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 | |
5694f8a8 JD |
17 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, |
18 | MA 02110-1301 USA. */ | |
1da177e4 LT |
19 | /* ------------------------------------------------------------------------- */ |
20 | ||
96de0e25 | 21 | /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>. |
1da177e4 | 22 | All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl> |
421ef47b | 23 | SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and |
0826374b ML |
24 | Jean Delvare <khali@linux-fr.org> |
25 | Mux support by Rodolfo Giometti <giometti@enneenne.com> and | |
26 | Michael Lawnick <michael.lawnick.ext@nsn.com> */ | |
1da177e4 | 27 | |
1da177e4 LT |
28 | #include <linux/module.h> |
29 | #include <linux/kernel.h> | |
5f9296ba | 30 | #include <linux/delay.h> |
1da177e4 | 31 | #include <linux/errno.h> |
5f9296ba | 32 | #include <linux/gpio.h> |
1da177e4 LT |
33 | #include <linux/slab.h> |
34 | #include <linux/i2c.h> | |
35 | #include <linux/init.h> | |
36 | #include <linux/idr.h> | |
b3585e4f | 37 | #include <linux/mutex.h> |
959e85f7 | 38 | #include <linux/of_device.h> |
b8d6f45b | 39 | #include <linux/completion.h> |
cea443a8 MR |
40 | #include <linux/hardirq.h> |
41 | #include <linux/irqflags.h> | |
f18c41da | 42 | #include <linux/rwsem.h> |
6de468ae | 43 | #include <linux/pm_runtime.h> |
907ddf89 | 44 | #include <linux/acpi.h> |
1da177e4 LT |
45 | #include <asm/uaccess.h> |
46 | ||
9c1600ed DB |
47 | #include "i2c-core.h" |
48 | ||
1da177e4 | 49 | |
6629dcff | 50 | /* core_lock protects i2c_adapter_idr, and guarantees |
35fc37f8 | 51 | that device detection, deletion of detected devices, and attach_adapter |
19baba4c | 52 | calls are serialized */ |
caada32a | 53 | static DEFINE_MUTEX(core_lock); |
1da177e4 LT |
54 | static DEFINE_IDR(i2c_adapter_idr); |
55 | ||
4f8cf824 | 56 | static struct device_type i2c_client_type; |
4735c98f | 57 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
f37dd80a DB |
58 | |
59 | /* ------------------------------------------------------------------------- */ | |
60 | ||
d2653e92 JD |
61 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
62 | const struct i2c_client *client) | |
63 | { | |
64 | while (id->name[0]) { | |
65 | if (strcmp(client->name, id->name) == 0) | |
66 | return id; | |
67 | id++; | |
68 | } | |
69 | return NULL; | |
70 | } | |
71 | ||
1da177e4 LT |
72 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
73 | { | |
51298d12 JD |
74 | struct i2c_client *client = i2c_verify_client(dev); |
75 | struct i2c_driver *driver; | |
76 | ||
77 | if (!client) | |
78 | return 0; | |
7b4fbc50 | 79 | |
959e85f7 GL |
80 | /* Attempt an OF style match */ |
81 | if (of_driver_match_device(dev, drv)) | |
82 | return 1; | |
83 | ||
907ddf89 MW |
84 | /* Then ACPI style match */ |
85 | if (acpi_driver_match_device(dev, drv)) | |
86 | return 1; | |
87 | ||
51298d12 | 88 | driver = to_i2c_driver(drv); |
d2653e92 JD |
89 | /* match on an id table if there is one */ |
90 | if (driver->id_table) | |
91 | return i2c_match_id(driver->id_table, client) != NULL; | |
92 | ||
eb8a7908 | 93 | return 0; |
1da177e4 LT |
94 | } |
95 | ||
7b4fbc50 DB |
96 | |
97 | /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ | |
7eff2e7a | 98 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 DB |
99 | { |
100 | struct i2c_client *client = to_i2c_client(dev); | |
7b4fbc50 | 101 | |
eb8a7908 JD |
102 | if (add_uevent_var(env, "MODALIAS=%s%s", |
103 | I2C_MODULE_PREFIX, client->name)) | |
104 | return -ENOMEM; | |
7b4fbc50 DB |
105 | dev_dbg(dev, "uevent\n"); |
106 | return 0; | |
107 | } | |
108 | ||
5f9296ba VK |
109 | /* i2c bus recovery routines */ |
110 | static int get_scl_gpio_value(struct i2c_adapter *adap) | |
111 | { | |
112 | return gpio_get_value(adap->bus_recovery_info->scl_gpio); | |
113 | } | |
114 | ||
115 | static void set_scl_gpio_value(struct i2c_adapter *adap, int val) | |
116 | { | |
117 | gpio_set_value(adap->bus_recovery_info->scl_gpio, val); | |
118 | } | |
119 | ||
120 | static int get_sda_gpio_value(struct i2c_adapter *adap) | |
121 | { | |
122 | return gpio_get_value(adap->bus_recovery_info->sda_gpio); | |
123 | } | |
124 | ||
125 | static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap) | |
126 | { | |
127 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
128 | struct device *dev = &adap->dev; | |
129 | int ret = 0; | |
130 | ||
131 | ret = gpio_request_one(bri->scl_gpio, GPIOF_OPEN_DRAIN | | |
132 | GPIOF_OUT_INIT_HIGH, "i2c-scl"); | |
133 | if (ret) { | |
134 | dev_warn(dev, "Can't get SCL gpio: %d\n", bri->scl_gpio); | |
135 | return ret; | |
136 | } | |
137 | ||
138 | if (bri->get_sda) { | |
139 | if (gpio_request_one(bri->sda_gpio, GPIOF_IN, "i2c-sda")) { | |
140 | /* work without SDA polling */ | |
141 | dev_warn(dev, "Can't get SDA gpio: %d. Not using SDA polling\n", | |
142 | bri->sda_gpio); | |
143 | bri->get_sda = NULL; | |
144 | } | |
145 | } | |
146 | ||
147 | return ret; | |
148 | } | |
149 | ||
150 | static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap) | |
151 | { | |
152 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
153 | ||
154 | if (bri->get_sda) | |
155 | gpio_free(bri->sda_gpio); | |
156 | ||
157 | gpio_free(bri->scl_gpio); | |
158 | } | |
159 | ||
160 | /* | |
161 | * We are generating clock pulses. ndelay() determines durating of clk pulses. | |
162 | * We will generate clock with rate 100 KHz and so duration of both clock levels | |
163 | * is: delay in ns = (10^6 / 100) / 2 | |
164 | */ | |
165 | #define RECOVERY_NDELAY 5000 | |
166 | #define RECOVERY_CLK_CNT 9 | |
167 | ||
168 | static int i2c_generic_recovery(struct i2c_adapter *adap) | |
169 | { | |
170 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
171 | int i = 0, val = 1, ret = 0; | |
172 | ||
173 | if (bri->prepare_recovery) | |
174 | bri->prepare_recovery(bri); | |
175 | ||
176 | /* | |
177 | * By this time SCL is high, as we need to give 9 falling-rising edges | |
178 | */ | |
179 | while (i++ < RECOVERY_CLK_CNT * 2) { | |
180 | if (val) { | |
181 | /* Break if SDA is high */ | |
182 | if (bri->get_sda && bri->get_sda(adap)) | |
183 | break; | |
184 | /* SCL shouldn't be low here */ | |
185 | if (!bri->get_scl(adap)) { | |
186 | dev_err(&adap->dev, | |
187 | "SCL is stuck low, exit recovery\n"); | |
188 | ret = -EBUSY; | |
189 | break; | |
190 | } | |
191 | } | |
192 | ||
193 | val = !val; | |
194 | bri->set_scl(adap, val); | |
195 | ndelay(RECOVERY_NDELAY); | |
196 | } | |
197 | ||
198 | if (bri->unprepare_recovery) | |
199 | bri->unprepare_recovery(bri); | |
200 | ||
201 | return ret; | |
202 | } | |
203 | ||
204 | int i2c_generic_scl_recovery(struct i2c_adapter *adap) | |
205 | { | |
206 | adap->bus_recovery_info->set_scl(adap, 1); | |
207 | return i2c_generic_recovery(adap); | |
208 | } | |
209 | ||
210 | int i2c_generic_gpio_recovery(struct i2c_adapter *adap) | |
211 | { | |
212 | int ret; | |
213 | ||
214 | ret = i2c_get_gpios_for_recovery(adap); | |
215 | if (ret) | |
216 | return ret; | |
217 | ||
218 | ret = i2c_generic_recovery(adap); | |
219 | i2c_put_gpios_for_recovery(adap); | |
220 | ||
221 | return ret; | |
222 | } | |
223 | ||
224 | int i2c_recover_bus(struct i2c_adapter *adap) | |
225 | { | |
226 | if (!adap->bus_recovery_info) | |
227 | return -EOPNOTSUPP; | |
228 | ||
229 | dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); | |
230 | return adap->bus_recovery_info->recover_bus(adap); | |
231 | } | |
232 | ||
f37dd80a | 233 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 234 | { |
51298d12 JD |
235 | struct i2c_client *client = i2c_verify_client(dev); |
236 | struct i2c_driver *driver; | |
50c3304a | 237 | int status; |
7b4fbc50 | 238 | |
51298d12 JD |
239 | if (!client) |
240 | return 0; | |
241 | ||
242 | driver = to_i2c_driver(dev->driver); | |
e0457442 | 243 | if (!driver->probe || !driver->id_table) |
7b4fbc50 DB |
244 | return -ENODEV; |
245 | client->driver = driver; | |
ee35425c MP |
246 | if (!device_can_wakeup(&client->dev)) |
247 | device_init_wakeup(&client->dev, | |
248 | client->flags & I2C_CLIENT_WAKE); | |
7b4fbc50 | 249 | dev_dbg(dev, "probe\n"); |
d2653e92 | 250 | |
e0457442 | 251 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
e4a7b9b0 | 252 | if (status) { |
50c3304a | 253 | client->driver = NULL; |
e4a7b9b0 WS |
254 | i2c_set_clientdata(client, NULL); |
255 | } | |
50c3304a | 256 | return status; |
f37dd80a | 257 | } |
1da177e4 | 258 | |
f37dd80a DB |
259 | static int i2c_device_remove(struct device *dev) |
260 | { | |
51298d12 | 261 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 DB |
262 | struct i2c_driver *driver; |
263 | int status; | |
264 | ||
51298d12 | 265 | if (!client || !dev->driver) |
a1d9e6e4 DB |
266 | return 0; |
267 | ||
268 | driver = to_i2c_driver(dev->driver); | |
269 | if (driver->remove) { | |
270 | dev_dbg(dev, "remove\n"); | |
271 | status = driver->remove(client); | |
272 | } else { | |
273 | dev->driver = NULL; | |
274 | status = 0; | |
275 | } | |
e4a7b9b0 | 276 | if (status == 0) { |
a1d9e6e4 | 277 | client->driver = NULL; |
e4a7b9b0 WS |
278 | i2c_set_clientdata(client, NULL); |
279 | } | |
a1d9e6e4 | 280 | return status; |
1da177e4 LT |
281 | } |
282 | ||
f37dd80a | 283 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 284 | { |
51298d12 | 285 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
286 | struct i2c_driver *driver; |
287 | ||
51298d12 | 288 | if (!client || !dev->driver) |
f37dd80a DB |
289 | return; |
290 | driver = to_i2c_driver(dev->driver); | |
291 | if (driver->shutdown) | |
51298d12 | 292 | driver->shutdown(client); |
1da177e4 LT |
293 | } |
294 | ||
2f60ba70 RW |
295 | #ifdef CONFIG_PM_SLEEP |
296 | static int i2c_legacy_suspend(struct device *dev, pm_message_t mesg) | |
54067ee2 | 297 | { |
2f60ba70 RW |
298 | struct i2c_client *client = i2c_verify_client(dev); |
299 | struct i2c_driver *driver; | |
54067ee2 | 300 | |
2f60ba70 | 301 | if (!client || !dev->driver) |
54067ee2 | 302 | return 0; |
2f60ba70 RW |
303 | driver = to_i2c_driver(dev->driver); |
304 | if (!driver->suspend) | |
54067ee2 | 305 | return 0; |
2f60ba70 | 306 | return driver->suspend(client, mesg); |
54067ee2 | 307 | } |
308 | ||
2f60ba70 | 309 | static int i2c_legacy_resume(struct device *dev) |
54067ee2 | 310 | { |
2f60ba70 RW |
311 | struct i2c_client *client = i2c_verify_client(dev); |
312 | struct i2c_driver *driver; | |
54067ee2 | 313 | |
2f60ba70 | 314 | if (!client || !dev->driver) |
54067ee2 | 315 | return 0; |
2f60ba70 RW |
316 | driver = to_i2c_driver(dev->driver); |
317 | if (!driver->resume) | |
54067ee2 | 318 | return 0; |
2f60ba70 | 319 | return driver->resume(client); |
54067ee2 | 320 | } |
54067ee2 | 321 | |
2f60ba70 | 322 | static int i2c_device_pm_suspend(struct device *dev) |
6de468ae | 323 | { |
2f60ba70 | 324 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 325 | |
d529de29 MB |
326 | if (pm) |
327 | return pm_generic_suspend(dev); | |
328 | else | |
329 | return i2c_legacy_suspend(dev, PMSG_SUSPEND); | |
6de468ae MB |
330 | } |
331 | ||
2f60ba70 | 332 | static int i2c_device_pm_resume(struct device *dev) |
6de468ae | 333 | { |
2f60ba70 | 334 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 335 | |
2f60ba70 | 336 | if (pm) |
d529de29 | 337 | return pm_generic_resume(dev); |
2f60ba70 | 338 | else |
d529de29 | 339 | return i2c_legacy_resume(dev); |
6de468ae | 340 | } |
6de468ae | 341 | |
2f60ba70 | 342 | static int i2c_device_pm_freeze(struct device *dev) |
1da177e4 | 343 | { |
2f60ba70 | 344 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 345 | |
d529de29 MB |
346 | if (pm) |
347 | return pm_generic_freeze(dev); | |
348 | else | |
349 | return i2c_legacy_suspend(dev, PMSG_FREEZE); | |
1da177e4 LT |
350 | } |
351 | ||
2f60ba70 | 352 | static int i2c_device_pm_thaw(struct device *dev) |
1da177e4 | 353 | { |
2f60ba70 | 354 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 355 | |
d529de29 MB |
356 | if (pm) |
357 | return pm_generic_thaw(dev); | |
358 | else | |
359 | return i2c_legacy_resume(dev); | |
2f60ba70 RW |
360 | } |
361 | ||
362 | static int i2c_device_pm_poweroff(struct device *dev) | |
363 | { | |
364 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
365 | ||
d529de29 MB |
366 | if (pm) |
367 | return pm_generic_poweroff(dev); | |
368 | else | |
369 | return i2c_legacy_suspend(dev, PMSG_HIBERNATE); | |
2f60ba70 RW |
370 | } |
371 | ||
372 | static int i2c_device_pm_restore(struct device *dev) | |
373 | { | |
374 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
2f60ba70 RW |
375 | |
376 | if (pm) | |
d529de29 | 377 | return pm_generic_restore(dev); |
2f60ba70 | 378 | else |
d529de29 | 379 | return i2c_legacy_resume(dev); |
1da177e4 | 380 | } |
2f60ba70 RW |
381 | #else /* !CONFIG_PM_SLEEP */ |
382 | #define i2c_device_pm_suspend NULL | |
383 | #define i2c_device_pm_resume NULL | |
384 | #define i2c_device_pm_freeze NULL | |
385 | #define i2c_device_pm_thaw NULL | |
386 | #define i2c_device_pm_poweroff NULL | |
387 | #define i2c_device_pm_restore NULL | |
388 | #endif /* !CONFIG_PM_SLEEP */ | |
1da177e4 | 389 | |
9c1600ed DB |
390 | static void i2c_client_dev_release(struct device *dev) |
391 | { | |
392 | kfree(to_i2c_client(dev)); | |
393 | } | |
394 | ||
09b8ce0a | 395 | static ssize_t |
4f8cf824 | 396 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 397 | { |
4f8cf824 JD |
398 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
399 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 DB |
400 | } |
401 | ||
09b8ce0a ZX |
402 | static ssize_t |
403 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
404 | { |
405 | struct i2c_client *client = to_i2c_client(dev); | |
eb8a7908 | 406 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
407 | } |
408 | ||
4f8cf824 | 409 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
51298d12 JD |
410 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
411 | ||
412 | static struct attribute *i2c_dev_attrs[] = { | |
413 | &dev_attr_name.attr, | |
7b4fbc50 | 414 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
415 | &dev_attr_modalias.attr, |
416 | NULL | |
417 | }; | |
418 | ||
419 | static struct attribute_group i2c_dev_attr_group = { | |
420 | .attrs = i2c_dev_attrs, | |
421 | }; | |
422 | ||
423 | static const struct attribute_group *i2c_dev_attr_groups[] = { | |
424 | &i2c_dev_attr_group, | |
425 | NULL | |
7b4fbc50 DB |
426 | }; |
427 | ||
0b2c3688 | 428 | static const struct dev_pm_ops i2c_device_pm_ops = { |
54067ee2 | 429 | .suspend = i2c_device_pm_suspend, |
430 | .resume = i2c_device_pm_resume, | |
2f60ba70 RW |
431 | .freeze = i2c_device_pm_freeze, |
432 | .thaw = i2c_device_pm_thaw, | |
433 | .poweroff = i2c_device_pm_poweroff, | |
434 | .restore = i2c_device_pm_restore, | |
435 | SET_RUNTIME_PM_OPS( | |
436 | pm_generic_runtime_suspend, | |
437 | pm_generic_runtime_resume, | |
45f0a85c | 438 | NULL |
2f60ba70 | 439 | ) |
54067ee2 | 440 | }; |
441 | ||
e9ca9eb9 | 442 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
443 | .name = "i2c", |
444 | .match = i2c_device_match, | |
445 | .probe = i2c_device_probe, | |
446 | .remove = i2c_device_remove, | |
447 | .shutdown = i2c_device_shutdown, | |
54067ee2 | 448 | .pm = &i2c_device_pm_ops, |
b864c7d5 | 449 | }; |
e9ca9eb9 | 450 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 451 | |
51298d12 JD |
452 | static struct device_type i2c_client_type = { |
453 | .groups = i2c_dev_attr_groups, | |
454 | .uevent = i2c_device_uevent, | |
455 | .release = i2c_client_dev_release, | |
456 | }; | |
457 | ||
9b766b81 DB |
458 | |
459 | /** | |
460 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
461 | * @dev: device, probably from some driver model iterator | |
462 | * | |
463 | * When traversing the driver model tree, perhaps using driver model | |
464 | * iterators like @device_for_each_child(), you can't assume very much | |
465 | * about the nodes you find. Use this function to avoid oopses caused | |
466 | * by wrongly treating some non-I2C device as an i2c_client. | |
467 | */ | |
468 | struct i2c_client *i2c_verify_client(struct device *dev) | |
469 | { | |
51298d12 | 470 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
471 | ? to_i2c_client(dev) |
472 | : NULL; | |
473 | } | |
474 | EXPORT_SYMBOL(i2c_verify_client); | |
475 | ||
476 | ||
3a89db5f | 477 | /* This is a permissive address validity check, I2C address map constraints |
25985edc | 478 | * are purposely not enforced, except for the general call address. */ |
3a89db5f JD |
479 | static int i2c_check_client_addr_validity(const struct i2c_client *client) |
480 | { | |
481 | if (client->flags & I2C_CLIENT_TEN) { | |
482 | /* 10-bit address, all values are valid */ | |
483 | if (client->addr > 0x3ff) | |
484 | return -EINVAL; | |
485 | } else { | |
486 | /* 7-bit address, reject the general call address */ | |
487 | if (client->addr == 0x00 || client->addr > 0x7f) | |
488 | return -EINVAL; | |
489 | } | |
490 | return 0; | |
491 | } | |
492 | ||
656b8761 JD |
493 | /* And this is a strict address validity check, used when probing. If a |
494 | * device uses a reserved address, then it shouldn't be probed. 7-bit | |
495 | * addressing is assumed, 10-bit address devices are rare and should be | |
496 | * explicitly enumerated. */ | |
497 | static int i2c_check_addr_validity(unsigned short addr) | |
498 | { | |
499 | /* | |
500 | * Reserved addresses per I2C specification: | |
501 | * 0x00 General call address / START byte | |
502 | * 0x01 CBUS address | |
503 | * 0x02 Reserved for different bus format | |
504 | * 0x03 Reserved for future purposes | |
505 | * 0x04-0x07 Hs-mode master code | |
506 | * 0x78-0x7b 10-bit slave addressing | |
507 | * 0x7c-0x7f Reserved for future purposes | |
508 | */ | |
509 | if (addr < 0x08 || addr > 0x77) | |
510 | return -EINVAL; | |
511 | return 0; | |
512 | } | |
513 | ||
3b5f794b JD |
514 | static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
515 | { | |
516 | struct i2c_client *client = i2c_verify_client(dev); | |
517 | int addr = *(int *)addrp; | |
518 | ||
519 | if (client && client->addr == addr) | |
520 | return -EBUSY; | |
521 | return 0; | |
522 | } | |
523 | ||
0826374b ML |
524 | /* walk up mux tree */ |
525 | static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
526 | { | |
97cc4d49 | 527 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
528 | int result; |
529 | ||
530 | result = device_for_each_child(&adapter->dev, &addr, | |
531 | __i2c_check_addr_busy); | |
532 | ||
97cc4d49 JD |
533 | if (!result && parent) |
534 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
535 | |
536 | return result; | |
537 | } | |
538 | ||
539 | /* recurse down mux tree */ | |
540 | static int i2c_check_mux_children(struct device *dev, void *addrp) | |
541 | { | |
542 | int result; | |
543 | ||
544 | if (dev->type == &i2c_adapter_type) | |
545 | result = device_for_each_child(dev, addrp, | |
546 | i2c_check_mux_children); | |
547 | else | |
548 | result = __i2c_check_addr_busy(dev, addrp); | |
549 | ||
550 | return result; | |
551 | } | |
552 | ||
3b5f794b JD |
553 | static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) |
554 | { | |
97cc4d49 | 555 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
556 | int result = 0; |
557 | ||
97cc4d49 JD |
558 | if (parent) |
559 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
560 | |
561 | if (!result) | |
562 | result = device_for_each_child(&adapter->dev, &addr, | |
563 | i2c_check_mux_children); | |
564 | ||
565 | return result; | |
3b5f794b JD |
566 | } |
567 | ||
fe61e07e JD |
568 | /** |
569 | * i2c_lock_adapter - Get exclusive access to an I2C bus segment | |
570 | * @adapter: Target I2C bus segment | |
571 | */ | |
572 | void i2c_lock_adapter(struct i2c_adapter *adapter) | |
573 | { | |
97cc4d49 JD |
574 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
575 | ||
576 | if (parent) | |
577 | i2c_lock_adapter(parent); | |
0826374b ML |
578 | else |
579 | rt_mutex_lock(&adapter->bus_lock); | |
fe61e07e JD |
580 | } |
581 | EXPORT_SYMBOL_GPL(i2c_lock_adapter); | |
582 | ||
583 | /** | |
584 | * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment | |
585 | * @adapter: Target I2C bus segment | |
586 | */ | |
587 | static int i2c_trylock_adapter(struct i2c_adapter *adapter) | |
588 | { | |
97cc4d49 JD |
589 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
590 | ||
591 | if (parent) | |
592 | return i2c_trylock_adapter(parent); | |
0826374b ML |
593 | else |
594 | return rt_mutex_trylock(&adapter->bus_lock); | |
fe61e07e JD |
595 | } |
596 | ||
597 | /** | |
598 | * i2c_unlock_adapter - Release exclusive access to an I2C bus segment | |
599 | * @adapter: Target I2C bus segment | |
600 | */ | |
601 | void i2c_unlock_adapter(struct i2c_adapter *adapter) | |
602 | { | |
97cc4d49 JD |
603 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
604 | ||
605 | if (parent) | |
606 | i2c_unlock_adapter(parent); | |
0826374b ML |
607 | else |
608 | rt_mutex_unlock(&adapter->bus_lock); | |
fe61e07e JD |
609 | } |
610 | EXPORT_SYMBOL_GPL(i2c_unlock_adapter); | |
611 | ||
9c1600ed | 612 | /** |
f8a227e8 | 613 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
614 | * @adap: the adapter managing the device |
615 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 616 | * Context: can sleep |
9c1600ed | 617 | * |
f8a227e8 JD |
618 | * Create an i2c device. Binding is handled through driver model |
619 | * probe()/remove() methods. A driver may be bound to this device when we | |
620 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
621 | * load the driver module). This call is not appropriate for use by mainboard | |
622 | * initialization logic, which usually runs during an arch_initcall() long | |
623 | * before any i2c_adapter could exist. | |
9c1600ed DB |
624 | * |
625 | * This returns the new i2c client, which may be saved for later use with | |
626 | * i2c_unregister_device(); or NULL to indicate an error. | |
627 | */ | |
628 | struct i2c_client * | |
629 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
630 | { | |
631 | struct i2c_client *client; | |
632 | int status; | |
633 | ||
634 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
635 | if (!client) | |
636 | return NULL; | |
637 | ||
638 | client->adapter = adap; | |
639 | ||
640 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 641 | |
11f1f2af AV |
642 | if (info->archdata) |
643 | client->dev.archdata = *info->archdata; | |
644 | ||
ee35425c | 645 | client->flags = info->flags; |
9c1600ed DB |
646 | client->addr = info->addr; |
647 | client->irq = info->irq; | |
648 | ||
9c1600ed DB |
649 | strlcpy(client->name, info->type, sizeof(client->name)); |
650 | ||
3a89db5f JD |
651 | /* Check for address validity */ |
652 | status = i2c_check_client_addr_validity(client); | |
653 | if (status) { | |
654 | dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", | |
655 | client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); | |
656 | goto out_err_silent; | |
657 | } | |
658 | ||
f8a227e8 | 659 | /* Check for address business */ |
3b5f794b | 660 | status = i2c_check_addr_busy(adap, client->addr); |
f8a227e8 JD |
661 | if (status) |
662 | goto out_err; | |
663 | ||
664 | client->dev.parent = &client->adapter->dev; | |
665 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 666 | client->dev.type = &i2c_client_type; |
d12d42f7 | 667 | client->dev.of_node = info->of_node; |
907ddf89 | 668 | ACPI_HANDLE_SET(&client->dev, info->acpi_node.handle); |
f8a227e8 | 669 | |
cbb44514 | 670 | /* For 10-bit clients, add an arbitrary offset to avoid collisions */ |
f8a227e8 | 671 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), |
cbb44514 JD |
672 | client->addr | ((client->flags & I2C_CLIENT_TEN) |
673 | ? 0xa000 : 0)); | |
f8a227e8 JD |
674 | status = device_register(&client->dev); |
675 | if (status) | |
676 | goto out_err; | |
677 | ||
f8a227e8 JD |
678 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
679 | client->name, dev_name(&client->dev)); | |
680 | ||
9c1600ed | 681 | return client; |
f8a227e8 JD |
682 | |
683 | out_err: | |
684 | dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " | |
685 | "(%d)\n", client->name, client->addr, status); | |
3a89db5f | 686 | out_err_silent: |
f8a227e8 JD |
687 | kfree(client); |
688 | return NULL; | |
9c1600ed DB |
689 | } |
690 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
691 | ||
692 | ||
693 | /** | |
694 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
695 | * @client: value returned from i2c_new_device() | |
d64f73be | 696 | * Context: can sleep |
9c1600ed DB |
697 | */ |
698 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 699 | { |
a1d9e6e4 DB |
700 | device_unregister(&client->dev); |
701 | } | |
9c1600ed | 702 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
703 | |
704 | ||
60b129d7 JD |
705 | static const struct i2c_device_id dummy_id[] = { |
706 | { "dummy", 0 }, | |
707 | { }, | |
708 | }; | |
709 | ||
d2653e92 JD |
710 | static int dummy_probe(struct i2c_client *client, |
711 | const struct i2c_device_id *id) | |
712 | { | |
713 | return 0; | |
714 | } | |
715 | ||
716 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
717 | { |
718 | return 0; | |
719 | } | |
720 | ||
721 | static struct i2c_driver dummy_driver = { | |
722 | .driver.name = "dummy", | |
d2653e92 JD |
723 | .probe = dummy_probe, |
724 | .remove = dummy_remove, | |
60b129d7 | 725 | .id_table = dummy_id, |
e9f1373b DB |
726 | }; |
727 | ||
728 | /** | |
729 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
730 | * @adapter: the adapter managing the device | |
731 | * @address: seven bit address to be used | |
e9f1373b DB |
732 | * Context: can sleep |
733 | * | |
734 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
735 | * with devices that consume multiple addresses. Examples of such chips | |
736 | * include various EEPROMS (like 24c04 and 24c08 models). | |
737 | * | |
738 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
739 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
740 | * And second, this prevents the specified address from being bound to a | |
741 | * different driver. | |
742 | * | |
743 | * This returns the new i2c client, which should be saved for later use with | |
744 | * i2c_unregister_device(); or NULL to indicate an error. | |
745 | */ | |
09b8ce0a | 746 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
747 | { |
748 | struct i2c_board_info info = { | |
60b129d7 | 749 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
750 | }; |
751 | ||
e9f1373b DB |
752 | return i2c_new_device(adapter, &info); |
753 | } | |
754 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
755 | ||
f37dd80a DB |
756 | /* ------------------------------------------------------------------------- */ |
757 | ||
16ffadfc DB |
758 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
759 | ||
83eaaed0 | 760 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 761 | { |
ef2c8321 | 762 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
763 | complete(&adap->dev_released); |
764 | } | |
765 | ||
390946b1 JD |
766 | /* |
767 | * This function is only needed for mutex_lock_nested, so it is never | |
768 | * called unless locking correctness checking is enabled. Thus we | |
769 | * make it inline to avoid a compiler warning. That's what gcc ends up | |
770 | * doing anyway. | |
771 | */ | |
772 | static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) | |
773 | { | |
774 | unsigned int depth = 0; | |
775 | ||
776 | while ((adapter = i2c_parent_is_i2c_adapter(adapter))) | |
777 | depth++; | |
778 | ||
779 | return depth; | |
780 | } | |
781 | ||
99cd8e25 JD |
782 | /* |
783 | * Let users instantiate I2C devices through sysfs. This can be used when | |
784 | * platform initialization code doesn't contain the proper data for | |
785 | * whatever reason. Also useful for drivers that do device detection and | |
786 | * detection fails, either because the device uses an unexpected address, | |
787 | * or this is a compatible device with different ID register values. | |
788 | * | |
789 | * Parameter checking may look overzealous, but we really don't want | |
790 | * the user to provide incorrect parameters. | |
791 | */ | |
792 | static ssize_t | |
793 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
794 | const char *buf, size_t count) | |
795 | { | |
796 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
797 | struct i2c_board_info info; | |
798 | struct i2c_client *client; | |
799 | char *blank, end; | |
800 | int res; | |
801 | ||
99cd8e25 JD |
802 | memset(&info, 0, sizeof(struct i2c_board_info)); |
803 | ||
804 | blank = strchr(buf, ' '); | |
805 | if (!blank) { | |
806 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
807 | return -EINVAL; | |
808 | } | |
809 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
810 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
811 | return -EINVAL; | |
812 | } | |
813 | memcpy(info.type, buf, blank - buf); | |
814 | ||
815 | /* Parse remaining parameters, reject extra parameters */ | |
816 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
817 | if (res < 1) { | |
818 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
819 | return -EINVAL; | |
820 | } | |
821 | if (res > 1 && end != '\n') { | |
822 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
823 | return -EINVAL; | |
824 | } | |
825 | ||
99cd8e25 JD |
826 | client = i2c_new_device(adap, &info); |
827 | if (!client) | |
3a89db5f | 828 | return -EINVAL; |
99cd8e25 JD |
829 | |
830 | /* Keep track of the added device */ | |
dafc50d1 | 831 | mutex_lock(&adap->userspace_clients_lock); |
6629dcff | 832 | list_add_tail(&client->detected, &adap->userspace_clients); |
dafc50d1 | 833 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
834 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
835 | info.type, info.addr); | |
836 | ||
837 | return count; | |
838 | } | |
839 | ||
840 | /* | |
841 | * And of course let the users delete the devices they instantiated, if | |
842 | * they got it wrong. This interface can only be used to delete devices | |
843 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
844 | * don't delete devices to which some kernel code still has references. | |
845 | * | |
846 | * Parameter checking may look overzealous, but we really don't want | |
847 | * the user to delete the wrong device. | |
848 | */ | |
849 | static ssize_t | |
850 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
851 | const char *buf, size_t count) | |
852 | { | |
853 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
854 | struct i2c_client *client, *next; | |
855 | unsigned short addr; | |
856 | char end; | |
857 | int res; | |
858 | ||
859 | /* Parse parameters, reject extra parameters */ | |
860 | res = sscanf(buf, "%hi%c", &addr, &end); | |
861 | if (res < 1) { | |
862 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
863 | return -EINVAL; | |
864 | } | |
865 | if (res > 1 && end != '\n') { | |
866 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
867 | return -EINVAL; | |
868 | } | |
869 | ||
870 | /* Make sure the device was added through sysfs */ | |
871 | res = -ENOENT; | |
390946b1 JD |
872 | mutex_lock_nested(&adap->userspace_clients_lock, |
873 | i2c_adapter_depth(adap)); | |
6629dcff JD |
874 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
875 | detected) { | |
876 | if (client->addr == addr) { | |
99cd8e25 JD |
877 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
878 | "delete_device", client->name, client->addr); | |
879 | ||
880 | list_del(&client->detected); | |
881 | i2c_unregister_device(client); | |
882 | res = count; | |
883 | break; | |
884 | } | |
885 | } | |
dafc50d1 | 886 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
887 | |
888 | if (res < 0) | |
889 | dev_err(dev, "%s: Can't find device in list\n", | |
890 | "delete_device"); | |
891 | return res; | |
892 | } | |
893 | ||
4f8cf824 | 894 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
e9b526fe AS |
895 | static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, |
896 | i2c_sysfs_delete_device); | |
4f8cf824 JD |
897 | |
898 | static struct attribute *i2c_adapter_attrs[] = { | |
899 | &dev_attr_name.attr, | |
900 | &dev_attr_new_device.attr, | |
901 | &dev_attr_delete_device.attr, | |
902 | NULL | |
903 | }; | |
904 | ||
905 | static struct attribute_group i2c_adapter_attr_group = { | |
906 | .attrs = i2c_adapter_attrs, | |
907 | }; | |
908 | ||
909 | static const struct attribute_group *i2c_adapter_attr_groups[] = { | |
910 | &i2c_adapter_attr_group, | |
911 | NULL | |
16ffadfc | 912 | }; |
b119dc3f | 913 | |
0826374b | 914 | struct device_type i2c_adapter_type = { |
4f8cf824 JD |
915 | .groups = i2c_adapter_attr_groups, |
916 | .release = i2c_adapter_dev_release, | |
1da177e4 | 917 | }; |
0826374b | 918 | EXPORT_SYMBOL_GPL(i2c_adapter_type); |
1da177e4 | 919 | |
643dd09e SW |
920 | /** |
921 | * i2c_verify_adapter - return parameter as i2c_adapter or NULL | |
922 | * @dev: device, probably from some driver model iterator | |
923 | * | |
924 | * When traversing the driver model tree, perhaps using driver model | |
925 | * iterators like @device_for_each_child(), you can't assume very much | |
926 | * about the nodes you find. Use this function to avoid oopses caused | |
927 | * by wrongly treating some non-I2C device as an i2c_adapter. | |
928 | */ | |
929 | struct i2c_adapter *i2c_verify_adapter(struct device *dev) | |
930 | { | |
931 | return (dev->type == &i2c_adapter_type) | |
932 | ? to_i2c_adapter(dev) | |
933 | : NULL; | |
934 | } | |
935 | EXPORT_SYMBOL(i2c_verify_adapter); | |
936 | ||
2bb5095a JD |
937 | #ifdef CONFIG_I2C_COMPAT |
938 | static struct class_compat *i2c_adapter_compat_class; | |
939 | #endif | |
940 | ||
9c1600ed DB |
941 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
942 | { | |
943 | struct i2c_devinfo *devinfo; | |
944 | ||
f18c41da | 945 | down_read(&__i2c_board_lock); |
9c1600ed DB |
946 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
947 | if (devinfo->busnum == adapter->nr | |
948 | && !i2c_new_device(adapter, | |
949 | &devinfo->board_info)) | |
09b8ce0a ZX |
950 | dev_err(&adapter->dev, |
951 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
952 | devinfo->board_info.addr); |
953 | } | |
f18c41da | 954 | up_read(&__i2c_board_lock); |
9c1600ed DB |
955 | } |
956 | ||
69b0089a JD |
957 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
958 | struct i2c_adapter *adap) | |
026526f5 | 959 | { |
4735c98f JD |
960 | /* Detect supported devices on that bus, and instantiate them */ |
961 | i2c_detect(adap, driver); | |
962 | ||
963 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 | 964 | if (driver->attach_adapter) { |
a920ff41 JD |
965 | dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n", |
966 | driver->driver.name); | |
fe6fc258 JD |
967 | dev_warn(&adap->dev, "Please use another way to instantiate " |
968 | "your i2c_client\n"); | |
026526f5 JD |
969 | /* We ignore the return code; if it fails, too bad */ |
970 | driver->attach_adapter(adap); | |
971 | } | |
972 | return 0; | |
973 | } | |
974 | ||
69b0089a JD |
975 | static int __process_new_adapter(struct device_driver *d, void *data) |
976 | { | |
977 | return i2c_do_add_adapter(to_i2c_driver(d), data); | |
978 | } | |
979 | ||
6e13e641 | 980 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 981 | { |
d6703281 | 982 | int res = 0; |
1da177e4 | 983 | |
1d0b19c9 | 984 | /* Can't register until after driver model init */ |
35fc37f8 JD |
985 | if (unlikely(WARN_ON(!i2c_bus_type.p))) { |
986 | res = -EAGAIN; | |
987 | goto out_list; | |
988 | } | |
1d0b19c9 | 989 | |
2236baa7 JD |
990 | /* Sanity checks */ |
991 | if (unlikely(adap->name[0] == '\0')) { | |
992 | pr_err("i2c-core: Attempt to register an adapter with " | |
993 | "no name!\n"); | |
994 | return -EINVAL; | |
995 | } | |
996 | if (unlikely(!adap->algo)) { | |
997 | pr_err("i2c-core: Attempt to register adapter '%s' with " | |
998 | "no algo!\n", adap->name); | |
999 | return -EINVAL; | |
1000 | } | |
1001 | ||
194684e5 | 1002 | rt_mutex_init(&adap->bus_lock); |
dafc50d1 | 1003 | mutex_init(&adap->userspace_clients_lock); |
6629dcff | 1004 | INIT_LIST_HEAD(&adap->userspace_clients); |
1da177e4 | 1005 | |
8fcfef6e JD |
1006 | /* Set default timeout to 1 second if not already set */ |
1007 | if (adap->timeout == 0) | |
1008 | adap->timeout = HZ; | |
1009 | ||
27d9c183 | 1010 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
1011 | adap->dev.bus = &i2c_bus_type; |
1012 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 JD |
1013 | res = device_register(&adap->dev); |
1014 | if (res) | |
1015 | goto out_list; | |
1da177e4 | 1016 | |
b6d7b3d1 JD |
1017 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
1018 | ||
2bb5095a JD |
1019 | #ifdef CONFIG_I2C_COMPAT |
1020 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
1021 | adap->dev.parent); | |
1022 | if (res) | |
1023 | dev_warn(&adap->dev, | |
1024 | "Failed to create compatibility class link\n"); | |
1025 | #endif | |
1026 | ||
5f9296ba VK |
1027 | /* bus recovery specific initialization */ |
1028 | if (adap->bus_recovery_info) { | |
1029 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
1030 | ||
1031 | if (!bri->recover_bus) { | |
1032 | dev_err(&adap->dev, "No recover_bus() found, not using recovery\n"); | |
1033 | adap->bus_recovery_info = NULL; | |
1034 | goto exit_recovery; | |
1035 | } | |
1036 | ||
1037 | /* Generic GPIO recovery */ | |
1038 | if (bri->recover_bus == i2c_generic_gpio_recovery) { | |
1039 | if (!gpio_is_valid(bri->scl_gpio)) { | |
1040 | dev_err(&adap->dev, "Invalid SCL gpio, not using recovery\n"); | |
1041 | adap->bus_recovery_info = NULL; | |
1042 | goto exit_recovery; | |
1043 | } | |
1044 | ||
1045 | if (gpio_is_valid(bri->sda_gpio)) | |
1046 | bri->get_sda = get_sda_gpio_value; | |
1047 | else | |
1048 | bri->get_sda = NULL; | |
1049 | ||
1050 | bri->get_scl = get_scl_gpio_value; | |
1051 | bri->set_scl = set_scl_gpio_value; | |
1052 | } else if (!bri->set_scl || !bri->get_scl) { | |
1053 | /* Generic SCL recovery */ | |
1054 | dev_err(&adap->dev, "No {get|set}_gpio() found, not using recovery\n"); | |
1055 | adap->bus_recovery_info = NULL; | |
1056 | } | |
1057 | } | |
1058 | ||
1059 | exit_recovery: | |
729d6dd5 | 1060 | /* create pre-declared device nodes */ |
6e13e641 DB |
1061 | if (adap->nr < __i2c_first_dynamic_bus_num) |
1062 | i2c_scan_static_board_info(adap); | |
1063 | ||
4735c98f | 1064 | /* Notify drivers */ |
35fc37f8 | 1065 | mutex_lock(&core_lock); |
d6703281 | 1066 | bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); |
caada32a | 1067 | mutex_unlock(&core_lock); |
35fc37f8 JD |
1068 | |
1069 | return 0; | |
b119c6c9 | 1070 | |
b119c6c9 | 1071 | out_list: |
35fc37f8 | 1072 | mutex_lock(&core_lock); |
b119c6c9 | 1073 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
1074 | mutex_unlock(&core_lock); |
1075 | return res; | |
1da177e4 LT |
1076 | } |
1077 | ||
ee5c2744 DA |
1078 | /** |
1079 | * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 | |
1080 | * @adap: the adapter to register (with adap->nr initialized) | |
1081 | * Context: can sleep | |
1082 | * | |
1083 | * See i2c_add_numbered_adapter() for details. | |
1084 | */ | |
1085 | static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1086 | { | |
1087 | int id; | |
1088 | ||
1089 | mutex_lock(&core_lock); | |
1090 | id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, | |
1091 | GFP_KERNEL); | |
1092 | mutex_unlock(&core_lock); | |
1093 | if (id < 0) | |
1094 | return id == -ENOSPC ? -EBUSY : id; | |
1095 | ||
1096 | return i2c_register_adapter(adap); | |
1097 | } | |
1098 | ||
6e13e641 DB |
1099 | /** |
1100 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
1101 | * @adapter: the adapter to add | |
d64f73be | 1102 | * Context: can sleep |
6e13e641 DB |
1103 | * |
1104 | * This routine is used to declare an I2C adapter when its bus number | |
ee5c2744 DA |
1105 | * doesn't matter or when its bus number is specified by an dt alias. |
1106 | * Examples of bases when the bus number doesn't matter: I2C adapters | |
1107 | * dynamically added by USB links or PCI plugin cards. | |
6e13e641 DB |
1108 | * |
1109 | * When this returns zero, a new bus number was allocated and stored | |
1110 | * in adap->nr, and the specified adapter became available for clients. | |
1111 | * Otherwise, a negative errno value is returned. | |
1112 | */ | |
1113 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
1114 | { | |
ee5c2744 | 1115 | struct device *dev = &adapter->dev; |
4ae42b0f | 1116 | int id; |
6e13e641 | 1117 | |
ee5c2744 DA |
1118 | if (dev->of_node) { |
1119 | id = of_alias_get_id(dev->of_node, "i2c"); | |
1120 | if (id >= 0) { | |
1121 | adapter->nr = id; | |
1122 | return __i2c_add_numbered_adapter(adapter); | |
1123 | } | |
1124 | } | |
1125 | ||
caada32a | 1126 | mutex_lock(&core_lock); |
4ae42b0f TH |
1127 | id = idr_alloc(&i2c_adapter_idr, adapter, |
1128 | __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); | |
caada32a | 1129 | mutex_unlock(&core_lock); |
4ae42b0f TH |
1130 | if (id < 0) |
1131 | return id; | |
6e13e641 DB |
1132 | |
1133 | adapter->nr = id; | |
4ae42b0f | 1134 | |
6e13e641 DB |
1135 | return i2c_register_adapter(adapter); |
1136 | } | |
1137 | EXPORT_SYMBOL(i2c_add_adapter); | |
1138 | ||
1139 | /** | |
1140 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
1141 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 1142 | * Context: can sleep |
6e13e641 DB |
1143 | * |
1144 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
1145 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
1146 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
1147 | * is used to properly configure I2C devices. |
1148 | * | |
488bf314 GL |
1149 | * If the requested bus number is set to -1, then this function will behave |
1150 | * identically to i2c_add_adapter, and will dynamically assign a bus number. | |
1151 | * | |
6e13e641 DB |
1152 | * If no devices have pre-been declared for this bus, then be sure to |
1153 | * register the adapter before any dynamically allocated ones. Otherwise | |
1154 | * the required bus ID may not be available. | |
1155 | * | |
1156 | * When this returns zero, the specified adapter became available for | |
1157 | * clients using the bus number provided in adap->nr. Also, the table | |
1158 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
1159 | * and the appropriate driver model device nodes are created. Otherwise, a | |
1160 | * negative errno value is returned. | |
1161 | */ | |
1162 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1163 | { | |
488bf314 GL |
1164 | if (adap->nr == -1) /* -1 means dynamically assign bus id */ |
1165 | return i2c_add_adapter(adap); | |
6e13e641 | 1166 | |
ee5c2744 | 1167 | return __i2c_add_numbered_adapter(adap); |
6e13e641 DB |
1168 | } |
1169 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
1170 | ||
19baba4c | 1171 | static void i2c_do_del_adapter(struct i2c_driver *driver, |
69b0089a | 1172 | struct i2c_adapter *adapter) |
026526f5 | 1173 | { |
4735c98f | 1174 | struct i2c_client *client, *_n; |
026526f5 | 1175 | |
acec211c JD |
1176 | /* Remove the devices we created ourselves as the result of hardware |
1177 | * probing (using a driver's detect method) */ | |
4735c98f JD |
1178 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
1179 | if (client->adapter == adapter) { | |
1180 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
1181 | client->name, client->addr); | |
1182 | list_del(&client->detected); | |
1183 | i2c_unregister_device(client); | |
1184 | } | |
1185 | } | |
026526f5 JD |
1186 | } |
1187 | ||
e549c2b5 | 1188 | static int __unregister_client(struct device *dev, void *dummy) |
5219bf88 JD |
1189 | { |
1190 | struct i2c_client *client = i2c_verify_client(dev); | |
1191 | if (client && strcmp(client->name, "dummy")) | |
1192 | i2c_unregister_device(client); | |
1193 | return 0; | |
1194 | } | |
1195 | ||
1196 | static int __unregister_dummy(struct device *dev, void *dummy) | |
e549c2b5 JD |
1197 | { |
1198 | struct i2c_client *client = i2c_verify_client(dev); | |
1199 | if (client) | |
1200 | i2c_unregister_device(client); | |
1201 | return 0; | |
1202 | } | |
1203 | ||
69b0089a JD |
1204 | static int __process_removed_adapter(struct device_driver *d, void *data) |
1205 | { | |
19baba4c LPC |
1206 | i2c_do_del_adapter(to_i2c_driver(d), data); |
1207 | return 0; | |
69b0089a JD |
1208 | } |
1209 | ||
d64f73be DB |
1210 | /** |
1211 | * i2c_del_adapter - unregister I2C adapter | |
1212 | * @adap: the adapter being unregistered | |
1213 | * Context: can sleep | |
1214 | * | |
1215 | * This unregisters an I2C adapter which was previously registered | |
1216 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
1217 | */ | |
71546300 | 1218 | void i2c_del_adapter(struct i2c_adapter *adap) |
1da177e4 | 1219 | { |
35fc37f8 | 1220 | struct i2c_adapter *found; |
bbd2d9c9 | 1221 | struct i2c_client *client, *next; |
1da177e4 LT |
1222 | |
1223 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
1224 | mutex_lock(&core_lock); |
1225 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
1226 | mutex_unlock(&core_lock); | |
1227 | if (found != adap) { | |
b6d7b3d1 JD |
1228 | pr_debug("i2c-core: attempting to delete unregistered " |
1229 | "adapter [%s]\n", adap->name); | |
71546300 | 1230 | return; |
1da177e4 LT |
1231 | } |
1232 | ||
026526f5 | 1233 | /* Tell drivers about this removal */ |
35fc37f8 | 1234 | mutex_lock(&core_lock); |
19baba4c | 1235 | bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 1236 | __process_removed_adapter); |
35fc37f8 | 1237 | mutex_unlock(&core_lock); |
1da177e4 | 1238 | |
bbd2d9c9 | 1239 | /* Remove devices instantiated from sysfs */ |
390946b1 JD |
1240 | mutex_lock_nested(&adap->userspace_clients_lock, |
1241 | i2c_adapter_depth(adap)); | |
6629dcff JD |
1242 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1243 | detected) { | |
1244 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, | |
1245 | client->addr); | |
1246 | list_del(&client->detected); | |
1247 | i2c_unregister_device(client); | |
bbd2d9c9 | 1248 | } |
dafc50d1 | 1249 | mutex_unlock(&adap->userspace_clients_lock); |
bbd2d9c9 | 1250 | |
e549c2b5 | 1251 | /* Detach any active clients. This can't fail, thus we do not |
5219bf88 JD |
1252 | * check the returned value. This is a two-pass process, because |
1253 | * we can't remove the dummy devices during the first pass: they | |
1254 | * could have been instantiated by real devices wishing to clean | |
1255 | * them up properly, so we give them a chance to do that first. */ | |
19baba4c LPC |
1256 | device_for_each_child(&adap->dev, NULL, __unregister_client); |
1257 | device_for_each_child(&adap->dev, NULL, __unregister_dummy); | |
1da177e4 | 1258 | |
2bb5095a JD |
1259 | #ifdef CONFIG_I2C_COMPAT |
1260 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
1261 | adap->dev.parent); | |
1262 | #endif | |
1263 | ||
c5567521 TLSC |
1264 | /* device name is gone after device_unregister */ |
1265 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); | |
1266 | ||
1da177e4 LT |
1267 | /* clean up the sysfs representation */ |
1268 | init_completion(&adap->dev_released); | |
1da177e4 | 1269 | device_unregister(&adap->dev); |
1da177e4 LT |
1270 | |
1271 | /* wait for sysfs to drop all references */ | |
1272 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 1273 | |
6e13e641 | 1274 | /* free bus id */ |
35fc37f8 | 1275 | mutex_lock(&core_lock); |
1da177e4 | 1276 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 1277 | mutex_unlock(&core_lock); |
1da177e4 | 1278 | |
bd4bc3db JD |
1279 | /* Clear the device structure in case this adapter is ever going to be |
1280 | added again */ | |
1281 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
1da177e4 | 1282 | } |
c0564606 | 1283 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 LT |
1284 | |
1285 | ||
7b4fbc50 DB |
1286 | /* ------------------------------------------------------------------------- */ |
1287 | ||
7ae31482 JD |
1288 | int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) |
1289 | { | |
1290 | int res; | |
1291 | ||
1292 | mutex_lock(&core_lock); | |
1293 | res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); | |
1294 | mutex_unlock(&core_lock); | |
1295 | ||
1296 | return res; | |
1297 | } | |
1298 | EXPORT_SYMBOL_GPL(i2c_for_each_dev); | |
1299 | ||
69b0089a | 1300 | static int __process_new_driver(struct device *dev, void *data) |
7f101a97 | 1301 | { |
4f8cf824 JD |
1302 | if (dev->type != &i2c_adapter_type) |
1303 | return 0; | |
69b0089a | 1304 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
7f101a97 DY |
1305 | } |
1306 | ||
7b4fbc50 DB |
1307 | /* |
1308 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 1309 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
1310 | */ |
1311 | ||
de59cf9e | 1312 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 1313 | { |
7eebcb7c | 1314 | int res; |
1da177e4 | 1315 | |
1d0b19c9 DB |
1316 | /* Can't register until after driver model init */ |
1317 | if (unlikely(WARN_ON(!i2c_bus_type.p))) | |
1318 | return -EAGAIN; | |
1319 | ||
1da177e4 | 1320 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 1321 | driver->driver.owner = owner; |
1da177e4 | 1322 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 1323 | |
729d6dd5 | 1324 | /* When registration returns, the driver core |
6e13e641 DB |
1325 | * will have called probe() for all matching-but-unbound devices. |
1326 | */ | |
1da177e4 LT |
1327 | res = driver_register(&driver->driver); |
1328 | if (res) | |
7eebcb7c | 1329 | return res; |
438d6c2c | 1330 | |
f4e8db31 MB |
1331 | /* Drivers should switch to dev_pm_ops instead. */ |
1332 | if (driver->suspend) | |
1333 | pr_warn("i2c-core: driver [%s] using legacy suspend method\n", | |
1334 | driver->driver.name); | |
1335 | if (driver->resume) | |
1336 | pr_warn("i2c-core: driver [%s] using legacy resume method\n", | |
1337 | driver->driver.name); | |
1338 | ||
35d8b2e6 | 1339 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 1340 | |
4735c98f JD |
1341 | INIT_LIST_HEAD(&driver->clients); |
1342 | /* Walk the adapters that are already present */ | |
7ae31482 | 1343 | i2c_for_each_dev(driver, __process_new_driver); |
35fc37f8 | 1344 | |
7f101a97 DY |
1345 | return 0; |
1346 | } | |
1347 | EXPORT_SYMBOL(i2c_register_driver); | |
1348 | ||
69b0089a | 1349 | static int __process_removed_driver(struct device *dev, void *data) |
7f101a97 | 1350 | { |
19baba4c LPC |
1351 | if (dev->type == &i2c_adapter_type) |
1352 | i2c_do_del_adapter(data, to_i2c_adapter(dev)); | |
1353 | return 0; | |
1da177e4 LT |
1354 | } |
1355 | ||
a1d9e6e4 DB |
1356 | /** |
1357 | * i2c_del_driver - unregister I2C driver | |
1358 | * @driver: the driver being unregistered | |
d64f73be | 1359 | * Context: can sleep |
a1d9e6e4 | 1360 | */ |
b3e82096 | 1361 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 1362 | { |
7ae31482 | 1363 | i2c_for_each_dev(driver, __process_removed_driver); |
1da177e4 LT |
1364 | |
1365 | driver_unregister(&driver->driver); | |
35d8b2e6 | 1366 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 1367 | } |
c0564606 | 1368 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 1369 | |
7b4fbc50 DB |
1370 | /* ------------------------------------------------------------------------- */ |
1371 | ||
e48d3319 JD |
1372 | /** |
1373 | * i2c_use_client - increments the reference count of the i2c client structure | |
1374 | * @client: the client being referenced | |
1375 | * | |
1376 | * Each live reference to a client should be refcounted. The driver model does | |
1377 | * that automatically as part of driver binding, so that most drivers don't | |
1378 | * need to do this explicitly: they hold a reference until they're unbound | |
1379 | * from the device. | |
1380 | * | |
1381 | * A pointer to the client with the incremented reference counter is returned. | |
1382 | */ | |
1383 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 1384 | { |
6ea438ec DB |
1385 | if (client && get_device(&client->dev)) |
1386 | return client; | |
1387 | return NULL; | |
1da177e4 | 1388 | } |
c0564606 | 1389 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 1390 | |
e48d3319 JD |
1391 | /** |
1392 | * i2c_release_client - release a use of the i2c client structure | |
1393 | * @client: the client being no longer referenced | |
1394 | * | |
1395 | * Must be called when a user of a client is finished with it. | |
1396 | */ | |
1397 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 1398 | { |
6ea438ec DB |
1399 | if (client) |
1400 | put_device(&client->dev); | |
1da177e4 | 1401 | } |
c0564606 | 1402 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 1403 | |
9b766b81 DB |
1404 | struct i2c_cmd_arg { |
1405 | unsigned cmd; | |
1406 | void *arg; | |
1407 | }; | |
1408 | ||
1409 | static int i2c_cmd(struct device *dev, void *_arg) | |
1410 | { | |
1411 | struct i2c_client *client = i2c_verify_client(dev); | |
1412 | struct i2c_cmd_arg *arg = _arg; | |
1413 | ||
1414 | if (client && client->driver && client->driver->command) | |
1415 | client->driver->command(client, arg->cmd, arg->arg); | |
1416 | return 0; | |
1417 | } | |
1418 | ||
1da177e4 LT |
1419 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
1420 | { | |
9b766b81 | 1421 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 1422 | |
9b766b81 DB |
1423 | cmd_arg.cmd = cmd; |
1424 | cmd_arg.arg = arg; | |
1425 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 1426 | } |
c0564606 | 1427 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
1428 | |
1429 | static int __init i2c_init(void) | |
1430 | { | |
1431 | int retval; | |
1432 | ||
1433 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
1434 | if (retval) |
1435 | return retval; | |
2bb5095a JD |
1436 | #ifdef CONFIG_I2C_COMPAT |
1437 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
1438 | if (!i2c_adapter_compat_class) { | |
1439 | retval = -ENOMEM; | |
1440 | goto bus_err; | |
1441 | } | |
1442 | #endif | |
e9f1373b DB |
1443 | retval = i2c_add_driver(&dummy_driver); |
1444 | if (retval) | |
2bb5095a | 1445 | goto class_err; |
e9f1373b DB |
1446 | return 0; |
1447 | ||
2bb5095a JD |
1448 | class_err: |
1449 | #ifdef CONFIG_I2C_COMPAT | |
1450 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 1451 | bus_err: |
2bb5095a | 1452 | #endif |
e9f1373b DB |
1453 | bus_unregister(&i2c_bus_type); |
1454 | return retval; | |
1da177e4 LT |
1455 | } |
1456 | ||
1457 | static void __exit i2c_exit(void) | |
1458 | { | |
e9f1373b | 1459 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
1460 | #ifdef CONFIG_I2C_COMPAT |
1461 | class_compat_unregister(i2c_adapter_compat_class); | |
1462 | #endif | |
1da177e4 LT |
1463 | bus_unregister(&i2c_bus_type); |
1464 | } | |
1465 | ||
a10f9e7c DB |
1466 | /* We must initialize early, because some subsystems register i2c drivers |
1467 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1468 | */ | |
1469 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1470 | module_exit(i2c_exit); |
1471 | ||
1472 | /* ---------------------------------------------------- | |
1473 | * the functional interface to the i2c busses. | |
1474 | * ---------------------------------------------------- | |
1475 | */ | |
1476 | ||
b37d2a3a JD |
1477 | /** |
1478 | * __i2c_transfer - unlocked flavor of i2c_transfer | |
1479 | * @adap: Handle to I2C bus | |
1480 | * @msgs: One or more messages to execute before STOP is issued to | |
1481 | * terminate the operation; each message begins with a START. | |
1482 | * @num: Number of messages to be executed. | |
1483 | * | |
1484 | * Returns negative errno, else the number of messages executed. | |
1485 | * | |
1486 | * Adapter lock must be held when calling this function. No debug logging | |
1487 | * takes place. adap->algo->master_xfer existence isn't checked. | |
1488 | */ | |
1489 | int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
1490 | { | |
1491 | unsigned long orig_jiffies; | |
1492 | int ret, try; | |
1493 | ||
1494 | /* Retry automatically on arbitration loss */ | |
1495 | orig_jiffies = jiffies; | |
1496 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
1497 | ret = adap->algo->master_xfer(adap, msgs, num); | |
1498 | if (ret != -EAGAIN) | |
1499 | break; | |
1500 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
1501 | break; | |
1502 | } | |
1503 | ||
1504 | return ret; | |
1505 | } | |
1506 | EXPORT_SYMBOL(__i2c_transfer); | |
1507 | ||
a1cdedac DB |
1508 | /** |
1509 | * i2c_transfer - execute a single or combined I2C message | |
1510 | * @adap: Handle to I2C bus | |
1511 | * @msgs: One or more messages to execute before STOP is issued to | |
1512 | * terminate the operation; each message begins with a START. | |
1513 | * @num: Number of messages to be executed. | |
1514 | * | |
1515 | * Returns negative errno, else the number of messages executed. | |
1516 | * | |
1517 | * Note that there is no requirement that each message be sent to | |
1518 | * the same slave address, although that is the most common model. | |
1519 | */ | |
09b8ce0a | 1520 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 1521 | { |
b37d2a3a | 1522 | int ret; |
1da177e4 | 1523 | |
a1cdedac DB |
1524 | /* REVISIT the fault reporting model here is weak: |
1525 | * | |
1526 | * - When we get an error after receiving N bytes from a slave, | |
1527 | * there is no way to report "N". | |
1528 | * | |
1529 | * - When we get a NAK after transmitting N bytes to a slave, | |
1530 | * there is no way to report "N" ... or to let the master | |
1531 | * continue executing the rest of this combined message, if | |
1532 | * that's the appropriate response. | |
1533 | * | |
1534 | * - When for example "num" is two and we successfully complete | |
1535 | * the first message but get an error part way through the | |
1536 | * second, it's unclear whether that should be reported as | |
1537 | * one (discarding status on the second message) or errno | |
1538 | * (discarding status on the first one). | |
1539 | */ | |
1540 | ||
1da177e4 LT |
1541 | if (adap->algo->master_xfer) { |
1542 | #ifdef DEBUG | |
1543 | for (ret = 0; ret < num; ret++) { | |
1544 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
1545 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
1546 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
1547 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
1548 | } |
1549 | #endif | |
1550 | ||
cea443a8 | 1551 | if (in_atomic() || irqs_disabled()) { |
fe61e07e | 1552 | ret = i2c_trylock_adapter(adap); |
cea443a8 MR |
1553 | if (!ret) |
1554 | /* I2C activity is ongoing. */ | |
1555 | return -EAGAIN; | |
1556 | } else { | |
fe61e07e | 1557 | i2c_lock_adapter(adap); |
cea443a8 MR |
1558 | } |
1559 | ||
b37d2a3a | 1560 | ret = __i2c_transfer(adap, msgs, num); |
fe61e07e | 1561 | i2c_unlock_adapter(adap); |
1da177e4 LT |
1562 | |
1563 | return ret; | |
1564 | } else { | |
1565 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1566 | return -EOPNOTSUPP; |
1da177e4 LT |
1567 | } |
1568 | } | |
c0564606 | 1569 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1570 | |
a1cdedac DB |
1571 | /** |
1572 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1573 | * @client: Handle to slave device | |
1574 | * @buf: Data that will be written to the slave | |
0c43ea54 | 1575 | * @count: How many bytes to write, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1576 | * |
1577 | * Returns negative errno, or else the number of bytes written. | |
1578 | */ | |
0cc43a18 | 1579 | int i2c_master_send(const struct i2c_client *client, const char *buf, int count) |
1da177e4 LT |
1580 | { |
1581 | int ret; | |
7225acf4 | 1582 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1583 | struct i2c_msg msg; |
1584 | ||
815f55f2 JD |
1585 | msg.addr = client->addr; |
1586 | msg.flags = client->flags & I2C_M_TEN; | |
1587 | msg.len = count; | |
1588 | msg.buf = (char *)buf; | |
438d6c2c | 1589 | |
815f55f2 | 1590 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1591 | |
834aa6f3 WS |
1592 | /* |
1593 | * If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1594 | * transmitted, else error code. | |
1595 | */ | |
815f55f2 | 1596 | return (ret == 1) ? count : ret; |
1da177e4 | 1597 | } |
c0564606 | 1598 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1599 | |
a1cdedac DB |
1600 | /** |
1601 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1602 | * @client: Handle to slave device | |
1603 | * @buf: Where to store data read from slave | |
0c43ea54 | 1604 | * @count: How many bytes to read, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1605 | * |
1606 | * Returns negative errno, or else the number of bytes read. | |
1607 | */ | |
0cc43a18 | 1608 | int i2c_master_recv(const struct i2c_client *client, char *buf, int count) |
1da177e4 | 1609 | { |
7225acf4 | 1610 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1611 | struct i2c_msg msg; |
1612 | int ret; | |
815f55f2 JD |
1613 | |
1614 | msg.addr = client->addr; | |
1615 | msg.flags = client->flags & I2C_M_TEN; | |
1616 | msg.flags |= I2C_M_RD; | |
1617 | msg.len = count; | |
1618 | msg.buf = buf; | |
1619 | ||
1620 | ret = i2c_transfer(adap, &msg, 1); | |
1621 | ||
834aa6f3 WS |
1622 | /* |
1623 | * If everything went ok (i.e. 1 msg received), return #bytes received, | |
1624 | * else error code. | |
1625 | */ | |
815f55f2 | 1626 | return (ret == 1) ? count : ret; |
1da177e4 | 1627 | } |
c0564606 | 1628 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1629 | |
1da177e4 LT |
1630 | /* ---------------------------------------------------- |
1631 | * the i2c address scanning function | |
1632 | * Will not work for 10-bit addresses! | |
1633 | * ---------------------------------------------------- | |
1634 | */ | |
1da177e4 | 1635 | |
63e4e802 JD |
1636 | /* |
1637 | * Legacy default probe function, mostly relevant for SMBus. The default | |
1638 | * probe method is a quick write, but it is known to corrupt the 24RF08 | |
1639 | * EEPROMs due to a state machine bug, and could also irreversibly | |
1640 | * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, | |
1641 | * we use a short byte read instead. Also, some bus drivers don't implement | |
1642 | * quick write, so we fallback to a byte read in that case too. | |
1643 | * On x86, there is another special case for FSC hardware monitoring chips, | |
1644 | * which want regular byte reads (address 0x73.) Fortunately, these are the | |
1645 | * only known chips using this I2C address on PC hardware. | |
1646 | * Returns 1 if probe succeeded, 0 if not. | |
1647 | */ | |
1648 | static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) | |
1649 | { | |
1650 | int err; | |
1651 | union i2c_smbus_data dummy; | |
1652 | ||
1653 | #ifdef CONFIG_X86 | |
1654 | if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) | |
1655 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) | |
1656 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1657 | I2C_SMBUS_BYTE_DATA, &dummy); | |
1658 | else | |
1659 | #endif | |
8031d79b JD |
1660 | if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) |
1661 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) | |
63e4e802 JD |
1662 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, |
1663 | I2C_SMBUS_QUICK, NULL); | |
8031d79b JD |
1664 | else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) |
1665 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1666 | I2C_SMBUS_BYTE, &dummy); | |
1667 | else { | |
d63a9e85 AL |
1668 | dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", |
1669 | addr); | |
8031d79b JD |
1670 | err = -EOPNOTSUPP; |
1671 | } | |
63e4e802 JD |
1672 | |
1673 | return err >= 0; | |
1674 | } | |
1675 | ||
ccfbbd08 | 1676 | static int i2c_detect_address(struct i2c_client *temp_client, |
4735c98f JD |
1677 | struct i2c_driver *driver) |
1678 | { | |
1679 | struct i2c_board_info info; | |
1680 | struct i2c_adapter *adapter = temp_client->adapter; | |
1681 | int addr = temp_client->addr; | |
1682 | int err; | |
1683 | ||
1684 | /* Make sure the address is valid */ | |
656b8761 JD |
1685 | err = i2c_check_addr_validity(addr); |
1686 | if (err) { | |
4735c98f JD |
1687 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
1688 | addr); | |
656b8761 | 1689 | return err; |
4735c98f JD |
1690 | } |
1691 | ||
1692 | /* Skip if already in use */ | |
3b5f794b | 1693 | if (i2c_check_addr_busy(adapter, addr)) |
4735c98f JD |
1694 | return 0; |
1695 | ||
ccfbbd08 | 1696 | /* Make sure there is something at this address */ |
63e4e802 JD |
1697 | if (!i2c_default_probe(adapter, addr)) |
1698 | return 0; | |
4735c98f JD |
1699 | |
1700 | /* Finally call the custom detection function */ | |
1701 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
1702 | info.addr = addr; | |
310ec792 | 1703 | err = driver->detect(temp_client, &info); |
4735c98f JD |
1704 | if (err) { |
1705 | /* -ENODEV is returned if the detection fails. We catch it | |
1706 | here as this isn't an error. */ | |
1707 | return err == -ENODEV ? 0 : err; | |
1708 | } | |
1709 | ||
1710 | /* Consistency check */ | |
1711 | if (info.type[0] == '\0') { | |
1712 | dev_err(&adapter->dev, "%s detection function provided " | |
1713 | "no name for 0x%x\n", driver->driver.name, | |
1714 | addr); | |
1715 | } else { | |
1716 | struct i2c_client *client; | |
1717 | ||
1718 | /* Detection succeeded, instantiate the device */ | |
1719 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", | |
1720 | info.type, info.addr); | |
1721 | client = i2c_new_device(adapter, &info); | |
1722 | if (client) | |
1723 | list_add_tail(&client->detected, &driver->clients); | |
1724 | else | |
1725 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
1726 | info.type, info.addr); | |
1727 | } | |
1728 | return 0; | |
1729 | } | |
1730 | ||
1731 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
1732 | { | |
c3813d6a | 1733 | const unsigned short *address_list; |
4735c98f JD |
1734 | struct i2c_client *temp_client; |
1735 | int i, err = 0; | |
1736 | int adap_id = i2c_adapter_id(adapter); | |
1737 | ||
c3813d6a JD |
1738 | address_list = driver->address_list; |
1739 | if (!driver->detect || !address_list) | |
4735c98f JD |
1740 | return 0; |
1741 | ||
51b54ba9 JD |
1742 | /* Stop here if the classes do not match */ |
1743 | if (!(adapter->class & driver->class)) | |
1744 | return 0; | |
1745 | ||
4735c98f JD |
1746 | /* Set up a temporary client to help detect callback */ |
1747 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
1748 | if (!temp_client) | |
1749 | return -ENOMEM; | |
1750 | temp_client->adapter = adapter; | |
1751 | ||
c3813d6a | 1752 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
4735c98f | 1753 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
c3813d6a JD |
1754 | "addr 0x%02x\n", adap_id, address_list[i]); |
1755 | temp_client->addr = address_list[i]; | |
ccfbbd08 | 1756 | err = i2c_detect_address(temp_client, driver); |
51b54ba9 JD |
1757 | if (unlikely(err)) |
1758 | break; | |
4735c98f JD |
1759 | } |
1760 | ||
4735c98f JD |
1761 | kfree(temp_client); |
1762 | return err; | |
1763 | } | |
1764 | ||
d44f19d5 JD |
1765 | int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) |
1766 | { | |
1767 | return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1768 | I2C_SMBUS_QUICK, NULL) >= 0; | |
1769 | } | |
1770 | EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); | |
1771 | ||
12b5053a JD |
1772 | struct i2c_client * |
1773 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1774 | struct i2c_board_info *info, | |
9a94241a JD |
1775 | unsigned short const *addr_list, |
1776 | int (*probe)(struct i2c_adapter *, unsigned short addr)) | |
12b5053a JD |
1777 | { |
1778 | int i; | |
1779 | ||
8031d79b | 1780 | if (!probe) |
9a94241a | 1781 | probe = i2c_default_probe; |
12b5053a | 1782 | |
12b5053a JD |
1783 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1784 | /* Check address validity */ | |
656b8761 | 1785 | if (i2c_check_addr_validity(addr_list[i]) < 0) { |
12b5053a JD |
1786 | dev_warn(&adap->dev, "Invalid 7-bit address " |
1787 | "0x%02x\n", addr_list[i]); | |
1788 | continue; | |
1789 | } | |
1790 | ||
1791 | /* Check address availability */ | |
3b5f794b | 1792 | if (i2c_check_addr_busy(adap, addr_list[i])) { |
12b5053a JD |
1793 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1794 | "use, not probing\n", addr_list[i]); | |
1795 | continue; | |
1796 | } | |
1797 | ||
63e4e802 | 1798 | /* Test address responsiveness */ |
9a94241a | 1799 | if (probe(adap, addr_list[i])) |
63e4e802 | 1800 | break; |
12b5053a | 1801 | } |
12b5053a JD |
1802 | |
1803 | if (addr_list[i] == I2C_CLIENT_END) { | |
1804 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1805 | return NULL; | |
1806 | } | |
1807 | ||
1808 | info->addr = addr_list[i]; | |
1809 | return i2c_new_device(adap, info); | |
1810 | } | |
1811 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
1812 | ||
d735b34d | 1813 | struct i2c_adapter *i2c_get_adapter(int nr) |
1da177e4 | 1814 | { |
1da177e4 | 1815 | struct i2c_adapter *adapter; |
438d6c2c | 1816 | |
caada32a | 1817 | mutex_lock(&core_lock); |
d735b34d | 1818 | adapter = idr_find(&i2c_adapter_idr, nr); |
a0920e10 MH |
1819 | if (adapter && !try_module_get(adapter->owner)) |
1820 | adapter = NULL; | |
1821 | ||
caada32a | 1822 | mutex_unlock(&core_lock); |
a0920e10 | 1823 | return adapter; |
1da177e4 | 1824 | } |
c0564606 | 1825 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
1826 | |
1827 | void i2c_put_adapter(struct i2c_adapter *adap) | |
1828 | { | |
c66c4cc0 SH |
1829 | if (adap) |
1830 | module_put(adap->owner); | |
1da177e4 | 1831 | } |
c0564606 | 1832 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
1833 | |
1834 | /* The SMBus parts */ | |
1835 | ||
438d6c2c | 1836 | #define POLY (0x1070U << 3) |
09b8ce0a | 1837 | static u8 crc8(u16 data) |
1da177e4 LT |
1838 | { |
1839 | int i; | |
438d6c2c | 1840 | |
7225acf4 | 1841 | for (i = 0; i < 8; i++) { |
438d6c2c | 1842 | if (data & 0x8000) |
1da177e4 LT |
1843 | data = data ^ POLY; |
1844 | data = data << 1; | |
1845 | } | |
1846 | return (u8)(data >> 8); | |
1847 | } | |
1848 | ||
421ef47b JD |
1849 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
1850 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
1851 | { |
1852 | int i; | |
1853 | ||
7225acf4 | 1854 | for (i = 0; i < count; i++) |
421ef47b | 1855 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
1856 | return crc; |
1857 | } | |
1858 | ||
421ef47b JD |
1859 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
1860 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 1861 | { |
421ef47b JD |
1862 | /* The address will be sent first */ |
1863 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
1864 | pec = i2c_smbus_pec(pec, &addr, 1); | |
1865 | ||
1866 | /* The data buffer follows */ | |
1867 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
1868 | } |
1869 | ||
421ef47b JD |
1870 | /* Used for write only transactions */ |
1871 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 1872 | { |
421ef47b JD |
1873 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
1874 | msg->len++; | |
1da177e4 LT |
1875 | } |
1876 | ||
421ef47b JD |
1877 | /* Return <0 on CRC error |
1878 | If there was a write before this read (most cases) we need to take the | |
1879 | partial CRC from the write part into account. | |
1880 | Note that this function does modify the message (we need to decrease the | |
1881 | message length to hide the CRC byte from the caller). */ | |
1882 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 1883 | { |
421ef47b JD |
1884 | u8 rpec = msg->buf[--msg->len]; |
1885 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 1886 | |
1da177e4 LT |
1887 | if (rpec != cpec) { |
1888 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
1889 | rpec, cpec); | |
24a5bb7b | 1890 | return -EBADMSG; |
1da177e4 | 1891 | } |
438d6c2c | 1892 | return 0; |
1da177e4 LT |
1893 | } |
1894 | ||
a1cdedac DB |
1895 | /** |
1896 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
1897 | * @client: Handle to slave device | |
1898 | * | |
1899 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
1900 | * else the byte received from the device. | |
1901 | */ | |
0cc43a18 | 1902 | s32 i2c_smbus_read_byte(const struct i2c_client *client) |
1da177e4 LT |
1903 | { |
1904 | union i2c_smbus_data data; | |
24a5bb7b DB |
1905 | int status; |
1906 | ||
1907 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1908 | I2C_SMBUS_READ, 0, | |
1909 | I2C_SMBUS_BYTE, &data); | |
1910 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1911 | } |
c0564606 | 1912 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 1913 | |
a1cdedac DB |
1914 | /** |
1915 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
1916 | * @client: Handle to slave device | |
1917 | * @value: Byte to be sent | |
1918 | * | |
1919 | * This executes the SMBus "send byte" protocol, returning negative errno | |
1920 | * else zero on success. | |
1921 | */ | |
0cc43a18 | 1922 | s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value) |
1da177e4 | 1923 | { |
7225acf4 | 1924 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
421ef47b | 1925 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 1926 | } |
c0564606 | 1927 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 1928 | |
a1cdedac DB |
1929 | /** |
1930 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
1931 | * @client: Handle to slave device | |
1932 | * @command: Byte interpreted by slave | |
1933 | * | |
1934 | * This executes the SMBus "read byte" protocol, returning negative errno | |
1935 | * else a data byte received from the device. | |
1936 | */ | |
0cc43a18 | 1937 | s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command) |
1da177e4 LT |
1938 | { |
1939 | union i2c_smbus_data data; | |
24a5bb7b DB |
1940 | int status; |
1941 | ||
1942 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1943 | I2C_SMBUS_READ, command, | |
1944 | I2C_SMBUS_BYTE_DATA, &data); | |
1945 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1946 | } |
c0564606 | 1947 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 1948 | |
a1cdedac DB |
1949 | /** |
1950 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
1951 | * @client: Handle to slave device | |
1952 | * @command: Byte interpreted by slave | |
1953 | * @value: Byte being written | |
1954 | * | |
1955 | * This executes the SMBus "write byte" protocol, returning negative errno | |
1956 | * else zero on success. | |
1957 | */ | |
0cc43a18 JD |
1958 | s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command, |
1959 | u8 value) | |
1da177e4 LT |
1960 | { |
1961 | union i2c_smbus_data data; | |
1962 | data.byte = value; | |
7225acf4 FH |
1963 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1964 | I2C_SMBUS_WRITE, command, | |
1965 | I2C_SMBUS_BYTE_DATA, &data); | |
1da177e4 | 1966 | } |
c0564606 | 1967 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 1968 | |
a1cdedac DB |
1969 | /** |
1970 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
1971 | * @client: Handle to slave device | |
1972 | * @command: Byte interpreted by slave | |
1973 | * | |
1974 | * This executes the SMBus "read word" protocol, returning negative errno | |
1975 | * else a 16-bit unsigned "word" received from the device. | |
1976 | */ | |
0cc43a18 | 1977 | s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command) |
1da177e4 LT |
1978 | { |
1979 | union i2c_smbus_data data; | |
24a5bb7b DB |
1980 | int status; |
1981 | ||
1982 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1983 | I2C_SMBUS_READ, command, | |
1984 | I2C_SMBUS_WORD_DATA, &data); | |
1985 | return (status < 0) ? status : data.word; | |
1da177e4 | 1986 | } |
c0564606 | 1987 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 1988 | |
a1cdedac DB |
1989 | /** |
1990 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
1991 | * @client: Handle to slave device | |
1992 | * @command: Byte interpreted by slave | |
1993 | * @value: 16-bit "word" being written | |
1994 | * | |
1995 | * This executes the SMBus "write word" protocol, returning negative errno | |
1996 | * else zero on success. | |
1997 | */ | |
0cc43a18 JD |
1998 | s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command, |
1999 | u16 value) | |
1da177e4 LT |
2000 | { |
2001 | union i2c_smbus_data data; | |
2002 | data.word = value; | |
7225acf4 FH |
2003 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2004 | I2C_SMBUS_WRITE, command, | |
2005 | I2C_SMBUS_WORD_DATA, &data); | |
1da177e4 | 2006 | } |
c0564606 | 2007 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 2008 | |
a64ec07d | 2009 | /** |
a1cdedac | 2010 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 2011 | * @client: Handle to slave device |
a1cdedac | 2012 | * @command: Byte interpreted by slave |
a64ec07d DB |
2013 | * @values: Byte array into which data will be read; big enough to hold |
2014 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
2015 | * | |
a1cdedac DB |
2016 | * This executes the SMBus "block read" protocol, returning negative errno |
2017 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
2018 | * |
2019 | * Note that using this function requires that the client's adapter support | |
2020 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
2021 | * support this; its emulation through I2C messaging relies on a specific | |
2022 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
2023 | */ | |
0cc43a18 | 2024 | s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command, |
b86a1bc8 JD |
2025 | u8 *values) |
2026 | { | |
2027 | union i2c_smbus_data data; | |
24a5bb7b | 2028 | int status; |
b86a1bc8 | 2029 | |
24a5bb7b DB |
2030 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2031 | I2C_SMBUS_READ, command, | |
2032 | I2C_SMBUS_BLOCK_DATA, &data); | |
2033 | if (status) | |
2034 | return status; | |
b86a1bc8 JD |
2035 | |
2036 | memcpy(values, &data.block[1], data.block[0]); | |
2037 | return data.block[0]; | |
2038 | } | |
2039 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
2040 | ||
a1cdedac DB |
2041 | /** |
2042 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
2043 | * @client: Handle to slave device | |
2044 | * @command: Byte interpreted by slave | |
2045 | * @length: Size of data block; SMBus allows at most 32 bytes | |
2046 | * @values: Byte array which will be written. | |
2047 | * | |
2048 | * This executes the SMBus "block write" protocol, returning negative errno | |
2049 | * else zero on success. | |
2050 | */ | |
0cc43a18 | 2051 | s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command, |
46f5ed75 | 2052 | u8 length, const u8 *values) |
1da177e4 LT |
2053 | { |
2054 | union i2c_smbus_data data; | |
7656032b | 2055 | |
1da177e4 LT |
2056 | if (length > I2C_SMBUS_BLOCK_MAX) |
2057 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 2058 | data.block[0] = length; |
7656032b | 2059 | memcpy(&data.block[1], values, length); |
7225acf4 FH |
2060 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2061 | I2C_SMBUS_WRITE, command, | |
2062 | I2C_SMBUS_BLOCK_DATA, &data); | |
1da177e4 | 2063 | } |
c0564606 | 2064 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
2065 | |
2066 | /* Returns the number of read bytes */ | |
0cc43a18 | 2067 | s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command, |
4b2643d7 | 2068 | u8 length, u8 *values) |
1da177e4 LT |
2069 | { |
2070 | union i2c_smbus_data data; | |
24a5bb7b | 2071 | int status; |
7656032b | 2072 | |
4b2643d7 JD |
2073 | if (length > I2C_SMBUS_BLOCK_MAX) |
2074 | length = I2C_SMBUS_BLOCK_MAX; | |
2075 | data.block[0] = length; | |
24a5bb7b DB |
2076 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2077 | I2C_SMBUS_READ, command, | |
2078 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
2079 | if (status < 0) | |
2080 | return status; | |
7656032b JD |
2081 | |
2082 | memcpy(values, &data.block[1], data.block[0]); | |
2083 | return data.block[0]; | |
1da177e4 | 2084 | } |
c0564606 | 2085 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 2086 | |
0cc43a18 | 2087 | s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command, |
46f5ed75 | 2088 | u8 length, const u8 *values) |
21bbd691 JD |
2089 | { |
2090 | union i2c_smbus_data data; | |
2091 | ||
2092 | if (length > I2C_SMBUS_BLOCK_MAX) | |
2093 | length = I2C_SMBUS_BLOCK_MAX; | |
2094 | data.block[0] = length; | |
2095 | memcpy(data.block + 1, values, length); | |
2096 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2097 | I2C_SMBUS_WRITE, command, | |
2098 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
2099 | } | |
c0564606 | 2100 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 2101 | |
438d6c2c | 2102 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 2103 | No checking of parameters is done! */ |
7225acf4 FH |
2104 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, |
2105 | unsigned short flags, | |
2106 | char read_write, u8 command, int size, | |
2107 | union i2c_smbus_data *data) | |
1da177e4 LT |
2108 | { |
2109 | /* So we need to generate a series of msgs. In the case of writing, we | |
2110 | need to use only one message; when reading, we need two. We initialize | |
2111 | most things with sane defaults, to keep the code below somewhat | |
2112 | simpler. */ | |
5c50d188 HI |
2113 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
2114 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
7225acf4 | 2115 | int num = read_write == I2C_SMBUS_READ ? 2 : 1; |
1da177e4 | 2116 | int i; |
421ef47b | 2117 | u8 partial_pec = 0; |
24a5bb7b | 2118 | int status; |
230da094 S |
2119 | struct i2c_msg msg[2] = { |
2120 | { | |
2121 | .addr = addr, | |
2122 | .flags = flags, | |
2123 | .len = 1, | |
2124 | .buf = msgbuf0, | |
2125 | }, { | |
2126 | .addr = addr, | |
2127 | .flags = flags | I2C_M_RD, | |
2128 | .len = 0, | |
2129 | .buf = msgbuf1, | |
2130 | }, | |
2131 | }; | |
1da177e4 LT |
2132 | |
2133 | msgbuf0[0] = command; | |
7225acf4 | 2134 | switch (size) { |
1da177e4 LT |
2135 | case I2C_SMBUS_QUICK: |
2136 | msg[0].len = 0; | |
2137 | /* Special case: The read/write field is used as data */ | |
f29d2e02 RK |
2138 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
2139 | I2C_M_RD : 0); | |
1da177e4 LT |
2140 | num = 1; |
2141 | break; | |
2142 | case I2C_SMBUS_BYTE: | |
2143 | if (read_write == I2C_SMBUS_READ) { | |
2144 | /* Special case: only a read! */ | |
2145 | msg[0].flags = I2C_M_RD | flags; | |
2146 | num = 1; | |
2147 | } | |
2148 | break; | |
2149 | case I2C_SMBUS_BYTE_DATA: | |
2150 | if (read_write == I2C_SMBUS_READ) | |
2151 | msg[1].len = 1; | |
2152 | else { | |
2153 | msg[0].len = 2; | |
2154 | msgbuf0[1] = data->byte; | |
2155 | } | |
2156 | break; | |
2157 | case I2C_SMBUS_WORD_DATA: | |
2158 | if (read_write == I2C_SMBUS_READ) | |
2159 | msg[1].len = 2; | |
2160 | else { | |
7225acf4 | 2161 | msg[0].len = 3; |
1da177e4 | 2162 | msgbuf0[1] = data->word & 0xff; |
7eff82c8 | 2163 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
2164 | } |
2165 | break; | |
2166 | case I2C_SMBUS_PROC_CALL: | |
2167 | num = 2; /* Special case */ | |
2168 | read_write = I2C_SMBUS_READ; | |
2169 | msg[0].len = 3; | |
2170 | msg[1].len = 2; | |
2171 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 2172 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
2173 | break; |
2174 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 2175 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
2176 | msg[1].flags |= I2C_M_RECV_LEN; |
2177 | msg[1].len = 1; /* block length will be added by | |
2178 | the underlying bus driver */ | |
1da177e4 LT |
2179 | } else { |
2180 | msg[0].len = data->block[0] + 2; | |
2181 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
2182 | dev_err(&adapter->dev, |
2183 | "Invalid block write size %d\n", | |
2184 | data->block[0]); | |
2185 | return -EINVAL; | |
1da177e4 | 2186 | } |
5c50d188 | 2187 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
2188 | msgbuf0[i] = data->block[i-1]; |
2189 | } | |
2190 | break; | |
2191 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
2192 | num = 2; /* Another special case */ |
2193 | read_write = I2C_SMBUS_READ; | |
2194 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
2195 | dev_err(&adapter->dev, |
2196 | "Invalid block write size %d\n", | |
209d27c3 | 2197 | data->block[0]); |
24a5bb7b | 2198 | return -EINVAL; |
209d27c3 JD |
2199 | } |
2200 | msg[0].len = data->block[0] + 2; | |
2201 | for (i = 1; i < msg[0].len; i++) | |
2202 | msgbuf0[i] = data->block[i-1]; | |
2203 | msg[1].flags |= I2C_M_RECV_LEN; | |
2204 | msg[1].len = 1; /* block length will be added by | |
2205 | the underlying bus driver */ | |
2206 | break; | |
1da177e4 LT |
2207 | case I2C_SMBUS_I2C_BLOCK_DATA: |
2208 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 2209 | msg[1].len = data->block[0]; |
1da177e4 LT |
2210 | } else { |
2211 | msg[0].len = data->block[0] + 1; | |
30dac746 | 2212 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
2213 | dev_err(&adapter->dev, |
2214 | "Invalid block write size %d\n", | |
2215 | data->block[0]); | |
2216 | return -EINVAL; | |
1da177e4 LT |
2217 | } |
2218 | for (i = 1; i <= data->block[0]; i++) | |
2219 | msgbuf0[i] = data->block[i]; | |
2220 | } | |
2221 | break; | |
2222 | default: | |
24a5bb7b DB |
2223 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
2224 | return -EOPNOTSUPP; | |
1da177e4 LT |
2225 | } |
2226 | ||
421ef47b JD |
2227 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
2228 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
2229 | if (i) { | |
2230 | /* Compute PEC if first message is a write */ | |
2231 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 2232 | if (num == 1) /* Write only */ |
421ef47b JD |
2233 | i2c_smbus_add_pec(&msg[0]); |
2234 | else /* Write followed by read */ | |
2235 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
2236 | } | |
2237 | /* Ask for PEC if last message is a read */ | |
2238 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 2239 | msg[num-1].len++; |
421ef47b JD |
2240 | } |
2241 | ||
24a5bb7b DB |
2242 | status = i2c_transfer(adapter, msg, num); |
2243 | if (status < 0) | |
2244 | return status; | |
1da177e4 | 2245 | |
421ef47b JD |
2246 | /* Check PEC if last message is a read */ |
2247 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
2248 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
2249 | if (status < 0) | |
2250 | return status; | |
421ef47b JD |
2251 | } |
2252 | ||
1da177e4 | 2253 | if (read_write == I2C_SMBUS_READ) |
7225acf4 FH |
2254 | switch (size) { |
2255 | case I2C_SMBUS_BYTE: | |
2256 | data->byte = msgbuf0[0]; | |
2257 | break; | |
2258 | case I2C_SMBUS_BYTE_DATA: | |
2259 | data->byte = msgbuf1[0]; | |
2260 | break; | |
2261 | case I2C_SMBUS_WORD_DATA: | |
2262 | case I2C_SMBUS_PROC_CALL: | |
2263 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
2264 | break; | |
2265 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
2266 | for (i = 0; i < data->block[0]; i++) | |
2267 | data->block[i+1] = msgbuf1[i]; | |
2268 | break; | |
2269 | case I2C_SMBUS_BLOCK_DATA: | |
2270 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
2271 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
2272 | data->block[i] = msgbuf1[i]; | |
2273 | break; | |
1da177e4 LT |
2274 | } |
2275 | return 0; | |
2276 | } | |
2277 | ||
a1cdedac DB |
2278 | /** |
2279 | * i2c_smbus_xfer - execute SMBus protocol operations | |
2280 | * @adapter: Handle to I2C bus | |
2281 | * @addr: Address of SMBus slave on that bus | |
2282 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
2283 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
2284 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
2285 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
2286 | * @data: Data to be read or written | |
2287 | * | |
2288 | * This executes an SMBus protocol operation, and returns a negative | |
2289 | * errno code else zero on success. | |
2290 | */ | |
09b8ce0a | 2291 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
a1cdedac | 2292 | char read_write, u8 command, int protocol, |
09b8ce0a | 2293 | union i2c_smbus_data *data) |
1da177e4 | 2294 | { |
66b650f0 CW |
2295 | unsigned long orig_jiffies; |
2296 | int try; | |
1da177e4 | 2297 | s32 res; |
1da177e4 | 2298 | |
d47726c5 | 2299 | flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB; |
1da177e4 LT |
2300 | |
2301 | if (adapter->algo->smbus_xfer) { | |
fe61e07e | 2302 | i2c_lock_adapter(adapter); |
66b650f0 CW |
2303 | |
2304 | /* Retry automatically on arbitration loss */ | |
2305 | orig_jiffies = jiffies; | |
2306 | for (res = 0, try = 0; try <= adapter->retries; try++) { | |
2307 | res = adapter->algo->smbus_xfer(adapter, addr, flags, | |
2308 | read_write, command, | |
2309 | protocol, data); | |
2310 | if (res != -EAGAIN) | |
2311 | break; | |
2312 | if (time_after(jiffies, | |
2313 | orig_jiffies + adapter->timeout)) | |
2314 | break; | |
2315 | } | |
fe61e07e | 2316 | i2c_unlock_adapter(adapter); |
1da177e4 | 2317 | |
72fc2c7f LP |
2318 | if (res != -EOPNOTSUPP || !adapter->algo->master_xfer) |
2319 | return res; | |
2320 | /* | |
2321 | * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't | |
2322 | * implement native support for the SMBus operation. | |
2323 | */ | |
2324 | } | |
2325 | ||
2326 | return i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, | |
2327 | command, protocol, data); | |
1da177e4 | 2328 | } |
1da177e4 | 2329 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
2330 | |
2331 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
2332 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
2333 | MODULE_LICENSE("GPL"); |