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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> | |
d052d1be | 32 | #include <linux/platform_device.h> |
b3585e4f | 33 | #include <linux/mutex.h> |
b8d6f45b | 34 | #include <linux/completion.h> |
cea443a8 MR |
35 | #include <linux/hardirq.h> |
36 | #include <linux/irqflags.h> | |
1da177e4 LT |
37 | #include <asm/uaccess.h> |
38 | ||
9c1600ed DB |
39 | #include "i2c-core.h" |
40 | ||
1da177e4 | 41 | |
caada32a | 42 | static DEFINE_MUTEX(core_lock); |
1da177e4 LT |
43 | static DEFINE_IDR(i2c_adapter_idr); |
44 | ||
4735c98f JD |
45 | #define is_newstyle_driver(d) ((d)->probe || (d)->remove || (d)->detect) |
46 | ||
47 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); | |
f37dd80a DB |
48 | |
49 | /* ------------------------------------------------------------------------- */ | |
50 | ||
d2653e92 JD |
51 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
52 | const struct i2c_client *client) | |
53 | { | |
54 | while (id->name[0]) { | |
55 | if (strcmp(client->name, id->name) == 0) | |
56 | return id; | |
57 | id++; | |
58 | } | |
59 | return NULL; | |
60 | } | |
61 | ||
1da177e4 LT |
62 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
63 | { | |
7b4fbc50 DB |
64 | struct i2c_client *client = to_i2c_client(dev); |
65 | struct i2c_driver *driver = to_i2c_driver(drv); | |
66 | ||
67 | /* make legacy i2c drivers bypass driver model probing entirely; | |
68 | * such drivers scan each i2c adapter/bus themselves. | |
69 | */ | |
a1d9e6e4 | 70 | if (!is_newstyle_driver(driver)) |
7b4fbc50 DB |
71 | return 0; |
72 | ||
d2653e92 JD |
73 | /* match on an id table if there is one */ |
74 | if (driver->id_table) | |
75 | return i2c_match_id(driver->id_table, client) != NULL; | |
76 | ||
eb8a7908 | 77 | return 0; |
1da177e4 LT |
78 | } |
79 | ||
7b4fbc50 DB |
80 | #ifdef CONFIG_HOTPLUG |
81 | ||
82 | /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ | |
7eff2e7a | 83 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 DB |
84 | { |
85 | struct i2c_client *client = to_i2c_client(dev); | |
7b4fbc50 DB |
86 | |
87 | /* by definition, legacy drivers can't hotplug */ | |
d2653e92 | 88 | if (dev->driver) |
7b4fbc50 DB |
89 | return 0; |
90 | ||
eb8a7908 JD |
91 | if (add_uevent_var(env, "MODALIAS=%s%s", |
92 | I2C_MODULE_PREFIX, client->name)) | |
93 | return -ENOMEM; | |
7b4fbc50 DB |
94 | dev_dbg(dev, "uevent\n"); |
95 | return 0; | |
96 | } | |
97 | ||
98 | #else | |
99 | #define i2c_device_uevent NULL | |
100 | #endif /* CONFIG_HOTPLUG */ | |
101 | ||
f37dd80a | 102 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 103 | { |
7b4fbc50 DB |
104 | struct i2c_client *client = to_i2c_client(dev); |
105 | struct i2c_driver *driver = to_i2c_driver(dev->driver); | |
50c3304a | 106 | int status; |
7b4fbc50 | 107 | |
e0457442 | 108 | if (!driver->probe || !driver->id_table) |
7b4fbc50 DB |
109 | return -ENODEV; |
110 | client->driver = driver; | |
ee35425c MP |
111 | if (!device_can_wakeup(&client->dev)) |
112 | device_init_wakeup(&client->dev, | |
113 | client->flags & I2C_CLIENT_WAKE); | |
7b4fbc50 | 114 | dev_dbg(dev, "probe\n"); |
d2653e92 | 115 | |
e0457442 | 116 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
50c3304a HV |
117 | if (status) |
118 | client->driver = NULL; | |
119 | return status; | |
f37dd80a | 120 | } |
1da177e4 | 121 | |
f37dd80a DB |
122 | static int i2c_device_remove(struct device *dev) |
123 | { | |
a1d9e6e4 DB |
124 | struct i2c_client *client = to_i2c_client(dev); |
125 | struct i2c_driver *driver; | |
126 | int status; | |
127 | ||
128 | if (!dev->driver) | |
129 | return 0; | |
130 | ||
131 | driver = to_i2c_driver(dev->driver); | |
132 | if (driver->remove) { | |
133 | dev_dbg(dev, "remove\n"); | |
134 | status = driver->remove(client); | |
135 | } else { | |
136 | dev->driver = NULL; | |
137 | status = 0; | |
138 | } | |
139 | if (status == 0) | |
140 | client->driver = NULL; | |
141 | return status; | |
1da177e4 LT |
142 | } |
143 | ||
f37dd80a | 144 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 145 | { |
f37dd80a DB |
146 | struct i2c_driver *driver; |
147 | ||
148 | if (!dev->driver) | |
149 | return; | |
150 | driver = to_i2c_driver(dev->driver); | |
151 | if (driver->shutdown) | |
152 | driver->shutdown(to_i2c_client(dev)); | |
1da177e4 LT |
153 | } |
154 | ||
09b8ce0a | 155 | static int i2c_device_suspend(struct device *dev, pm_message_t mesg) |
1da177e4 | 156 | { |
f37dd80a DB |
157 | struct i2c_driver *driver; |
158 | ||
159 | if (!dev->driver) | |
160 | return 0; | |
161 | driver = to_i2c_driver(dev->driver); | |
162 | if (!driver->suspend) | |
163 | return 0; | |
164 | return driver->suspend(to_i2c_client(dev), mesg); | |
1da177e4 LT |
165 | } |
166 | ||
09b8ce0a | 167 | static int i2c_device_resume(struct device *dev) |
1da177e4 | 168 | { |
f37dd80a DB |
169 | struct i2c_driver *driver; |
170 | ||
171 | if (!dev->driver) | |
172 | return 0; | |
173 | driver = to_i2c_driver(dev->driver); | |
174 | if (!driver->resume) | |
175 | return 0; | |
176 | return driver->resume(to_i2c_client(dev)); | |
1da177e4 LT |
177 | } |
178 | ||
7b4fbc50 DB |
179 | static void i2c_client_release(struct device *dev) |
180 | { | |
181 | struct i2c_client *client = to_i2c_client(dev); | |
182 | complete(&client->released); | |
183 | } | |
184 | ||
9c1600ed DB |
185 | static void i2c_client_dev_release(struct device *dev) |
186 | { | |
187 | kfree(to_i2c_client(dev)); | |
188 | } | |
189 | ||
09b8ce0a ZX |
190 | static ssize_t |
191 | show_client_name(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
192 | { |
193 | struct i2c_client *client = to_i2c_client(dev); | |
194 | return sprintf(buf, "%s\n", client->name); | |
195 | } | |
196 | ||
09b8ce0a ZX |
197 | static ssize_t |
198 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
199 | { |
200 | struct i2c_client *client = to_i2c_client(dev); | |
eb8a7908 | 201 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
202 | } |
203 | ||
204 | static struct device_attribute i2c_dev_attrs[] = { | |
205 | __ATTR(name, S_IRUGO, show_client_name, NULL), | |
206 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ | |
207 | __ATTR(modalias, S_IRUGO, show_modalias, NULL), | |
208 | { }, | |
209 | }; | |
210 | ||
e9ca9eb9 | 211 | struct bus_type i2c_bus_type = { |
f37dd80a | 212 | .name = "i2c", |
7b4fbc50 | 213 | .dev_attrs = i2c_dev_attrs, |
f37dd80a | 214 | .match = i2c_device_match, |
7b4fbc50 | 215 | .uevent = i2c_device_uevent, |
f37dd80a DB |
216 | .probe = i2c_device_probe, |
217 | .remove = i2c_device_remove, | |
218 | .shutdown = i2c_device_shutdown, | |
219 | .suspend = i2c_device_suspend, | |
220 | .resume = i2c_device_resume, | |
b864c7d5 | 221 | }; |
e9ca9eb9 | 222 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 223 | |
9b766b81 DB |
224 | |
225 | /** | |
226 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
227 | * @dev: device, probably from some driver model iterator | |
228 | * | |
229 | * When traversing the driver model tree, perhaps using driver model | |
230 | * iterators like @device_for_each_child(), you can't assume very much | |
231 | * about the nodes you find. Use this function to avoid oopses caused | |
232 | * by wrongly treating some non-I2C device as an i2c_client. | |
233 | */ | |
234 | struct i2c_client *i2c_verify_client(struct device *dev) | |
235 | { | |
236 | return (dev->bus == &i2c_bus_type) | |
237 | ? to_i2c_client(dev) | |
238 | : NULL; | |
239 | } | |
240 | EXPORT_SYMBOL(i2c_verify_client); | |
241 | ||
242 | ||
9c1600ed DB |
243 | /** |
244 | * i2c_new_device - instantiate an i2c device for use with a new style driver | |
245 | * @adap: the adapter managing the device | |
246 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 247 | * Context: can sleep |
9c1600ed DB |
248 | * |
249 | * Create a device to work with a new style i2c driver, where binding is | |
250 | * handled through driver model probe()/remove() methods. This call is not | |
251 | * appropriate for use by mainboad initialization logic, which usually runs | |
252 | * during an arch_initcall() long before any i2c_adapter could exist. | |
253 | * | |
254 | * This returns the new i2c client, which may be saved for later use with | |
255 | * i2c_unregister_device(); or NULL to indicate an error. | |
256 | */ | |
257 | struct i2c_client * | |
258 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
259 | { | |
260 | struct i2c_client *client; | |
261 | int status; | |
262 | ||
263 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
264 | if (!client) | |
265 | return NULL; | |
266 | ||
267 | client->adapter = adap; | |
268 | ||
269 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 270 | |
11f1f2af AV |
271 | if (info->archdata) |
272 | client->dev.archdata = *info->archdata; | |
273 | ||
ee35425c | 274 | client->flags = info->flags; |
9c1600ed DB |
275 | client->addr = info->addr; |
276 | client->irq = info->irq; | |
277 | ||
9c1600ed DB |
278 | strlcpy(client->name, info->type, sizeof(client->name)); |
279 | ||
280 | /* a new style driver may be bound to this device when we | |
281 | * return from this function, or any later moment (e.g. maybe | |
282 | * hotplugging will load the driver module). and the device | |
283 | * refcount model is the standard driver model one. | |
284 | */ | |
285 | status = i2c_attach_client(client); | |
286 | if (status < 0) { | |
287 | kfree(client); | |
288 | client = NULL; | |
289 | } | |
290 | return client; | |
291 | } | |
292 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
293 | ||
294 | ||
295 | /** | |
296 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
297 | * @client: value returned from i2c_new_device() | |
d64f73be | 298 | * Context: can sleep |
9c1600ed DB |
299 | */ |
300 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 DB |
301 | { |
302 | struct i2c_adapter *adapter = client->adapter; | |
303 | struct i2c_driver *driver = client->driver; | |
304 | ||
305 | if (driver && !is_newstyle_driver(driver)) { | |
306 | dev_err(&client->dev, "can't unregister devices " | |
307 | "with legacy drivers\n"); | |
308 | WARN_ON(1); | |
309 | return; | |
310 | } | |
311 | ||
8508159e JD |
312 | if (adapter->client_unregister) { |
313 | if (adapter->client_unregister(client)) { | |
314 | dev_warn(&client->dev, | |
315 | "client_unregister [%s] failed\n", | |
316 | client->name); | |
317 | } | |
318 | } | |
319 | ||
a1d9e6e4 DB |
320 | mutex_lock(&adapter->clist_lock); |
321 | list_del(&client->list); | |
322 | mutex_unlock(&adapter->clist_lock); | |
323 | ||
324 | device_unregister(&client->dev); | |
325 | } | |
9c1600ed | 326 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
327 | |
328 | ||
60b129d7 JD |
329 | static const struct i2c_device_id dummy_id[] = { |
330 | { "dummy", 0 }, | |
331 | { }, | |
332 | }; | |
333 | ||
d2653e92 JD |
334 | static int dummy_probe(struct i2c_client *client, |
335 | const struct i2c_device_id *id) | |
336 | { | |
337 | return 0; | |
338 | } | |
339 | ||
340 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
341 | { |
342 | return 0; | |
343 | } | |
344 | ||
345 | static struct i2c_driver dummy_driver = { | |
346 | .driver.name = "dummy", | |
d2653e92 JD |
347 | .probe = dummy_probe, |
348 | .remove = dummy_remove, | |
60b129d7 | 349 | .id_table = dummy_id, |
e9f1373b DB |
350 | }; |
351 | ||
352 | /** | |
353 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
354 | * @adapter: the adapter managing the device | |
355 | * @address: seven bit address to be used | |
e9f1373b DB |
356 | * Context: can sleep |
357 | * | |
358 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
359 | * with devices that consume multiple addresses. Examples of such chips | |
360 | * include various EEPROMS (like 24c04 and 24c08 models). | |
361 | * | |
362 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
363 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
364 | * And second, this prevents the specified address from being bound to a | |
365 | * different driver. | |
366 | * | |
367 | * This returns the new i2c client, which should be saved for later use with | |
368 | * i2c_unregister_device(); or NULL to indicate an error. | |
369 | */ | |
09b8ce0a | 370 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
371 | { |
372 | struct i2c_board_info info = { | |
60b129d7 | 373 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
374 | }; |
375 | ||
e9f1373b DB |
376 | return i2c_new_device(adapter, &info); |
377 | } | |
378 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
379 | ||
f37dd80a DB |
380 | /* ------------------------------------------------------------------------- */ |
381 | ||
16ffadfc DB |
382 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
383 | ||
83eaaed0 | 384 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 385 | { |
ef2c8321 | 386 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
387 | complete(&adap->dev_released); |
388 | } | |
389 | ||
16ffadfc DB |
390 | static ssize_t |
391 | show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf) | |
392 | { | |
ef2c8321 | 393 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
16ffadfc DB |
394 | return sprintf(buf, "%s\n", adap->name); |
395 | } | |
b119dc3f | 396 | |
16ffadfc DB |
397 | static struct device_attribute i2c_adapter_attrs[] = { |
398 | __ATTR(name, S_IRUGO, show_adapter_name, NULL), | |
399 | { }, | |
400 | }; | |
b119dc3f | 401 | |
83eaaed0 | 402 | static struct class i2c_adapter_class = { |
b119dc3f DB |
403 | .owner = THIS_MODULE, |
404 | .name = "i2c-adapter", | |
16ffadfc | 405 | .dev_attrs = i2c_adapter_attrs, |
1da177e4 LT |
406 | }; |
407 | ||
9c1600ed DB |
408 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
409 | { | |
410 | struct i2c_devinfo *devinfo; | |
411 | ||
412 | mutex_lock(&__i2c_board_lock); | |
413 | list_for_each_entry(devinfo, &__i2c_board_list, list) { | |
414 | if (devinfo->busnum == adapter->nr | |
415 | && !i2c_new_device(adapter, | |
416 | &devinfo->board_info)) | |
09b8ce0a ZX |
417 | dev_err(&adapter->dev, |
418 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
419 | devinfo->board_info.addr); |
420 | } | |
421 | mutex_unlock(&__i2c_board_lock); | |
422 | } | |
423 | ||
026526f5 JD |
424 | static int i2c_do_add_adapter(struct device_driver *d, void *data) |
425 | { | |
426 | struct i2c_driver *driver = to_i2c_driver(d); | |
427 | struct i2c_adapter *adap = data; | |
428 | ||
4735c98f JD |
429 | /* Detect supported devices on that bus, and instantiate them */ |
430 | i2c_detect(adap, driver); | |
431 | ||
432 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 JD |
433 | if (driver->attach_adapter) { |
434 | /* We ignore the return code; if it fails, too bad */ | |
435 | driver->attach_adapter(adap); | |
436 | } | |
437 | return 0; | |
438 | } | |
439 | ||
6e13e641 | 440 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 441 | { |
026526f5 | 442 | int res = 0, dummy; |
1da177e4 | 443 | |
1d0b19c9 DB |
444 | /* Can't register until after driver model init */ |
445 | if (unlikely(WARN_ON(!i2c_bus_type.p))) | |
446 | return -EAGAIN; | |
447 | ||
5c085d36 IM |
448 | mutex_init(&adap->bus_lock); |
449 | mutex_init(&adap->clist_lock); | |
1da177e4 LT |
450 | INIT_LIST_HEAD(&adap->clients); |
451 | ||
caada32a | 452 | mutex_lock(&core_lock); |
6e13e641 | 453 | |
1da177e4 LT |
454 | /* Add the adapter to the driver core. |
455 | * If the parent pointer is not set up, | |
456 | * we add this adapter to the host bus. | |
457 | */ | |
b119dc3f | 458 | if (adap->dev.parent == NULL) { |
1da177e4 | 459 | adap->dev.parent = &platform_bus; |
fe2c8d51 JD |
460 | pr_debug("I2C adapter driver [%s] forgot to specify " |
461 | "physical device\n", adap->name); | |
b119dc3f | 462 | } |
8fcfef6e JD |
463 | |
464 | /* Set default timeout to 1 second if not already set */ | |
465 | if (adap->timeout == 0) | |
466 | adap->timeout = HZ; | |
467 | ||
27d9c183 | 468 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
1da177e4 | 469 | adap->dev.release = &i2c_adapter_dev_release; |
fccb56e4 | 470 | adap->dev.class = &i2c_adapter_class; |
b119c6c9 JD |
471 | res = device_register(&adap->dev); |
472 | if (res) | |
473 | goto out_list; | |
1da177e4 | 474 | |
b6d7b3d1 JD |
475 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
476 | ||
6e13e641 DB |
477 | /* create pre-declared device nodes for new-style drivers */ |
478 | if (adap->nr < __i2c_first_dynamic_bus_num) | |
479 | i2c_scan_static_board_info(adap); | |
480 | ||
4735c98f | 481 | /* Notify drivers */ |
026526f5 JD |
482 | dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
483 | i2c_do_add_adapter); | |
1da177e4 | 484 | |
1da177e4 | 485 | out_unlock: |
caada32a | 486 | mutex_unlock(&core_lock); |
1da177e4 | 487 | return res; |
b119c6c9 | 488 | |
b119c6c9 | 489 | out_list: |
b119c6c9 JD |
490 | idr_remove(&i2c_adapter_idr, adap->nr); |
491 | goto out_unlock; | |
1da177e4 LT |
492 | } |
493 | ||
6e13e641 DB |
494 | /** |
495 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
496 | * @adapter: the adapter to add | |
d64f73be | 497 | * Context: can sleep |
6e13e641 DB |
498 | * |
499 | * This routine is used to declare an I2C adapter when its bus number | |
500 | * doesn't matter. Examples: for I2C adapters dynamically added by | |
501 | * USB links or PCI plugin cards. | |
502 | * | |
503 | * When this returns zero, a new bus number was allocated and stored | |
504 | * in adap->nr, and the specified adapter became available for clients. | |
505 | * Otherwise, a negative errno value is returned. | |
506 | */ | |
507 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
508 | { | |
509 | int id, res = 0; | |
510 | ||
511 | retry: | |
512 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
513 | return -ENOMEM; | |
514 | ||
caada32a | 515 | mutex_lock(&core_lock); |
6e13e641 DB |
516 | /* "above" here means "above or equal to", sigh */ |
517 | res = idr_get_new_above(&i2c_adapter_idr, adapter, | |
518 | __i2c_first_dynamic_bus_num, &id); | |
caada32a | 519 | mutex_unlock(&core_lock); |
6e13e641 DB |
520 | |
521 | if (res < 0) { | |
522 | if (res == -EAGAIN) | |
523 | goto retry; | |
524 | return res; | |
525 | } | |
526 | ||
527 | adapter->nr = id; | |
528 | return i2c_register_adapter(adapter); | |
529 | } | |
530 | EXPORT_SYMBOL(i2c_add_adapter); | |
531 | ||
532 | /** | |
533 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
534 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 535 | * Context: can sleep |
6e13e641 DB |
536 | * |
537 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
538 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
539 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
540 | * is used to properly configure I2C devices. |
541 | * | |
542 | * If no devices have pre-been declared for this bus, then be sure to | |
543 | * register the adapter before any dynamically allocated ones. Otherwise | |
544 | * the required bus ID may not be available. | |
545 | * | |
546 | * When this returns zero, the specified adapter became available for | |
547 | * clients using the bus number provided in adap->nr. Also, the table | |
548 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
549 | * and the appropriate driver model device nodes are created. Otherwise, a | |
550 | * negative errno value is returned. | |
551 | */ | |
552 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
553 | { | |
554 | int id; | |
555 | int status; | |
556 | ||
557 | if (adap->nr & ~MAX_ID_MASK) | |
558 | return -EINVAL; | |
559 | ||
560 | retry: | |
561 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
562 | return -ENOMEM; | |
563 | ||
caada32a | 564 | mutex_lock(&core_lock); |
6e13e641 DB |
565 | /* "above" here means "above or equal to", sigh; |
566 | * we need the "equal to" result to force the result | |
567 | */ | |
568 | status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id); | |
569 | if (status == 0 && id != adap->nr) { | |
570 | status = -EBUSY; | |
571 | idr_remove(&i2c_adapter_idr, id); | |
572 | } | |
caada32a | 573 | mutex_unlock(&core_lock); |
6e13e641 DB |
574 | if (status == -EAGAIN) |
575 | goto retry; | |
576 | ||
577 | if (status == 0) | |
578 | status = i2c_register_adapter(adap); | |
579 | return status; | |
580 | } | |
581 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
582 | ||
026526f5 JD |
583 | static int i2c_do_del_adapter(struct device_driver *d, void *data) |
584 | { | |
585 | struct i2c_driver *driver = to_i2c_driver(d); | |
586 | struct i2c_adapter *adapter = data; | |
4735c98f | 587 | struct i2c_client *client, *_n; |
026526f5 JD |
588 | int res; |
589 | ||
acec211c JD |
590 | /* Remove the devices we created ourselves as the result of hardware |
591 | * probing (using a driver's detect method) */ | |
4735c98f JD |
592 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
593 | if (client->adapter == adapter) { | |
594 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
595 | client->name, client->addr); | |
596 | list_del(&client->detected); | |
597 | i2c_unregister_device(client); | |
598 | } | |
599 | } | |
600 | ||
026526f5 JD |
601 | if (!driver->detach_adapter) |
602 | return 0; | |
603 | res = driver->detach_adapter(adapter); | |
604 | if (res) | |
605 | dev_err(&adapter->dev, "detach_adapter failed (%d) " | |
606 | "for driver [%s]\n", res, driver->driver.name); | |
607 | return res; | |
608 | } | |
609 | ||
d64f73be DB |
610 | /** |
611 | * i2c_del_adapter - unregister I2C adapter | |
612 | * @adap: the adapter being unregistered | |
613 | * Context: can sleep | |
614 | * | |
615 | * This unregisters an I2C adapter which was previously registered | |
616 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
617 | */ | |
1da177e4 LT |
618 | int i2c_del_adapter(struct i2c_adapter *adap) |
619 | { | |
6a03cd93 | 620 | struct i2c_client *client, *_n; |
1da177e4 LT |
621 | int res = 0; |
622 | ||
caada32a | 623 | mutex_lock(&core_lock); |
1da177e4 LT |
624 | |
625 | /* First make sure that this adapter was ever added */ | |
87c6c229 | 626 | if (idr_find(&i2c_adapter_idr, adap->nr) != adap) { |
b6d7b3d1 JD |
627 | pr_debug("i2c-core: attempting to delete unregistered " |
628 | "adapter [%s]\n", adap->name); | |
1da177e4 LT |
629 | res = -EINVAL; |
630 | goto out_unlock; | |
631 | } | |
632 | ||
026526f5 JD |
633 | /* Tell drivers about this removal */ |
634 | res = bus_for_each_drv(&i2c_bus_type, NULL, adap, | |
635 | i2c_do_del_adapter); | |
636 | if (res) | |
637 | goto out_unlock; | |
1da177e4 LT |
638 | |
639 | /* detach any active clients. This must be done first, because | |
a551acc2 | 640 | * it can fail; in which case we give up. */ |
79b93e13 | 641 | list_for_each_entry_safe_reverse(client, _n, &adap->clients, list) { |
a1d9e6e4 DB |
642 | struct i2c_driver *driver; |
643 | ||
a1d9e6e4 DB |
644 | driver = client->driver; |
645 | ||
646 | /* new style, follow standard driver model */ | |
647 | if (!driver || is_newstyle_driver(driver)) { | |
648 | i2c_unregister_device(client); | |
649 | continue; | |
650 | } | |
1da177e4 | 651 | |
a1d9e6e4 DB |
652 | /* legacy drivers create and remove clients themselves */ |
653 | if ((res = driver->detach_client(client))) { | |
b6d7b3d1 JD |
654 | dev_err(&adap->dev, "detach_client failed for client " |
655 | "[%s] at address 0x%02x\n", client->name, | |
1da177e4 LT |
656 | client->addr); |
657 | goto out_unlock; | |
658 | } | |
659 | } | |
660 | ||
661 | /* clean up the sysfs representation */ | |
662 | init_completion(&adap->dev_released); | |
1da177e4 | 663 | device_unregister(&adap->dev); |
1da177e4 LT |
664 | |
665 | /* wait for sysfs to drop all references */ | |
666 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 667 | |
6e13e641 | 668 | /* free bus id */ |
1da177e4 LT |
669 | idr_remove(&i2c_adapter_idr, adap->nr); |
670 | ||
b6d7b3d1 | 671 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); |
1da177e4 | 672 | |
bd4bc3db JD |
673 | /* Clear the device structure in case this adapter is ever going to be |
674 | added again */ | |
675 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
676 | ||
1da177e4 | 677 | out_unlock: |
caada32a | 678 | mutex_unlock(&core_lock); |
1da177e4 LT |
679 | return res; |
680 | } | |
c0564606 | 681 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 LT |
682 | |
683 | ||
7b4fbc50 DB |
684 | /* ------------------------------------------------------------------------- */ |
685 | ||
7f101a97 DY |
686 | static int __attach_adapter(struct device *dev, void *data) |
687 | { | |
688 | struct i2c_adapter *adapter = to_i2c_adapter(dev); | |
689 | struct i2c_driver *driver = data; | |
690 | ||
4735c98f JD |
691 | i2c_detect(adapter, driver); |
692 | ||
693 | /* Legacy drivers scan i2c busses directly */ | |
694 | if (driver->attach_adapter) | |
695 | driver->attach_adapter(adapter); | |
7f101a97 DY |
696 | |
697 | return 0; | |
698 | } | |
699 | ||
7b4fbc50 DB |
700 | /* |
701 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
702 | * i2c slave chips, on a bus instance associated with some i2c_adapter. There | |
703 | * are two models for binding the driver to its device: "new style" drivers | |
704 | * follow the standard Linux driver model and just respond to probe() calls | |
705 | * issued if the driver core sees they match(); "legacy" drivers create device | |
706 | * nodes themselves. | |
1da177e4 LT |
707 | */ |
708 | ||
de59cf9e | 709 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 710 | { |
7eebcb7c | 711 | int res; |
1da177e4 | 712 | |
1d0b19c9 DB |
713 | /* Can't register until after driver model init */ |
714 | if (unlikely(WARN_ON(!i2c_bus_type.p))) | |
715 | return -EAGAIN; | |
716 | ||
7b4fbc50 | 717 | /* new style driver methods can't mix with legacy ones */ |
a1d9e6e4 | 718 | if (is_newstyle_driver(driver)) { |
93529869 | 719 | if (driver->detach_adapter || driver->detach_client) { |
7b4fbc50 DB |
720 | printk(KERN_WARNING |
721 | "i2c-core: driver [%s] is confused\n", | |
722 | driver->driver.name); | |
723 | return -EINVAL; | |
724 | } | |
725 | } | |
726 | ||
1da177e4 | 727 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 728 | driver->driver.owner = owner; |
1da177e4 | 729 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 730 | |
6e13e641 DB |
731 | /* for new style drivers, when registration returns the driver core |
732 | * will have called probe() for all matching-but-unbound devices. | |
733 | */ | |
1da177e4 LT |
734 | res = driver_register(&driver->driver); |
735 | if (res) | |
7eebcb7c | 736 | return res; |
438d6c2c | 737 | |
caada32a | 738 | mutex_lock(&core_lock); |
7eebcb7c | 739 | |
35d8b2e6 | 740 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 741 | |
4735c98f JD |
742 | INIT_LIST_HEAD(&driver->clients); |
743 | /* Walk the adapters that are already present */ | |
93562b53 GKH |
744 | class_for_each_device(&i2c_adapter_class, NULL, driver, |
745 | __attach_adapter); | |
4ad4eac6 | 746 | |
7f101a97 DY |
747 | mutex_unlock(&core_lock); |
748 | return 0; | |
749 | } | |
750 | EXPORT_SYMBOL(i2c_register_driver); | |
751 | ||
752 | static int __detach_adapter(struct device *dev, void *data) | |
753 | { | |
754 | struct i2c_adapter *adapter = to_i2c_adapter(dev); | |
755 | struct i2c_driver *driver = data; | |
4735c98f JD |
756 | struct i2c_client *client, *_n; |
757 | ||
acec211c JD |
758 | /* Remove the devices we created ourselves as the result of hardware |
759 | * probing (using a driver's detect method) */ | |
4735c98f JD |
760 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
761 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
762 | client->name, client->addr); | |
763 | list_del(&client->detected); | |
764 | i2c_unregister_device(client); | |
765 | } | |
766 | ||
767 | if (is_newstyle_driver(driver)) | |
768 | return 0; | |
7f101a97 DY |
769 | |
770 | /* Have a look at each adapter, if clients of this driver are still | |
771 | * attached. If so, detach them to be able to kill the driver | |
772 | * afterwards. | |
773 | */ | |
774 | if (driver->detach_adapter) { | |
775 | if (driver->detach_adapter(adapter)) | |
776 | dev_err(&adapter->dev, | |
777 | "detach_adapter failed for driver [%s]\n", | |
778 | driver->driver.name); | |
779 | } else { | |
6a03cd93 | 780 | struct i2c_client *client, *_n; |
7f101a97 | 781 | |
6a03cd93 | 782 | list_for_each_entry_safe(client, _n, &adapter->clients, list) { |
7f101a97 DY |
783 | if (client->driver != driver) |
784 | continue; | |
785 | dev_dbg(&adapter->dev, | |
786 | "detaching client [%s] at 0x%02x\n", | |
787 | client->name, client->addr); | |
788 | if (driver->detach_client(client)) | |
789 | dev_err(&adapter->dev, "detach_client " | |
790 | "failed for client [%s] at 0x%02x\n", | |
791 | client->name, client->addr); | |
1da177e4 LT |
792 | } |
793 | } | |
794 | ||
7eebcb7c | 795 | return 0; |
1da177e4 LT |
796 | } |
797 | ||
a1d9e6e4 DB |
798 | /** |
799 | * i2c_del_driver - unregister I2C driver | |
800 | * @driver: the driver being unregistered | |
d64f73be | 801 | * Context: can sleep |
a1d9e6e4 | 802 | */ |
b3e82096 | 803 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 804 | { |
caada32a | 805 | mutex_lock(&core_lock); |
1da177e4 | 806 | |
93562b53 GKH |
807 | class_for_each_device(&i2c_adapter_class, NULL, driver, |
808 | __detach_adapter); | |
1da177e4 LT |
809 | |
810 | driver_unregister(&driver->driver); | |
35d8b2e6 | 811 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 812 | |
caada32a | 813 | mutex_unlock(&core_lock); |
1da177e4 | 814 | } |
c0564606 | 815 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 816 | |
7b4fbc50 DB |
817 | /* ------------------------------------------------------------------------- */ |
818 | ||
9b766b81 | 819 | static int __i2c_check_addr(struct device *dev, void *addrp) |
1da177e4 | 820 | { |
9b766b81 DB |
821 | struct i2c_client *client = i2c_verify_client(dev); |
822 | int addr = *(int *)addrp; | |
1da177e4 | 823 | |
9b766b81 DB |
824 | if (client && client->addr == addr) |
825 | return -EBUSY; | |
1da177e4 LT |
826 | return 0; |
827 | } | |
828 | ||
5e31c2bd | 829 | static int i2c_check_addr(struct i2c_adapter *adapter, int addr) |
1da177e4 | 830 | { |
9b766b81 | 831 | return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr); |
1da177e4 LT |
832 | } |
833 | ||
834 | int i2c_attach_client(struct i2c_client *client) | |
835 | { | |
836 | struct i2c_adapter *adapter = client->adapter; | |
c1159f9e JD |
837 | int res; |
838 | ||
839 | /* Check for address business */ | |
840 | res = i2c_check_addr(adapter, client->addr); | |
841 | if (res) | |
842 | return res; | |
1da177e4 | 843 | |
1da177e4 | 844 | client->dev.parent = &client->adapter->dev; |
1da177e4 | 845 | client->dev.bus = &i2c_bus_type; |
9c1600ed DB |
846 | |
847 | if (client->driver) | |
848 | client->dev.driver = &client->driver->driver; | |
849 | ||
de81d2aa | 850 | if (client->driver && !is_newstyle_driver(client->driver)) { |
9c1600ed | 851 | client->dev.release = i2c_client_release; |
f67f129e | 852 | dev_set_uevent_suppress(&client->dev, 1); |
de81d2aa | 853 | } else |
9c1600ed | 854 | client->dev.release = i2c_client_dev_release; |
438d6c2c | 855 | |
27d9c183 KS |
856 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adapter), |
857 | client->addr); | |
b119c6c9 JD |
858 | res = device_register(&client->dev); |
859 | if (res) | |
86ec5ec8 DB |
860 | goto out_err; |
861 | ||
862 | mutex_lock(&adapter->clist_lock); | |
863 | list_add_tail(&client->list, &adapter->clients); | |
b119c6c9 | 864 | mutex_unlock(&adapter->clist_lock); |
77ed74da | 865 | |
86ec5ec8 | 866 | dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n", |
27d9c183 | 867 | client->name, dev_name(&client->dev)); |
86ec5ec8 | 868 | |
77ed74da JD |
869 | if (adapter->client_register) { |
870 | if (adapter->client_register(client)) { | |
871 | dev_dbg(&adapter->dev, "client_register " | |
872 | "failed for client [%s] at 0x%02x\n", | |
873 | client->name, client->addr); | |
874 | } | |
875 | } | |
876 | ||
877 | return 0; | |
b119c6c9 | 878 | |
86ec5ec8 | 879 | out_err: |
b119c6c9 JD |
880 | dev_err(&adapter->dev, "Failed to attach i2c client %s at 0x%02x " |
881 | "(%d)\n", client->name, client->addr, res); | |
77ed74da | 882 | return res; |
1da177e4 | 883 | } |
c0564606 | 884 | EXPORT_SYMBOL(i2c_attach_client); |
1da177e4 LT |
885 | |
886 | int i2c_detach_client(struct i2c_client *client) | |
887 | { | |
888 | struct i2c_adapter *adapter = client->adapter; | |
889 | int res = 0; | |
438d6c2c | 890 | |
1da177e4 LT |
891 | if (adapter->client_unregister) { |
892 | res = adapter->client_unregister(client); | |
893 | if (res) { | |
894 | dev_err(&client->dev, | |
86749e85 JD |
895 | "client_unregister [%s] failed, " |
896 | "client not detached\n", client->name); | |
1da177e4 LT |
897 | goto out; |
898 | } | |
899 | } | |
900 | ||
5c085d36 | 901 | mutex_lock(&adapter->clist_lock); |
1da177e4 | 902 | list_del(&client->list); |
9ddced16 JD |
903 | mutex_unlock(&adapter->clist_lock); |
904 | ||
1da177e4 | 905 | init_completion(&client->released); |
1da177e4 | 906 | device_unregister(&client->dev); |
1da177e4 LT |
907 | wait_for_completion(&client->released); |
908 | ||
909 | out: | |
910 | return res; | |
911 | } | |
c0564606 | 912 | EXPORT_SYMBOL(i2c_detach_client); |
1da177e4 | 913 | |
e48d3319 JD |
914 | /** |
915 | * i2c_use_client - increments the reference count of the i2c client structure | |
916 | * @client: the client being referenced | |
917 | * | |
918 | * Each live reference to a client should be refcounted. The driver model does | |
919 | * that automatically as part of driver binding, so that most drivers don't | |
920 | * need to do this explicitly: they hold a reference until they're unbound | |
921 | * from the device. | |
922 | * | |
923 | * A pointer to the client with the incremented reference counter is returned. | |
924 | */ | |
925 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 926 | { |
6ea438ec DB |
927 | if (client && get_device(&client->dev)) |
928 | return client; | |
929 | return NULL; | |
1da177e4 | 930 | } |
c0564606 | 931 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 932 | |
e48d3319 JD |
933 | /** |
934 | * i2c_release_client - release a use of the i2c client structure | |
935 | * @client: the client being no longer referenced | |
936 | * | |
937 | * Must be called when a user of a client is finished with it. | |
938 | */ | |
939 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 940 | { |
6ea438ec DB |
941 | if (client) |
942 | put_device(&client->dev); | |
1da177e4 | 943 | } |
c0564606 | 944 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 945 | |
9b766b81 DB |
946 | struct i2c_cmd_arg { |
947 | unsigned cmd; | |
948 | void *arg; | |
949 | }; | |
950 | ||
951 | static int i2c_cmd(struct device *dev, void *_arg) | |
952 | { | |
953 | struct i2c_client *client = i2c_verify_client(dev); | |
954 | struct i2c_cmd_arg *arg = _arg; | |
955 | ||
956 | if (client && client->driver && client->driver->command) | |
957 | client->driver->command(client, arg->cmd, arg->arg); | |
958 | return 0; | |
959 | } | |
960 | ||
1da177e4 LT |
961 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
962 | { | |
9b766b81 | 963 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 964 | |
9b766b81 DB |
965 | cmd_arg.cmd = cmd; |
966 | cmd_arg.arg = arg; | |
967 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 968 | } |
c0564606 | 969 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
970 | |
971 | static int __init i2c_init(void) | |
972 | { | |
973 | int retval; | |
974 | ||
975 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
976 | if (retval) |
977 | return retval; | |
e9f1373b DB |
978 | retval = class_register(&i2c_adapter_class); |
979 | if (retval) | |
980 | goto bus_err; | |
981 | retval = i2c_add_driver(&dummy_driver); | |
982 | if (retval) | |
983 | goto class_err; | |
984 | return 0; | |
985 | ||
986 | class_err: | |
987 | class_unregister(&i2c_adapter_class); | |
988 | bus_err: | |
989 | bus_unregister(&i2c_bus_type); | |
990 | return retval; | |
1da177e4 LT |
991 | } |
992 | ||
993 | static void __exit i2c_exit(void) | |
994 | { | |
e9f1373b | 995 | i2c_del_driver(&dummy_driver); |
1da177e4 | 996 | class_unregister(&i2c_adapter_class); |
1da177e4 LT |
997 | bus_unregister(&i2c_bus_type); |
998 | } | |
999 | ||
a10f9e7c DB |
1000 | /* We must initialize early, because some subsystems register i2c drivers |
1001 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1002 | */ | |
1003 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1004 | module_exit(i2c_exit); |
1005 | ||
1006 | /* ---------------------------------------------------- | |
1007 | * the functional interface to the i2c busses. | |
1008 | * ---------------------------------------------------- | |
1009 | */ | |
1010 | ||
a1cdedac DB |
1011 | /** |
1012 | * i2c_transfer - execute a single or combined I2C message | |
1013 | * @adap: Handle to I2C bus | |
1014 | * @msgs: One or more messages to execute before STOP is issued to | |
1015 | * terminate the operation; each message begins with a START. | |
1016 | * @num: Number of messages to be executed. | |
1017 | * | |
1018 | * Returns negative errno, else the number of messages executed. | |
1019 | * | |
1020 | * Note that there is no requirement that each message be sent to | |
1021 | * the same slave address, although that is the most common model. | |
1022 | */ | |
09b8ce0a | 1023 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 LT |
1024 | { |
1025 | int ret; | |
1026 | ||
a1cdedac DB |
1027 | /* REVISIT the fault reporting model here is weak: |
1028 | * | |
1029 | * - When we get an error after receiving N bytes from a slave, | |
1030 | * there is no way to report "N". | |
1031 | * | |
1032 | * - When we get a NAK after transmitting N bytes to a slave, | |
1033 | * there is no way to report "N" ... or to let the master | |
1034 | * continue executing the rest of this combined message, if | |
1035 | * that's the appropriate response. | |
1036 | * | |
1037 | * - When for example "num" is two and we successfully complete | |
1038 | * the first message but get an error part way through the | |
1039 | * second, it's unclear whether that should be reported as | |
1040 | * one (discarding status on the second message) or errno | |
1041 | * (discarding status on the first one). | |
1042 | */ | |
1043 | ||
1da177e4 LT |
1044 | if (adap->algo->master_xfer) { |
1045 | #ifdef DEBUG | |
1046 | for (ret = 0; ret < num; ret++) { | |
1047 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
1048 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
1049 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
1050 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
1051 | } |
1052 | #endif | |
1053 | ||
cea443a8 MR |
1054 | if (in_atomic() || irqs_disabled()) { |
1055 | ret = mutex_trylock(&adap->bus_lock); | |
1056 | if (!ret) | |
1057 | /* I2C activity is ongoing. */ | |
1058 | return -EAGAIN; | |
1059 | } else { | |
1060 | mutex_lock_nested(&adap->bus_lock, adap->level); | |
1061 | } | |
1062 | ||
1da177e4 | 1063 | ret = adap->algo->master_xfer(adap,msgs,num); |
5c085d36 | 1064 | mutex_unlock(&adap->bus_lock); |
1da177e4 LT |
1065 | |
1066 | return ret; | |
1067 | } else { | |
1068 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1069 | return -EOPNOTSUPP; |
1da177e4 LT |
1070 | } |
1071 | } | |
c0564606 | 1072 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1073 | |
a1cdedac DB |
1074 | /** |
1075 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1076 | * @client: Handle to slave device | |
1077 | * @buf: Data that will be written to the slave | |
1078 | * @count: How many bytes to write | |
1079 | * | |
1080 | * Returns negative errno, or else the number of bytes written. | |
1081 | */ | |
1da177e4 LT |
1082 | int i2c_master_send(struct i2c_client *client,const char *buf ,int count) |
1083 | { | |
1084 | int ret; | |
1085 | struct i2c_adapter *adap=client->adapter; | |
1086 | struct i2c_msg msg; | |
1087 | ||
815f55f2 JD |
1088 | msg.addr = client->addr; |
1089 | msg.flags = client->flags & I2C_M_TEN; | |
1090 | msg.len = count; | |
1091 | msg.buf = (char *)buf; | |
438d6c2c | 1092 | |
815f55f2 | 1093 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1094 | |
815f55f2 JD |
1095 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes |
1096 | transmitted, else error code. */ | |
1097 | return (ret == 1) ? count : ret; | |
1da177e4 | 1098 | } |
c0564606 | 1099 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1100 | |
a1cdedac DB |
1101 | /** |
1102 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1103 | * @client: Handle to slave device | |
1104 | * @buf: Where to store data read from slave | |
1105 | * @count: How many bytes to read | |
1106 | * | |
1107 | * Returns negative errno, or else the number of bytes read. | |
1108 | */ | |
1da177e4 LT |
1109 | int i2c_master_recv(struct i2c_client *client, char *buf ,int count) |
1110 | { | |
1111 | struct i2c_adapter *adap=client->adapter; | |
1112 | struct i2c_msg msg; | |
1113 | int ret; | |
815f55f2 JD |
1114 | |
1115 | msg.addr = client->addr; | |
1116 | msg.flags = client->flags & I2C_M_TEN; | |
1117 | msg.flags |= I2C_M_RD; | |
1118 | msg.len = count; | |
1119 | msg.buf = buf; | |
1120 | ||
1121 | ret = i2c_transfer(adap, &msg, 1); | |
1122 | ||
1123 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1124 | transmitted, else error code. */ | |
1125 | return (ret == 1) ? count : ret; | |
1da177e4 | 1126 | } |
c0564606 | 1127 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1128 | |
1da177e4 LT |
1129 | /* ---------------------------------------------------- |
1130 | * the i2c address scanning function | |
1131 | * Will not work for 10-bit addresses! | |
1132 | * ---------------------------------------------------- | |
1133 | */ | |
a89ba0bc JD |
1134 | static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind, |
1135 | int (*found_proc) (struct i2c_adapter *, int, int)) | |
1136 | { | |
1137 | int err; | |
1138 | ||
1139 | /* Make sure the address is valid */ | |
1140 | if (addr < 0x03 || addr > 0x77) { | |
1141 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", | |
1142 | addr); | |
1143 | return -EINVAL; | |
9fc6adfa JD |
1144 | } |
1145 | ||
a89ba0bc JD |
1146 | /* Skip if already in use */ |
1147 | if (i2c_check_addr(adapter, addr)) | |
1148 | return 0; | |
1149 | ||
1150 | /* Make sure there is something at this address, unless forced */ | |
4c9337da JD |
1151 | if (kind < 0) { |
1152 | if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1153 | I2C_SMBUS_QUICK, NULL) < 0) | |
1154 | return 0; | |
1155 | ||
1156 | /* prevent 24RF08 corruption */ | |
1157 | if ((addr & ~0x0f) == 0x50) | |
1158 | i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1159 | I2C_SMBUS_QUICK, NULL); | |
1160 | } | |
a89ba0bc JD |
1161 | |
1162 | /* Finally call the custom detection function */ | |
1163 | err = found_proc(adapter, addr, kind); | |
a89ba0bc JD |
1164 | /* -ENODEV can be returned if there is a chip at the given address |
1165 | but it isn't supported by this chip driver. We catch it here as | |
1166 | this isn't an error. */ | |
114fd183 JD |
1167 | if (err == -ENODEV) |
1168 | err = 0; | |
1169 | ||
1170 | if (err) | |
1171 | dev_warn(&adapter->dev, "Client creation failed at 0x%x (%d)\n", | |
1172 | addr, err); | |
1173 | return err; | |
9fc6adfa JD |
1174 | } |
1175 | ||
1da177e4 | 1176 | int i2c_probe(struct i2c_adapter *adapter, |
bfb6df24 | 1177 | const struct i2c_client_address_data *address_data, |
1da177e4 LT |
1178 | int (*found_proc) (struct i2c_adapter *, int, int)) |
1179 | { | |
a89ba0bc | 1180 | int i, err; |
1da177e4 LT |
1181 | int adap_id = i2c_adapter_id(adapter); |
1182 | ||
a89ba0bc JD |
1183 | /* Force entries are done first, and are not affected by ignore |
1184 | entries */ | |
1185 | if (address_data->forces) { | |
bfb6df24 | 1186 | const unsigned short * const *forces = address_data->forces; |
a89ba0bc JD |
1187 | int kind; |
1188 | ||
1189 | for (kind = 0; forces[kind]; kind++) { | |
1190 | for (i = 0; forces[kind][i] != I2C_CLIENT_END; | |
1191 | i += 2) { | |
1192 | if (forces[kind][i] == adap_id | |
1193 | || forces[kind][i] == ANY_I2C_BUS) { | |
1194 | dev_dbg(&adapter->dev, "found force " | |
1195 | "parameter for adapter %d, " | |
1196 | "addr 0x%02x, kind %d\n", | |
1197 | adap_id, forces[kind][i + 1], | |
1198 | kind); | |
1199 | err = i2c_probe_address(adapter, | |
1200 | forces[kind][i + 1], | |
1201 | kind, found_proc); | |
1202 | if (err) | |
1203 | return err; | |
1204 | } | |
1da177e4 LT |
1205 | } |
1206 | } | |
a89ba0bc | 1207 | } |
1da177e4 | 1208 | |
4366dc94 JD |
1209 | /* Stop here if we can't use SMBUS_QUICK */ |
1210 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) { | |
1211 | if (address_data->probe[0] == I2C_CLIENT_END | |
1212 | && address_data->normal_i2c[0] == I2C_CLIENT_END) | |
438d6c2c | 1213 | return 0; |
4366dc94 | 1214 | |
4329cf86 JD |
1215 | dev_dbg(&adapter->dev, "SMBus Quick command not supported, " |
1216 | "can't probe for chips\n"); | |
24a5bb7b | 1217 | return -EOPNOTSUPP; |
4366dc94 JD |
1218 | } |
1219 | ||
a89ba0bc JD |
1220 | /* Probe entries are done second, and are not affected by ignore |
1221 | entries either */ | |
1222 | for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) { | |
1223 | if (address_data->probe[i] == adap_id | |
1224 | || address_data->probe[i] == ANY_I2C_BUS) { | |
1225 | dev_dbg(&adapter->dev, "found probe parameter for " | |
1226 | "adapter %d, addr 0x%02x\n", adap_id, | |
1227 | address_data->probe[i + 1]); | |
1228 | err = i2c_probe_address(adapter, | |
1229 | address_data->probe[i + 1], | |
1230 | -1, found_proc); | |
1231 | if (err) | |
1232 | return err; | |
1da177e4 | 1233 | } |
a89ba0bc | 1234 | } |
1da177e4 | 1235 | |
a89ba0bc JD |
1236 | /* Normal entries are done last, unless shadowed by an ignore entry */ |
1237 | for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) { | |
1238 | int j, ignore; | |
1239 | ||
1240 | ignore = 0; | |
1241 | for (j = 0; address_data->ignore[j] != I2C_CLIENT_END; | |
1242 | j += 2) { | |
1243 | if ((address_data->ignore[j] == adap_id || | |
1244 | address_data->ignore[j] == ANY_I2C_BUS) | |
1245 | && address_data->ignore[j + 1] | |
1246 | == address_data->normal_i2c[i]) { | |
1247 | dev_dbg(&adapter->dev, "found ignore " | |
1248 | "parameter for adapter %d, " | |
1249 | "addr 0x%02x\n", adap_id, | |
1250 | address_data->ignore[j + 1]); | |
2369df93 MH |
1251 | ignore = 1; |
1252 | break; | |
1da177e4 LT |
1253 | } |
1254 | } | |
a89ba0bc | 1255 | if (ignore) |
1da177e4 LT |
1256 | continue; |
1257 | ||
a89ba0bc JD |
1258 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
1259 | "addr 0x%02x\n", adap_id, | |
1260 | address_data->normal_i2c[i]); | |
1261 | err = i2c_probe_address(adapter, address_data->normal_i2c[i], | |
1262 | -1, found_proc); | |
1263 | if (err) | |
1264 | return err; | |
1da177e4 | 1265 | } |
a89ba0bc | 1266 | |
1da177e4 LT |
1267 | return 0; |
1268 | } | |
c0564606 | 1269 | EXPORT_SYMBOL(i2c_probe); |
1da177e4 | 1270 | |
4735c98f JD |
1271 | /* Separate detection function for new-style drivers */ |
1272 | static int i2c_detect_address(struct i2c_client *temp_client, int kind, | |
1273 | struct i2c_driver *driver) | |
1274 | { | |
1275 | struct i2c_board_info info; | |
1276 | struct i2c_adapter *adapter = temp_client->adapter; | |
1277 | int addr = temp_client->addr; | |
1278 | int err; | |
1279 | ||
1280 | /* Make sure the address is valid */ | |
1281 | if (addr < 0x03 || addr > 0x77) { | |
1282 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", | |
1283 | addr); | |
1284 | return -EINVAL; | |
1285 | } | |
1286 | ||
1287 | /* Skip if already in use */ | |
1288 | if (i2c_check_addr(adapter, addr)) | |
1289 | return 0; | |
1290 | ||
1291 | /* Make sure there is something at this address, unless forced */ | |
1292 | if (kind < 0) { | |
1293 | if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1294 | I2C_SMBUS_QUICK, NULL) < 0) | |
1295 | return 0; | |
1296 | ||
1297 | /* prevent 24RF08 corruption */ | |
1298 | if ((addr & ~0x0f) == 0x50) | |
1299 | i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1300 | I2C_SMBUS_QUICK, NULL); | |
1301 | } | |
1302 | ||
1303 | /* Finally call the custom detection function */ | |
1304 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
1305 | info.addr = addr; | |
1306 | err = driver->detect(temp_client, kind, &info); | |
1307 | if (err) { | |
1308 | /* -ENODEV is returned if the detection fails. We catch it | |
1309 | here as this isn't an error. */ | |
1310 | return err == -ENODEV ? 0 : err; | |
1311 | } | |
1312 | ||
1313 | /* Consistency check */ | |
1314 | if (info.type[0] == '\0') { | |
1315 | dev_err(&adapter->dev, "%s detection function provided " | |
1316 | "no name for 0x%x\n", driver->driver.name, | |
1317 | addr); | |
1318 | } else { | |
1319 | struct i2c_client *client; | |
1320 | ||
1321 | /* Detection succeeded, instantiate the device */ | |
1322 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", | |
1323 | info.type, info.addr); | |
1324 | client = i2c_new_device(adapter, &info); | |
1325 | if (client) | |
1326 | list_add_tail(&client->detected, &driver->clients); | |
1327 | else | |
1328 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
1329 | info.type, info.addr); | |
1330 | } | |
1331 | return 0; | |
1332 | } | |
1333 | ||
1334 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
1335 | { | |
1336 | const struct i2c_client_address_data *address_data; | |
1337 | struct i2c_client *temp_client; | |
1338 | int i, err = 0; | |
1339 | int adap_id = i2c_adapter_id(adapter); | |
1340 | ||
1341 | address_data = driver->address_data; | |
1342 | if (!driver->detect || !address_data) | |
1343 | return 0; | |
1344 | ||
1345 | /* Set up a temporary client to help detect callback */ | |
1346 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
1347 | if (!temp_client) | |
1348 | return -ENOMEM; | |
1349 | temp_client->adapter = adapter; | |
1350 | ||
1351 | /* Force entries are done first, and are not affected by ignore | |
1352 | entries */ | |
1353 | if (address_data->forces) { | |
1354 | const unsigned short * const *forces = address_data->forces; | |
1355 | int kind; | |
1356 | ||
1357 | for (kind = 0; forces[kind]; kind++) { | |
1358 | for (i = 0; forces[kind][i] != I2C_CLIENT_END; | |
1359 | i += 2) { | |
1360 | if (forces[kind][i] == adap_id | |
1361 | || forces[kind][i] == ANY_I2C_BUS) { | |
1362 | dev_dbg(&adapter->dev, "found force " | |
1363 | "parameter for adapter %d, " | |
1364 | "addr 0x%02x, kind %d\n", | |
1365 | adap_id, forces[kind][i + 1], | |
1366 | kind); | |
1367 | temp_client->addr = forces[kind][i + 1]; | |
1368 | err = i2c_detect_address(temp_client, | |
1369 | kind, driver); | |
1370 | if (err) | |
1371 | goto exit_free; | |
1372 | } | |
1373 | } | |
1374 | } | |
1375 | } | |
1376 | ||
4329cf86 JD |
1377 | /* Stop here if the classes do not match */ |
1378 | if (!(adapter->class & driver->class)) | |
1379 | goto exit_free; | |
1380 | ||
4735c98f JD |
1381 | /* Stop here if we can't use SMBUS_QUICK */ |
1382 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) { | |
1383 | if (address_data->probe[0] == I2C_CLIENT_END | |
1384 | && address_data->normal_i2c[0] == I2C_CLIENT_END) | |
1385 | goto exit_free; | |
1386 | ||
1387 | dev_warn(&adapter->dev, "SMBus Quick command not supported, " | |
1388 | "can't probe for chips\n"); | |
1389 | err = -EOPNOTSUPP; | |
1390 | goto exit_free; | |
1391 | } | |
1392 | ||
4735c98f JD |
1393 | /* Probe entries are done second, and are not affected by ignore |
1394 | entries either */ | |
1395 | for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) { | |
1396 | if (address_data->probe[i] == adap_id | |
1397 | || address_data->probe[i] == ANY_I2C_BUS) { | |
1398 | dev_dbg(&adapter->dev, "found probe parameter for " | |
1399 | "adapter %d, addr 0x%02x\n", adap_id, | |
1400 | address_data->probe[i + 1]); | |
1401 | temp_client->addr = address_data->probe[i + 1]; | |
1402 | err = i2c_detect_address(temp_client, -1, driver); | |
1403 | if (err) | |
1404 | goto exit_free; | |
1405 | } | |
1406 | } | |
1407 | ||
1408 | /* Normal entries are done last, unless shadowed by an ignore entry */ | |
1409 | for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) { | |
1410 | int j, ignore; | |
1411 | ||
1412 | ignore = 0; | |
1413 | for (j = 0; address_data->ignore[j] != I2C_CLIENT_END; | |
1414 | j += 2) { | |
1415 | if ((address_data->ignore[j] == adap_id || | |
1416 | address_data->ignore[j] == ANY_I2C_BUS) | |
1417 | && address_data->ignore[j + 1] | |
1418 | == address_data->normal_i2c[i]) { | |
1419 | dev_dbg(&adapter->dev, "found ignore " | |
1420 | "parameter for adapter %d, " | |
1421 | "addr 0x%02x\n", adap_id, | |
1422 | address_data->ignore[j + 1]); | |
1423 | ignore = 1; | |
1424 | break; | |
1425 | } | |
1426 | } | |
1427 | if (ignore) | |
1428 | continue; | |
1429 | ||
1430 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " | |
1431 | "addr 0x%02x\n", adap_id, | |
1432 | address_data->normal_i2c[i]); | |
1433 | temp_client->addr = address_data->normal_i2c[i]; | |
1434 | err = i2c_detect_address(temp_client, -1, driver); | |
1435 | if (err) | |
1436 | goto exit_free; | |
1437 | } | |
1438 | ||
1439 | exit_free: | |
1440 | kfree(temp_client); | |
1441 | return err; | |
1442 | } | |
1443 | ||
12b5053a JD |
1444 | struct i2c_client * |
1445 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1446 | struct i2c_board_info *info, | |
1447 | unsigned short const *addr_list) | |
1448 | { | |
1449 | int i; | |
1450 | ||
1451 | /* Stop here if the bus doesn't support probing */ | |
1452 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { | |
1453 | dev_err(&adap->dev, "Probing not supported\n"); | |
1454 | return NULL; | |
1455 | } | |
1456 | ||
12b5053a JD |
1457 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1458 | /* Check address validity */ | |
1459 | if (addr_list[i] < 0x03 || addr_list[i] > 0x77) { | |
1460 | dev_warn(&adap->dev, "Invalid 7-bit address " | |
1461 | "0x%02x\n", addr_list[i]); | |
1462 | continue; | |
1463 | } | |
1464 | ||
1465 | /* Check address availability */ | |
9b766b81 | 1466 | if (i2c_check_addr(adap, addr_list[i])) { |
12b5053a JD |
1467 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1468 | "use, not probing\n", addr_list[i]); | |
1469 | continue; | |
1470 | } | |
1471 | ||
1472 | /* Test address responsiveness | |
1473 | The default probe method is a quick write, but it is known | |
1474 | to corrupt the 24RF08 EEPROMs due to a state machine bug, | |
1475 | and could also irreversibly write-protect some EEPROMs, so | |
1476 | for address ranges 0x30-0x37 and 0x50-0x5f, we use a byte | |
1477 | read instead. Also, some bus drivers don't implement | |
1478 | quick write, so we fallback to a byte read it that case | |
1479 | too. */ | |
1480 | if ((addr_list[i] & ~0x07) == 0x30 | |
1481 | || (addr_list[i] & ~0x0f) == 0x50 | |
1482 | || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) { | |
b25b791b HV |
1483 | union i2c_smbus_data data; |
1484 | ||
12b5053a JD |
1485 | if (i2c_smbus_xfer(adap, addr_list[i], 0, |
1486 | I2C_SMBUS_READ, 0, | |
b25b791b | 1487 | I2C_SMBUS_BYTE, &data) >= 0) |
12b5053a JD |
1488 | break; |
1489 | } else { | |
1490 | if (i2c_smbus_xfer(adap, addr_list[i], 0, | |
1491 | I2C_SMBUS_WRITE, 0, | |
1492 | I2C_SMBUS_QUICK, NULL) >= 0) | |
1493 | break; | |
1494 | } | |
1495 | } | |
12b5053a JD |
1496 | |
1497 | if (addr_list[i] == I2C_CLIENT_END) { | |
1498 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1499 | return NULL; | |
1500 | } | |
1501 | ||
1502 | info->addr = addr_list[i]; | |
1503 | return i2c_new_device(adap, info); | |
1504 | } | |
1505 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
1506 | ||
1da177e4 LT |
1507 | struct i2c_adapter* i2c_get_adapter(int id) |
1508 | { | |
1da177e4 | 1509 | struct i2c_adapter *adapter; |
438d6c2c | 1510 | |
caada32a | 1511 | mutex_lock(&core_lock); |
1cf92b45 | 1512 | adapter = idr_find(&i2c_adapter_idr, id); |
a0920e10 MH |
1513 | if (adapter && !try_module_get(adapter->owner)) |
1514 | adapter = NULL; | |
1515 | ||
caada32a | 1516 | mutex_unlock(&core_lock); |
a0920e10 | 1517 | return adapter; |
1da177e4 | 1518 | } |
c0564606 | 1519 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
1520 | |
1521 | void i2c_put_adapter(struct i2c_adapter *adap) | |
1522 | { | |
1523 | module_put(adap->owner); | |
1524 | } | |
c0564606 | 1525 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
1526 | |
1527 | /* The SMBus parts */ | |
1528 | ||
438d6c2c | 1529 | #define POLY (0x1070U << 3) |
09b8ce0a | 1530 | static u8 crc8(u16 data) |
1da177e4 LT |
1531 | { |
1532 | int i; | |
438d6c2c | 1533 | |
1da177e4 | 1534 | for(i = 0; i < 8; i++) { |
438d6c2c | 1535 | if (data & 0x8000) |
1da177e4 LT |
1536 | data = data ^ POLY; |
1537 | data = data << 1; | |
1538 | } | |
1539 | return (u8)(data >> 8); | |
1540 | } | |
1541 | ||
421ef47b JD |
1542 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
1543 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
1544 | { |
1545 | int i; | |
1546 | ||
1547 | for(i = 0; i < count; i++) | |
421ef47b | 1548 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
1549 | return crc; |
1550 | } | |
1551 | ||
421ef47b JD |
1552 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
1553 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 1554 | { |
421ef47b JD |
1555 | /* The address will be sent first */ |
1556 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
1557 | pec = i2c_smbus_pec(pec, &addr, 1); | |
1558 | ||
1559 | /* The data buffer follows */ | |
1560 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
1561 | } |
1562 | ||
421ef47b JD |
1563 | /* Used for write only transactions */ |
1564 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 1565 | { |
421ef47b JD |
1566 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
1567 | msg->len++; | |
1da177e4 LT |
1568 | } |
1569 | ||
421ef47b JD |
1570 | /* Return <0 on CRC error |
1571 | If there was a write before this read (most cases) we need to take the | |
1572 | partial CRC from the write part into account. | |
1573 | Note that this function does modify the message (we need to decrease the | |
1574 | message length to hide the CRC byte from the caller). */ | |
1575 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 1576 | { |
421ef47b JD |
1577 | u8 rpec = msg->buf[--msg->len]; |
1578 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 1579 | |
1da177e4 LT |
1580 | if (rpec != cpec) { |
1581 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
1582 | rpec, cpec); | |
24a5bb7b | 1583 | return -EBADMSG; |
1da177e4 | 1584 | } |
438d6c2c | 1585 | return 0; |
1da177e4 LT |
1586 | } |
1587 | ||
a1cdedac DB |
1588 | /** |
1589 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
1590 | * @client: Handle to slave device | |
1591 | * | |
1592 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
1593 | * else the byte received from the device. | |
1594 | */ | |
1da177e4 LT |
1595 | s32 i2c_smbus_read_byte(struct i2c_client *client) |
1596 | { | |
1597 | union i2c_smbus_data data; | |
24a5bb7b DB |
1598 | int status; |
1599 | ||
1600 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1601 | I2C_SMBUS_READ, 0, | |
1602 | I2C_SMBUS_BYTE, &data); | |
1603 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1604 | } |
c0564606 | 1605 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 1606 | |
a1cdedac DB |
1607 | /** |
1608 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
1609 | * @client: Handle to slave device | |
1610 | * @value: Byte to be sent | |
1611 | * | |
1612 | * This executes the SMBus "send byte" protocol, returning negative errno | |
1613 | * else zero on success. | |
1614 | */ | |
1da177e4 LT |
1615 | s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) |
1616 | { | |
1da177e4 | 1617 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
421ef47b | 1618 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 1619 | } |
c0564606 | 1620 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 1621 | |
a1cdedac DB |
1622 | /** |
1623 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
1624 | * @client: Handle to slave device | |
1625 | * @command: Byte interpreted by slave | |
1626 | * | |
1627 | * This executes the SMBus "read byte" protocol, returning negative errno | |
1628 | * else a data byte received from the device. | |
1629 | */ | |
1da177e4 LT |
1630 | s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) |
1631 | { | |
1632 | union i2c_smbus_data data; | |
24a5bb7b DB |
1633 | int status; |
1634 | ||
1635 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1636 | I2C_SMBUS_READ, command, | |
1637 | I2C_SMBUS_BYTE_DATA, &data); | |
1638 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1639 | } |
c0564606 | 1640 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 1641 | |
a1cdedac DB |
1642 | /** |
1643 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
1644 | * @client: Handle to slave device | |
1645 | * @command: Byte interpreted by slave | |
1646 | * @value: Byte being written | |
1647 | * | |
1648 | * This executes the SMBus "write byte" protocol, returning negative errno | |
1649 | * else zero on success. | |
1650 | */ | |
1da177e4 LT |
1651 | s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) |
1652 | { | |
1653 | union i2c_smbus_data data; | |
1654 | data.byte = value; | |
1655 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1656 | I2C_SMBUS_WRITE,command, | |
1657 | I2C_SMBUS_BYTE_DATA,&data); | |
1658 | } | |
c0564606 | 1659 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 1660 | |
a1cdedac DB |
1661 | /** |
1662 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
1663 | * @client: Handle to slave device | |
1664 | * @command: Byte interpreted by slave | |
1665 | * | |
1666 | * This executes the SMBus "read word" protocol, returning negative errno | |
1667 | * else a 16-bit unsigned "word" received from the device. | |
1668 | */ | |
1da177e4 LT |
1669 | s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) |
1670 | { | |
1671 | union i2c_smbus_data data; | |
24a5bb7b DB |
1672 | int status; |
1673 | ||
1674 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1675 | I2C_SMBUS_READ, command, | |
1676 | I2C_SMBUS_WORD_DATA, &data); | |
1677 | return (status < 0) ? status : data.word; | |
1da177e4 | 1678 | } |
c0564606 | 1679 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 1680 | |
a1cdedac DB |
1681 | /** |
1682 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
1683 | * @client: Handle to slave device | |
1684 | * @command: Byte interpreted by slave | |
1685 | * @value: 16-bit "word" being written | |
1686 | * | |
1687 | * This executes the SMBus "write word" protocol, returning negative errno | |
1688 | * else zero on success. | |
1689 | */ | |
1da177e4 LT |
1690 | s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) |
1691 | { | |
1692 | union i2c_smbus_data data; | |
1693 | data.word = value; | |
1694 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1695 | I2C_SMBUS_WRITE,command, | |
1696 | I2C_SMBUS_WORD_DATA,&data); | |
1697 | } | |
c0564606 | 1698 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 1699 | |
596c88f4 PM |
1700 | /** |
1701 | * i2c_smbus_process_call - SMBus "process call" protocol | |
1702 | * @client: Handle to slave device | |
1703 | * @command: Byte interpreted by slave | |
1704 | * @value: 16-bit "word" being written | |
1705 | * | |
1706 | * This executes the SMBus "process call" protocol, returning negative errno | |
1707 | * else a 16-bit unsigned "word" received from the device. | |
1708 | */ | |
1709 | s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value) | |
1710 | { | |
1711 | union i2c_smbus_data data; | |
1712 | int status; | |
1713 | data.word = value; | |
1714 | ||
1715 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1716 | I2C_SMBUS_WRITE, command, | |
1717 | I2C_SMBUS_PROC_CALL, &data); | |
1718 | return (status < 0) ? status : data.word; | |
1719 | } | |
1720 | EXPORT_SYMBOL(i2c_smbus_process_call); | |
1721 | ||
a64ec07d | 1722 | /** |
a1cdedac | 1723 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 1724 | * @client: Handle to slave device |
a1cdedac | 1725 | * @command: Byte interpreted by slave |
a64ec07d DB |
1726 | * @values: Byte array into which data will be read; big enough to hold |
1727 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
1728 | * | |
a1cdedac DB |
1729 | * This executes the SMBus "block read" protocol, returning negative errno |
1730 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
1731 | * |
1732 | * Note that using this function requires that the client's adapter support | |
1733 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
1734 | * support this; its emulation through I2C messaging relies on a specific | |
1735 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
1736 | */ | |
b86a1bc8 JD |
1737 | s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, |
1738 | u8 *values) | |
1739 | { | |
1740 | union i2c_smbus_data data; | |
24a5bb7b | 1741 | int status; |
b86a1bc8 | 1742 | |
24a5bb7b DB |
1743 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1744 | I2C_SMBUS_READ, command, | |
1745 | I2C_SMBUS_BLOCK_DATA, &data); | |
1746 | if (status) | |
1747 | return status; | |
b86a1bc8 JD |
1748 | |
1749 | memcpy(values, &data.block[1], data.block[0]); | |
1750 | return data.block[0]; | |
1751 | } | |
1752 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
1753 | ||
a1cdedac DB |
1754 | /** |
1755 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
1756 | * @client: Handle to slave device | |
1757 | * @command: Byte interpreted by slave | |
1758 | * @length: Size of data block; SMBus allows at most 32 bytes | |
1759 | * @values: Byte array which will be written. | |
1760 | * | |
1761 | * This executes the SMBus "block write" protocol, returning negative errno | |
1762 | * else zero on success. | |
1763 | */ | |
1da177e4 | 1764 | s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1765 | u8 length, const u8 *values) |
1da177e4 LT |
1766 | { |
1767 | union i2c_smbus_data data; | |
7656032b | 1768 | |
1da177e4 LT |
1769 | if (length > I2C_SMBUS_BLOCK_MAX) |
1770 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 1771 | data.block[0] = length; |
7656032b | 1772 | memcpy(&data.block[1], values, length); |
1da177e4 LT |
1773 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
1774 | I2C_SMBUS_WRITE,command, | |
1775 | I2C_SMBUS_BLOCK_DATA,&data); | |
1776 | } | |
c0564606 | 1777 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
1778 | |
1779 | /* Returns the number of read bytes */ | |
4b2643d7 JD |
1780 | s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, |
1781 | u8 length, u8 *values) | |
1da177e4 LT |
1782 | { |
1783 | union i2c_smbus_data data; | |
24a5bb7b | 1784 | int status; |
7656032b | 1785 | |
4b2643d7 JD |
1786 | if (length > I2C_SMBUS_BLOCK_MAX) |
1787 | length = I2C_SMBUS_BLOCK_MAX; | |
1788 | data.block[0] = length; | |
24a5bb7b DB |
1789 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1790 | I2C_SMBUS_READ, command, | |
1791 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1792 | if (status < 0) | |
1793 | return status; | |
7656032b JD |
1794 | |
1795 | memcpy(values, &data.block[1], data.block[0]); | |
1796 | return data.block[0]; | |
1da177e4 | 1797 | } |
c0564606 | 1798 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 1799 | |
21bbd691 | 1800 | s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1801 | u8 length, const u8 *values) |
21bbd691 JD |
1802 | { |
1803 | union i2c_smbus_data data; | |
1804 | ||
1805 | if (length > I2C_SMBUS_BLOCK_MAX) | |
1806 | length = I2C_SMBUS_BLOCK_MAX; | |
1807 | data.block[0] = length; | |
1808 | memcpy(data.block + 1, values, length); | |
1809 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1810 | I2C_SMBUS_WRITE, command, | |
1811 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1812 | } | |
c0564606 | 1813 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 1814 | |
438d6c2c | 1815 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 1816 | No checking of parameters is done! */ |
438d6c2c | 1817 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, |
1da177e4 | 1818 | unsigned short flags, |
438d6c2c | 1819 | char read_write, u8 command, int size, |
1da177e4 LT |
1820 | union i2c_smbus_data * data) |
1821 | { | |
1822 | /* So we need to generate a series of msgs. In the case of writing, we | |
1823 | need to use only one message; when reading, we need two. We initialize | |
1824 | most things with sane defaults, to keep the code below somewhat | |
1825 | simpler. */ | |
5c50d188 HI |
1826 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
1827 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
1da177e4 | 1828 | int num = read_write == I2C_SMBUS_READ?2:1; |
438d6c2c | 1829 | struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 }, |
1da177e4 LT |
1830 | { addr, flags | I2C_M_RD, 0, msgbuf1 } |
1831 | }; | |
1832 | int i; | |
421ef47b | 1833 | u8 partial_pec = 0; |
24a5bb7b | 1834 | int status; |
1da177e4 LT |
1835 | |
1836 | msgbuf0[0] = command; | |
1837 | switch(size) { | |
1838 | case I2C_SMBUS_QUICK: | |
1839 | msg[0].len = 0; | |
1840 | /* Special case: The read/write field is used as data */ | |
f29d2e02 RK |
1841 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
1842 | I2C_M_RD : 0); | |
1da177e4 LT |
1843 | num = 1; |
1844 | break; | |
1845 | case I2C_SMBUS_BYTE: | |
1846 | if (read_write == I2C_SMBUS_READ) { | |
1847 | /* Special case: only a read! */ | |
1848 | msg[0].flags = I2C_M_RD | flags; | |
1849 | num = 1; | |
1850 | } | |
1851 | break; | |
1852 | case I2C_SMBUS_BYTE_DATA: | |
1853 | if (read_write == I2C_SMBUS_READ) | |
1854 | msg[1].len = 1; | |
1855 | else { | |
1856 | msg[0].len = 2; | |
1857 | msgbuf0[1] = data->byte; | |
1858 | } | |
1859 | break; | |
1860 | case I2C_SMBUS_WORD_DATA: | |
1861 | if (read_write == I2C_SMBUS_READ) | |
1862 | msg[1].len = 2; | |
1863 | else { | |
1864 | msg[0].len=3; | |
1865 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1866 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1867 | } |
1868 | break; | |
1869 | case I2C_SMBUS_PROC_CALL: | |
1870 | num = 2; /* Special case */ | |
1871 | read_write = I2C_SMBUS_READ; | |
1872 | msg[0].len = 3; | |
1873 | msg[1].len = 2; | |
1874 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1875 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1876 | break; |
1877 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 1878 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
1879 | msg[1].flags |= I2C_M_RECV_LEN; |
1880 | msg[1].len = 1; /* block length will be added by | |
1881 | the underlying bus driver */ | |
1da177e4 LT |
1882 | } else { |
1883 | msg[0].len = data->block[0] + 2; | |
1884 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
1885 | dev_err(&adapter->dev, |
1886 | "Invalid block write size %d\n", | |
1887 | data->block[0]); | |
1888 | return -EINVAL; | |
1da177e4 | 1889 | } |
5c50d188 | 1890 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
1891 | msgbuf0[i] = data->block[i-1]; |
1892 | } | |
1893 | break; | |
1894 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
1895 | num = 2; /* Another special case */ |
1896 | read_write = I2C_SMBUS_READ; | |
1897 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
1898 | dev_err(&adapter->dev, |
1899 | "Invalid block write size %d\n", | |
209d27c3 | 1900 | data->block[0]); |
24a5bb7b | 1901 | return -EINVAL; |
209d27c3 JD |
1902 | } |
1903 | msg[0].len = data->block[0] + 2; | |
1904 | for (i = 1; i < msg[0].len; i++) | |
1905 | msgbuf0[i] = data->block[i-1]; | |
1906 | msg[1].flags |= I2C_M_RECV_LEN; | |
1907 | msg[1].len = 1; /* block length will be added by | |
1908 | the underlying bus driver */ | |
1909 | break; | |
1da177e4 LT |
1910 | case I2C_SMBUS_I2C_BLOCK_DATA: |
1911 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 1912 | msg[1].len = data->block[0]; |
1da177e4 LT |
1913 | } else { |
1914 | msg[0].len = data->block[0] + 1; | |
30dac746 | 1915 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
1916 | dev_err(&adapter->dev, |
1917 | "Invalid block write size %d\n", | |
1918 | data->block[0]); | |
1919 | return -EINVAL; | |
1da177e4 LT |
1920 | } |
1921 | for (i = 1; i <= data->block[0]; i++) | |
1922 | msgbuf0[i] = data->block[i]; | |
1923 | } | |
1924 | break; | |
1925 | default: | |
24a5bb7b DB |
1926 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
1927 | return -EOPNOTSUPP; | |
1da177e4 LT |
1928 | } |
1929 | ||
421ef47b JD |
1930 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
1931 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
1932 | if (i) { | |
1933 | /* Compute PEC if first message is a write */ | |
1934 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 1935 | if (num == 1) /* Write only */ |
421ef47b JD |
1936 | i2c_smbus_add_pec(&msg[0]); |
1937 | else /* Write followed by read */ | |
1938 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
1939 | } | |
1940 | /* Ask for PEC if last message is a read */ | |
1941 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 1942 | msg[num-1].len++; |
421ef47b JD |
1943 | } |
1944 | ||
24a5bb7b DB |
1945 | status = i2c_transfer(adapter, msg, num); |
1946 | if (status < 0) | |
1947 | return status; | |
1da177e4 | 1948 | |
421ef47b JD |
1949 | /* Check PEC if last message is a read */ |
1950 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
1951 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
1952 | if (status < 0) | |
1953 | return status; | |
421ef47b JD |
1954 | } |
1955 | ||
1da177e4 LT |
1956 | if (read_write == I2C_SMBUS_READ) |
1957 | switch(size) { | |
1958 | case I2C_SMBUS_BYTE: | |
1959 | data->byte = msgbuf0[0]; | |
1960 | break; | |
1961 | case I2C_SMBUS_BYTE_DATA: | |
1962 | data->byte = msgbuf1[0]; | |
1963 | break; | |
438d6c2c | 1964 | case I2C_SMBUS_WORD_DATA: |
1da177e4 LT |
1965 | case I2C_SMBUS_PROC_CALL: |
1966 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
1967 | break; | |
1968 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
4b2643d7 | 1969 | for (i = 0; i < data->block[0]; i++) |
1da177e4 LT |
1970 | data->block[i+1] = msgbuf1[i]; |
1971 | break; | |
209d27c3 JD |
1972 | case I2C_SMBUS_BLOCK_DATA: |
1973 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
1974 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
1975 | data->block[i] = msgbuf1[i]; | |
1976 | break; | |
1da177e4 LT |
1977 | } |
1978 | return 0; | |
1979 | } | |
1980 | ||
a1cdedac DB |
1981 | /** |
1982 | * i2c_smbus_xfer - execute SMBus protocol operations | |
1983 | * @adapter: Handle to I2C bus | |
1984 | * @addr: Address of SMBus slave on that bus | |
1985 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
1986 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
1987 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
1988 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
1989 | * @data: Data to be read or written | |
1990 | * | |
1991 | * This executes an SMBus protocol operation, and returns a negative | |
1992 | * errno code else zero on success. | |
1993 | */ | |
09b8ce0a | 1994 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
a1cdedac | 1995 | char read_write, u8 command, int protocol, |
09b8ce0a | 1996 | union i2c_smbus_data *data) |
1da177e4 LT |
1997 | { |
1998 | s32 res; | |
1da177e4 LT |
1999 | |
2000 | flags &= I2C_M_TEN | I2C_CLIENT_PEC; | |
1da177e4 LT |
2001 | |
2002 | if (adapter->algo->smbus_xfer) { | |
5c085d36 | 2003 | mutex_lock(&adapter->bus_lock); |
1da177e4 | 2004 | res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write, |
a1cdedac | 2005 | command, protocol, data); |
5c085d36 | 2006 | mutex_unlock(&adapter->bus_lock); |
1da177e4 LT |
2007 | } else |
2008 | res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write, | |
a1cdedac | 2009 | command, protocol, data); |
1da177e4 | 2010 | |
1da177e4 LT |
2011 | return res; |
2012 | } | |
1da177e4 | 2013 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
2014 | |
2015 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
2016 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
2017 | MODULE_LICENSE("GPL"); |