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 | } | |
0001a0ca | 209 | EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery); |
5f9296ba VK |
210 | |
211 | int i2c_generic_gpio_recovery(struct i2c_adapter *adap) | |
212 | { | |
213 | int ret; | |
214 | ||
215 | ret = i2c_get_gpios_for_recovery(adap); | |
216 | if (ret) | |
217 | return ret; | |
218 | ||
219 | ret = i2c_generic_recovery(adap); | |
220 | i2c_put_gpios_for_recovery(adap); | |
221 | ||
222 | return ret; | |
223 | } | |
0001a0ca | 224 | EXPORT_SYMBOL_GPL(i2c_generic_gpio_recovery); |
5f9296ba VK |
225 | |
226 | int i2c_recover_bus(struct i2c_adapter *adap) | |
227 | { | |
228 | if (!adap->bus_recovery_info) | |
229 | return -EOPNOTSUPP; | |
230 | ||
231 | dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); | |
232 | return adap->bus_recovery_info->recover_bus(adap); | |
233 | } | |
0001a0ca | 234 | EXPORT_SYMBOL_GPL(i2c_recover_bus); |
5f9296ba | 235 | |
f37dd80a | 236 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 237 | { |
51298d12 JD |
238 | struct i2c_client *client = i2c_verify_client(dev); |
239 | struct i2c_driver *driver; | |
50c3304a | 240 | int status; |
7b4fbc50 | 241 | |
51298d12 JD |
242 | if (!client) |
243 | return 0; | |
244 | ||
245 | driver = to_i2c_driver(dev->driver); | |
e0457442 | 246 | if (!driver->probe || !driver->id_table) |
7b4fbc50 DB |
247 | return -ENODEV; |
248 | client->driver = driver; | |
ee35425c MP |
249 | if (!device_can_wakeup(&client->dev)) |
250 | device_init_wakeup(&client->dev, | |
251 | client->flags & I2C_CLIENT_WAKE); | |
7b4fbc50 | 252 | dev_dbg(dev, "probe\n"); |
d2653e92 | 253 | |
e0457442 | 254 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
e4a7b9b0 | 255 | if (status) { |
50c3304a | 256 | client->driver = NULL; |
e4a7b9b0 WS |
257 | i2c_set_clientdata(client, NULL); |
258 | } | |
50c3304a | 259 | return status; |
f37dd80a | 260 | } |
1da177e4 | 261 | |
f37dd80a DB |
262 | static int i2c_device_remove(struct device *dev) |
263 | { | |
51298d12 | 264 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 DB |
265 | struct i2c_driver *driver; |
266 | int status; | |
267 | ||
51298d12 | 268 | if (!client || !dev->driver) |
a1d9e6e4 DB |
269 | return 0; |
270 | ||
271 | driver = to_i2c_driver(dev->driver); | |
272 | if (driver->remove) { | |
273 | dev_dbg(dev, "remove\n"); | |
274 | status = driver->remove(client); | |
275 | } else { | |
276 | dev->driver = NULL; | |
277 | status = 0; | |
278 | } | |
e4a7b9b0 | 279 | if (status == 0) { |
a1d9e6e4 | 280 | client->driver = NULL; |
e4a7b9b0 WS |
281 | i2c_set_clientdata(client, NULL); |
282 | } | |
a1d9e6e4 | 283 | return status; |
1da177e4 LT |
284 | } |
285 | ||
f37dd80a | 286 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 287 | { |
51298d12 | 288 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
289 | struct i2c_driver *driver; |
290 | ||
51298d12 | 291 | if (!client || !dev->driver) |
f37dd80a DB |
292 | return; |
293 | driver = to_i2c_driver(dev->driver); | |
294 | if (driver->shutdown) | |
51298d12 | 295 | driver->shutdown(client); |
1da177e4 LT |
296 | } |
297 | ||
2f60ba70 RW |
298 | #ifdef CONFIG_PM_SLEEP |
299 | static int i2c_legacy_suspend(struct device *dev, pm_message_t mesg) | |
54067ee2 | 300 | { |
2f60ba70 RW |
301 | struct i2c_client *client = i2c_verify_client(dev); |
302 | struct i2c_driver *driver; | |
54067ee2 | 303 | |
2f60ba70 | 304 | if (!client || !dev->driver) |
54067ee2 | 305 | return 0; |
2f60ba70 RW |
306 | driver = to_i2c_driver(dev->driver); |
307 | if (!driver->suspend) | |
54067ee2 | 308 | return 0; |
2f60ba70 | 309 | return driver->suspend(client, mesg); |
54067ee2 | 310 | } |
311 | ||
2f60ba70 | 312 | static int i2c_legacy_resume(struct device *dev) |
54067ee2 | 313 | { |
2f60ba70 RW |
314 | struct i2c_client *client = i2c_verify_client(dev); |
315 | struct i2c_driver *driver; | |
54067ee2 | 316 | |
2f60ba70 | 317 | if (!client || !dev->driver) |
54067ee2 | 318 | return 0; |
2f60ba70 RW |
319 | driver = to_i2c_driver(dev->driver); |
320 | if (!driver->resume) | |
54067ee2 | 321 | return 0; |
2f60ba70 | 322 | return driver->resume(client); |
54067ee2 | 323 | } |
54067ee2 | 324 | |
2f60ba70 | 325 | static int i2c_device_pm_suspend(struct device *dev) |
6de468ae | 326 | { |
2f60ba70 | 327 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 328 | |
d529de29 MB |
329 | if (pm) |
330 | return pm_generic_suspend(dev); | |
331 | else | |
332 | return i2c_legacy_suspend(dev, PMSG_SUSPEND); | |
6de468ae MB |
333 | } |
334 | ||
2f60ba70 | 335 | static int i2c_device_pm_resume(struct device *dev) |
6de468ae | 336 | { |
2f60ba70 | 337 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 338 | |
2f60ba70 | 339 | if (pm) |
d529de29 | 340 | return pm_generic_resume(dev); |
2f60ba70 | 341 | else |
d529de29 | 342 | return i2c_legacy_resume(dev); |
6de468ae | 343 | } |
6de468ae | 344 | |
2f60ba70 | 345 | static int i2c_device_pm_freeze(struct device *dev) |
1da177e4 | 346 | { |
2f60ba70 | 347 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 348 | |
d529de29 MB |
349 | if (pm) |
350 | return pm_generic_freeze(dev); | |
351 | else | |
352 | return i2c_legacy_suspend(dev, PMSG_FREEZE); | |
1da177e4 LT |
353 | } |
354 | ||
2f60ba70 | 355 | static int i2c_device_pm_thaw(struct device *dev) |
1da177e4 | 356 | { |
2f60ba70 | 357 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 358 | |
d529de29 MB |
359 | if (pm) |
360 | return pm_generic_thaw(dev); | |
361 | else | |
362 | return i2c_legacy_resume(dev); | |
2f60ba70 RW |
363 | } |
364 | ||
365 | static int i2c_device_pm_poweroff(struct device *dev) | |
366 | { | |
367 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
368 | ||
d529de29 MB |
369 | if (pm) |
370 | return pm_generic_poweroff(dev); | |
371 | else | |
372 | return i2c_legacy_suspend(dev, PMSG_HIBERNATE); | |
2f60ba70 RW |
373 | } |
374 | ||
375 | static int i2c_device_pm_restore(struct device *dev) | |
376 | { | |
377 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
2f60ba70 RW |
378 | |
379 | if (pm) | |
d529de29 | 380 | return pm_generic_restore(dev); |
2f60ba70 | 381 | else |
d529de29 | 382 | return i2c_legacy_resume(dev); |
1da177e4 | 383 | } |
2f60ba70 RW |
384 | #else /* !CONFIG_PM_SLEEP */ |
385 | #define i2c_device_pm_suspend NULL | |
386 | #define i2c_device_pm_resume NULL | |
387 | #define i2c_device_pm_freeze NULL | |
388 | #define i2c_device_pm_thaw NULL | |
389 | #define i2c_device_pm_poweroff NULL | |
390 | #define i2c_device_pm_restore NULL | |
391 | #endif /* !CONFIG_PM_SLEEP */ | |
1da177e4 | 392 | |
9c1600ed DB |
393 | static void i2c_client_dev_release(struct device *dev) |
394 | { | |
395 | kfree(to_i2c_client(dev)); | |
396 | } | |
397 | ||
09b8ce0a | 398 | static ssize_t |
4f8cf824 | 399 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 400 | { |
4f8cf824 JD |
401 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
402 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 DB |
403 | } |
404 | ||
09b8ce0a ZX |
405 | static ssize_t |
406 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
407 | { |
408 | struct i2c_client *client = to_i2c_client(dev); | |
eb8a7908 | 409 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
410 | } |
411 | ||
4f8cf824 | 412 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
51298d12 JD |
413 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
414 | ||
415 | static struct attribute *i2c_dev_attrs[] = { | |
416 | &dev_attr_name.attr, | |
7b4fbc50 | 417 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
418 | &dev_attr_modalias.attr, |
419 | NULL | |
420 | }; | |
421 | ||
422 | static struct attribute_group i2c_dev_attr_group = { | |
423 | .attrs = i2c_dev_attrs, | |
424 | }; | |
425 | ||
426 | static const struct attribute_group *i2c_dev_attr_groups[] = { | |
427 | &i2c_dev_attr_group, | |
428 | NULL | |
7b4fbc50 DB |
429 | }; |
430 | ||
0b2c3688 | 431 | static const struct dev_pm_ops i2c_device_pm_ops = { |
54067ee2 | 432 | .suspend = i2c_device_pm_suspend, |
433 | .resume = i2c_device_pm_resume, | |
2f60ba70 RW |
434 | .freeze = i2c_device_pm_freeze, |
435 | .thaw = i2c_device_pm_thaw, | |
436 | .poweroff = i2c_device_pm_poweroff, | |
437 | .restore = i2c_device_pm_restore, | |
438 | SET_RUNTIME_PM_OPS( | |
439 | pm_generic_runtime_suspend, | |
440 | pm_generic_runtime_resume, | |
441 | pm_generic_runtime_idle | |
442 | ) | |
54067ee2 | 443 | }; |
444 | ||
e9ca9eb9 | 445 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
446 | .name = "i2c", |
447 | .match = i2c_device_match, | |
448 | .probe = i2c_device_probe, | |
449 | .remove = i2c_device_remove, | |
450 | .shutdown = i2c_device_shutdown, | |
54067ee2 | 451 | .pm = &i2c_device_pm_ops, |
b864c7d5 | 452 | }; |
e9ca9eb9 | 453 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 454 | |
51298d12 JD |
455 | static struct device_type i2c_client_type = { |
456 | .groups = i2c_dev_attr_groups, | |
457 | .uevent = i2c_device_uevent, | |
458 | .release = i2c_client_dev_release, | |
459 | }; | |
460 | ||
9b766b81 DB |
461 | |
462 | /** | |
463 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
464 | * @dev: device, probably from some driver model iterator | |
465 | * | |
466 | * When traversing the driver model tree, perhaps using driver model | |
467 | * iterators like @device_for_each_child(), you can't assume very much | |
468 | * about the nodes you find. Use this function to avoid oopses caused | |
469 | * by wrongly treating some non-I2C device as an i2c_client. | |
470 | */ | |
471 | struct i2c_client *i2c_verify_client(struct device *dev) | |
472 | { | |
51298d12 | 473 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
474 | ? to_i2c_client(dev) |
475 | : NULL; | |
476 | } | |
477 | EXPORT_SYMBOL(i2c_verify_client); | |
478 | ||
479 | ||
3a89db5f | 480 | /* This is a permissive address validity check, I2C address map constraints |
25985edc | 481 | * are purposely not enforced, except for the general call address. */ |
3a89db5f JD |
482 | static int i2c_check_client_addr_validity(const struct i2c_client *client) |
483 | { | |
484 | if (client->flags & I2C_CLIENT_TEN) { | |
485 | /* 10-bit address, all values are valid */ | |
486 | if (client->addr > 0x3ff) | |
487 | return -EINVAL; | |
488 | } else { | |
489 | /* 7-bit address, reject the general call address */ | |
490 | if (client->addr == 0x00 || client->addr > 0x7f) | |
491 | return -EINVAL; | |
492 | } | |
493 | return 0; | |
494 | } | |
495 | ||
656b8761 JD |
496 | /* And this is a strict address validity check, used when probing. If a |
497 | * device uses a reserved address, then it shouldn't be probed. 7-bit | |
498 | * addressing is assumed, 10-bit address devices are rare and should be | |
499 | * explicitly enumerated. */ | |
500 | static int i2c_check_addr_validity(unsigned short addr) | |
501 | { | |
502 | /* | |
503 | * Reserved addresses per I2C specification: | |
504 | * 0x00 General call address / START byte | |
505 | * 0x01 CBUS address | |
506 | * 0x02 Reserved for different bus format | |
507 | * 0x03 Reserved for future purposes | |
508 | * 0x04-0x07 Hs-mode master code | |
509 | * 0x78-0x7b 10-bit slave addressing | |
510 | * 0x7c-0x7f Reserved for future purposes | |
511 | */ | |
512 | if (addr < 0x08 || addr > 0x77) | |
513 | return -EINVAL; | |
514 | return 0; | |
515 | } | |
516 | ||
3b5f794b JD |
517 | static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
518 | { | |
519 | struct i2c_client *client = i2c_verify_client(dev); | |
520 | int addr = *(int *)addrp; | |
521 | ||
522 | if (client && client->addr == addr) | |
523 | return -EBUSY; | |
524 | return 0; | |
525 | } | |
526 | ||
0826374b ML |
527 | /* walk up mux tree */ |
528 | static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
529 | { | |
97cc4d49 | 530 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
531 | int result; |
532 | ||
533 | result = device_for_each_child(&adapter->dev, &addr, | |
534 | __i2c_check_addr_busy); | |
535 | ||
97cc4d49 JD |
536 | if (!result && parent) |
537 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
538 | |
539 | return result; | |
540 | } | |
541 | ||
542 | /* recurse down mux tree */ | |
543 | static int i2c_check_mux_children(struct device *dev, void *addrp) | |
544 | { | |
545 | int result; | |
546 | ||
547 | if (dev->type == &i2c_adapter_type) | |
548 | result = device_for_each_child(dev, addrp, | |
549 | i2c_check_mux_children); | |
550 | else | |
551 | result = __i2c_check_addr_busy(dev, addrp); | |
552 | ||
553 | return result; | |
554 | } | |
555 | ||
3b5f794b JD |
556 | static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) |
557 | { | |
97cc4d49 | 558 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
559 | int result = 0; |
560 | ||
97cc4d49 JD |
561 | if (parent) |
562 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
563 | |
564 | if (!result) | |
565 | result = device_for_each_child(&adapter->dev, &addr, | |
566 | i2c_check_mux_children); | |
567 | ||
568 | return result; | |
3b5f794b JD |
569 | } |
570 | ||
fe61e07e JD |
571 | /** |
572 | * i2c_lock_adapter - Get exclusive access to an I2C bus segment | |
573 | * @adapter: Target I2C bus segment | |
574 | */ | |
575 | void i2c_lock_adapter(struct i2c_adapter *adapter) | |
576 | { | |
97cc4d49 JD |
577 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
578 | ||
579 | if (parent) | |
580 | i2c_lock_adapter(parent); | |
0826374b ML |
581 | else |
582 | rt_mutex_lock(&adapter->bus_lock); | |
fe61e07e JD |
583 | } |
584 | EXPORT_SYMBOL_GPL(i2c_lock_adapter); | |
585 | ||
586 | /** | |
587 | * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment | |
588 | * @adapter: Target I2C bus segment | |
589 | */ | |
590 | static int i2c_trylock_adapter(struct i2c_adapter *adapter) | |
591 | { | |
97cc4d49 JD |
592 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
593 | ||
594 | if (parent) | |
595 | return i2c_trylock_adapter(parent); | |
0826374b ML |
596 | else |
597 | return rt_mutex_trylock(&adapter->bus_lock); | |
fe61e07e JD |
598 | } |
599 | ||
600 | /** | |
601 | * i2c_unlock_adapter - Release exclusive access to an I2C bus segment | |
602 | * @adapter: Target I2C bus segment | |
603 | */ | |
604 | void i2c_unlock_adapter(struct i2c_adapter *adapter) | |
605 | { | |
97cc4d49 JD |
606 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
607 | ||
608 | if (parent) | |
609 | i2c_unlock_adapter(parent); | |
0826374b ML |
610 | else |
611 | rt_mutex_unlock(&adapter->bus_lock); | |
fe61e07e JD |
612 | } |
613 | EXPORT_SYMBOL_GPL(i2c_unlock_adapter); | |
614 | ||
9c1600ed | 615 | /** |
f8a227e8 | 616 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
617 | * @adap: the adapter managing the device |
618 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 619 | * Context: can sleep |
9c1600ed | 620 | * |
f8a227e8 JD |
621 | * Create an i2c device. Binding is handled through driver model |
622 | * probe()/remove() methods. A driver may be bound to this device when we | |
623 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
624 | * load the driver module). This call is not appropriate for use by mainboard | |
625 | * initialization logic, which usually runs during an arch_initcall() long | |
626 | * before any i2c_adapter could exist. | |
9c1600ed DB |
627 | * |
628 | * This returns the new i2c client, which may be saved for later use with | |
629 | * i2c_unregister_device(); or NULL to indicate an error. | |
630 | */ | |
631 | struct i2c_client * | |
632 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
633 | { | |
634 | struct i2c_client *client; | |
635 | int status; | |
636 | ||
637 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
638 | if (!client) | |
639 | return NULL; | |
640 | ||
641 | client->adapter = adap; | |
642 | ||
643 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 644 | |
11f1f2af AV |
645 | if (info->archdata) |
646 | client->dev.archdata = *info->archdata; | |
647 | ||
ee35425c | 648 | client->flags = info->flags; |
9c1600ed DB |
649 | client->addr = info->addr; |
650 | client->irq = info->irq; | |
651 | ||
9c1600ed DB |
652 | strlcpy(client->name, info->type, sizeof(client->name)); |
653 | ||
3a89db5f JD |
654 | /* Check for address validity */ |
655 | status = i2c_check_client_addr_validity(client); | |
656 | if (status) { | |
657 | dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", | |
658 | client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); | |
659 | goto out_err_silent; | |
660 | } | |
661 | ||
f8a227e8 | 662 | /* Check for address business */ |
3b5f794b | 663 | status = i2c_check_addr_busy(adap, client->addr); |
f8a227e8 JD |
664 | if (status) |
665 | goto out_err; | |
666 | ||
667 | client->dev.parent = &client->adapter->dev; | |
668 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 669 | client->dev.type = &i2c_client_type; |
d12d42f7 | 670 | client->dev.of_node = info->of_node; |
907ddf89 | 671 | ACPI_HANDLE_SET(&client->dev, info->acpi_node.handle); |
f8a227e8 | 672 | |
cbb44514 | 673 | /* For 10-bit clients, add an arbitrary offset to avoid collisions */ |
f8a227e8 | 674 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), |
cbb44514 JD |
675 | client->addr | ((client->flags & I2C_CLIENT_TEN) |
676 | ? 0xa000 : 0)); | |
f8a227e8 JD |
677 | status = device_register(&client->dev); |
678 | if (status) | |
679 | goto out_err; | |
680 | ||
f8a227e8 JD |
681 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
682 | client->name, dev_name(&client->dev)); | |
683 | ||
9c1600ed | 684 | return client; |
f8a227e8 JD |
685 | |
686 | out_err: | |
687 | dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " | |
688 | "(%d)\n", client->name, client->addr, status); | |
3a89db5f | 689 | out_err_silent: |
f8a227e8 JD |
690 | kfree(client); |
691 | return NULL; | |
9c1600ed DB |
692 | } |
693 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
694 | ||
695 | ||
696 | /** | |
697 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
698 | * @client: value returned from i2c_new_device() | |
d64f73be | 699 | * Context: can sleep |
9c1600ed DB |
700 | */ |
701 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 702 | { |
a1d9e6e4 DB |
703 | device_unregister(&client->dev); |
704 | } | |
9c1600ed | 705 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
706 | |
707 | ||
60b129d7 JD |
708 | static const struct i2c_device_id dummy_id[] = { |
709 | { "dummy", 0 }, | |
710 | { }, | |
711 | }; | |
712 | ||
d2653e92 JD |
713 | static int dummy_probe(struct i2c_client *client, |
714 | const struct i2c_device_id *id) | |
715 | { | |
716 | return 0; | |
717 | } | |
718 | ||
719 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
720 | { |
721 | return 0; | |
722 | } | |
723 | ||
724 | static struct i2c_driver dummy_driver = { | |
725 | .driver.name = "dummy", | |
d2653e92 JD |
726 | .probe = dummy_probe, |
727 | .remove = dummy_remove, | |
60b129d7 | 728 | .id_table = dummy_id, |
e9f1373b DB |
729 | }; |
730 | ||
731 | /** | |
732 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
733 | * @adapter: the adapter managing the device | |
734 | * @address: seven bit address to be used | |
e9f1373b DB |
735 | * Context: can sleep |
736 | * | |
737 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
738 | * with devices that consume multiple addresses. Examples of such chips | |
739 | * include various EEPROMS (like 24c04 and 24c08 models). | |
740 | * | |
741 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
742 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
743 | * And second, this prevents the specified address from being bound to a | |
744 | * different driver. | |
745 | * | |
746 | * This returns the new i2c client, which should be saved for later use with | |
747 | * i2c_unregister_device(); or NULL to indicate an error. | |
748 | */ | |
09b8ce0a | 749 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
750 | { |
751 | struct i2c_board_info info = { | |
60b129d7 | 752 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
753 | }; |
754 | ||
e9f1373b DB |
755 | return i2c_new_device(adapter, &info); |
756 | } | |
757 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
758 | ||
f37dd80a DB |
759 | /* ------------------------------------------------------------------------- */ |
760 | ||
16ffadfc DB |
761 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
762 | ||
83eaaed0 | 763 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 764 | { |
ef2c8321 | 765 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
766 | complete(&adap->dev_released); |
767 | } | |
768 | ||
390946b1 JD |
769 | /* |
770 | * This function is only needed for mutex_lock_nested, so it is never | |
771 | * called unless locking correctness checking is enabled. Thus we | |
772 | * make it inline to avoid a compiler warning. That's what gcc ends up | |
773 | * doing anyway. | |
774 | */ | |
775 | static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) | |
776 | { | |
777 | unsigned int depth = 0; | |
778 | ||
779 | while ((adapter = i2c_parent_is_i2c_adapter(adapter))) | |
780 | depth++; | |
781 | ||
782 | return depth; | |
783 | } | |
784 | ||
99cd8e25 JD |
785 | /* |
786 | * Let users instantiate I2C devices through sysfs. This can be used when | |
787 | * platform initialization code doesn't contain the proper data for | |
788 | * whatever reason. Also useful for drivers that do device detection and | |
789 | * detection fails, either because the device uses an unexpected address, | |
790 | * or this is a compatible device with different ID register values. | |
791 | * | |
792 | * Parameter checking may look overzealous, but we really don't want | |
793 | * the user to provide incorrect parameters. | |
794 | */ | |
795 | static ssize_t | |
796 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
797 | const char *buf, size_t count) | |
798 | { | |
799 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
800 | struct i2c_board_info info; | |
801 | struct i2c_client *client; | |
802 | char *blank, end; | |
803 | int res; | |
804 | ||
99cd8e25 JD |
805 | memset(&info, 0, sizeof(struct i2c_board_info)); |
806 | ||
807 | blank = strchr(buf, ' '); | |
808 | if (!blank) { | |
809 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
810 | return -EINVAL; | |
811 | } | |
812 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
813 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
814 | return -EINVAL; | |
815 | } | |
816 | memcpy(info.type, buf, blank - buf); | |
817 | ||
818 | /* Parse remaining parameters, reject extra parameters */ | |
819 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
820 | if (res < 1) { | |
821 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
822 | return -EINVAL; | |
823 | } | |
824 | if (res > 1 && end != '\n') { | |
825 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
826 | return -EINVAL; | |
827 | } | |
828 | ||
99cd8e25 JD |
829 | client = i2c_new_device(adap, &info); |
830 | if (!client) | |
3a89db5f | 831 | return -EINVAL; |
99cd8e25 JD |
832 | |
833 | /* Keep track of the added device */ | |
dafc50d1 | 834 | mutex_lock(&adap->userspace_clients_lock); |
6629dcff | 835 | list_add_tail(&client->detected, &adap->userspace_clients); |
dafc50d1 | 836 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
837 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
838 | info.type, info.addr); | |
839 | ||
840 | return count; | |
841 | } | |
842 | ||
843 | /* | |
844 | * And of course let the users delete the devices they instantiated, if | |
845 | * they got it wrong. This interface can only be used to delete devices | |
846 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
847 | * don't delete devices to which some kernel code still has references. | |
848 | * | |
849 | * Parameter checking may look overzealous, but we really don't want | |
850 | * the user to delete the wrong device. | |
851 | */ | |
852 | static ssize_t | |
853 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
854 | const char *buf, size_t count) | |
855 | { | |
856 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
857 | struct i2c_client *client, *next; | |
858 | unsigned short addr; | |
859 | char end; | |
860 | int res; | |
861 | ||
862 | /* Parse parameters, reject extra parameters */ | |
863 | res = sscanf(buf, "%hi%c", &addr, &end); | |
864 | if (res < 1) { | |
865 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
866 | return -EINVAL; | |
867 | } | |
868 | if (res > 1 && end != '\n') { | |
869 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
870 | return -EINVAL; | |
871 | } | |
872 | ||
873 | /* Make sure the device was added through sysfs */ | |
874 | res = -ENOENT; | |
390946b1 JD |
875 | mutex_lock_nested(&adap->userspace_clients_lock, |
876 | i2c_adapter_depth(adap)); | |
6629dcff JD |
877 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
878 | detected) { | |
879 | if (client->addr == addr) { | |
99cd8e25 JD |
880 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
881 | "delete_device", client->name, client->addr); | |
882 | ||
883 | list_del(&client->detected); | |
884 | i2c_unregister_device(client); | |
885 | res = count; | |
886 | break; | |
887 | } | |
888 | } | |
dafc50d1 | 889 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
890 | |
891 | if (res < 0) | |
892 | dev_err(dev, "%s: Can't find device in list\n", | |
893 | "delete_device"); | |
894 | return res; | |
895 | } | |
896 | ||
4f8cf824 | 897 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
e9b526fe AS |
898 | static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, |
899 | i2c_sysfs_delete_device); | |
4f8cf824 JD |
900 | |
901 | static struct attribute *i2c_adapter_attrs[] = { | |
902 | &dev_attr_name.attr, | |
903 | &dev_attr_new_device.attr, | |
904 | &dev_attr_delete_device.attr, | |
905 | NULL | |
906 | }; | |
907 | ||
908 | static struct attribute_group i2c_adapter_attr_group = { | |
909 | .attrs = i2c_adapter_attrs, | |
910 | }; | |
911 | ||
912 | static const struct attribute_group *i2c_adapter_attr_groups[] = { | |
913 | &i2c_adapter_attr_group, | |
914 | NULL | |
16ffadfc | 915 | }; |
b119dc3f | 916 | |
0826374b | 917 | struct device_type i2c_adapter_type = { |
4f8cf824 JD |
918 | .groups = i2c_adapter_attr_groups, |
919 | .release = i2c_adapter_dev_release, | |
1da177e4 | 920 | }; |
0826374b | 921 | EXPORT_SYMBOL_GPL(i2c_adapter_type); |
1da177e4 | 922 | |
643dd09e SW |
923 | /** |
924 | * i2c_verify_adapter - return parameter as i2c_adapter or NULL | |
925 | * @dev: device, probably from some driver model iterator | |
926 | * | |
927 | * When traversing the driver model tree, perhaps using driver model | |
928 | * iterators like @device_for_each_child(), you can't assume very much | |
929 | * about the nodes you find. Use this function to avoid oopses caused | |
930 | * by wrongly treating some non-I2C device as an i2c_adapter. | |
931 | */ | |
932 | struct i2c_adapter *i2c_verify_adapter(struct device *dev) | |
933 | { | |
934 | return (dev->type == &i2c_adapter_type) | |
935 | ? to_i2c_adapter(dev) | |
936 | : NULL; | |
937 | } | |
938 | EXPORT_SYMBOL(i2c_verify_adapter); | |
939 | ||
2bb5095a JD |
940 | #ifdef CONFIG_I2C_COMPAT |
941 | static struct class_compat *i2c_adapter_compat_class; | |
942 | #endif | |
943 | ||
9c1600ed DB |
944 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
945 | { | |
946 | struct i2c_devinfo *devinfo; | |
947 | ||
f18c41da | 948 | down_read(&__i2c_board_lock); |
9c1600ed DB |
949 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
950 | if (devinfo->busnum == adapter->nr | |
951 | && !i2c_new_device(adapter, | |
952 | &devinfo->board_info)) | |
09b8ce0a ZX |
953 | dev_err(&adapter->dev, |
954 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
955 | devinfo->board_info.addr); |
956 | } | |
f18c41da | 957 | up_read(&__i2c_board_lock); |
9c1600ed DB |
958 | } |
959 | ||
69b0089a JD |
960 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
961 | struct i2c_adapter *adap) | |
026526f5 | 962 | { |
4735c98f JD |
963 | /* Detect supported devices on that bus, and instantiate them */ |
964 | i2c_detect(adap, driver); | |
965 | ||
966 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 | 967 | if (driver->attach_adapter) { |
a920ff41 JD |
968 | dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n", |
969 | driver->driver.name); | |
fe6fc258 JD |
970 | dev_warn(&adap->dev, "Please use another way to instantiate " |
971 | "your i2c_client\n"); | |
026526f5 JD |
972 | /* We ignore the return code; if it fails, too bad */ |
973 | driver->attach_adapter(adap); | |
974 | } | |
975 | return 0; | |
976 | } | |
977 | ||
69b0089a JD |
978 | static int __process_new_adapter(struct device_driver *d, void *data) |
979 | { | |
980 | return i2c_do_add_adapter(to_i2c_driver(d), data); | |
981 | } | |
982 | ||
6e13e641 | 983 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 984 | { |
d6703281 | 985 | int res = 0; |
1da177e4 | 986 | |
1d0b19c9 | 987 | /* Can't register until after driver model init */ |
35fc37f8 JD |
988 | if (unlikely(WARN_ON(!i2c_bus_type.p))) { |
989 | res = -EAGAIN; | |
990 | goto out_list; | |
991 | } | |
1d0b19c9 | 992 | |
2236baa7 JD |
993 | /* Sanity checks */ |
994 | if (unlikely(adap->name[0] == '\0')) { | |
995 | pr_err("i2c-core: Attempt to register an adapter with " | |
996 | "no name!\n"); | |
997 | return -EINVAL; | |
998 | } | |
999 | if (unlikely(!adap->algo)) { | |
1000 | pr_err("i2c-core: Attempt to register adapter '%s' with " | |
1001 | "no algo!\n", adap->name); | |
1002 | return -EINVAL; | |
1003 | } | |
1004 | ||
194684e5 | 1005 | rt_mutex_init(&adap->bus_lock); |
dafc50d1 | 1006 | mutex_init(&adap->userspace_clients_lock); |
6629dcff | 1007 | INIT_LIST_HEAD(&adap->userspace_clients); |
1da177e4 | 1008 | |
8fcfef6e JD |
1009 | /* Set default timeout to 1 second if not already set */ |
1010 | if (adap->timeout == 0) | |
1011 | adap->timeout = HZ; | |
1012 | ||
27d9c183 | 1013 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
1014 | adap->dev.bus = &i2c_bus_type; |
1015 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 JD |
1016 | res = device_register(&adap->dev); |
1017 | if (res) | |
1018 | goto out_list; | |
1da177e4 | 1019 | |
b6d7b3d1 JD |
1020 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
1021 | ||
2bb5095a JD |
1022 | #ifdef CONFIG_I2C_COMPAT |
1023 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
1024 | adap->dev.parent); | |
1025 | if (res) | |
1026 | dev_warn(&adap->dev, | |
1027 | "Failed to create compatibility class link\n"); | |
1028 | #endif | |
1029 | ||
5f9296ba VK |
1030 | /* bus recovery specific initialization */ |
1031 | if (adap->bus_recovery_info) { | |
1032 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
1033 | ||
1034 | if (!bri->recover_bus) { | |
1035 | dev_err(&adap->dev, "No recover_bus() found, not using recovery\n"); | |
1036 | adap->bus_recovery_info = NULL; | |
1037 | goto exit_recovery; | |
1038 | } | |
1039 | ||
1040 | /* Generic GPIO recovery */ | |
1041 | if (bri->recover_bus == i2c_generic_gpio_recovery) { | |
1042 | if (!gpio_is_valid(bri->scl_gpio)) { | |
1043 | dev_err(&adap->dev, "Invalid SCL gpio, not using recovery\n"); | |
1044 | adap->bus_recovery_info = NULL; | |
1045 | goto exit_recovery; | |
1046 | } | |
1047 | ||
1048 | if (gpio_is_valid(bri->sda_gpio)) | |
1049 | bri->get_sda = get_sda_gpio_value; | |
1050 | else | |
1051 | bri->get_sda = NULL; | |
1052 | ||
1053 | bri->get_scl = get_scl_gpio_value; | |
1054 | bri->set_scl = set_scl_gpio_value; | |
1055 | } else if (!bri->set_scl || !bri->get_scl) { | |
1056 | /* Generic SCL recovery */ | |
1057 | dev_err(&adap->dev, "No {get|set}_gpio() found, not using recovery\n"); | |
1058 | adap->bus_recovery_info = NULL; | |
1059 | } | |
1060 | } | |
1061 | ||
1062 | exit_recovery: | |
729d6dd5 | 1063 | /* create pre-declared device nodes */ |
6e13e641 DB |
1064 | if (adap->nr < __i2c_first_dynamic_bus_num) |
1065 | i2c_scan_static_board_info(adap); | |
1066 | ||
4735c98f | 1067 | /* Notify drivers */ |
35fc37f8 | 1068 | mutex_lock(&core_lock); |
d6703281 | 1069 | bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); |
caada32a | 1070 | mutex_unlock(&core_lock); |
35fc37f8 JD |
1071 | |
1072 | return 0; | |
b119c6c9 | 1073 | |
b119c6c9 | 1074 | out_list: |
35fc37f8 | 1075 | mutex_lock(&core_lock); |
b119c6c9 | 1076 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
1077 | mutex_unlock(&core_lock); |
1078 | return res; | |
1da177e4 LT |
1079 | } |
1080 | ||
ee5c2744 DA |
1081 | /** |
1082 | * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 | |
1083 | * @adap: the adapter to register (with adap->nr initialized) | |
1084 | * Context: can sleep | |
1085 | * | |
1086 | * See i2c_add_numbered_adapter() for details. | |
1087 | */ | |
1088 | static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1089 | { | |
1090 | int id; | |
1091 | ||
1092 | mutex_lock(&core_lock); | |
1093 | id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, | |
1094 | GFP_KERNEL); | |
1095 | mutex_unlock(&core_lock); | |
1096 | if (id < 0) | |
1097 | return id == -ENOSPC ? -EBUSY : id; | |
1098 | ||
1099 | return i2c_register_adapter(adap); | |
1100 | } | |
1101 | ||
6e13e641 DB |
1102 | /** |
1103 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
1104 | * @adapter: the adapter to add | |
d64f73be | 1105 | * Context: can sleep |
6e13e641 DB |
1106 | * |
1107 | * This routine is used to declare an I2C adapter when its bus number | |
ee5c2744 DA |
1108 | * doesn't matter or when its bus number is specified by an dt alias. |
1109 | * Examples of bases when the bus number doesn't matter: I2C adapters | |
1110 | * dynamically added by USB links or PCI plugin cards. | |
6e13e641 DB |
1111 | * |
1112 | * When this returns zero, a new bus number was allocated and stored | |
1113 | * in adap->nr, and the specified adapter became available for clients. | |
1114 | * Otherwise, a negative errno value is returned. | |
1115 | */ | |
1116 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
1117 | { | |
ee5c2744 | 1118 | struct device *dev = &adapter->dev; |
4ae42b0f | 1119 | int id; |
6e13e641 | 1120 | |
ee5c2744 DA |
1121 | if (dev->of_node) { |
1122 | id = of_alias_get_id(dev->of_node, "i2c"); | |
1123 | if (id >= 0) { | |
1124 | adapter->nr = id; | |
1125 | return __i2c_add_numbered_adapter(adapter); | |
1126 | } | |
1127 | } | |
1128 | ||
caada32a | 1129 | mutex_lock(&core_lock); |
4ae42b0f TH |
1130 | id = idr_alloc(&i2c_adapter_idr, adapter, |
1131 | __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); | |
caada32a | 1132 | mutex_unlock(&core_lock); |
4ae42b0f TH |
1133 | if (id < 0) |
1134 | return id; | |
6e13e641 DB |
1135 | |
1136 | adapter->nr = id; | |
4ae42b0f | 1137 | |
6e13e641 DB |
1138 | return i2c_register_adapter(adapter); |
1139 | } | |
1140 | EXPORT_SYMBOL(i2c_add_adapter); | |
1141 | ||
1142 | /** | |
1143 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
1144 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 1145 | * Context: can sleep |
6e13e641 DB |
1146 | * |
1147 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
1148 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
1149 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
1150 | * is used to properly configure I2C devices. |
1151 | * | |
488bf314 GL |
1152 | * If the requested bus number is set to -1, then this function will behave |
1153 | * identically to i2c_add_adapter, and will dynamically assign a bus number. | |
1154 | * | |
6e13e641 DB |
1155 | * If no devices have pre-been declared for this bus, then be sure to |
1156 | * register the adapter before any dynamically allocated ones. Otherwise | |
1157 | * the required bus ID may not be available. | |
1158 | * | |
1159 | * When this returns zero, the specified adapter became available for | |
1160 | * clients using the bus number provided in adap->nr. Also, the table | |
1161 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
1162 | * and the appropriate driver model device nodes are created. Otherwise, a | |
1163 | * negative errno value is returned. | |
1164 | */ | |
1165 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1166 | { | |
488bf314 GL |
1167 | if (adap->nr == -1) /* -1 means dynamically assign bus id */ |
1168 | return i2c_add_adapter(adap); | |
6e13e641 | 1169 | |
ee5c2744 | 1170 | return __i2c_add_numbered_adapter(adap); |
6e13e641 DB |
1171 | } |
1172 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
1173 | ||
19baba4c | 1174 | static void i2c_do_del_adapter(struct i2c_driver *driver, |
69b0089a | 1175 | struct i2c_adapter *adapter) |
026526f5 | 1176 | { |
4735c98f | 1177 | struct i2c_client *client, *_n; |
026526f5 | 1178 | |
acec211c JD |
1179 | /* Remove the devices we created ourselves as the result of hardware |
1180 | * probing (using a driver's detect method) */ | |
4735c98f JD |
1181 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
1182 | if (client->adapter == adapter) { | |
1183 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
1184 | client->name, client->addr); | |
1185 | list_del(&client->detected); | |
1186 | i2c_unregister_device(client); | |
1187 | } | |
1188 | } | |
026526f5 JD |
1189 | } |
1190 | ||
e549c2b5 | 1191 | static int __unregister_client(struct device *dev, void *dummy) |
5219bf88 JD |
1192 | { |
1193 | struct i2c_client *client = i2c_verify_client(dev); | |
1194 | if (client && strcmp(client->name, "dummy")) | |
1195 | i2c_unregister_device(client); | |
1196 | return 0; | |
1197 | } | |
1198 | ||
1199 | static int __unregister_dummy(struct device *dev, void *dummy) | |
e549c2b5 JD |
1200 | { |
1201 | struct i2c_client *client = i2c_verify_client(dev); | |
1202 | if (client) | |
1203 | i2c_unregister_device(client); | |
1204 | return 0; | |
1205 | } | |
1206 | ||
69b0089a JD |
1207 | static int __process_removed_adapter(struct device_driver *d, void *data) |
1208 | { | |
19baba4c LPC |
1209 | i2c_do_del_adapter(to_i2c_driver(d), data); |
1210 | return 0; | |
69b0089a JD |
1211 | } |
1212 | ||
d64f73be DB |
1213 | /** |
1214 | * i2c_del_adapter - unregister I2C adapter | |
1215 | * @adap: the adapter being unregistered | |
1216 | * Context: can sleep | |
1217 | * | |
1218 | * This unregisters an I2C adapter which was previously registered | |
1219 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
1220 | */ | |
71546300 | 1221 | void i2c_del_adapter(struct i2c_adapter *adap) |
1da177e4 | 1222 | { |
35fc37f8 | 1223 | struct i2c_adapter *found; |
bbd2d9c9 | 1224 | struct i2c_client *client, *next; |
1da177e4 LT |
1225 | |
1226 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
1227 | mutex_lock(&core_lock); |
1228 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
1229 | mutex_unlock(&core_lock); | |
1230 | if (found != adap) { | |
b6d7b3d1 JD |
1231 | pr_debug("i2c-core: attempting to delete unregistered " |
1232 | "adapter [%s]\n", adap->name); | |
71546300 | 1233 | return; |
1da177e4 LT |
1234 | } |
1235 | ||
026526f5 | 1236 | /* Tell drivers about this removal */ |
35fc37f8 | 1237 | mutex_lock(&core_lock); |
19baba4c | 1238 | bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 1239 | __process_removed_adapter); |
35fc37f8 | 1240 | mutex_unlock(&core_lock); |
1da177e4 | 1241 | |
bbd2d9c9 | 1242 | /* Remove devices instantiated from sysfs */ |
390946b1 JD |
1243 | mutex_lock_nested(&adap->userspace_clients_lock, |
1244 | i2c_adapter_depth(adap)); | |
6629dcff JD |
1245 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1246 | detected) { | |
1247 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, | |
1248 | client->addr); | |
1249 | list_del(&client->detected); | |
1250 | i2c_unregister_device(client); | |
bbd2d9c9 | 1251 | } |
dafc50d1 | 1252 | mutex_unlock(&adap->userspace_clients_lock); |
bbd2d9c9 | 1253 | |
e549c2b5 | 1254 | /* Detach any active clients. This can't fail, thus we do not |
5219bf88 JD |
1255 | * check the returned value. This is a two-pass process, because |
1256 | * we can't remove the dummy devices during the first pass: they | |
1257 | * could have been instantiated by real devices wishing to clean | |
1258 | * them up properly, so we give them a chance to do that first. */ | |
19baba4c LPC |
1259 | device_for_each_child(&adap->dev, NULL, __unregister_client); |
1260 | device_for_each_child(&adap->dev, NULL, __unregister_dummy); | |
1da177e4 | 1261 | |
2bb5095a JD |
1262 | #ifdef CONFIG_I2C_COMPAT |
1263 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
1264 | adap->dev.parent); | |
1265 | #endif | |
1266 | ||
c5567521 TLSC |
1267 | /* device name is gone after device_unregister */ |
1268 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); | |
1269 | ||
1da177e4 LT |
1270 | /* clean up the sysfs representation */ |
1271 | init_completion(&adap->dev_released); | |
1da177e4 | 1272 | device_unregister(&adap->dev); |
1da177e4 LT |
1273 | |
1274 | /* wait for sysfs to drop all references */ | |
1275 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 1276 | |
6e13e641 | 1277 | /* free bus id */ |
35fc37f8 | 1278 | mutex_lock(&core_lock); |
1da177e4 | 1279 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 1280 | mutex_unlock(&core_lock); |
1da177e4 | 1281 | |
bd4bc3db JD |
1282 | /* Clear the device structure in case this adapter is ever going to be |
1283 | added again */ | |
1284 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
1da177e4 | 1285 | } |
c0564606 | 1286 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 LT |
1287 | |
1288 | ||
7b4fbc50 DB |
1289 | /* ------------------------------------------------------------------------- */ |
1290 | ||
7ae31482 JD |
1291 | int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) |
1292 | { | |
1293 | int res; | |
1294 | ||
1295 | mutex_lock(&core_lock); | |
1296 | res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); | |
1297 | mutex_unlock(&core_lock); | |
1298 | ||
1299 | return res; | |
1300 | } | |
1301 | EXPORT_SYMBOL_GPL(i2c_for_each_dev); | |
1302 | ||
69b0089a | 1303 | static int __process_new_driver(struct device *dev, void *data) |
7f101a97 | 1304 | { |
4f8cf824 JD |
1305 | if (dev->type != &i2c_adapter_type) |
1306 | return 0; | |
69b0089a | 1307 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
7f101a97 DY |
1308 | } |
1309 | ||
7b4fbc50 DB |
1310 | /* |
1311 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 1312 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
1313 | */ |
1314 | ||
de59cf9e | 1315 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 1316 | { |
7eebcb7c | 1317 | int res; |
1da177e4 | 1318 | |
1d0b19c9 DB |
1319 | /* Can't register until after driver model init */ |
1320 | if (unlikely(WARN_ON(!i2c_bus_type.p))) | |
1321 | return -EAGAIN; | |
1322 | ||
1da177e4 | 1323 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 1324 | driver->driver.owner = owner; |
1da177e4 | 1325 | driver->driver.bus = &i2c_bus_type; |
3c5054e9 | 1326 | INIT_LIST_HEAD(&driver->clients); |
1da177e4 | 1327 | |
729d6dd5 | 1328 | /* When registration returns, the driver core |
6e13e641 DB |
1329 | * will have called probe() for all matching-but-unbound devices. |
1330 | */ | |
1da177e4 LT |
1331 | res = driver_register(&driver->driver); |
1332 | if (res) | |
7eebcb7c | 1333 | return res; |
438d6c2c | 1334 | |
f4e8db31 MB |
1335 | /* Drivers should switch to dev_pm_ops instead. */ |
1336 | if (driver->suspend) | |
1337 | pr_warn("i2c-core: driver [%s] using legacy suspend method\n", | |
1338 | driver->driver.name); | |
1339 | if (driver->resume) | |
1340 | pr_warn("i2c-core: driver [%s] using legacy resume method\n", | |
1341 | driver->driver.name); | |
1342 | ||
35d8b2e6 | 1343 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 1344 | |
4735c98f | 1345 | /* Walk the adapters that are already present */ |
7ae31482 | 1346 | i2c_for_each_dev(driver, __process_new_driver); |
35fc37f8 | 1347 | |
7f101a97 DY |
1348 | return 0; |
1349 | } | |
1350 | EXPORT_SYMBOL(i2c_register_driver); | |
1351 | ||
69b0089a | 1352 | static int __process_removed_driver(struct device *dev, void *data) |
7f101a97 | 1353 | { |
19baba4c LPC |
1354 | if (dev->type == &i2c_adapter_type) |
1355 | i2c_do_del_adapter(data, to_i2c_adapter(dev)); | |
1356 | return 0; | |
1da177e4 LT |
1357 | } |
1358 | ||
a1d9e6e4 DB |
1359 | /** |
1360 | * i2c_del_driver - unregister I2C driver | |
1361 | * @driver: the driver being unregistered | |
d64f73be | 1362 | * Context: can sleep |
a1d9e6e4 | 1363 | */ |
b3e82096 | 1364 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 1365 | { |
7ae31482 | 1366 | i2c_for_each_dev(driver, __process_removed_driver); |
1da177e4 LT |
1367 | |
1368 | driver_unregister(&driver->driver); | |
35d8b2e6 | 1369 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 1370 | } |
c0564606 | 1371 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 1372 | |
7b4fbc50 DB |
1373 | /* ------------------------------------------------------------------------- */ |
1374 | ||
e48d3319 JD |
1375 | /** |
1376 | * i2c_use_client - increments the reference count of the i2c client structure | |
1377 | * @client: the client being referenced | |
1378 | * | |
1379 | * Each live reference to a client should be refcounted. The driver model does | |
1380 | * that automatically as part of driver binding, so that most drivers don't | |
1381 | * need to do this explicitly: they hold a reference until they're unbound | |
1382 | * from the device. | |
1383 | * | |
1384 | * A pointer to the client with the incremented reference counter is returned. | |
1385 | */ | |
1386 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 1387 | { |
6ea438ec DB |
1388 | if (client && get_device(&client->dev)) |
1389 | return client; | |
1390 | return NULL; | |
1da177e4 | 1391 | } |
c0564606 | 1392 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 1393 | |
e48d3319 JD |
1394 | /** |
1395 | * i2c_release_client - release a use of the i2c client structure | |
1396 | * @client: the client being no longer referenced | |
1397 | * | |
1398 | * Must be called when a user of a client is finished with it. | |
1399 | */ | |
1400 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 1401 | { |
6ea438ec DB |
1402 | if (client) |
1403 | put_device(&client->dev); | |
1da177e4 | 1404 | } |
c0564606 | 1405 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 1406 | |
9b766b81 DB |
1407 | struct i2c_cmd_arg { |
1408 | unsigned cmd; | |
1409 | void *arg; | |
1410 | }; | |
1411 | ||
1412 | static int i2c_cmd(struct device *dev, void *_arg) | |
1413 | { | |
1414 | struct i2c_client *client = i2c_verify_client(dev); | |
1415 | struct i2c_cmd_arg *arg = _arg; | |
1416 | ||
1417 | if (client && client->driver && client->driver->command) | |
1418 | client->driver->command(client, arg->cmd, arg->arg); | |
1419 | return 0; | |
1420 | } | |
1421 | ||
1da177e4 LT |
1422 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
1423 | { | |
9b766b81 | 1424 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 1425 | |
9b766b81 DB |
1426 | cmd_arg.cmd = cmd; |
1427 | cmd_arg.arg = arg; | |
1428 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 1429 | } |
c0564606 | 1430 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
1431 | |
1432 | static int __init i2c_init(void) | |
1433 | { | |
1434 | int retval; | |
1435 | ||
1436 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
1437 | if (retval) |
1438 | return retval; | |
2bb5095a JD |
1439 | #ifdef CONFIG_I2C_COMPAT |
1440 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
1441 | if (!i2c_adapter_compat_class) { | |
1442 | retval = -ENOMEM; | |
1443 | goto bus_err; | |
1444 | } | |
1445 | #endif | |
e9f1373b DB |
1446 | retval = i2c_add_driver(&dummy_driver); |
1447 | if (retval) | |
2bb5095a | 1448 | goto class_err; |
e9f1373b DB |
1449 | return 0; |
1450 | ||
2bb5095a JD |
1451 | class_err: |
1452 | #ifdef CONFIG_I2C_COMPAT | |
1453 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 1454 | bus_err: |
2bb5095a | 1455 | #endif |
e9f1373b DB |
1456 | bus_unregister(&i2c_bus_type); |
1457 | return retval; | |
1da177e4 LT |
1458 | } |
1459 | ||
1460 | static void __exit i2c_exit(void) | |
1461 | { | |
e9f1373b | 1462 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
1463 | #ifdef CONFIG_I2C_COMPAT |
1464 | class_compat_unregister(i2c_adapter_compat_class); | |
1465 | #endif | |
1da177e4 LT |
1466 | bus_unregister(&i2c_bus_type); |
1467 | } | |
1468 | ||
a10f9e7c DB |
1469 | /* We must initialize early, because some subsystems register i2c drivers |
1470 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1471 | */ | |
1472 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1473 | module_exit(i2c_exit); |
1474 | ||
1475 | /* ---------------------------------------------------- | |
1476 | * the functional interface to the i2c busses. | |
1477 | * ---------------------------------------------------- | |
1478 | */ | |
1479 | ||
b37d2a3a JD |
1480 | /** |
1481 | * __i2c_transfer - unlocked flavor of i2c_transfer | |
1482 | * @adap: Handle to I2C bus | |
1483 | * @msgs: One or more messages to execute before STOP is issued to | |
1484 | * terminate the operation; each message begins with a START. | |
1485 | * @num: Number of messages to be executed. | |
1486 | * | |
1487 | * Returns negative errno, else the number of messages executed. | |
1488 | * | |
1489 | * Adapter lock must be held when calling this function. No debug logging | |
1490 | * takes place. adap->algo->master_xfer existence isn't checked. | |
1491 | */ | |
1492 | int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
1493 | { | |
1494 | unsigned long orig_jiffies; | |
1495 | int ret, try; | |
1496 | ||
1497 | /* Retry automatically on arbitration loss */ | |
1498 | orig_jiffies = jiffies; | |
1499 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
1500 | ret = adap->algo->master_xfer(adap, msgs, num); | |
1501 | if (ret != -EAGAIN) | |
1502 | break; | |
1503 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
1504 | break; | |
1505 | } | |
1506 | ||
1507 | return ret; | |
1508 | } | |
1509 | EXPORT_SYMBOL(__i2c_transfer); | |
1510 | ||
a1cdedac DB |
1511 | /** |
1512 | * i2c_transfer - execute a single or combined I2C message | |
1513 | * @adap: Handle to I2C bus | |
1514 | * @msgs: One or more messages to execute before STOP is issued to | |
1515 | * terminate the operation; each message begins with a START. | |
1516 | * @num: Number of messages to be executed. | |
1517 | * | |
1518 | * Returns negative errno, else the number of messages executed. | |
1519 | * | |
1520 | * Note that there is no requirement that each message be sent to | |
1521 | * the same slave address, although that is the most common model. | |
1522 | */ | |
09b8ce0a | 1523 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 1524 | { |
b37d2a3a | 1525 | int ret; |
1da177e4 | 1526 | |
a1cdedac DB |
1527 | /* REVISIT the fault reporting model here is weak: |
1528 | * | |
1529 | * - When we get an error after receiving N bytes from a slave, | |
1530 | * there is no way to report "N". | |
1531 | * | |
1532 | * - When we get a NAK after transmitting N bytes to a slave, | |
1533 | * there is no way to report "N" ... or to let the master | |
1534 | * continue executing the rest of this combined message, if | |
1535 | * that's the appropriate response. | |
1536 | * | |
1537 | * - When for example "num" is two and we successfully complete | |
1538 | * the first message but get an error part way through the | |
1539 | * second, it's unclear whether that should be reported as | |
1540 | * one (discarding status on the second message) or errno | |
1541 | * (discarding status on the first one). | |
1542 | */ | |
1543 | ||
1da177e4 LT |
1544 | if (adap->algo->master_xfer) { |
1545 | #ifdef DEBUG | |
1546 | for (ret = 0; ret < num; ret++) { | |
1547 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
1548 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
1549 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
1550 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
1551 | } |
1552 | #endif | |
1553 | ||
cea443a8 | 1554 | if (in_atomic() || irqs_disabled()) { |
fe61e07e | 1555 | ret = i2c_trylock_adapter(adap); |
cea443a8 MR |
1556 | if (!ret) |
1557 | /* I2C activity is ongoing. */ | |
1558 | return -EAGAIN; | |
1559 | } else { | |
fe61e07e | 1560 | i2c_lock_adapter(adap); |
cea443a8 MR |
1561 | } |
1562 | ||
b37d2a3a | 1563 | ret = __i2c_transfer(adap, msgs, num); |
fe61e07e | 1564 | i2c_unlock_adapter(adap); |
1da177e4 LT |
1565 | |
1566 | return ret; | |
1567 | } else { | |
1568 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1569 | return -EOPNOTSUPP; |
1da177e4 LT |
1570 | } |
1571 | } | |
c0564606 | 1572 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1573 | |
a1cdedac DB |
1574 | /** |
1575 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1576 | * @client: Handle to slave device | |
1577 | * @buf: Data that will be written to the slave | |
0c43ea54 | 1578 | * @count: How many bytes to write, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1579 | * |
1580 | * Returns negative errno, or else the number of bytes written. | |
1581 | */ | |
0cc43a18 | 1582 | int i2c_master_send(const struct i2c_client *client, const char *buf, int count) |
1da177e4 LT |
1583 | { |
1584 | int ret; | |
7225acf4 | 1585 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1586 | struct i2c_msg msg; |
1587 | ||
815f55f2 JD |
1588 | msg.addr = client->addr; |
1589 | msg.flags = client->flags & I2C_M_TEN; | |
1590 | msg.len = count; | |
1591 | msg.buf = (char *)buf; | |
6fa3eb70 S |
1592 | #ifdef USE_I2C_MTK_EXT |
1593 | msg.timing = client->timing; | |
1594 | msg.ext_flag = client->ext_flag; | |
1595 | #endif | |
815f55f2 | 1596 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1597 | |
834aa6f3 WS |
1598 | /* |
1599 | * If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1600 | * transmitted, else error code. | |
1601 | */ | |
815f55f2 | 1602 | return (ret == 1) ? count : ret; |
1da177e4 | 1603 | } |
c0564606 | 1604 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1605 | |
a1cdedac DB |
1606 | /** |
1607 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1608 | * @client: Handle to slave device | |
1609 | * @buf: Where to store data read from slave | |
0c43ea54 | 1610 | * @count: How many bytes to read, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1611 | * |
1612 | * Returns negative errno, or else the number of bytes read. | |
1613 | */ | |
0cc43a18 | 1614 | int i2c_master_recv(const struct i2c_client *client, char *buf, int count) |
1da177e4 | 1615 | { |
7225acf4 | 1616 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1617 | struct i2c_msg msg; |
1618 | int ret; | |
815f55f2 JD |
1619 | |
1620 | msg.addr = client->addr; | |
1621 | msg.flags = client->flags & I2C_M_TEN; | |
1622 | msg.flags |= I2C_M_RD; | |
1623 | msg.len = count; | |
1624 | msg.buf = buf; | |
6fa3eb70 S |
1625 | #ifdef USE_I2C_MTK_EXT |
1626 | msg.timing = client->timing; | |
1627 | msg.ext_flag = client->ext_flag; | |
1628 | #endif | |
815f55f2 JD |
1629 | ret = i2c_transfer(adap, &msg, 1); |
1630 | ||
834aa6f3 WS |
1631 | /* |
1632 | * If everything went ok (i.e. 1 msg received), return #bytes received, | |
1633 | * else error code. | |
1634 | */ | |
815f55f2 | 1635 | return (ret == 1) ? count : ret; |
1da177e4 | 1636 | } |
c0564606 | 1637 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1638 | |
6fa3eb70 S |
1639 | #ifdef USE_I2C_MTK_EXT |
1640 | ||
1641 | /** | |
1642 | * mt_i2c_master_send - issue a single I2C message in master transmit mode | |
1643 | * @client: Handle to slave device | |
1644 | * @buf: Data that will be written to the slave | |
1645 | * @count: How many bytes to write, must be less than 64k since msg.len is u16 | |
1646 | * @ext_flag: Controller special flags, for example, if you want using DMA, ext_flag |= I2C_DMA_FLAG. | |
1647 | * is the same to client->ext_flag | |
1648 | * | |
1649 | * Returns negative errno, or else the number of bytes written. | |
1650 | */ | |
1651 | int mt_i2c_master_send(const struct i2c_client *client, const char *buf, int count, u32 ext_flag) | |
1652 | { | |
1653 | int ret; | |
1654 | struct i2c_adapter *adap = client->adapter; | |
1655 | struct i2c_msg msg; | |
1656 | ||
1657 | msg.addr = client->addr; | |
1658 | msg.flags = client->flags & I2C_M_TEN; | |
1659 | msg.timing = client->timing; | |
1660 | msg.len = count; | |
1661 | msg.buf = (char *)buf; | |
1662 | msg.ext_flag = ext_flag; | |
1663 | ret = i2c_transfer(adap, &msg, 1); | |
1664 | ||
1665 | /* | |
1666 | * If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1667 | * transmitted, else error code. | |
1668 | */ | |
1669 | return (ret == 1) ? count : ret; | |
1670 | } | |
1671 | EXPORT_SYMBOL(mt_i2c_master_send); | |
1672 | ||
1673 | /** | |
1674 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1675 | * @client: Handle to slave device | |
1676 | * @buf: Where to store data read from slave | |
1677 | * @count: How many bytes to read, must be less than 64k since msg.len is u16 | |
1678 | * @ext_flag: Controller special flags, for example, if you want using DMA, ext_flag |= I2C_DMA_FLAG. | |
1679 | * is the same to client->ext_flag | |
1680 | * | |
1681 | * Returns negative errno, or else the number of bytes read. | |
1682 | */ | |
1683 | int mt_i2c_master_recv(const struct i2c_client *client, char *buf, int count, u32 ext_flag) | |
1684 | { | |
1685 | struct i2c_adapter *adap = client->adapter; | |
1686 | struct i2c_msg msg; | |
1687 | int ret; | |
1688 | ||
1689 | msg.addr = client->addr; | |
1690 | msg.flags = client->flags & I2C_M_TEN; | |
1691 | msg.flags |= I2C_M_RD; | |
1692 | msg.timing = client->timing; | |
1693 | msg.len = count; | |
1694 | msg.buf = buf; | |
1695 | msg.ext_flag = ext_flag; | |
1696 | ret = i2c_transfer(adap, &msg, 1); | |
1697 | ||
1698 | /* | |
1699 | * If everything went ok (i.e. 1 msg received), return #bytes received, | |
1700 | * else error code. | |
1701 | */ | |
1702 | return (ret == 1) ? count : ret; | |
1703 | } | |
1704 | EXPORT_SYMBOL(mt_i2c_master_recv); | |
1705 | #endif | |
1da177e4 LT |
1706 | /* ---------------------------------------------------- |
1707 | * the i2c address scanning function | |
1708 | * Will not work for 10-bit addresses! | |
1709 | * ---------------------------------------------------- | |
1710 | */ | |
1da177e4 | 1711 | |
63e4e802 JD |
1712 | /* |
1713 | * Legacy default probe function, mostly relevant for SMBus. The default | |
1714 | * probe method is a quick write, but it is known to corrupt the 24RF08 | |
1715 | * EEPROMs due to a state machine bug, and could also irreversibly | |
1716 | * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, | |
1717 | * we use a short byte read instead. Also, some bus drivers don't implement | |
1718 | * quick write, so we fallback to a byte read in that case too. | |
1719 | * On x86, there is another special case for FSC hardware monitoring chips, | |
1720 | * which want regular byte reads (address 0x73.) Fortunately, these are the | |
1721 | * only known chips using this I2C address on PC hardware. | |
1722 | * Returns 1 if probe succeeded, 0 if not. | |
1723 | */ | |
1724 | static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) | |
1725 | { | |
1726 | int err; | |
1727 | union i2c_smbus_data dummy; | |
1728 | ||
1729 | #ifdef CONFIG_X86 | |
1730 | if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) | |
1731 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) | |
1732 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1733 | I2C_SMBUS_BYTE_DATA, &dummy); | |
1734 | else | |
1735 | #endif | |
8031d79b JD |
1736 | if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) |
1737 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) | |
63e4e802 JD |
1738 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, |
1739 | I2C_SMBUS_QUICK, NULL); | |
8031d79b JD |
1740 | else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) |
1741 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1742 | I2C_SMBUS_BYTE, &dummy); | |
1743 | else { | |
1744 | dev_warn(&adap->dev, "No suitable probing method supported\n"); | |
1745 | err = -EOPNOTSUPP; | |
1746 | } | |
63e4e802 JD |
1747 | |
1748 | return err >= 0; | |
1749 | } | |
1750 | ||
ccfbbd08 | 1751 | static int i2c_detect_address(struct i2c_client *temp_client, |
4735c98f JD |
1752 | struct i2c_driver *driver) |
1753 | { | |
1754 | struct i2c_board_info info; | |
1755 | struct i2c_adapter *adapter = temp_client->adapter; | |
1756 | int addr = temp_client->addr; | |
1757 | int err; | |
1758 | ||
1759 | /* Make sure the address is valid */ | |
656b8761 JD |
1760 | err = i2c_check_addr_validity(addr); |
1761 | if (err) { | |
4735c98f JD |
1762 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
1763 | addr); | |
656b8761 | 1764 | return err; |
4735c98f JD |
1765 | } |
1766 | ||
1767 | /* Skip if already in use */ | |
3b5f794b | 1768 | if (i2c_check_addr_busy(adapter, addr)) |
4735c98f JD |
1769 | return 0; |
1770 | ||
ccfbbd08 | 1771 | /* Make sure there is something at this address */ |
63e4e802 JD |
1772 | if (!i2c_default_probe(adapter, addr)) |
1773 | return 0; | |
4735c98f JD |
1774 | |
1775 | /* Finally call the custom detection function */ | |
1776 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
1777 | info.addr = addr; | |
310ec792 | 1778 | err = driver->detect(temp_client, &info); |
4735c98f JD |
1779 | if (err) { |
1780 | /* -ENODEV is returned if the detection fails. We catch it | |
1781 | here as this isn't an error. */ | |
1782 | return err == -ENODEV ? 0 : err; | |
1783 | } | |
1784 | ||
1785 | /* Consistency check */ | |
1786 | if (info.type[0] == '\0') { | |
1787 | dev_err(&adapter->dev, "%s detection function provided " | |
1788 | "no name for 0x%x\n", driver->driver.name, | |
1789 | addr); | |
1790 | } else { | |
1791 | struct i2c_client *client; | |
1792 | ||
1793 | /* Detection succeeded, instantiate the device */ | |
1794 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", | |
1795 | info.type, info.addr); | |
1796 | client = i2c_new_device(adapter, &info); | |
1797 | if (client) | |
1798 | list_add_tail(&client->detected, &driver->clients); | |
1799 | else | |
1800 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
1801 | info.type, info.addr); | |
1802 | } | |
1803 | return 0; | |
1804 | } | |
1805 | ||
1806 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
1807 | { | |
c3813d6a | 1808 | const unsigned short *address_list; |
4735c98f JD |
1809 | struct i2c_client *temp_client; |
1810 | int i, err = 0; | |
1811 | int adap_id = i2c_adapter_id(adapter); | |
1812 | ||
c3813d6a JD |
1813 | address_list = driver->address_list; |
1814 | if (!driver->detect || !address_list) | |
4735c98f JD |
1815 | return 0; |
1816 | ||
51b54ba9 JD |
1817 | /* Stop here if the classes do not match */ |
1818 | if (!(adapter->class & driver->class)) | |
1819 | return 0; | |
1820 | ||
4735c98f JD |
1821 | /* Set up a temporary client to help detect callback */ |
1822 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
1823 | if (!temp_client) | |
1824 | return -ENOMEM; | |
1825 | temp_client->adapter = adapter; | |
1826 | ||
c3813d6a | 1827 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
4735c98f | 1828 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
c3813d6a JD |
1829 | "addr 0x%02x\n", adap_id, address_list[i]); |
1830 | temp_client->addr = address_list[i]; | |
ccfbbd08 | 1831 | err = i2c_detect_address(temp_client, driver); |
51b54ba9 JD |
1832 | if (unlikely(err)) |
1833 | break; | |
4735c98f JD |
1834 | } |
1835 | ||
4735c98f JD |
1836 | kfree(temp_client); |
1837 | return err; | |
1838 | } | |
1839 | ||
d44f19d5 JD |
1840 | int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) |
1841 | { | |
1842 | return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1843 | I2C_SMBUS_QUICK, NULL) >= 0; | |
1844 | } | |
1845 | EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); | |
1846 | ||
12b5053a JD |
1847 | struct i2c_client * |
1848 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1849 | struct i2c_board_info *info, | |
9a94241a JD |
1850 | unsigned short const *addr_list, |
1851 | int (*probe)(struct i2c_adapter *, unsigned short addr)) | |
12b5053a JD |
1852 | { |
1853 | int i; | |
1854 | ||
8031d79b | 1855 | if (!probe) |
9a94241a | 1856 | probe = i2c_default_probe; |
12b5053a | 1857 | |
12b5053a JD |
1858 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1859 | /* Check address validity */ | |
656b8761 | 1860 | if (i2c_check_addr_validity(addr_list[i]) < 0) { |
12b5053a JD |
1861 | dev_warn(&adap->dev, "Invalid 7-bit address " |
1862 | "0x%02x\n", addr_list[i]); | |
1863 | continue; | |
1864 | } | |
1865 | ||
1866 | /* Check address availability */ | |
3b5f794b | 1867 | if (i2c_check_addr_busy(adap, addr_list[i])) { |
12b5053a JD |
1868 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1869 | "use, not probing\n", addr_list[i]); | |
1870 | continue; | |
1871 | } | |
1872 | ||
63e4e802 | 1873 | /* Test address responsiveness */ |
9a94241a | 1874 | if (probe(adap, addr_list[i])) |
63e4e802 | 1875 | break; |
12b5053a | 1876 | } |
12b5053a JD |
1877 | |
1878 | if (addr_list[i] == I2C_CLIENT_END) { | |
1879 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1880 | return NULL; | |
1881 | } | |
1882 | ||
1883 | info->addr = addr_list[i]; | |
1884 | return i2c_new_device(adap, info); | |
1885 | } | |
1886 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
1887 | ||
d735b34d | 1888 | struct i2c_adapter *i2c_get_adapter(int nr) |
1da177e4 | 1889 | { |
1da177e4 | 1890 | struct i2c_adapter *adapter; |
438d6c2c | 1891 | |
caada32a | 1892 | mutex_lock(&core_lock); |
d735b34d | 1893 | adapter = idr_find(&i2c_adapter_idr, nr); |
a0920e10 MH |
1894 | if (adapter && !try_module_get(adapter->owner)) |
1895 | adapter = NULL; | |
1896 | ||
caada32a | 1897 | mutex_unlock(&core_lock); |
a0920e10 | 1898 | return adapter; |
1da177e4 | 1899 | } |
c0564606 | 1900 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
1901 | |
1902 | void i2c_put_adapter(struct i2c_adapter *adap) | |
1903 | { | |
1904 | module_put(adap->owner); | |
1905 | } | |
c0564606 | 1906 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
1907 | |
1908 | /* The SMBus parts */ | |
1909 | ||
438d6c2c | 1910 | #define POLY (0x1070U << 3) |
09b8ce0a | 1911 | static u8 crc8(u16 data) |
1da177e4 LT |
1912 | { |
1913 | int i; | |
438d6c2c | 1914 | |
7225acf4 | 1915 | for (i = 0; i < 8; i++) { |
438d6c2c | 1916 | if (data & 0x8000) |
1da177e4 LT |
1917 | data = data ^ POLY; |
1918 | data = data << 1; | |
1919 | } | |
1920 | return (u8)(data >> 8); | |
1921 | } | |
1922 | ||
421ef47b JD |
1923 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
1924 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
1925 | { |
1926 | int i; | |
1927 | ||
7225acf4 | 1928 | for (i = 0; i < count; i++) |
421ef47b | 1929 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
1930 | return crc; |
1931 | } | |
1932 | ||
421ef47b JD |
1933 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
1934 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 1935 | { |
421ef47b JD |
1936 | /* The address will be sent first */ |
1937 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
1938 | pec = i2c_smbus_pec(pec, &addr, 1); | |
1939 | ||
1940 | /* The data buffer follows */ | |
1941 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
1942 | } |
1943 | ||
421ef47b JD |
1944 | /* Used for write only transactions */ |
1945 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 1946 | { |
421ef47b JD |
1947 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
1948 | msg->len++; | |
1da177e4 LT |
1949 | } |
1950 | ||
421ef47b JD |
1951 | /* Return <0 on CRC error |
1952 | If there was a write before this read (most cases) we need to take the | |
1953 | partial CRC from the write part into account. | |
1954 | Note that this function does modify the message (we need to decrease the | |
1955 | message length to hide the CRC byte from the caller). */ | |
1956 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 1957 | { |
421ef47b JD |
1958 | u8 rpec = msg->buf[--msg->len]; |
1959 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 1960 | |
1da177e4 LT |
1961 | if (rpec != cpec) { |
1962 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
1963 | rpec, cpec); | |
24a5bb7b | 1964 | return -EBADMSG; |
1da177e4 | 1965 | } |
438d6c2c | 1966 | return 0; |
1da177e4 LT |
1967 | } |
1968 | ||
a1cdedac DB |
1969 | /** |
1970 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
1971 | * @client: Handle to slave device | |
1972 | * | |
1973 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
1974 | * else the byte received from the device. | |
1975 | */ | |
0cc43a18 | 1976 | s32 i2c_smbus_read_byte(const struct i2c_client *client) |
1da177e4 LT |
1977 | { |
1978 | union i2c_smbus_data data; | |
24a5bb7b DB |
1979 | int status; |
1980 | ||
1981 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1982 | I2C_SMBUS_READ, 0, | |
1983 | I2C_SMBUS_BYTE, &data); | |
1984 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1985 | } |
c0564606 | 1986 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 1987 | |
a1cdedac DB |
1988 | /** |
1989 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
1990 | * @client: Handle to slave device | |
1991 | * @value: Byte to be sent | |
1992 | * | |
1993 | * This executes the SMBus "send byte" protocol, returning negative errno | |
1994 | * else zero on success. | |
1995 | */ | |
0cc43a18 | 1996 | s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value) |
1da177e4 | 1997 | { |
7225acf4 | 1998 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
421ef47b | 1999 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 2000 | } |
c0564606 | 2001 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 2002 | |
a1cdedac DB |
2003 | /** |
2004 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
2005 | * @client: Handle to slave device | |
2006 | * @command: Byte interpreted by slave | |
2007 | * | |
2008 | * This executes the SMBus "read byte" protocol, returning negative errno | |
2009 | * else a data byte received from the device. | |
2010 | */ | |
0cc43a18 | 2011 | s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command) |
1da177e4 LT |
2012 | { |
2013 | union i2c_smbus_data data; | |
24a5bb7b DB |
2014 | int status; |
2015 | ||
2016 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2017 | I2C_SMBUS_READ, command, | |
2018 | I2C_SMBUS_BYTE_DATA, &data); | |
2019 | return (status < 0) ? status : data.byte; | |
1da177e4 | 2020 | } |
c0564606 | 2021 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 2022 | |
a1cdedac DB |
2023 | /** |
2024 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
2025 | * @client: Handle to slave device | |
2026 | * @command: Byte interpreted by slave | |
2027 | * @value: Byte being written | |
2028 | * | |
2029 | * This executes the SMBus "write byte" protocol, returning negative errno | |
2030 | * else zero on success. | |
2031 | */ | |
0cc43a18 JD |
2032 | s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command, |
2033 | u8 value) | |
1da177e4 LT |
2034 | { |
2035 | union i2c_smbus_data data; | |
2036 | data.byte = value; | |
7225acf4 FH |
2037 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2038 | I2C_SMBUS_WRITE, command, | |
2039 | I2C_SMBUS_BYTE_DATA, &data); | |
1da177e4 | 2040 | } |
c0564606 | 2041 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 2042 | |
a1cdedac DB |
2043 | /** |
2044 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
2045 | * @client: Handle to slave device | |
2046 | * @command: Byte interpreted by slave | |
2047 | * | |
2048 | * This executes the SMBus "read word" protocol, returning negative errno | |
2049 | * else a 16-bit unsigned "word" received from the device. | |
2050 | */ | |
0cc43a18 | 2051 | s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command) |
1da177e4 LT |
2052 | { |
2053 | union i2c_smbus_data data; | |
24a5bb7b DB |
2054 | int status; |
2055 | ||
2056 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2057 | I2C_SMBUS_READ, command, | |
2058 | I2C_SMBUS_WORD_DATA, &data); | |
2059 | return (status < 0) ? status : data.word; | |
1da177e4 | 2060 | } |
c0564606 | 2061 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 2062 | |
a1cdedac DB |
2063 | /** |
2064 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
2065 | * @client: Handle to slave device | |
2066 | * @command: Byte interpreted by slave | |
2067 | * @value: 16-bit "word" being written | |
2068 | * | |
2069 | * This executes the SMBus "write word" protocol, returning negative errno | |
2070 | * else zero on success. | |
2071 | */ | |
0cc43a18 JD |
2072 | s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command, |
2073 | u16 value) | |
1da177e4 LT |
2074 | { |
2075 | union i2c_smbus_data data; | |
2076 | data.word = value; | |
7225acf4 FH |
2077 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2078 | I2C_SMBUS_WRITE, command, | |
2079 | I2C_SMBUS_WORD_DATA, &data); | |
1da177e4 | 2080 | } |
c0564606 | 2081 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 2082 | |
a64ec07d | 2083 | /** |
a1cdedac | 2084 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 2085 | * @client: Handle to slave device |
a1cdedac | 2086 | * @command: Byte interpreted by slave |
a64ec07d DB |
2087 | * @values: Byte array into which data will be read; big enough to hold |
2088 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
2089 | * | |
a1cdedac DB |
2090 | * This executes the SMBus "block read" protocol, returning negative errno |
2091 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
2092 | * |
2093 | * Note that using this function requires that the client's adapter support | |
2094 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
2095 | * support this; its emulation through I2C messaging relies on a specific | |
2096 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
2097 | */ | |
0cc43a18 | 2098 | s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command, |
b86a1bc8 JD |
2099 | u8 *values) |
2100 | { | |
2101 | union i2c_smbus_data data; | |
24a5bb7b | 2102 | int status; |
b86a1bc8 | 2103 | |
24a5bb7b DB |
2104 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2105 | I2C_SMBUS_READ, command, | |
2106 | I2C_SMBUS_BLOCK_DATA, &data); | |
2107 | if (status) | |
2108 | return status; | |
b86a1bc8 JD |
2109 | |
2110 | memcpy(values, &data.block[1], data.block[0]); | |
2111 | return data.block[0]; | |
2112 | } | |
2113 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
2114 | ||
a1cdedac DB |
2115 | /** |
2116 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
2117 | * @client: Handle to slave device | |
2118 | * @command: Byte interpreted by slave | |
2119 | * @length: Size of data block; SMBus allows at most 32 bytes | |
2120 | * @values: Byte array which will be written. | |
2121 | * | |
2122 | * This executes the SMBus "block write" protocol, returning negative errno | |
2123 | * else zero on success. | |
2124 | */ | |
0cc43a18 | 2125 | s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command, |
46f5ed75 | 2126 | u8 length, const u8 *values) |
1da177e4 LT |
2127 | { |
2128 | union i2c_smbus_data data; | |
7656032b | 2129 | |
1da177e4 LT |
2130 | if (length > I2C_SMBUS_BLOCK_MAX) |
2131 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 2132 | data.block[0] = length; |
7656032b | 2133 | memcpy(&data.block[1], values, length); |
7225acf4 FH |
2134 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2135 | I2C_SMBUS_WRITE, command, | |
2136 | I2C_SMBUS_BLOCK_DATA, &data); | |
1da177e4 | 2137 | } |
c0564606 | 2138 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
2139 | |
2140 | /* Returns the number of read bytes */ | |
0cc43a18 | 2141 | s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command, |
4b2643d7 | 2142 | u8 length, u8 *values) |
1da177e4 LT |
2143 | { |
2144 | union i2c_smbus_data data; | |
24a5bb7b | 2145 | int status; |
7656032b | 2146 | |
4b2643d7 JD |
2147 | if (length > I2C_SMBUS_BLOCK_MAX) |
2148 | length = I2C_SMBUS_BLOCK_MAX; | |
2149 | data.block[0] = length; | |
24a5bb7b DB |
2150 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2151 | I2C_SMBUS_READ, command, | |
2152 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
2153 | if (status < 0) | |
2154 | return status; | |
7656032b JD |
2155 | |
2156 | memcpy(values, &data.block[1], data.block[0]); | |
2157 | return data.block[0]; | |
1da177e4 | 2158 | } |
c0564606 | 2159 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 2160 | |
0cc43a18 | 2161 | s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command, |
46f5ed75 | 2162 | u8 length, const u8 *values) |
21bbd691 JD |
2163 | { |
2164 | union i2c_smbus_data data; | |
2165 | ||
2166 | if (length > I2C_SMBUS_BLOCK_MAX) | |
2167 | length = I2C_SMBUS_BLOCK_MAX; | |
2168 | data.block[0] = length; | |
2169 | memcpy(data.block + 1, values, length); | |
2170 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2171 | I2C_SMBUS_WRITE, command, | |
2172 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
2173 | } | |
c0564606 | 2174 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 2175 | |
438d6c2c | 2176 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 2177 | No checking of parameters is done! */ |
7225acf4 FH |
2178 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, |
2179 | unsigned short flags, | |
2180 | char read_write, u8 command, int size, | |
2181 | union i2c_smbus_data *data) | |
1da177e4 LT |
2182 | { |
2183 | /* So we need to generate a series of msgs. In the case of writing, we | |
2184 | need to use only one message; when reading, we need two. We initialize | |
2185 | most things with sane defaults, to keep the code below somewhat | |
2186 | simpler. */ | |
5c50d188 HI |
2187 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
2188 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
7225acf4 | 2189 | int num = read_write == I2C_SMBUS_READ ? 2 : 1; |
1da177e4 | 2190 | int i; |
421ef47b | 2191 | u8 partial_pec = 0; |
24a5bb7b | 2192 | int status; |
230da094 S |
2193 | struct i2c_msg msg[2] = { |
2194 | { | |
2195 | .addr = addr, | |
2196 | .flags = flags, | |
2197 | .len = 1, | |
2198 | .buf = msgbuf0, | |
2199 | }, { | |
2200 | .addr = addr, | |
2201 | .flags = flags | I2C_M_RD, | |
2202 | .len = 0, | |
2203 | .buf = msgbuf1, | |
2204 | }, | |
2205 | }; | |
1da177e4 LT |
2206 | |
2207 | msgbuf0[0] = command; | |
7225acf4 | 2208 | switch (size) { |
1da177e4 LT |
2209 | case I2C_SMBUS_QUICK: |
2210 | msg[0].len = 0; | |
2211 | /* Special case: The read/write field is used as data */ | |
f29d2e02 RK |
2212 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
2213 | I2C_M_RD : 0); | |
1da177e4 LT |
2214 | num = 1; |
2215 | break; | |
2216 | case I2C_SMBUS_BYTE: | |
2217 | if (read_write == I2C_SMBUS_READ) { | |
2218 | /* Special case: only a read! */ | |
2219 | msg[0].flags = I2C_M_RD | flags; | |
2220 | num = 1; | |
2221 | } | |
2222 | break; | |
2223 | case I2C_SMBUS_BYTE_DATA: | |
2224 | if (read_write == I2C_SMBUS_READ) | |
2225 | msg[1].len = 1; | |
2226 | else { | |
2227 | msg[0].len = 2; | |
2228 | msgbuf0[1] = data->byte; | |
2229 | } | |
2230 | break; | |
2231 | case I2C_SMBUS_WORD_DATA: | |
2232 | if (read_write == I2C_SMBUS_READ) | |
2233 | msg[1].len = 2; | |
2234 | else { | |
7225acf4 | 2235 | msg[0].len = 3; |
1da177e4 | 2236 | msgbuf0[1] = data->word & 0xff; |
7eff82c8 | 2237 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
2238 | } |
2239 | break; | |
2240 | case I2C_SMBUS_PROC_CALL: | |
2241 | num = 2; /* Special case */ | |
2242 | read_write = I2C_SMBUS_READ; | |
2243 | msg[0].len = 3; | |
2244 | msg[1].len = 2; | |
2245 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 2246 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
2247 | break; |
2248 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 2249 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
2250 | msg[1].flags |= I2C_M_RECV_LEN; |
2251 | msg[1].len = 1; /* block length will be added by | |
2252 | the underlying bus driver */ | |
1da177e4 LT |
2253 | } else { |
2254 | msg[0].len = data->block[0] + 2; | |
2255 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
2256 | dev_err(&adapter->dev, |
2257 | "Invalid block write size %d\n", | |
2258 | data->block[0]); | |
2259 | return -EINVAL; | |
1da177e4 | 2260 | } |
5c50d188 | 2261 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
2262 | msgbuf0[i] = data->block[i-1]; |
2263 | } | |
2264 | break; | |
2265 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
2266 | num = 2; /* Another special case */ |
2267 | read_write = I2C_SMBUS_READ; | |
2268 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
2269 | dev_err(&adapter->dev, |
2270 | "Invalid block write size %d\n", | |
209d27c3 | 2271 | data->block[0]); |
24a5bb7b | 2272 | return -EINVAL; |
209d27c3 JD |
2273 | } |
2274 | msg[0].len = data->block[0] + 2; | |
2275 | for (i = 1; i < msg[0].len; i++) | |
2276 | msgbuf0[i] = data->block[i-1]; | |
2277 | msg[1].flags |= I2C_M_RECV_LEN; | |
2278 | msg[1].len = 1; /* block length will be added by | |
2279 | the underlying bus driver */ | |
2280 | break; | |
1da177e4 LT |
2281 | case I2C_SMBUS_I2C_BLOCK_DATA: |
2282 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 2283 | msg[1].len = data->block[0]; |
1da177e4 LT |
2284 | } else { |
2285 | msg[0].len = data->block[0] + 1; | |
30dac746 | 2286 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
2287 | dev_err(&adapter->dev, |
2288 | "Invalid block write size %d\n", | |
2289 | data->block[0]); | |
2290 | return -EINVAL; | |
1da177e4 LT |
2291 | } |
2292 | for (i = 1; i <= data->block[0]; i++) | |
2293 | msgbuf0[i] = data->block[i]; | |
2294 | } | |
2295 | break; | |
2296 | default: | |
24a5bb7b DB |
2297 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
2298 | return -EOPNOTSUPP; | |
1da177e4 LT |
2299 | } |
2300 | ||
421ef47b JD |
2301 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
2302 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
2303 | if (i) { | |
2304 | /* Compute PEC if first message is a write */ | |
2305 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 2306 | if (num == 1) /* Write only */ |
421ef47b JD |
2307 | i2c_smbus_add_pec(&msg[0]); |
2308 | else /* Write followed by read */ | |
2309 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
2310 | } | |
2311 | /* Ask for PEC if last message is a read */ | |
2312 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 2313 | msg[num-1].len++; |
421ef47b JD |
2314 | } |
2315 | ||
24a5bb7b DB |
2316 | status = i2c_transfer(adapter, msg, num); |
2317 | if (status < 0) | |
2318 | return status; | |
1da177e4 | 2319 | |
421ef47b JD |
2320 | /* Check PEC if last message is a read */ |
2321 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
2322 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
2323 | if (status < 0) | |
2324 | return status; | |
421ef47b JD |
2325 | } |
2326 | ||
1da177e4 | 2327 | if (read_write == I2C_SMBUS_READ) |
7225acf4 FH |
2328 | switch (size) { |
2329 | case I2C_SMBUS_BYTE: | |
2330 | data->byte = msgbuf0[0]; | |
2331 | break; | |
2332 | case I2C_SMBUS_BYTE_DATA: | |
2333 | data->byte = msgbuf1[0]; | |
2334 | break; | |
2335 | case I2C_SMBUS_WORD_DATA: | |
2336 | case I2C_SMBUS_PROC_CALL: | |
2337 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
2338 | break; | |
2339 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
2340 | for (i = 0; i < data->block[0]; i++) | |
2341 | data->block[i+1] = msgbuf1[i]; | |
2342 | break; | |
2343 | case I2C_SMBUS_BLOCK_DATA: | |
2344 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
2345 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
2346 | data->block[i] = msgbuf1[i]; | |
2347 | break; | |
1da177e4 LT |
2348 | } |
2349 | return 0; | |
2350 | } | |
2351 | ||
a1cdedac DB |
2352 | /** |
2353 | * i2c_smbus_xfer - execute SMBus protocol operations | |
2354 | * @adapter: Handle to I2C bus | |
2355 | * @addr: Address of SMBus slave on that bus | |
2356 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
2357 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
2358 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
2359 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
2360 | * @data: Data to be read or written | |
2361 | * | |
2362 | * This executes an SMBus protocol operation, and returns a negative | |
2363 | * errno code else zero on success. | |
2364 | */ | |
09b8ce0a | 2365 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
a1cdedac | 2366 | char read_write, u8 command, int protocol, |
09b8ce0a | 2367 | union i2c_smbus_data *data) |
1da177e4 | 2368 | { |
66b650f0 CW |
2369 | unsigned long orig_jiffies; |
2370 | int try; | |
1da177e4 | 2371 | s32 res; |
1da177e4 | 2372 | |
d47726c5 | 2373 | flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB; |
1da177e4 LT |
2374 | |
2375 | if (adapter->algo->smbus_xfer) { | |
fe61e07e | 2376 | i2c_lock_adapter(adapter); |
66b650f0 CW |
2377 | |
2378 | /* Retry automatically on arbitration loss */ | |
2379 | orig_jiffies = jiffies; | |
2380 | for (res = 0, try = 0; try <= adapter->retries; try++) { | |
2381 | res = adapter->algo->smbus_xfer(adapter, addr, flags, | |
2382 | read_write, command, | |
2383 | protocol, data); | |
2384 | if (res != -EAGAIN) | |
2385 | break; | |
2386 | if (time_after(jiffies, | |
2387 | orig_jiffies + adapter->timeout)) | |
2388 | break; | |
2389 | } | |
fe61e07e | 2390 | i2c_unlock_adapter(adapter); |
1da177e4 | 2391 | |
72fc2c7f LP |
2392 | if (res != -EOPNOTSUPP || !adapter->algo->master_xfer) |
2393 | return res; | |
2394 | /* | |
2395 | * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't | |
2396 | * implement native support for the SMBus operation. | |
2397 | */ | |
2398 | } | |
2399 | ||
2400 | return i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, | |
2401 | command, protocol, data); | |
1da177e4 | 2402 | } |
1da177e4 | 2403 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
2404 | |
2405 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
2406 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
2407 | MODULE_LICENSE("GPL"); |