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Commit | Line | Data |
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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> | |
b3585e4f | 32 | #include <linux/mutex.h> |
b8d6f45b | 33 | #include <linux/completion.h> |
cea443a8 MR |
34 | #include <linux/hardirq.h> |
35 | #include <linux/irqflags.h> | |
f18c41da | 36 | #include <linux/rwsem.h> |
6de468ae | 37 | #include <linux/pm_runtime.h> |
1da177e4 LT |
38 | #include <asm/uaccess.h> |
39 | ||
9c1600ed DB |
40 | #include "i2c-core.h" |
41 | ||
1da177e4 | 42 | |
6629dcff | 43 | /* core_lock protects i2c_adapter_idr, and guarantees |
35fc37f8 JD |
44 | that device detection, deletion of detected devices, and attach_adapter |
45 | and detach_adapter calls are serialized */ | |
caada32a | 46 | static DEFINE_MUTEX(core_lock); |
1da177e4 LT |
47 | static DEFINE_IDR(i2c_adapter_idr); |
48 | ||
4f8cf824 | 49 | static struct device_type i2c_client_type; |
f8a227e8 | 50 | static int i2c_check_addr(struct i2c_adapter *adapter, int addr); |
4735c98f | 51 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
f37dd80a DB |
52 | |
53 | /* ------------------------------------------------------------------------- */ | |
54 | ||
d2653e92 JD |
55 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
56 | const struct i2c_client *client) | |
57 | { | |
58 | while (id->name[0]) { | |
59 | if (strcmp(client->name, id->name) == 0) | |
60 | return id; | |
61 | id++; | |
62 | } | |
63 | return NULL; | |
64 | } | |
65 | ||
1da177e4 LT |
66 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
67 | { | |
51298d12 JD |
68 | struct i2c_client *client = i2c_verify_client(dev); |
69 | struct i2c_driver *driver; | |
70 | ||
71 | if (!client) | |
72 | return 0; | |
7b4fbc50 | 73 | |
51298d12 | 74 | driver = to_i2c_driver(drv); |
d2653e92 JD |
75 | /* match on an id table if there is one */ |
76 | if (driver->id_table) | |
77 | return i2c_match_id(driver->id_table, client) != NULL; | |
78 | ||
eb8a7908 | 79 | return 0; |
1da177e4 LT |
80 | } |
81 | ||
7b4fbc50 DB |
82 | #ifdef CONFIG_HOTPLUG |
83 | ||
84 | /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ | |
7eff2e7a | 85 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 DB |
86 | { |
87 | struct i2c_client *client = to_i2c_client(dev); | |
7b4fbc50 | 88 | |
eb8a7908 JD |
89 | if (add_uevent_var(env, "MODALIAS=%s%s", |
90 | I2C_MODULE_PREFIX, client->name)) | |
91 | return -ENOMEM; | |
7b4fbc50 DB |
92 | dev_dbg(dev, "uevent\n"); |
93 | return 0; | |
94 | } | |
95 | ||
96 | #else | |
97 | #define i2c_device_uevent NULL | |
98 | #endif /* CONFIG_HOTPLUG */ | |
99 | ||
f37dd80a | 100 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 101 | { |
51298d12 JD |
102 | struct i2c_client *client = i2c_verify_client(dev); |
103 | struct i2c_driver *driver; | |
50c3304a | 104 | int status; |
7b4fbc50 | 105 | |
51298d12 JD |
106 | if (!client) |
107 | return 0; | |
108 | ||
109 | driver = to_i2c_driver(dev->driver); | |
e0457442 | 110 | if (!driver->probe || !driver->id_table) |
7b4fbc50 DB |
111 | return -ENODEV; |
112 | client->driver = driver; | |
ee35425c MP |
113 | if (!device_can_wakeup(&client->dev)) |
114 | device_init_wakeup(&client->dev, | |
115 | client->flags & I2C_CLIENT_WAKE); | |
7b4fbc50 | 116 | dev_dbg(dev, "probe\n"); |
d2653e92 | 117 | |
e0457442 | 118 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
e4a7b9b0 | 119 | if (status) { |
50c3304a | 120 | client->driver = NULL; |
e4a7b9b0 WS |
121 | i2c_set_clientdata(client, NULL); |
122 | } | |
50c3304a | 123 | return status; |
f37dd80a | 124 | } |
1da177e4 | 125 | |
f37dd80a DB |
126 | static int i2c_device_remove(struct device *dev) |
127 | { | |
51298d12 | 128 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 DB |
129 | struct i2c_driver *driver; |
130 | int status; | |
131 | ||
51298d12 | 132 | if (!client || !dev->driver) |
a1d9e6e4 DB |
133 | return 0; |
134 | ||
135 | driver = to_i2c_driver(dev->driver); | |
136 | if (driver->remove) { | |
137 | dev_dbg(dev, "remove\n"); | |
138 | status = driver->remove(client); | |
139 | } else { | |
140 | dev->driver = NULL; | |
141 | status = 0; | |
142 | } | |
e4a7b9b0 | 143 | if (status == 0) { |
a1d9e6e4 | 144 | client->driver = NULL; |
e4a7b9b0 WS |
145 | i2c_set_clientdata(client, NULL); |
146 | } | |
a1d9e6e4 | 147 | return status; |
1da177e4 LT |
148 | } |
149 | ||
f37dd80a | 150 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 151 | { |
51298d12 | 152 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
153 | struct i2c_driver *driver; |
154 | ||
51298d12 | 155 | if (!client || !dev->driver) |
f37dd80a DB |
156 | return; |
157 | driver = to_i2c_driver(dev->driver); | |
158 | if (driver->shutdown) | |
51298d12 | 159 | driver->shutdown(client); |
1da177e4 LT |
160 | } |
161 | ||
2f60ba70 RW |
162 | #ifdef CONFIG_PM_SLEEP |
163 | static int i2c_legacy_suspend(struct device *dev, pm_message_t mesg) | |
54067ee2 | 164 | { |
2f60ba70 RW |
165 | struct i2c_client *client = i2c_verify_client(dev); |
166 | struct i2c_driver *driver; | |
54067ee2 | 167 | |
2f60ba70 | 168 | if (!client || !dev->driver) |
54067ee2 | 169 | return 0; |
2f60ba70 RW |
170 | driver = to_i2c_driver(dev->driver); |
171 | if (!driver->suspend) | |
54067ee2 | 172 | return 0; |
2f60ba70 | 173 | return driver->suspend(client, mesg); |
54067ee2 | 174 | } |
175 | ||
2f60ba70 | 176 | static int i2c_legacy_resume(struct device *dev) |
54067ee2 | 177 | { |
2f60ba70 RW |
178 | struct i2c_client *client = i2c_verify_client(dev); |
179 | struct i2c_driver *driver; | |
54067ee2 | 180 | |
2f60ba70 | 181 | if (!client || !dev->driver) |
54067ee2 | 182 | return 0; |
2f60ba70 RW |
183 | driver = to_i2c_driver(dev->driver); |
184 | if (!driver->resume) | |
54067ee2 | 185 | return 0; |
2f60ba70 | 186 | return driver->resume(client); |
54067ee2 | 187 | } |
54067ee2 | 188 | |
2f60ba70 | 189 | static int i2c_device_pm_suspend(struct device *dev) |
6de468ae | 190 | { |
2f60ba70 | 191 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 192 | |
2f60ba70 | 193 | if (pm_runtime_suspended(dev)) |
6de468ae | 194 | return 0; |
6de468ae | 195 | |
2f60ba70 RW |
196 | if (pm) |
197 | return pm->suspend ? pm->suspend(dev) : 0; | |
6de468ae | 198 | |
2f60ba70 | 199 | return i2c_legacy_suspend(dev, PMSG_SUSPEND); |
6de468ae MB |
200 | } |
201 | ||
2f60ba70 | 202 | static int i2c_device_pm_resume(struct device *dev) |
6de468ae | 203 | { |
2f60ba70 | 204 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae MB |
205 | int ret; |
206 | ||
2f60ba70 RW |
207 | if (pm) |
208 | ret = pm->resume ? pm->resume(dev) : 0; | |
209 | else | |
210 | ret = i2c_legacy_resume(dev); | |
211 | ||
212 | if (!ret) { | |
213 | pm_runtime_disable(dev); | |
214 | pm_runtime_set_active(dev); | |
215 | pm_runtime_enable(dev); | |
6de468ae MB |
216 | } |
217 | ||
2f60ba70 | 218 | return ret; |
6de468ae | 219 | } |
6de468ae | 220 | |
2f60ba70 | 221 | static int i2c_device_pm_freeze(struct device *dev) |
1da177e4 | 222 | { |
2f60ba70 | 223 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 224 | |
2f60ba70 | 225 | if (pm_runtime_suspended(dev)) |
f37dd80a | 226 | return 0; |
2f60ba70 RW |
227 | |
228 | if (pm) | |
229 | return pm->freeze ? pm->freeze(dev) : 0; | |
230 | ||
231 | return i2c_legacy_suspend(dev, PMSG_FREEZE); | |
1da177e4 LT |
232 | } |
233 | ||
2f60ba70 | 234 | static int i2c_device_pm_thaw(struct device *dev) |
1da177e4 | 235 | { |
2f60ba70 | 236 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 237 | |
2f60ba70 | 238 | if (pm_runtime_suspended(dev)) |
f37dd80a | 239 | return 0; |
2f60ba70 RW |
240 | |
241 | if (pm) | |
242 | return pm->thaw ? pm->thaw(dev) : 0; | |
243 | ||
244 | return i2c_legacy_resume(dev); | |
245 | } | |
246 | ||
247 | static int i2c_device_pm_poweroff(struct device *dev) | |
248 | { | |
249 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
250 | ||
251 | if (pm_runtime_suspended(dev)) | |
f37dd80a | 252 | return 0; |
2f60ba70 RW |
253 | |
254 | if (pm) | |
255 | return pm->poweroff ? pm->poweroff(dev) : 0; | |
256 | ||
257 | return i2c_legacy_suspend(dev, PMSG_HIBERNATE); | |
258 | } | |
259 | ||
260 | static int i2c_device_pm_restore(struct device *dev) | |
261 | { | |
262 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
263 | int ret; | |
264 | ||
265 | if (pm) | |
266 | ret = pm->restore ? pm->restore(dev) : 0; | |
267 | else | |
268 | ret = i2c_legacy_resume(dev); | |
269 | ||
270 | if (!ret) { | |
271 | pm_runtime_disable(dev); | |
272 | pm_runtime_set_active(dev); | |
273 | pm_runtime_enable(dev); | |
274 | } | |
275 | ||
276 | return ret; | |
1da177e4 | 277 | } |
2f60ba70 RW |
278 | #else /* !CONFIG_PM_SLEEP */ |
279 | #define i2c_device_pm_suspend NULL | |
280 | #define i2c_device_pm_resume NULL | |
281 | #define i2c_device_pm_freeze NULL | |
282 | #define i2c_device_pm_thaw NULL | |
283 | #define i2c_device_pm_poweroff NULL | |
284 | #define i2c_device_pm_restore NULL | |
285 | #endif /* !CONFIG_PM_SLEEP */ | |
1da177e4 | 286 | |
9c1600ed DB |
287 | static void i2c_client_dev_release(struct device *dev) |
288 | { | |
289 | kfree(to_i2c_client(dev)); | |
290 | } | |
291 | ||
09b8ce0a | 292 | static ssize_t |
4f8cf824 | 293 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 294 | { |
4f8cf824 JD |
295 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
296 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 DB |
297 | } |
298 | ||
09b8ce0a ZX |
299 | static ssize_t |
300 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
301 | { |
302 | struct i2c_client *client = to_i2c_client(dev); | |
eb8a7908 | 303 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
304 | } |
305 | ||
4f8cf824 | 306 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
51298d12 JD |
307 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
308 | ||
309 | static struct attribute *i2c_dev_attrs[] = { | |
310 | &dev_attr_name.attr, | |
7b4fbc50 | 311 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
312 | &dev_attr_modalias.attr, |
313 | NULL | |
314 | }; | |
315 | ||
316 | static struct attribute_group i2c_dev_attr_group = { | |
317 | .attrs = i2c_dev_attrs, | |
318 | }; | |
319 | ||
320 | static const struct attribute_group *i2c_dev_attr_groups[] = { | |
321 | &i2c_dev_attr_group, | |
322 | NULL | |
7b4fbc50 DB |
323 | }; |
324 | ||
0b2c3688 | 325 | static const struct dev_pm_ops i2c_device_pm_ops = { |
54067ee2 | 326 | .suspend = i2c_device_pm_suspend, |
327 | .resume = i2c_device_pm_resume, | |
2f60ba70 RW |
328 | .freeze = i2c_device_pm_freeze, |
329 | .thaw = i2c_device_pm_thaw, | |
330 | .poweroff = i2c_device_pm_poweroff, | |
331 | .restore = i2c_device_pm_restore, | |
332 | SET_RUNTIME_PM_OPS( | |
333 | pm_generic_runtime_suspend, | |
334 | pm_generic_runtime_resume, | |
335 | pm_generic_runtime_idle | |
336 | ) | |
54067ee2 | 337 | }; |
338 | ||
e9ca9eb9 | 339 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
340 | .name = "i2c", |
341 | .match = i2c_device_match, | |
342 | .probe = i2c_device_probe, | |
343 | .remove = i2c_device_remove, | |
344 | .shutdown = i2c_device_shutdown, | |
54067ee2 | 345 | .pm = &i2c_device_pm_ops, |
b864c7d5 | 346 | }; |
e9ca9eb9 | 347 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 348 | |
51298d12 JD |
349 | static struct device_type i2c_client_type = { |
350 | .groups = i2c_dev_attr_groups, | |
351 | .uevent = i2c_device_uevent, | |
352 | .release = i2c_client_dev_release, | |
353 | }; | |
354 | ||
9b766b81 DB |
355 | |
356 | /** | |
357 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
358 | * @dev: device, probably from some driver model iterator | |
359 | * | |
360 | * When traversing the driver model tree, perhaps using driver model | |
361 | * iterators like @device_for_each_child(), you can't assume very much | |
362 | * about the nodes you find. Use this function to avoid oopses caused | |
363 | * by wrongly treating some non-I2C device as an i2c_client. | |
364 | */ | |
365 | struct i2c_client *i2c_verify_client(struct device *dev) | |
366 | { | |
51298d12 | 367 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
368 | ? to_i2c_client(dev) |
369 | : NULL; | |
370 | } | |
371 | EXPORT_SYMBOL(i2c_verify_client); | |
372 | ||
373 | ||
9c1600ed | 374 | /** |
f8a227e8 | 375 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
376 | * @adap: the adapter managing the device |
377 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 378 | * Context: can sleep |
9c1600ed | 379 | * |
f8a227e8 JD |
380 | * Create an i2c device. Binding is handled through driver model |
381 | * probe()/remove() methods. A driver may be bound to this device when we | |
382 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
383 | * load the driver module). This call is not appropriate for use by mainboard | |
384 | * initialization logic, which usually runs during an arch_initcall() long | |
385 | * before any i2c_adapter could exist. | |
9c1600ed DB |
386 | * |
387 | * This returns the new i2c client, which may be saved for later use with | |
388 | * i2c_unregister_device(); or NULL to indicate an error. | |
389 | */ | |
390 | struct i2c_client * | |
391 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
392 | { | |
393 | struct i2c_client *client; | |
394 | int status; | |
395 | ||
396 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
397 | if (!client) | |
398 | return NULL; | |
399 | ||
400 | client->adapter = adap; | |
401 | ||
402 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 403 | |
11f1f2af AV |
404 | if (info->archdata) |
405 | client->dev.archdata = *info->archdata; | |
406 | ||
ee35425c | 407 | client->flags = info->flags; |
9c1600ed DB |
408 | client->addr = info->addr; |
409 | client->irq = info->irq; | |
410 | ||
9c1600ed DB |
411 | strlcpy(client->name, info->type, sizeof(client->name)); |
412 | ||
f8a227e8 JD |
413 | /* Check for address business */ |
414 | status = i2c_check_addr(adap, client->addr); | |
415 | if (status) | |
416 | goto out_err; | |
417 | ||
418 | client->dev.parent = &client->adapter->dev; | |
419 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 420 | client->dev.type = &i2c_client_type; |
f8a227e8 JD |
421 | |
422 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), | |
423 | client->addr); | |
424 | status = device_register(&client->dev); | |
425 | if (status) | |
426 | goto out_err; | |
427 | ||
f8a227e8 JD |
428 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
429 | client->name, dev_name(&client->dev)); | |
430 | ||
9c1600ed | 431 | return client; |
f8a227e8 JD |
432 | |
433 | out_err: | |
434 | dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " | |
435 | "(%d)\n", client->name, client->addr, status); | |
436 | kfree(client); | |
437 | return NULL; | |
9c1600ed DB |
438 | } |
439 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
440 | ||
441 | ||
442 | /** | |
443 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
444 | * @client: value returned from i2c_new_device() | |
d64f73be | 445 | * Context: can sleep |
9c1600ed DB |
446 | */ |
447 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 448 | { |
a1d9e6e4 DB |
449 | device_unregister(&client->dev); |
450 | } | |
9c1600ed | 451 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
452 | |
453 | ||
60b129d7 JD |
454 | static const struct i2c_device_id dummy_id[] = { |
455 | { "dummy", 0 }, | |
456 | { }, | |
457 | }; | |
458 | ||
d2653e92 JD |
459 | static int dummy_probe(struct i2c_client *client, |
460 | const struct i2c_device_id *id) | |
461 | { | |
462 | return 0; | |
463 | } | |
464 | ||
465 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
466 | { |
467 | return 0; | |
468 | } | |
469 | ||
470 | static struct i2c_driver dummy_driver = { | |
471 | .driver.name = "dummy", | |
d2653e92 JD |
472 | .probe = dummy_probe, |
473 | .remove = dummy_remove, | |
60b129d7 | 474 | .id_table = dummy_id, |
e9f1373b DB |
475 | }; |
476 | ||
477 | /** | |
478 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
479 | * @adapter: the adapter managing the device | |
480 | * @address: seven bit address to be used | |
e9f1373b DB |
481 | * Context: can sleep |
482 | * | |
483 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
484 | * with devices that consume multiple addresses. Examples of such chips | |
485 | * include various EEPROMS (like 24c04 and 24c08 models). | |
486 | * | |
487 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
488 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
489 | * And second, this prevents the specified address from being bound to a | |
490 | * different driver. | |
491 | * | |
492 | * This returns the new i2c client, which should be saved for later use with | |
493 | * i2c_unregister_device(); or NULL to indicate an error. | |
494 | */ | |
09b8ce0a | 495 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
496 | { |
497 | struct i2c_board_info info = { | |
60b129d7 | 498 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
499 | }; |
500 | ||
e9f1373b DB |
501 | return i2c_new_device(adapter, &info); |
502 | } | |
503 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
504 | ||
f37dd80a DB |
505 | /* ------------------------------------------------------------------------- */ |
506 | ||
16ffadfc DB |
507 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
508 | ||
83eaaed0 | 509 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 510 | { |
ef2c8321 | 511 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
512 | complete(&adap->dev_released); |
513 | } | |
514 | ||
99cd8e25 JD |
515 | /* |
516 | * Let users instantiate I2C devices through sysfs. This can be used when | |
517 | * platform initialization code doesn't contain the proper data for | |
518 | * whatever reason. Also useful for drivers that do device detection and | |
519 | * detection fails, either because the device uses an unexpected address, | |
520 | * or this is a compatible device with different ID register values. | |
521 | * | |
522 | * Parameter checking may look overzealous, but we really don't want | |
523 | * the user to provide incorrect parameters. | |
524 | */ | |
525 | static ssize_t | |
526 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
527 | const char *buf, size_t count) | |
528 | { | |
529 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
530 | struct i2c_board_info info; | |
531 | struct i2c_client *client; | |
532 | char *blank, end; | |
533 | int res; | |
534 | ||
535 | dev_warn(dev, "The new_device interface is still experimental " | |
536 | "and may change in a near future\n"); | |
537 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
538 | ||
539 | blank = strchr(buf, ' '); | |
540 | if (!blank) { | |
541 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
542 | return -EINVAL; | |
543 | } | |
544 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
545 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
546 | return -EINVAL; | |
547 | } | |
548 | memcpy(info.type, buf, blank - buf); | |
549 | ||
550 | /* Parse remaining parameters, reject extra parameters */ | |
551 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
552 | if (res < 1) { | |
553 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
554 | return -EINVAL; | |
555 | } | |
556 | if (res > 1 && end != '\n') { | |
557 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
558 | return -EINVAL; | |
559 | } | |
560 | ||
561 | if (info.addr < 0x03 || info.addr > 0x77) { | |
562 | dev_err(dev, "%s: Invalid I2C address 0x%hx\n", "new_device", | |
563 | info.addr); | |
564 | return -EINVAL; | |
565 | } | |
566 | ||
567 | client = i2c_new_device(adap, &info); | |
568 | if (!client) | |
569 | return -EEXIST; | |
570 | ||
571 | /* Keep track of the added device */ | |
6629dcff JD |
572 | i2c_lock_adapter(adap); |
573 | list_add_tail(&client->detected, &adap->userspace_clients); | |
574 | i2c_unlock_adapter(adap); | |
99cd8e25 JD |
575 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
576 | info.type, info.addr); | |
577 | ||
578 | return count; | |
579 | } | |
580 | ||
581 | /* | |
582 | * And of course let the users delete the devices they instantiated, if | |
583 | * they got it wrong. This interface can only be used to delete devices | |
584 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
585 | * don't delete devices to which some kernel code still has references. | |
586 | * | |
587 | * Parameter checking may look overzealous, but we really don't want | |
588 | * the user to delete the wrong device. | |
589 | */ | |
590 | static ssize_t | |
591 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
592 | const char *buf, size_t count) | |
593 | { | |
594 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
595 | struct i2c_client *client, *next; | |
596 | unsigned short addr; | |
597 | char end; | |
598 | int res; | |
599 | ||
600 | /* Parse parameters, reject extra parameters */ | |
601 | res = sscanf(buf, "%hi%c", &addr, &end); | |
602 | if (res < 1) { | |
603 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
604 | return -EINVAL; | |
605 | } | |
606 | if (res > 1 && end != '\n') { | |
607 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
608 | return -EINVAL; | |
609 | } | |
610 | ||
611 | /* Make sure the device was added through sysfs */ | |
612 | res = -ENOENT; | |
6629dcff JD |
613 | i2c_lock_adapter(adap); |
614 | list_for_each_entry_safe(client, next, &adap->userspace_clients, | |
615 | detected) { | |
616 | if (client->addr == addr) { | |
99cd8e25 JD |
617 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
618 | "delete_device", client->name, client->addr); | |
619 | ||
620 | list_del(&client->detected); | |
621 | i2c_unregister_device(client); | |
622 | res = count; | |
623 | break; | |
624 | } | |
625 | } | |
6629dcff | 626 | i2c_unlock_adapter(adap); |
99cd8e25 JD |
627 | |
628 | if (res < 0) | |
629 | dev_err(dev, "%s: Can't find device in list\n", | |
630 | "delete_device"); | |
631 | return res; | |
632 | } | |
633 | ||
4f8cf824 JD |
634 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
635 | static DEVICE_ATTR(delete_device, S_IWUSR, NULL, i2c_sysfs_delete_device); | |
636 | ||
637 | static struct attribute *i2c_adapter_attrs[] = { | |
638 | &dev_attr_name.attr, | |
639 | &dev_attr_new_device.attr, | |
640 | &dev_attr_delete_device.attr, | |
641 | NULL | |
642 | }; | |
643 | ||
644 | static struct attribute_group i2c_adapter_attr_group = { | |
645 | .attrs = i2c_adapter_attrs, | |
646 | }; | |
647 | ||
648 | static const struct attribute_group *i2c_adapter_attr_groups[] = { | |
649 | &i2c_adapter_attr_group, | |
650 | NULL | |
16ffadfc | 651 | }; |
b119dc3f | 652 | |
4f8cf824 JD |
653 | static struct device_type i2c_adapter_type = { |
654 | .groups = i2c_adapter_attr_groups, | |
655 | .release = i2c_adapter_dev_release, | |
1da177e4 LT |
656 | }; |
657 | ||
2bb5095a JD |
658 | #ifdef CONFIG_I2C_COMPAT |
659 | static struct class_compat *i2c_adapter_compat_class; | |
660 | #endif | |
661 | ||
9c1600ed DB |
662 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
663 | { | |
664 | struct i2c_devinfo *devinfo; | |
665 | ||
f18c41da | 666 | down_read(&__i2c_board_lock); |
9c1600ed DB |
667 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
668 | if (devinfo->busnum == adapter->nr | |
669 | && !i2c_new_device(adapter, | |
670 | &devinfo->board_info)) | |
09b8ce0a ZX |
671 | dev_err(&adapter->dev, |
672 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
673 | devinfo->board_info.addr); |
674 | } | |
f18c41da | 675 | up_read(&__i2c_board_lock); |
9c1600ed DB |
676 | } |
677 | ||
69b0089a JD |
678 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
679 | struct i2c_adapter *adap) | |
026526f5 | 680 | { |
4735c98f JD |
681 | /* Detect supported devices on that bus, and instantiate them */ |
682 | i2c_detect(adap, driver); | |
683 | ||
684 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 JD |
685 | if (driver->attach_adapter) { |
686 | /* We ignore the return code; if it fails, too bad */ | |
687 | driver->attach_adapter(adap); | |
688 | } | |
689 | return 0; | |
690 | } | |
691 | ||
69b0089a JD |
692 | static int __process_new_adapter(struct device_driver *d, void *data) |
693 | { | |
694 | return i2c_do_add_adapter(to_i2c_driver(d), data); | |
695 | } | |
696 | ||
6e13e641 | 697 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 698 | { |
026526f5 | 699 | int res = 0, dummy; |
1da177e4 | 700 | |
1d0b19c9 | 701 | /* Can't register until after driver model init */ |
35fc37f8 JD |
702 | if (unlikely(WARN_ON(!i2c_bus_type.p))) { |
703 | res = -EAGAIN; | |
704 | goto out_list; | |
705 | } | |
1d0b19c9 | 706 | |
194684e5 | 707 | rt_mutex_init(&adap->bus_lock); |
6629dcff | 708 | INIT_LIST_HEAD(&adap->userspace_clients); |
1da177e4 | 709 | |
8fcfef6e JD |
710 | /* Set default timeout to 1 second if not already set */ |
711 | if (adap->timeout == 0) | |
712 | adap->timeout = HZ; | |
713 | ||
27d9c183 | 714 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
715 | adap->dev.bus = &i2c_bus_type; |
716 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 JD |
717 | res = device_register(&adap->dev); |
718 | if (res) | |
719 | goto out_list; | |
1da177e4 | 720 | |
b6d7b3d1 JD |
721 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
722 | ||
2bb5095a JD |
723 | #ifdef CONFIG_I2C_COMPAT |
724 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
725 | adap->dev.parent); | |
726 | if (res) | |
727 | dev_warn(&adap->dev, | |
728 | "Failed to create compatibility class link\n"); | |
729 | #endif | |
730 | ||
729d6dd5 | 731 | /* create pre-declared device nodes */ |
6e13e641 DB |
732 | if (adap->nr < __i2c_first_dynamic_bus_num) |
733 | i2c_scan_static_board_info(adap); | |
734 | ||
4735c98f | 735 | /* Notify drivers */ |
35fc37f8 | 736 | mutex_lock(&core_lock); |
026526f5 | 737 | dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 738 | __process_new_adapter); |
caada32a | 739 | mutex_unlock(&core_lock); |
35fc37f8 JD |
740 | |
741 | return 0; | |
b119c6c9 | 742 | |
b119c6c9 | 743 | out_list: |
35fc37f8 | 744 | mutex_lock(&core_lock); |
b119c6c9 | 745 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
746 | mutex_unlock(&core_lock); |
747 | return res; | |
1da177e4 LT |
748 | } |
749 | ||
6e13e641 DB |
750 | /** |
751 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
752 | * @adapter: the adapter to add | |
d64f73be | 753 | * Context: can sleep |
6e13e641 DB |
754 | * |
755 | * This routine is used to declare an I2C adapter when its bus number | |
756 | * doesn't matter. Examples: for I2C adapters dynamically added by | |
757 | * USB links or PCI plugin cards. | |
758 | * | |
759 | * When this returns zero, a new bus number was allocated and stored | |
760 | * in adap->nr, and the specified adapter became available for clients. | |
761 | * Otherwise, a negative errno value is returned. | |
762 | */ | |
763 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
764 | { | |
765 | int id, res = 0; | |
766 | ||
767 | retry: | |
768 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
769 | return -ENOMEM; | |
770 | ||
caada32a | 771 | mutex_lock(&core_lock); |
6e13e641 DB |
772 | /* "above" here means "above or equal to", sigh */ |
773 | res = idr_get_new_above(&i2c_adapter_idr, adapter, | |
774 | __i2c_first_dynamic_bus_num, &id); | |
caada32a | 775 | mutex_unlock(&core_lock); |
6e13e641 DB |
776 | |
777 | if (res < 0) { | |
778 | if (res == -EAGAIN) | |
779 | goto retry; | |
780 | return res; | |
781 | } | |
782 | ||
783 | adapter->nr = id; | |
784 | return i2c_register_adapter(adapter); | |
785 | } | |
786 | EXPORT_SYMBOL(i2c_add_adapter); | |
787 | ||
788 | /** | |
789 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
790 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 791 | * Context: can sleep |
6e13e641 DB |
792 | * |
793 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
794 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
795 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
796 | * is used to properly configure I2C devices. |
797 | * | |
798 | * If no devices have pre-been declared for this bus, then be sure to | |
799 | * register the adapter before any dynamically allocated ones. Otherwise | |
800 | * the required bus ID may not be available. | |
801 | * | |
802 | * When this returns zero, the specified adapter became available for | |
803 | * clients using the bus number provided in adap->nr. Also, the table | |
804 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
805 | * and the appropriate driver model device nodes are created. Otherwise, a | |
806 | * negative errno value is returned. | |
807 | */ | |
808 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
809 | { | |
810 | int id; | |
811 | int status; | |
812 | ||
813 | if (adap->nr & ~MAX_ID_MASK) | |
814 | return -EINVAL; | |
815 | ||
816 | retry: | |
817 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
818 | return -ENOMEM; | |
819 | ||
caada32a | 820 | mutex_lock(&core_lock); |
6e13e641 DB |
821 | /* "above" here means "above or equal to", sigh; |
822 | * we need the "equal to" result to force the result | |
823 | */ | |
824 | status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id); | |
825 | if (status == 0 && id != adap->nr) { | |
826 | status = -EBUSY; | |
827 | idr_remove(&i2c_adapter_idr, id); | |
828 | } | |
caada32a | 829 | mutex_unlock(&core_lock); |
6e13e641 DB |
830 | if (status == -EAGAIN) |
831 | goto retry; | |
832 | ||
833 | if (status == 0) | |
834 | status = i2c_register_adapter(adap); | |
835 | return status; | |
836 | } | |
837 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
838 | ||
69b0089a JD |
839 | static int i2c_do_del_adapter(struct i2c_driver *driver, |
840 | struct i2c_adapter *adapter) | |
026526f5 | 841 | { |
4735c98f | 842 | struct i2c_client *client, *_n; |
026526f5 JD |
843 | int res; |
844 | ||
acec211c JD |
845 | /* Remove the devices we created ourselves as the result of hardware |
846 | * probing (using a driver's detect method) */ | |
4735c98f JD |
847 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
848 | if (client->adapter == adapter) { | |
849 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
850 | client->name, client->addr); | |
851 | list_del(&client->detected); | |
852 | i2c_unregister_device(client); | |
853 | } | |
854 | } | |
855 | ||
026526f5 JD |
856 | if (!driver->detach_adapter) |
857 | return 0; | |
858 | res = driver->detach_adapter(adapter); | |
859 | if (res) | |
860 | dev_err(&adapter->dev, "detach_adapter failed (%d) " | |
861 | "for driver [%s]\n", res, driver->driver.name); | |
862 | return res; | |
863 | } | |
864 | ||
e549c2b5 JD |
865 | static int __unregister_client(struct device *dev, void *dummy) |
866 | { | |
867 | struct i2c_client *client = i2c_verify_client(dev); | |
868 | if (client) | |
869 | i2c_unregister_device(client); | |
870 | return 0; | |
871 | } | |
872 | ||
69b0089a JD |
873 | static int __process_removed_adapter(struct device_driver *d, void *data) |
874 | { | |
875 | return i2c_do_del_adapter(to_i2c_driver(d), data); | |
876 | } | |
877 | ||
d64f73be DB |
878 | /** |
879 | * i2c_del_adapter - unregister I2C adapter | |
880 | * @adap: the adapter being unregistered | |
881 | * Context: can sleep | |
882 | * | |
883 | * This unregisters an I2C adapter which was previously registered | |
884 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
885 | */ | |
1da177e4 LT |
886 | int i2c_del_adapter(struct i2c_adapter *adap) |
887 | { | |
1da177e4 | 888 | int res = 0; |
35fc37f8 | 889 | struct i2c_adapter *found; |
bbd2d9c9 | 890 | struct i2c_client *client, *next; |
1da177e4 LT |
891 | |
892 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
893 | mutex_lock(&core_lock); |
894 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
895 | mutex_unlock(&core_lock); | |
896 | if (found != adap) { | |
b6d7b3d1 JD |
897 | pr_debug("i2c-core: attempting to delete unregistered " |
898 | "adapter [%s]\n", adap->name); | |
35fc37f8 | 899 | return -EINVAL; |
1da177e4 LT |
900 | } |
901 | ||
026526f5 | 902 | /* Tell drivers about this removal */ |
35fc37f8 | 903 | mutex_lock(&core_lock); |
026526f5 | 904 | res = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 905 | __process_removed_adapter); |
35fc37f8 | 906 | mutex_unlock(&core_lock); |
026526f5 | 907 | if (res) |
35fc37f8 | 908 | return res; |
1da177e4 | 909 | |
bbd2d9c9 | 910 | /* Remove devices instantiated from sysfs */ |
6629dcff JD |
911 | i2c_lock_adapter(adap); |
912 | list_for_each_entry_safe(client, next, &adap->userspace_clients, | |
913 | detected) { | |
914 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, | |
915 | client->addr); | |
916 | list_del(&client->detected); | |
917 | i2c_unregister_device(client); | |
bbd2d9c9 | 918 | } |
6629dcff | 919 | i2c_unlock_adapter(adap); |
bbd2d9c9 | 920 | |
e549c2b5 JD |
921 | /* Detach any active clients. This can't fail, thus we do not |
922 | checking the returned value. */ | |
923 | res = device_for_each_child(&adap->dev, NULL, __unregister_client); | |
1da177e4 | 924 | |
2bb5095a JD |
925 | #ifdef CONFIG_I2C_COMPAT |
926 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
927 | adap->dev.parent); | |
928 | #endif | |
929 | ||
c5567521 TLSC |
930 | /* device name is gone after device_unregister */ |
931 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); | |
932 | ||
1da177e4 LT |
933 | /* clean up the sysfs representation */ |
934 | init_completion(&adap->dev_released); | |
1da177e4 | 935 | device_unregister(&adap->dev); |
1da177e4 LT |
936 | |
937 | /* wait for sysfs to drop all references */ | |
938 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 939 | |
6e13e641 | 940 | /* free bus id */ |
35fc37f8 | 941 | mutex_lock(&core_lock); |
1da177e4 | 942 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 943 | mutex_unlock(&core_lock); |
1da177e4 | 944 | |
bd4bc3db JD |
945 | /* Clear the device structure in case this adapter is ever going to be |
946 | added again */ | |
947 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
948 | ||
35fc37f8 | 949 | return 0; |
1da177e4 | 950 | } |
c0564606 | 951 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 LT |
952 | |
953 | ||
7b4fbc50 DB |
954 | /* ------------------------------------------------------------------------- */ |
955 | ||
69b0089a | 956 | static int __process_new_driver(struct device *dev, void *data) |
7f101a97 | 957 | { |
4f8cf824 JD |
958 | if (dev->type != &i2c_adapter_type) |
959 | return 0; | |
69b0089a | 960 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
7f101a97 DY |
961 | } |
962 | ||
7b4fbc50 DB |
963 | /* |
964 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 965 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
966 | */ |
967 | ||
de59cf9e | 968 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 969 | { |
7eebcb7c | 970 | int res; |
1da177e4 | 971 | |
1d0b19c9 DB |
972 | /* Can't register until after driver model init */ |
973 | if (unlikely(WARN_ON(!i2c_bus_type.p))) | |
974 | return -EAGAIN; | |
975 | ||
1da177e4 | 976 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 977 | driver->driver.owner = owner; |
1da177e4 | 978 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 979 | |
729d6dd5 | 980 | /* When registration returns, the driver core |
6e13e641 DB |
981 | * will have called probe() for all matching-but-unbound devices. |
982 | */ | |
1da177e4 LT |
983 | res = driver_register(&driver->driver); |
984 | if (res) | |
7eebcb7c | 985 | return res; |
438d6c2c | 986 | |
35d8b2e6 | 987 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 988 | |
4735c98f JD |
989 | INIT_LIST_HEAD(&driver->clients); |
990 | /* Walk the adapters that are already present */ | |
35fc37f8 | 991 | mutex_lock(&core_lock); |
69b0089a | 992 | bus_for_each_dev(&i2c_bus_type, NULL, driver, __process_new_driver); |
7f101a97 | 993 | mutex_unlock(&core_lock); |
35fc37f8 | 994 | |
7f101a97 DY |
995 | return 0; |
996 | } | |
997 | EXPORT_SYMBOL(i2c_register_driver); | |
998 | ||
69b0089a | 999 | static int __process_removed_driver(struct device *dev, void *data) |
7f101a97 | 1000 | { |
4f8cf824 JD |
1001 | if (dev->type != &i2c_adapter_type) |
1002 | return 0; | |
69b0089a | 1003 | return i2c_do_del_adapter(data, to_i2c_adapter(dev)); |
1da177e4 LT |
1004 | } |
1005 | ||
a1d9e6e4 DB |
1006 | /** |
1007 | * i2c_del_driver - unregister I2C driver | |
1008 | * @driver: the driver being unregistered | |
d64f73be | 1009 | * Context: can sleep |
a1d9e6e4 | 1010 | */ |
b3e82096 | 1011 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 1012 | { |
caada32a | 1013 | mutex_lock(&core_lock); |
69b0089a | 1014 | bus_for_each_dev(&i2c_bus_type, NULL, driver, __process_removed_driver); |
35fc37f8 | 1015 | mutex_unlock(&core_lock); |
1da177e4 LT |
1016 | |
1017 | driver_unregister(&driver->driver); | |
35d8b2e6 | 1018 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 1019 | } |
c0564606 | 1020 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 1021 | |
7b4fbc50 DB |
1022 | /* ------------------------------------------------------------------------- */ |
1023 | ||
9b766b81 | 1024 | static int __i2c_check_addr(struct device *dev, void *addrp) |
1da177e4 | 1025 | { |
9b766b81 DB |
1026 | struct i2c_client *client = i2c_verify_client(dev); |
1027 | int addr = *(int *)addrp; | |
1da177e4 | 1028 | |
9b766b81 DB |
1029 | if (client && client->addr == addr) |
1030 | return -EBUSY; | |
1da177e4 LT |
1031 | return 0; |
1032 | } | |
1033 | ||
5e31c2bd | 1034 | static int i2c_check_addr(struct i2c_adapter *adapter, int addr) |
1da177e4 | 1035 | { |
9b766b81 | 1036 | return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr); |
1da177e4 LT |
1037 | } |
1038 | ||
e48d3319 JD |
1039 | /** |
1040 | * i2c_use_client - increments the reference count of the i2c client structure | |
1041 | * @client: the client being referenced | |
1042 | * | |
1043 | * Each live reference to a client should be refcounted. The driver model does | |
1044 | * that automatically as part of driver binding, so that most drivers don't | |
1045 | * need to do this explicitly: they hold a reference until they're unbound | |
1046 | * from the device. | |
1047 | * | |
1048 | * A pointer to the client with the incremented reference counter is returned. | |
1049 | */ | |
1050 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 1051 | { |
6ea438ec DB |
1052 | if (client && get_device(&client->dev)) |
1053 | return client; | |
1054 | return NULL; | |
1da177e4 | 1055 | } |
c0564606 | 1056 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 1057 | |
e48d3319 JD |
1058 | /** |
1059 | * i2c_release_client - release a use of the i2c client structure | |
1060 | * @client: the client being no longer referenced | |
1061 | * | |
1062 | * Must be called when a user of a client is finished with it. | |
1063 | */ | |
1064 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 1065 | { |
6ea438ec DB |
1066 | if (client) |
1067 | put_device(&client->dev); | |
1da177e4 | 1068 | } |
c0564606 | 1069 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 1070 | |
9b766b81 DB |
1071 | struct i2c_cmd_arg { |
1072 | unsigned cmd; | |
1073 | void *arg; | |
1074 | }; | |
1075 | ||
1076 | static int i2c_cmd(struct device *dev, void *_arg) | |
1077 | { | |
1078 | struct i2c_client *client = i2c_verify_client(dev); | |
1079 | struct i2c_cmd_arg *arg = _arg; | |
1080 | ||
1081 | if (client && client->driver && client->driver->command) | |
1082 | client->driver->command(client, arg->cmd, arg->arg); | |
1083 | return 0; | |
1084 | } | |
1085 | ||
1da177e4 LT |
1086 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
1087 | { | |
9b766b81 | 1088 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 1089 | |
9b766b81 DB |
1090 | cmd_arg.cmd = cmd; |
1091 | cmd_arg.arg = arg; | |
1092 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 1093 | } |
c0564606 | 1094 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
1095 | |
1096 | static int __init i2c_init(void) | |
1097 | { | |
1098 | int retval; | |
1099 | ||
1100 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
1101 | if (retval) |
1102 | return retval; | |
2bb5095a JD |
1103 | #ifdef CONFIG_I2C_COMPAT |
1104 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
1105 | if (!i2c_adapter_compat_class) { | |
1106 | retval = -ENOMEM; | |
1107 | goto bus_err; | |
1108 | } | |
1109 | #endif | |
e9f1373b DB |
1110 | retval = i2c_add_driver(&dummy_driver); |
1111 | if (retval) | |
2bb5095a | 1112 | goto class_err; |
e9f1373b DB |
1113 | return 0; |
1114 | ||
2bb5095a JD |
1115 | class_err: |
1116 | #ifdef CONFIG_I2C_COMPAT | |
1117 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 1118 | bus_err: |
2bb5095a | 1119 | #endif |
e9f1373b DB |
1120 | bus_unregister(&i2c_bus_type); |
1121 | return retval; | |
1da177e4 LT |
1122 | } |
1123 | ||
1124 | static void __exit i2c_exit(void) | |
1125 | { | |
e9f1373b | 1126 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
1127 | #ifdef CONFIG_I2C_COMPAT |
1128 | class_compat_unregister(i2c_adapter_compat_class); | |
1129 | #endif | |
1da177e4 LT |
1130 | bus_unregister(&i2c_bus_type); |
1131 | } | |
1132 | ||
a10f9e7c DB |
1133 | /* We must initialize early, because some subsystems register i2c drivers |
1134 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1135 | */ | |
1136 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1137 | module_exit(i2c_exit); |
1138 | ||
1139 | /* ---------------------------------------------------- | |
1140 | * the functional interface to the i2c busses. | |
1141 | * ---------------------------------------------------- | |
1142 | */ | |
1143 | ||
a1cdedac DB |
1144 | /** |
1145 | * i2c_transfer - execute a single or combined I2C message | |
1146 | * @adap: Handle to I2C bus | |
1147 | * @msgs: One or more messages to execute before STOP is issued to | |
1148 | * terminate the operation; each message begins with a START. | |
1149 | * @num: Number of messages to be executed. | |
1150 | * | |
1151 | * Returns negative errno, else the number of messages executed. | |
1152 | * | |
1153 | * Note that there is no requirement that each message be sent to | |
1154 | * the same slave address, although that is the most common model. | |
1155 | */ | |
09b8ce0a | 1156 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 1157 | { |
66b650f0 CW |
1158 | unsigned long orig_jiffies; |
1159 | int ret, try; | |
1da177e4 | 1160 | |
a1cdedac DB |
1161 | /* REVISIT the fault reporting model here is weak: |
1162 | * | |
1163 | * - When we get an error after receiving N bytes from a slave, | |
1164 | * there is no way to report "N". | |
1165 | * | |
1166 | * - When we get a NAK after transmitting N bytes to a slave, | |
1167 | * there is no way to report "N" ... or to let the master | |
1168 | * continue executing the rest of this combined message, if | |
1169 | * that's the appropriate response. | |
1170 | * | |
1171 | * - When for example "num" is two and we successfully complete | |
1172 | * the first message but get an error part way through the | |
1173 | * second, it's unclear whether that should be reported as | |
1174 | * one (discarding status on the second message) or errno | |
1175 | * (discarding status on the first one). | |
1176 | */ | |
1177 | ||
1da177e4 LT |
1178 | if (adap->algo->master_xfer) { |
1179 | #ifdef DEBUG | |
1180 | for (ret = 0; ret < num; ret++) { | |
1181 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
1182 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
1183 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
1184 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
1185 | } |
1186 | #endif | |
1187 | ||
cea443a8 | 1188 | if (in_atomic() || irqs_disabled()) { |
194684e5 | 1189 | ret = rt_mutex_trylock(&adap->bus_lock); |
cea443a8 MR |
1190 | if (!ret) |
1191 | /* I2C activity is ongoing. */ | |
1192 | return -EAGAIN; | |
1193 | } else { | |
194684e5 | 1194 | rt_mutex_lock(&adap->bus_lock); |
cea443a8 MR |
1195 | } |
1196 | ||
66b650f0 CW |
1197 | /* Retry automatically on arbitration loss */ |
1198 | orig_jiffies = jiffies; | |
1199 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
1200 | ret = adap->algo->master_xfer(adap, msgs, num); | |
1201 | if (ret != -EAGAIN) | |
1202 | break; | |
1203 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
1204 | break; | |
1205 | } | |
194684e5 | 1206 | rt_mutex_unlock(&adap->bus_lock); |
1da177e4 LT |
1207 | |
1208 | return ret; | |
1209 | } else { | |
1210 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1211 | return -EOPNOTSUPP; |
1da177e4 LT |
1212 | } |
1213 | } | |
c0564606 | 1214 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1215 | |
a1cdedac DB |
1216 | /** |
1217 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1218 | * @client: Handle to slave device | |
1219 | * @buf: Data that will be written to the slave | |
0c43ea54 | 1220 | * @count: How many bytes to write, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1221 | * |
1222 | * Returns negative errno, or else the number of bytes written. | |
1223 | */ | |
1da177e4 LT |
1224 | int i2c_master_send(struct i2c_client *client,const char *buf ,int count) |
1225 | { | |
1226 | int ret; | |
1227 | struct i2c_adapter *adap=client->adapter; | |
1228 | struct i2c_msg msg; | |
1229 | ||
815f55f2 JD |
1230 | msg.addr = client->addr; |
1231 | msg.flags = client->flags & I2C_M_TEN; | |
1232 | msg.len = count; | |
1233 | msg.buf = (char *)buf; | |
438d6c2c | 1234 | |
815f55f2 | 1235 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1236 | |
815f55f2 JD |
1237 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes |
1238 | transmitted, else error code. */ | |
1239 | return (ret == 1) ? count : ret; | |
1da177e4 | 1240 | } |
c0564606 | 1241 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1242 | |
a1cdedac DB |
1243 | /** |
1244 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1245 | * @client: Handle to slave device | |
1246 | * @buf: Where to store data read from slave | |
0c43ea54 | 1247 | * @count: How many bytes to read, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1248 | * |
1249 | * Returns negative errno, or else the number of bytes read. | |
1250 | */ | |
1da177e4 LT |
1251 | int i2c_master_recv(struct i2c_client *client, char *buf ,int count) |
1252 | { | |
1253 | struct i2c_adapter *adap=client->adapter; | |
1254 | struct i2c_msg msg; | |
1255 | int ret; | |
815f55f2 JD |
1256 | |
1257 | msg.addr = client->addr; | |
1258 | msg.flags = client->flags & I2C_M_TEN; | |
1259 | msg.flags |= I2C_M_RD; | |
1260 | msg.len = count; | |
1261 | msg.buf = buf; | |
1262 | ||
1263 | ret = i2c_transfer(adap, &msg, 1); | |
1264 | ||
1265 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1266 | transmitted, else error code. */ | |
1267 | return (ret == 1) ? count : ret; | |
1da177e4 | 1268 | } |
c0564606 | 1269 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1270 | |
1da177e4 LT |
1271 | /* ---------------------------------------------------- |
1272 | * the i2c address scanning function | |
1273 | * Will not work for 10-bit addresses! | |
1274 | * ---------------------------------------------------- | |
1275 | */ | |
1da177e4 | 1276 | |
ccfbbd08 | 1277 | static int i2c_detect_address(struct i2c_client *temp_client, |
4735c98f JD |
1278 | struct i2c_driver *driver) |
1279 | { | |
1280 | struct i2c_board_info info; | |
1281 | struct i2c_adapter *adapter = temp_client->adapter; | |
1282 | int addr = temp_client->addr; | |
1283 | int err; | |
1284 | ||
1285 | /* Make sure the address is valid */ | |
1286 | if (addr < 0x03 || addr > 0x77) { | |
1287 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", | |
1288 | addr); | |
1289 | return -EINVAL; | |
1290 | } | |
1291 | ||
1292 | /* Skip if already in use */ | |
1293 | if (i2c_check_addr(adapter, addr)) | |
1294 | return 0; | |
1295 | ||
ccfbbd08 | 1296 | /* Make sure there is something at this address */ |
b1d4b390 JD |
1297 | if (addr == 0x73 && (adapter->class & I2C_CLASS_HWMON)) { |
1298 | /* Special probe for FSC hwmon chips */ | |
1299 | union i2c_smbus_data dummy; | |
4735c98f | 1300 | |
b1d4b390 JD |
1301 | if (i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_READ, 0, |
1302 | I2C_SMBUS_BYTE_DATA, &dummy) < 0) | |
1303 | return 0; | |
1304 | } else { | |
1305 | if (i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_WRITE, 0, | |
1306 | I2C_SMBUS_QUICK, NULL) < 0) | |
1307 | return 0; | |
1308 | ||
1309 | /* Prevent 24RF08 corruption */ | |
1310 | if ((addr & ~0x0f) == 0x50) | |
1311 | i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_WRITE, 0, | |
1312 | I2C_SMBUS_QUICK, NULL); | |
1313 | } | |
4735c98f JD |
1314 | |
1315 | /* Finally call the custom detection function */ | |
1316 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
1317 | info.addr = addr; | |
310ec792 | 1318 | err = driver->detect(temp_client, &info); |
4735c98f JD |
1319 | if (err) { |
1320 | /* -ENODEV is returned if the detection fails. We catch it | |
1321 | here as this isn't an error. */ | |
1322 | return err == -ENODEV ? 0 : err; | |
1323 | } | |
1324 | ||
1325 | /* Consistency check */ | |
1326 | if (info.type[0] == '\0') { | |
1327 | dev_err(&adapter->dev, "%s detection function provided " | |
1328 | "no name for 0x%x\n", driver->driver.name, | |
1329 | addr); | |
1330 | } else { | |
1331 | struct i2c_client *client; | |
1332 | ||
1333 | /* Detection succeeded, instantiate the device */ | |
1334 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", | |
1335 | info.type, info.addr); | |
1336 | client = i2c_new_device(adapter, &info); | |
1337 | if (client) | |
1338 | list_add_tail(&client->detected, &driver->clients); | |
1339 | else | |
1340 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
1341 | info.type, info.addr); | |
1342 | } | |
1343 | return 0; | |
1344 | } | |
1345 | ||
1346 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
1347 | { | |
c3813d6a | 1348 | const unsigned short *address_list; |
4735c98f JD |
1349 | struct i2c_client *temp_client; |
1350 | int i, err = 0; | |
1351 | int adap_id = i2c_adapter_id(adapter); | |
1352 | ||
c3813d6a JD |
1353 | address_list = driver->address_list; |
1354 | if (!driver->detect || !address_list) | |
4735c98f JD |
1355 | return 0; |
1356 | ||
1357 | /* Set up a temporary client to help detect callback */ | |
1358 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
1359 | if (!temp_client) | |
1360 | return -ENOMEM; | |
1361 | temp_client->adapter = adapter; | |
1362 | ||
4329cf86 JD |
1363 | /* Stop here if the classes do not match */ |
1364 | if (!(adapter->class & driver->class)) | |
1365 | goto exit_free; | |
1366 | ||
4735c98f JD |
1367 | /* Stop here if we can't use SMBUS_QUICK */ |
1368 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) { | |
c3813d6a | 1369 | if (address_list[0] == I2C_CLIENT_END) |
4735c98f JD |
1370 | goto exit_free; |
1371 | ||
1372 | dev_warn(&adapter->dev, "SMBus Quick command not supported, " | |
1373 | "can't probe for chips\n"); | |
1374 | err = -EOPNOTSUPP; | |
1375 | goto exit_free; | |
1376 | } | |
1377 | ||
c3813d6a | 1378 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
4735c98f | 1379 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
c3813d6a JD |
1380 | "addr 0x%02x\n", adap_id, address_list[i]); |
1381 | temp_client->addr = address_list[i]; | |
ccfbbd08 | 1382 | err = i2c_detect_address(temp_client, driver); |
4735c98f JD |
1383 | if (err) |
1384 | goto exit_free; | |
1385 | } | |
1386 | ||
1387 | exit_free: | |
1388 | kfree(temp_client); | |
1389 | return err; | |
1390 | } | |
1391 | ||
12b5053a JD |
1392 | struct i2c_client * |
1393 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1394 | struct i2c_board_info *info, | |
1395 | unsigned short const *addr_list) | |
1396 | { | |
1397 | int i; | |
1398 | ||
1399 | /* Stop here if the bus doesn't support probing */ | |
1400 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { | |
1401 | dev_err(&adap->dev, "Probing not supported\n"); | |
1402 | return NULL; | |
1403 | } | |
1404 | ||
12b5053a JD |
1405 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1406 | /* Check address validity */ | |
1407 | if (addr_list[i] < 0x03 || addr_list[i] > 0x77) { | |
1408 | dev_warn(&adap->dev, "Invalid 7-bit address " | |
1409 | "0x%02x\n", addr_list[i]); | |
1410 | continue; | |
1411 | } | |
1412 | ||
1413 | /* Check address availability */ | |
9b766b81 | 1414 | if (i2c_check_addr(adap, addr_list[i])) { |
12b5053a JD |
1415 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1416 | "use, not probing\n", addr_list[i]); | |
1417 | continue; | |
1418 | } | |
1419 | ||
1420 | /* Test address responsiveness | |
1421 | The default probe method is a quick write, but it is known | |
1422 | to corrupt the 24RF08 EEPROMs due to a state machine bug, | |
1423 | and could also irreversibly write-protect some EEPROMs, so | |
1424 | for address ranges 0x30-0x37 and 0x50-0x5f, we use a byte | |
1425 | read instead. Also, some bus drivers don't implement | |
1426 | quick write, so we fallback to a byte read it that case | |
1427 | too. */ | |
1428 | if ((addr_list[i] & ~0x07) == 0x30 | |
1429 | || (addr_list[i] & ~0x0f) == 0x50 | |
1430 | || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) { | |
b25b791b HV |
1431 | union i2c_smbus_data data; |
1432 | ||
12b5053a JD |
1433 | if (i2c_smbus_xfer(adap, addr_list[i], 0, |
1434 | I2C_SMBUS_READ, 0, | |
b25b791b | 1435 | I2C_SMBUS_BYTE, &data) >= 0) |
12b5053a JD |
1436 | break; |
1437 | } else { | |
1438 | if (i2c_smbus_xfer(adap, addr_list[i], 0, | |
1439 | I2C_SMBUS_WRITE, 0, | |
1440 | I2C_SMBUS_QUICK, NULL) >= 0) | |
1441 | break; | |
1442 | } | |
1443 | } | |
12b5053a JD |
1444 | |
1445 | if (addr_list[i] == I2C_CLIENT_END) { | |
1446 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1447 | return NULL; | |
1448 | } | |
1449 | ||
1450 | info->addr = addr_list[i]; | |
1451 | return i2c_new_device(adap, info); | |
1452 | } | |
1453 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
1454 | ||
1da177e4 LT |
1455 | struct i2c_adapter* i2c_get_adapter(int id) |
1456 | { | |
1da177e4 | 1457 | struct i2c_adapter *adapter; |
438d6c2c | 1458 | |
caada32a | 1459 | mutex_lock(&core_lock); |
1cf92b45 | 1460 | adapter = idr_find(&i2c_adapter_idr, id); |
a0920e10 MH |
1461 | if (adapter && !try_module_get(adapter->owner)) |
1462 | adapter = NULL; | |
1463 | ||
caada32a | 1464 | mutex_unlock(&core_lock); |
a0920e10 | 1465 | return adapter; |
1da177e4 | 1466 | } |
c0564606 | 1467 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
1468 | |
1469 | void i2c_put_adapter(struct i2c_adapter *adap) | |
1470 | { | |
1471 | module_put(adap->owner); | |
1472 | } | |
c0564606 | 1473 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
1474 | |
1475 | /* The SMBus parts */ | |
1476 | ||
438d6c2c | 1477 | #define POLY (0x1070U << 3) |
09b8ce0a | 1478 | static u8 crc8(u16 data) |
1da177e4 LT |
1479 | { |
1480 | int i; | |
438d6c2c | 1481 | |
1da177e4 | 1482 | for(i = 0; i < 8; i++) { |
438d6c2c | 1483 | if (data & 0x8000) |
1da177e4 LT |
1484 | data = data ^ POLY; |
1485 | data = data << 1; | |
1486 | } | |
1487 | return (u8)(data >> 8); | |
1488 | } | |
1489 | ||
421ef47b JD |
1490 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
1491 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
1492 | { |
1493 | int i; | |
1494 | ||
1495 | for(i = 0; i < count; i++) | |
421ef47b | 1496 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
1497 | return crc; |
1498 | } | |
1499 | ||
421ef47b JD |
1500 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
1501 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 1502 | { |
421ef47b JD |
1503 | /* The address will be sent first */ |
1504 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
1505 | pec = i2c_smbus_pec(pec, &addr, 1); | |
1506 | ||
1507 | /* The data buffer follows */ | |
1508 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
1509 | } |
1510 | ||
421ef47b JD |
1511 | /* Used for write only transactions */ |
1512 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 1513 | { |
421ef47b JD |
1514 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
1515 | msg->len++; | |
1da177e4 LT |
1516 | } |
1517 | ||
421ef47b JD |
1518 | /* Return <0 on CRC error |
1519 | If there was a write before this read (most cases) we need to take the | |
1520 | partial CRC from the write part into account. | |
1521 | Note that this function does modify the message (we need to decrease the | |
1522 | message length to hide the CRC byte from the caller). */ | |
1523 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 1524 | { |
421ef47b JD |
1525 | u8 rpec = msg->buf[--msg->len]; |
1526 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 1527 | |
1da177e4 LT |
1528 | if (rpec != cpec) { |
1529 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
1530 | rpec, cpec); | |
24a5bb7b | 1531 | return -EBADMSG; |
1da177e4 | 1532 | } |
438d6c2c | 1533 | return 0; |
1da177e4 LT |
1534 | } |
1535 | ||
a1cdedac DB |
1536 | /** |
1537 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
1538 | * @client: Handle to slave device | |
1539 | * | |
1540 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
1541 | * else the byte received from the device. | |
1542 | */ | |
1da177e4 LT |
1543 | s32 i2c_smbus_read_byte(struct i2c_client *client) |
1544 | { | |
1545 | union i2c_smbus_data data; | |
24a5bb7b DB |
1546 | int status; |
1547 | ||
1548 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1549 | I2C_SMBUS_READ, 0, | |
1550 | I2C_SMBUS_BYTE, &data); | |
1551 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1552 | } |
c0564606 | 1553 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 1554 | |
a1cdedac DB |
1555 | /** |
1556 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
1557 | * @client: Handle to slave device | |
1558 | * @value: Byte to be sent | |
1559 | * | |
1560 | * This executes the SMBus "send byte" protocol, returning negative errno | |
1561 | * else zero on success. | |
1562 | */ | |
1da177e4 LT |
1563 | s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) |
1564 | { | |
1da177e4 | 1565 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
421ef47b | 1566 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 1567 | } |
c0564606 | 1568 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 1569 | |
a1cdedac DB |
1570 | /** |
1571 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
1572 | * @client: Handle to slave device | |
1573 | * @command: Byte interpreted by slave | |
1574 | * | |
1575 | * This executes the SMBus "read byte" protocol, returning negative errno | |
1576 | * else a data byte received from the device. | |
1577 | */ | |
1da177e4 LT |
1578 | s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) |
1579 | { | |
1580 | union i2c_smbus_data data; | |
24a5bb7b DB |
1581 | int status; |
1582 | ||
1583 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1584 | I2C_SMBUS_READ, command, | |
1585 | I2C_SMBUS_BYTE_DATA, &data); | |
1586 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1587 | } |
c0564606 | 1588 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 1589 | |
a1cdedac DB |
1590 | /** |
1591 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
1592 | * @client: Handle to slave device | |
1593 | * @command: Byte interpreted by slave | |
1594 | * @value: Byte being written | |
1595 | * | |
1596 | * This executes the SMBus "write byte" protocol, returning negative errno | |
1597 | * else zero on success. | |
1598 | */ | |
1da177e4 LT |
1599 | s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) |
1600 | { | |
1601 | union i2c_smbus_data data; | |
1602 | data.byte = value; | |
1603 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1604 | I2C_SMBUS_WRITE,command, | |
1605 | I2C_SMBUS_BYTE_DATA,&data); | |
1606 | } | |
c0564606 | 1607 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 1608 | |
a1cdedac DB |
1609 | /** |
1610 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
1611 | * @client: Handle to slave device | |
1612 | * @command: Byte interpreted by slave | |
1613 | * | |
1614 | * This executes the SMBus "read word" protocol, returning negative errno | |
1615 | * else a 16-bit unsigned "word" received from the device. | |
1616 | */ | |
1da177e4 LT |
1617 | s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) |
1618 | { | |
1619 | union i2c_smbus_data data; | |
24a5bb7b DB |
1620 | int status; |
1621 | ||
1622 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1623 | I2C_SMBUS_READ, command, | |
1624 | I2C_SMBUS_WORD_DATA, &data); | |
1625 | return (status < 0) ? status : data.word; | |
1da177e4 | 1626 | } |
c0564606 | 1627 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 1628 | |
a1cdedac DB |
1629 | /** |
1630 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
1631 | * @client: Handle to slave device | |
1632 | * @command: Byte interpreted by slave | |
1633 | * @value: 16-bit "word" being written | |
1634 | * | |
1635 | * This executes the SMBus "write word" protocol, returning negative errno | |
1636 | * else zero on success. | |
1637 | */ | |
1da177e4 LT |
1638 | s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) |
1639 | { | |
1640 | union i2c_smbus_data data; | |
1641 | data.word = value; | |
1642 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1643 | I2C_SMBUS_WRITE,command, | |
1644 | I2C_SMBUS_WORD_DATA,&data); | |
1645 | } | |
c0564606 | 1646 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 1647 | |
596c88f4 PM |
1648 | /** |
1649 | * i2c_smbus_process_call - SMBus "process call" protocol | |
1650 | * @client: Handle to slave device | |
1651 | * @command: Byte interpreted by slave | |
1652 | * @value: 16-bit "word" being written | |
1653 | * | |
1654 | * This executes the SMBus "process call" protocol, returning negative errno | |
1655 | * else a 16-bit unsigned "word" received from the device. | |
1656 | */ | |
1657 | s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value) | |
1658 | { | |
1659 | union i2c_smbus_data data; | |
1660 | int status; | |
1661 | data.word = value; | |
1662 | ||
1663 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1664 | I2C_SMBUS_WRITE, command, | |
1665 | I2C_SMBUS_PROC_CALL, &data); | |
1666 | return (status < 0) ? status : data.word; | |
1667 | } | |
1668 | EXPORT_SYMBOL(i2c_smbus_process_call); | |
1669 | ||
a64ec07d | 1670 | /** |
a1cdedac | 1671 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 1672 | * @client: Handle to slave device |
a1cdedac | 1673 | * @command: Byte interpreted by slave |
a64ec07d DB |
1674 | * @values: Byte array into which data will be read; big enough to hold |
1675 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
1676 | * | |
a1cdedac DB |
1677 | * This executes the SMBus "block read" protocol, returning negative errno |
1678 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
1679 | * |
1680 | * Note that using this function requires that the client's adapter support | |
1681 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
1682 | * support this; its emulation through I2C messaging relies on a specific | |
1683 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
1684 | */ | |
b86a1bc8 JD |
1685 | s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, |
1686 | u8 *values) | |
1687 | { | |
1688 | union i2c_smbus_data data; | |
24a5bb7b | 1689 | int status; |
b86a1bc8 | 1690 | |
24a5bb7b DB |
1691 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1692 | I2C_SMBUS_READ, command, | |
1693 | I2C_SMBUS_BLOCK_DATA, &data); | |
1694 | if (status) | |
1695 | return status; | |
b86a1bc8 JD |
1696 | |
1697 | memcpy(values, &data.block[1], data.block[0]); | |
1698 | return data.block[0]; | |
1699 | } | |
1700 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
1701 | ||
a1cdedac DB |
1702 | /** |
1703 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
1704 | * @client: Handle to slave device | |
1705 | * @command: Byte interpreted by slave | |
1706 | * @length: Size of data block; SMBus allows at most 32 bytes | |
1707 | * @values: Byte array which will be written. | |
1708 | * | |
1709 | * This executes the SMBus "block write" protocol, returning negative errno | |
1710 | * else zero on success. | |
1711 | */ | |
1da177e4 | 1712 | s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1713 | u8 length, const u8 *values) |
1da177e4 LT |
1714 | { |
1715 | union i2c_smbus_data data; | |
7656032b | 1716 | |
1da177e4 LT |
1717 | if (length > I2C_SMBUS_BLOCK_MAX) |
1718 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 1719 | data.block[0] = length; |
7656032b | 1720 | memcpy(&data.block[1], values, length); |
1da177e4 LT |
1721 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
1722 | I2C_SMBUS_WRITE,command, | |
1723 | I2C_SMBUS_BLOCK_DATA,&data); | |
1724 | } | |
c0564606 | 1725 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
1726 | |
1727 | /* Returns the number of read bytes */ | |
4b2643d7 JD |
1728 | s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, |
1729 | u8 length, u8 *values) | |
1da177e4 LT |
1730 | { |
1731 | union i2c_smbus_data data; | |
24a5bb7b | 1732 | int status; |
7656032b | 1733 | |
4b2643d7 JD |
1734 | if (length > I2C_SMBUS_BLOCK_MAX) |
1735 | length = I2C_SMBUS_BLOCK_MAX; | |
1736 | data.block[0] = length; | |
24a5bb7b DB |
1737 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1738 | I2C_SMBUS_READ, command, | |
1739 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1740 | if (status < 0) | |
1741 | return status; | |
7656032b JD |
1742 | |
1743 | memcpy(values, &data.block[1], data.block[0]); | |
1744 | return data.block[0]; | |
1da177e4 | 1745 | } |
c0564606 | 1746 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 1747 | |
21bbd691 | 1748 | s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1749 | u8 length, const u8 *values) |
21bbd691 JD |
1750 | { |
1751 | union i2c_smbus_data data; | |
1752 | ||
1753 | if (length > I2C_SMBUS_BLOCK_MAX) | |
1754 | length = I2C_SMBUS_BLOCK_MAX; | |
1755 | data.block[0] = length; | |
1756 | memcpy(data.block + 1, values, length); | |
1757 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1758 | I2C_SMBUS_WRITE, command, | |
1759 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1760 | } | |
c0564606 | 1761 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 1762 | |
438d6c2c | 1763 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 1764 | No checking of parameters is done! */ |
438d6c2c | 1765 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, |
1da177e4 | 1766 | unsigned short flags, |
438d6c2c | 1767 | char read_write, u8 command, int size, |
1da177e4 LT |
1768 | union i2c_smbus_data * data) |
1769 | { | |
1770 | /* So we need to generate a series of msgs. In the case of writing, we | |
1771 | need to use only one message; when reading, we need two. We initialize | |
1772 | most things with sane defaults, to keep the code below somewhat | |
1773 | simpler. */ | |
5c50d188 HI |
1774 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
1775 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
1da177e4 | 1776 | int num = read_write == I2C_SMBUS_READ?2:1; |
438d6c2c | 1777 | struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 }, |
1da177e4 LT |
1778 | { addr, flags | I2C_M_RD, 0, msgbuf1 } |
1779 | }; | |
1780 | int i; | |
421ef47b | 1781 | u8 partial_pec = 0; |
24a5bb7b | 1782 | int status; |
1da177e4 LT |
1783 | |
1784 | msgbuf0[0] = command; | |
1785 | switch(size) { | |
1786 | case I2C_SMBUS_QUICK: | |
1787 | msg[0].len = 0; | |
1788 | /* Special case: The read/write field is used as data */ | |
f29d2e02 RK |
1789 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
1790 | I2C_M_RD : 0); | |
1da177e4 LT |
1791 | num = 1; |
1792 | break; | |
1793 | case I2C_SMBUS_BYTE: | |
1794 | if (read_write == I2C_SMBUS_READ) { | |
1795 | /* Special case: only a read! */ | |
1796 | msg[0].flags = I2C_M_RD | flags; | |
1797 | num = 1; | |
1798 | } | |
1799 | break; | |
1800 | case I2C_SMBUS_BYTE_DATA: | |
1801 | if (read_write == I2C_SMBUS_READ) | |
1802 | msg[1].len = 1; | |
1803 | else { | |
1804 | msg[0].len = 2; | |
1805 | msgbuf0[1] = data->byte; | |
1806 | } | |
1807 | break; | |
1808 | case I2C_SMBUS_WORD_DATA: | |
1809 | if (read_write == I2C_SMBUS_READ) | |
1810 | msg[1].len = 2; | |
1811 | else { | |
1812 | msg[0].len=3; | |
1813 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1814 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1815 | } |
1816 | break; | |
1817 | case I2C_SMBUS_PROC_CALL: | |
1818 | num = 2; /* Special case */ | |
1819 | read_write = I2C_SMBUS_READ; | |
1820 | msg[0].len = 3; | |
1821 | msg[1].len = 2; | |
1822 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1823 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1824 | break; |
1825 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 1826 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
1827 | msg[1].flags |= I2C_M_RECV_LEN; |
1828 | msg[1].len = 1; /* block length will be added by | |
1829 | the underlying bus driver */ | |
1da177e4 LT |
1830 | } else { |
1831 | msg[0].len = data->block[0] + 2; | |
1832 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
1833 | dev_err(&adapter->dev, |
1834 | "Invalid block write size %d\n", | |
1835 | data->block[0]); | |
1836 | return -EINVAL; | |
1da177e4 | 1837 | } |
5c50d188 | 1838 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
1839 | msgbuf0[i] = data->block[i-1]; |
1840 | } | |
1841 | break; | |
1842 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
1843 | num = 2; /* Another special case */ |
1844 | read_write = I2C_SMBUS_READ; | |
1845 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
1846 | dev_err(&adapter->dev, |
1847 | "Invalid block write size %d\n", | |
209d27c3 | 1848 | data->block[0]); |
24a5bb7b | 1849 | return -EINVAL; |
209d27c3 JD |
1850 | } |
1851 | msg[0].len = data->block[0] + 2; | |
1852 | for (i = 1; i < msg[0].len; i++) | |
1853 | msgbuf0[i] = data->block[i-1]; | |
1854 | msg[1].flags |= I2C_M_RECV_LEN; | |
1855 | msg[1].len = 1; /* block length will be added by | |
1856 | the underlying bus driver */ | |
1857 | break; | |
1da177e4 LT |
1858 | case I2C_SMBUS_I2C_BLOCK_DATA: |
1859 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 1860 | msg[1].len = data->block[0]; |
1da177e4 LT |
1861 | } else { |
1862 | msg[0].len = data->block[0] + 1; | |
30dac746 | 1863 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
1864 | dev_err(&adapter->dev, |
1865 | "Invalid block write size %d\n", | |
1866 | data->block[0]); | |
1867 | return -EINVAL; | |
1da177e4 LT |
1868 | } |
1869 | for (i = 1; i <= data->block[0]; i++) | |
1870 | msgbuf0[i] = data->block[i]; | |
1871 | } | |
1872 | break; | |
1873 | default: | |
24a5bb7b DB |
1874 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
1875 | return -EOPNOTSUPP; | |
1da177e4 LT |
1876 | } |
1877 | ||
421ef47b JD |
1878 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
1879 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
1880 | if (i) { | |
1881 | /* Compute PEC if first message is a write */ | |
1882 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 1883 | if (num == 1) /* Write only */ |
421ef47b JD |
1884 | i2c_smbus_add_pec(&msg[0]); |
1885 | else /* Write followed by read */ | |
1886 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
1887 | } | |
1888 | /* Ask for PEC if last message is a read */ | |
1889 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 1890 | msg[num-1].len++; |
421ef47b JD |
1891 | } |
1892 | ||
24a5bb7b DB |
1893 | status = i2c_transfer(adapter, msg, num); |
1894 | if (status < 0) | |
1895 | return status; | |
1da177e4 | 1896 | |
421ef47b JD |
1897 | /* Check PEC if last message is a read */ |
1898 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
1899 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
1900 | if (status < 0) | |
1901 | return status; | |
421ef47b JD |
1902 | } |
1903 | ||
1da177e4 LT |
1904 | if (read_write == I2C_SMBUS_READ) |
1905 | switch(size) { | |
1906 | case I2C_SMBUS_BYTE: | |
1907 | data->byte = msgbuf0[0]; | |
1908 | break; | |
1909 | case I2C_SMBUS_BYTE_DATA: | |
1910 | data->byte = msgbuf1[0]; | |
1911 | break; | |
438d6c2c | 1912 | case I2C_SMBUS_WORD_DATA: |
1da177e4 LT |
1913 | case I2C_SMBUS_PROC_CALL: |
1914 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
1915 | break; | |
1916 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
4b2643d7 | 1917 | for (i = 0; i < data->block[0]; i++) |
1da177e4 LT |
1918 | data->block[i+1] = msgbuf1[i]; |
1919 | break; | |
209d27c3 JD |
1920 | case I2C_SMBUS_BLOCK_DATA: |
1921 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
1922 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
1923 | data->block[i] = msgbuf1[i]; | |
1924 | break; | |
1da177e4 LT |
1925 | } |
1926 | return 0; | |
1927 | } | |
1928 | ||
a1cdedac DB |
1929 | /** |
1930 | * i2c_smbus_xfer - execute SMBus protocol operations | |
1931 | * @adapter: Handle to I2C bus | |
1932 | * @addr: Address of SMBus slave on that bus | |
1933 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
1934 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
1935 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
1936 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
1937 | * @data: Data to be read or written | |
1938 | * | |
1939 | * This executes an SMBus protocol operation, and returns a negative | |
1940 | * errno code else zero on success. | |
1941 | */ | |
09b8ce0a | 1942 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
a1cdedac | 1943 | char read_write, u8 command, int protocol, |
09b8ce0a | 1944 | union i2c_smbus_data *data) |
1da177e4 | 1945 | { |
66b650f0 CW |
1946 | unsigned long orig_jiffies; |
1947 | int try; | |
1da177e4 | 1948 | s32 res; |
1da177e4 LT |
1949 | |
1950 | flags &= I2C_M_TEN | I2C_CLIENT_PEC; | |
1da177e4 LT |
1951 | |
1952 | if (adapter->algo->smbus_xfer) { | |
194684e5 | 1953 | rt_mutex_lock(&adapter->bus_lock); |
66b650f0 CW |
1954 | |
1955 | /* Retry automatically on arbitration loss */ | |
1956 | orig_jiffies = jiffies; | |
1957 | for (res = 0, try = 0; try <= adapter->retries; try++) { | |
1958 | res = adapter->algo->smbus_xfer(adapter, addr, flags, | |
1959 | read_write, command, | |
1960 | protocol, data); | |
1961 | if (res != -EAGAIN) | |
1962 | break; | |
1963 | if (time_after(jiffies, | |
1964 | orig_jiffies + adapter->timeout)) | |
1965 | break; | |
1966 | } | |
194684e5 | 1967 | rt_mutex_unlock(&adapter->bus_lock); |
1da177e4 LT |
1968 | } else |
1969 | res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write, | |
a1cdedac | 1970 | command, protocol, data); |
1da177e4 | 1971 | |
1da177e4 LT |
1972 | return res; |
1973 | } | |
1da177e4 | 1974 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
1975 | |
1976 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
1977 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
1978 | MODULE_LICENSE("GPL"); |