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 |
7c81c60f | 24 | Jean Delvare <jdelvare@suse.de> |
0826374b | 25 | Mux support by Rodolfo Giometti <giometti@enneenne.com> and |
687b81d0 WS |
26 | Michael Lawnick <michael.lawnick.ext@nsn.com> |
27 | OF support is copyright (c) 2008 Jochen Friedrich <jochen@scram.de> | |
28 | (based on a previous patch from Jon Smirl <jonsmirl@gmail.com>) and | |
29 | (c) 2013 Wolfram Sang <wsa@the-dreams.de> | |
30 | */ | |
1da177e4 | 31 | |
1da177e4 LT |
32 | #include <linux/module.h> |
33 | #include <linux/kernel.h> | |
5f9296ba | 34 | #include <linux/delay.h> |
1da177e4 | 35 | #include <linux/errno.h> |
5f9296ba | 36 | #include <linux/gpio.h> |
1da177e4 LT |
37 | #include <linux/slab.h> |
38 | #include <linux/i2c.h> | |
39 | #include <linux/init.h> | |
40 | #include <linux/idr.h> | |
b3585e4f | 41 | #include <linux/mutex.h> |
687b81d0 | 42 | #include <linux/of.h> |
959e85f7 | 43 | #include <linux/of_device.h> |
687b81d0 | 44 | #include <linux/of_irq.h> |
86be408b | 45 | #include <linux/clk/clk-conf.h> |
b8d6f45b | 46 | #include <linux/completion.h> |
cea443a8 MR |
47 | #include <linux/hardirq.h> |
48 | #include <linux/irqflags.h> | |
f18c41da | 49 | #include <linux/rwsem.h> |
6de468ae | 50 | #include <linux/pm_runtime.h> |
907ddf89 | 51 | #include <linux/acpi.h> |
d9a83d62 | 52 | #include <linux/jump_label.h> |
1da177e4 LT |
53 | #include <asm/uaccess.h> |
54 | ||
9c1600ed DB |
55 | #include "i2c-core.h" |
56 | ||
d9a83d62 DH |
57 | #define CREATE_TRACE_POINTS |
58 | #include <trace/events/i2c.h> | |
1da177e4 | 59 | |
6629dcff | 60 | /* core_lock protects i2c_adapter_idr, and guarantees |
35fc37f8 | 61 | that device detection, deletion of detected devices, and attach_adapter |
19baba4c | 62 | calls are serialized */ |
caada32a | 63 | static DEFINE_MUTEX(core_lock); |
1da177e4 LT |
64 | static DEFINE_IDR(i2c_adapter_idr); |
65 | ||
4f8cf824 | 66 | static struct device_type i2c_client_type; |
4735c98f | 67 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
f37dd80a | 68 | |
d9a83d62 DH |
69 | static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE; |
70 | ||
71 | void i2c_transfer_trace_reg(void) | |
72 | { | |
73 | static_key_slow_inc(&i2c_trace_msg); | |
74 | } | |
75 | ||
76 | void i2c_transfer_trace_unreg(void) | |
77 | { | |
78 | static_key_slow_dec(&i2c_trace_msg); | |
79 | } | |
80 | ||
f37dd80a DB |
81 | /* ------------------------------------------------------------------------- */ |
82 | ||
d2653e92 JD |
83 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
84 | const struct i2c_client *client) | |
85 | { | |
86 | while (id->name[0]) { | |
87 | if (strcmp(client->name, id->name) == 0) | |
88 | return id; | |
89 | id++; | |
90 | } | |
91 | return NULL; | |
92 | } | |
93 | ||
1da177e4 LT |
94 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
95 | { | |
51298d12 JD |
96 | struct i2c_client *client = i2c_verify_client(dev); |
97 | struct i2c_driver *driver; | |
98 | ||
99 | if (!client) | |
100 | return 0; | |
7b4fbc50 | 101 | |
959e85f7 GL |
102 | /* Attempt an OF style match */ |
103 | if (of_driver_match_device(dev, drv)) | |
104 | return 1; | |
105 | ||
907ddf89 MW |
106 | /* Then ACPI style match */ |
107 | if (acpi_driver_match_device(dev, drv)) | |
108 | return 1; | |
109 | ||
51298d12 | 110 | driver = to_i2c_driver(drv); |
d2653e92 JD |
111 | /* match on an id table if there is one */ |
112 | if (driver->id_table) | |
113 | return i2c_match_id(driver->id_table, client) != NULL; | |
114 | ||
eb8a7908 | 115 | return 0; |
1da177e4 LT |
116 | } |
117 | ||
7b4fbc50 DB |
118 | |
119 | /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ | |
7eff2e7a | 120 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 DB |
121 | { |
122 | struct i2c_client *client = to_i2c_client(dev); | |
8c4ff6d0 ZR |
123 | int rc; |
124 | ||
125 | rc = acpi_device_uevent_modalias(dev, env); | |
126 | if (rc != -ENODEV) | |
127 | return rc; | |
7b4fbc50 | 128 | |
eb8a7908 JD |
129 | if (add_uevent_var(env, "MODALIAS=%s%s", |
130 | I2C_MODULE_PREFIX, client->name)) | |
131 | return -ENOMEM; | |
7b4fbc50 DB |
132 | dev_dbg(dev, "uevent\n"); |
133 | return 0; | |
134 | } | |
135 | ||
5f9296ba VK |
136 | /* i2c bus recovery routines */ |
137 | static int get_scl_gpio_value(struct i2c_adapter *adap) | |
138 | { | |
139 | return gpio_get_value(adap->bus_recovery_info->scl_gpio); | |
140 | } | |
141 | ||
142 | static void set_scl_gpio_value(struct i2c_adapter *adap, int val) | |
143 | { | |
144 | gpio_set_value(adap->bus_recovery_info->scl_gpio, val); | |
145 | } | |
146 | ||
147 | static int get_sda_gpio_value(struct i2c_adapter *adap) | |
148 | { | |
149 | return gpio_get_value(adap->bus_recovery_info->sda_gpio); | |
150 | } | |
151 | ||
152 | static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap) | |
153 | { | |
154 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
155 | struct device *dev = &adap->dev; | |
156 | int ret = 0; | |
157 | ||
158 | ret = gpio_request_one(bri->scl_gpio, GPIOF_OPEN_DRAIN | | |
159 | GPIOF_OUT_INIT_HIGH, "i2c-scl"); | |
160 | if (ret) { | |
161 | dev_warn(dev, "Can't get SCL gpio: %d\n", bri->scl_gpio); | |
162 | return ret; | |
163 | } | |
164 | ||
165 | if (bri->get_sda) { | |
166 | if (gpio_request_one(bri->sda_gpio, GPIOF_IN, "i2c-sda")) { | |
167 | /* work without SDA polling */ | |
168 | dev_warn(dev, "Can't get SDA gpio: %d. Not using SDA polling\n", | |
169 | bri->sda_gpio); | |
170 | bri->get_sda = NULL; | |
171 | } | |
172 | } | |
173 | ||
174 | return ret; | |
175 | } | |
176 | ||
177 | static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap) | |
178 | { | |
179 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
180 | ||
181 | if (bri->get_sda) | |
182 | gpio_free(bri->sda_gpio); | |
183 | ||
184 | gpio_free(bri->scl_gpio); | |
185 | } | |
186 | ||
187 | /* | |
188 | * We are generating clock pulses. ndelay() determines durating of clk pulses. | |
189 | * We will generate clock with rate 100 KHz and so duration of both clock levels | |
190 | * is: delay in ns = (10^6 / 100) / 2 | |
191 | */ | |
192 | #define RECOVERY_NDELAY 5000 | |
193 | #define RECOVERY_CLK_CNT 9 | |
194 | ||
195 | static int i2c_generic_recovery(struct i2c_adapter *adap) | |
196 | { | |
197 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
198 | int i = 0, val = 1, ret = 0; | |
199 | ||
200 | if (bri->prepare_recovery) | |
201 | bri->prepare_recovery(bri); | |
202 | ||
203 | /* | |
204 | * By this time SCL is high, as we need to give 9 falling-rising edges | |
205 | */ | |
206 | while (i++ < RECOVERY_CLK_CNT * 2) { | |
207 | if (val) { | |
208 | /* Break if SDA is high */ | |
209 | if (bri->get_sda && bri->get_sda(adap)) | |
210 | break; | |
211 | /* SCL shouldn't be low here */ | |
212 | if (!bri->get_scl(adap)) { | |
213 | dev_err(&adap->dev, | |
214 | "SCL is stuck low, exit recovery\n"); | |
215 | ret = -EBUSY; | |
216 | break; | |
217 | } | |
218 | } | |
219 | ||
220 | val = !val; | |
221 | bri->set_scl(adap, val); | |
222 | ndelay(RECOVERY_NDELAY); | |
223 | } | |
224 | ||
225 | if (bri->unprepare_recovery) | |
226 | bri->unprepare_recovery(bri); | |
227 | ||
228 | return ret; | |
229 | } | |
230 | ||
231 | int i2c_generic_scl_recovery(struct i2c_adapter *adap) | |
232 | { | |
233 | adap->bus_recovery_info->set_scl(adap, 1); | |
234 | return i2c_generic_recovery(adap); | |
235 | } | |
236 | ||
237 | int i2c_generic_gpio_recovery(struct i2c_adapter *adap) | |
238 | { | |
239 | int ret; | |
240 | ||
241 | ret = i2c_get_gpios_for_recovery(adap); | |
242 | if (ret) | |
243 | return ret; | |
244 | ||
245 | ret = i2c_generic_recovery(adap); | |
246 | i2c_put_gpios_for_recovery(adap); | |
247 | ||
248 | return ret; | |
249 | } | |
250 | ||
251 | int i2c_recover_bus(struct i2c_adapter *adap) | |
252 | { | |
253 | if (!adap->bus_recovery_info) | |
254 | return -EOPNOTSUPP; | |
255 | ||
256 | dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); | |
257 | return adap->bus_recovery_info->recover_bus(adap); | |
258 | } | |
259 | ||
f37dd80a | 260 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 261 | { |
51298d12 JD |
262 | struct i2c_client *client = i2c_verify_client(dev); |
263 | struct i2c_driver *driver; | |
50c3304a | 264 | int status; |
7b4fbc50 | 265 | |
51298d12 JD |
266 | if (!client) |
267 | return 0; | |
268 | ||
269 | driver = to_i2c_driver(dev->driver); | |
e0457442 | 270 | if (!driver->probe || !driver->id_table) |
7b4fbc50 | 271 | return -ENODEV; |
0acc2b32 | 272 | |
ee35425c MP |
273 | if (!device_can_wakeup(&client->dev)) |
274 | device_init_wakeup(&client->dev, | |
275 | client->flags & I2C_CLIENT_WAKE); | |
7b4fbc50 | 276 | dev_dbg(dev, "probe\n"); |
d2653e92 | 277 | |
86be408b SN |
278 | status = of_clk_set_defaults(dev->of_node, false); |
279 | if (status < 0) | |
280 | return status; | |
281 | ||
a76e9bd8 | 282 | acpi_dev_pm_attach(&client->dev, true); |
e0457442 | 283 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
72fa818e | 284 | if (status) |
a76e9bd8 | 285 | acpi_dev_pm_detach(&client->dev, true); |
72fa818e | 286 | |
50c3304a | 287 | return status; |
f37dd80a | 288 | } |
1da177e4 | 289 | |
f37dd80a DB |
290 | static int i2c_device_remove(struct device *dev) |
291 | { | |
51298d12 | 292 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 | 293 | struct i2c_driver *driver; |
72fa818e | 294 | int status = 0; |
a1d9e6e4 | 295 | |
51298d12 | 296 | if (!client || !dev->driver) |
a1d9e6e4 DB |
297 | return 0; |
298 | ||
299 | driver = to_i2c_driver(dev->driver); | |
300 | if (driver->remove) { | |
301 | dev_dbg(dev, "remove\n"); | |
302 | status = driver->remove(client); | |
a1d9e6e4 | 303 | } |
72fa818e | 304 | |
a76e9bd8 | 305 | acpi_dev_pm_detach(&client->dev, true); |
a1d9e6e4 | 306 | return status; |
1da177e4 LT |
307 | } |
308 | ||
f37dd80a | 309 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 310 | { |
51298d12 | 311 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
312 | struct i2c_driver *driver; |
313 | ||
51298d12 | 314 | if (!client || !dev->driver) |
f37dd80a DB |
315 | return; |
316 | driver = to_i2c_driver(dev->driver); | |
317 | if (driver->shutdown) | |
51298d12 | 318 | driver->shutdown(client); |
1da177e4 LT |
319 | } |
320 | ||
2f60ba70 RW |
321 | #ifdef CONFIG_PM_SLEEP |
322 | static int i2c_legacy_suspend(struct device *dev, pm_message_t mesg) | |
54067ee2 | 323 | { |
2f60ba70 RW |
324 | struct i2c_client *client = i2c_verify_client(dev); |
325 | struct i2c_driver *driver; | |
54067ee2 | 326 | |
2f60ba70 | 327 | if (!client || !dev->driver) |
54067ee2 | 328 | return 0; |
2f60ba70 RW |
329 | driver = to_i2c_driver(dev->driver); |
330 | if (!driver->suspend) | |
54067ee2 | 331 | return 0; |
2f60ba70 | 332 | return driver->suspend(client, mesg); |
54067ee2 | 333 | } |
334 | ||
2f60ba70 | 335 | static int i2c_legacy_resume(struct device *dev) |
54067ee2 | 336 | { |
2f60ba70 RW |
337 | struct i2c_client *client = i2c_verify_client(dev); |
338 | struct i2c_driver *driver; | |
54067ee2 | 339 | |
2f60ba70 | 340 | if (!client || !dev->driver) |
54067ee2 | 341 | return 0; |
2f60ba70 RW |
342 | driver = to_i2c_driver(dev->driver); |
343 | if (!driver->resume) | |
54067ee2 | 344 | return 0; |
2f60ba70 | 345 | return driver->resume(client); |
54067ee2 | 346 | } |
54067ee2 | 347 | |
2f60ba70 | 348 | static int i2c_device_pm_suspend(struct device *dev) |
6de468ae | 349 | { |
2f60ba70 | 350 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 351 | |
d529de29 MB |
352 | if (pm) |
353 | return pm_generic_suspend(dev); | |
354 | else | |
355 | return i2c_legacy_suspend(dev, PMSG_SUSPEND); | |
6de468ae MB |
356 | } |
357 | ||
2f60ba70 | 358 | static int i2c_device_pm_resume(struct device *dev) |
6de468ae | 359 | { |
2f60ba70 | 360 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 361 | |
2f60ba70 | 362 | if (pm) |
d529de29 | 363 | return pm_generic_resume(dev); |
2f60ba70 | 364 | else |
d529de29 | 365 | return i2c_legacy_resume(dev); |
6de468ae | 366 | } |
6de468ae | 367 | |
2f60ba70 | 368 | static int i2c_device_pm_freeze(struct device *dev) |
1da177e4 | 369 | { |
2f60ba70 | 370 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 371 | |
d529de29 MB |
372 | if (pm) |
373 | return pm_generic_freeze(dev); | |
374 | else | |
375 | return i2c_legacy_suspend(dev, PMSG_FREEZE); | |
1da177e4 LT |
376 | } |
377 | ||
2f60ba70 | 378 | static int i2c_device_pm_thaw(struct device *dev) |
1da177e4 | 379 | { |
2f60ba70 | 380 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 381 | |
d529de29 MB |
382 | if (pm) |
383 | return pm_generic_thaw(dev); | |
384 | else | |
385 | return i2c_legacy_resume(dev); | |
2f60ba70 RW |
386 | } |
387 | ||
388 | static int i2c_device_pm_poweroff(struct device *dev) | |
389 | { | |
390 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
391 | ||
d529de29 MB |
392 | if (pm) |
393 | return pm_generic_poweroff(dev); | |
394 | else | |
395 | return i2c_legacy_suspend(dev, PMSG_HIBERNATE); | |
2f60ba70 RW |
396 | } |
397 | ||
398 | static int i2c_device_pm_restore(struct device *dev) | |
399 | { | |
400 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
2f60ba70 RW |
401 | |
402 | if (pm) | |
d529de29 | 403 | return pm_generic_restore(dev); |
2f60ba70 | 404 | else |
d529de29 | 405 | return i2c_legacy_resume(dev); |
1da177e4 | 406 | } |
2f60ba70 RW |
407 | #else /* !CONFIG_PM_SLEEP */ |
408 | #define i2c_device_pm_suspend NULL | |
409 | #define i2c_device_pm_resume NULL | |
410 | #define i2c_device_pm_freeze NULL | |
411 | #define i2c_device_pm_thaw NULL | |
412 | #define i2c_device_pm_poweroff NULL | |
413 | #define i2c_device_pm_restore NULL | |
414 | #endif /* !CONFIG_PM_SLEEP */ | |
1da177e4 | 415 | |
9c1600ed DB |
416 | static void i2c_client_dev_release(struct device *dev) |
417 | { | |
418 | kfree(to_i2c_client(dev)); | |
419 | } | |
420 | ||
09b8ce0a | 421 | static ssize_t |
4f8cf824 | 422 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 423 | { |
4f8cf824 JD |
424 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
425 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 DB |
426 | } |
427 | ||
09b8ce0a ZX |
428 | static ssize_t |
429 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
430 | { |
431 | struct i2c_client *client = to_i2c_client(dev); | |
8c4ff6d0 ZR |
432 | int len; |
433 | ||
434 | len = acpi_device_modalias(dev, buf, PAGE_SIZE -1); | |
435 | if (len != -ENODEV) | |
436 | return len; | |
437 | ||
eb8a7908 | 438 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
439 | } |
440 | ||
4f8cf824 | 441 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
51298d12 JD |
442 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
443 | ||
444 | static struct attribute *i2c_dev_attrs[] = { | |
445 | &dev_attr_name.attr, | |
7b4fbc50 | 446 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
447 | &dev_attr_modalias.attr, |
448 | NULL | |
449 | }; | |
450 | ||
451 | static struct attribute_group i2c_dev_attr_group = { | |
452 | .attrs = i2c_dev_attrs, | |
453 | }; | |
454 | ||
455 | static const struct attribute_group *i2c_dev_attr_groups[] = { | |
456 | &i2c_dev_attr_group, | |
457 | NULL | |
7b4fbc50 DB |
458 | }; |
459 | ||
0b2c3688 | 460 | static const struct dev_pm_ops i2c_device_pm_ops = { |
54067ee2 | 461 | .suspend = i2c_device_pm_suspend, |
462 | .resume = i2c_device_pm_resume, | |
2f60ba70 RW |
463 | .freeze = i2c_device_pm_freeze, |
464 | .thaw = i2c_device_pm_thaw, | |
465 | .poweroff = i2c_device_pm_poweroff, | |
466 | .restore = i2c_device_pm_restore, | |
467 | SET_RUNTIME_PM_OPS( | |
468 | pm_generic_runtime_suspend, | |
469 | pm_generic_runtime_resume, | |
45f0a85c | 470 | NULL |
2f60ba70 | 471 | ) |
54067ee2 | 472 | }; |
473 | ||
e9ca9eb9 | 474 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
475 | .name = "i2c", |
476 | .match = i2c_device_match, | |
477 | .probe = i2c_device_probe, | |
478 | .remove = i2c_device_remove, | |
479 | .shutdown = i2c_device_shutdown, | |
54067ee2 | 480 | .pm = &i2c_device_pm_ops, |
b864c7d5 | 481 | }; |
e9ca9eb9 | 482 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 483 | |
51298d12 JD |
484 | static struct device_type i2c_client_type = { |
485 | .groups = i2c_dev_attr_groups, | |
486 | .uevent = i2c_device_uevent, | |
487 | .release = i2c_client_dev_release, | |
488 | }; | |
489 | ||
9b766b81 DB |
490 | |
491 | /** | |
492 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
493 | * @dev: device, probably from some driver model iterator | |
494 | * | |
495 | * When traversing the driver model tree, perhaps using driver model | |
496 | * iterators like @device_for_each_child(), you can't assume very much | |
497 | * about the nodes you find. Use this function to avoid oopses caused | |
498 | * by wrongly treating some non-I2C device as an i2c_client. | |
499 | */ | |
500 | struct i2c_client *i2c_verify_client(struct device *dev) | |
501 | { | |
51298d12 | 502 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
503 | ? to_i2c_client(dev) |
504 | : NULL; | |
505 | } | |
506 | EXPORT_SYMBOL(i2c_verify_client); | |
507 | ||
508 | ||
3a89db5f | 509 | /* This is a permissive address validity check, I2C address map constraints |
25985edc | 510 | * are purposely not enforced, except for the general call address. */ |
3a89db5f JD |
511 | static int i2c_check_client_addr_validity(const struct i2c_client *client) |
512 | { | |
513 | if (client->flags & I2C_CLIENT_TEN) { | |
514 | /* 10-bit address, all values are valid */ | |
515 | if (client->addr > 0x3ff) | |
516 | return -EINVAL; | |
517 | } else { | |
518 | /* 7-bit address, reject the general call address */ | |
519 | if (client->addr == 0x00 || client->addr > 0x7f) | |
520 | return -EINVAL; | |
521 | } | |
522 | return 0; | |
523 | } | |
524 | ||
656b8761 JD |
525 | /* And this is a strict address validity check, used when probing. If a |
526 | * device uses a reserved address, then it shouldn't be probed. 7-bit | |
527 | * addressing is assumed, 10-bit address devices are rare and should be | |
528 | * explicitly enumerated. */ | |
529 | static int i2c_check_addr_validity(unsigned short addr) | |
530 | { | |
531 | /* | |
532 | * Reserved addresses per I2C specification: | |
533 | * 0x00 General call address / START byte | |
534 | * 0x01 CBUS address | |
535 | * 0x02 Reserved for different bus format | |
536 | * 0x03 Reserved for future purposes | |
537 | * 0x04-0x07 Hs-mode master code | |
538 | * 0x78-0x7b 10-bit slave addressing | |
539 | * 0x7c-0x7f Reserved for future purposes | |
540 | */ | |
541 | if (addr < 0x08 || addr > 0x77) | |
542 | return -EINVAL; | |
543 | return 0; | |
544 | } | |
545 | ||
3b5f794b JD |
546 | static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
547 | { | |
548 | struct i2c_client *client = i2c_verify_client(dev); | |
549 | int addr = *(int *)addrp; | |
550 | ||
551 | if (client && client->addr == addr) | |
552 | return -EBUSY; | |
553 | return 0; | |
554 | } | |
555 | ||
0826374b ML |
556 | /* walk up mux tree */ |
557 | static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
558 | { | |
97cc4d49 | 559 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
560 | int result; |
561 | ||
562 | result = device_for_each_child(&adapter->dev, &addr, | |
563 | __i2c_check_addr_busy); | |
564 | ||
97cc4d49 JD |
565 | if (!result && parent) |
566 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
567 | |
568 | return result; | |
569 | } | |
570 | ||
571 | /* recurse down mux tree */ | |
572 | static int i2c_check_mux_children(struct device *dev, void *addrp) | |
573 | { | |
574 | int result; | |
575 | ||
576 | if (dev->type == &i2c_adapter_type) | |
577 | result = device_for_each_child(dev, addrp, | |
578 | i2c_check_mux_children); | |
579 | else | |
580 | result = __i2c_check_addr_busy(dev, addrp); | |
581 | ||
582 | return result; | |
583 | } | |
584 | ||
3b5f794b JD |
585 | static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) |
586 | { | |
97cc4d49 | 587 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
588 | int result = 0; |
589 | ||
97cc4d49 JD |
590 | if (parent) |
591 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
592 | |
593 | if (!result) | |
594 | result = device_for_each_child(&adapter->dev, &addr, | |
595 | i2c_check_mux_children); | |
596 | ||
597 | return result; | |
3b5f794b JD |
598 | } |
599 | ||
fe61e07e JD |
600 | /** |
601 | * i2c_lock_adapter - Get exclusive access to an I2C bus segment | |
602 | * @adapter: Target I2C bus segment | |
603 | */ | |
604 | void i2c_lock_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_lock_adapter(parent); | |
0826374b ML |
610 | else |
611 | rt_mutex_lock(&adapter->bus_lock); | |
fe61e07e JD |
612 | } |
613 | EXPORT_SYMBOL_GPL(i2c_lock_adapter); | |
614 | ||
615 | /** | |
616 | * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment | |
617 | * @adapter: Target I2C bus segment | |
618 | */ | |
619 | static int i2c_trylock_adapter(struct i2c_adapter *adapter) | |
620 | { | |
97cc4d49 JD |
621 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
622 | ||
623 | if (parent) | |
624 | return i2c_trylock_adapter(parent); | |
0826374b ML |
625 | else |
626 | return rt_mutex_trylock(&adapter->bus_lock); | |
fe61e07e JD |
627 | } |
628 | ||
629 | /** | |
630 | * i2c_unlock_adapter - Release exclusive access to an I2C bus segment | |
631 | * @adapter: Target I2C bus segment | |
632 | */ | |
633 | void i2c_unlock_adapter(struct i2c_adapter *adapter) | |
634 | { | |
97cc4d49 JD |
635 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
636 | ||
637 | if (parent) | |
638 | i2c_unlock_adapter(parent); | |
0826374b ML |
639 | else |
640 | rt_mutex_unlock(&adapter->bus_lock); | |
fe61e07e JD |
641 | } |
642 | EXPORT_SYMBOL_GPL(i2c_unlock_adapter); | |
643 | ||
70762abb JN |
644 | static void i2c_dev_set_name(struct i2c_adapter *adap, |
645 | struct i2c_client *client) | |
646 | { | |
647 | struct acpi_device *adev = ACPI_COMPANION(&client->dev); | |
648 | ||
649 | if (adev) { | |
650 | dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); | |
651 | return; | |
652 | } | |
653 | ||
654 | /* For 10-bit clients, add an arbitrary offset to avoid collisions */ | |
655 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), | |
656 | client->addr | ((client->flags & I2C_CLIENT_TEN) | |
657 | ? 0xa000 : 0)); | |
658 | } | |
659 | ||
9c1600ed | 660 | /** |
f8a227e8 | 661 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
662 | * @adap: the adapter managing the device |
663 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 664 | * Context: can sleep |
9c1600ed | 665 | * |
f8a227e8 JD |
666 | * Create an i2c device. Binding is handled through driver model |
667 | * probe()/remove() methods. A driver may be bound to this device when we | |
668 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
669 | * load the driver module). This call is not appropriate for use by mainboard | |
670 | * initialization logic, which usually runs during an arch_initcall() long | |
671 | * before any i2c_adapter could exist. | |
9c1600ed DB |
672 | * |
673 | * This returns the new i2c client, which may be saved for later use with | |
674 | * i2c_unregister_device(); or NULL to indicate an error. | |
675 | */ | |
676 | struct i2c_client * | |
677 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
678 | { | |
679 | struct i2c_client *client; | |
680 | int status; | |
681 | ||
682 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
683 | if (!client) | |
684 | return NULL; | |
685 | ||
686 | client->adapter = adap; | |
687 | ||
688 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 689 | |
11f1f2af AV |
690 | if (info->archdata) |
691 | client->dev.archdata = *info->archdata; | |
692 | ||
ee35425c | 693 | client->flags = info->flags; |
9c1600ed DB |
694 | client->addr = info->addr; |
695 | client->irq = info->irq; | |
696 | ||
9c1600ed DB |
697 | strlcpy(client->name, info->type, sizeof(client->name)); |
698 | ||
3a89db5f JD |
699 | /* Check for address validity */ |
700 | status = i2c_check_client_addr_validity(client); | |
701 | if (status) { | |
702 | dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", | |
703 | client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); | |
704 | goto out_err_silent; | |
705 | } | |
706 | ||
f8a227e8 | 707 | /* Check for address business */ |
3b5f794b | 708 | status = i2c_check_addr_busy(adap, client->addr); |
f8a227e8 JD |
709 | if (status) |
710 | goto out_err; | |
711 | ||
712 | client->dev.parent = &client->adapter->dev; | |
713 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 714 | client->dev.type = &i2c_client_type; |
d12d42f7 | 715 | client->dev.of_node = info->of_node; |
7b199811 | 716 | ACPI_COMPANION_SET(&client->dev, info->acpi_node.companion); |
f8a227e8 | 717 | |
70762abb | 718 | i2c_dev_set_name(adap, client); |
f8a227e8 JD |
719 | status = device_register(&client->dev); |
720 | if (status) | |
721 | goto out_err; | |
722 | ||
f8a227e8 JD |
723 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
724 | client->name, dev_name(&client->dev)); | |
725 | ||
9c1600ed | 726 | return client; |
f8a227e8 JD |
727 | |
728 | out_err: | |
729 | dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " | |
730 | "(%d)\n", client->name, client->addr, status); | |
3a89db5f | 731 | out_err_silent: |
f8a227e8 JD |
732 | kfree(client); |
733 | return NULL; | |
9c1600ed DB |
734 | } |
735 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
736 | ||
737 | ||
738 | /** | |
739 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
740 | * @client: value returned from i2c_new_device() | |
d64f73be | 741 | * Context: can sleep |
9c1600ed DB |
742 | */ |
743 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 744 | { |
a1d9e6e4 DB |
745 | device_unregister(&client->dev); |
746 | } | |
9c1600ed | 747 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
748 | |
749 | ||
60b129d7 JD |
750 | static const struct i2c_device_id dummy_id[] = { |
751 | { "dummy", 0 }, | |
752 | { }, | |
753 | }; | |
754 | ||
d2653e92 JD |
755 | static int dummy_probe(struct i2c_client *client, |
756 | const struct i2c_device_id *id) | |
757 | { | |
758 | return 0; | |
759 | } | |
760 | ||
761 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
762 | { |
763 | return 0; | |
764 | } | |
765 | ||
766 | static struct i2c_driver dummy_driver = { | |
767 | .driver.name = "dummy", | |
d2653e92 JD |
768 | .probe = dummy_probe, |
769 | .remove = dummy_remove, | |
60b129d7 | 770 | .id_table = dummy_id, |
e9f1373b DB |
771 | }; |
772 | ||
773 | /** | |
774 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
775 | * @adapter: the adapter managing the device | |
776 | * @address: seven bit address to be used | |
e9f1373b DB |
777 | * Context: can sleep |
778 | * | |
779 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
780 | * with devices that consume multiple addresses. Examples of such chips | |
781 | * include various EEPROMS (like 24c04 and 24c08 models). | |
782 | * | |
783 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
784 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
785 | * And second, this prevents the specified address from being bound to a | |
786 | * different driver. | |
787 | * | |
788 | * This returns the new i2c client, which should be saved for later use with | |
789 | * i2c_unregister_device(); or NULL to indicate an error. | |
790 | */ | |
09b8ce0a | 791 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
792 | { |
793 | struct i2c_board_info info = { | |
60b129d7 | 794 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
795 | }; |
796 | ||
e9f1373b DB |
797 | return i2c_new_device(adapter, &info); |
798 | } | |
799 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
800 | ||
f37dd80a DB |
801 | /* ------------------------------------------------------------------------- */ |
802 | ||
16ffadfc DB |
803 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
804 | ||
83eaaed0 | 805 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 806 | { |
ef2c8321 | 807 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
808 | complete(&adap->dev_released); |
809 | } | |
810 | ||
390946b1 JD |
811 | /* |
812 | * This function is only needed for mutex_lock_nested, so it is never | |
813 | * called unless locking correctness checking is enabled. Thus we | |
814 | * make it inline to avoid a compiler warning. That's what gcc ends up | |
815 | * doing anyway. | |
816 | */ | |
817 | static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) | |
818 | { | |
819 | unsigned int depth = 0; | |
820 | ||
821 | while ((adapter = i2c_parent_is_i2c_adapter(adapter))) | |
822 | depth++; | |
823 | ||
824 | return depth; | |
825 | } | |
826 | ||
99cd8e25 JD |
827 | /* |
828 | * Let users instantiate I2C devices through sysfs. This can be used when | |
829 | * platform initialization code doesn't contain the proper data for | |
830 | * whatever reason. Also useful for drivers that do device detection and | |
831 | * detection fails, either because the device uses an unexpected address, | |
832 | * or this is a compatible device with different ID register values. | |
833 | * | |
834 | * Parameter checking may look overzealous, but we really don't want | |
835 | * the user to provide incorrect parameters. | |
836 | */ | |
837 | static ssize_t | |
838 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
839 | const char *buf, size_t count) | |
840 | { | |
841 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
842 | struct i2c_board_info info; | |
843 | struct i2c_client *client; | |
844 | char *blank, end; | |
845 | int res; | |
846 | ||
99cd8e25 JD |
847 | memset(&info, 0, sizeof(struct i2c_board_info)); |
848 | ||
849 | blank = strchr(buf, ' '); | |
850 | if (!blank) { | |
851 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
852 | return -EINVAL; | |
853 | } | |
854 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
855 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
856 | return -EINVAL; | |
857 | } | |
858 | memcpy(info.type, buf, blank - buf); | |
859 | ||
860 | /* Parse remaining parameters, reject extra parameters */ | |
861 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
862 | if (res < 1) { | |
863 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
864 | return -EINVAL; | |
865 | } | |
866 | if (res > 1 && end != '\n') { | |
867 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
868 | return -EINVAL; | |
869 | } | |
870 | ||
99cd8e25 JD |
871 | client = i2c_new_device(adap, &info); |
872 | if (!client) | |
3a89db5f | 873 | return -EINVAL; |
99cd8e25 JD |
874 | |
875 | /* Keep track of the added device */ | |
dafc50d1 | 876 | mutex_lock(&adap->userspace_clients_lock); |
6629dcff | 877 | list_add_tail(&client->detected, &adap->userspace_clients); |
dafc50d1 | 878 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
879 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
880 | info.type, info.addr); | |
881 | ||
882 | return count; | |
883 | } | |
884 | ||
885 | /* | |
886 | * And of course let the users delete the devices they instantiated, if | |
887 | * they got it wrong. This interface can only be used to delete devices | |
888 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
889 | * don't delete devices to which some kernel code still has references. | |
890 | * | |
891 | * Parameter checking may look overzealous, but we really don't want | |
892 | * the user to delete the wrong device. | |
893 | */ | |
894 | static ssize_t | |
895 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
896 | const char *buf, size_t count) | |
897 | { | |
898 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
899 | struct i2c_client *client, *next; | |
900 | unsigned short addr; | |
901 | char end; | |
902 | int res; | |
903 | ||
904 | /* Parse parameters, reject extra parameters */ | |
905 | res = sscanf(buf, "%hi%c", &addr, &end); | |
906 | if (res < 1) { | |
907 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
908 | return -EINVAL; | |
909 | } | |
910 | if (res > 1 && end != '\n') { | |
911 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
912 | return -EINVAL; | |
913 | } | |
914 | ||
915 | /* Make sure the device was added through sysfs */ | |
916 | res = -ENOENT; | |
390946b1 JD |
917 | mutex_lock_nested(&adap->userspace_clients_lock, |
918 | i2c_adapter_depth(adap)); | |
6629dcff JD |
919 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
920 | detected) { | |
921 | if (client->addr == addr) { | |
99cd8e25 JD |
922 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
923 | "delete_device", client->name, client->addr); | |
924 | ||
925 | list_del(&client->detected); | |
926 | i2c_unregister_device(client); | |
927 | res = count; | |
928 | break; | |
929 | } | |
930 | } | |
dafc50d1 | 931 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
932 | |
933 | if (res < 0) | |
934 | dev_err(dev, "%s: Can't find device in list\n", | |
935 | "delete_device"); | |
936 | return res; | |
937 | } | |
938 | ||
4f8cf824 | 939 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
e9b526fe AS |
940 | static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, |
941 | i2c_sysfs_delete_device); | |
4f8cf824 JD |
942 | |
943 | static struct attribute *i2c_adapter_attrs[] = { | |
944 | &dev_attr_name.attr, | |
945 | &dev_attr_new_device.attr, | |
946 | &dev_attr_delete_device.attr, | |
947 | NULL | |
948 | }; | |
949 | ||
950 | static struct attribute_group i2c_adapter_attr_group = { | |
951 | .attrs = i2c_adapter_attrs, | |
952 | }; | |
953 | ||
954 | static const struct attribute_group *i2c_adapter_attr_groups[] = { | |
955 | &i2c_adapter_attr_group, | |
956 | NULL | |
16ffadfc | 957 | }; |
b119dc3f | 958 | |
0826374b | 959 | struct device_type i2c_adapter_type = { |
4f8cf824 JD |
960 | .groups = i2c_adapter_attr_groups, |
961 | .release = i2c_adapter_dev_release, | |
1da177e4 | 962 | }; |
0826374b | 963 | EXPORT_SYMBOL_GPL(i2c_adapter_type); |
1da177e4 | 964 | |
643dd09e SW |
965 | /** |
966 | * i2c_verify_adapter - return parameter as i2c_adapter or NULL | |
967 | * @dev: device, probably from some driver model iterator | |
968 | * | |
969 | * When traversing the driver model tree, perhaps using driver model | |
970 | * iterators like @device_for_each_child(), you can't assume very much | |
971 | * about the nodes you find. Use this function to avoid oopses caused | |
972 | * by wrongly treating some non-I2C device as an i2c_adapter. | |
973 | */ | |
974 | struct i2c_adapter *i2c_verify_adapter(struct device *dev) | |
975 | { | |
976 | return (dev->type == &i2c_adapter_type) | |
977 | ? to_i2c_adapter(dev) | |
978 | : NULL; | |
979 | } | |
980 | EXPORT_SYMBOL(i2c_verify_adapter); | |
981 | ||
2bb5095a JD |
982 | #ifdef CONFIG_I2C_COMPAT |
983 | static struct class_compat *i2c_adapter_compat_class; | |
984 | #endif | |
985 | ||
9c1600ed DB |
986 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
987 | { | |
988 | struct i2c_devinfo *devinfo; | |
989 | ||
f18c41da | 990 | down_read(&__i2c_board_lock); |
9c1600ed DB |
991 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
992 | if (devinfo->busnum == adapter->nr | |
993 | && !i2c_new_device(adapter, | |
994 | &devinfo->board_info)) | |
09b8ce0a ZX |
995 | dev_err(&adapter->dev, |
996 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
997 | devinfo->board_info.addr); |
998 | } | |
f18c41da | 999 | up_read(&__i2c_board_lock); |
9c1600ed DB |
1000 | } |
1001 | ||
687b81d0 WS |
1002 | /* OF support code */ |
1003 | ||
1004 | #if IS_ENABLED(CONFIG_OF) | |
1005 | static void of_i2c_register_devices(struct i2c_adapter *adap) | |
1006 | { | |
1007 | void *result; | |
1008 | struct device_node *node; | |
1009 | ||
1010 | /* Only register child devices if the adapter has a node pointer set */ | |
1011 | if (!adap->dev.of_node) | |
1012 | return; | |
1013 | ||
1014 | dev_dbg(&adap->dev, "of_i2c: walking child nodes\n"); | |
1015 | ||
1016 | for_each_available_child_of_node(adap->dev.of_node, node) { | |
1017 | struct i2c_board_info info = {}; | |
1018 | struct dev_archdata dev_ad = {}; | |
1019 | const __be32 *addr; | |
1020 | int len; | |
1021 | ||
1022 | dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name); | |
1023 | ||
1024 | if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) { | |
1025 | dev_err(&adap->dev, "of_i2c: modalias failure on %s\n", | |
1026 | node->full_name); | |
1027 | continue; | |
1028 | } | |
1029 | ||
1030 | addr = of_get_property(node, "reg", &len); | |
1031 | if (!addr || (len < sizeof(int))) { | |
1032 | dev_err(&adap->dev, "of_i2c: invalid reg on %s\n", | |
1033 | node->full_name); | |
1034 | continue; | |
1035 | } | |
1036 | ||
1037 | info.addr = be32_to_cpup(addr); | |
1038 | if (info.addr > (1 << 10) - 1) { | |
1039 | dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n", | |
1040 | info.addr, node->full_name); | |
1041 | continue; | |
1042 | } | |
1043 | ||
1044 | info.irq = irq_of_parse_and_map(node, 0); | |
1045 | info.of_node = of_node_get(node); | |
1046 | info.archdata = &dev_ad; | |
1047 | ||
1048 | if (of_get_property(node, "wakeup-source", NULL)) | |
1049 | info.flags |= I2C_CLIENT_WAKE; | |
1050 | ||
1051 | request_module("%s%s", I2C_MODULE_PREFIX, info.type); | |
1052 | ||
1053 | result = i2c_new_device(adap, &info); | |
1054 | if (result == NULL) { | |
1055 | dev_err(&adap->dev, "of_i2c: Failure registering %s\n", | |
1056 | node->full_name); | |
1057 | of_node_put(node); | |
1058 | irq_dispose_mapping(info.irq); | |
1059 | continue; | |
1060 | } | |
1061 | } | |
1062 | } | |
1063 | ||
1064 | static int of_dev_node_match(struct device *dev, void *data) | |
1065 | { | |
1066 | return dev->of_node == data; | |
1067 | } | |
1068 | ||
1069 | /* must call put_device() when done with returned i2c_client device */ | |
1070 | struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) | |
1071 | { | |
1072 | struct device *dev; | |
1073 | ||
1074 | dev = bus_find_device(&i2c_bus_type, NULL, node, | |
1075 | of_dev_node_match); | |
1076 | if (!dev) | |
1077 | return NULL; | |
1078 | ||
1079 | return i2c_verify_client(dev); | |
1080 | } | |
1081 | EXPORT_SYMBOL(of_find_i2c_device_by_node); | |
1082 | ||
1083 | /* must call put_device() when done with returned i2c_adapter device */ | |
1084 | struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) | |
1085 | { | |
1086 | struct device *dev; | |
1087 | ||
1088 | dev = bus_find_device(&i2c_bus_type, NULL, node, | |
1089 | of_dev_node_match); | |
1090 | if (!dev) | |
1091 | return NULL; | |
1092 | ||
1093 | return i2c_verify_adapter(dev); | |
1094 | } | |
1095 | EXPORT_SYMBOL(of_find_i2c_adapter_by_node); | |
1096 | #else | |
1097 | static void of_i2c_register_devices(struct i2c_adapter *adap) { } | |
1098 | #endif /* CONFIG_OF */ | |
1099 | ||
69b0089a JD |
1100 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
1101 | struct i2c_adapter *adap) | |
026526f5 | 1102 | { |
4735c98f JD |
1103 | /* Detect supported devices on that bus, and instantiate them */ |
1104 | i2c_detect(adap, driver); | |
1105 | ||
1106 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 | 1107 | if (driver->attach_adapter) { |
a920ff41 JD |
1108 | dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n", |
1109 | driver->driver.name); | |
fe6fc258 JD |
1110 | dev_warn(&adap->dev, "Please use another way to instantiate " |
1111 | "your i2c_client\n"); | |
026526f5 JD |
1112 | /* We ignore the return code; if it fails, too bad */ |
1113 | driver->attach_adapter(adap); | |
1114 | } | |
1115 | return 0; | |
1116 | } | |
1117 | ||
69b0089a JD |
1118 | static int __process_new_adapter(struct device_driver *d, void *data) |
1119 | { | |
1120 | return i2c_do_add_adapter(to_i2c_driver(d), data); | |
1121 | } | |
1122 | ||
6e13e641 | 1123 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 1124 | { |
d6703281 | 1125 | int res = 0; |
1da177e4 | 1126 | |
1d0b19c9 | 1127 | /* Can't register until after driver model init */ |
35fc37f8 JD |
1128 | if (unlikely(WARN_ON(!i2c_bus_type.p))) { |
1129 | res = -EAGAIN; | |
1130 | goto out_list; | |
1131 | } | |
1d0b19c9 | 1132 | |
2236baa7 JD |
1133 | /* Sanity checks */ |
1134 | if (unlikely(adap->name[0] == '\0')) { | |
1135 | pr_err("i2c-core: Attempt to register an adapter with " | |
1136 | "no name!\n"); | |
1137 | return -EINVAL; | |
1138 | } | |
1139 | if (unlikely(!adap->algo)) { | |
1140 | pr_err("i2c-core: Attempt to register adapter '%s' with " | |
1141 | "no algo!\n", adap->name); | |
1142 | return -EINVAL; | |
1143 | } | |
1144 | ||
194684e5 | 1145 | rt_mutex_init(&adap->bus_lock); |
dafc50d1 | 1146 | mutex_init(&adap->userspace_clients_lock); |
6629dcff | 1147 | INIT_LIST_HEAD(&adap->userspace_clients); |
1da177e4 | 1148 | |
8fcfef6e JD |
1149 | /* Set default timeout to 1 second if not already set */ |
1150 | if (adap->timeout == 0) | |
1151 | adap->timeout = HZ; | |
1152 | ||
27d9c183 | 1153 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
1154 | adap->dev.bus = &i2c_bus_type; |
1155 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 JD |
1156 | res = device_register(&adap->dev); |
1157 | if (res) | |
1158 | goto out_list; | |
1da177e4 | 1159 | |
b6d7b3d1 JD |
1160 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
1161 | ||
2bb5095a JD |
1162 | #ifdef CONFIG_I2C_COMPAT |
1163 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
1164 | adap->dev.parent); | |
1165 | if (res) | |
1166 | dev_warn(&adap->dev, | |
1167 | "Failed to create compatibility class link\n"); | |
1168 | #endif | |
1169 | ||
5f9296ba VK |
1170 | /* bus recovery specific initialization */ |
1171 | if (adap->bus_recovery_info) { | |
1172 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
1173 | ||
1174 | if (!bri->recover_bus) { | |
1175 | dev_err(&adap->dev, "No recover_bus() found, not using recovery\n"); | |
1176 | adap->bus_recovery_info = NULL; | |
1177 | goto exit_recovery; | |
1178 | } | |
1179 | ||
1180 | /* Generic GPIO recovery */ | |
1181 | if (bri->recover_bus == i2c_generic_gpio_recovery) { | |
1182 | if (!gpio_is_valid(bri->scl_gpio)) { | |
1183 | dev_err(&adap->dev, "Invalid SCL gpio, not using recovery\n"); | |
1184 | adap->bus_recovery_info = NULL; | |
1185 | goto exit_recovery; | |
1186 | } | |
1187 | ||
1188 | if (gpio_is_valid(bri->sda_gpio)) | |
1189 | bri->get_sda = get_sda_gpio_value; | |
1190 | else | |
1191 | bri->get_sda = NULL; | |
1192 | ||
1193 | bri->get_scl = get_scl_gpio_value; | |
1194 | bri->set_scl = set_scl_gpio_value; | |
1195 | } else if (!bri->set_scl || !bri->get_scl) { | |
1196 | /* Generic SCL recovery */ | |
1197 | dev_err(&adap->dev, "No {get|set}_gpio() found, not using recovery\n"); | |
1198 | adap->bus_recovery_info = NULL; | |
1199 | } | |
1200 | } | |
1201 | ||
1202 | exit_recovery: | |
729d6dd5 | 1203 | /* create pre-declared device nodes */ |
687b81d0 | 1204 | of_i2c_register_devices(adap); |
55e71edb | 1205 | acpi_i2c_register_devices(adap); |
5d98e61d | 1206 | acpi_i2c_install_space_handler(adap); |
687b81d0 | 1207 | |
6e13e641 DB |
1208 | if (adap->nr < __i2c_first_dynamic_bus_num) |
1209 | i2c_scan_static_board_info(adap); | |
1210 | ||
4735c98f | 1211 | /* Notify drivers */ |
35fc37f8 | 1212 | mutex_lock(&core_lock); |
d6703281 | 1213 | bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); |
caada32a | 1214 | mutex_unlock(&core_lock); |
35fc37f8 JD |
1215 | |
1216 | return 0; | |
b119c6c9 | 1217 | |
b119c6c9 | 1218 | out_list: |
35fc37f8 | 1219 | mutex_lock(&core_lock); |
b119c6c9 | 1220 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
1221 | mutex_unlock(&core_lock); |
1222 | return res; | |
1da177e4 LT |
1223 | } |
1224 | ||
ee5c2744 DA |
1225 | /** |
1226 | * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 | |
1227 | * @adap: the adapter to register (with adap->nr initialized) | |
1228 | * Context: can sleep | |
1229 | * | |
1230 | * See i2c_add_numbered_adapter() for details. | |
1231 | */ | |
1232 | static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1233 | { | |
1234 | int id; | |
1235 | ||
1236 | mutex_lock(&core_lock); | |
1237 | id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, | |
1238 | GFP_KERNEL); | |
1239 | mutex_unlock(&core_lock); | |
1240 | if (id < 0) | |
1241 | return id == -ENOSPC ? -EBUSY : id; | |
1242 | ||
1243 | return i2c_register_adapter(adap); | |
1244 | } | |
1245 | ||
6e13e641 DB |
1246 | /** |
1247 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
1248 | * @adapter: the adapter to add | |
d64f73be | 1249 | * Context: can sleep |
6e13e641 DB |
1250 | * |
1251 | * This routine is used to declare an I2C adapter when its bus number | |
ee5c2744 DA |
1252 | * doesn't matter or when its bus number is specified by an dt alias. |
1253 | * Examples of bases when the bus number doesn't matter: I2C adapters | |
1254 | * dynamically added by USB links or PCI plugin cards. | |
6e13e641 DB |
1255 | * |
1256 | * When this returns zero, a new bus number was allocated and stored | |
1257 | * in adap->nr, and the specified adapter became available for clients. | |
1258 | * Otherwise, a negative errno value is returned. | |
1259 | */ | |
1260 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
1261 | { | |
ee5c2744 | 1262 | struct device *dev = &adapter->dev; |
4ae42b0f | 1263 | int id; |
6e13e641 | 1264 | |
ee5c2744 DA |
1265 | if (dev->of_node) { |
1266 | id = of_alias_get_id(dev->of_node, "i2c"); | |
1267 | if (id >= 0) { | |
1268 | adapter->nr = id; | |
1269 | return __i2c_add_numbered_adapter(adapter); | |
1270 | } | |
1271 | } | |
1272 | ||
caada32a | 1273 | mutex_lock(&core_lock); |
4ae42b0f TH |
1274 | id = idr_alloc(&i2c_adapter_idr, adapter, |
1275 | __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); | |
caada32a | 1276 | mutex_unlock(&core_lock); |
4ae42b0f TH |
1277 | if (id < 0) |
1278 | return id; | |
6e13e641 DB |
1279 | |
1280 | adapter->nr = id; | |
4ae42b0f | 1281 | |
6e13e641 DB |
1282 | return i2c_register_adapter(adapter); |
1283 | } | |
1284 | EXPORT_SYMBOL(i2c_add_adapter); | |
1285 | ||
1286 | /** | |
1287 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
1288 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 1289 | * Context: can sleep |
6e13e641 DB |
1290 | * |
1291 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
1292 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
1293 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
1294 | * is used to properly configure I2C devices. |
1295 | * | |
488bf314 GL |
1296 | * If the requested bus number is set to -1, then this function will behave |
1297 | * identically to i2c_add_adapter, and will dynamically assign a bus number. | |
1298 | * | |
6e13e641 DB |
1299 | * If no devices have pre-been declared for this bus, then be sure to |
1300 | * register the adapter before any dynamically allocated ones. Otherwise | |
1301 | * the required bus ID may not be available. | |
1302 | * | |
1303 | * When this returns zero, the specified adapter became available for | |
1304 | * clients using the bus number provided in adap->nr. Also, the table | |
1305 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
1306 | * and the appropriate driver model device nodes are created. Otherwise, a | |
1307 | * negative errno value is returned. | |
1308 | */ | |
1309 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1310 | { | |
488bf314 GL |
1311 | if (adap->nr == -1) /* -1 means dynamically assign bus id */ |
1312 | return i2c_add_adapter(adap); | |
6e13e641 | 1313 | |
ee5c2744 | 1314 | return __i2c_add_numbered_adapter(adap); |
6e13e641 DB |
1315 | } |
1316 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
1317 | ||
19baba4c | 1318 | static void i2c_do_del_adapter(struct i2c_driver *driver, |
69b0089a | 1319 | struct i2c_adapter *adapter) |
026526f5 | 1320 | { |
4735c98f | 1321 | struct i2c_client *client, *_n; |
026526f5 | 1322 | |
acec211c JD |
1323 | /* Remove the devices we created ourselves as the result of hardware |
1324 | * probing (using a driver's detect method) */ | |
4735c98f JD |
1325 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
1326 | if (client->adapter == adapter) { | |
1327 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
1328 | client->name, client->addr); | |
1329 | list_del(&client->detected); | |
1330 | i2c_unregister_device(client); | |
1331 | } | |
1332 | } | |
026526f5 JD |
1333 | } |
1334 | ||
e549c2b5 | 1335 | static int __unregister_client(struct device *dev, void *dummy) |
5219bf88 JD |
1336 | { |
1337 | struct i2c_client *client = i2c_verify_client(dev); | |
1338 | if (client && strcmp(client->name, "dummy")) | |
1339 | i2c_unregister_device(client); | |
1340 | return 0; | |
1341 | } | |
1342 | ||
1343 | static int __unregister_dummy(struct device *dev, void *dummy) | |
e549c2b5 JD |
1344 | { |
1345 | struct i2c_client *client = i2c_verify_client(dev); | |
1346 | if (client) | |
1347 | i2c_unregister_device(client); | |
1348 | return 0; | |
1349 | } | |
1350 | ||
69b0089a JD |
1351 | static int __process_removed_adapter(struct device_driver *d, void *data) |
1352 | { | |
19baba4c LPC |
1353 | i2c_do_del_adapter(to_i2c_driver(d), data); |
1354 | return 0; | |
69b0089a JD |
1355 | } |
1356 | ||
d64f73be DB |
1357 | /** |
1358 | * i2c_del_adapter - unregister I2C adapter | |
1359 | * @adap: the adapter being unregistered | |
1360 | * Context: can sleep | |
1361 | * | |
1362 | * This unregisters an I2C adapter which was previously registered | |
1363 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
1364 | */ | |
71546300 | 1365 | void i2c_del_adapter(struct i2c_adapter *adap) |
1da177e4 | 1366 | { |
35fc37f8 | 1367 | struct i2c_adapter *found; |
bbd2d9c9 | 1368 | struct i2c_client *client, *next; |
1da177e4 LT |
1369 | |
1370 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
1371 | mutex_lock(&core_lock); |
1372 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
1373 | mutex_unlock(&core_lock); | |
1374 | if (found != adap) { | |
b6d7b3d1 JD |
1375 | pr_debug("i2c-core: attempting to delete unregistered " |
1376 | "adapter [%s]\n", adap->name); | |
71546300 | 1377 | return; |
1da177e4 LT |
1378 | } |
1379 | ||
5d98e61d | 1380 | acpi_i2c_remove_space_handler(adap); |
026526f5 | 1381 | /* Tell drivers about this removal */ |
35fc37f8 | 1382 | mutex_lock(&core_lock); |
19baba4c | 1383 | bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 1384 | __process_removed_adapter); |
35fc37f8 | 1385 | mutex_unlock(&core_lock); |
1da177e4 | 1386 | |
bbd2d9c9 | 1387 | /* Remove devices instantiated from sysfs */ |
390946b1 JD |
1388 | mutex_lock_nested(&adap->userspace_clients_lock, |
1389 | i2c_adapter_depth(adap)); | |
6629dcff JD |
1390 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1391 | detected) { | |
1392 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, | |
1393 | client->addr); | |
1394 | list_del(&client->detected); | |
1395 | i2c_unregister_device(client); | |
bbd2d9c9 | 1396 | } |
dafc50d1 | 1397 | mutex_unlock(&adap->userspace_clients_lock); |
bbd2d9c9 | 1398 | |
e549c2b5 | 1399 | /* Detach any active clients. This can't fail, thus we do not |
5219bf88 JD |
1400 | * check the returned value. This is a two-pass process, because |
1401 | * we can't remove the dummy devices during the first pass: they | |
1402 | * could have been instantiated by real devices wishing to clean | |
1403 | * them up properly, so we give them a chance to do that first. */ | |
19baba4c LPC |
1404 | device_for_each_child(&adap->dev, NULL, __unregister_client); |
1405 | device_for_each_child(&adap->dev, NULL, __unregister_dummy); | |
1da177e4 | 1406 | |
2bb5095a JD |
1407 | #ifdef CONFIG_I2C_COMPAT |
1408 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
1409 | adap->dev.parent); | |
1410 | #endif | |
1411 | ||
c5567521 TLSC |
1412 | /* device name is gone after device_unregister */ |
1413 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); | |
1414 | ||
1da177e4 LT |
1415 | /* clean up the sysfs representation */ |
1416 | init_completion(&adap->dev_released); | |
1da177e4 | 1417 | device_unregister(&adap->dev); |
1da177e4 LT |
1418 | |
1419 | /* wait for sysfs to drop all references */ | |
1420 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 1421 | |
6e13e641 | 1422 | /* free bus id */ |
35fc37f8 | 1423 | mutex_lock(&core_lock); |
1da177e4 | 1424 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 1425 | mutex_unlock(&core_lock); |
1da177e4 | 1426 | |
bd4bc3db JD |
1427 | /* Clear the device structure in case this adapter is ever going to be |
1428 | added again */ | |
1429 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
1da177e4 | 1430 | } |
c0564606 | 1431 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 | 1432 | |
7b4fbc50 DB |
1433 | /* ------------------------------------------------------------------------- */ |
1434 | ||
7ae31482 JD |
1435 | int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) |
1436 | { | |
1437 | int res; | |
1438 | ||
1439 | mutex_lock(&core_lock); | |
1440 | res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); | |
1441 | mutex_unlock(&core_lock); | |
1442 | ||
1443 | return res; | |
1444 | } | |
1445 | EXPORT_SYMBOL_GPL(i2c_for_each_dev); | |
1446 | ||
69b0089a | 1447 | static int __process_new_driver(struct device *dev, void *data) |
7f101a97 | 1448 | { |
4f8cf824 JD |
1449 | if (dev->type != &i2c_adapter_type) |
1450 | return 0; | |
69b0089a | 1451 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
7f101a97 DY |
1452 | } |
1453 | ||
7b4fbc50 DB |
1454 | /* |
1455 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 1456 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
1457 | */ |
1458 | ||
de59cf9e | 1459 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 1460 | { |
7eebcb7c | 1461 | int res; |
1da177e4 | 1462 | |
1d0b19c9 DB |
1463 | /* Can't register until after driver model init */ |
1464 | if (unlikely(WARN_ON(!i2c_bus_type.p))) | |
1465 | return -EAGAIN; | |
1466 | ||
1da177e4 | 1467 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 1468 | driver->driver.owner = owner; |
1da177e4 | 1469 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 1470 | |
729d6dd5 | 1471 | /* When registration returns, the driver core |
6e13e641 DB |
1472 | * will have called probe() for all matching-but-unbound devices. |
1473 | */ | |
1da177e4 LT |
1474 | res = driver_register(&driver->driver); |
1475 | if (res) | |
7eebcb7c | 1476 | return res; |
438d6c2c | 1477 | |
f4e8db31 MB |
1478 | /* Drivers should switch to dev_pm_ops instead. */ |
1479 | if (driver->suspend) | |
1480 | pr_warn("i2c-core: driver [%s] using legacy suspend method\n", | |
1481 | driver->driver.name); | |
1482 | if (driver->resume) | |
1483 | pr_warn("i2c-core: driver [%s] using legacy resume method\n", | |
1484 | driver->driver.name); | |
1485 | ||
35d8b2e6 | 1486 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 1487 | |
4735c98f JD |
1488 | INIT_LIST_HEAD(&driver->clients); |
1489 | /* Walk the adapters that are already present */ | |
7ae31482 | 1490 | i2c_for_each_dev(driver, __process_new_driver); |
35fc37f8 | 1491 | |
7f101a97 DY |
1492 | return 0; |
1493 | } | |
1494 | EXPORT_SYMBOL(i2c_register_driver); | |
1495 | ||
69b0089a | 1496 | static int __process_removed_driver(struct device *dev, void *data) |
7f101a97 | 1497 | { |
19baba4c LPC |
1498 | if (dev->type == &i2c_adapter_type) |
1499 | i2c_do_del_adapter(data, to_i2c_adapter(dev)); | |
1500 | return 0; | |
1da177e4 LT |
1501 | } |
1502 | ||
a1d9e6e4 DB |
1503 | /** |
1504 | * i2c_del_driver - unregister I2C driver | |
1505 | * @driver: the driver being unregistered | |
d64f73be | 1506 | * Context: can sleep |
a1d9e6e4 | 1507 | */ |
b3e82096 | 1508 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 1509 | { |
7ae31482 | 1510 | i2c_for_each_dev(driver, __process_removed_driver); |
1da177e4 LT |
1511 | |
1512 | driver_unregister(&driver->driver); | |
35d8b2e6 | 1513 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 1514 | } |
c0564606 | 1515 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 1516 | |
7b4fbc50 DB |
1517 | /* ------------------------------------------------------------------------- */ |
1518 | ||
e48d3319 JD |
1519 | /** |
1520 | * i2c_use_client - increments the reference count of the i2c client structure | |
1521 | * @client: the client being referenced | |
1522 | * | |
1523 | * Each live reference to a client should be refcounted. The driver model does | |
1524 | * that automatically as part of driver binding, so that most drivers don't | |
1525 | * need to do this explicitly: they hold a reference until they're unbound | |
1526 | * from the device. | |
1527 | * | |
1528 | * A pointer to the client with the incremented reference counter is returned. | |
1529 | */ | |
1530 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 1531 | { |
6ea438ec DB |
1532 | if (client && get_device(&client->dev)) |
1533 | return client; | |
1534 | return NULL; | |
1da177e4 | 1535 | } |
c0564606 | 1536 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 1537 | |
e48d3319 JD |
1538 | /** |
1539 | * i2c_release_client - release a use of the i2c client structure | |
1540 | * @client: the client being no longer referenced | |
1541 | * | |
1542 | * Must be called when a user of a client is finished with it. | |
1543 | */ | |
1544 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 1545 | { |
6ea438ec DB |
1546 | if (client) |
1547 | put_device(&client->dev); | |
1da177e4 | 1548 | } |
c0564606 | 1549 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 1550 | |
9b766b81 DB |
1551 | struct i2c_cmd_arg { |
1552 | unsigned cmd; | |
1553 | void *arg; | |
1554 | }; | |
1555 | ||
1556 | static int i2c_cmd(struct device *dev, void *_arg) | |
1557 | { | |
1558 | struct i2c_client *client = i2c_verify_client(dev); | |
1559 | struct i2c_cmd_arg *arg = _arg; | |
0acc2b32 LPC |
1560 | struct i2c_driver *driver; |
1561 | ||
1562 | if (!client || !client->dev.driver) | |
1563 | return 0; | |
9b766b81 | 1564 | |
0acc2b32 LPC |
1565 | driver = to_i2c_driver(client->dev.driver); |
1566 | if (driver->command) | |
1567 | driver->command(client, arg->cmd, arg->arg); | |
9b766b81 DB |
1568 | return 0; |
1569 | } | |
1570 | ||
1da177e4 LT |
1571 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
1572 | { | |
9b766b81 | 1573 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 1574 | |
9b766b81 DB |
1575 | cmd_arg.cmd = cmd; |
1576 | cmd_arg.arg = arg; | |
1577 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 1578 | } |
c0564606 | 1579 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
1580 | |
1581 | static int __init i2c_init(void) | |
1582 | { | |
1583 | int retval; | |
1584 | ||
1585 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
1586 | if (retval) |
1587 | return retval; | |
2bb5095a JD |
1588 | #ifdef CONFIG_I2C_COMPAT |
1589 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
1590 | if (!i2c_adapter_compat_class) { | |
1591 | retval = -ENOMEM; | |
1592 | goto bus_err; | |
1593 | } | |
1594 | #endif | |
e9f1373b DB |
1595 | retval = i2c_add_driver(&dummy_driver); |
1596 | if (retval) | |
2bb5095a | 1597 | goto class_err; |
e9f1373b DB |
1598 | return 0; |
1599 | ||
2bb5095a JD |
1600 | class_err: |
1601 | #ifdef CONFIG_I2C_COMPAT | |
1602 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 1603 | bus_err: |
2bb5095a | 1604 | #endif |
e9f1373b DB |
1605 | bus_unregister(&i2c_bus_type); |
1606 | return retval; | |
1da177e4 LT |
1607 | } |
1608 | ||
1609 | static void __exit i2c_exit(void) | |
1610 | { | |
e9f1373b | 1611 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
1612 | #ifdef CONFIG_I2C_COMPAT |
1613 | class_compat_unregister(i2c_adapter_compat_class); | |
1614 | #endif | |
1da177e4 | 1615 | bus_unregister(&i2c_bus_type); |
d9a83d62 | 1616 | tracepoint_synchronize_unregister(); |
1da177e4 LT |
1617 | } |
1618 | ||
a10f9e7c DB |
1619 | /* We must initialize early, because some subsystems register i2c drivers |
1620 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1621 | */ | |
1622 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1623 | module_exit(i2c_exit); |
1624 | ||
1625 | /* ---------------------------------------------------- | |
1626 | * the functional interface to the i2c busses. | |
1627 | * ---------------------------------------------------- | |
1628 | */ | |
1629 | ||
b37d2a3a JD |
1630 | /** |
1631 | * __i2c_transfer - unlocked flavor of i2c_transfer | |
1632 | * @adap: Handle to I2C bus | |
1633 | * @msgs: One or more messages to execute before STOP is issued to | |
1634 | * terminate the operation; each message begins with a START. | |
1635 | * @num: Number of messages to be executed. | |
1636 | * | |
1637 | * Returns negative errno, else the number of messages executed. | |
1638 | * | |
1639 | * Adapter lock must be held when calling this function. No debug logging | |
1640 | * takes place. adap->algo->master_xfer existence isn't checked. | |
1641 | */ | |
1642 | int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
1643 | { | |
1644 | unsigned long orig_jiffies; | |
1645 | int ret, try; | |
1646 | ||
d9a83d62 DH |
1647 | /* i2c_trace_msg gets enabled when tracepoint i2c_transfer gets |
1648 | * enabled. This is an efficient way of keeping the for-loop from | |
1649 | * being executed when not needed. | |
1650 | */ | |
1651 | if (static_key_false(&i2c_trace_msg)) { | |
1652 | int i; | |
1653 | for (i = 0; i < num; i++) | |
1654 | if (msgs[i].flags & I2C_M_RD) | |
1655 | trace_i2c_read(adap, &msgs[i], i); | |
1656 | else | |
1657 | trace_i2c_write(adap, &msgs[i], i); | |
1658 | } | |
1659 | ||
b37d2a3a JD |
1660 | /* Retry automatically on arbitration loss */ |
1661 | orig_jiffies = jiffies; | |
1662 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
1663 | ret = adap->algo->master_xfer(adap, msgs, num); | |
1664 | if (ret != -EAGAIN) | |
1665 | break; | |
1666 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
1667 | break; | |
1668 | } | |
1669 | ||
d9a83d62 DH |
1670 | if (static_key_false(&i2c_trace_msg)) { |
1671 | int i; | |
1672 | for (i = 0; i < ret; i++) | |
1673 | if (msgs[i].flags & I2C_M_RD) | |
1674 | trace_i2c_reply(adap, &msgs[i], i); | |
1675 | trace_i2c_result(adap, i, ret); | |
1676 | } | |
1677 | ||
b37d2a3a JD |
1678 | return ret; |
1679 | } | |
1680 | EXPORT_SYMBOL(__i2c_transfer); | |
1681 | ||
a1cdedac DB |
1682 | /** |
1683 | * i2c_transfer - execute a single or combined I2C message | |
1684 | * @adap: Handle to I2C bus | |
1685 | * @msgs: One or more messages to execute before STOP is issued to | |
1686 | * terminate the operation; each message begins with a START. | |
1687 | * @num: Number of messages to be executed. | |
1688 | * | |
1689 | * Returns negative errno, else the number of messages executed. | |
1690 | * | |
1691 | * Note that there is no requirement that each message be sent to | |
1692 | * the same slave address, although that is the most common model. | |
1693 | */ | |
09b8ce0a | 1694 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 1695 | { |
b37d2a3a | 1696 | int ret; |
1da177e4 | 1697 | |
a1cdedac DB |
1698 | /* REVISIT the fault reporting model here is weak: |
1699 | * | |
1700 | * - When we get an error after receiving N bytes from a slave, | |
1701 | * there is no way to report "N". | |
1702 | * | |
1703 | * - When we get a NAK after transmitting N bytes to a slave, | |
1704 | * there is no way to report "N" ... or to let the master | |
1705 | * continue executing the rest of this combined message, if | |
1706 | * that's the appropriate response. | |
1707 | * | |
1708 | * - When for example "num" is two and we successfully complete | |
1709 | * the first message but get an error part way through the | |
1710 | * second, it's unclear whether that should be reported as | |
1711 | * one (discarding status on the second message) or errno | |
1712 | * (discarding status on the first one). | |
1713 | */ | |
1714 | ||
1da177e4 LT |
1715 | if (adap->algo->master_xfer) { |
1716 | #ifdef DEBUG | |
1717 | for (ret = 0; ret < num; ret++) { | |
1718 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
1719 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
1720 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
1721 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
1722 | } |
1723 | #endif | |
1724 | ||
cea443a8 | 1725 | if (in_atomic() || irqs_disabled()) { |
fe61e07e | 1726 | ret = i2c_trylock_adapter(adap); |
cea443a8 MR |
1727 | if (!ret) |
1728 | /* I2C activity is ongoing. */ | |
1729 | return -EAGAIN; | |
1730 | } else { | |
fe61e07e | 1731 | i2c_lock_adapter(adap); |
cea443a8 MR |
1732 | } |
1733 | ||
b37d2a3a | 1734 | ret = __i2c_transfer(adap, msgs, num); |
fe61e07e | 1735 | i2c_unlock_adapter(adap); |
1da177e4 LT |
1736 | |
1737 | return ret; | |
1738 | } else { | |
1739 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1740 | return -EOPNOTSUPP; |
1da177e4 LT |
1741 | } |
1742 | } | |
c0564606 | 1743 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1744 | |
a1cdedac DB |
1745 | /** |
1746 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1747 | * @client: Handle to slave device | |
1748 | * @buf: Data that will be written to the slave | |
0c43ea54 | 1749 | * @count: How many bytes to write, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1750 | * |
1751 | * Returns negative errno, or else the number of bytes written. | |
1752 | */ | |
0cc43a18 | 1753 | int i2c_master_send(const struct i2c_client *client, const char *buf, int count) |
1da177e4 LT |
1754 | { |
1755 | int ret; | |
7225acf4 | 1756 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1757 | struct i2c_msg msg; |
1758 | ||
815f55f2 JD |
1759 | msg.addr = client->addr; |
1760 | msg.flags = client->flags & I2C_M_TEN; | |
1761 | msg.len = count; | |
1762 | msg.buf = (char *)buf; | |
438d6c2c | 1763 | |
815f55f2 | 1764 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1765 | |
834aa6f3 WS |
1766 | /* |
1767 | * If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1768 | * transmitted, else error code. | |
1769 | */ | |
815f55f2 | 1770 | return (ret == 1) ? count : ret; |
1da177e4 | 1771 | } |
c0564606 | 1772 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1773 | |
a1cdedac DB |
1774 | /** |
1775 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1776 | * @client: Handle to slave device | |
1777 | * @buf: Where to store data read from slave | |
0c43ea54 | 1778 | * @count: How many bytes to read, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1779 | * |
1780 | * Returns negative errno, or else the number of bytes read. | |
1781 | */ | |
0cc43a18 | 1782 | int i2c_master_recv(const struct i2c_client *client, char *buf, int count) |
1da177e4 | 1783 | { |
7225acf4 | 1784 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1785 | struct i2c_msg msg; |
1786 | int ret; | |
815f55f2 JD |
1787 | |
1788 | msg.addr = client->addr; | |
1789 | msg.flags = client->flags & I2C_M_TEN; | |
1790 | msg.flags |= I2C_M_RD; | |
1791 | msg.len = count; | |
1792 | msg.buf = buf; | |
1793 | ||
1794 | ret = i2c_transfer(adap, &msg, 1); | |
1795 | ||
834aa6f3 WS |
1796 | /* |
1797 | * If everything went ok (i.e. 1 msg received), return #bytes received, | |
1798 | * else error code. | |
1799 | */ | |
815f55f2 | 1800 | return (ret == 1) ? count : ret; |
1da177e4 | 1801 | } |
c0564606 | 1802 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1803 | |
1da177e4 LT |
1804 | /* ---------------------------------------------------- |
1805 | * the i2c address scanning function | |
1806 | * Will not work for 10-bit addresses! | |
1807 | * ---------------------------------------------------- | |
1808 | */ | |
1da177e4 | 1809 | |
63e4e802 JD |
1810 | /* |
1811 | * Legacy default probe function, mostly relevant for SMBus. The default | |
1812 | * probe method is a quick write, but it is known to corrupt the 24RF08 | |
1813 | * EEPROMs due to a state machine bug, and could also irreversibly | |
1814 | * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, | |
1815 | * we use a short byte read instead. Also, some bus drivers don't implement | |
1816 | * quick write, so we fallback to a byte read in that case too. | |
1817 | * On x86, there is another special case for FSC hardware monitoring chips, | |
1818 | * which want regular byte reads (address 0x73.) Fortunately, these are the | |
1819 | * only known chips using this I2C address on PC hardware. | |
1820 | * Returns 1 if probe succeeded, 0 if not. | |
1821 | */ | |
1822 | static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) | |
1823 | { | |
1824 | int err; | |
1825 | union i2c_smbus_data dummy; | |
1826 | ||
1827 | #ifdef CONFIG_X86 | |
1828 | if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) | |
1829 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) | |
1830 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1831 | I2C_SMBUS_BYTE_DATA, &dummy); | |
1832 | else | |
1833 | #endif | |
8031d79b JD |
1834 | if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) |
1835 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) | |
63e4e802 JD |
1836 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, |
1837 | I2C_SMBUS_QUICK, NULL); | |
8031d79b JD |
1838 | else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) |
1839 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1840 | I2C_SMBUS_BYTE, &dummy); | |
1841 | else { | |
d63a9e85 AL |
1842 | dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", |
1843 | addr); | |
8031d79b JD |
1844 | err = -EOPNOTSUPP; |
1845 | } | |
63e4e802 JD |
1846 | |
1847 | return err >= 0; | |
1848 | } | |
1849 | ||
ccfbbd08 | 1850 | static int i2c_detect_address(struct i2c_client *temp_client, |
4735c98f JD |
1851 | struct i2c_driver *driver) |
1852 | { | |
1853 | struct i2c_board_info info; | |
1854 | struct i2c_adapter *adapter = temp_client->adapter; | |
1855 | int addr = temp_client->addr; | |
1856 | int err; | |
1857 | ||
1858 | /* Make sure the address is valid */ | |
656b8761 JD |
1859 | err = i2c_check_addr_validity(addr); |
1860 | if (err) { | |
4735c98f JD |
1861 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
1862 | addr); | |
656b8761 | 1863 | return err; |
4735c98f JD |
1864 | } |
1865 | ||
1866 | /* Skip if already in use */ | |
3b5f794b | 1867 | if (i2c_check_addr_busy(adapter, addr)) |
4735c98f JD |
1868 | return 0; |
1869 | ||
ccfbbd08 | 1870 | /* Make sure there is something at this address */ |
63e4e802 JD |
1871 | if (!i2c_default_probe(adapter, addr)) |
1872 | return 0; | |
4735c98f JD |
1873 | |
1874 | /* Finally call the custom detection function */ | |
1875 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
1876 | info.addr = addr; | |
310ec792 | 1877 | err = driver->detect(temp_client, &info); |
4735c98f JD |
1878 | if (err) { |
1879 | /* -ENODEV is returned if the detection fails. We catch it | |
1880 | here as this isn't an error. */ | |
1881 | return err == -ENODEV ? 0 : err; | |
1882 | } | |
1883 | ||
1884 | /* Consistency check */ | |
1885 | if (info.type[0] == '\0') { | |
1886 | dev_err(&adapter->dev, "%s detection function provided " | |
1887 | "no name for 0x%x\n", driver->driver.name, | |
1888 | addr); | |
1889 | } else { | |
1890 | struct i2c_client *client; | |
1891 | ||
1892 | /* Detection succeeded, instantiate the device */ | |
0c176170 WS |
1893 | if (adapter->class & I2C_CLASS_DEPRECATED) |
1894 | dev_warn(&adapter->dev, | |
1895 | "This adapter will soon drop class based instantiation of devices. " | |
1896 | "Please make sure client 0x%02x gets instantiated by other means. " | |
1897 | "Check 'Documentation/i2c/instantiating-devices' for details.\n", | |
1898 | info.addr); | |
1899 | ||
4735c98f JD |
1900 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", |
1901 | info.type, info.addr); | |
1902 | client = i2c_new_device(adapter, &info); | |
1903 | if (client) | |
1904 | list_add_tail(&client->detected, &driver->clients); | |
1905 | else | |
1906 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
1907 | info.type, info.addr); | |
1908 | } | |
1909 | return 0; | |
1910 | } | |
1911 | ||
1912 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
1913 | { | |
c3813d6a | 1914 | const unsigned short *address_list; |
4735c98f JD |
1915 | struct i2c_client *temp_client; |
1916 | int i, err = 0; | |
1917 | int adap_id = i2c_adapter_id(adapter); | |
1918 | ||
c3813d6a JD |
1919 | address_list = driver->address_list; |
1920 | if (!driver->detect || !address_list) | |
4735c98f JD |
1921 | return 0; |
1922 | ||
45552272 WS |
1923 | /* Warn that the adapter lost class based instantiation */ |
1924 | if (adapter->class == I2C_CLASS_DEPRECATED) { | |
1925 | dev_dbg(&adapter->dev, | |
1926 | "This adapter dropped support for I2C classes and " | |
1927 | "won't auto-detect %s devices anymore. If you need it, check " | |
1928 | "'Documentation/i2c/instantiating-devices' for alternatives.\n", | |
1929 | driver->driver.name); | |
1930 | return 0; | |
1931 | } | |
1932 | ||
51b54ba9 JD |
1933 | /* Stop here if the classes do not match */ |
1934 | if (!(adapter->class & driver->class)) | |
1935 | return 0; | |
1936 | ||
4735c98f JD |
1937 | /* Set up a temporary client to help detect callback */ |
1938 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
1939 | if (!temp_client) | |
1940 | return -ENOMEM; | |
1941 | temp_client->adapter = adapter; | |
1942 | ||
c3813d6a | 1943 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
4735c98f | 1944 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
c3813d6a JD |
1945 | "addr 0x%02x\n", adap_id, address_list[i]); |
1946 | temp_client->addr = address_list[i]; | |
ccfbbd08 | 1947 | err = i2c_detect_address(temp_client, driver); |
51b54ba9 JD |
1948 | if (unlikely(err)) |
1949 | break; | |
4735c98f JD |
1950 | } |
1951 | ||
4735c98f JD |
1952 | kfree(temp_client); |
1953 | return err; | |
1954 | } | |
1955 | ||
d44f19d5 JD |
1956 | int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) |
1957 | { | |
1958 | return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1959 | I2C_SMBUS_QUICK, NULL) >= 0; | |
1960 | } | |
1961 | EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); | |
1962 | ||
12b5053a JD |
1963 | struct i2c_client * |
1964 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1965 | struct i2c_board_info *info, | |
9a94241a JD |
1966 | unsigned short const *addr_list, |
1967 | int (*probe)(struct i2c_adapter *, unsigned short addr)) | |
12b5053a JD |
1968 | { |
1969 | int i; | |
1970 | ||
8031d79b | 1971 | if (!probe) |
9a94241a | 1972 | probe = i2c_default_probe; |
12b5053a | 1973 | |
12b5053a JD |
1974 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1975 | /* Check address validity */ | |
656b8761 | 1976 | if (i2c_check_addr_validity(addr_list[i]) < 0) { |
12b5053a JD |
1977 | dev_warn(&adap->dev, "Invalid 7-bit address " |
1978 | "0x%02x\n", addr_list[i]); | |
1979 | continue; | |
1980 | } | |
1981 | ||
1982 | /* Check address availability */ | |
3b5f794b | 1983 | if (i2c_check_addr_busy(adap, addr_list[i])) { |
12b5053a JD |
1984 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1985 | "use, not probing\n", addr_list[i]); | |
1986 | continue; | |
1987 | } | |
1988 | ||
63e4e802 | 1989 | /* Test address responsiveness */ |
9a94241a | 1990 | if (probe(adap, addr_list[i])) |
63e4e802 | 1991 | break; |
12b5053a | 1992 | } |
12b5053a JD |
1993 | |
1994 | if (addr_list[i] == I2C_CLIENT_END) { | |
1995 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1996 | return NULL; | |
1997 | } | |
1998 | ||
1999 | info->addr = addr_list[i]; | |
2000 | return i2c_new_device(adap, info); | |
2001 | } | |
2002 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
2003 | ||
d735b34d | 2004 | struct i2c_adapter *i2c_get_adapter(int nr) |
1da177e4 | 2005 | { |
1da177e4 | 2006 | struct i2c_adapter *adapter; |
438d6c2c | 2007 | |
caada32a | 2008 | mutex_lock(&core_lock); |
d735b34d | 2009 | adapter = idr_find(&i2c_adapter_idr, nr); |
a0920e10 MH |
2010 | if (adapter && !try_module_get(adapter->owner)) |
2011 | adapter = NULL; | |
2012 | ||
caada32a | 2013 | mutex_unlock(&core_lock); |
a0920e10 | 2014 | return adapter; |
1da177e4 | 2015 | } |
c0564606 | 2016 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
2017 | |
2018 | void i2c_put_adapter(struct i2c_adapter *adap) | |
2019 | { | |
c66c4cc0 SH |
2020 | if (adap) |
2021 | module_put(adap->owner); | |
1da177e4 | 2022 | } |
c0564606 | 2023 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
2024 | |
2025 | /* The SMBus parts */ | |
2026 | ||
438d6c2c | 2027 | #define POLY (0x1070U << 3) |
09b8ce0a | 2028 | static u8 crc8(u16 data) |
1da177e4 LT |
2029 | { |
2030 | int i; | |
438d6c2c | 2031 | |
7225acf4 | 2032 | for (i = 0; i < 8; i++) { |
438d6c2c | 2033 | if (data & 0x8000) |
1da177e4 LT |
2034 | data = data ^ POLY; |
2035 | data = data << 1; | |
2036 | } | |
2037 | return (u8)(data >> 8); | |
2038 | } | |
2039 | ||
421ef47b JD |
2040 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
2041 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
2042 | { |
2043 | int i; | |
2044 | ||
7225acf4 | 2045 | for (i = 0; i < count; i++) |
421ef47b | 2046 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
2047 | return crc; |
2048 | } | |
2049 | ||
421ef47b JD |
2050 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
2051 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 2052 | { |
421ef47b JD |
2053 | /* The address will be sent first */ |
2054 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
2055 | pec = i2c_smbus_pec(pec, &addr, 1); | |
2056 | ||
2057 | /* The data buffer follows */ | |
2058 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
2059 | } |
2060 | ||
421ef47b JD |
2061 | /* Used for write only transactions */ |
2062 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 2063 | { |
421ef47b JD |
2064 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
2065 | msg->len++; | |
1da177e4 LT |
2066 | } |
2067 | ||
421ef47b JD |
2068 | /* Return <0 on CRC error |
2069 | If there was a write before this read (most cases) we need to take the | |
2070 | partial CRC from the write part into account. | |
2071 | Note that this function does modify the message (we need to decrease the | |
2072 | message length to hide the CRC byte from the caller). */ | |
2073 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 2074 | { |
421ef47b JD |
2075 | u8 rpec = msg->buf[--msg->len]; |
2076 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 2077 | |
1da177e4 LT |
2078 | if (rpec != cpec) { |
2079 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
2080 | rpec, cpec); | |
24a5bb7b | 2081 | return -EBADMSG; |
1da177e4 | 2082 | } |
438d6c2c | 2083 | return 0; |
1da177e4 LT |
2084 | } |
2085 | ||
a1cdedac DB |
2086 | /** |
2087 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
2088 | * @client: Handle to slave device | |
2089 | * | |
2090 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
2091 | * else the byte received from the device. | |
2092 | */ | |
0cc43a18 | 2093 | s32 i2c_smbus_read_byte(const struct i2c_client *client) |
1da177e4 LT |
2094 | { |
2095 | union i2c_smbus_data data; | |
24a5bb7b DB |
2096 | int status; |
2097 | ||
2098 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2099 | I2C_SMBUS_READ, 0, | |
2100 | I2C_SMBUS_BYTE, &data); | |
2101 | return (status < 0) ? status : data.byte; | |
1da177e4 | 2102 | } |
c0564606 | 2103 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 2104 | |
a1cdedac DB |
2105 | /** |
2106 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
2107 | * @client: Handle to slave device | |
2108 | * @value: Byte to be sent | |
2109 | * | |
2110 | * This executes the SMBus "send byte" protocol, returning negative errno | |
2111 | * else zero on success. | |
2112 | */ | |
0cc43a18 | 2113 | s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value) |
1da177e4 | 2114 | { |
7225acf4 | 2115 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
421ef47b | 2116 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 2117 | } |
c0564606 | 2118 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 2119 | |
a1cdedac DB |
2120 | /** |
2121 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
2122 | * @client: Handle to slave device | |
2123 | * @command: Byte interpreted by slave | |
2124 | * | |
2125 | * This executes the SMBus "read byte" protocol, returning negative errno | |
2126 | * else a data byte received from the device. | |
2127 | */ | |
0cc43a18 | 2128 | s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command) |
1da177e4 LT |
2129 | { |
2130 | union i2c_smbus_data data; | |
24a5bb7b DB |
2131 | int status; |
2132 | ||
2133 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2134 | I2C_SMBUS_READ, command, | |
2135 | I2C_SMBUS_BYTE_DATA, &data); | |
2136 | return (status < 0) ? status : data.byte; | |
1da177e4 | 2137 | } |
c0564606 | 2138 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 2139 | |
a1cdedac DB |
2140 | /** |
2141 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
2142 | * @client: Handle to slave device | |
2143 | * @command: Byte interpreted by slave | |
2144 | * @value: Byte being written | |
2145 | * | |
2146 | * This executes the SMBus "write byte" protocol, returning negative errno | |
2147 | * else zero on success. | |
2148 | */ | |
0cc43a18 JD |
2149 | s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command, |
2150 | u8 value) | |
1da177e4 LT |
2151 | { |
2152 | union i2c_smbus_data data; | |
2153 | data.byte = value; | |
7225acf4 FH |
2154 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2155 | I2C_SMBUS_WRITE, command, | |
2156 | I2C_SMBUS_BYTE_DATA, &data); | |
1da177e4 | 2157 | } |
c0564606 | 2158 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 2159 | |
a1cdedac DB |
2160 | /** |
2161 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
2162 | * @client: Handle to slave device | |
2163 | * @command: Byte interpreted by slave | |
2164 | * | |
2165 | * This executes the SMBus "read word" protocol, returning negative errno | |
2166 | * else a 16-bit unsigned "word" received from the device. | |
2167 | */ | |
0cc43a18 | 2168 | s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command) |
1da177e4 LT |
2169 | { |
2170 | union i2c_smbus_data data; | |
24a5bb7b DB |
2171 | int status; |
2172 | ||
2173 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2174 | I2C_SMBUS_READ, command, | |
2175 | I2C_SMBUS_WORD_DATA, &data); | |
2176 | return (status < 0) ? status : data.word; | |
1da177e4 | 2177 | } |
c0564606 | 2178 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 2179 | |
a1cdedac DB |
2180 | /** |
2181 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
2182 | * @client: Handle to slave device | |
2183 | * @command: Byte interpreted by slave | |
2184 | * @value: 16-bit "word" being written | |
2185 | * | |
2186 | * This executes the SMBus "write word" protocol, returning negative errno | |
2187 | * else zero on success. | |
2188 | */ | |
0cc43a18 JD |
2189 | s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command, |
2190 | u16 value) | |
1da177e4 LT |
2191 | { |
2192 | union i2c_smbus_data data; | |
2193 | data.word = value; | |
7225acf4 FH |
2194 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2195 | I2C_SMBUS_WRITE, command, | |
2196 | I2C_SMBUS_WORD_DATA, &data); | |
1da177e4 | 2197 | } |
c0564606 | 2198 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 2199 | |
a64ec07d | 2200 | /** |
a1cdedac | 2201 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 2202 | * @client: Handle to slave device |
a1cdedac | 2203 | * @command: Byte interpreted by slave |
a64ec07d DB |
2204 | * @values: Byte array into which data will be read; big enough to hold |
2205 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
2206 | * | |
a1cdedac DB |
2207 | * This executes the SMBus "block read" protocol, returning negative errno |
2208 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
2209 | * |
2210 | * Note that using this function requires that the client's adapter support | |
2211 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
2212 | * support this; its emulation through I2C messaging relies on a specific | |
2213 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
2214 | */ | |
0cc43a18 | 2215 | s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command, |
b86a1bc8 JD |
2216 | u8 *values) |
2217 | { | |
2218 | union i2c_smbus_data data; | |
24a5bb7b | 2219 | int status; |
b86a1bc8 | 2220 | |
24a5bb7b DB |
2221 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2222 | I2C_SMBUS_READ, command, | |
2223 | I2C_SMBUS_BLOCK_DATA, &data); | |
2224 | if (status) | |
2225 | return status; | |
b86a1bc8 JD |
2226 | |
2227 | memcpy(values, &data.block[1], data.block[0]); | |
2228 | return data.block[0]; | |
2229 | } | |
2230 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
2231 | ||
a1cdedac DB |
2232 | /** |
2233 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
2234 | * @client: Handle to slave device | |
2235 | * @command: Byte interpreted by slave | |
2236 | * @length: Size of data block; SMBus allows at most 32 bytes | |
2237 | * @values: Byte array which will be written. | |
2238 | * | |
2239 | * This executes the SMBus "block write" protocol, returning negative errno | |
2240 | * else zero on success. | |
2241 | */ | |
0cc43a18 | 2242 | s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command, |
46f5ed75 | 2243 | u8 length, const u8 *values) |
1da177e4 LT |
2244 | { |
2245 | union i2c_smbus_data data; | |
7656032b | 2246 | |
1da177e4 LT |
2247 | if (length > I2C_SMBUS_BLOCK_MAX) |
2248 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 2249 | data.block[0] = length; |
7656032b | 2250 | memcpy(&data.block[1], values, length); |
7225acf4 FH |
2251 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2252 | I2C_SMBUS_WRITE, command, | |
2253 | I2C_SMBUS_BLOCK_DATA, &data); | |
1da177e4 | 2254 | } |
c0564606 | 2255 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
2256 | |
2257 | /* Returns the number of read bytes */ | |
0cc43a18 | 2258 | s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command, |
4b2643d7 | 2259 | u8 length, u8 *values) |
1da177e4 LT |
2260 | { |
2261 | union i2c_smbus_data data; | |
24a5bb7b | 2262 | int status; |
7656032b | 2263 | |
4b2643d7 JD |
2264 | if (length > I2C_SMBUS_BLOCK_MAX) |
2265 | length = I2C_SMBUS_BLOCK_MAX; | |
2266 | data.block[0] = length; | |
24a5bb7b DB |
2267 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2268 | I2C_SMBUS_READ, command, | |
2269 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
2270 | if (status < 0) | |
2271 | return status; | |
7656032b JD |
2272 | |
2273 | memcpy(values, &data.block[1], data.block[0]); | |
2274 | return data.block[0]; | |
1da177e4 | 2275 | } |
c0564606 | 2276 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 2277 | |
0cc43a18 | 2278 | s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command, |
46f5ed75 | 2279 | u8 length, const u8 *values) |
21bbd691 JD |
2280 | { |
2281 | union i2c_smbus_data data; | |
2282 | ||
2283 | if (length > I2C_SMBUS_BLOCK_MAX) | |
2284 | length = I2C_SMBUS_BLOCK_MAX; | |
2285 | data.block[0] = length; | |
2286 | memcpy(data.block + 1, values, length); | |
2287 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2288 | I2C_SMBUS_WRITE, command, | |
2289 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
2290 | } | |
c0564606 | 2291 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 2292 | |
438d6c2c | 2293 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 2294 | No checking of parameters is done! */ |
7225acf4 FH |
2295 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, |
2296 | unsigned short flags, | |
2297 | char read_write, u8 command, int size, | |
2298 | union i2c_smbus_data *data) | |
1da177e4 LT |
2299 | { |
2300 | /* So we need to generate a series of msgs. In the case of writing, we | |
2301 | need to use only one message; when reading, we need two. We initialize | |
2302 | most things with sane defaults, to keep the code below somewhat | |
2303 | simpler. */ | |
5c50d188 HI |
2304 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
2305 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
7225acf4 | 2306 | int num = read_write == I2C_SMBUS_READ ? 2 : 1; |
1da177e4 | 2307 | int i; |
421ef47b | 2308 | u8 partial_pec = 0; |
24a5bb7b | 2309 | int status; |
230da094 S |
2310 | struct i2c_msg msg[2] = { |
2311 | { | |
2312 | .addr = addr, | |
2313 | .flags = flags, | |
2314 | .len = 1, | |
2315 | .buf = msgbuf0, | |
2316 | }, { | |
2317 | .addr = addr, | |
2318 | .flags = flags | I2C_M_RD, | |
2319 | .len = 0, | |
2320 | .buf = msgbuf1, | |
2321 | }, | |
2322 | }; | |
1da177e4 LT |
2323 | |
2324 | msgbuf0[0] = command; | |
7225acf4 | 2325 | switch (size) { |
1da177e4 LT |
2326 | case I2C_SMBUS_QUICK: |
2327 | msg[0].len = 0; | |
2328 | /* Special case: The read/write field is used as data */ | |
f29d2e02 RK |
2329 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
2330 | I2C_M_RD : 0); | |
1da177e4 LT |
2331 | num = 1; |
2332 | break; | |
2333 | case I2C_SMBUS_BYTE: | |
2334 | if (read_write == I2C_SMBUS_READ) { | |
2335 | /* Special case: only a read! */ | |
2336 | msg[0].flags = I2C_M_RD | flags; | |
2337 | num = 1; | |
2338 | } | |
2339 | break; | |
2340 | case I2C_SMBUS_BYTE_DATA: | |
2341 | if (read_write == I2C_SMBUS_READ) | |
2342 | msg[1].len = 1; | |
2343 | else { | |
2344 | msg[0].len = 2; | |
2345 | msgbuf0[1] = data->byte; | |
2346 | } | |
2347 | break; | |
2348 | case I2C_SMBUS_WORD_DATA: | |
2349 | if (read_write == I2C_SMBUS_READ) | |
2350 | msg[1].len = 2; | |
2351 | else { | |
7225acf4 | 2352 | msg[0].len = 3; |
1da177e4 | 2353 | msgbuf0[1] = data->word & 0xff; |
7eff82c8 | 2354 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
2355 | } |
2356 | break; | |
2357 | case I2C_SMBUS_PROC_CALL: | |
2358 | num = 2; /* Special case */ | |
2359 | read_write = I2C_SMBUS_READ; | |
2360 | msg[0].len = 3; | |
2361 | msg[1].len = 2; | |
2362 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 2363 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
2364 | break; |
2365 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 2366 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
2367 | msg[1].flags |= I2C_M_RECV_LEN; |
2368 | msg[1].len = 1; /* block length will be added by | |
2369 | the underlying bus driver */ | |
1da177e4 LT |
2370 | } else { |
2371 | msg[0].len = data->block[0] + 2; | |
2372 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
2373 | dev_err(&adapter->dev, |
2374 | "Invalid block write size %d\n", | |
2375 | data->block[0]); | |
2376 | return -EINVAL; | |
1da177e4 | 2377 | } |
5c50d188 | 2378 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
2379 | msgbuf0[i] = data->block[i-1]; |
2380 | } | |
2381 | break; | |
2382 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
2383 | num = 2; /* Another special case */ |
2384 | read_write = I2C_SMBUS_READ; | |
2385 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
2386 | dev_err(&adapter->dev, |
2387 | "Invalid block write size %d\n", | |
209d27c3 | 2388 | data->block[0]); |
24a5bb7b | 2389 | return -EINVAL; |
209d27c3 JD |
2390 | } |
2391 | msg[0].len = data->block[0] + 2; | |
2392 | for (i = 1; i < msg[0].len; i++) | |
2393 | msgbuf0[i] = data->block[i-1]; | |
2394 | msg[1].flags |= I2C_M_RECV_LEN; | |
2395 | msg[1].len = 1; /* block length will be added by | |
2396 | the underlying bus driver */ | |
2397 | break; | |
1da177e4 LT |
2398 | case I2C_SMBUS_I2C_BLOCK_DATA: |
2399 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 2400 | msg[1].len = data->block[0]; |
1da177e4 LT |
2401 | } else { |
2402 | msg[0].len = data->block[0] + 1; | |
30dac746 | 2403 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
2404 | dev_err(&adapter->dev, |
2405 | "Invalid block write size %d\n", | |
2406 | data->block[0]); | |
2407 | return -EINVAL; | |
1da177e4 LT |
2408 | } |
2409 | for (i = 1; i <= data->block[0]; i++) | |
2410 | msgbuf0[i] = data->block[i]; | |
2411 | } | |
2412 | break; | |
2413 | default: | |
24a5bb7b DB |
2414 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
2415 | return -EOPNOTSUPP; | |
1da177e4 LT |
2416 | } |
2417 | ||
421ef47b JD |
2418 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
2419 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
2420 | if (i) { | |
2421 | /* Compute PEC if first message is a write */ | |
2422 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 2423 | if (num == 1) /* Write only */ |
421ef47b JD |
2424 | i2c_smbus_add_pec(&msg[0]); |
2425 | else /* Write followed by read */ | |
2426 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
2427 | } | |
2428 | /* Ask for PEC if last message is a read */ | |
2429 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 2430 | msg[num-1].len++; |
421ef47b JD |
2431 | } |
2432 | ||
24a5bb7b DB |
2433 | status = i2c_transfer(adapter, msg, num); |
2434 | if (status < 0) | |
2435 | return status; | |
1da177e4 | 2436 | |
421ef47b JD |
2437 | /* Check PEC if last message is a read */ |
2438 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
2439 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
2440 | if (status < 0) | |
2441 | return status; | |
421ef47b JD |
2442 | } |
2443 | ||
1da177e4 | 2444 | if (read_write == I2C_SMBUS_READ) |
7225acf4 FH |
2445 | switch (size) { |
2446 | case I2C_SMBUS_BYTE: | |
2447 | data->byte = msgbuf0[0]; | |
2448 | break; | |
2449 | case I2C_SMBUS_BYTE_DATA: | |
2450 | data->byte = msgbuf1[0]; | |
2451 | break; | |
2452 | case I2C_SMBUS_WORD_DATA: | |
2453 | case I2C_SMBUS_PROC_CALL: | |
2454 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
2455 | break; | |
2456 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
2457 | for (i = 0; i < data->block[0]; i++) | |
2458 | data->block[i+1] = msgbuf1[i]; | |
2459 | break; | |
2460 | case I2C_SMBUS_BLOCK_DATA: | |
2461 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
2462 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
2463 | data->block[i] = msgbuf1[i]; | |
2464 | break; | |
1da177e4 LT |
2465 | } |
2466 | return 0; | |
2467 | } | |
2468 | ||
a1cdedac DB |
2469 | /** |
2470 | * i2c_smbus_xfer - execute SMBus protocol operations | |
2471 | * @adapter: Handle to I2C bus | |
2472 | * @addr: Address of SMBus slave on that bus | |
2473 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
2474 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
2475 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
2476 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
2477 | * @data: Data to be read or written | |
2478 | * | |
2479 | * This executes an SMBus protocol operation, and returns a negative | |
2480 | * errno code else zero on success. | |
2481 | */ | |
09b8ce0a | 2482 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
a1cdedac | 2483 | char read_write, u8 command, int protocol, |
09b8ce0a | 2484 | union i2c_smbus_data *data) |
1da177e4 | 2485 | { |
66b650f0 CW |
2486 | unsigned long orig_jiffies; |
2487 | int try; | |
1da177e4 | 2488 | s32 res; |
1da177e4 | 2489 | |
8a325997 DH |
2490 | /* If enabled, the following two tracepoints are conditional on |
2491 | * read_write and protocol. | |
2492 | */ | |
2493 | trace_smbus_write(adapter, addr, flags, read_write, | |
2494 | command, protocol, data); | |
2495 | trace_smbus_read(adapter, addr, flags, read_write, | |
2496 | command, protocol); | |
2497 | ||
d47726c5 | 2498 | flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB; |
1da177e4 LT |
2499 | |
2500 | if (adapter->algo->smbus_xfer) { | |
fe61e07e | 2501 | i2c_lock_adapter(adapter); |
66b650f0 CW |
2502 | |
2503 | /* Retry automatically on arbitration loss */ | |
2504 | orig_jiffies = jiffies; | |
2505 | for (res = 0, try = 0; try <= adapter->retries; try++) { | |
2506 | res = adapter->algo->smbus_xfer(adapter, addr, flags, | |
2507 | read_write, command, | |
2508 | protocol, data); | |
2509 | if (res != -EAGAIN) | |
2510 | break; | |
2511 | if (time_after(jiffies, | |
2512 | orig_jiffies + adapter->timeout)) | |
2513 | break; | |
2514 | } | |
fe61e07e | 2515 | i2c_unlock_adapter(adapter); |
1da177e4 | 2516 | |
72fc2c7f | 2517 | if (res != -EOPNOTSUPP || !adapter->algo->master_xfer) |
8a325997 | 2518 | goto trace; |
72fc2c7f LP |
2519 | /* |
2520 | * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't | |
2521 | * implement native support for the SMBus operation. | |
2522 | */ | |
2523 | } | |
2524 | ||
8a325997 DH |
2525 | res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, |
2526 | command, protocol, data); | |
2527 | ||
2528 | trace: | |
2529 | /* If enabled, the reply tracepoint is conditional on read_write. */ | |
2530 | trace_smbus_reply(adapter, addr, flags, read_write, | |
2531 | command, protocol, data); | |
2532 | trace_smbus_result(adapter, addr, flags, read_write, | |
2533 | command, protocol, res); | |
2534 | ||
2535 | return res; | |
1da177e4 | 2536 | } |
1da177e4 | 2537 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
2538 | |
2539 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
2540 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
2541 | MODULE_LICENSE("GPL"); |