Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* i2c-core.c - a device driver for the iic-bus interface */ |
2 | /* ------------------------------------------------------------------------- */ | |
3 | /* Copyright (C) 1995-99 Simon G. Vogl | |
4 | ||
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
7 | the Free Software Foundation; either version 2 of the License, or | |
8 | (at your option) any later version. | |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
16 | along with this program; if not, write to the Free Software | |
17 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
18 | /* ------------------------------------------------------------------------- */ | |
19 | ||
96de0e25 | 20 | /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>. |
1da177e4 | 21 | All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl> |
421ef47b JD |
22 | SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and |
23 | Jean Delvare <khali@linux-fr.org> */ | |
1da177e4 | 24 | |
1da177e4 LT |
25 | #include <linux/module.h> |
26 | #include <linux/kernel.h> | |
27 | #include <linux/errno.h> | |
28 | #include <linux/slab.h> | |
29 | #include <linux/i2c.h> | |
30 | #include <linux/init.h> | |
31 | #include <linux/idr.h> | |
b3585e4f | 32 | #include <linux/mutex.h> |
b8d6f45b | 33 | #include <linux/completion.h> |
cea443a8 MR |
34 | #include <linux/hardirq.h> |
35 | #include <linux/irqflags.h> | |
f18c41da | 36 | #include <linux/rwsem.h> |
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; |
4735c98f | 50 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
f37dd80a DB |
51 | |
52 | /* ------------------------------------------------------------------------- */ | |
53 | ||
d2653e92 JD |
54 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
55 | const struct i2c_client *client) | |
56 | { | |
57 | while (id->name[0]) { | |
58 | if (strcmp(client->name, id->name) == 0) | |
59 | return id; | |
60 | id++; | |
61 | } | |
62 | return NULL; | |
63 | } | |
64 | ||
1da177e4 LT |
65 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
66 | { | |
51298d12 JD |
67 | struct i2c_client *client = i2c_verify_client(dev); |
68 | struct i2c_driver *driver; | |
69 | ||
70 | if (!client) | |
71 | return 0; | |
7b4fbc50 | 72 | |
51298d12 | 73 | driver = to_i2c_driver(drv); |
d2653e92 JD |
74 | /* match on an id table if there is one */ |
75 | if (driver->id_table) | |
76 | return i2c_match_id(driver->id_table, client) != NULL; | |
77 | ||
eb8a7908 | 78 | return 0; |
1da177e4 LT |
79 | } |
80 | ||
7b4fbc50 DB |
81 | #ifdef CONFIG_HOTPLUG |
82 | ||
83 | /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ | |
7eff2e7a | 84 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 DB |
85 | { |
86 | struct i2c_client *client = to_i2c_client(dev); | |
7b4fbc50 | 87 | |
eb8a7908 JD |
88 | if (add_uevent_var(env, "MODALIAS=%s%s", |
89 | I2C_MODULE_PREFIX, client->name)) | |
90 | return -ENOMEM; | |
7b4fbc50 DB |
91 | dev_dbg(dev, "uevent\n"); |
92 | return 0; | |
93 | } | |
94 | ||
95 | #else | |
96 | #define i2c_device_uevent NULL | |
97 | #endif /* CONFIG_HOTPLUG */ | |
98 | ||
f37dd80a | 99 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 100 | { |
51298d12 JD |
101 | struct i2c_client *client = i2c_verify_client(dev); |
102 | struct i2c_driver *driver; | |
50c3304a | 103 | int status; |
7b4fbc50 | 104 | |
51298d12 JD |
105 | if (!client) |
106 | return 0; | |
107 | ||
108 | driver = to_i2c_driver(dev->driver); | |
e0457442 | 109 | if (!driver->probe || !driver->id_table) |
7b4fbc50 DB |
110 | return -ENODEV; |
111 | client->driver = driver; | |
ee35425c MP |
112 | if (!device_can_wakeup(&client->dev)) |
113 | device_init_wakeup(&client->dev, | |
114 | client->flags & I2C_CLIENT_WAKE); | |
7b4fbc50 | 115 | dev_dbg(dev, "probe\n"); |
d2653e92 | 116 | |
e0457442 | 117 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
e4a7b9b0 | 118 | if (status) { |
50c3304a | 119 | client->driver = NULL; |
e4a7b9b0 WS |
120 | i2c_set_clientdata(client, NULL); |
121 | } | |
50c3304a | 122 | return status; |
f37dd80a | 123 | } |
1da177e4 | 124 | |
f37dd80a DB |
125 | static int i2c_device_remove(struct device *dev) |
126 | { | |
51298d12 | 127 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 DB |
128 | struct i2c_driver *driver; |
129 | int status; | |
130 | ||
51298d12 | 131 | if (!client || !dev->driver) |
a1d9e6e4 DB |
132 | return 0; |
133 | ||
134 | driver = to_i2c_driver(dev->driver); | |
135 | if (driver->remove) { | |
136 | dev_dbg(dev, "remove\n"); | |
137 | status = driver->remove(client); | |
138 | } else { | |
139 | dev->driver = NULL; | |
140 | status = 0; | |
141 | } | |
e4a7b9b0 | 142 | if (status == 0) { |
a1d9e6e4 | 143 | client->driver = NULL; |
e4a7b9b0 WS |
144 | i2c_set_clientdata(client, NULL); |
145 | } | |
a1d9e6e4 | 146 | return status; |
1da177e4 LT |
147 | } |
148 | ||
f37dd80a | 149 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 150 | { |
51298d12 | 151 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
152 | struct i2c_driver *driver; |
153 | ||
51298d12 | 154 | if (!client || !dev->driver) |
f37dd80a DB |
155 | return; |
156 | driver = to_i2c_driver(dev->driver); | |
157 | if (driver->shutdown) | |
51298d12 | 158 | driver->shutdown(client); |
1da177e4 LT |
159 | } |
160 | ||
2f60ba70 RW |
161 | #ifdef CONFIG_PM_SLEEP |
162 | static int i2c_legacy_suspend(struct device *dev, pm_message_t mesg) | |
54067ee2 | 163 | { |
2f60ba70 RW |
164 | struct i2c_client *client = i2c_verify_client(dev); |
165 | struct i2c_driver *driver; | |
54067ee2 | 166 | |
2f60ba70 | 167 | if (!client || !dev->driver) |
54067ee2 | 168 | return 0; |
2f60ba70 RW |
169 | driver = to_i2c_driver(dev->driver); |
170 | if (!driver->suspend) | |
54067ee2 | 171 | return 0; |
2f60ba70 | 172 | return driver->suspend(client, mesg); |
54067ee2 | 173 | } |
174 | ||
2f60ba70 | 175 | static int i2c_legacy_resume(struct device *dev) |
54067ee2 | 176 | { |
2f60ba70 RW |
177 | struct i2c_client *client = i2c_verify_client(dev); |
178 | struct i2c_driver *driver; | |
54067ee2 | 179 | |
2f60ba70 | 180 | if (!client || !dev->driver) |
54067ee2 | 181 | return 0; |
2f60ba70 RW |
182 | driver = to_i2c_driver(dev->driver); |
183 | if (!driver->resume) | |
54067ee2 | 184 | return 0; |
2f60ba70 | 185 | return driver->resume(client); |
54067ee2 | 186 | } |
54067ee2 | 187 | |
2f60ba70 | 188 | static int i2c_device_pm_suspend(struct device *dev) |
6de468ae | 189 | { |
2f60ba70 | 190 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 191 | |
2f60ba70 | 192 | if (pm_runtime_suspended(dev)) |
6de468ae | 193 | return 0; |
6de468ae | 194 | |
2f60ba70 RW |
195 | if (pm) |
196 | return pm->suspend ? pm->suspend(dev) : 0; | |
6de468ae | 197 | |
2f60ba70 | 198 | return i2c_legacy_suspend(dev, PMSG_SUSPEND); |
6de468ae MB |
199 | } |
200 | ||
2f60ba70 | 201 | static int i2c_device_pm_resume(struct device *dev) |
6de468ae | 202 | { |
2f60ba70 | 203 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae MB |
204 | int ret; |
205 | ||
2f60ba70 RW |
206 | if (pm) |
207 | ret = pm->resume ? pm->resume(dev) : 0; | |
208 | else | |
209 | ret = i2c_legacy_resume(dev); | |
210 | ||
211 | if (!ret) { | |
212 | pm_runtime_disable(dev); | |
213 | pm_runtime_set_active(dev); | |
214 | pm_runtime_enable(dev); | |
6de468ae MB |
215 | } |
216 | ||
2f60ba70 | 217 | return ret; |
6de468ae | 218 | } |
6de468ae | 219 | |
2f60ba70 | 220 | static int i2c_device_pm_freeze(struct device *dev) |
1da177e4 | 221 | { |
2f60ba70 | 222 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 223 | |
2f60ba70 | 224 | if (pm_runtime_suspended(dev)) |
f37dd80a | 225 | return 0; |
2f60ba70 RW |
226 | |
227 | if (pm) | |
228 | return pm->freeze ? pm->freeze(dev) : 0; | |
229 | ||
230 | return i2c_legacy_suspend(dev, PMSG_FREEZE); | |
1da177e4 LT |
231 | } |
232 | ||
2f60ba70 | 233 | static int i2c_device_pm_thaw(struct device *dev) |
1da177e4 | 234 | { |
2f60ba70 | 235 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 236 | |
2f60ba70 | 237 | if (pm_runtime_suspended(dev)) |
f37dd80a | 238 | return 0; |
2f60ba70 RW |
239 | |
240 | if (pm) | |
241 | return pm->thaw ? pm->thaw(dev) : 0; | |
242 | ||
243 | return i2c_legacy_resume(dev); | |
244 | } | |
245 | ||
246 | static int i2c_device_pm_poweroff(struct device *dev) | |
247 | { | |
248 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
249 | ||
250 | if (pm_runtime_suspended(dev)) | |
f37dd80a | 251 | return 0; |
2f60ba70 RW |
252 | |
253 | if (pm) | |
254 | return pm->poweroff ? pm->poweroff(dev) : 0; | |
255 | ||
256 | return i2c_legacy_suspend(dev, PMSG_HIBERNATE); | |
257 | } | |
258 | ||
259 | static int i2c_device_pm_restore(struct device *dev) | |
260 | { | |
261 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
262 | int ret; | |
263 | ||
264 | if (pm) | |
265 | ret = pm->restore ? pm->restore(dev) : 0; | |
266 | else | |
267 | ret = i2c_legacy_resume(dev); | |
268 | ||
269 | if (!ret) { | |
270 | pm_runtime_disable(dev); | |
271 | pm_runtime_set_active(dev); | |
272 | pm_runtime_enable(dev); | |
273 | } | |
274 | ||
275 | return ret; | |
1da177e4 | 276 | } |
2f60ba70 RW |
277 | #else /* !CONFIG_PM_SLEEP */ |
278 | #define i2c_device_pm_suspend NULL | |
279 | #define i2c_device_pm_resume NULL | |
280 | #define i2c_device_pm_freeze NULL | |
281 | #define i2c_device_pm_thaw NULL | |
282 | #define i2c_device_pm_poweroff NULL | |
283 | #define i2c_device_pm_restore NULL | |
284 | #endif /* !CONFIG_PM_SLEEP */ | |
1da177e4 | 285 | |
9c1600ed DB |
286 | static void i2c_client_dev_release(struct device *dev) |
287 | { | |
288 | kfree(to_i2c_client(dev)); | |
289 | } | |
290 | ||
09b8ce0a | 291 | static ssize_t |
4f8cf824 | 292 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 293 | { |
4f8cf824 JD |
294 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
295 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 DB |
296 | } |
297 | ||
09b8ce0a ZX |
298 | static ssize_t |
299 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
300 | { |
301 | struct i2c_client *client = to_i2c_client(dev); | |
eb8a7908 | 302 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
303 | } |
304 | ||
4f8cf824 | 305 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
51298d12 JD |
306 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
307 | ||
308 | static struct attribute *i2c_dev_attrs[] = { | |
309 | &dev_attr_name.attr, | |
7b4fbc50 | 310 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
311 | &dev_attr_modalias.attr, |
312 | NULL | |
313 | }; | |
314 | ||
315 | static struct attribute_group i2c_dev_attr_group = { | |
316 | .attrs = i2c_dev_attrs, | |
317 | }; | |
318 | ||
319 | static const struct attribute_group *i2c_dev_attr_groups[] = { | |
320 | &i2c_dev_attr_group, | |
321 | NULL | |
7b4fbc50 DB |
322 | }; |
323 | ||
0b2c3688 | 324 | static const struct dev_pm_ops i2c_device_pm_ops = { |
54067ee2 | 325 | .suspend = i2c_device_pm_suspend, |
326 | .resume = i2c_device_pm_resume, | |
2f60ba70 RW |
327 | .freeze = i2c_device_pm_freeze, |
328 | .thaw = i2c_device_pm_thaw, | |
329 | .poweroff = i2c_device_pm_poweroff, | |
330 | .restore = i2c_device_pm_restore, | |
331 | SET_RUNTIME_PM_OPS( | |
332 | pm_generic_runtime_suspend, | |
333 | pm_generic_runtime_resume, | |
334 | pm_generic_runtime_idle | |
335 | ) | |
54067ee2 | 336 | }; |
337 | ||
e9ca9eb9 | 338 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
339 | .name = "i2c", |
340 | .match = i2c_device_match, | |
341 | .probe = i2c_device_probe, | |
342 | .remove = i2c_device_remove, | |
343 | .shutdown = i2c_device_shutdown, | |
54067ee2 | 344 | .pm = &i2c_device_pm_ops, |
b864c7d5 | 345 | }; |
e9ca9eb9 | 346 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 347 | |
51298d12 JD |
348 | static struct device_type i2c_client_type = { |
349 | .groups = i2c_dev_attr_groups, | |
350 | .uevent = i2c_device_uevent, | |
351 | .release = i2c_client_dev_release, | |
352 | }; | |
353 | ||
9b766b81 DB |
354 | |
355 | /** | |
356 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
357 | * @dev: device, probably from some driver model iterator | |
358 | * | |
359 | * When traversing the driver model tree, perhaps using driver model | |
360 | * iterators like @device_for_each_child(), you can't assume very much | |
361 | * about the nodes you find. Use this function to avoid oopses caused | |
362 | * by wrongly treating some non-I2C device as an i2c_client. | |
363 | */ | |
364 | struct i2c_client *i2c_verify_client(struct device *dev) | |
365 | { | |
51298d12 | 366 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
367 | ? to_i2c_client(dev) |
368 | : NULL; | |
369 | } | |
370 | EXPORT_SYMBOL(i2c_verify_client); | |
371 | ||
372 | ||
3a89db5f JD |
373 | /* This is a permissive address validity check, I2C address map constraints |
374 | * are purposedly not enforced, except for the general call address. */ | |
375 | static int i2c_check_client_addr_validity(const struct i2c_client *client) | |
376 | { | |
377 | if (client->flags & I2C_CLIENT_TEN) { | |
378 | /* 10-bit address, all values are valid */ | |
379 | if (client->addr > 0x3ff) | |
380 | return -EINVAL; | |
381 | } else { | |
382 | /* 7-bit address, reject the general call address */ | |
383 | if (client->addr == 0x00 || client->addr > 0x7f) | |
384 | return -EINVAL; | |
385 | } | |
386 | return 0; | |
387 | } | |
388 | ||
656b8761 JD |
389 | /* And this is a strict address validity check, used when probing. If a |
390 | * device uses a reserved address, then it shouldn't be probed. 7-bit | |
391 | * addressing is assumed, 10-bit address devices are rare and should be | |
392 | * explicitly enumerated. */ | |
393 | static int i2c_check_addr_validity(unsigned short addr) | |
394 | { | |
395 | /* | |
396 | * Reserved addresses per I2C specification: | |
397 | * 0x00 General call address / START byte | |
398 | * 0x01 CBUS address | |
399 | * 0x02 Reserved for different bus format | |
400 | * 0x03 Reserved for future purposes | |
401 | * 0x04-0x07 Hs-mode master code | |
402 | * 0x78-0x7b 10-bit slave addressing | |
403 | * 0x7c-0x7f Reserved for future purposes | |
404 | */ | |
405 | if (addr < 0x08 || addr > 0x77) | |
406 | return -EINVAL; | |
407 | return 0; | |
408 | } | |
409 | ||
3b5f794b JD |
410 | static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
411 | { | |
412 | struct i2c_client *client = i2c_verify_client(dev); | |
413 | int addr = *(int *)addrp; | |
414 | ||
415 | if (client && client->addr == addr) | |
416 | return -EBUSY; | |
417 | return 0; | |
418 | } | |
419 | ||
420 | static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) | |
421 | { | |
422 | return device_for_each_child(&adapter->dev, &addr, | |
423 | __i2c_check_addr_busy); | |
424 | } | |
425 | ||
9c1600ed | 426 | /** |
f8a227e8 | 427 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
428 | * @adap: the adapter managing the device |
429 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 430 | * Context: can sleep |
9c1600ed | 431 | * |
f8a227e8 JD |
432 | * Create an i2c device. Binding is handled through driver model |
433 | * probe()/remove() methods. A driver may be bound to this device when we | |
434 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
435 | * load the driver module). This call is not appropriate for use by mainboard | |
436 | * initialization logic, which usually runs during an arch_initcall() long | |
437 | * before any i2c_adapter could exist. | |
9c1600ed DB |
438 | * |
439 | * This returns the new i2c client, which may be saved for later use with | |
440 | * i2c_unregister_device(); or NULL to indicate an error. | |
441 | */ | |
442 | struct i2c_client * | |
443 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
444 | { | |
445 | struct i2c_client *client; | |
446 | int status; | |
447 | ||
448 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
449 | if (!client) | |
450 | return NULL; | |
451 | ||
452 | client->adapter = adap; | |
453 | ||
454 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 455 | |
11f1f2af AV |
456 | if (info->archdata) |
457 | client->dev.archdata = *info->archdata; | |
458 | ||
ee35425c | 459 | client->flags = info->flags; |
9c1600ed DB |
460 | client->addr = info->addr; |
461 | client->irq = info->irq; | |
462 | ||
9c1600ed DB |
463 | strlcpy(client->name, info->type, sizeof(client->name)); |
464 | ||
3a89db5f JD |
465 | /* Check for address validity */ |
466 | status = i2c_check_client_addr_validity(client); | |
467 | if (status) { | |
468 | dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", | |
469 | client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); | |
470 | goto out_err_silent; | |
471 | } | |
472 | ||
f8a227e8 | 473 | /* Check for address business */ |
3b5f794b | 474 | status = i2c_check_addr_busy(adap, client->addr); |
f8a227e8 JD |
475 | if (status) |
476 | goto out_err; | |
477 | ||
478 | client->dev.parent = &client->adapter->dev; | |
479 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 480 | client->dev.type = &i2c_client_type; |
d12d42f7 GL |
481 | #ifdef CONFIG_OF |
482 | client->dev.of_node = info->of_node; | |
483 | #endif | |
f8a227e8 JD |
484 | |
485 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), | |
486 | client->addr); | |
487 | status = device_register(&client->dev); | |
488 | if (status) | |
489 | goto out_err; | |
490 | ||
f8a227e8 JD |
491 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
492 | client->name, dev_name(&client->dev)); | |
493 | ||
9c1600ed | 494 | return client; |
f8a227e8 JD |
495 | |
496 | out_err: | |
497 | dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " | |
498 | "(%d)\n", client->name, client->addr, status); | |
3a89db5f | 499 | out_err_silent: |
f8a227e8 JD |
500 | kfree(client); |
501 | return NULL; | |
9c1600ed DB |
502 | } |
503 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
504 | ||
505 | ||
506 | /** | |
507 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
508 | * @client: value returned from i2c_new_device() | |
d64f73be | 509 | * Context: can sleep |
9c1600ed DB |
510 | */ |
511 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 512 | { |
a1d9e6e4 DB |
513 | device_unregister(&client->dev); |
514 | } | |
9c1600ed | 515 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
516 | |
517 | ||
60b129d7 JD |
518 | static const struct i2c_device_id dummy_id[] = { |
519 | { "dummy", 0 }, | |
520 | { }, | |
521 | }; | |
522 | ||
d2653e92 JD |
523 | static int dummy_probe(struct i2c_client *client, |
524 | const struct i2c_device_id *id) | |
525 | { | |
526 | return 0; | |
527 | } | |
528 | ||
529 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
530 | { |
531 | return 0; | |
532 | } | |
533 | ||
534 | static struct i2c_driver dummy_driver = { | |
535 | .driver.name = "dummy", | |
d2653e92 JD |
536 | .probe = dummy_probe, |
537 | .remove = dummy_remove, | |
60b129d7 | 538 | .id_table = dummy_id, |
e9f1373b DB |
539 | }; |
540 | ||
541 | /** | |
542 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
543 | * @adapter: the adapter managing the device | |
544 | * @address: seven bit address to be used | |
e9f1373b DB |
545 | * Context: can sleep |
546 | * | |
547 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
548 | * with devices that consume multiple addresses. Examples of such chips | |
549 | * include various EEPROMS (like 24c04 and 24c08 models). | |
550 | * | |
551 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
552 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
553 | * And second, this prevents the specified address from being bound to a | |
554 | * different driver. | |
555 | * | |
556 | * This returns the new i2c client, which should be saved for later use with | |
557 | * i2c_unregister_device(); or NULL to indicate an error. | |
558 | */ | |
09b8ce0a | 559 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
560 | { |
561 | struct i2c_board_info info = { | |
60b129d7 | 562 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
563 | }; |
564 | ||
e9f1373b DB |
565 | return i2c_new_device(adapter, &info); |
566 | } | |
567 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
568 | ||
f37dd80a DB |
569 | /* ------------------------------------------------------------------------- */ |
570 | ||
16ffadfc DB |
571 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
572 | ||
83eaaed0 | 573 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 574 | { |
ef2c8321 | 575 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
576 | complete(&adap->dev_released); |
577 | } | |
578 | ||
99cd8e25 JD |
579 | /* |
580 | * Let users instantiate I2C devices through sysfs. This can be used when | |
581 | * platform initialization code doesn't contain the proper data for | |
582 | * whatever reason. Also useful for drivers that do device detection and | |
583 | * detection fails, either because the device uses an unexpected address, | |
584 | * or this is a compatible device with different ID register values. | |
585 | * | |
586 | * Parameter checking may look overzealous, but we really don't want | |
587 | * the user to provide incorrect parameters. | |
588 | */ | |
589 | static ssize_t | |
590 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
591 | const char *buf, size_t count) | |
592 | { | |
593 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
594 | struct i2c_board_info info; | |
595 | struct i2c_client *client; | |
596 | char *blank, end; | |
597 | int res; | |
598 | ||
599 | dev_warn(dev, "The new_device interface is still experimental " | |
600 | "and may change in a near future\n"); | |
601 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
602 | ||
603 | blank = strchr(buf, ' '); | |
604 | if (!blank) { | |
605 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
606 | return -EINVAL; | |
607 | } | |
608 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
609 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
610 | return -EINVAL; | |
611 | } | |
612 | memcpy(info.type, buf, blank - buf); | |
613 | ||
614 | /* Parse remaining parameters, reject extra parameters */ | |
615 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
616 | if (res < 1) { | |
617 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
618 | return -EINVAL; | |
619 | } | |
620 | if (res > 1 && end != '\n') { | |
621 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
622 | return -EINVAL; | |
623 | } | |
624 | ||
99cd8e25 JD |
625 | client = i2c_new_device(adap, &info); |
626 | if (!client) | |
3a89db5f | 627 | return -EINVAL; |
99cd8e25 JD |
628 | |
629 | /* Keep track of the added device */ | |
6629dcff JD |
630 | i2c_lock_adapter(adap); |
631 | list_add_tail(&client->detected, &adap->userspace_clients); | |
632 | i2c_unlock_adapter(adap); | |
99cd8e25 JD |
633 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
634 | info.type, info.addr); | |
635 | ||
636 | return count; | |
637 | } | |
638 | ||
639 | /* | |
640 | * And of course let the users delete the devices they instantiated, if | |
641 | * they got it wrong. This interface can only be used to delete devices | |
642 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
643 | * don't delete devices to which some kernel code still has references. | |
644 | * | |
645 | * Parameter checking may look overzealous, but we really don't want | |
646 | * the user to delete the wrong device. | |
647 | */ | |
648 | static ssize_t | |
649 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
650 | const char *buf, size_t count) | |
651 | { | |
652 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
653 | struct i2c_client *client, *next; | |
654 | unsigned short addr; | |
655 | char end; | |
656 | int res; | |
657 | ||
658 | /* Parse parameters, reject extra parameters */ | |
659 | res = sscanf(buf, "%hi%c", &addr, &end); | |
660 | if (res < 1) { | |
661 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
662 | return -EINVAL; | |
663 | } | |
664 | if (res > 1 && end != '\n') { | |
665 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
666 | return -EINVAL; | |
667 | } | |
668 | ||
669 | /* Make sure the device was added through sysfs */ | |
670 | res = -ENOENT; | |
6629dcff JD |
671 | i2c_lock_adapter(adap); |
672 | list_for_each_entry_safe(client, next, &adap->userspace_clients, | |
673 | detected) { | |
674 | if (client->addr == addr) { | |
99cd8e25 JD |
675 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
676 | "delete_device", client->name, client->addr); | |
677 | ||
678 | list_del(&client->detected); | |
679 | i2c_unregister_device(client); | |
680 | res = count; | |
681 | break; | |
682 | } | |
683 | } | |
6629dcff | 684 | i2c_unlock_adapter(adap); |
99cd8e25 JD |
685 | |
686 | if (res < 0) | |
687 | dev_err(dev, "%s: Can't find device in list\n", | |
688 | "delete_device"); | |
689 | return res; | |
690 | } | |
691 | ||
4f8cf824 JD |
692 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
693 | static DEVICE_ATTR(delete_device, S_IWUSR, NULL, i2c_sysfs_delete_device); | |
694 | ||
695 | static struct attribute *i2c_adapter_attrs[] = { | |
696 | &dev_attr_name.attr, | |
697 | &dev_attr_new_device.attr, | |
698 | &dev_attr_delete_device.attr, | |
699 | NULL | |
700 | }; | |
701 | ||
702 | static struct attribute_group i2c_adapter_attr_group = { | |
703 | .attrs = i2c_adapter_attrs, | |
704 | }; | |
705 | ||
706 | static const struct attribute_group *i2c_adapter_attr_groups[] = { | |
707 | &i2c_adapter_attr_group, | |
708 | NULL | |
16ffadfc | 709 | }; |
b119dc3f | 710 | |
4f8cf824 JD |
711 | static struct device_type i2c_adapter_type = { |
712 | .groups = i2c_adapter_attr_groups, | |
713 | .release = i2c_adapter_dev_release, | |
1da177e4 LT |
714 | }; |
715 | ||
2bb5095a JD |
716 | #ifdef CONFIG_I2C_COMPAT |
717 | static struct class_compat *i2c_adapter_compat_class; | |
718 | #endif | |
719 | ||
9c1600ed DB |
720 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
721 | { | |
722 | struct i2c_devinfo *devinfo; | |
723 | ||
f18c41da | 724 | down_read(&__i2c_board_lock); |
9c1600ed DB |
725 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
726 | if (devinfo->busnum == adapter->nr | |
727 | && !i2c_new_device(adapter, | |
728 | &devinfo->board_info)) | |
09b8ce0a ZX |
729 | dev_err(&adapter->dev, |
730 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
731 | devinfo->board_info.addr); |
732 | } | |
f18c41da | 733 | up_read(&__i2c_board_lock); |
9c1600ed DB |
734 | } |
735 | ||
69b0089a JD |
736 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
737 | struct i2c_adapter *adap) | |
026526f5 | 738 | { |
4735c98f JD |
739 | /* Detect supported devices on that bus, and instantiate them */ |
740 | i2c_detect(adap, driver); | |
741 | ||
742 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 JD |
743 | if (driver->attach_adapter) { |
744 | /* We ignore the return code; if it fails, too bad */ | |
745 | driver->attach_adapter(adap); | |
746 | } | |
747 | return 0; | |
748 | } | |
749 | ||
69b0089a JD |
750 | static int __process_new_adapter(struct device_driver *d, void *data) |
751 | { | |
752 | return i2c_do_add_adapter(to_i2c_driver(d), data); | |
753 | } | |
754 | ||
6e13e641 | 755 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 756 | { |
026526f5 | 757 | int res = 0, dummy; |
1da177e4 | 758 | |
1d0b19c9 | 759 | /* Can't register until after driver model init */ |
35fc37f8 JD |
760 | if (unlikely(WARN_ON(!i2c_bus_type.p))) { |
761 | res = -EAGAIN; | |
762 | goto out_list; | |
763 | } | |
1d0b19c9 | 764 | |
194684e5 | 765 | rt_mutex_init(&adap->bus_lock); |
6629dcff | 766 | INIT_LIST_HEAD(&adap->userspace_clients); |
1da177e4 | 767 | |
8fcfef6e JD |
768 | /* Set default timeout to 1 second if not already set */ |
769 | if (adap->timeout == 0) | |
770 | adap->timeout = HZ; | |
771 | ||
27d9c183 | 772 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
773 | adap->dev.bus = &i2c_bus_type; |
774 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 JD |
775 | res = device_register(&adap->dev); |
776 | if (res) | |
777 | goto out_list; | |
1da177e4 | 778 | |
b6d7b3d1 JD |
779 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
780 | ||
2bb5095a JD |
781 | #ifdef CONFIG_I2C_COMPAT |
782 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
783 | adap->dev.parent); | |
784 | if (res) | |
785 | dev_warn(&adap->dev, | |
786 | "Failed to create compatibility class link\n"); | |
787 | #endif | |
788 | ||
729d6dd5 | 789 | /* create pre-declared device nodes */ |
6e13e641 DB |
790 | if (adap->nr < __i2c_first_dynamic_bus_num) |
791 | i2c_scan_static_board_info(adap); | |
792 | ||
4735c98f | 793 | /* Notify drivers */ |
35fc37f8 | 794 | mutex_lock(&core_lock); |
026526f5 | 795 | dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 796 | __process_new_adapter); |
caada32a | 797 | mutex_unlock(&core_lock); |
35fc37f8 JD |
798 | |
799 | return 0; | |
b119c6c9 | 800 | |
b119c6c9 | 801 | out_list: |
35fc37f8 | 802 | mutex_lock(&core_lock); |
b119c6c9 | 803 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
804 | mutex_unlock(&core_lock); |
805 | return res; | |
1da177e4 LT |
806 | } |
807 | ||
6e13e641 DB |
808 | /** |
809 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
810 | * @adapter: the adapter to add | |
d64f73be | 811 | * Context: can sleep |
6e13e641 DB |
812 | * |
813 | * This routine is used to declare an I2C adapter when its bus number | |
814 | * doesn't matter. Examples: for I2C adapters dynamically added by | |
815 | * USB links or PCI plugin cards. | |
816 | * | |
817 | * When this returns zero, a new bus number was allocated and stored | |
818 | * in adap->nr, and the specified adapter became available for clients. | |
819 | * Otherwise, a negative errno value is returned. | |
820 | */ | |
821 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
822 | { | |
823 | int id, res = 0; | |
824 | ||
825 | retry: | |
826 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
827 | return -ENOMEM; | |
828 | ||
caada32a | 829 | mutex_lock(&core_lock); |
6e13e641 DB |
830 | /* "above" here means "above or equal to", sigh */ |
831 | res = idr_get_new_above(&i2c_adapter_idr, adapter, | |
832 | __i2c_first_dynamic_bus_num, &id); | |
caada32a | 833 | mutex_unlock(&core_lock); |
6e13e641 DB |
834 | |
835 | if (res < 0) { | |
836 | if (res == -EAGAIN) | |
837 | goto retry; | |
838 | return res; | |
839 | } | |
840 | ||
841 | adapter->nr = id; | |
842 | return i2c_register_adapter(adapter); | |
843 | } | |
844 | EXPORT_SYMBOL(i2c_add_adapter); | |
845 | ||
846 | /** | |
847 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
848 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 849 | * Context: can sleep |
6e13e641 DB |
850 | * |
851 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
852 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
853 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
854 | * is used to properly configure I2C devices. |
855 | * | |
856 | * If no devices have pre-been declared for this bus, then be sure to | |
857 | * register the adapter before any dynamically allocated ones. Otherwise | |
858 | * the required bus ID may not be available. | |
859 | * | |
860 | * When this returns zero, the specified adapter became available for | |
861 | * clients using the bus number provided in adap->nr. Also, the table | |
862 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
863 | * and the appropriate driver model device nodes are created. Otherwise, a | |
864 | * negative errno value is returned. | |
865 | */ | |
866 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
867 | { | |
868 | int id; | |
869 | int status; | |
870 | ||
871 | if (adap->nr & ~MAX_ID_MASK) | |
872 | return -EINVAL; | |
873 | ||
874 | retry: | |
875 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
876 | return -ENOMEM; | |
877 | ||
caada32a | 878 | mutex_lock(&core_lock); |
6e13e641 DB |
879 | /* "above" here means "above or equal to", sigh; |
880 | * we need the "equal to" result to force the result | |
881 | */ | |
882 | status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id); | |
883 | if (status == 0 && id != adap->nr) { | |
884 | status = -EBUSY; | |
885 | idr_remove(&i2c_adapter_idr, id); | |
886 | } | |
caada32a | 887 | mutex_unlock(&core_lock); |
6e13e641 DB |
888 | if (status == -EAGAIN) |
889 | goto retry; | |
890 | ||
891 | if (status == 0) | |
892 | status = i2c_register_adapter(adap); | |
893 | return status; | |
894 | } | |
895 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
896 | ||
69b0089a JD |
897 | static int i2c_do_del_adapter(struct i2c_driver *driver, |
898 | struct i2c_adapter *adapter) | |
026526f5 | 899 | { |
4735c98f | 900 | struct i2c_client *client, *_n; |
026526f5 JD |
901 | int res; |
902 | ||
acec211c JD |
903 | /* Remove the devices we created ourselves as the result of hardware |
904 | * probing (using a driver's detect method) */ | |
4735c98f JD |
905 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
906 | if (client->adapter == adapter) { | |
907 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
908 | client->name, client->addr); | |
909 | list_del(&client->detected); | |
910 | i2c_unregister_device(client); | |
911 | } | |
912 | } | |
913 | ||
026526f5 JD |
914 | if (!driver->detach_adapter) |
915 | return 0; | |
916 | res = driver->detach_adapter(adapter); | |
917 | if (res) | |
918 | dev_err(&adapter->dev, "detach_adapter failed (%d) " | |
919 | "for driver [%s]\n", res, driver->driver.name); | |
920 | return res; | |
921 | } | |
922 | ||
e549c2b5 JD |
923 | static int __unregister_client(struct device *dev, void *dummy) |
924 | { | |
925 | struct i2c_client *client = i2c_verify_client(dev); | |
926 | if (client) | |
927 | i2c_unregister_device(client); | |
928 | return 0; | |
929 | } | |
930 | ||
69b0089a JD |
931 | static int __process_removed_adapter(struct device_driver *d, void *data) |
932 | { | |
933 | return i2c_do_del_adapter(to_i2c_driver(d), data); | |
934 | } | |
935 | ||
d64f73be DB |
936 | /** |
937 | * i2c_del_adapter - unregister I2C adapter | |
938 | * @adap: the adapter being unregistered | |
939 | * Context: can sleep | |
940 | * | |
941 | * This unregisters an I2C adapter which was previously registered | |
942 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
943 | */ | |
1da177e4 LT |
944 | int i2c_del_adapter(struct i2c_adapter *adap) |
945 | { | |
1da177e4 | 946 | int res = 0; |
35fc37f8 | 947 | struct i2c_adapter *found; |
bbd2d9c9 | 948 | struct i2c_client *client, *next; |
1da177e4 LT |
949 | |
950 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
951 | mutex_lock(&core_lock); |
952 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
953 | mutex_unlock(&core_lock); | |
954 | if (found != adap) { | |
b6d7b3d1 JD |
955 | pr_debug("i2c-core: attempting to delete unregistered " |
956 | "adapter [%s]\n", adap->name); | |
35fc37f8 | 957 | return -EINVAL; |
1da177e4 LT |
958 | } |
959 | ||
026526f5 | 960 | /* Tell drivers about this removal */ |
35fc37f8 | 961 | mutex_lock(&core_lock); |
026526f5 | 962 | res = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 963 | __process_removed_adapter); |
35fc37f8 | 964 | mutex_unlock(&core_lock); |
026526f5 | 965 | if (res) |
35fc37f8 | 966 | return res; |
1da177e4 | 967 | |
bbd2d9c9 | 968 | /* Remove devices instantiated from sysfs */ |
6629dcff JD |
969 | i2c_lock_adapter(adap); |
970 | list_for_each_entry_safe(client, next, &adap->userspace_clients, | |
971 | detected) { | |
972 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, | |
973 | client->addr); | |
974 | list_del(&client->detected); | |
975 | i2c_unregister_device(client); | |
bbd2d9c9 | 976 | } |
6629dcff | 977 | i2c_unlock_adapter(adap); |
bbd2d9c9 | 978 | |
e549c2b5 JD |
979 | /* Detach any active clients. This can't fail, thus we do not |
980 | checking the returned value. */ | |
981 | res = device_for_each_child(&adap->dev, NULL, __unregister_client); | |
1da177e4 | 982 | |
2bb5095a JD |
983 | #ifdef CONFIG_I2C_COMPAT |
984 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
985 | adap->dev.parent); | |
986 | #endif | |
987 | ||
c5567521 TLSC |
988 | /* device name is gone after device_unregister */ |
989 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); | |
990 | ||
1da177e4 LT |
991 | /* clean up the sysfs representation */ |
992 | init_completion(&adap->dev_released); | |
1da177e4 | 993 | device_unregister(&adap->dev); |
1da177e4 LT |
994 | |
995 | /* wait for sysfs to drop all references */ | |
996 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 997 | |
6e13e641 | 998 | /* free bus id */ |
35fc37f8 | 999 | mutex_lock(&core_lock); |
1da177e4 | 1000 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 1001 | mutex_unlock(&core_lock); |
1da177e4 | 1002 | |
bd4bc3db JD |
1003 | /* Clear the device structure in case this adapter is ever going to be |
1004 | added again */ | |
1005 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
1006 | ||
35fc37f8 | 1007 | return 0; |
1da177e4 | 1008 | } |
c0564606 | 1009 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 LT |
1010 | |
1011 | ||
7b4fbc50 DB |
1012 | /* ------------------------------------------------------------------------- */ |
1013 | ||
69b0089a | 1014 | static int __process_new_driver(struct device *dev, void *data) |
7f101a97 | 1015 | { |
4f8cf824 JD |
1016 | if (dev->type != &i2c_adapter_type) |
1017 | return 0; | |
69b0089a | 1018 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
7f101a97 DY |
1019 | } |
1020 | ||
7b4fbc50 DB |
1021 | /* |
1022 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 1023 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
1024 | */ |
1025 | ||
de59cf9e | 1026 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 1027 | { |
7eebcb7c | 1028 | int res; |
1da177e4 | 1029 | |
1d0b19c9 DB |
1030 | /* Can't register until after driver model init */ |
1031 | if (unlikely(WARN_ON(!i2c_bus_type.p))) | |
1032 | return -EAGAIN; | |
1033 | ||
1da177e4 | 1034 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 1035 | driver->driver.owner = owner; |
1da177e4 | 1036 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 1037 | |
729d6dd5 | 1038 | /* When registration returns, the driver core |
6e13e641 DB |
1039 | * will have called probe() for all matching-but-unbound devices. |
1040 | */ | |
1da177e4 LT |
1041 | res = driver_register(&driver->driver); |
1042 | if (res) | |
7eebcb7c | 1043 | return res; |
438d6c2c | 1044 | |
35d8b2e6 | 1045 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 1046 | |
4735c98f JD |
1047 | INIT_LIST_HEAD(&driver->clients); |
1048 | /* Walk the adapters that are already present */ | |
35fc37f8 | 1049 | mutex_lock(&core_lock); |
69b0089a | 1050 | bus_for_each_dev(&i2c_bus_type, NULL, driver, __process_new_driver); |
7f101a97 | 1051 | mutex_unlock(&core_lock); |
35fc37f8 | 1052 | |
7f101a97 DY |
1053 | return 0; |
1054 | } | |
1055 | EXPORT_SYMBOL(i2c_register_driver); | |
1056 | ||
69b0089a | 1057 | static int __process_removed_driver(struct device *dev, void *data) |
7f101a97 | 1058 | { |
4f8cf824 JD |
1059 | if (dev->type != &i2c_adapter_type) |
1060 | return 0; | |
69b0089a | 1061 | return i2c_do_del_adapter(data, to_i2c_adapter(dev)); |
1da177e4 LT |
1062 | } |
1063 | ||
a1d9e6e4 DB |
1064 | /** |
1065 | * i2c_del_driver - unregister I2C driver | |
1066 | * @driver: the driver being unregistered | |
d64f73be | 1067 | * Context: can sleep |
a1d9e6e4 | 1068 | */ |
b3e82096 | 1069 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 1070 | { |
caada32a | 1071 | mutex_lock(&core_lock); |
69b0089a | 1072 | bus_for_each_dev(&i2c_bus_type, NULL, driver, __process_removed_driver); |
35fc37f8 | 1073 | mutex_unlock(&core_lock); |
1da177e4 LT |
1074 | |
1075 | driver_unregister(&driver->driver); | |
35d8b2e6 | 1076 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 1077 | } |
c0564606 | 1078 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 1079 | |
7b4fbc50 DB |
1080 | /* ------------------------------------------------------------------------- */ |
1081 | ||
e48d3319 JD |
1082 | /** |
1083 | * i2c_use_client - increments the reference count of the i2c client structure | |
1084 | * @client: the client being referenced | |
1085 | * | |
1086 | * Each live reference to a client should be refcounted. The driver model does | |
1087 | * that automatically as part of driver binding, so that most drivers don't | |
1088 | * need to do this explicitly: they hold a reference until they're unbound | |
1089 | * from the device. | |
1090 | * | |
1091 | * A pointer to the client with the incremented reference counter is returned. | |
1092 | */ | |
1093 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 1094 | { |
6ea438ec DB |
1095 | if (client && get_device(&client->dev)) |
1096 | return client; | |
1097 | return NULL; | |
1da177e4 | 1098 | } |
c0564606 | 1099 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 1100 | |
e48d3319 JD |
1101 | /** |
1102 | * i2c_release_client - release a use of the i2c client structure | |
1103 | * @client: the client being no longer referenced | |
1104 | * | |
1105 | * Must be called when a user of a client is finished with it. | |
1106 | */ | |
1107 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 1108 | { |
6ea438ec DB |
1109 | if (client) |
1110 | put_device(&client->dev); | |
1da177e4 | 1111 | } |
c0564606 | 1112 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 1113 | |
9b766b81 DB |
1114 | struct i2c_cmd_arg { |
1115 | unsigned cmd; | |
1116 | void *arg; | |
1117 | }; | |
1118 | ||
1119 | static int i2c_cmd(struct device *dev, void *_arg) | |
1120 | { | |
1121 | struct i2c_client *client = i2c_verify_client(dev); | |
1122 | struct i2c_cmd_arg *arg = _arg; | |
1123 | ||
1124 | if (client && client->driver && client->driver->command) | |
1125 | client->driver->command(client, arg->cmd, arg->arg); | |
1126 | return 0; | |
1127 | } | |
1128 | ||
1da177e4 LT |
1129 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
1130 | { | |
9b766b81 | 1131 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 1132 | |
9b766b81 DB |
1133 | cmd_arg.cmd = cmd; |
1134 | cmd_arg.arg = arg; | |
1135 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 1136 | } |
c0564606 | 1137 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
1138 | |
1139 | static int __init i2c_init(void) | |
1140 | { | |
1141 | int retval; | |
1142 | ||
1143 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
1144 | if (retval) |
1145 | return retval; | |
2bb5095a JD |
1146 | #ifdef CONFIG_I2C_COMPAT |
1147 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
1148 | if (!i2c_adapter_compat_class) { | |
1149 | retval = -ENOMEM; | |
1150 | goto bus_err; | |
1151 | } | |
1152 | #endif | |
e9f1373b DB |
1153 | retval = i2c_add_driver(&dummy_driver); |
1154 | if (retval) | |
2bb5095a | 1155 | goto class_err; |
e9f1373b DB |
1156 | return 0; |
1157 | ||
2bb5095a JD |
1158 | class_err: |
1159 | #ifdef CONFIG_I2C_COMPAT | |
1160 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 1161 | bus_err: |
2bb5095a | 1162 | #endif |
e9f1373b DB |
1163 | bus_unregister(&i2c_bus_type); |
1164 | return retval; | |
1da177e4 LT |
1165 | } |
1166 | ||
1167 | static void __exit i2c_exit(void) | |
1168 | { | |
e9f1373b | 1169 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
1170 | #ifdef CONFIG_I2C_COMPAT |
1171 | class_compat_unregister(i2c_adapter_compat_class); | |
1172 | #endif | |
1da177e4 LT |
1173 | bus_unregister(&i2c_bus_type); |
1174 | } | |
1175 | ||
a10f9e7c DB |
1176 | /* We must initialize early, because some subsystems register i2c drivers |
1177 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1178 | */ | |
1179 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1180 | module_exit(i2c_exit); |
1181 | ||
1182 | /* ---------------------------------------------------- | |
1183 | * the functional interface to the i2c busses. | |
1184 | * ---------------------------------------------------- | |
1185 | */ | |
1186 | ||
a1cdedac DB |
1187 | /** |
1188 | * i2c_transfer - execute a single or combined I2C message | |
1189 | * @adap: Handle to I2C bus | |
1190 | * @msgs: One or more messages to execute before STOP is issued to | |
1191 | * terminate the operation; each message begins with a START. | |
1192 | * @num: Number of messages to be executed. | |
1193 | * | |
1194 | * Returns negative errno, else the number of messages executed. | |
1195 | * | |
1196 | * Note that there is no requirement that each message be sent to | |
1197 | * the same slave address, although that is the most common model. | |
1198 | */ | |
09b8ce0a | 1199 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 1200 | { |
66b650f0 CW |
1201 | unsigned long orig_jiffies; |
1202 | int ret, try; | |
1da177e4 | 1203 | |
a1cdedac DB |
1204 | /* REVISIT the fault reporting model here is weak: |
1205 | * | |
1206 | * - When we get an error after receiving N bytes from a slave, | |
1207 | * there is no way to report "N". | |
1208 | * | |
1209 | * - When we get a NAK after transmitting N bytes to a slave, | |
1210 | * there is no way to report "N" ... or to let the master | |
1211 | * continue executing the rest of this combined message, if | |
1212 | * that's the appropriate response. | |
1213 | * | |
1214 | * - When for example "num" is two and we successfully complete | |
1215 | * the first message but get an error part way through the | |
1216 | * second, it's unclear whether that should be reported as | |
1217 | * one (discarding status on the second message) or errno | |
1218 | * (discarding status on the first one). | |
1219 | */ | |
1220 | ||
1da177e4 LT |
1221 | if (adap->algo->master_xfer) { |
1222 | #ifdef DEBUG | |
1223 | for (ret = 0; ret < num; ret++) { | |
1224 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
1225 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
1226 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
1227 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
1228 | } |
1229 | #endif | |
1230 | ||
cea443a8 | 1231 | if (in_atomic() || irqs_disabled()) { |
194684e5 | 1232 | ret = rt_mutex_trylock(&adap->bus_lock); |
cea443a8 MR |
1233 | if (!ret) |
1234 | /* I2C activity is ongoing. */ | |
1235 | return -EAGAIN; | |
1236 | } else { | |
194684e5 | 1237 | rt_mutex_lock(&adap->bus_lock); |
cea443a8 MR |
1238 | } |
1239 | ||
66b650f0 CW |
1240 | /* Retry automatically on arbitration loss */ |
1241 | orig_jiffies = jiffies; | |
1242 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
1243 | ret = adap->algo->master_xfer(adap, msgs, num); | |
1244 | if (ret != -EAGAIN) | |
1245 | break; | |
1246 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
1247 | break; | |
1248 | } | |
194684e5 | 1249 | rt_mutex_unlock(&adap->bus_lock); |
1da177e4 LT |
1250 | |
1251 | return ret; | |
1252 | } else { | |
1253 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1254 | return -EOPNOTSUPP; |
1da177e4 LT |
1255 | } |
1256 | } | |
c0564606 | 1257 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1258 | |
a1cdedac DB |
1259 | /** |
1260 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1261 | * @client: Handle to slave device | |
1262 | * @buf: Data that will be written to the slave | |
0c43ea54 | 1263 | * @count: How many bytes to write, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1264 | * |
1265 | * Returns negative errno, or else the number of bytes written. | |
1266 | */ | |
7225acf4 | 1267 | int i2c_master_send(struct i2c_client *client, const char *buf, int count) |
1da177e4 LT |
1268 | { |
1269 | int ret; | |
7225acf4 | 1270 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1271 | struct i2c_msg msg; |
1272 | ||
815f55f2 JD |
1273 | msg.addr = client->addr; |
1274 | msg.flags = client->flags & I2C_M_TEN; | |
1275 | msg.len = count; | |
1276 | msg.buf = (char *)buf; | |
438d6c2c | 1277 | |
815f55f2 | 1278 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1279 | |
815f55f2 JD |
1280 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes |
1281 | transmitted, else error code. */ | |
1282 | return (ret == 1) ? count : ret; | |
1da177e4 | 1283 | } |
c0564606 | 1284 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1285 | |
a1cdedac DB |
1286 | /** |
1287 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1288 | * @client: Handle to slave device | |
1289 | * @buf: Where to store data read from slave | |
0c43ea54 | 1290 | * @count: How many bytes to read, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1291 | * |
1292 | * Returns negative errno, or else the number of bytes read. | |
1293 | */ | |
7225acf4 | 1294 | int i2c_master_recv(struct i2c_client *client, char *buf, int count) |
1da177e4 | 1295 | { |
7225acf4 | 1296 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1297 | struct i2c_msg msg; |
1298 | int ret; | |
815f55f2 JD |
1299 | |
1300 | msg.addr = client->addr; | |
1301 | msg.flags = client->flags & I2C_M_TEN; | |
1302 | msg.flags |= I2C_M_RD; | |
1303 | msg.len = count; | |
1304 | msg.buf = buf; | |
1305 | ||
1306 | ret = i2c_transfer(adap, &msg, 1); | |
1307 | ||
1308 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1309 | transmitted, else error code. */ | |
1310 | return (ret == 1) ? count : ret; | |
1da177e4 | 1311 | } |
c0564606 | 1312 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1313 | |
1da177e4 LT |
1314 | /* ---------------------------------------------------- |
1315 | * the i2c address scanning function | |
1316 | * Will not work for 10-bit addresses! | |
1317 | * ---------------------------------------------------- | |
1318 | */ | |
1da177e4 | 1319 | |
63e4e802 JD |
1320 | /* |
1321 | * Legacy default probe function, mostly relevant for SMBus. The default | |
1322 | * probe method is a quick write, but it is known to corrupt the 24RF08 | |
1323 | * EEPROMs due to a state machine bug, and could also irreversibly | |
1324 | * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, | |
1325 | * we use a short byte read instead. Also, some bus drivers don't implement | |
1326 | * quick write, so we fallback to a byte read in that case too. | |
1327 | * On x86, there is another special case for FSC hardware monitoring chips, | |
1328 | * which want regular byte reads (address 0x73.) Fortunately, these are the | |
1329 | * only known chips using this I2C address on PC hardware. | |
1330 | * Returns 1 if probe succeeded, 0 if not. | |
1331 | */ | |
1332 | static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) | |
1333 | { | |
1334 | int err; | |
1335 | union i2c_smbus_data dummy; | |
1336 | ||
1337 | #ifdef CONFIG_X86 | |
1338 | if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) | |
1339 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) | |
1340 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1341 | I2C_SMBUS_BYTE_DATA, &dummy); | |
1342 | else | |
1343 | #endif | |
1344 | if ((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50 | |
1345 | || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) | |
1346 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1347 | I2C_SMBUS_BYTE, &dummy); | |
1348 | else | |
1349 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, | |
1350 | I2C_SMBUS_QUICK, NULL); | |
1351 | ||
1352 | return err >= 0; | |
1353 | } | |
1354 | ||
ccfbbd08 | 1355 | static int i2c_detect_address(struct i2c_client *temp_client, |
4735c98f JD |
1356 | struct i2c_driver *driver) |
1357 | { | |
1358 | struct i2c_board_info info; | |
1359 | struct i2c_adapter *adapter = temp_client->adapter; | |
1360 | int addr = temp_client->addr; | |
1361 | int err; | |
1362 | ||
1363 | /* Make sure the address is valid */ | |
656b8761 JD |
1364 | err = i2c_check_addr_validity(addr); |
1365 | if (err) { | |
4735c98f JD |
1366 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
1367 | addr); | |
656b8761 | 1368 | return err; |
4735c98f JD |
1369 | } |
1370 | ||
1371 | /* Skip if already in use */ | |
3b5f794b | 1372 | if (i2c_check_addr_busy(adapter, addr)) |
4735c98f JD |
1373 | return 0; |
1374 | ||
ccfbbd08 | 1375 | /* Make sure there is something at this address */ |
63e4e802 JD |
1376 | if (!i2c_default_probe(adapter, addr)) |
1377 | return 0; | |
4735c98f JD |
1378 | |
1379 | /* Finally call the custom detection function */ | |
1380 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
1381 | info.addr = addr; | |
310ec792 | 1382 | err = driver->detect(temp_client, &info); |
4735c98f JD |
1383 | if (err) { |
1384 | /* -ENODEV is returned if the detection fails. We catch it | |
1385 | here as this isn't an error. */ | |
1386 | return err == -ENODEV ? 0 : err; | |
1387 | } | |
1388 | ||
1389 | /* Consistency check */ | |
1390 | if (info.type[0] == '\0') { | |
1391 | dev_err(&adapter->dev, "%s detection function provided " | |
1392 | "no name for 0x%x\n", driver->driver.name, | |
1393 | addr); | |
1394 | } else { | |
1395 | struct i2c_client *client; | |
1396 | ||
1397 | /* Detection succeeded, instantiate the device */ | |
1398 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", | |
1399 | info.type, info.addr); | |
1400 | client = i2c_new_device(adapter, &info); | |
1401 | if (client) | |
1402 | list_add_tail(&client->detected, &driver->clients); | |
1403 | else | |
1404 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
1405 | info.type, info.addr); | |
1406 | } | |
1407 | return 0; | |
1408 | } | |
1409 | ||
1410 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
1411 | { | |
c3813d6a | 1412 | const unsigned short *address_list; |
4735c98f JD |
1413 | struct i2c_client *temp_client; |
1414 | int i, err = 0; | |
1415 | int adap_id = i2c_adapter_id(adapter); | |
1416 | ||
c3813d6a JD |
1417 | address_list = driver->address_list; |
1418 | if (!driver->detect || !address_list) | |
4735c98f JD |
1419 | return 0; |
1420 | ||
1421 | /* Set up a temporary client to help detect callback */ | |
1422 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
1423 | if (!temp_client) | |
1424 | return -ENOMEM; | |
1425 | temp_client->adapter = adapter; | |
1426 | ||
4329cf86 JD |
1427 | /* Stop here if the classes do not match */ |
1428 | if (!(adapter->class & driver->class)) | |
1429 | goto exit_free; | |
1430 | ||
827900c5 JD |
1431 | /* Stop here if the bus doesn't support probing */ |
1432 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE)) { | |
c3813d6a | 1433 | if (address_list[0] == I2C_CLIENT_END) |
4735c98f JD |
1434 | goto exit_free; |
1435 | ||
827900c5 | 1436 | dev_warn(&adapter->dev, "Probing not supported\n"); |
4735c98f JD |
1437 | err = -EOPNOTSUPP; |
1438 | goto exit_free; | |
1439 | } | |
1440 | ||
c3813d6a | 1441 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
4735c98f | 1442 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
c3813d6a JD |
1443 | "addr 0x%02x\n", adap_id, address_list[i]); |
1444 | temp_client->addr = address_list[i]; | |
ccfbbd08 | 1445 | err = i2c_detect_address(temp_client, driver); |
4735c98f JD |
1446 | if (err) |
1447 | goto exit_free; | |
1448 | } | |
1449 | ||
1450 | exit_free: | |
1451 | kfree(temp_client); | |
1452 | return err; | |
1453 | } | |
1454 | ||
12b5053a JD |
1455 | struct i2c_client * |
1456 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1457 | struct i2c_board_info *info, | |
1458 | unsigned short const *addr_list) | |
1459 | { | |
1460 | int i; | |
1461 | ||
1462 | /* Stop here if the bus doesn't support probing */ | |
1463 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { | |
1464 | dev_err(&adap->dev, "Probing not supported\n"); | |
1465 | return NULL; | |
1466 | } | |
1467 | ||
12b5053a JD |
1468 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1469 | /* Check address validity */ | |
656b8761 | 1470 | if (i2c_check_addr_validity(addr_list[i]) < 0) { |
12b5053a JD |
1471 | dev_warn(&adap->dev, "Invalid 7-bit address " |
1472 | "0x%02x\n", addr_list[i]); | |
1473 | continue; | |
1474 | } | |
1475 | ||
1476 | /* Check address availability */ | |
3b5f794b | 1477 | if (i2c_check_addr_busy(adap, addr_list[i])) { |
12b5053a JD |
1478 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1479 | "use, not probing\n", addr_list[i]); | |
1480 | continue; | |
1481 | } | |
1482 | ||
63e4e802 JD |
1483 | /* Test address responsiveness */ |
1484 | if (i2c_default_probe(adap, addr_list[i])) | |
1485 | break; | |
12b5053a | 1486 | } |
12b5053a JD |
1487 | |
1488 | if (addr_list[i] == I2C_CLIENT_END) { | |
1489 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1490 | return NULL; | |
1491 | } | |
1492 | ||
1493 | info->addr = addr_list[i]; | |
1494 | return i2c_new_device(adap, info); | |
1495 | } | |
1496 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
1497 | ||
7225acf4 | 1498 | struct i2c_adapter *i2c_get_adapter(int id) |
1da177e4 | 1499 | { |
1da177e4 | 1500 | struct i2c_adapter *adapter; |
438d6c2c | 1501 | |
caada32a | 1502 | mutex_lock(&core_lock); |
1cf92b45 | 1503 | adapter = idr_find(&i2c_adapter_idr, id); |
a0920e10 MH |
1504 | if (adapter && !try_module_get(adapter->owner)) |
1505 | adapter = NULL; | |
1506 | ||
caada32a | 1507 | mutex_unlock(&core_lock); |
a0920e10 | 1508 | return adapter; |
1da177e4 | 1509 | } |
c0564606 | 1510 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
1511 | |
1512 | void i2c_put_adapter(struct i2c_adapter *adap) | |
1513 | { | |
1514 | module_put(adap->owner); | |
1515 | } | |
c0564606 | 1516 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
1517 | |
1518 | /* The SMBus parts */ | |
1519 | ||
438d6c2c | 1520 | #define POLY (0x1070U << 3) |
09b8ce0a | 1521 | static u8 crc8(u16 data) |
1da177e4 LT |
1522 | { |
1523 | int i; | |
438d6c2c | 1524 | |
7225acf4 | 1525 | for (i = 0; i < 8; i++) { |
438d6c2c | 1526 | if (data & 0x8000) |
1da177e4 LT |
1527 | data = data ^ POLY; |
1528 | data = data << 1; | |
1529 | } | |
1530 | return (u8)(data >> 8); | |
1531 | } | |
1532 | ||
421ef47b JD |
1533 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
1534 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
1535 | { |
1536 | int i; | |
1537 | ||
7225acf4 | 1538 | for (i = 0; i < count; i++) |
421ef47b | 1539 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
1540 | return crc; |
1541 | } | |
1542 | ||
421ef47b JD |
1543 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
1544 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 1545 | { |
421ef47b JD |
1546 | /* The address will be sent first */ |
1547 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
1548 | pec = i2c_smbus_pec(pec, &addr, 1); | |
1549 | ||
1550 | /* The data buffer follows */ | |
1551 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
1552 | } |
1553 | ||
421ef47b JD |
1554 | /* Used for write only transactions */ |
1555 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 1556 | { |
421ef47b JD |
1557 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
1558 | msg->len++; | |
1da177e4 LT |
1559 | } |
1560 | ||
421ef47b JD |
1561 | /* Return <0 on CRC error |
1562 | If there was a write before this read (most cases) we need to take the | |
1563 | partial CRC from the write part into account. | |
1564 | Note that this function does modify the message (we need to decrease the | |
1565 | message length to hide the CRC byte from the caller). */ | |
1566 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 1567 | { |
421ef47b JD |
1568 | u8 rpec = msg->buf[--msg->len]; |
1569 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 1570 | |
1da177e4 LT |
1571 | if (rpec != cpec) { |
1572 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
1573 | rpec, cpec); | |
24a5bb7b | 1574 | return -EBADMSG; |
1da177e4 | 1575 | } |
438d6c2c | 1576 | return 0; |
1da177e4 LT |
1577 | } |
1578 | ||
a1cdedac DB |
1579 | /** |
1580 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
1581 | * @client: Handle to slave device | |
1582 | * | |
1583 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
1584 | * else the byte received from the device. | |
1585 | */ | |
1da177e4 LT |
1586 | s32 i2c_smbus_read_byte(struct i2c_client *client) |
1587 | { | |
1588 | union i2c_smbus_data data; | |
24a5bb7b DB |
1589 | int status; |
1590 | ||
1591 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1592 | I2C_SMBUS_READ, 0, | |
1593 | I2C_SMBUS_BYTE, &data); | |
1594 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1595 | } |
c0564606 | 1596 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 1597 | |
a1cdedac DB |
1598 | /** |
1599 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
1600 | * @client: Handle to slave device | |
1601 | * @value: Byte to be sent | |
1602 | * | |
1603 | * This executes the SMBus "send byte" protocol, returning negative errno | |
1604 | * else zero on success. | |
1605 | */ | |
1da177e4 LT |
1606 | s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) |
1607 | { | |
7225acf4 | 1608 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
421ef47b | 1609 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 1610 | } |
c0564606 | 1611 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 1612 | |
a1cdedac DB |
1613 | /** |
1614 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
1615 | * @client: Handle to slave device | |
1616 | * @command: Byte interpreted by slave | |
1617 | * | |
1618 | * This executes the SMBus "read byte" protocol, returning negative errno | |
1619 | * else a data byte received from the device. | |
1620 | */ | |
1da177e4 LT |
1621 | s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) |
1622 | { | |
1623 | union i2c_smbus_data data; | |
24a5bb7b DB |
1624 | int status; |
1625 | ||
1626 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1627 | I2C_SMBUS_READ, command, | |
1628 | I2C_SMBUS_BYTE_DATA, &data); | |
1629 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1630 | } |
c0564606 | 1631 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 1632 | |
a1cdedac DB |
1633 | /** |
1634 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
1635 | * @client: Handle to slave device | |
1636 | * @command: Byte interpreted by slave | |
1637 | * @value: Byte being written | |
1638 | * | |
1639 | * This executes the SMBus "write byte" protocol, returning negative errno | |
1640 | * else zero on success. | |
1641 | */ | |
1da177e4 LT |
1642 | s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) |
1643 | { | |
1644 | union i2c_smbus_data data; | |
1645 | data.byte = value; | |
7225acf4 FH |
1646 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1647 | I2C_SMBUS_WRITE, command, | |
1648 | I2C_SMBUS_BYTE_DATA, &data); | |
1da177e4 | 1649 | } |
c0564606 | 1650 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 1651 | |
a1cdedac DB |
1652 | /** |
1653 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
1654 | * @client: Handle to slave device | |
1655 | * @command: Byte interpreted by slave | |
1656 | * | |
1657 | * This executes the SMBus "read word" protocol, returning negative errno | |
1658 | * else a 16-bit unsigned "word" received from the device. | |
1659 | */ | |
1da177e4 LT |
1660 | s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) |
1661 | { | |
1662 | union i2c_smbus_data data; | |
24a5bb7b DB |
1663 | int status; |
1664 | ||
1665 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1666 | I2C_SMBUS_READ, command, | |
1667 | I2C_SMBUS_WORD_DATA, &data); | |
1668 | return (status < 0) ? status : data.word; | |
1da177e4 | 1669 | } |
c0564606 | 1670 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 1671 | |
a1cdedac DB |
1672 | /** |
1673 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
1674 | * @client: Handle to slave device | |
1675 | * @command: Byte interpreted by slave | |
1676 | * @value: 16-bit "word" being written | |
1677 | * | |
1678 | * This executes the SMBus "write word" protocol, returning negative errno | |
1679 | * else zero on success. | |
1680 | */ | |
1da177e4 LT |
1681 | s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) |
1682 | { | |
1683 | union i2c_smbus_data data; | |
1684 | data.word = value; | |
7225acf4 FH |
1685 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1686 | I2C_SMBUS_WRITE, command, | |
1687 | I2C_SMBUS_WORD_DATA, &data); | |
1da177e4 | 1688 | } |
c0564606 | 1689 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 1690 | |
596c88f4 PM |
1691 | /** |
1692 | * i2c_smbus_process_call - SMBus "process call" protocol | |
1693 | * @client: Handle to slave device | |
1694 | * @command: Byte interpreted by slave | |
1695 | * @value: 16-bit "word" being written | |
1696 | * | |
1697 | * This executes the SMBus "process call" protocol, returning negative errno | |
1698 | * else a 16-bit unsigned "word" received from the device. | |
1699 | */ | |
1700 | s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value) | |
1701 | { | |
1702 | union i2c_smbus_data data; | |
1703 | int status; | |
1704 | data.word = value; | |
1705 | ||
1706 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1707 | I2C_SMBUS_WRITE, command, | |
1708 | I2C_SMBUS_PROC_CALL, &data); | |
1709 | return (status < 0) ? status : data.word; | |
1710 | } | |
1711 | EXPORT_SYMBOL(i2c_smbus_process_call); | |
1712 | ||
a64ec07d | 1713 | /** |
a1cdedac | 1714 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 1715 | * @client: Handle to slave device |
a1cdedac | 1716 | * @command: Byte interpreted by slave |
a64ec07d DB |
1717 | * @values: Byte array into which data will be read; big enough to hold |
1718 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
1719 | * | |
a1cdedac DB |
1720 | * This executes the SMBus "block read" protocol, returning negative errno |
1721 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
1722 | * |
1723 | * Note that using this function requires that the client's adapter support | |
1724 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
1725 | * support this; its emulation through I2C messaging relies on a specific | |
1726 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
1727 | */ | |
b86a1bc8 JD |
1728 | s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, |
1729 | u8 *values) | |
1730 | { | |
1731 | union i2c_smbus_data data; | |
24a5bb7b | 1732 | int status; |
b86a1bc8 | 1733 | |
24a5bb7b DB |
1734 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1735 | I2C_SMBUS_READ, command, | |
1736 | I2C_SMBUS_BLOCK_DATA, &data); | |
1737 | if (status) | |
1738 | return status; | |
b86a1bc8 JD |
1739 | |
1740 | memcpy(values, &data.block[1], data.block[0]); | |
1741 | return data.block[0]; | |
1742 | } | |
1743 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
1744 | ||
a1cdedac DB |
1745 | /** |
1746 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
1747 | * @client: Handle to slave device | |
1748 | * @command: Byte interpreted by slave | |
1749 | * @length: Size of data block; SMBus allows at most 32 bytes | |
1750 | * @values: Byte array which will be written. | |
1751 | * | |
1752 | * This executes the SMBus "block write" protocol, returning negative errno | |
1753 | * else zero on success. | |
1754 | */ | |
1da177e4 | 1755 | s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1756 | u8 length, const u8 *values) |
1da177e4 LT |
1757 | { |
1758 | union i2c_smbus_data data; | |
7656032b | 1759 | |
1da177e4 LT |
1760 | if (length > I2C_SMBUS_BLOCK_MAX) |
1761 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 1762 | data.block[0] = length; |
7656032b | 1763 | memcpy(&data.block[1], values, length); |
7225acf4 FH |
1764 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1765 | I2C_SMBUS_WRITE, command, | |
1766 | I2C_SMBUS_BLOCK_DATA, &data); | |
1da177e4 | 1767 | } |
c0564606 | 1768 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
1769 | |
1770 | /* Returns the number of read bytes */ | |
4b2643d7 JD |
1771 | s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, |
1772 | u8 length, u8 *values) | |
1da177e4 LT |
1773 | { |
1774 | union i2c_smbus_data data; | |
24a5bb7b | 1775 | int status; |
7656032b | 1776 | |
4b2643d7 JD |
1777 | if (length > I2C_SMBUS_BLOCK_MAX) |
1778 | length = I2C_SMBUS_BLOCK_MAX; | |
1779 | data.block[0] = length; | |
24a5bb7b DB |
1780 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1781 | I2C_SMBUS_READ, command, | |
1782 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1783 | if (status < 0) | |
1784 | return status; | |
7656032b JD |
1785 | |
1786 | memcpy(values, &data.block[1], data.block[0]); | |
1787 | return data.block[0]; | |
1da177e4 | 1788 | } |
c0564606 | 1789 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 1790 | |
21bbd691 | 1791 | s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1792 | u8 length, const u8 *values) |
21bbd691 JD |
1793 | { |
1794 | union i2c_smbus_data data; | |
1795 | ||
1796 | if (length > I2C_SMBUS_BLOCK_MAX) | |
1797 | length = I2C_SMBUS_BLOCK_MAX; | |
1798 | data.block[0] = length; | |
1799 | memcpy(data.block + 1, values, length); | |
1800 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1801 | I2C_SMBUS_WRITE, command, | |
1802 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1803 | } | |
c0564606 | 1804 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 1805 | |
438d6c2c | 1806 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 1807 | No checking of parameters is done! */ |
7225acf4 FH |
1808 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, |
1809 | unsigned short flags, | |
1810 | char read_write, u8 command, int size, | |
1811 | union i2c_smbus_data *data) | |
1da177e4 LT |
1812 | { |
1813 | /* So we need to generate a series of msgs. In the case of writing, we | |
1814 | need to use only one message; when reading, we need two. We initialize | |
1815 | most things with sane defaults, to keep the code below somewhat | |
1816 | simpler. */ | |
5c50d188 HI |
1817 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
1818 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
7225acf4 | 1819 | int num = read_write == I2C_SMBUS_READ ? 2 : 1; |
438d6c2c | 1820 | struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 }, |
1da177e4 LT |
1821 | { addr, flags | I2C_M_RD, 0, msgbuf1 } |
1822 | }; | |
1823 | int i; | |
421ef47b | 1824 | u8 partial_pec = 0; |
24a5bb7b | 1825 | int status; |
1da177e4 LT |
1826 | |
1827 | msgbuf0[0] = command; | |
7225acf4 | 1828 | switch (size) { |
1da177e4 LT |
1829 | case I2C_SMBUS_QUICK: |
1830 | msg[0].len = 0; | |
1831 | /* Special case: The read/write field is used as data */ | |
f29d2e02 RK |
1832 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
1833 | I2C_M_RD : 0); | |
1da177e4 LT |
1834 | num = 1; |
1835 | break; | |
1836 | case I2C_SMBUS_BYTE: | |
1837 | if (read_write == I2C_SMBUS_READ) { | |
1838 | /* Special case: only a read! */ | |
1839 | msg[0].flags = I2C_M_RD | flags; | |
1840 | num = 1; | |
1841 | } | |
1842 | break; | |
1843 | case I2C_SMBUS_BYTE_DATA: | |
1844 | if (read_write == I2C_SMBUS_READ) | |
1845 | msg[1].len = 1; | |
1846 | else { | |
1847 | msg[0].len = 2; | |
1848 | msgbuf0[1] = data->byte; | |
1849 | } | |
1850 | break; | |
1851 | case I2C_SMBUS_WORD_DATA: | |
1852 | if (read_write == I2C_SMBUS_READ) | |
1853 | msg[1].len = 2; | |
1854 | else { | |
7225acf4 | 1855 | msg[0].len = 3; |
1da177e4 | 1856 | msgbuf0[1] = data->word & 0xff; |
7eff82c8 | 1857 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1858 | } |
1859 | break; | |
1860 | case I2C_SMBUS_PROC_CALL: | |
1861 | num = 2; /* Special case */ | |
1862 | read_write = I2C_SMBUS_READ; | |
1863 | msg[0].len = 3; | |
1864 | msg[1].len = 2; | |
1865 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1866 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1867 | break; |
1868 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 1869 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
1870 | msg[1].flags |= I2C_M_RECV_LEN; |
1871 | msg[1].len = 1; /* block length will be added by | |
1872 | the underlying bus driver */ | |
1da177e4 LT |
1873 | } else { |
1874 | msg[0].len = data->block[0] + 2; | |
1875 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
1876 | dev_err(&adapter->dev, |
1877 | "Invalid block write size %d\n", | |
1878 | data->block[0]); | |
1879 | return -EINVAL; | |
1da177e4 | 1880 | } |
5c50d188 | 1881 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
1882 | msgbuf0[i] = data->block[i-1]; |
1883 | } | |
1884 | break; | |
1885 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
1886 | num = 2; /* Another special case */ |
1887 | read_write = I2C_SMBUS_READ; | |
1888 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
1889 | dev_err(&adapter->dev, |
1890 | "Invalid block write size %d\n", | |
209d27c3 | 1891 | data->block[0]); |
24a5bb7b | 1892 | return -EINVAL; |
209d27c3 JD |
1893 | } |
1894 | msg[0].len = data->block[0] + 2; | |
1895 | for (i = 1; i < msg[0].len; i++) | |
1896 | msgbuf0[i] = data->block[i-1]; | |
1897 | msg[1].flags |= I2C_M_RECV_LEN; | |
1898 | msg[1].len = 1; /* block length will be added by | |
1899 | the underlying bus driver */ | |
1900 | break; | |
1da177e4 LT |
1901 | case I2C_SMBUS_I2C_BLOCK_DATA: |
1902 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 1903 | msg[1].len = data->block[0]; |
1da177e4 LT |
1904 | } else { |
1905 | msg[0].len = data->block[0] + 1; | |
30dac746 | 1906 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
1907 | dev_err(&adapter->dev, |
1908 | "Invalid block write size %d\n", | |
1909 | data->block[0]); | |
1910 | return -EINVAL; | |
1da177e4 LT |
1911 | } |
1912 | for (i = 1; i <= data->block[0]; i++) | |
1913 | msgbuf0[i] = data->block[i]; | |
1914 | } | |
1915 | break; | |
1916 | default: | |
24a5bb7b DB |
1917 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
1918 | return -EOPNOTSUPP; | |
1da177e4 LT |
1919 | } |
1920 | ||
421ef47b JD |
1921 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
1922 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
1923 | if (i) { | |
1924 | /* Compute PEC if first message is a write */ | |
1925 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 1926 | if (num == 1) /* Write only */ |
421ef47b JD |
1927 | i2c_smbus_add_pec(&msg[0]); |
1928 | else /* Write followed by read */ | |
1929 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
1930 | } | |
1931 | /* Ask for PEC if last message is a read */ | |
1932 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 1933 | msg[num-1].len++; |
421ef47b JD |
1934 | } |
1935 | ||
24a5bb7b DB |
1936 | status = i2c_transfer(adapter, msg, num); |
1937 | if (status < 0) | |
1938 | return status; | |
1da177e4 | 1939 | |
421ef47b JD |
1940 | /* Check PEC if last message is a read */ |
1941 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
1942 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
1943 | if (status < 0) | |
1944 | return status; | |
421ef47b JD |
1945 | } |
1946 | ||
1da177e4 | 1947 | if (read_write == I2C_SMBUS_READ) |
7225acf4 FH |
1948 | switch (size) { |
1949 | case I2C_SMBUS_BYTE: | |
1950 | data->byte = msgbuf0[0]; | |
1951 | break; | |
1952 | case I2C_SMBUS_BYTE_DATA: | |
1953 | data->byte = msgbuf1[0]; | |
1954 | break; | |
1955 | case I2C_SMBUS_WORD_DATA: | |
1956 | case I2C_SMBUS_PROC_CALL: | |
1957 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
1958 | break; | |
1959 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
1960 | for (i = 0; i < data->block[0]; i++) | |
1961 | data->block[i+1] = msgbuf1[i]; | |
1962 | break; | |
1963 | case I2C_SMBUS_BLOCK_DATA: | |
1964 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
1965 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
1966 | data->block[i] = msgbuf1[i]; | |
1967 | break; | |
1da177e4 LT |
1968 | } |
1969 | return 0; | |
1970 | } | |
1971 | ||
a1cdedac DB |
1972 | /** |
1973 | * i2c_smbus_xfer - execute SMBus protocol operations | |
1974 | * @adapter: Handle to I2C bus | |
1975 | * @addr: Address of SMBus slave on that bus | |
1976 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
1977 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
1978 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
1979 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
1980 | * @data: Data to be read or written | |
1981 | * | |
1982 | * This executes an SMBus protocol operation, and returns a negative | |
1983 | * errno code else zero on success. | |
1984 | */ | |
09b8ce0a | 1985 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
a1cdedac | 1986 | char read_write, u8 command, int protocol, |
09b8ce0a | 1987 | union i2c_smbus_data *data) |
1da177e4 | 1988 | { |
66b650f0 CW |
1989 | unsigned long orig_jiffies; |
1990 | int try; | |
1da177e4 | 1991 | s32 res; |
1da177e4 LT |
1992 | |
1993 | flags &= I2C_M_TEN | I2C_CLIENT_PEC; | |
1da177e4 LT |
1994 | |
1995 | if (adapter->algo->smbus_xfer) { | |
194684e5 | 1996 | rt_mutex_lock(&adapter->bus_lock); |
66b650f0 CW |
1997 | |
1998 | /* Retry automatically on arbitration loss */ | |
1999 | orig_jiffies = jiffies; | |
2000 | for (res = 0, try = 0; try <= adapter->retries; try++) { | |
2001 | res = adapter->algo->smbus_xfer(adapter, addr, flags, | |
2002 | read_write, command, | |
2003 | protocol, data); | |
2004 | if (res != -EAGAIN) | |
2005 | break; | |
2006 | if (time_after(jiffies, | |
2007 | orig_jiffies + adapter->timeout)) | |
2008 | break; | |
2009 | } | |
194684e5 | 2010 | rt_mutex_unlock(&adapter->bus_lock); |
1da177e4 | 2011 | } else |
7225acf4 | 2012 | res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, |
a1cdedac | 2013 | command, protocol, data); |
1da177e4 | 2014 | |
1da177e4 LT |
2015 | return res; |
2016 | } | |
1da177e4 | 2017 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
2018 | |
2019 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
2020 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
2021 | MODULE_LICENSE("GPL"); |