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