1; |
1697 | break; | |
1698 | case I2C_SMBUS_BYTE: | |
1699 | if (read_write == I2C_SMBUS_READ) { | |
1700 | /* Special case: only a read! */ | |
1701 | msg[0].flags = I2C_M_RD | flags; | |
1702 | num = 1; | |
1703 | } | |
1704 | break; | |
1705 | case I2C_SMBUS_BYTE_DATA: | |
1706 | if (read_write == I2C_SMBUS_READ) | |
1707 | msg[1].len = 1; | |
1708 | else { | |
1709 | msg[0].len = 2; | |
1710 | msgbuf0[1] = data->byte; | |
1711 | } | |
1712 | break; | |
1713 | case I2C_SMBUS_WORD_DATA: | |
1714 | if (read_write == I2C_SMBUS_READ) | |
1715 | msg[1].len = 2; | |
1716 | else { | |
1717 | msg[0].len=3; | |
1718 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1719 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1720 | } |
1721 | break; | |
1722 | case I2C_SMBUS_PROC_CALL: | |
1723 | num = 2; /* Special case */ | |
1724 | read_write = I2C_SMBUS_READ; | |
1725 | msg[0].len = 3; | |
1726 | msg[1].len = 2; | |
1727 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1728 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1729 | break; |
1730 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 1731 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
1732 | msg[1].flags |= I2C_M_RECV_LEN; |
1733 | msg[1].len = 1; /* block length will be added by | |
1734 | the underlying bus driver */ | |
1da177e4 LT |
1735 | } else { |
1736 | msg[0].len = data->block[0] + 2; | |
1737 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
1738 | dev_err(&adapter->dev, |
1739 | "Invalid block write size %d\n", | |
1740 | data->block[0]); | |
1741 | return -EINVAL; | |
1da177e4 | 1742 | } |
5c50d188 | 1743 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
1744 | msgbuf0[i] = data->block[i-1]; |
1745 | } | |
1746 | break; | |
1747 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
1748 | num = 2; /* Another special case */ |
1749 | read_write = I2C_SMBUS_READ; | |
1750 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
1751 | dev_err(&adapter->dev, |
1752 | "Invalid block write size %d\n", | |
209d27c3 | 1753 | data->block[0]); |
24a5bb7b | 1754 | return -EINVAL; |
209d27c3 JD |
1755 | } |
1756 | msg[0].len = data->block[0] + 2; | |
1757 | for (i = 1; i < msg[0].len; i++) | |
1758 | msgbuf0[i] = data->block[i-1]; | |
1759 | msg[1].flags |= I2C_M_RECV_LEN; | |
1760 | msg[1].len = 1; /* block length will be added by | |
1761 | the underlying bus driver */ | |
1762 | break; | |
1da177e4 LT |
1763 | case I2C_SMBUS_I2C_BLOCK_DATA: |
1764 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 1765 | msg[1].len = data->block[0]; |
1da177e4 LT |
1766 | } else { |
1767 | msg[0].len = data->block[0] + 1; | |
30dac746 | 1768 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
1769 | dev_err(&adapter->dev, |
1770 | "Invalid block write size %d\n", | |
1771 | data->block[0]); | |
1772 | return -EINVAL; | |
1da177e4 LT |
1773 | } |
1774 | for (i = 1; i <= data->block[0]; i++) | |
1775 | msgbuf0[i] = data->block[i]; | |
1776 | } | |
1777 | break; | |
1778 | default: | |
24a5bb7b DB |
1779 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
1780 | return -EOPNOTSUPP; | |
1da177e4 LT |
1781 | } |
1782 | ||
421ef47b JD |
1783 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
1784 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
1785 | if (i) { | |
1786 | /* Compute PEC if first message is a write */ | |
1787 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 1788 | if (num == 1) /* Write only */ |
421ef47b JD |
1789 | i2c_smbus_add_pec(&msg[0]); |
1790 | else /* Write followed by read */ | |
1791 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
1792 | } | |
1793 | /* Ask for PEC if last message is a read */ | |
1794 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 1795 | msg[num-1].len++; |
421ef47b JD |
1796 | } |
1797 | ||
24a5bb7b DB |
1798 | status = i2c_transfer(adapter, msg, num); |
1799 | if (status < 0) | |
1800 | return status; | |
1da177e4 | 1801 | |
421ef47b JD |
1802 | /* Check PEC if last message is a read */ |
1803 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
1804 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
1805 | if (status < 0) | |
1806 | return status; | |
421ef47b JD |
1807 | } |
1808 | ||
1da177e4 LT |
1809 | if (read_write == I2C_SMBUS_READ) |
1810 | switch(size) { | |
1811 | case I2C_SMBUS_BYTE: | |
1812 | data->byte = msgbuf0[0]; | |
1813 | break; | |
1814 | case I2C_SMBUS_BYTE_DATA: | |
1815 | data->byte = msgbuf1[0]; | |
1816 | break; | |
438d6c2c | 1817 | case I2C_SMBUS_WORD_DATA: |
1da177e4 LT |
1818 | case I2C_SMBUS_PROC_CALL: |
1819 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
1820 | break; | |
1821 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
4b2643d7 | 1822 | for (i = 0; i < data->block[0]; i++) |
1da177e4 LT |
1823 | data->block[i+1] = msgbuf1[i]; |
1824 | break; | |
209d27c3 JD |
1825 | case I2C_SMBUS_BLOCK_DATA: |
1826 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
1827 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
1828 | data->block[i] = msgbuf1[i]; | |
1829 | break; | |
1da177e4 LT |
1830 | } |
1831 | return 0; | |
1832 | } | |
1833 | ||
a1cdedac DB |
1834 | /** |
1835 | * i2c_smbus_xfer - execute SMBus protocol operations | |
1836 | * @adapter: Handle to I2C bus | |
1837 | * @addr: Address of SMBus slave on that bus | |
1838 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
1839 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
1840 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
1841 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
1842 | * @data: Data to be read or written | |
1843 | * | |
1844 | * This executes an SMBus protocol operation, and returns a negative | |
1845 | * errno code else zero on success. | |
1846 | */ | |
09b8ce0a | 1847 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
a1cdedac | 1848 | char read_write, u8 command, int protocol, |
09b8ce0a | 1849 | union i2c_smbus_data *data) |
1da177e4 | 1850 | { |
66b650f0 CW |
1851 | unsigned long orig_jiffies; |
1852 | int try; | |
1da177e4 | 1853 | s32 res; |
1da177e4 LT |
1854 | |
1855 | flags &= I2C_M_TEN | I2C_CLIENT_PEC; | |
1da177e4 LT |
1856 | |
1857 | if (adapter->algo->smbus_xfer) { | |
194684e5 | 1858 | rt_mutex_lock(&adapter->bus_lock); |
66b650f0 CW |
1859 | |
1860 | /* Retry automatically on arbitration loss */ | |
1861 | orig_jiffies = jiffies; | |
1862 | for (res = 0, try = 0; try <= adapter->retries; try++) { | |
1863 | res = adapter->algo->smbus_xfer(adapter, addr, flags, | |
1864 | read_write, command, | |
1865 | protocol, data); | |
1866 | if (res != -EAGAIN) | |
1867 | break; | |
1868 | if (time_after(jiffies, | |
1869 | orig_jiffies + adapter->timeout)) | |
1870 | break; | |
1871 | } | |
194684e5 | 1872 | rt_mutex_unlock(&adapter->bus_lock); |
1da177e4 LT |
1873 | } else |
1874 | res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write, | |
a1cdedac | 1875 | command, protocol, data); |
1da177e4 | 1876 | |
1da177e4 LT |
1877 | return res; |
1878 | } | |
1da177e4 | 1879 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
1880 | |
1881 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
1882 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
1883 | MODULE_LICENSE("GPL"); |