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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 | 22 | SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and |
0826374b ML |
23 | Jean Delvare <khali@linux-fr.org> |
24 | Mux support by Rodolfo Giometti <giometti@enneenne.com> and | |
25 | Michael Lawnick <michael.lawnick.ext@nsn.com> */ | |
1da177e4 | 26 | |
1da177e4 LT |
27 | #include <linux/module.h> |
28 | #include <linux/kernel.h> | |
29 | #include <linux/errno.h> | |
30 | #include <linux/slab.h> | |
31 | #include <linux/i2c.h> | |
32 | #include <linux/init.h> | |
33 | #include <linux/idr.h> | |
b3585e4f | 34 | #include <linux/mutex.h> |
959e85f7 | 35 | #include <linux/of_device.h> |
b8d6f45b | 36 | #include <linux/completion.h> |
cea443a8 MR |
37 | #include <linux/hardirq.h> |
38 | #include <linux/irqflags.h> | |
f18c41da | 39 | #include <linux/rwsem.h> |
6de468ae | 40 | #include <linux/pm_runtime.h> |
1da177e4 LT |
41 | #include <asm/uaccess.h> |
42 | ||
9c1600ed DB |
43 | #include "i2c-core.h" |
44 | ||
1da177e4 | 45 | |
6629dcff | 46 | /* core_lock protects i2c_adapter_idr, and guarantees |
35fc37f8 JD |
47 | that device detection, deletion of detected devices, and attach_adapter |
48 | and detach_adapter calls are serialized */ | |
caada32a | 49 | static DEFINE_MUTEX(core_lock); |
1da177e4 LT |
50 | static DEFINE_IDR(i2c_adapter_idr); |
51 | ||
4f8cf824 | 52 | static struct device_type i2c_client_type; |
4735c98f | 53 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
f37dd80a DB |
54 | |
55 | /* ------------------------------------------------------------------------- */ | |
56 | ||
d2653e92 JD |
57 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
58 | const struct i2c_client *client) | |
59 | { | |
60 | while (id->name[0]) { | |
61 | if (strcmp(client->name, id->name) == 0) | |
62 | return id; | |
63 | id++; | |
64 | } | |
65 | return NULL; | |
66 | } | |
67 | ||
1da177e4 LT |
68 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
69 | { | |
51298d12 JD |
70 | struct i2c_client *client = i2c_verify_client(dev); |
71 | struct i2c_driver *driver; | |
72 | ||
73 | if (!client) | |
74 | return 0; | |
7b4fbc50 | 75 | |
959e85f7 GL |
76 | /* Attempt an OF style match */ |
77 | if (of_driver_match_device(dev, drv)) | |
78 | return 1; | |
79 | ||
51298d12 | 80 | driver = to_i2c_driver(drv); |
d2653e92 JD |
81 | /* match on an id table if there is one */ |
82 | if (driver->id_table) | |
83 | return i2c_match_id(driver->id_table, client) != NULL; | |
84 | ||
eb8a7908 | 85 | return 0; |
1da177e4 LT |
86 | } |
87 | ||
7b4fbc50 DB |
88 | #ifdef CONFIG_HOTPLUG |
89 | ||
90 | /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ | |
7eff2e7a | 91 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 DB |
92 | { |
93 | struct i2c_client *client = to_i2c_client(dev); | |
7b4fbc50 | 94 | |
eb8a7908 JD |
95 | if (add_uevent_var(env, "MODALIAS=%s%s", |
96 | I2C_MODULE_PREFIX, client->name)) | |
97 | return -ENOMEM; | |
7b4fbc50 DB |
98 | dev_dbg(dev, "uevent\n"); |
99 | return 0; | |
100 | } | |
101 | ||
102 | #else | |
103 | #define i2c_device_uevent NULL | |
104 | #endif /* CONFIG_HOTPLUG */ | |
105 | ||
f37dd80a | 106 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 107 | { |
51298d12 JD |
108 | struct i2c_client *client = i2c_verify_client(dev); |
109 | struct i2c_driver *driver; | |
50c3304a | 110 | int status; |
7b4fbc50 | 111 | |
51298d12 JD |
112 | if (!client) |
113 | return 0; | |
114 | ||
115 | driver = to_i2c_driver(dev->driver); | |
e0457442 | 116 | if (!driver->probe || !driver->id_table) |
7b4fbc50 DB |
117 | return -ENODEV; |
118 | client->driver = driver; | |
ee35425c MP |
119 | if (!device_can_wakeup(&client->dev)) |
120 | device_init_wakeup(&client->dev, | |
121 | client->flags & I2C_CLIENT_WAKE); | |
7b4fbc50 | 122 | dev_dbg(dev, "probe\n"); |
d2653e92 | 123 | |
e0457442 | 124 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
e4a7b9b0 | 125 | if (status) { |
50c3304a | 126 | client->driver = NULL; |
e4a7b9b0 WS |
127 | i2c_set_clientdata(client, NULL); |
128 | } | |
50c3304a | 129 | return status; |
f37dd80a | 130 | } |
1da177e4 | 131 | |
f37dd80a DB |
132 | static int i2c_device_remove(struct device *dev) |
133 | { | |
51298d12 | 134 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 DB |
135 | struct i2c_driver *driver; |
136 | int status; | |
137 | ||
51298d12 | 138 | if (!client || !dev->driver) |
a1d9e6e4 DB |
139 | return 0; |
140 | ||
141 | driver = to_i2c_driver(dev->driver); | |
142 | if (driver->remove) { | |
143 | dev_dbg(dev, "remove\n"); | |
144 | status = driver->remove(client); | |
145 | } else { | |
146 | dev->driver = NULL; | |
147 | status = 0; | |
148 | } | |
e4a7b9b0 | 149 | if (status == 0) { |
a1d9e6e4 | 150 | client->driver = NULL; |
e4a7b9b0 WS |
151 | i2c_set_clientdata(client, NULL); |
152 | } | |
a1d9e6e4 | 153 | return status; |
1da177e4 LT |
154 | } |
155 | ||
f37dd80a | 156 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 157 | { |
51298d12 | 158 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
159 | struct i2c_driver *driver; |
160 | ||
51298d12 | 161 | if (!client || !dev->driver) |
f37dd80a DB |
162 | return; |
163 | driver = to_i2c_driver(dev->driver); | |
164 | if (driver->shutdown) | |
51298d12 | 165 | driver->shutdown(client); |
1da177e4 LT |
166 | } |
167 | ||
2f60ba70 RW |
168 | #ifdef CONFIG_PM_SLEEP |
169 | static int i2c_legacy_suspend(struct device *dev, pm_message_t mesg) | |
54067ee2 | 170 | { |
2f60ba70 RW |
171 | struct i2c_client *client = i2c_verify_client(dev); |
172 | struct i2c_driver *driver; | |
54067ee2 | 173 | |
2f60ba70 | 174 | if (!client || !dev->driver) |
54067ee2 | 175 | return 0; |
2f60ba70 RW |
176 | driver = to_i2c_driver(dev->driver); |
177 | if (!driver->suspend) | |
54067ee2 | 178 | return 0; |
2f60ba70 | 179 | return driver->suspend(client, mesg); |
54067ee2 | 180 | } |
181 | ||
2f60ba70 | 182 | static int i2c_legacy_resume(struct device *dev) |
54067ee2 | 183 | { |
2f60ba70 RW |
184 | struct i2c_client *client = i2c_verify_client(dev); |
185 | struct i2c_driver *driver; | |
54067ee2 | 186 | |
2f60ba70 | 187 | if (!client || !dev->driver) |
54067ee2 | 188 | return 0; |
2f60ba70 RW |
189 | driver = to_i2c_driver(dev->driver); |
190 | if (!driver->resume) | |
54067ee2 | 191 | return 0; |
2f60ba70 | 192 | return driver->resume(client); |
54067ee2 | 193 | } |
54067ee2 | 194 | |
2f60ba70 | 195 | static int i2c_device_pm_suspend(struct device *dev) |
6de468ae | 196 | { |
2f60ba70 | 197 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 198 | |
64b4782f RN |
199 | if (pm) { |
200 | if (pm_runtime_suspended(dev)) | |
201 | return 0; | |
202 | else | |
203 | return pm->suspend ? pm->suspend(dev) : 0; | |
204 | } | |
6de468ae | 205 | |
2f60ba70 | 206 | return i2c_legacy_suspend(dev, PMSG_SUSPEND); |
6de468ae MB |
207 | } |
208 | ||
2f60ba70 | 209 | static int i2c_device_pm_resume(struct device *dev) |
6de468ae | 210 | { |
2f60ba70 | 211 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae MB |
212 | int ret; |
213 | ||
2f60ba70 RW |
214 | if (pm) |
215 | ret = pm->resume ? pm->resume(dev) : 0; | |
216 | else | |
217 | ret = i2c_legacy_resume(dev); | |
218 | ||
2f60ba70 | 219 | return ret; |
6de468ae | 220 | } |
6de468ae | 221 | |
2f60ba70 | 222 | static int i2c_device_pm_freeze(struct device *dev) |
1da177e4 | 223 | { |
2f60ba70 | 224 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 225 | |
64b4782f RN |
226 | if (pm) { |
227 | if (pm_runtime_suspended(dev)) | |
228 | return 0; | |
229 | else | |
230 | return pm->freeze ? pm->freeze(dev) : 0; | |
231 | } | |
2f60ba70 RW |
232 | |
233 | return i2c_legacy_suspend(dev, PMSG_FREEZE); | |
1da177e4 LT |
234 | } |
235 | ||
2f60ba70 | 236 | static int i2c_device_pm_thaw(struct device *dev) |
1da177e4 | 237 | { |
2f60ba70 | 238 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 239 | |
64b4782f RN |
240 | if (pm) { |
241 | if (pm_runtime_suspended(dev)) | |
242 | return 0; | |
243 | else | |
244 | return pm->thaw ? pm->thaw(dev) : 0; | |
245 | } | |
2f60ba70 RW |
246 | |
247 | return i2c_legacy_resume(dev); | |
248 | } | |
249 | ||
250 | static int i2c_device_pm_poweroff(struct device *dev) | |
251 | { | |
252 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
253 | ||
64b4782f RN |
254 | if (pm) { |
255 | if (pm_runtime_suspended(dev)) | |
256 | return 0; | |
257 | else | |
258 | return pm->poweroff ? pm->poweroff(dev) : 0; | |
259 | } | |
2f60ba70 RW |
260 | |
261 | return i2c_legacy_suspend(dev, PMSG_HIBERNATE); | |
262 | } | |
263 | ||
264 | static int i2c_device_pm_restore(struct device *dev) | |
265 | { | |
266 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
267 | int ret; | |
268 | ||
269 | if (pm) | |
270 | ret = pm->restore ? pm->restore(dev) : 0; | |
271 | else | |
272 | ret = i2c_legacy_resume(dev); | |
273 | ||
274 | if (!ret) { | |
275 | pm_runtime_disable(dev); | |
276 | pm_runtime_set_active(dev); | |
277 | pm_runtime_enable(dev); | |
278 | } | |
279 | ||
280 | return ret; | |
1da177e4 | 281 | } |
2f60ba70 RW |
282 | #else /* !CONFIG_PM_SLEEP */ |
283 | #define i2c_device_pm_suspend NULL | |
284 | #define i2c_device_pm_resume NULL | |
285 | #define i2c_device_pm_freeze NULL | |
286 | #define i2c_device_pm_thaw NULL | |
287 | #define i2c_device_pm_poweroff NULL | |
288 | #define i2c_device_pm_restore NULL | |
289 | #endif /* !CONFIG_PM_SLEEP */ | |
1da177e4 | 290 | |
9c1600ed DB |
291 | static void i2c_client_dev_release(struct device *dev) |
292 | { | |
293 | kfree(to_i2c_client(dev)); | |
294 | } | |
295 | ||
09b8ce0a | 296 | static ssize_t |
4f8cf824 | 297 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 298 | { |
4f8cf824 JD |
299 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
300 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 DB |
301 | } |
302 | ||
09b8ce0a ZX |
303 | static ssize_t |
304 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
305 | { |
306 | struct i2c_client *client = to_i2c_client(dev); | |
eb8a7908 | 307 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
308 | } |
309 | ||
4f8cf824 | 310 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
51298d12 JD |
311 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
312 | ||
313 | static struct attribute *i2c_dev_attrs[] = { | |
314 | &dev_attr_name.attr, | |
7b4fbc50 | 315 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
316 | &dev_attr_modalias.attr, |
317 | NULL | |
318 | }; | |
319 | ||
320 | static struct attribute_group i2c_dev_attr_group = { | |
321 | .attrs = i2c_dev_attrs, | |
322 | }; | |
323 | ||
324 | static const struct attribute_group *i2c_dev_attr_groups[] = { | |
325 | &i2c_dev_attr_group, | |
326 | NULL | |
7b4fbc50 DB |
327 | }; |
328 | ||
0b2c3688 | 329 | static const struct dev_pm_ops i2c_device_pm_ops = { |
54067ee2 | 330 | .suspend = i2c_device_pm_suspend, |
331 | .resume = i2c_device_pm_resume, | |
2f60ba70 RW |
332 | .freeze = i2c_device_pm_freeze, |
333 | .thaw = i2c_device_pm_thaw, | |
334 | .poweroff = i2c_device_pm_poweroff, | |
335 | .restore = i2c_device_pm_restore, | |
336 | SET_RUNTIME_PM_OPS( | |
337 | pm_generic_runtime_suspend, | |
338 | pm_generic_runtime_resume, | |
339 | pm_generic_runtime_idle | |
340 | ) | |
54067ee2 | 341 | }; |
342 | ||
e9ca9eb9 | 343 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
344 | .name = "i2c", |
345 | .match = i2c_device_match, | |
346 | .probe = i2c_device_probe, | |
347 | .remove = i2c_device_remove, | |
348 | .shutdown = i2c_device_shutdown, | |
54067ee2 | 349 | .pm = &i2c_device_pm_ops, |
b864c7d5 | 350 | }; |
e9ca9eb9 | 351 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 352 | |
51298d12 JD |
353 | static struct device_type i2c_client_type = { |
354 | .groups = i2c_dev_attr_groups, | |
355 | .uevent = i2c_device_uevent, | |
356 | .release = i2c_client_dev_release, | |
357 | }; | |
358 | ||
9b766b81 DB |
359 | |
360 | /** | |
361 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
362 | * @dev: device, probably from some driver model iterator | |
363 | * | |
364 | * When traversing the driver model tree, perhaps using driver model | |
365 | * iterators like @device_for_each_child(), you can't assume very much | |
366 | * about the nodes you find. Use this function to avoid oopses caused | |
367 | * by wrongly treating some non-I2C device as an i2c_client. | |
368 | */ | |
369 | struct i2c_client *i2c_verify_client(struct device *dev) | |
370 | { | |
51298d12 | 371 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
372 | ? to_i2c_client(dev) |
373 | : NULL; | |
374 | } | |
375 | EXPORT_SYMBOL(i2c_verify_client); | |
376 | ||
377 | ||
3a89db5f JD |
378 | /* This is a permissive address validity check, I2C address map constraints |
379 | * are purposedly not enforced, except for the general call address. */ | |
380 | static int i2c_check_client_addr_validity(const struct i2c_client *client) | |
381 | { | |
382 | if (client->flags & I2C_CLIENT_TEN) { | |
383 | /* 10-bit address, all values are valid */ | |
384 | if (client->addr > 0x3ff) | |
385 | return -EINVAL; | |
386 | } else { | |
387 | /* 7-bit address, reject the general call address */ | |
388 | if (client->addr == 0x00 || client->addr > 0x7f) | |
389 | return -EINVAL; | |
390 | } | |
391 | return 0; | |
392 | } | |
393 | ||
656b8761 JD |
394 | /* And this is a strict address validity check, used when probing. If a |
395 | * device uses a reserved address, then it shouldn't be probed. 7-bit | |
396 | * addressing is assumed, 10-bit address devices are rare and should be | |
397 | * explicitly enumerated. */ | |
398 | static int i2c_check_addr_validity(unsigned short addr) | |
399 | { | |
400 | /* | |
401 | * Reserved addresses per I2C specification: | |
402 | * 0x00 General call address / START byte | |
403 | * 0x01 CBUS address | |
404 | * 0x02 Reserved for different bus format | |
405 | * 0x03 Reserved for future purposes | |
406 | * 0x04-0x07 Hs-mode master code | |
407 | * 0x78-0x7b 10-bit slave addressing | |
408 | * 0x7c-0x7f Reserved for future purposes | |
409 | */ | |
410 | if (addr < 0x08 || addr > 0x77) | |
411 | return -EINVAL; | |
412 | return 0; | |
413 | } | |
414 | ||
3b5f794b JD |
415 | static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
416 | { | |
417 | struct i2c_client *client = i2c_verify_client(dev); | |
418 | int addr = *(int *)addrp; | |
419 | ||
420 | if (client && client->addr == addr) | |
421 | return -EBUSY; | |
422 | return 0; | |
423 | } | |
424 | ||
0826374b ML |
425 | /* walk up mux tree */ |
426 | static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
427 | { | |
97cc4d49 | 428 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
429 | int result; |
430 | ||
431 | result = device_for_each_child(&adapter->dev, &addr, | |
432 | __i2c_check_addr_busy); | |
433 | ||
97cc4d49 JD |
434 | if (!result && parent) |
435 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
436 | |
437 | return result; | |
438 | } | |
439 | ||
440 | /* recurse down mux tree */ | |
441 | static int i2c_check_mux_children(struct device *dev, void *addrp) | |
442 | { | |
443 | int result; | |
444 | ||
445 | if (dev->type == &i2c_adapter_type) | |
446 | result = device_for_each_child(dev, addrp, | |
447 | i2c_check_mux_children); | |
448 | else | |
449 | result = __i2c_check_addr_busy(dev, addrp); | |
450 | ||
451 | return result; | |
452 | } | |
453 | ||
3b5f794b JD |
454 | static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) |
455 | { | |
97cc4d49 | 456 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
457 | int result = 0; |
458 | ||
97cc4d49 JD |
459 | if (parent) |
460 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
461 | |
462 | if (!result) | |
463 | result = device_for_each_child(&adapter->dev, &addr, | |
464 | i2c_check_mux_children); | |
465 | ||
466 | return result; | |
3b5f794b JD |
467 | } |
468 | ||
fe61e07e JD |
469 | /** |
470 | * i2c_lock_adapter - Get exclusive access to an I2C bus segment | |
471 | * @adapter: Target I2C bus segment | |
472 | */ | |
473 | void i2c_lock_adapter(struct i2c_adapter *adapter) | |
474 | { | |
97cc4d49 JD |
475 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
476 | ||
477 | if (parent) | |
478 | i2c_lock_adapter(parent); | |
0826374b ML |
479 | else |
480 | rt_mutex_lock(&adapter->bus_lock); | |
fe61e07e JD |
481 | } |
482 | EXPORT_SYMBOL_GPL(i2c_lock_adapter); | |
483 | ||
484 | /** | |
485 | * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment | |
486 | * @adapter: Target I2C bus segment | |
487 | */ | |
488 | static int i2c_trylock_adapter(struct i2c_adapter *adapter) | |
489 | { | |
97cc4d49 JD |
490 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
491 | ||
492 | if (parent) | |
493 | return i2c_trylock_adapter(parent); | |
0826374b ML |
494 | else |
495 | return rt_mutex_trylock(&adapter->bus_lock); | |
fe61e07e JD |
496 | } |
497 | ||
498 | /** | |
499 | * i2c_unlock_adapter - Release exclusive access to an I2C bus segment | |
500 | * @adapter: Target I2C bus segment | |
501 | */ | |
502 | void i2c_unlock_adapter(struct i2c_adapter *adapter) | |
503 | { | |
97cc4d49 JD |
504 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
505 | ||
506 | if (parent) | |
507 | i2c_unlock_adapter(parent); | |
0826374b ML |
508 | else |
509 | rt_mutex_unlock(&adapter->bus_lock); | |
fe61e07e JD |
510 | } |
511 | EXPORT_SYMBOL_GPL(i2c_unlock_adapter); | |
512 | ||
9c1600ed | 513 | /** |
f8a227e8 | 514 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
515 | * @adap: the adapter managing the device |
516 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 517 | * Context: can sleep |
9c1600ed | 518 | * |
f8a227e8 JD |
519 | * Create an i2c device. Binding is handled through driver model |
520 | * probe()/remove() methods. A driver may be bound to this device when we | |
521 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
522 | * load the driver module). This call is not appropriate for use by mainboard | |
523 | * initialization logic, which usually runs during an arch_initcall() long | |
524 | * before any i2c_adapter could exist. | |
9c1600ed DB |
525 | * |
526 | * This returns the new i2c client, which may be saved for later use with | |
527 | * i2c_unregister_device(); or NULL to indicate an error. | |
528 | */ | |
529 | struct i2c_client * | |
530 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
531 | { | |
532 | struct i2c_client *client; | |
533 | int status; | |
534 | ||
535 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
536 | if (!client) | |
537 | return NULL; | |
538 | ||
539 | client->adapter = adap; | |
540 | ||
541 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 542 | |
11f1f2af AV |
543 | if (info->archdata) |
544 | client->dev.archdata = *info->archdata; | |
545 | ||
ee35425c | 546 | client->flags = info->flags; |
9c1600ed DB |
547 | client->addr = info->addr; |
548 | client->irq = info->irq; | |
549 | ||
9c1600ed DB |
550 | strlcpy(client->name, info->type, sizeof(client->name)); |
551 | ||
3a89db5f JD |
552 | /* Check for address validity */ |
553 | status = i2c_check_client_addr_validity(client); | |
554 | if (status) { | |
555 | dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", | |
556 | client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); | |
557 | goto out_err_silent; | |
558 | } | |
559 | ||
f8a227e8 | 560 | /* Check for address business */ |
3b5f794b | 561 | status = i2c_check_addr_busy(adap, client->addr); |
f8a227e8 JD |
562 | if (status) |
563 | goto out_err; | |
564 | ||
565 | client->dev.parent = &client->adapter->dev; | |
566 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 567 | client->dev.type = &i2c_client_type; |
d12d42f7 GL |
568 | #ifdef CONFIG_OF |
569 | client->dev.of_node = info->of_node; | |
570 | #endif | |
f8a227e8 JD |
571 | |
572 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), | |
573 | client->addr); | |
574 | status = device_register(&client->dev); | |
575 | if (status) | |
576 | goto out_err; | |
577 | ||
f8a227e8 JD |
578 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
579 | client->name, dev_name(&client->dev)); | |
580 | ||
9c1600ed | 581 | return client; |
f8a227e8 JD |
582 | |
583 | out_err: | |
584 | dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " | |
585 | "(%d)\n", client->name, client->addr, status); | |
3a89db5f | 586 | out_err_silent: |
f8a227e8 JD |
587 | kfree(client); |
588 | return NULL; | |
9c1600ed DB |
589 | } |
590 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
591 | ||
592 | ||
593 | /** | |
594 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
595 | * @client: value returned from i2c_new_device() | |
d64f73be | 596 | * Context: can sleep |
9c1600ed DB |
597 | */ |
598 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 599 | { |
a1d9e6e4 DB |
600 | device_unregister(&client->dev); |
601 | } | |
9c1600ed | 602 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
603 | |
604 | ||
60b129d7 JD |
605 | static const struct i2c_device_id dummy_id[] = { |
606 | { "dummy", 0 }, | |
607 | { }, | |
608 | }; | |
609 | ||
d2653e92 JD |
610 | static int dummy_probe(struct i2c_client *client, |
611 | const struct i2c_device_id *id) | |
612 | { | |
613 | return 0; | |
614 | } | |
615 | ||
616 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
617 | { |
618 | return 0; | |
619 | } | |
620 | ||
621 | static struct i2c_driver dummy_driver = { | |
622 | .driver.name = "dummy", | |
d2653e92 JD |
623 | .probe = dummy_probe, |
624 | .remove = dummy_remove, | |
60b129d7 | 625 | .id_table = dummy_id, |
e9f1373b DB |
626 | }; |
627 | ||
628 | /** | |
629 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
630 | * @adapter: the adapter managing the device | |
631 | * @address: seven bit address to be used | |
e9f1373b DB |
632 | * Context: can sleep |
633 | * | |
634 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
635 | * with devices that consume multiple addresses. Examples of such chips | |
636 | * include various EEPROMS (like 24c04 and 24c08 models). | |
637 | * | |
638 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
639 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
640 | * And second, this prevents the specified address from being bound to a | |
641 | * different driver. | |
642 | * | |
643 | * This returns the new i2c client, which should be saved for later use with | |
644 | * i2c_unregister_device(); or NULL to indicate an error. | |
645 | */ | |
09b8ce0a | 646 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
647 | { |
648 | struct i2c_board_info info = { | |
60b129d7 | 649 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
650 | }; |
651 | ||
e9f1373b DB |
652 | return i2c_new_device(adapter, &info); |
653 | } | |
654 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
655 | ||
f37dd80a DB |
656 | /* ------------------------------------------------------------------------- */ |
657 | ||
16ffadfc DB |
658 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
659 | ||
83eaaed0 | 660 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 661 | { |
ef2c8321 | 662 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
663 | complete(&adap->dev_released); |
664 | } | |
665 | ||
99cd8e25 JD |
666 | /* |
667 | * Let users instantiate I2C devices through sysfs. This can be used when | |
668 | * platform initialization code doesn't contain the proper data for | |
669 | * whatever reason. Also useful for drivers that do device detection and | |
670 | * detection fails, either because the device uses an unexpected address, | |
671 | * or this is a compatible device with different ID register values. | |
672 | * | |
673 | * Parameter checking may look overzealous, but we really don't want | |
674 | * the user to provide incorrect parameters. | |
675 | */ | |
676 | static ssize_t | |
677 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
678 | const char *buf, size_t count) | |
679 | { | |
680 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
681 | struct i2c_board_info info; | |
682 | struct i2c_client *client; | |
683 | char *blank, end; | |
684 | int res; | |
685 | ||
99cd8e25 JD |
686 | memset(&info, 0, sizeof(struct i2c_board_info)); |
687 | ||
688 | blank = strchr(buf, ' '); | |
689 | if (!blank) { | |
690 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
691 | return -EINVAL; | |
692 | } | |
693 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
694 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
695 | return -EINVAL; | |
696 | } | |
697 | memcpy(info.type, buf, blank - buf); | |
698 | ||
699 | /* Parse remaining parameters, reject extra parameters */ | |
700 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
701 | if (res < 1) { | |
702 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
703 | return -EINVAL; | |
704 | } | |
705 | if (res > 1 && end != '\n') { | |
706 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
707 | return -EINVAL; | |
708 | } | |
709 | ||
99cd8e25 JD |
710 | client = i2c_new_device(adap, &info); |
711 | if (!client) | |
3a89db5f | 712 | return -EINVAL; |
99cd8e25 JD |
713 | |
714 | /* Keep track of the added device */ | |
dafc50d1 | 715 | mutex_lock(&adap->userspace_clients_lock); |
6629dcff | 716 | list_add_tail(&client->detected, &adap->userspace_clients); |
dafc50d1 | 717 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
718 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
719 | info.type, info.addr); | |
720 | ||
721 | return count; | |
722 | } | |
723 | ||
724 | /* | |
725 | * And of course let the users delete the devices they instantiated, if | |
726 | * they got it wrong. This interface can only be used to delete devices | |
727 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
728 | * don't delete devices to which some kernel code still has references. | |
729 | * | |
730 | * Parameter checking may look overzealous, but we really don't want | |
731 | * the user to delete the wrong device. | |
732 | */ | |
733 | static ssize_t | |
734 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
735 | const char *buf, size_t count) | |
736 | { | |
737 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
738 | struct i2c_client *client, *next; | |
739 | unsigned short addr; | |
740 | char end; | |
741 | int res; | |
742 | ||
743 | /* Parse parameters, reject extra parameters */ | |
744 | res = sscanf(buf, "%hi%c", &addr, &end); | |
745 | if (res < 1) { | |
746 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
747 | return -EINVAL; | |
748 | } | |
749 | if (res > 1 && end != '\n') { | |
750 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
751 | return -EINVAL; | |
752 | } | |
753 | ||
754 | /* Make sure the device was added through sysfs */ | |
755 | res = -ENOENT; | |
dafc50d1 | 756 | mutex_lock(&adap->userspace_clients_lock); |
6629dcff JD |
757 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
758 | detected) { | |
759 | if (client->addr == addr) { | |
99cd8e25 JD |
760 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
761 | "delete_device", client->name, client->addr); | |
762 | ||
763 | list_del(&client->detected); | |
764 | i2c_unregister_device(client); | |
765 | res = count; | |
766 | break; | |
767 | } | |
768 | } | |
dafc50d1 | 769 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
770 | |
771 | if (res < 0) | |
772 | dev_err(dev, "%s: Can't find device in list\n", | |
773 | "delete_device"); | |
774 | return res; | |
775 | } | |
776 | ||
4f8cf824 JD |
777 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
778 | static DEVICE_ATTR(delete_device, S_IWUSR, NULL, i2c_sysfs_delete_device); | |
779 | ||
780 | static struct attribute *i2c_adapter_attrs[] = { | |
781 | &dev_attr_name.attr, | |
782 | &dev_attr_new_device.attr, | |
783 | &dev_attr_delete_device.attr, | |
784 | NULL | |
785 | }; | |
786 | ||
787 | static struct attribute_group i2c_adapter_attr_group = { | |
788 | .attrs = i2c_adapter_attrs, | |
789 | }; | |
790 | ||
791 | static const struct attribute_group *i2c_adapter_attr_groups[] = { | |
792 | &i2c_adapter_attr_group, | |
793 | NULL | |
16ffadfc | 794 | }; |
b119dc3f | 795 | |
0826374b | 796 | struct device_type i2c_adapter_type = { |
4f8cf824 JD |
797 | .groups = i2c_adapter_attr_groups, |
798 | .release = i2c_adapter_dev_release, | |
1da177e4 | 799 | }; |
0826374b | 800 | EXPORT_SYMBOL_GPL(i2c_adapter_type); |
1da177e4 | 801 | |
2bb5095a JD |
802 | #ifdef CONFIG_I2C_COMPAT |
803 | static struct class_compat *i2c_adapter_compat_class; | |
804 | #endif | |
805 | ||
9c1600ed DB |
806 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
807 | { | |
808 | struct i2c_devinfo *devinfo; | |
809 | ||
f18c41da | 810 | down_read(&__i2c_board_lock); |
9c1600ed DB |
811 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
812 | if (devinfo->busnum == adapter->nr | |
813 | && !i2c_new_device(adapter, | |
814 | &devinfo->board_info)) | |
09b8ce0a ZX |
815 | dev_err(&adapter->dev, |
816 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
817 | devinfo->board_info.addr); |
818 | } | |
f18c41da | 819 | up_read(&__i2c_board_lock); |
9c1600ed DB |
820 | } |
821 | ||
69b0089a JD |
822 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
823 | struct i2c_adapter *adap) | |
026526f5 | 824 | { |
4735c98f JD |
825 | /* Detect supported devices on that bus, and instantiate them */ |
826 | i2c_detect(adap, driver); | |
827 | ||
828 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 JD |
829 | if (driver->attach_adapter) { |
830 | /* We ignore the return code; if it fails, too bad */ | |
831 | driver->attach_adapter(adap); | |
832 | } | |
833 | return 0; | |
834 | } | |
835 | ||
69b0089a JD |
836 | static int __process_new_adapter(struct device_driver *d, void *data) |
837 | { | |
838 | return i2c_do_add_adapter(to_i2c_driver(d), data); | |
839 | } | |
840 | ||
6e13e641 | 841 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 842 | { |
d6703281 | 843 | int res = 0; |
1da177e4 | 844 | |
1d0b19c9 | 845 | /* Can't register until after driver model init */ |
35fc37f8 JD |
846 | if (unlikely(WARN_ON(!i2c_bus_type.p))) { |
847 | res = -EAGAIN; | |
848 | goto out_list; | |
849 | } | |
1d0b19c9 | 850 | |
194684e5 | 851 | rt_mutex_init(&adap->bus_lock); |
dafc50d1 | 852 | mutex_init(&adap->userspace_clients_lock); |
6629dcff | 853 | INIT_LIST_HEAD(&adap->userspace_clients); |
1da177e4 | 854 | |
8fcfef6e JD |
855 | /* Set default timeout to 1 second if not already set */ |
856 | if (adap->timeout == 0) | |
857 | adap->timeout = HZ; | |
858 | ||
27d9c183 | 859 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
860 | adap->dev.bus = &i2c_bus_type; |
861 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 JD |
862 | res = device_register(&adap->dev); |
863 | if (res) | |
864 | goto out_list; | |
1da177e4 | 865 | |
b6d7b3d1 JD |
866 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
867 | ||
2bb5095a JD |
868 | #ifdef CONFIG_I2C_COMPAT |
869 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
870 | adap->dev.parent); | |
871 | if (res) | |
872 | dev_warn(&adap->dev, | |
873 | "Failed to create compatibility class link\n"); | |
874 | #endif | |
875 | ||
729d6dd5 | 876 | /* create pre-declared device nodes */ |
6e13e641 DB |
877 | if (adap->nr < __i2c_first_dynamic_bus_num) |
878 | i2c_scan_static_board_info(adap); | |
879 | ||
4735c98f | 880 | /* Notify drivers */ |
35fc37f8 | 881 | mutex_lock(&core_lock); |
d6703281 | 882 | bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); |
caada32a | 883 | mutex_unlock(&core_lock); |
35fc37f8 JD |
884 | |
885 | return 0; | |
b119c6c9 | 886 | |
b119c6c9 | 887 | out_list: |
35fc37f8 | 888 | mutex_lock(&core_lock); |
b119c6c9 | 889 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
890 | mutex_unlock(&core_lock); |
891 | return res; | |
1da177e4 LT |
892 | } |
893 | ||
6e13e641 DB |
894 | /** |
895 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
896 | * @adapter: the adapter to add | |
d64f73be | 897 | * Context: can sleep |
6e13e641 DB |
898 | * |
899 | * This routine is used to declare an I2C adapter when its bus number | |
900 | * doesn't matter. Examples: for I2C adapters dynamically added by | |
901 | * USB links or PCI plugin cards. | |
902 | * | |
903 | * When this returns zero, a new bus number was allocated and stored | |
904 | * in adap->nr, and the specified adapter became available for clients. | |
905 | * Otherwise, a negative errno value is returned. | |
906 | */ | |
907 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
908 | { | |
909 | int id, res = 0; | |
910 | ||
911 | retry: | |
912 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
913 | return -ENOMEM; | |
914 | ||
caada32a | 915 | mutex_lock(&core_lock); |
6e13e641 DB |
916 | /* "above" here means "above or equal to", sigh */ |
917 | res = idr_get_new_above(&i2c_adapter_idr, adapter, | |
918 | __i2c_first_dynamic_bus_num, &id); | |
caada32a | 919 | mutex_unlock(&core_lock); |
6e13e641 DB |
920 | |
921 | if (res < 0) { | |
922 | if (res == -EAGAIN) | |
923 | goto retry; | |
924 | return res; | |
925 | } | |
926 | ||
927 | adapter->nr = id; | |
928 | return i2c_register_adapter(adapter); | |
929 | } | |
930 | EXPORT_SYMBOL(i2c_add_adapter); | |
931 | ||
932 | /** | |
933 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
934 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 935 | * Context: can sleep |
6e13e641 DB |
936 | * |
937 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
938 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
939 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
940 | * is used to properly configure I2C devices. |
941 | * | |
942 | * If no devices have pre-been declared for this bus, then be sure to | |
943 | * register the adapter before any dynamically allocated ones. Otherwise | |
944 | * the required bus ID may not be available. | |
945 | * | |
946 | * When this returns zero, the specified adapter became available for | |
947 | * clients using the bus number provided in adap->nr. Also, the table | |
948 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
949 | * and the appropriate driver model device nodes are created. Otherwise, a | |
950 | * negative errno value is returned. | |
951 | */ | |
952 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
953 | { | |
954 | int id; | |
955 | int status; | |
956 | ||
957 | if (adap->nr & ~MAX_ID_MASK) | |
958 | return -EINVAL; | |
959 | ||
960 | retry: | |
961 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
962 | return -ENOMEM; | |
963 | ||
caada32a | 964 | mutex_lock(&core_lock); |
6e13e641 DB |
965 | /* "above" here means "above or equal to", sigh; |
966 | * we need the "equal to" result to force the result | |
967 | */ | |
968 | status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id); | |
969 | if (status == 0 && id != adap->nr) { | |
970 | status = -EBUSY; | |
971 | idr_remove(&i2c_adapter_idr, id); | |
972 | } | |
caada32a | 973 | mutex_unlock(&core_lock); |
6e13e641 DB |
974 | if (status == -EAGAIN) |
975 | goto retry; | |
976 | ||
977 | if (status == 0) | |
978 | status = i2c_register_adapter(adap); | |
979 | return status; | |
980 | } | |
981 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
982 | ||
69b0089a JD |
983 | static int i2c_do_del_adapter(struct i2c_driver *driver, |
984 | struct i2c_adapter *adapter) | |
026526f5 | 985 | { |
4735c98f | 986 | struct i2c_client *client, *_n; |
026526f5 JD |
987 | int res; |
988 | ||
acec211c JD |
989 | /* Remove the devices we created ourselves as the result of hardware |
990 | * probing (using a driver's detect method) */ | |
4735c98f JD |
991 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
992 | if (client->adapter == adapter) { | |
993 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
994 | client->name, client->addr); | |
995 | list_del(&client->detected); | |
996 | i2c_unregister_device(client); | |
997 | } | |
998 | } | |
999 | ||
026526f5 JD |
1000 | if (!driver->detach_adapter) |
1001 | return 0; | |
1002 | res = driver->detach_adapter(adapter); | |
1003 | if (res) | |
1004 | dev_err(&adapter->dev, "detach_adapter failed (%d) " | |
1005 | "for driver [%s]\n", res, driver->driver.name); | |
1006 | return res; | |
1007 | } | |
1008 | ||
e549c2b5 JD |
1009 | static int __unregister_client(struct device *dev, void *dummy) |
1010 | { | |
1011 | struct i2c_client *client = i2c_verify_client(dev); | |
1012 | if (client) | |
1013 | i2c_unregister_device(client); | |
1014 | return 0; | |
1015 | } | |
1016 | ||
69b0089a JD |
1017 | static int __process_removed_adapter(struct device_driver *d, void *data) |
1018 | { | |
1019 | return i2c_do_del_adapter(to_i2c_driver(d), data); | |
1020 | } | |
1021 | ||
d64f73be DB |
1022 | /** |
1023 | * i2c_del_adapter - unregister I2C adapter | |
1024 | * @adap: the adapter being unregistered | |
1025 | * Context: can sleep | |
1026 | * | |
1027 | * This unregisters an I2C adapter which was previously registered | |
1028 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
1029 | */ | |
1da177e4 LT |
1030 | int i2c_del_adapter(struct i2c_adapter *adap) |
1031 | { | |
1da177e4 | 1032 | int res = 0; |
35fc37f8 | 1033 | struct i2c_adapter *found; |
bbd2d9c9 | 1034 | struct i2c_client *client, *next; |
1da177e4 LT |
1035 | |
1036 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
1037 | mutex_lock(&core_lock); |
1038 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
1039 | mutex_unlock(&core_lock); | |
1040 | if (found != adap) { | |
b6d7b3d1 JD |
1041 | pr_debug("i2c-core: attempting to delete unregistered " |
1042 | "adapter [%s]\n", adap->name); | |
35fc37f8 | 1043 | return -EINVAL; |
1da177e4 LT |
1044 | } |
1045 | ||
026526f5 | 1046 | /* Tell drivers about this removal */ |
35fc37f8 | 1047 | mutex_lock(&core_lock); |
026526f5 | 1048 | res = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 1049 | __process_removed_adapter); |
35fc37f8 | 1050 | mutex_unlock(&core_lock); |
026526f5 | 1051 | if (res) |
35fc37f8 | 1052 | return res; |
1da177e4 | 1053 | |
bbd2d9c9 | 1054 | /* Remove devices instantiated from sysfs */ |
dafc50d1 | 1055 | mutex_lock(&adap->userspace_clients_lock); |
6629dcff JD |
1056 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1057 | detected) { | |
1058 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, | |
1059 | client->addr); | |
1060 | list_del(&client->detected); | |
1061 | i2c_unregister_device(client); | |
bbd2d9c9 | 1062 | } |
dafc50d1 | 1063 | mutex_unlock(&adap->userspace_clients_lock); |
bbd2d9c9 | 1064 | |
e549c2b5 JD |
1065 | /* Detach any active clients. This can't fail, thus we do not |
1066 | checking the returned value. */ | |
1067 | res = device_for_each_child(&adap->dev, NULL, __unregister_client); | |
1da177e4 | 1068 | |
2bb5095a JD |
1069 | #ifdef CONFIG_I2C_COMPAT |
1070 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
1071 | adap->dev.parent); | |
1072 | #endif | |
1073 | ||
c5567521 TLSC |
1074 | /* device name is gone after device_unregister */ |
1075 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); | |
1076 | ||
1da177e4 LT |
1077 | /* clean up the sysfs representation */ |
1078 | init_completion(&adap->dev_released); | |
1da177e4 | 1079 | device_unregister(&adap->dev); |
1da177e4 LT |
1080 | |
1081 | /* wait for sysfs to drop all references */ | |
1082 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 1083 | |
6e13e641 | 1084 | /* free bus id */ |
35fc37f8 | 1085 | mutex_lock(&core_lock); |
1da177e4 | 1086 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 1087 | mutex_unlock(&core_lock); |
1da177e4 | 1088 | |
bd4bc3db JD |
1089 | /* Clear the device structure in case this adapter is ever going to be |
1090 | added again */ | |
1091 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
1092 | ||
35fc37f8 | 1093 | return 0; |
1da177e4 | 1094 | } |
c0564606 | 1095 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 LT |
1096 | |
1097 | ||
7b4fbc50 DB |
1098 | /* ------------------------------------------------------------------------- */ |
1099 | ||
69b0089a | 1100 | static int __process_new_driver(struct device *dev, void *data) |
7f101a97 | 1101 | { |
4f8cf824 JD |
1102 | if (dev->type != &i2c_adapter_type) |
1103 | return 0; | |
69b0089a | 1104 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
7f101a97 DY |
1105 | } |
1106 | ||
7b4fbc50 DB |
1107 | /* |
1108 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 1109 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
1110 | */ |
1111 | ||
de59cf9e | 1112 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 1113 | { |
7eebcb7c | 1114 | int res; |
1da177e4 | 1115 | |
1d0b19c9 DB |
1116 | /* Can't register until after driver model init */ |
1117 | if (unlikely(WARN_ON(!i2c_bus_type.p))) | |
1118 | return -EAGAIN; | |
1119 | ||
1da177e4 | 1120 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 1121 | driver->driver.owner = owner; |
1da177e4 | 1122 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 1123 | |
729d6dd5 | 1124 | /* When registration returns, the driver core |
6e13e641 DB |
1125 | * will have called probe() for all matching-but-unbound devices. |
1126 | */ | |
1da177e4 LT |
1127 | res = driver_register(&driver->driver); |
1128 | if (res) | |
7eebcb7c | 1129 | return res; |
438d6c2c | 1130 | |
35d8b2e6 | 1131 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 1132 | |
4735c98f JD |
1133 | INIT_LIST_HEAD(&driver->clients); |
1134 | /* Walk the adapters that are already present */ | |
35fc37f8 | 1135 | mutex_lock(&core_lock); |
69b0089a | 1136 | bus_for_each_dev(&i2c_bus_type, NULL, driver, __process_new_driver); |
7f101a97 | 1137 | mutex_unlock(&core_lock); |
35fc37f8 | 1138 | |
7f101a97 DY |
1139 | return 0; |
1140 | } | |
1141 | EXPORT_SYMBOL(i2c_register_driver); | |
1142 | ||
69b0089a | 1143 | static int __process_removed_driver(struct device *dev, void *data) |
7f101a97 | 1144 | { |
4f8cf824 JD |
1145 | if (dev->type != &i2c_adapter_type) |
1146 | return 0; | |
69b0089a | 1147 | return i2c_do_del_adapter(data, to_i2c_adapter(dev)); |
1da177e4 LT |
1148 | } |
1149 | ||
a1d9e6e4 DB |
1150 | /** |
1151 | * i2c_del_driver - unregister I2C driver | |
1152 | * @driver: the driver being unregistered | |
d64f73be | 1153 | * Context: can sleep |
a1d9e6e4 | 1154 | */ |
b3e82096 | 1155 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 1156 | { |
caada32a | 1157 | mutex_lock(&core_lock); |
69b0089a | 1158 | bus_for_each_dev(&i2c_bus_type, NULL, driver, __process_removed_driver); |
35fc37f8 | 1159 | mutex_unlock(&core_lock); |
1da177e4 LT |
1160 | |
1161 | driver_unregister(&driver->driver); | |
35d8b2e6 | 1162 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 1163 | } |
c0564606 | 1164 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 1165 | |
7b4fbc50 DB |
1166 | /* ------------------------------------------------------------------------- */ |
1167 | ||
e48d3319 JD |
1168 | /** |
1169 | * i2c_use_client - increments the reference count of the i2c client structure | |
1170 | * @client: the client being referenced | |
1171 | * | |
1172 | * Each live reference to a client should be refcounted. The driver model does | |
1173 | * that automatically as part of driver binding, so that most drivers don't | |
1174 | * need to do this explicitly: they hold a reference until they're unbound | |
1175 | * from the device. | |
1176 | * | |
1177 | * A pointer to the client with the incremented reference counter is returned. | |
1178 | */ | |
1179 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 1180 | { |
6ea438ec DB |
1181 | if (client && get_device(&client->dev)) |
1182 | return client; | |
1183 | return NULL; | |
1da177e4 | 1184 | } |
c0564606 | 1185 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 1186 | |
e48d3319 JD |
1187 | /** |
1188 | * i2c_release_client - release a use of the i2c client structure | |
1189 | * @client: the client being no longer referenced | |
1190 | * | |
1191 | * Must be called when a user of a client is finished with it. | |
1192 | */ | |
1193 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 1194 | { |
6ea438ec DB |
1195 | if (client) |
1196 | put_device(&client->dev); | |
1da177e4 | 1197 | } |
c0564606 | 1198 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 1199 | |
9b766b81 DB |
1200 | struct i2c_cmd_arg { |
1201 | unsigned cmd; | |
1202 | void *arg; | |
1203 | }; | |
1204 | ||
1205 | static int i2c_cmd(struct device *dev, void *_arg) | |
1206 | { | |
1207 | struct i2c_client *client = i2c_verify_client(dev); | |
1208 | struct i2c_cmd_arg *arg = _arg; | |
1209 | ||
1210 | if (client && client->driver && client->driver->command) | |
1211 | client->driver->command(client, arg->cmd, arg->arg); | |
1212 | return 0; | |
1213 | } | |
1214 | ||
1da177e4 LT |
1215 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
1216 | { | |
9b766b81 | 1217 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 1218 | |
9b766b81 DB |
1219 | cmd_arg.cmd = cmd; |
1220 | cmd_arg.arg = arg; | |
1221 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 1222 | } |
c0564606 | 1223 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
1224 | |
1225 | static int __init i2c_init(void) | |
1226 | { | |
1227 | int retval; | |
1228 | ||
1229 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
1230 | if (retval) |
1231 | return retval; | |
2bb5095a JD |
1232 | #ifdef CONFIG_I2C_COMPAT |
1233 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
1234 | if (!i2c_adapter_compat_class) { | |
1235 | retval = -ENOMEM; | |
1236 | goto bus_err; | |
1237 | } | |
1238 | #endif | |
e9f1373b DB |
1239 | retval = i2c_add_driver(&dummy_driver); |
1240 | if (retval) | |
2bb5095a | 1241 | goto class_err; |
e9f1373b DB |
1242 | return 0; |
1243 | ||
2bb5095a JD |
1244 | class_err: |
1245 | #ifdef CONFIG_I2C_COMPAT | |
1246 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 1247 | bus_err: |
2bb5095a | 1248 | #endif |
e9f1373b DB |
1249 | bus_unregister(&i2c_bus_type); |
1250 | return retval; | |
1da177e4 LT |
1251 | } |
1252 | ||
1253 | static void __exit i2c_exit(void) | |
1254 | { | |
e9f1373b | 1255 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
1256 | #ifdef CONFIG_I2C_COMPAT |
1257 | class_compat_unregister(i2c_adapter_compat_class); | |
1258 | #endif | |
1da177e4 LT |
1259 | bus_unregister(&i2c_bus_type); |
1260 | } | |
1261 | ||
a10f9e7c DB |
1262 | /* We must initialize early, because some subsystems register i2c drivers |
1263 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1264 | */ | |
1265 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1266 | module_exit(i2c_exit); |
1267 | ||
1268 | /* ---------------------------------------------------- | |
1269 | * the functional interface to the i2c busses. | |
1270 | * ---------------------------------------------------- | |
1271 | */ | |
1272 | ||
a1cdedac DB |
1273 | /** |
1274 | * i2c_transfer - execute a single or combined I2C message | |
1275 | * @adap: Handle to I2C bus | |
1276 | * @msgs: One or more messages to execute before STOP is issued to | |
1277 | * terminate the operation; each message begins with a START. | |
1278 | * @num: Number of messages to be executed. | |
1279 | * | |
1280 | * Returns negative errno, else the number of messages executed. | |
1281 | * | |
1282 | * Note that there is no requirement that each message be sent to | |
1283 | * the same slave address, although that is the most common model. | |
1284 | */ | |
09b8ce0a | 1285 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 1286 | { |
66b650f0 CW |
1287 | unsigned long orig_jiffies; |
1288 | int ret, try; | |
1da177e4 | 1289 | |
a1cdedac DB |
1290 | /* REVISIT the fault reporting model here is weak: |
1291 | * | |
1292 | * - When we get an error after receiving N bytes from a slave, | |
1293 | * there is no way to report "N". | |
1294 | * | |
1295 | * - When we get a NAK after transmitting N bytes to a slave, | |
1296 | * there is no way to report "N" ... or to let the master | |
1297 | * continue executing the rest of this combined message, if | |
1298 | * that's the appropriate response. | |
1299 | * | |
1300 | * - When for example "num" is two and we successfully complete | |
1301 | * the first message but get an error part way through the | |
1302 | * second, it's unclear whether that should be reported as | |
1303 | * one (discarding status on the second message) or errno | |
1304 | * (discarding status on the first one). | |
1305 | */ | |
1306 | ||
1da177e4 LT |
1307 | if (adap->algo->master_xfer) { |
1308 | #ifdef DEBUG | |
1309 | for (ret = 0; ret < num; ret++) { | |
1310 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
1311 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
1312 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
1313 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
1314 | } |
1315 | #endif | |
1316 | ||
cea443a8 | 1317 | if (in_atomic() || irqs_disabled()) { |
fe61e07e | 1318 | ret = i2c_trylock_adapter(adap); |
cea443a8 MR |
1319 | if (!ret) |
1320 | /* I2C activity is ongoing. */ | |
1321 | return -EAGAIN; | |
1322 | } else { | |
fe61e07e | 1323 | i2c_lock_adapter(adap); |
cea443a8 MR |
1324 | } |
1325 | ||
66b650f0 CW |
1326 | /* Retry automatically on arbitration loss */ |
1327 | orig_jiffies = jiffies; | |
1328 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
1329 | ret = adap->algo->master_xfer(adap, msgs, num); | |
1330 | if (ret != -EAGAIN) | |
1331 | break; | |
1332 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
1333 | break; | |
1334 | } | |
fe61e07e | 1335 | i2c_unlock_adapter(adap); |
1da177e4 LT |
1336 | |
1337 | return ret; | |
1338 | } else { | |
1339 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1340 | return -EOPNOTSUPP; |
1da177e4 LT |
1341 | } |
1342 | } | |
c0564606 | 1343 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1344 | |
a1cdedac DB |
1345 | /** |
1346 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1347 | * @client: Handle to slave device | |
1348 | * @buf: Data that will be written to the slave | |
0c43ea54 | 1349 | * @count: How many bytes to write, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1350 | * |
1351 | * Returns negative errno, or else the number of bytes written. | |
1352 | */ | |
7225acf4 | 1353 | int i2c_master_send(struct i2c_client *client, const char *buf, int count) |
1da177e4 LT |
1354 | { |
1355 | int ret; | |
7225acf4 | 1356 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1357 | struct i2c_msg msg; |
1358 | ||
815f55f2 JD |
1359 | msg.addr = client->addr; |
1360 | msg.flags = client->flags & I2C_M_TEN; | |
1361 | msg.len = count; | |
1362 | msg.buf = (char *)buf; | |
438d6c2c | 1363 | |
815f55f2 | 1364 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1365 | |
815f55f2 JD |
1366 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes |
1367 | transmitted, else error code. */ | |
1368 | return (ret == 1) ? count : ret; | |
1da177e4 | 1369 | } |
c0564606 | 1370 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1371 | |
a1cdedac DB |
1372 | /** |
1373 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1374 | * @client: Handle to slave device | |
1375 | * @buf: Where to store data read from slave | |
0c43ea54 | 1376 | * @count: How many bytes to read, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1377 | * |
1378 | * Returns negative errno, or else the number of bytes read. | |
1379 | */ | |
7225acf4 | 1380 | int i2c_master_recv(struct i2c_client *client, char *buf, int count) |
1da177e4 | 1381 | { |
7225acf4 | 1382 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1383 | struct i2c_msg msg; |
1384 | int ret; | |
815f55f2 JD |
1385 | |
1386 | msg.addr = client->addr; | |
1387 | msg.flags = client->flags & I2C_M_TEN; | |
1388 | msg.flags |= I2C_M_RD; | |
1389 | msg.len = count; | |
1390 | msg.buf = buf; | |
1391 | ||
1392 | ret = i2c_transfer(adap, &msg, 1); | |
1393 | ||
1394 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1395 | transmitted, else error code. */ | |
1396 | return (ret == 1) ? count : ret; | |
1da177e4 | 1397 | } |
c0564606 | 1398 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1399 | |
1da177e4 LT |
1400 | /* ---------------------------------------------------- |
1401 | * the i2c address scanning function | |
1402 | * Will not work for 10-bit addresses! | |
1403 | * ---------------------------------------------------- | |
1404 | */ | |
1da177e4 | 1405 | |
63e4e802 JD |
1406 | /* |
1407 | * Legacy default probe function, mostly relevant for SMBus. The default | |
1408 | * probe method is a quick write, but it is known to corrupt the 24RF08 | |
1409 | * EEPROMs due to a state machine bug, and could also irreversibly | |
1410 | * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, | |
1411 | * we use a short byte read instead. Also, some bus drivers don't implement | |
1412 | * quick write, so we fallback to a byte read in that case too. | |
1413 | * On x86, there is another special case for FSC hardware monitoring chips, | |
1414 | * which want regular byte reads (address 0x73.) Fortunately, these are the | |
1415 | * only known chips using this I2C address on PC hardware. | |
1416 | * Returns 1 if probe succeeded, 0 if not. | |
1417 | */ | |
1418 | static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) | |
1419 | { | |
1420 | int err; | |
1421 | union i2c_smbus_data dummy; | |
1422 | ||
1423 | #ifdef CONFIG_X86 | |
1424 | if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) | |
1425 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) | |
1426 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1427 | I2C_SMBUS_BYTE_DATA, &dummy); | |
1428 | else | |
1429 | #endif | |
8031d79b JD |
1430 | if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) |
1431 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) | |
63e4e802 JD |
1432 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, |
1433 | I2C_SMBUS_QUICK, NULL); | |
8031d79b JD |
1434 | else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) |
1435 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1436 | I2C_SMBUS_BYTE, &dummy); | |
1437 | else { | |
1438 | dev_warn(&adap->dev, "No suitable probing method supported\n"); | |
1439 | err = -EOPNOTSUPP; | |
1440 | } | |
63e4e802 JD |
1441 | |
1442 | return err >= 0; | |
1443 | } | |
1444 | ||
ccfbbd08 | 1445 | static int i2c_detect_address(struct i2c_client *temp_client, |
4735c98f JD |
1446 | struct i2c_driver *driver) |
1447 | { | |
1448 | struct i2c_board_info info; | |
1449 | struct i2c_adapter *adapter = temp_client->adapter; | |
1450 | int addr = temp_client->addr; | |
1451 | int err; | |
1452 | ||
1453 | /* Make sure the address is valid */ | |
656b8761 JD |
1454 | err = i2c_check_addr_validity(addr); |
1455 | if (err) { | |
4735c98f JD |
1456 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
1457 | addr); | |
656b8761 | 1458 | return err; |
4735c98f JD |
1459 | } |
1460 | ||
1461 | /* Skip if already in use */ | |
3b5f794b | 1462 | if (i2c_check_addr_busy(adapter, addr)) |
4735c98f JD |
1463 | return 0; |
1464 | ||
ccfbbd08 | 1465 | /* Make sure there is something at this address */ |
63e4e802 JD |
1466 | if (!i2c_default_probe(adapter, addr)) |
1467 | return 0; | |
4735c98f JD |
1468 | |
1469 | /* Finally call the custom detection function */ | |
1470 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
1471 | info.addr = addr; | |
310ec792 | 1472 | err = driver->detect(temp_client, &info); |
4735c98f JD |
1473 | if (err) { |
1474 | /* -ENODEV is returned if the detection fails. We catch it | |
1475 | here as this isn't an error. */ | |
1476 | return err == -ENODEV ? 0 : err; | |
1477 | } | |
1478 | ||
1479 | /* Consistency check */ | |
1480 | if (info.type[0] == '\0') { | |
1481 | dev_err(&adapter->dev, "%s detection function provided " | |
1482 | "no name for 0x%x\n", driver->driver.name, | |
1483 | addr); | |
1484 | } else { | |
1485 | struct i2c_client *client; | |
1486 | ||
1487 | /* Detection succeeded, instantiate the device */ | |
1488 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", | |
1489 | info.type, info.addr); | |
1490 | client = i2c_new_device(adapter, &info); | |
1491 | if (client) | |
1492 | list_add_tail(&client->detected, &driver->clients); | |
1493 | else | |
1494 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
1495 | info.type, info.addr); | |
1496 | } | |
1497 | return 0; | |
1498 | } | |
1499 | ||
1500 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
1501 | { | |
c3813d6a | 1502 | const unsigned short *address_list; |
4735c98f JD |
1503 | struct i2c_client *temp_client; |
1504 | int i, err = 0; | |
1505 | int adap_id = i2c_adapter_id(adapter); | |
1506 | ||
c3813d6a JD |
1507 | address_list = driver->address_list; |
1508 | if (!driver->detect || !address_list) | |
4735c98f JD |
1509 | return 0; |
1510 | ||
51b54ba9 JD |
1511 | /* Stop here if the classes do not match */ |
1512 | if (!(adapter->class & driver->class)) | |
1513 | return 0; | |
1514 | ||
4735c98f JD |
1515 | /* Set up a temporary client to help detect callback */ |
1516 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
1517 | if (!temp_client) | |
1518 | return -ENOMEM; | |
1519 | temp_client->adapter = adapter; | |
1520 | ||
c3813d6a | 1521 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
4735c98f | 1522 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
c3813d6a JD |
1523 | "addr 0x%02x\n", adap_id, address_list[i]); |
1524 | temp_client->addr = address_list[i]; | |
ccfbbd08 | 1525 | err = i2c_detect_address(temp_client, driver); |
51b54ba9 JD |
1526 | if (unlikely(err)) |
1527 | break; | |
4735c98f JD |
1528 | } |
1529 | ||
4735c98f JD |
1530 | kfree(temp_client); |
1531 | return err; | |
1532 | } | |
1533 | ||
d44f19d5 JD |
1534 | int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) |
1535 | { | |
1536 | return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1537 | I2C_SMBUS_QUICK, NULL) >= 0; | |
1538 | } | |
1539 | EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); | |
1540 | ||
12b5053a JD |
1541 | struct i2c_client * |
1542 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1543 | struct i2c_board_info *info, | |
9a94241a JD |
1544 | unsigned short const *addr_list, |
1545 | int (*probe)(struct i2c_adapter *, unsigned short addr)) | |
12b5053a JD |
1546 | { |
1547 | int i; | |
1548 | ||
8031d79b | 1549 | if (!probe) |
9a94241a | 1550 | probe = i2c_default_probe; |
12b5053a | 1551 | |
12b5053a JD |
1552 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1553 | /* Check address validity */ | |
656b8761 | 1554 | if (i2c_check_addr_validity(addr_list[i]) < 0) { |
12b5053a JD |
1555 | dev_warn(&adap->dev, "Invalid 7-bit address " |
1556 | "0x%02x\n", addr_list[i]); | |
1557 | continue; | |
1558 | } | |
1559 | ||
1560 | /* Check address availability */ | |
3b5f794b | 1561 | if (i2c_check_addr_busy(adap, addr_list[i])) { |
12b5053a JD |
1562 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1563 | "use, not probing\n", addr_list[i]); | |
1564 | continue; | |
1565 | } | |
1566 | ||
63e4e802 | 1567 | /* Test address responsiveness */ |
9a94241a | 1568 | if (probe(adap, addr_list[i])) |
63e4e802 | 1569 | break; |
12b5053a | 1570 | } |
12b5053a JD |
1571 | |
1572 | if (addr_list[i] == I2C_CLIENT_END) { | |
1573 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1574 | return NULL; | |
1575 | } | |
1576 | ||
1577 | info->addr = addr_list[i]; | |
1578 | return i2c_new_device(adap, info); | |
1579 | } | |
1580 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
1581 | ||
7225acf4 | 1582 | struct i2c_adapter *i2c_get_adapter(int id) |
1da177e4 | 1583 | { |
1da177e4 | 1584 | struct i2c_adapter *adapter; |
438d6c2c | 1585 | |
caada32a | 1586 | mutex_lock(&core_lock); |
1cf92b45 | 1587 | adapter = idr_find(&i2c_adapter_idr, id); |
a0920e10 MH |
1588 | if (adapter && !try_module_get(adapter->owner)) |
1589 | adapter = NULL; | |
1590 | ||
caada32a | 1591 | mutex_unlock(&core_lock); |
a0920e10 | 1592 | return adapter; |
1da177e4 | 1593 | } |
c0564606 | 1594 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
1595 | |
1596 | void i2c_put_adapter(struct i2c_adapter *adap) | |
1597 | { | |
1598 | module_put(adap->owner); | |
1599 | } | |
c0564606 | 1600 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
1601 | |
1602 | /* The SMBus parts */ | |
1603 | ||
438d6c2c | 1604 | #define POLY (0x1070U << 3) |
09b8ce0a | 1605 | static u8 crc8(u16 data) |
1da177e4 LT |
1606 | { |
1607 | int i; | |
438d6c2c | 1608 | |
7225acf4 | 1609 | for (i = 0; i < 8; i++) { |
438d6c2c | 1610 | if (data & 0x8000) |
1da177e4 LT |
1611 | data = data ^ POLY; |
1612 | data = data << 1; | |
1613 | } | |
1614 | return (u8)(data >> 8); | |
1615 | } | |
1616 | ||
421ef47b JD |
1617 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
1618 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
1619 | { |
1620 | int i; | |
1621 | ||
7225acf4 | 1622 | for (i = 0; i < count; i++) |
421ef47b | 1623 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
1624 | return crc; |
1625 | } | |
1626 | ||
421ef47b JD |
1627 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
1628 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 1629 | { |
421ef47b JD |
1630 | /* The address will be sent first */ |
1631 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
1632 | pec = i2c_smbus_pec(pec, &addr, 1); | |
1633 | ||
1634 | /* The data buffer follows */ | |
1635 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
1636 | } |
1637 | ||
421ef47b JD |
1638 | /* Used for write only transactions */ |
1639 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 1640 | { |
421ef47b JD |
1641 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
1642 | msg->len++; | |
1da177e4 LT |
1643 | } |
1644 | ||
421ef47b JD |
1645 | /* Return <0 on CRC error |
1646 | If there was a write before this read (most cases) we need to take the | |
1647 | partial CRC from the write part into account. | |
1648 | Note that this function does modify the message (we need to decrease the | |
1649 | message length to hide the CRC byte from the caller). */ | |
1650 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 1651 | { |
421ef47b JD |
1652 | u8 rpec = msg->buf[--msg->len]; |
1653 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 1654 | |
1da177e4 LT |
1655 | if (rpec != cpec) { |
1656 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
1657 | rpec, cpec); | |
24a5bb7b | 1658 | return -EBADMSG; |
1da177e4 | 1659 | } |
438d6c2c | 1660 | return 0; |
1da177e4 LT |
1661 | } |
1662 | ||
a1cdedac DB |
1663 | /** |
1664 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
1665 | * @client: Handle to slave device | |
1666 | * | |
1667 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
1668 | * else the byte received from the device. | |
1669 | */ | |
1da177e4 LT |
1670 | s32 i2c_smbus_read_byte(struct i2c_client *client) |
1671 | { | |
1672 | union i2c_smbus_data data; | |
24a5bb7b DB |
1673 | int status; |
1674 | ||
1675 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1676 | I2C_SMBUS_READ, 0, | |
1677 | I2C_SMBUS_BYTE, &data); | |
1678 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1679 | } |
c0564606 | 1680 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 1681 | |
a1cdedac DB |
1682 | /** |
1683 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
1684 | * @client: Handle to slave device | |
1685 | * @value: Byte to be sent | |
1686 | * | |
1687 | * This executes the SMBus "send byte" protocol, returning negative errno | |
1688 | * else zero on success. | |
1689 | */ | |
1da177e4 LT |
1690 | s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) |
1691 | { | |
7225acf4 | 1692 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
421ef47b | 1693 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 1694 | } |
c0564606 | 1695 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 1696 | |
a1cdedac DB |
1697 | /** |
1698 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
1699 | * @client: Handle to slave device | |
1700 | * @command: Byte interpreted by slave | |
1701 | * | |
1702 | * This executes the SMBus "read byte" protocol, returning negative errno | |
1703 | * else a data byte received from the device. | |
1704 | */ | |
1da177e4 LT |
1705 | s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) |
1706 | { | |
1707 | union i2c_smbus_data data; | |
24a5bb7b DB |
1708 | int status; |
1709 | ||
1710 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1711 | I2C_SMBUS_READ, command, | |
1712 | I2C_SMBUS_BYTE_DATA, &data); | |
1713 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1714 | } |
c0564606 | 1715 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 1716 | |
a1cdedac DB |
1717 | /** |
1718 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
1719 | * @client: Handle to slave device | |
1720 | * @command: Byte interpreted by slave | |
1721 | * @value: Byte being written | |
1722 | * | |
1723 | * This executes the SMBus "write byte" protocol, returning negative errno | |
1724 | * else zero on success. | |
1725 | */ | |
1da177e4 LT |
1726 | s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) |
1727 | { | |
1728 | union i2c_smbus_data data; | |
1729 | data.byte = value; | |
7225acf4 FH |
1730 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1731 | I2C_SMBUS_WRITE, command, | |
1732 | I2C_SMBUS_BYTE_DATA, &data); | |
1da177e4 | 1733 | } |
c0564606 | 1734 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 1735 | |
a1cdedac DB |
1736 | /** |
1737 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
1738 | * @client: Handle to slave device | |
1739 | * @command: Byte interpreted by slave | |
1740 | * | |
1741 | * This executes the SMBus "read word" protocol, returning negative errno | |
1742 | * else a 16-bit unsigned "word" received from the device. | |
1743 | */ | |
1da177e4 LT |
1744 | s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) |
1745 | { | |
1746 | union i2c_smbus_data data; | |
24a5bb7b DB |
1747 | int status; |
1748 | ||
1749 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1750 | I2C_SMBUS_READ, command, | |
1751 | I2C_SMBUS_WORD_DATA, &data); | |
1752 | return (status < 0) ? status : data.word; | |
1da177e4 | 1753 | } |
c0564606 | 1754 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 1755 | |
a1cdedac DB |
1756 | /** |
1757 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
1758 | * @client: Handle to slave device | |
1759 | * @command: Byte interpreted by slave | |
1760 | * @value: 16-bit "word" being written | |
1761 | * | |
1762 | * This executes the SMBus "write word" protocol, returning negative errno | |
1763 | * else zero on success. | |
1764 | */ | |
1da177e4 LT |
1765 | s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) |
1766 | { | |
1767 | union i2c_smbus_data data; | |
1768 | data.word = value; | |
7225acf4 FH |
1769 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1770 | I2C_SMBUS_WRITE, command, | |
1771 | I2C_SMBUS_WORD_DATA, &data); | |
1da177e4 | 1772 | } |
c0564606 | 1773 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 1774 | |
596c88f4 PM |
1775 | /** |
1776 | * i2c_smbus_process_call - SMBus "process call" protocol | |
1777 | * @client: Handle to slave device | |
1778 | * @command: Byte interpreted by slave | |
1779 | * @value: 16-bit "word" being written | |
1780 | * | |
1781 | * This executes the SMBus "process call" protocol, returning negative errno | |
1782 | * else a 16-bit unsigned "word" received from the device. | |
1783 | */ | |
1784 | s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value) | |
1785 | { | |
1786 | union i2c_smbus_data data; | |
1787 | int status; | |
1788 | data.word = value; | |
1789 | ||
1790 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1791 | I2C_SMBUS_WRITE, command, | |
1792 | I2C_SMBUS_PROC_CALL, &data); | |
1793 | return (status < 0) ? status : data.word; | |
1794 | } | |
1795 | EXPORT_SYMBOL(i2c_smbus_process_call); | |
1796 | ||
a64ec07d | 1797 | /** |
a1cdedac | 1798 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 1799 | * @client: Handle to slave device |
a1cdedac | 1800 | * @command: Byte interpreted by slave |
a64ec07d DB |
1801 | * @values: Byte array into which data will be read; big enough to hold |
1802 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
1803 | * | |
a1cdedac DB |
1804 | * This executes the SMBus "block read" protocol, returning negative errno |
1805 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
1806 | * |
1807 | * Note that using this function requires that the client's adapter support | |
1808 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
1809 | * support this; its emulation through I2C messaging relies on a specific | |
1810 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
1811 | */ | |
b86a1bc8 JD |
1812 | s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, |
1813 | u8 *values) | |
1814 | { | |
1815 | union i2c_smbus_data data; | |
24a5bb7b | 1816 | int status; |
b86a1bc8 | 1817 | |
24a5bb7b DB |
1818 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1819 | I2C_SMBUS_READ, command, | |
1820 | I2C_SMBUS_BLOCK_DATA, &data); | |
1821 | if (status) | |
1822 | return status; | |
b86a1bc8 JD |
1823 | |
1824 | memcpy(values, &data.block[1], data.block[0]); | |
1825 | return data.block[0]; | |
1826 | } | |
1827 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
1828 | ||
a1cdedac DB |
1829 | /** |
1830 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
1831 | * @client: Handle to slave device | |
1832 | * @command: Byte interpreted by slave | |
1833 | * @length: Size of data block; SMBus allows at most 32 bytes | |
1834 | * @values: Byte array which will be written. | |
1835 | * | |
1836 | * This executes the SMBus "block write" protocol, returning negative errno | |
1837 | * else zero on success. | |
1838 | */ | |
1da177e4 | 1839 | s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1840 | u8 length, const u8 *values) |
1da177e4 LT |
1841 | { |
1842 | union i2c_smbus_data data; | |
7656032b | 1843 | |
1da177e4 LT |
1844 | if (length > I2C_SMBUS_BLOCK_MAX) |
1845 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 1846 | data.block[0] = length; |
7656032b | 1847 | memcpy(&data.block[1], values, length); |
7225acf4 FH |
1848 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1849 | I2C_SMBUS_WRITE, command, | |
1850 | I2C_SMBUS_BLOCK_DATA, &data); | |
1da177e4 | 1851 | } |
c0564606 | 1852 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
1853 | |
1854 | /* Returns the number of read bytes */ | |
4b2643d7 JD |
1855 | s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, |
1856 | u8 length, u8 *values) | |
1da177e4 LT |
1857 | { |
1858 | union i2c_smbus_data data; | |
24a5bb7b | 1859 | int status; |
7656032b | 1860 | |
4b2643d7 JD |
1861 | if (length > I2C_SMBUS_BLOCK_MAX) |
1862 | length = I2C_SMBUS_BLOCK_MAX; | |
1863 | data.block[0] = length; | |
24a5bb7b DB |
1864 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1865 | I2C_SMBUS_READ, command, | |
1866 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1867 | if (status < 0) | |
1868 | return status; | |
7656032b JD |
1869 | |
1870 | memcpy(values, &data.block[1], data.block[0]); | |
1871 | return data.block[0]; | |
1da177e4 | 1872 | } |
c0564606 | 1873 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 1874 | |
21bbd691 | 1875 | s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1876 | u8 length, const u8 *values) |
21bbd691 JD |
1877 | { |
1878 | union i2c_smbus_data data; | |
1879 | ||
1880 | if (length > I2C_SMBUS_BLOCK_MAX) | |
1881 | length = I2C_SMBUS_BLOCK_MAX; | |
1882 | data.block[0] = length; | |
1883 | memcpy(data.block + 1, values, length); | |
1884 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1885 | I2C_SMBUS_WRITE, command, | |
1886 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1887 | } | |
c0564606 | 1888 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 1889 | |
438d6c2c | 1890 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 1891 | No checking of parameters is done! */ |
7225acf4 FH |
1892 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, |
1893 | unsigned short flags, | |
1894 | char read_write, u8 command, int size, | |
1895 | union i2c_smbus_data *data) | |
1da177e4 LT |
1896 | { |
1897 | /* So we need to generate a series of msgs. In the case of writing, we | |
1898 | need to use only one message; when reading, we need two. We initialize | |
1899 | most things with sane defaults, to keep the code below somewhat | |
1900 | simpler. */ | |
5c50d188 HI |
1901 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
1902 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
7225acf4 | 1903 | int num = read_write == I2C_SMBUS_READ ? 2 : 1; |
438d6c2c | 1904 | struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 }, |
1da177e4 LT |
1905 | { addr, flags | I2C_M_RD, 0, msgbuf1 } |
1906 | }; | |
1907 | int i; | |
421ef47b | 1908 | u8 partial_pec = 0; |
24a5bb7b | 1909 | int status; |
1da177e4 LT |
1910 | |
1911 | msgbuf0[0] = command; | |
7225acf4 | 1912 | switch (size) { |
1da177e4 LT |
1913 | case I2C_SMBUS_QUICK: |
1914 | msg[0].len = 0; | |
1915 | /* Special case: The read/write field is used as data */ | |
f29d2e02 RK |
1916 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
1917 | I2C_M_RD : 0); | |
1da177e4 LT |
1918 | num = 1; |
1919 | break; | |
1920 | case I2C_SMBUS_BYTE: | |
1921 | if (read_write == I2C_SMBUS_READ) { | |
1922 | /* Special case: only a read! */ | |
1923 | msg[0].flags = I2C_M_RD | flags; | |
1924 | num = 1; | |
1925 | } | |
1926 | break; | |
1927 | case I2C_SMBUS_BYTE_DATA: | |
1928 | if (read_write == I2C_SMBUS_READ) | |
1929 | msg[1].len = 1; | |
1930 | else { | |
1931 | msg[0].len = 2; | |
1932 | msgbuf0[1] = data->byte; | |
1933 | } | |
1934 | break; | |
1935 | case I2C_SMBUS_WORD_DATA: | |
1936 | if (read_write == I2C_SMBUS_READ) | |
1937 | msg[1].len = 2; | |
1938 | else { | |
7225acf4 | 1939 | msg[0].len = 3; |
1da177e4 | 1940 | msgbuf0[1] = data->word & 0xff; |
7eff82c8 | 1941 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1942 | } |
1943 | break; | |
1944 | case I2C_SMBUS_PROC_CALL: | |
1945 | num = 2; /* Special case */ | |
1946 | read_write = I2C_SMBUS_READ; | |
1947 | msg[0].len = 3; | |
1948 | msg[1].len = 2; | |
1949 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1950 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1951 | break; |
1952 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 1953 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
1954 | msg[1].flags |= I2C_M_RECV_LEN; |
1955 | msg[1].len = 1; /* block length will be added by | |
1956 | the underlying bus driver */ | |
1da177e4 LT |
1957 | } else { |
1958 | msg[0].len = data->block[0] + 2; | |
1959 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
1960 | dev_err(&adapter->dev, |
1961 | "Invalid block write size %d\n", | |
1962 | data->block[0]); | |
1963 | return -EINVAL; | |
1da177e4 | 1964 | } |
5c50d188 | 1965 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
1966 | msgbuf0[i] = data->block[i-1]; |
1967 | } | |
1968 | break; | |
1969 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
1970 | num = 2; /* Another special case */ |
1971 | read_write = I2C_SMBUS_READ; | |
1972 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
1973 | dev_err(&adapter->dev, |
1974 | "Invalid block write size %d\n", | |
209d27c3 | 1975 | data->block[0]); |
24a5bb7b | 1976 | return -EINVAL; |
209d27c3 JD |
1977 | } |
1978 | msg[0].len = data->block[0] + 2; | |
1979 | for (i = 1; i < msg[0].len; i++) | |
1980 | msgbuf0[i] = data->block[i-1]; | |
1981 | msg[1].flags |= I2C_M_RECV_LEN; | |
1982 | msg[1].len = 1; /* block length will be added by | |
1983 | the underlying bus driver */ | |
1984 | break; | |
1da177e4 LT |
1985 | case I2C_SMBUS_I2C_BLOCK_DATA: |
1986 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 1987 | msg[1].len = data->block[0]; |
1da177e4 LT |
1988 | } else { |
1989 | msg[0].len = data->block[0] + 1; | |
30dac746 | 1990 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
1991 | dev_err(&adapter->dev, |
1992 | "Invalid block write size %d\n", | |
1993 | data->block[0]); | |
1994 | return -EINVAL; | |
1da177e4 LT |
1995 | } |
1996 | for (i = 1; i <= data->block[0]; i++) | |
1997 | msgbuf0[i] = data->block[i]; | |
1998 | } | |
1999 | break; | |
2000 | default: | |
24a5bb7b DB |
2001 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
2002 | return -EOPNOTSUPP; | |
1da177e4 LT |
2003 | } |
2004 | ||
421ef47b JD |
2005 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
2006 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
2007 | if (i) { | |
2008 | /* Compute PEC if first message is a write */ | |
2009 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 2010 | if (num == 1) /* Write only */ |
421ef47b JD |
2011 | i2c_smbus_add_pec(&msg[0]); |
2012 | else /* Write followed by read */ | |
2013 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
2014 | } | |
2015 | /* Ask for PEC if last message is a read */ | |
2016 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 2017 | msg[num-1].len++; |
421ef47b JD |
2018 | } |
2019 | ||
24a5bb7b DB |
2020 | status = i2c_transfer(adapter, msg, num); |
2021 | if (status < 0) | |
2022 | return status; | |
1da177e4 | 2023 | |
421ef47b JD |
2024 | /* Check PEC if last message is a read */ |
2025 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
2026 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
2027 | if (status < 0) | |
2028 | return status; | |
421ef47b JD |
2029 | } |
2030 | ||
1da177e4 | 2031 | if (read_write == I2C_SMBUS_READ) |
7225acf4 FH |
2032 | switch (size) { |
2033 | case I2C_SMBUS_BYTE: | |
2034 | data->byte = msgbuf0[0]; | |
2035 | break; | |
2036 | case I2C_SMBUS_BYTE_DATA: | |
2037 | data->byte = msgbuf1[0]; | |
2038 | break; | |
2039 | case I2C_SMBUS_WORD_DATA: | |
2040 | case I2C_SMBUS_PROC_CALL: | |
2041 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
2042 | break; | |
2043 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
2044 | for (i = 0; i < data->block[0]; i++) | |
2045 | data->block[i+1] = msgbuf1[i]; | |
2046 | break; | |
2047 | case I2C_SMBUS_BLOCK_DATA: | |
2048 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
2049 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
2050 | data->block[i] = msgbuf1[i]; | |
2051 | break; | |
1da177e4 LT |
2052 | } |
2053 | return 0; | |
2054 | } | |
2055 | ||
a1cdedac DB |
2056 | /** |
2057 | * i2c_smbus_xfer - execute SMBus protocol operations | |
2058 | * @adapter: Handle to I2C bus | |
2059 | * @addr: Address of SMBus slave on that bus | |
2060 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
2061 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
2062 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
2063 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
2064 | * @data: Data to be read or written | |
2065 | * | |
2066 | * This executes an SMBus protocol operation, and returns a negative | |
2067 | * errno code else zero on success. | |
2068 | */ | |
09b8ce0a | 2069 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
a1cdedac | 2070 | char read_write, u8 command, int protocol, |
09b8ce0a | 2071 | union i2c_smbus_data *data) |
1da177e4 | 2072 | { |
66b650f0 CW |
2073 | unsigned long orig_jiffies; |
2074 | int try; | |
1da177e4 | 2075 | s32 res; |
1da177e4 LT |
2076 | |
2077 | flags &= I2C_M_TEN | I2C_CLIENT_PEC; | |
1da177e4 LT |
2078 | |
2079 | if (adapter->algo->smbus_xfer) { | |
fe61e07e | 2080 | i2c_lock_adapter(adapter); |
66b650f0 CW |
2081 | |
2082 | /* Retry automatically on arbitration loss */ | |
2083 | orig_jiffies = jiffies; | |
2084 | for (res = 0, try = 0; try <= adapter->retries; try++) { | |
2085 | res = adapter->algo->smbus_xfer(adapter, addr, flags, | |
2086 | read_write, command, | |
2087 | protocol, data); | |
2088 | if (res != -EAGAIN) | |
2089 | break; | |
2090 | if (time_after(jiffies, | |
2091 | orig_jiffies + adapter->timeout)) | |
2092 | break; | |
2093 | } | |
fe61e07e | 2094 | i2c_unlock_adapter(adapter); |
1da177e4 | 2095 | } else |
7225acf4 | 2096 | res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, |
a1cdedac | 2097 | command, protocol, data); |
1da177e4 | 2098 | |
1da177e4 LT |
2099 | return res; |
2100 | } | |
1da177e4 | 2101 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
2102 | |
2103 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
2104 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
2105 | MODULE_LICENSE("GPL"); |