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 | ||
e09b0d4e UH |
282 | status = dev_pm_domain_attach(&client->dev, true); |
283 | if (status != -EPROBE_DEFER) { | |
284 | status = driver->probe(client, i2c_match_id(driver->id_table, | |
285 | client)); | |
286 | if (status) | |
287 | dev_pm_domain_detach(&client->dev, true); | |
288 | } | |
72fa818e | 289 | |
50c3304a | 290 | return status; |
f37dd80a | 291 | } |
1da177e4 | 292 | |
f37dd80a DB |
293 | static int i2c_device_remove(struct device *dev) |
294 | { | |
51298d12 | 295 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 | 296 | struct i2c_driver *driver; |
72fa818e | 297 | int status = 0; |
a1d9e6e4 | 298 | |
51298d12 | 299 | if (!client || !dev->driver) |
a1d9e6e4 DB |
300 | return 0; |
301 | ||
302 | driver = to_i2c_driver(dev->driver); | |
303 | if (driver->remove) { | |
304 | dev_dbg(dev, "remove\n"); | |
305 | status = driver->remove(client); | |
a1d9e6e4 | 306 | } |
72fa818e | 307 | |
e09b0d4e | 308 | dev_pm_domain_detach(&client->dev, true); |
a1d9e6e4 | 309 | return status; |
1da177e4 LT |
310 | } |
311 | ||
f37dd80a | 312 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 313 | { |
51298d12 | 314 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
315 | struct i2c_driver *driver; |
316 | ||
51298d12 | 317 | if (!client || !dev->driver) |
f37dd80a DB |
318 | return; |
319 | driver = to_i2c_driver(dev->driver); | |
320 | if (driver->shutdown) | |
51298d12 | 321 | driver->shutdown(client); |
1da177e4 LT |
322 | } |
323 | ||
2f60ba70 RW |
324 | #ifdef CONFIG_PM_SLEEP |
325 | static int i2c_legacy_suspend(struct device *dev, pm_message_t mesg) | |
54067ee2 | 326 | { |
2f60ba70 RW |
327 | struct i2c_client *client = i2c_verify_client(dev); |
328 | struct i2c_driver *driver; | |
54067ee2 | 329 | |
2f60ba70 | 330 | if (!client || !dev->driver) |
54067ee2 | 331 | return 0; |
2f60ba70 RW |
332 | driver = to_i2c_driver(dev->driver); |
333 | if (!driver->suspend) | |
54067ee2 | 334 | return 0; |
2f60ba70 | 335 | return driver->suspend(client, mesg); |
54067ee2 | 336 | } |
337 | ||
2f60ba70 | 338 | static int i2c_legacy_resume(struct device *dev) |
54067ee2 | 339 | { |
2f60ba70 RW |
340 | struct i2c_client *client = i2c_verify_client(dev); |
341 | struct i2c_driver *driver; | |
54067ee2 | 342 | |
2f60ba70 | 343 | if (!client || !dev->driver) |
54067ee2 | 344 | return 0; |
2f60ba70 RW |
345 | driver = to_i2c_driver(dev->driver); |
346 | if (!driver->resume) | |
54067ee2 | 347 | return 0; |
2f60ba70 | 348 | return driver->resume(client); |
54067ee2 | 349 | } |
54067ee2 | 350 | |
2f60ba70 | 351 | static int i2c_device_pm_suspend(struct device *dev) |
6de468ae | 352 | { |
2f60ba70 | 353 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 354 | |
d529de29 MB |
355 | if (pm) |
356 | return pm_generic_suspend(dev); | |
357 | else | |
358 | return i2c_legacy_suspend(dev, PMSG_SUSPEND); | |
6de468ae MB |
359 | } |
360 | ||
2f60ba70 | 361 | static int i2c_device_pm_resume(struct device *dev) |
6de468ae | 362 | { |
2f60ba70 | 363 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 364 | |
2f60ba70 | 365 | if (pm) |
d529de29 | 366 | return pm_generic_resume(dev); |
2f60ba70 | 367 | else |
d529de29 | 368 | return i2c_legacy_resume(dev); |
6de468ae | 369 | } |
6de468ae | 370 | |
2f60ba70 | 371 | static int i2c_device_pm_freeze(struct device *dev) |
1da177e4 | 372 | { |
2f60ba70 | 373 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 374 | |
d529de29 MB |
375 | if (pm) |
376 | return pm_generic_freeze(dev); | |
377 | else | |
378 | return i2c_legacy_suspend(dev, PMSG_FREEZE); | |
1da177e4 LT |
379 | } |
380 | ||
2f60ba70 | 381 | static int i2c_device_pm_thaw(struct device *dev) |
1da177e4 | 382 | { |
2f60ba70 | 383 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 384 | |
d529de29 MB |
385 | if (pm) |
386 | return pm_generic_thaw(dev); | |
387 | else | |
388 | return i2c_legacy_resume(dev); | |
2f60ba70 RW |
389 | } |
390 | ||
391 | static int i2c_device_pm_poweroff(struct device *dev) | |
392 | { | |
393 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
394 | ||
d529de29 MB |
395 | if (pm) |
396 | return pm_generic_poweroff(dev); | |
397 | else | |
398 | return i2c_legacy_suspend(dev, PMSG_HIBERNATE); | |
2f60ba70 RW |
399 | } |
400 | ||
401 | static int i2c_device_pm_restore(struct device *dev) | |
402 | { | |
403 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
2f60ba70 RW |
404 | |
405 | if (pm) | |
d529de29 | 406 | return pm_generic_restore(dev); |
2f60ba70 | 407 | else |
d529de29 | 408 | return i2c_legacy_resume(dev); |
1da177e4 | 409 | } |
2f60ba70 RW |
410 | #else /* !CONFIG_PM_SLEEP */ |
411 | #define i2c_device_pm_suspend NULL | |
412 | #define i2c_device_pm_resume NULL | |
413 | #define i2c_device_pm_freeze NULL | |
414 | #define i2c_device_pm_thaw NULL | |
415 | #define i2c_device_pm_poweroff NULL | |
416 | #define i2c_device_pm_restore NULL | |
417 | #endif /* !CONFIG_PM_SLEEP */ | |
1da177e4 | 418 | |
9c1600ed DB |
419 | static void i2c_client_dev_release(struct device *dev) |
420 | { | |
421 | kfree(to_i2c_client(dev)); | |
422 | } | |
423 | ||
09b8ce0a | 424 | static ssize_t |
4f8cf824 | 425 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 426 | { |
4f8cf824 JD |
427 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
428 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 DB |
429 | } |
430 | ||
09b8ce0a ZX |
431 | static ssize_t |
432 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
433 | { |
434 | struct i2c_client *client = to_i2c_client(dev); | |
8c4ff6d0 ZR |
435 | int len; |
436 | ||
437 | len = acpi_device_modalias(dev, buf, PAGE_SIZE -1); | |
438 | if (len != -ENODEV) | |
439 | return len; | |
440 | ||
eb8a7908 | 441 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
442 | } |
443 | ||
4f8cf824 | 444 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
51298d12 JD |
445 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
446 | ||
447 | static struct attribute *i2c_dev_attrs[] = { | |
448 | &dev_attr_name.attr, | |
7b4fbc50 | 449 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
450 | &dev_attr_modalias.attr, |
451 | NULL | |
452 | }; | |
453 | ||
454 | static struct attribute_group i2c_dev_attr_group = { | |
455 | .attrs = i2c_dev_attrs, | |
456 | }; | |
457 | ||
458 | static const struct attribute_group *i2c_dev_attr_groups[] = { | |
459 | &i2c_dev_attr_group, | |
460 | NULL | |
7b4fbc50 DB |
461 | }; |
462 | ||
0b2c3688 | 463 | static const struct dev_pm_ops i2c_device_pm_ops = { |
54067ee2 | 464 | .suspend = i2c_device_pm_suspend, |
465 | .resume = i2c_device_pm_resume, | |
2f60ba70 RW |
466 | .freeze = i2c_device_pm_freeze, |
467 | .thaw = i2c_device_pm_thaw, | |
468 | .poweroff = i2c_device_pm_poweroff, | |
469 | .restore = i2c_device_pm_restore, | |
470 | SET_RUNTIME_PM_OPS( | |
471 | pm_generic_runtime_suspend, | |
472 | pm_generic_runtime_resume, | |
45f0a85c | 473 | NULL |
2f60ba70 | 474 | ) |
54067ee2 | 475 | }; |
476 | ||
e9ca9eb9 | 477 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
478 | .name = "i2c", |
479 | .match = i2c_device_match, | |
480 | .probe = i2c_device_probe, | |
481 | .remove = i2c_device_remove, | |
482 | .shutdown = i2c_device_shutdown, | |
54067ee2 | 483 | .pm = &i2c_device_pm_ops, |
b864c7d5 | 484 | }; |
e9ca9eb9 | 485 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 486 | |
51298d12 JD |
487 | static struct device_type i2c_client_type = { |
488 | .groups = i2c_dev_attr_groups, | |
489 | .uevent = i2c_device_uevent, | |
490 | .release = i2c_client_dev_release, | |
491 | }; | |
492 | ||
9b766b81 DB |
493 | |
494 | /** | |
495 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
496 | * @dev: device, probably from some driver model iterator | |
497 | * | |
498 | * When traversing the driver model tree, perhaps using driver model | |
499 | * iterators like @device_for_each_child(), you can't assume very much | |
500 | * about the nodes you find. Use this function to avoid oopses caused | |
501 | * by wrongly treating some non-I2C device as an i2c_client. | |
502 | */ | |
503 | struct i2c_client *i2c_verify_client(struct device *dev) | |
504 | { | |
51298d12 | 505 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
506 | ? to_i2c_client(dev) |
507 | : NULL; | |
508 | } | |
509 | EXPORT_SYMBOL(i2c_verify_client); | |
510 | ||
511 | ||
3a89db5f | 512 | /* This is a permissive address validity check, I2C address map constraints |
25985edc | 513 | * are purposely not enforced, except for the general call address. */ |
3a89db5f JD |
514 | static int i2c_check_client_addr_validity(const struct i2c_client *client) |
515 | { | |
516 | if (client->flags & I2C_CLIENT_TEN) { | |
517 | /* 10-bit address, all values are valid */ | |
518 | if (client->addr > 0x3ff) | |
519 | return -EINVAL; | |
520 | } else { | |
521 | /* 7-bit address, reject the general call address */ | |
522 | if (client->addr == 0x00 || client->addr > 0x7f) | |
523 | return -EINVAL; | |
524 | } | |
525 | return 0; | |
526 | } | |
527 | ||
656b8761 JD |
528 | /* And this is a strict address validity check, used when probing. If a |
529 | * device uses a reserved address, then it shouldn't be probed. 7-bit | |
530 | * addressing is assumed, 10-bit address devices are rare and should be | |
531 | * explicitly enumerated. */ | |
532 | static int i2c_check_addr_validity(unsigned short addr) | |
533 | { | |
534 | /* | |
535 | * Reserved addresses per I2C specification: | |
536 | * 0x00 General call address / START byte | |
537 | * 0x01 CBUS address | |
538 | * 0x02 Reserved for different bus format | |
539 | * 0x03 Reserved for future purposes | |
540 | * 0x04-0x07 Hs-mode master code | |
541 | * 0x78-0x7b 10-bit slave addressing | |
542 | * 0x7c-0x7f Reserved for future purposes | |
543 | */ | |
544 | if (addr < 0x08 || addr > 0x77) | |
545 | return -EINVAL; | |
546 | return 0; | |
547 | } | |
548 | ||
3b5f794b JD |
549 | static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
550 | { | |
551 | struct i2c_client *client = i2c_verify_client(dev); | |
552 | int addr = *(int *)addrp; | |
553 | ||
554 | if (client && client->addr == addr) | |
555 | return -EBUSY; | |
556 | return 0; | |
557 | } | |
558 | ||
0826374b ML |
559 | /* walk up mux tree */ |
560 | static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
561 | { | |
97cc4d49 | 562 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
563 | int result; |
564 | ||
565 | result = device_for_each_child(&adapter->dev, &addr, | |
566 | __i2c_check_addr_busy); | |
567 | ||
97cc4d49 JD |
568 | if (!result && parent) |
569 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
570 | |
571 | return result; | |
572 | } | |
573 | ||
574 | /* recurse down mux tree */ | |
575 | static int i2c_check_mux_children(struct device *dev, void *addrp) | |
576 | { | |
577 | int result; | |
578 | ||
579 | if (dev->type == &i2c_adapter_type) | |
580 | result = device_for_each_child(dev, addrp, | |
581 | i2c_check_mux_children); | |
582 | else | |
583 | result = __i2c_check_addr_busy(dev, addrp); | |
584 | ||
585 | return result; | |
586 | } | |
587 | ||
3b5f794b JD |
588 | static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) |
589 | { | |
97cc4d49 | 590 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
591 | int result = 0; |
592 | ||
97cc4d49 JD |
593 | if (parent) |
594 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
595 | |
596 | if (!result) | |
597 | result = device_for_each_child(&adapter->dev, &addr, | |
598 | i2c_check_mux_children); | |
599 | ||
600 | return result; | |
3b5f794b JD |
601 | } |
602 | ||
fe61e07e JD |
603 | /** |
604 | * i2c_lock_adapter - Get exclusive access to an I2C bus segment | |
605 | * @adapter: Target I2C bus segment | |
606 | */ | |
607 | void i2c_lock_adapter(struct i2c_adapter *adapter) | |
608 | { | |
97cc4d49 JD |
609 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
610 | ||
611 | if (parent) | |
612 | i2c_lock_adapter(parent); | |
0826374b ML |
613 | else |
614 | rt_mutex_lock(&adapter->bus_lock); | |
fe61e07e JD |
615 | } |
616 | EXPORT_SYMBOL_GPL(i2c_lock_adapter); | |
617 | ||
618 | /** | |
619 | * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment | |
620 | * @adapter: Target I2C bus segment | |
621 | */ | |
622 | static int i2c_trylock_adapter(struct i2c_adapter *adapter) | |
623 | { | |
97cc4d49 JD |
624 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
625 | ||
626 | if (parent) | |
627 | return i2c_trylock_adapter(parent); | |
0826374b ML |
628 | else |
629 | return rt_mutex_trylock(&adapter->bus_lock); | |
fe61e07e JD |
630 | } |
631 | ||
632 | /** | |
633 | * i2c_unlock_adapter - Release exclusive access to an I2C bus segment | |
634 | * @adapter: Target I2C bus segment | |
635 | */ | |
636 | void i2c_unlock_adapter(struct i2c_adapter *adapter) | |
637 | { | |
97cc4d49 JD |
638 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
639 | ||
640 | if (parent) | |
641 | i2c_unlock_adapter(parent); | |
0826374b ML |
642 | else |
643 | rt_mutex_unlock(&adapter->bus_lock); | |
fe61e07e JD |
644 | } |
645 | EXPORT_SYMBOL_GPL(i2c_unlock_adapter); | |
646 | ||
70762abb JN |
647 | static void i2c_dev_set_name(struct i2c_adapter *adap, |
648 | struct i2c_client *client) | |
649 | { | |
650 | struct acpi_device *adev = ACPI_COMPANION(&client->dev); | |
651 | ||
652 | if (adev) { | |
653 | dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); | |
654 | return; | |
655 | } | |
656 | ||
657 | /* For 10-bit clients, add an arbitrary offset to avoid collisions */ | |
658 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), | |
659 | client->addr | ((client->flags & I2C_CLIENT_TEN) | |
660 | ? 0xa000 : 0)); | |
661 | } | |
662 | ||
9c1600ed | 663 | /** |
f8a227e8 | 664 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
665 | * @adap: the adapter managing the device |
666 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 667 | * Context: can sleep |
9c1600ed | 668 | * |
f8a227e8 JD |
669 | * Create an i2c device. Binding is handled through driver model |
670 | * probe()/remove() methods. A driver may be bound to this device when we | |
671 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
672 | * load the driver module). This call is not appropriate for use by mainboard | |
673 | * initialization logic, which usually runs during an arch_initcall() long | |
674 | * before any i2c_adapter could exist. | |
9c1600ed DB |
675 | * |
676 | * This returns the new i2c client, which may be saved for later use with | |
677 | * i2c_unregister_device(); or NULL to indicate an error. | |
678 | */ | |
679 | struct i2c_client * | |
680 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
681 | { | |
682 | struct i2c_client *client; | |
683 | int status; | |
684 | ||
685 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
686 | if (!client) | |
687 | return NULL; | |
688 | ||
689 | client->adapter = adap; | |
690 | ||
691 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 692 | |
11f1f2af AV |
693 | if (info->archdata) |
694 | client->dev.archdata = *info->archdata; | |
695 | ||
ee35425c | 696 | client->flags = info->flags; |
9c1600ed DB |
697 | client->addr = info->addr; |
698 | client->irq = info->irq; | |
699 | ||
9c1600ed DB |
700 | strlcpy(client->name, info->type, sizeof(client->name)); |
701 | ||
3a89db5f JD |
702 | /* Check for address validity */ |
703 | status = i2c_check_client_addr_validity(client); | |
704 | if (status) { | |
705 | dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", | |
706 | client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); | |
707 | goto out_err_silent; | |
708 | } | |
709 | ||
f8a227e8 | 710 | /* Check for address business */ |
3b5f794b | 711 | status = i2c_check_addr_busy(adap, client->addr); |
f8a227e8 JD |
712 | if (status) |
713 | goto out_err; | |
714 | ||
715 | client->dev.parent = &client->adapter->dev; | |
716 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 717 | client->dev.type = &i2c_client_type; |
d12d42f7 | 718 | client->dev.of_node = info->of_node; |
7b199811 | 719 | ACPI_COMPANION_SET(&client->dev, info->acpi_node.companion); |
f8a227e8 | 720 | |
70762abb | 721 | i2c_dev_set_name(adap, client); |
f8a227e8 JD |
722 | status = device_register(&client->dev); |
723 | if (status) | |
724 | goto out_err; | |
725 | ||
f8a227e8 JD |
726 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
727 | client->name, dev_name(&client->dev)); | |
728 | ||
9c1600ed | 729 | return client; |
f8a227e8 JD |
730 | |
731 | out_err: | |
732 | dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " | |
733 | "(%d)\n", client->name, client->addr, status); | |
3a89db5f | 734 | out_err_silent: |
f8a227e8 JD |
735 | kfree(client); |
736 | return NULL; | |
9c1600ed DB |
737 | } |
738 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
739 | ||
740 | ||
741 | /** | |
742 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
743 | * @client: value returned from i2c_new_device() | |
d64f73be | 744 | * Context: can sleep |
9c1600ed DB |
745 | */ |
746 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 747 | { |
a1d9e6e4 DB |
748 | device_unregister(&client->dev); |
749 | } | |
9c1600ed | 750 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
751 | |
752 | ||
60b129d7 JD |
753 | static const struct i2c_device_id dummy_id[] = { |
754 | { "dummy", 0 }, | |
755 | { }, | |
756 | }; | |
757 | ||
d2653e92 JD |
758 | static int dummy_probe(struct i2c_client *client, |
759 | const struct i2c_device_id *id) | |
760 | { | |
761 | return 0; | |
762 | } | |
763 | ||
764 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
765 | { |
766 | return 0; | |
767 | } | |
768 | ||
769 | static struct i2c_driver dummy_driver = { | |
770 | .driver.name = "dummy", | |
d2653e92 JD |
771 | .probe = dummy_probe, |
772 | .remove = dummy_remove, | |
60b129d7 | 773 | .id_table = dummy_id, |
e9f1373b DB |
774 | }; |
775 | ||
776 | /** | |
777 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
778 | * @adapter: the adapter managing the device | |
779 | * @address: seven bit address to be used | |
e9f1373b DB |
780 | * Context: can sleep |
781 | * | |
782 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
783 | * with devices that consume multiple addresses. Examples of such chips | |
784 | * include various EEPROMS (like 24c04 and 24c08 models). | |
785 | * | |
786 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
787 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
788 | * And second, this prevents the specified address from being bound to a | |
789 | * different driver. | |
790 | * | |
791 | * This returns the new i2c client, which should be saved for later use with | |
792 | * i2c_unregister_device(); or NULL to indicate an error. | |
793 | */ | |
09b8ce0a | 794 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
795 | { |
796 | struct i2c_board_info info = { | |
60b129d7 | 797 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
798 | }; |
799 | ||
e9f1373b DB |
800 | return i2c_new_device(adapter, &info); |
801 | } | |
802 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
803 | ||
f37dd80a DB |
804 | /* ------------------------------------------------------------------------- */ |
805 | ||
16ffadfc DB |
806 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
807 | ||
83eaaed0 | 808 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 809 | { |
ef2c8321 | 810 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
811 | complete(&adap->dev_released); |
812 | } | |
813 | ||
390946b1 JD |
814 | /* |
815 | * This function is only needed for mutex_lock_nested, so it is never | |
816 | * called unless locking correctness checking is enabled. Thus we | |
817 | * make it inline to avoid a compiler warning. That's what gcc ends up | |
818 | * doing anyway. | |
819 | */ | |
820 | static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) | |
821 | { | |
822 | unsigned int depth = 0; | |
823 | ||
824 | while ((adapter = i2c_parent_is_i2c_adapter(adapter))) | |
825 | depth++; | |
826 | ||
827 | return depth; | |
828 | } | |
829 | ||
99cd8e25 JD |
830 | /* |
831 | * Let users instantiate I2C devices through sysfs. This can be used when | |
832 | * platform initialization code doesn't contain the proper data for | |
833 | * whatever reason. Also useful for drivers that do device detection and | |
834 | * detection fails, either because the device uses an unexpected address, | |
835 | * or this is a compatible device with different ID register values. | |
836 | * | |
837 | * Parameter checking may look overzealous, but we really don't want | |
838 | * the user to provide incorrect parameters. | |
839 | */ | |
840 | static ssize_t | |
841 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
842 | const char *buf, size_t count) | |
843 | { | |
844 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
845 | struct i2c_board_info info; | |
846 | struct i2c_client *client; | |
847 | char *blank, end; | |
848 | int res; | |
849 | ||
99cd8e25 JD |
850 | memset(&info, 0, sizeof(struct i2c_board_info)); |
851 | ||
852 | blank = strchr(buf, ' '); | |
853 | if (!blank) { | |
854 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
855 | return -EINVAL; | |
856 | } | |
857 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
858 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
859 | return -EINVAL; | |
860 | } | |
861 | memcpy(info.type, buf, blank - buf); | |
862 | ||
863 | /* Parse remaining parameters, reject extra parameters */ | |
864 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
865 | if (res < 1) { | |
866 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
867 | return -EINVAL; | |
868 | } | |
869 | if (res > 1 && end != '\n') { | |
870 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
871 | return -EINVAL; | |
872 | } | |
873 | ||
99cd8e25 JD |
874 | client = i2c_new_device(adap, &info); |
875 | if (!client) | |
3a89db5f | 876 | return -EINVAL; |
99cd8e25 JD |
877 | |
878 | /* Keep track of the added device */ | |
dafc50d1 | 879 | mutex_lock(&adap->userspace_clients_lock); |
6629dcff | 880 | list_add_tail(&client->detected, &adap->userspace_clients); |
dafc50d1 | 881 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
882 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
883 | info.type, info.addr); | |
884 | ||
885 | return count; | |
886 | } | |
887 | ||
888 | /* | |
889 | * And of course let the users delete the devices they instantiated, if | |
890 | * they got it wrong. This interface can only be used to delete devices | |
891 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
892 | * don't delete devices to which some kernel code still has references. | |
893 | * | |
894 | * Parameter checking may look overzealous, but we really don't want | |
895 | * the user to delete the wrong device. | |
896 | */ | |
897 | static ssize_t | |
898 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
899 | const char *buf, size_t count) | |
900 | { | |
901 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
902 | struct i2c_client *client, *next; | |
903 | unsigned short addr; | |
904 | char end; | |
905 | int res; | |
906 | ||
907 | /* Parse parameters, reject extra parameters */ | |
908 | res = sscanf(buf, "%hi%c", &addr, &end); | |
909 | if (res < 1) { | |
910 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
911 | return -EINVAL; | |
912 | } | |
913 | if (res > 1 && end != '\n') { | |
914 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
915 | return -EINVAL; | |
916 | } | |
917 | ||
918 | /* Make sure the device was added through sysfs */ | |
919 | res = -ENOENT; | |
390946b1 JD |
920 | mutex_lock_nested(&adap->userspace_clients_lock, |
921 | i2c_adapter_depth(adap)); | |
6629dcff JD |
922 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
923 | detected) { | |
924 | if (client->addr == addr) { | |
99cd8e25 JD |
925 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
926 | "delete_device", client->name, client->addr); | |
927 | ||
928 | list_del(&client->detected); | |
929 | i2c_unregister_device(client); | |
930 | res = count; | |
931 | break; | |
932 | } | |
933 | } | |
dafc50d1 | 934 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
935 | |
936 | if (res < 0) | |
937 | dev_err(dev, "%s: Can't find device in list\n", | |
938 | "delete_device"); | |
939 | return res; | |
940 | } | |
941 | ||
4f8cf824 | 942 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
e9b526fe AS |
943 | static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, |
944 | i2c_sysfs_delete_device); | |
4f8cf824 JD |
945 | |
946 | static struct attribute *i2c_adapter_attrs[] = { | |
947 | &dev_attr_name.attr, | |
948 | &dev_attr_new_device.attr, | |
949 | &dev_attr_delete_device.attr, | |
950 | NULL | |
951 | }; | |
952 | ||
953 | static struct attribute_group i2c_adapter_attr_group = { | |
954 | .attrs = i2c_adapter_attrs, | |
955 | }; | |
956 | ||
957 | static const struct attribute_group *i2c_adapter_attr_groups[] = { | |
958 | &i2c_adapter_attr_group, | |
959 | NULL | |
16ffadfc | 960 | }; |
b119dc3f | 961 | |
0826374b | 962 | struct device_type i2c_adapter_type = { |
4f8cf824 JD |
963 | .groups = i2c_adapter_attr_groups, |
964 | .release = i2c_adapter_dev_release, | |
1da177e4 | 965 | }; |
0826374b | 966 | EXPORT_SYMBOL_GPL(i2c_adapter_type); |
1da177e4 | 967 | |
643dd09e SW |
968 | /** |
969 | * i2c_verify_adapter - return parameter as i2c_adapter or NULL | |
970 | * @dev: device, probably from some driver model iterator | |
971 | * | |
972 | * When traversing the driver model tree, perhaps using driver model | |
973 | * iterators like @device_for_each_child(), you can't assume very much | |
974 | * about the nodes you find. Use this function to avoid oopses caused | |
975 | * by wrongly treating some non-I2C device as an i2c_adapter. | |
976 | */ | |
977 | struct i2c_adapter *i2c_verify_adapter(struct device *dev) | |
978 | { | |
979 | return (dev->type == &i2c_adapter_type) | |
980 | ? to_i2c_adapter(dev) | |
981 | : NULL; | |
982 | } | |
983 | EXPORT_SYMBOL(i2c_verify_adapter); | |
984 | ||
2bb5095a JD |
985 | #ifdef CONFIG_I2C_COMPAT |
986 | static struct class_compat *i2c_adapter_compat_class; | |
987 | #endif | |
988 | ||
9c1600ed DB |
989 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
990 | { | |
991 | struct i2c_devinfo *devinfo; | |
992 | ||
f18c41da | 993 | down_read(&__i2c_board_lock); |
9c1600ed DB |
994 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
995 | if (devinfo->busnum == adapter->nr | |
996 | && !i2c_new_device(adapter, | |
997 | &devinfo->board_info)) | |
09b8ce0a ZX |
998 | dev_err(&adapter->dev, |
999 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
1000 | devinfo->board_info.addr); |
1001 | } | |
f18c41da | 1002 | up_read(&__i2c_board_lock); |
9c1600ed DB |
1003 | } |
1004 | ||
687b81d0 WS |
1005 | /* OF support code */ |
1006 | ||
1007 | #if IS_ENABLED(CONFIG_OF) | |
1008 | static void of_i2c_register_devices(struct i2c_adapter *adap) | |
1009 | { | |
1010 | void *result; | |
1011 | struct device_node *node; | |
1012 | ||
1013 | /* Only register child devices if the adapter has a node pointer set */ | |
1014 | if (!adap->dev.of_node) | |
1015 | return; | |
1016 | ||
1017 | dev_dbg(&adap->dev, "of_i2c: walking child nodes\n"); | |
1018 | ||
1019 | for_each_available_child_of_node(adap->dev.of_node, node) { | |
1020 | struct i2c_board_info info = {}; | |
1021 | struct dev_archdata dev_ad = {}; | |
1022 | const __be32 *addr; | |
1023 | int len; | |
1024 | ||
1025 | dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name); | |
1026 | ||
1027 | if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) { | |
1028 | dev_err(&adap->dev, "of_i2c: modalias failure on %s\n", | |
1029 | node->full_name); | |
1030 | continue; | |
1031 | } | |
1032 | ||
1033 | addr = of_get_property(node, "reg", &len); | |
1034 | if (!addr || (len < sizeof(int))) { | |
1035 | dev_err(&adap->dev, "of_i2c: invalid reg on %s\n", | |
1036 | node->full_name); | |
1037 | continue; | |
1038 | } | |
1039 | ||
1040 | info.addr = be32_to_cpup(addr); | |
1041 | if (info.addr > (1 << 10) - 1) { | |
1042 | dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n", | |
1043 | info.addr, node->full_name); | |
1044 | continue; | |
1045 | } | |
1046 | ||
1047 | info.irq = irq_of_parse_and_map(node, 0); | |
1048 | info.of_node = of_node_get(node); | |
1049 | info.archdata = &dev_ad; | |
1050 | ||
1051 | if (of_get_property(node, "wakeup-source", NULL)) | |
1052 | info.flags |= I2C_CLIENT_WAKE; | |
1053 | ||
1054 | request_module("%s%s", I2C_MODULE_PREFIX, info.type); | |
1055 | ||
1056 | result = i2c_new_device(adap, &info); | |
1057 | if (result == NULL) { | |
1058 | dev_err(&adap->dev, "of_i2c: Failure registering %s\n", | |
1059 | node->full_name); | |
1060 | of_node_put(node); | |
1061 | irq_dispose_mapping(info.irq); | |
1062 | continue; | |
1063 | } | |
1064 | } | |
1065 | } | |
1066 | ||
1067 | static int of_dev_node_match(struct device *dev, void *data) | |
1068 | { | |
1069 | return dev->of_node == data; | |
1070 | } | |
1071 | ||
1072 | /* must call put_device() when done with returned i2c_client device */ | |
1073 | struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) | |
1074 | { | |
1075 | struct device *dev; | |
1076 | ||
1077 | dev = bus_find_device(&i2c_bus_type, NULL, node, | |
1078 | of_dev_node_match); | |
1079 | if (!dev) | |
1080 | return NULL; | |
1081 | ||
1082 | return i2c_verify_client(dev); | |
1083 | } | |
1084 | EXPORT_SYMBOL(of_find_i2c_device_by_node); | |
1085 | ||
1086 | /* must call put_device() when done with returned i2c_adapter device */ | |
1087 | struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) | |
1088 | { | |
1089 | struct device *dev; | |
1090 | ||
1091 | dev = bus_find_device(&i2c_bus_type, NULL, node, | |
1092 | of_dev_node_match); | |
1093 | if (!dev) | |
1094 | return NULL; | |
1095 | ||
1096 | return i2c_verify_adapter(dev); | |
1097 | } | |
1098 | EXPORT_SYMBOL(of_find_i2c_adapter_by_node); | |
1099 | #else | |
1100 | static void of_i2c_register_devices(struct i2c_adapter *adap) { } | |
1101 | #endif /* CONFIG_OF */ | |
1102 | ||
69b0089a JD |
1103 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
1104 | struct i2c_adapter *adap) | |
026526f5 | 1105 | { |
4735c98f JD |
1106 | /* Detect supported devices on that bus, and instantiate them */ |
1107 | i2c_detect(adap, driver); | |
1108 | ||
1109 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 | 1110 | if (driver->attach_adapter) { |
a920ff41 JD |
1111 | dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n", |
1112 | driver->driver.name); | |
fe6fc258 JD |
1113 | dev_warn(&adap->dev, "Please use another way to instantiate " |
1114 | "your i2c_client\n"); | |
026526f5 JD |
1115 | /* We ignore the return code; if it fails, too bad */ |
1116 | driver->attach_adapter(adap); | |
1117 | } | |
1118 | return 0; | |
1119 | } | |
1120 | ||
69b0089a JD |
1121 | static int __process_new_adapter(struct device_driver *d, void *data) |
1122 | { | |
1123 | return i2c_do_add_adapter(to_i2c_driver(d), data); | |
1124 | } | |
1125 | ||
6e13e641 | 1126 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 1127 | { |
d6703281 | 1128 | int res = 0; |
1da177e4 | 1129 | |
1d0b19c9 | 1130 | /* Can't register until after driver model init */ |
35fc37f8 JD |
1131 | if (unlikely(WARN_ON(!i2c_bus_type.p))) { |
1132 | res = -EAGAIN; | |
1133 | goto out_list; | |
1134 | } | |
1d0b19c9 | 1135 | |
2236baa7 JD |
1136 | /* Sanity checks */ |
1137 | if (unlikely(adap->name[0] == '\0')) { | |
1138 | pr_err("i2c-core: Attempt to register an adapter with " | |
1139 | "no name!\n"); | |
1140 | return -EINVAL; | |
1141 | } | |
1142 | if (unlikely(!adap->algo)) { | |
1143 | pr_err("i2c-core: Attempt to register adapter '%s' with " | |
1144 | "no algo!\n", adap->name); | |
1145 | return -EINVAL; | |
1146 | } | |
1147 | ||
194684e5 | 1148 | rt_mutex_init(&adap->bus_lock); |
dafc50d1 | 1149 | mutex_init(&adap->userspace_clients_lock); |
6629dcff | 1150 | INIT_LIST_HEAD(&adap->userspace_clients); |
1da177e4 | 1151 | |
8fcfef6e JD |
1152 | /* Set default timeout to 1 second if not already set */ |
1153 | if (adap->timeout == 0) | |
1154 | adap->timeout = HZ; | |
1155 | ||
27d9c183 | 1156 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
1157 | adap->dev.bus = &i2c_bus_type; |
1158 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 JD |
1159 | res = device_register(&adap->dev); |
1160 | if (res) | |
1161 | goto out_list; | |
1da177e4 | 1162 | |
b6d7b3d1 JD |
1163 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
1164 | ||
2bb5095a JD |
1165 | #ifdef CONFIG_I2C_COMPAT |
1166 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
1167 | adap->dev.parent); | |
1168 | if (res) | |
1169 | dev_warn(&adap->dev, | |
1170 | "Failed to create compatibility class link\n"); | |
1171 | #endif | |
1172 | ||
5f9296ba VK |
1173 | /* bus recovery specific initialization */ |
1174 | if (adap->bus_recovery_info) { | |
1175 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
1176 | ||
1177 | if (!bri->recover_bus) { | |
1178 | dev_err(&adap->dev, "No recover_bus() found, not using recovery\n"); | |
1179 | adap->bus_recovery_info = NULL; | |
1180 | goto exit_recovery; | |
1181 | } | |
1182 | ||
1183 | /* Generic GPIO recovery */ | |
1184 | if (bri->recover_bus == i2c_generic_gpio_recovery) { | |
1185 | if (!gpio_is_valid(bri->scl_gpio)) { | |
1186 | dev_err(&adap->dev, "Invalid SCL gpio, not using recovery\n"); | |
1187 | adap->bus_recovery_info = NULL; | |
1188 | goto exit_recovery; | |
1189 | } | |
1190 | ||
1191 | if (gpio_is_valid(bri->sda_gpio)) | |
1192 | bri->get_sda = get_sda_gpio_value; | |
1193 | else | |
1194 | bri->get_sda = NULL; | |
1195 | ||
1196 | bri->get_scl = get_scl_gpio_value; | |
1197 | bri->set_scl = set_scl_gpio_value; | |
1198 | } else if (!bri->set_scl || !bri->get_scl) { | |
1199 | /* Generic SCL recovery */ | |
1200 | dev_err(&adap->dev, "No {get|set}_gpio() found, not using recovery\n"); | |
1201 | adap->bus_recovery_info = NULL; | |
1202 | } | |
1203 | } | |
1204 | ||
1205 | exit_recovery: | |
729d6dd5 | 1206 | /* create pre-declared device nodes */ |
687b81d0 | 1207 | of_i2c_register_devices(adap); |
55e71edb | 1208 | acpi_i2c_register_devices(adap); |
5d98e61d | 1209 | acpi_i2c_install_space_handler(adap); |
687b81d0 | 1210 | |
6e13e641 DB |
1211 | if (adap->nr < __i2c_first_dynamic_bus_num) |
1212 | i2c_scan_static_board_info(adap); | |
1213 | ||
4735c98f | 1214 | /* Notify drivers */ |
35fc37f8 | 1215 | mutex_lock(&core_lock); |
d6703281 | 1216 | bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); |
caada32a | 1217 | mutex_unlock(&core_lock); |
35fc37f8 JD |
1218 | |
1219 | return 0; | |
b119c6c9 | 1220 | |
b119c6c9 | 1221 | out_list: |
35fc37f8 | 1222 | mutex_lock(&core_lock); |
b119c6c9 | 1223 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
1224 | mutex_unlock(&core_lock); |
1225 | return res; | |
1da177e4 LT |
1226 | } |
1227 | ||
ee5c2744 DA |
1228 | /** |
1229 | * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 | |
1230 | * @adap: the adapter to register (with adap->nr initialized) | |
1231 | * Context: can sleep | |
1232 | * | |
1233 | * See i2c_add_numbered_adapter() for details. | |
1234 | */ | |
1235 | static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1236 | { | |
1237 | int id; | |
1238 | ||
1239 | mutex_lock(&core_lock); | |
1240 | id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, | |
1241 | GFP_KERNEL); | |
1242 | mutex_unlock(&core_lock); | |
1243 | if (id < 0) | |
1244 | return id == -ENOSPC ? -EBUSY : id; | |
1245 | ||
1246 | return i2c_register_adapter(adap); | |
1247 | } | |
1248 | ||
6e13e641 DB |
1249 | /** |
1250 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
1251 | * @adapter: the adapter to add | |
d64f73be | 1252 | * Context: can sleep |
6e13e641 DB |
1253 | * |
1254 | * This routine is used to declare an I2C adapter when its bus number | |
ee5c2744 DA |
1255 | * doesn't matter or when its bus number is specified by an dt alias. |
1256 | * Examples of bases when the bus number doesn't matter: I2C adapters | |
1257 | * dynamically added by USB links or PCI plugin cards. | |
6e13e641 DB |
1258 | * |
1259 | * When this returns zero, a new bus number was allocated and stored | |
1260 | * in adap->nr, and the specified adapter became available for clients. | |
1261 | * Otherwise, a negative errno value is returned. | |
1262 | */ | |
1263 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
1264 | { | |
ee5c2744 | 1265 | struct device *dev = &adapter->dev; |
4ae42b0f | 1266 | int id; |
6e13e641 | 1267 | |
ee5c2744 DA |
1268 | if (dev->of_node) { |
1269 | id = of_alias_get_id(dev->of_node, "i2c"); | |
1270 | if (id >= 0) { | |
1271 | adapter->nr = id; | |
1272 | return __i2c_add_numbered_adapter(adapter); | |
1273 | } | |
1274 | } | |
1275 | ||
caada32a | 1276 | mutex_lock(&core_lock); |
4ae42b0f TH |
1277 | id = idr_alloc(&i2c_adapter_idr, adapter, |
1278 | __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); | |
caada32a | 1279 | mutex_unlock(&core_lock); |
4ae42b0f TH |
1280 | if (id < 0) |
1281 | return id; | |
6e13e641 DB |
1282 | |
1283 | adapter->nr = id; | |
4ae42b0f | 1284 | |
6e13e641 DB |
1285 | return i2c_register_adapter(adapter); |
1286 | } | |
1287 | EXPORT_SYMBOL(i2c_add_adapter); | |
1288 | ||
1289 | /** | |
1290 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
1291 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 1292 | * Context: can sleep |
6e13e641 DB |
1293 | * |
1294 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
1295 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
1296 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
1297 | * is used to properly configure I2C devices. |
1298 | * | |
488bf314 GL |
1299 | * If the requested bus number is set to -1, then this function will behave |
1300 | * identically to i2c_add_adapter, and will dynamically assign a bus number. | |
1301 | * | |
6e13e641 DB |
1302 | * If no devices have pre-been declared for this bus, then be sure to |
1303 | * register the adapter before any dynamically allocated ones. Otherwise | |
1304 | * the required bus ID may not be available. | |
1305 | * | |
1306 | * When this returns zero, the specified adapter became available for | |
1307 | * clients using the bus number provided in adap->nr. Also, the table | |
1308 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
1309 | * and the appropriate driver model device nodes are created. Otherwise, a | |
1310 | * negative errno value is returned. | |
1311 | */ | |
1312 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1313 | { | |
488bf314 GL |
1314 | if (adap->nr == -1) /* -1 means dynamically assign bus id */ |
1315 | return i2c_add_adapter(adap); | |
6e13e641 | 1316 | |
ee5c2744 | 1317 | return __i2c_add_numbered_adapter(adap); |
6e13e641 DB |
1318 | } |
1319 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
1320 | ||
19baba4c | 1321 | static void i2c_do_del_adapter(struct i2c_driver *driver, |
69b0089a | 1322 | struct i2c_adapter *adapter) |
026526f5 | 1323 | { |
4735c98f | 1324 | struct i2c_client *client, *_n; |
026526f5 | 1325 | |
acec211c JD |
1326 | /* Remove the devices we created ourselves as the result of hardware |
1327 | * probing (using a driver's detect method) */ | |
4735c98f JD |
1328 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
1329 | if (client->adapter == adapter) { | |
1330 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
1331 | client->name, client->addr); | |
1332 | list_del(&client->detected); | |
1333 | i2c_unregister_device(client); | |
1334 | } | |
1335 | } | |
026526f5 JD |
1336 | } |
1337 | ||
e549c2b5 | 1338 | static int __unregister_client(struct device *dev, void *dummy) |
5219bf88 JD |
1339 | { |
1340 | struct i2c_client *client = i2c_verify_client(dev); | |
1341 | if (client && strcmp(client->name, "dummy")) | |
1342 | i2c_unregister_device(client); | |
1343 | return 0; | |
1344 | } | |
1345 | ||
1346 | static int __unregister_dummy(struct device *dev, void *dummy) | |
e549c2b5 JD |
1347 | { |
1348 | struct i2c_client *client = i2c_verify_client(dev); | |
1349 | if (client) | |
1350 | i2c_unregister_device(client); | |
1351 | return 0; | |
1352 | } | |
1353 | ||
69b0089a JD |
1354 | static int __process_removed_adapter(struct device_driver *d, void *data) |
1355 | { | |
19baba4c LPC |
1356 | i2c_do_del_adapter(to_i2c_driver(d), data); |
1357 | return 0; | |
69b0089a JD |
1358 | } |
1359 | ||
d64f73be DB |
1360 | /** |
1361 | * i2c_del_adapter - unregister I2C adapter | |
1362 | * @adap: the adapter being unregistered | |
1363 | * Context: can sleep | |
1364 | * | |
1365 | * This unregisters an I2C adapter which was previously registered | |
1366 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
1367 | */ | |
71546300 | 1368 | void i2c_del_adapter(struct i2c_adapter *adap) |
1da177e4 | 1369 | { |
35fc37f8 | 1370 | struct i2c_adapter *found; |
bbd2d9c9 | 1371 | struct i2c_client *client, *next; |
1da177e4 LT |
1372 | |
1373 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
1374 | mutex_lock(&core_lock); |
1375 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
1376 | mutex_unlock(&core_lock); | |
1377 | if (found != adap) { | |
b6d7b3d1 JD |
1378 | pr_debug("i2c-core: attempting to delete unregistered " |
1379 | "adapter [%s]\n", adap->name); | |
71546300 | 1380 | return; |
1da177e4 LT |
1381 | } |
1382 | ||
5d98e61d | 1383 | acpi_i2c_remove_space_handler(adap); |
026526f5 | 1384 | /* Tell drivers about this removal */ |
35fc37f8 | 1385 | mutex_lock(&core_lock); |
19baba4c | 1386 | bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 1387 | __process_removed_adapter); |
35fc37f8 | 1388 | mutex_unlock(&core_lock); |
1da177e4 | 1389 | |
bbd2d9c9 | 1390 | /* Remove devices instantiated from sysfs */ |
390946b1 JD |
1391 | mutex_lock_nested(&adap->userspace_clients_lock, |
1392 | i2c_adapter_depth(adap)); | |
6629dcff JD |
1393 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1394 | detected) { | |
1395 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, | |
1396 | client->addr); | |
1397 | list_del(&client->detected); | |
1398 | i2c_unregister_device(client); | |
bbd2d9c9 | 1399 | } |
dafc50d1 | 1400 | mutex_unlock(&adap->userspace_clients_lock); |
bbd2d9c9 | 1401 | |
e549c2b5 | 1402 | /* Detach any active clients. This can't fail, thus we do not |
5219bf88 JD |
1403 | * check the returned value. This is a two-pass process, because |
1404 | * we can't remove the dummy devices during the first pass: they | |
1405 | * could have been instantiated by real devices wishing to clean | |
1406 | * them up properly, so we give them a chance to do that first. */ | |
19baba4c LPC |
1407 | device_for_each_child(&adap->dev, NULL, __unregister_client); |
1408 | device_for_each_child(&adap->dev, NULL, __unregister_dummy); | |
1da177e4 | 1409 | |
2bb5095a JD |
1410 | #ifdef CONFIG_I2C_COMPAT |
1411 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
1412 | adap->dev.parent); | |
1413 | #endif | |
1414 | ||
c5567521 TLSC |
1415 | /* device name is gone after device_unregister */ |
1416 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); | |
1417 | ||
1da177e4 LT |
1418 | /* clean up the sysfs representation */ |
1419 | init_completion(&adap->dev_released); | |
1da177e4 | 1420 | device_unregister(&adap->dev); |
1da177e4 LT |
1421 | |
1422 | /* wait for sysfs to drop all references */ | |
1423 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 1424 | |
6e13e641 | 1425 | /* free bus id */ |
35fc37f8 | 1426 | mutex_lock(&core_lock); |
1da177e4 | 1427 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 1428 | mutex_unlock(&core_lock); |
1da177e4 | 1429 | |
bd4bc3db JD |
1430 | /* Clear the device structure in case this adapter is ever going to be |
1431 | added again */ | |
1432 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
1da177e4 | 1433 | } |
c0564606 | 1434 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 | 1435 | |
7b4fbc50 DB |
1436 | /* ------------------------------------------------------------------------- */ |
1437 | ||
7ae31482 JD |
1438 | int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) |
1439 | { | |
1440 | int res; | |
1441 | ||
1442 | mutex_lock(&core_lock); | |
1443 | res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); | |
1444 | mutex_unlock(&core_lock); | |
1445 | ||
1446 | return res; | |
1447 | } | |
1448 | EXPORT_SYMBOL_GPL(i2c_for_each_dev); | |
1449 | ||
69b0089a | 1450 | static int __process_new_driver(struct device *dev, void *data) |
7f101a97 | 1451 | { |
4f8cf824 JD |
1452 | if (dev->type != &i2c_adapter_type) |
1453 | return 0; | |
69b0089a | 1454 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
7f101a97 DY |
1455 | } |
1456 | ||
7b4fbc50 DB |
1457 | /* |
1458 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 1459 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
1460 | */ |
1461 | ||
de59cf9e | 1462 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 1463 | { |
7eebcb7c | 1464 | int res; |
1da177e4 | 1465 | |
1d0b19c9 DB |
1466 | /* Can't register until after driver model init */ |
1467 | if (unlikely(WARN_ON(!i2c_bus_type.p))) | |
1468 | return -EAGAIN; | |
1469 | ||
1da177e4 | 1470 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 1471 | driver->driver.owner = owner; |
1da177e4 | 1472 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 1473 | |
729d6dd5 | 1474 | /* When registration returns, the driver core |
6e13e641 DB |
1475 | * will have called probe() for all matching-but-unbound devices. |
1476 | */ | |
1da177e4 LT |
1477 | res = driver_register(&driver->driver); |
1478 | if (res) | |
7eebcb7c | 1479 | return res; |
438d6c2c | 1480 | |
f4e8db31 MB |
1481 | /* Drivers should switch to dev_pm_ops instead. */ |
1482 | if (driver->suspend) | |
1483 | pr_warn("i2c-core: driver [%s] using legacy suspend method\n", | |
1484 | driver->driver.name); | |
1485 | if (driver->resume) | |
1486 | pr_warn("i2c-core: driver [%s] using legacy resume method\n", | |
1487 | driver->driver.name); | |
1488 | ||
35d8b2e6 | 1489 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 1490 | |
4735c98f JD |
1491 | INIT_LIST_HEAD(&driver->clients); |
1492 | /* Walk the adapters that are already present */ | |
7ae31482 | 1493 | i2c_for_each_dev(driver, __process_new_driver); |
35fc37f8 | 1494 | |
7f101a97 DY |
1495 | return 0; |
1496 | } | |
1497 | EXPORT_SYMBOL(i2c_register_driver); | |
1498 | ||
69b0089a | 1499 | static int __process_removed_driver(struct device *dev, void *data) |
7f101a97 | 1500 | { |
19baba4c LPC |
1501 | if (dev->type == &i2c_adapter_type) |
1502 | i2c_do_del_adapter(data, to_i2c_adapter(dev)); | |
1503 | return 0; | |
1da177e4 LT |
1504 | } |
1505 | ||
a1d9e6e4 DB |
1506 | /** |
1507 | * i2c_del_driver - unregister I2C driver | |
1508 | * @driver: the driver being unregistered | |
d64f73be | 1509 | * Context: can sleep |
a1d9e6e4 | 1510 | */ |
b3e82096 | 1511 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 1512 | { |
7ae31482 | 1513 | i2c_for_each_dev(driver, __process_removed_driver); |
1da177e4 LT |
1514 | |
1515 | driver_unregister(&driver->driver); | |
35d8b2e6 | 1516 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 1517 | } |
c0564606 | 1518 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 1519 | |
7b4fbc50 DB |
1520 | /* ------------------------------------------------------------------------- */ |
1521 | ||
e48d3319 JD |
1522 | /** |
1523 | * i2c_use_client - increments the reference count of the i2c client structure | |
1524 | * @client: the client being referenced | |
1525 | * | |
1526 | * Each live reference to a client should be refcounted. The driver model does | |
1527 | * that automatically as part of driver binding, so that most drivers don't | |
1528 | * need to do this explicitly: they hold a reference until they're unbound | |
1529 | * from the device. | |
1530 | * | |
1531 | * A pointer to the client with the incremented reference counter is returned. | |
1532 | */ | |
1533 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 1534 | { |
6ea438ec DB |
1535 | if (client && get_device(&client->dev)) |
1536 | return client; | |
1537 | return NULL; | |
1da177e4 | 1538 | } |
c0564606 | 1539 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 1540 | |
e48d3319 JD |
1541 | /** |
1542 | * i2c_release_client - release a use of the i2c client structure | |
1543 | * @client: the client being no longer referenced | |
1544 | * | |
1545 | * Must be called when a user of a client is finished with it. | |
1546 | */ | |
1547 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 1548 | { |
6ea438ec DB |
1549 | if (client) |
1550 | put_device(&client->dev); | |
1da177e4 | 1551 | } |
c0564606 | 1552 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 1553 | |
9b766b81 DB |
1554 | struct i2c_cmd_arg { |
1555 | unsigned cmd; | |
1556 | void *arg; | |
1557 | }; | |
1558 | ||
1559 | static int i2c_cmd(struct device *dev, void *_arg) | |
1560 | { | |
1561 | struct i2c_client *client = i2c_verify_client(dev); | |
1562 | struct i2c_cmd_arg *arg = _arg; | |
0acc2b32 LPC |
1563 | struct i2c_driver *driver; |
1564 | ||
1565 | if (!client || !client->dev.driver) | |
1566 | return 0; | |
9b766b81 | 1567 | |
0acc2b32 LPC |
1568 | driver = to_i2c_driver(client->dev.driver); |
1569 | if (driver->command) | |
1570 | driver->command(client, arg->cmd, arg->arg); | |
9b766b81 DB |
1571 | return 0; |
1572 | } | |
1573 | ||
1da177e4 LT |
1574 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
1575 | { | |
9b766b81 | 1576 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 1577 | |
9b766b81 DB |
1578 | cmd_arg.cmd = cmd; |
1579 | cmd_arg.arg = arg; | |
1580 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 1581 | } |
c0564606 | 1582 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
1583 | |
1584 | static int __init i2c_init(void) | |
1585 | { | |
1586 | int retval; | |
1587 | ||
1588 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
1589 | if (retval) |
1590 | return retval; | |
2bb5095a JD |
1591 | #ifdef CONFIG_I2C_COMPAT |
1592 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
1593 | if (!i2c_adapter_compat_class) { | |
1594 | retval = -ENOMEM; | |
1595 | goto bus_err; | |
1596 | } | |
1597 | #endif | |
e9f1373b DB |
1598 | retval = i2c_add_driver(&dummy_driver); |
1599 | if (retval) | |
2bb5095a | 1600 | goto class_err; |
e9f1373b DB |
1601 | return 0; |
1602 | ||
2bb5095a JD |
1603 | class_err: |
1604 | #ifdef CONFIG_I2C_COMPAT | |
1605 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 1606 | bus_err: |
2bb5095a | 1607 | #endif |
e9f1373b DB |
1608 | bus_unregister(&i2c_bus_type); |
1609 | return retval; | |
1da177e4 LT |
1610 | } |
1611 | ||
1612 | static void __exit i2c_exit(void) | |
1613 | { | |
e9f1373b | 1614 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
1615 | #ifdef CONFIG_I2C_COMPAT |
1616 | class_compat_unregister(i2c_adapter_compat_class); | |
1617 | #endif | |
1da177e4 | 1618 | bus_unregister(&i2c_bus_type); |
d9a83d62 | 1619 | tracepoint_synchronize_unregister(); |
1da177e4 LT |
1620 | } |
1621 | ||
a10f9e7c DB |
1622 | /* We must initialize early, because some subsystems register i2c drivers |
1623 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1624 | */ | |
1625 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1626 | module_exit(i2c_exit); |
1627 | ||
1628 | /* ---------------------------------------------------- | |
1629 | * the functional interface to the i2c busses. | |
1630 | * ---------------------------------------------------- | |
1631 | */ | |
1632 | ||
b37d2a3a JD |
1633 | /** |
1634 | * __i2c_transfer - unlocked flavor of i2c_transfer | |
1635 | * @adap: Handle to I2C bus | |
1636 | * @msgs: One or more messages to execute before STOP is issued to | |
1637 | * terminate the operation; each message begins with a START. | |
1638 | * @num: Number of messages to be executed. | |
1639 | * | |
1640 | * Returns negative errno, else the number of messages executed. | |
1641 | * | |
1642 | * Adapter lock must be held when calling this function. No debug logging | |
1643 | * takes place. adap->algo->master_xfer existence isn't checked. | |
1644 | */ | |
1645 | int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
1646 | { | |
1647 | unsigned long orig_jiffies; | |
1648 | int ret, try; | |
1649 | ||
d9a83d62 DH |
1650 | /* i2c_trace_msg gets enabled when tracepoint i2c_transfer gets |
1651 | * enabled. This is an efficient way of keeping the for-loop from | |
1652 | * being executed when not needed. | |
1653 | */ | |
1654 | if (static_key_false(&i2c_trace_msg)) { | |
1655 | int i; | |
1656 | for (i = 0; i < num; i++) | |
1657 | if (msgs[i].flags & I2C_M_RD) | |
1658 | trace_i2c_read(adap, &msgs[i], i); | |
1659 | else | |
1660 | trace_i2c_write(adap, &msgs[i], i); | |
1661 | } | |
1662 | ||
b37d2a3a JD |
1663 | /* Retry automatically on arbitration loss */ |
1664 | orig_jiffies = jiffies; | |
1665 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
1666 | ret = adap->algo->master_xfer(adap, msgs, num); | |
1667 | if (ret != -EAGAIN) | |
1668 | break; | |
1669 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
1670 | break; | |
1671 | } | |
1672 | ||
d9a83d62 DH |
1673 | if (static_key_false(&i2c_trace_msg)) { |
1674 | int i; | |
1675 | for (i = 0; i < ret; i++) | |
1676 | if (msgs[i].flags & I2C_M_RD) | |
1677 | trace_i2c_reply(adap, &msgs[i], i); | |
1678 | trace_i2c_result(adap, i, ret); | |
1679 | } | |
1680 | ||
b37d2a3a JD |
1681 | return ret; |
1682 | } | |
1683 | EXPORT_SYMBOL(__i2c_transfer); | |
1684 | ||
a1cdedac DB |
1685 | /** |
1686 | * i2c_transfer - execute a single or combined I2C message | |
1687 | * @adap: Handle to I2C bus | |
1688 | * @msgs: One or more messages to execute before STOP is issued to | |
1689 | * terminate the operation; each message begins with a START. | |
1690 | * @num: Number of messages to be executed. | |
1691 | * | |
1692 | * Returns negative errno, else the number of messages executed. | |
1693 | * | |
1694 | * Note that there is no requirement that each message be sent to | |
1695 | * the same slave address, although that is the most common model. | |
1696 | */ | |
09b8ce0a | 1697 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 1698 | { |
b37d2a3a | 1699 | int ret; |
1da177e4 | 1700 | |
a1cdedac DB |
1701 | /* REVISIT the fault reporting model here is weak: |
1702 | * | |
1703 | * - When we get an error after receiving N bytes from a slave, | |
1704 | * there is no way to report "N". | |
1705 | * | |
1706 | * - When we get a NAK after transmitting N bytes to a slave, | |
1707 | * there is no way to report "N" ... or to let the master | |
1708 | * continue executing the rest of this combined message, if | |
1709 | * that's the appropriate response. | |
1710 | * | |
1711 | * - When for example "num" is two and we successfully complete | |
1712 | * the first message but get an error part way through the | |
1713 | * second, it's unclear whether that should be reported as | |
1714 | * one (discarding status on the second message) or errno | |
1715 | * (discarding status on the first one). | |
1716 | */ | |
1717 | ||
1da177e4 LT |
1718 | if (adap->algo->master_xfer) { |
1719 | #ifdef DEBUG | |
1720 | for (ret = 0; ret < num; ret++) { | |
1721 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
1722 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
1723 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
1724 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
1725 | } |
1726 | #endif | |
1727 | ||
cea443a8 | 1728 | if (in_atomic() || irqs_disabled()) { |
fe61e07e | 1729 | ret = i2c_trylock_adapter(adap); |
cea443a8 MR |
1730 | if (!ret) |
1731 | /* I2C activity is ongoing. */ | |
1732 | return -EAGAIN; | |
1733 | } else { | |
fe61e07e | 1734 | i2c_lock_adapter(adap); |
cea443a8 MR |
1735 | } |
1736 | ||
b37d2a3a | 1737 | ret = __i2c_transfer(adap, msgs, num); |
fe61e07e | 1738 | i2c_unlock_adapter(adap); |
1da177e4 LT |
1739 | |
1740 | return ret; | |
1741 | } else { | |
1742 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1743 | return -EOPNOTSUPP; |
1da177e4 LT |
1744 | } |
1745 | } | |
c0564606 | 1746 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1747 | |
a1cdedac DB |
1748 | /** |
1749 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1750 | * @client: Handle to slave device | |
1751 | * @buf: Data that will be written to the slave | |
0c43ea54 | 1752 | * @count: How many bytes to write, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1753 | * |
1754 | * Returns negative errno, or else the number of bytes written. | |
1755 | */ | |
0cc43a18 | 1756 | int i2c_master_send(const struct i2c_client *client, const char *buf, int count) |
1da177e4 LT |
1757 | { |
1758 | int ret; | |
7225acf4 | 1759 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1760 | struct i2c_msg msg; |
1761 | ||
815f55f2 JD |
1762 | msg.addr = client->addr; |
1763 | msg.flags = client->flags & I2C_M_TEN; | |
1764 | msg.len = count; | |
1765 | msg.buf = (char *)buf; | |
438d6c2c | 1766 | |
815f55f2 | 1767 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1768 | |
834aa6f3 WS |
1769 | /* |
1770 | * If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1771 | * transmitted, else error code. | |
1772 | */ | |
815f55f2 | 1773 | return (ret == 1) ? count : ret; |
1da177e4 | 1774 | } |
c0564606 | 1775 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1776 | |
a1cdedac DB |
1777 | /** |
1778 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1779 | * @client: Handle to slave device | |
1780 | * @buf: Where to store data read from slave | |
0c43ea54 | 1781 | * @count: How many bytes to read, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1782 | * |
1783 | * Returns negative errno, or else the number of bytes read. | |
1784 | */ | |
0cc43a18 | 1785 | int i2c_master_recv(const struct i2c_client *client, char *buf, int count) |
1da177e4 | 1786 | { |
7225acf4 | 1787 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1788 | struct i2c_msg msg; |
1789 | int ret; | |
815f55f2 JD |
1790 | |
1791 | msg.addr = client->addr; | |
1792 | msg.flags = client->flags & I2C_M_TEN; | |
1793 | msg.flags |= I2C_M_RD; | |
1794 | msg.len = count; | |
1795 | msg.buf = buf; | |
1796 | ||
1797 | ret = i2c_transfer(adap, &msg, 1); | |
1798 | ||
834aa6f3 WS |
1799 | /* |
1800 | * If everything went ok (i.e. 1 msg received), return #bytes received, | |
1801 | * else error code. | |
1802 | */ | |
815f55f2 | 1803 | return (ret == 1) ? count : ret; |
1da177e4 | 1804 | } |
c0564606 | 1805 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1806 | |
1da177e4 LT |
1807 | /* ---------------------------------------------------- |
1808 | * the i2c address scanning function | |
1809 | * Will not work for 10-bit addresses! | |
1810 | * ---------------------------------------------------- | |
1811 | */ | |
1da177e4 | 1812 | |
63e4e802 JD |
1813 | /* |
1814 | * Legacy default probe function, mostly relevant for SMBus. The default | |
1815 | * probe method is a quick write, but it is known to corrupt the 24RF08 | |
1816 | * EEPROMs due to a state machine bug, and could also irreversibly | |
1817 | * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, | |
1818 | * we use a short byte read instead. Also, some bus drivers don't implement | |
1819 | * quick write, so we fallback to a byte read in that case too. | |
1820 | * On x86, there is another special case for FSC hardware monitoring chips, | |
1821 | * which want regular byte reads (address 0x73.) Fortunately, these are the | |
1822 | * only known chips using this I2C address on PC hardware. | |
1823 | * Returns 1 if probe succeeded, 0 if not. | |
1824 | */ | |
1825 | static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) | |
1826 | { | |
1827 | int err; | |
1828 | union i2c_smbus_data dummy; | |
1829 | ||
1830 | #ifdef CONFIG_X86 | |
1831 | if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) | |
1832 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) | |
1833 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1834 | I2C_SMBUS_BYTE_DATA, &dummy); | |
1835 | else | |
1836 | #endif | |
8031d79b JD |
1837 | if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) |
1838 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) | |
63e4e802 JD |
1839 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, |
1840 | I2C_SMBUS_QUICK, NULL); | |
8031d79b JD |
1841 | else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) |
1842 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1843 | I2C_SMBUS_BYTE, &dummy); | |
1844 | else { | |
d63a9e85 AL |
1845 | dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", |
1846 | addr); | |
8031d79b JD |
1847 | err = -EOPNOTSUPP; |
1848 | } | |
63e4e802 JD |
1849 | |
1850 | return err >= 0; | |
1851 | } | |
1852 | ||
ccfbbd08 | 1853 | static int i2c_detect_address(struct i2c_client *temp_client, |
4735c98f JD |
1854 | struct i2c_driver *driver) |
1855 | { | |
1856 | struct i2c_board_info info; | |
1857 | struct i2c_adapter *adapter = temp_client->adapter; | |
1858 | int addr = temp_client->addr; | |
1859 | int err; | |
1860 | ||
1861 | /* Make sure the address is valid */ | |
656b8761 JD |
1862 | err = i2c_check_addr_validity(addr); |
1863 | if (err) { | |
4735c98f JD |
1864 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
1865 | addr); | |
656b8761 | 1866 | return err; |
4735c98f JD |
1867 | } |
1868 | ||
1869 | /* Skip if already in use */ | |
3b5f794b | 1870 | if (i2c_check_addr_busy(adapter, addr)) |
4735c98f JD |
1871 | return 0; |
1872 | ||
ccfbbd08 | 1873 | /* Make sure there is something at this address */ |
63e4e802 JD |
1874 | if (!i2c_default_probe(adapter, addr)) |
1875 | return 0; | |
4735c98f JD |
1876 | |
1877 | /* Finally call the custom detection function */ | |
1878 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
1879 | info.addr = addr; | |
310ec792 | 1880 | err = driver->detect(temp_client, &info); |
4735c98f JD |
1881 | if (err) { |
1882 | /* -ENODEV is returned if the detection fails. We catch it | |
1883 | here as this isn't an error. */ | |
1884 | return err == -ENODEV ? 0 : err; | |
1885 | } | |
1886 | ||
1887 | /* Consistency check */ | |
1888 | if (info.type[0] == '\0') { | |
1889 | dev_err(&adapter->dev, "%s detection function provided " | |
1890 | "no name for 0x%x\n", driver->driver.name, | |
1891 | addr); | |
1892 | } else { | |
1893 | struct i2c_client *client; | |
1894 | ||
1895 | /* Detection succeeded, instantiate the device */ | |
0c176170 WS |
1896 | if (adapter->class & I2C_CLASS_DEPRECATED) |
1897 | dev_warn(&adapter->dev, | |
1898 | "This adapter will soon drop class based instantiation of devices. " | |
1899 | "Please make sure client 0x%02x gets instantiated by other means. " | |
1900 | "Check 'Documentation/i2c/instantiating-devices' for details.\n", | |
1901 | info.addr); | |
1902 | ||
4735c98f JD |
1903 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", |
1904 | info.type, info.addr); | |
1905 | client = i2c_new_device(adapter, &info); | |
1906 | if (client) | |
1907 | list_add_tail(&client->detected, &driver->clients); | |
1908 | else | |
1909 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
1910 | info.type, info.addr); | |
1911 | } | |
1912 | return 0; | |
1913 | } | |
1914 | ||
1915 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
1916 | { | |
c3813d6a | 1917 | const unsigned short *address_list; |
4735c98f JD |
1918 | struct i2c_client *temp_client; |
1919 | int i, err = 0; | |
1920 | int adap_id = i2c_adapter_id(adapter); | |
1921 | ||
c3813d6a JD |
1922 | address_list = driver->address_list; |
1923 | if (!driver->detect || !address_list) | |
4735c98f JD |
1924 | return 0; |
1925 | ||
45552272 WS |
1926 | /* Warn that the adapter lost class based instantiation */ |
1927 | if (adapter->class == I2C_CLASS_DEPRECATED) { | |
1928 | dev_dbg(&adapter->dev, | |
1929 | "This adapter dropped support for I2C classes and " | |
1930 | "won't auto-detect %s devices anymore. If you need it, check " | |
1931 | "'Documentation/i2c/instantiating-devices' for alternatives.\n", | |
1932 | driver->driver.name); | |
1933 | return 0; | |
1934 | } | |
1935 | ||
51b54ba9 JD |
1936 | /* Stop here if the classes do not match */ |
1937 | if (!(adapter->class & driver->class)) | |
1938 | return 0; | |
1939 | ||
4735c98f JD |
1940 | /* Set up a temporary client to help detect callback */ |
1941 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
1942 | if (!temp_client) | |
1943 | return -ENOMEM; | |
1944 | temp_client->adapter = adapter; | |
1945 | ||
c3813d6a | 1946 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
4735c98f | 1947 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
c3813d6a JD |
1948 | "addr 0x%02x\n", adap_id, address_list[i]); |
1949 | temp_client->addr = address_list[i]; | |
ccfbbd08 | 1950 | err = i2c_detect_address(temp_client, driver); |
51b54ba9 JD |
1951 | if (unlikely(err)) |
1952 | break; | |
4735c98f JD |
1953 | } |
1954 | ||
4735c98f JD |
1955 | kfree(temp_client); |
1956 | return err; | |
1957 | } | |
1958 | ||
d44f19d5 JD |
1959 | int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) |
1960 | { | |
1961 | return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1962 | I2C_SMBUS_QUICK, NULL) >= 0; | |
1963 | } | |
1964 | EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); | |
1965 | ||
12b5053a JD |
1966 | struct i2c_client * |
1967 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1968 | struct i2c_board_info *info, | |
9a94241a JD |
1969 | unsigned short const *addr_list, |
1970 | int (*probe)(struct i2c_adapter *, unsigned short addr)) | |
12b5053a JD |
1971 | { |
1972 | int i; | |
1973 | ||
8031d79b | 1974 | if (!probe) |
9a94241a | 1975 | probe = i2c_default_probe; |
12b5053a | 1976 | |
12b5053a JD |
1977 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1978 | /* Check address validity */ | |
656b8761 | 1979 | if (i2c_check_addr_validity(addr_list[i]) < 0) { |
12b5053a JD |
1980 | dev_warn(&adap->dev, "Invalid 7-bit address " |
1981 | "0x%02x\n", addr_list[i]); | |
1982 | continue; | |
1983 | } | |
1984 | ||
1985 | /* Check address availability */ | |
3b5f794b | 1986 | if (i2c_check_addr_busy(adap, addr_list[i])) { |
12b5053a JD |
1987 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1988 | "use, not probing\n", addr_list[i]); | |
1989 | continue; | |
1990 | } | |
1991 | ||
63e4e802 | 1992 | /* Test address responsiveness */ |
9a94241a | 1993 | if (probe(adap, addr_list[i])) |
63e4e802 | 1994 | break; |
12b5053a | 1995 | } |
12b5053a JD |
1996 | |
1997 | if (addr_list[i] == I2C_CLIENT_END) { | |
1998 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1999 | return NULL; | |
2000 | } | |
2001 | ||
2002 | info->addr = addr_list[i]; | |
2003 | return i2c_new_device(adap, info); | |
2004 | } | |
2005 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
2006 | ||
d735b34d | 2007 | struct i2c_adapter *i2c_get_adapter(int nr) |
1da177e4 | 2008 | { |
1da177e4 | 2009 | struct i2c_adapter *adapter; |
438d6c2c | 2010 | |
caada32a | 2011 | mutex_lock(&core_lock); |
d735b34d | 2012 | adapter = idr_find(&i2c_adapter_idr, nr); |
a0920e10 MH |
2013 | if (adapter && !try_module_get(adapter->owner)) |
2014 | adapter = NULL; | |
2015 | ||
caada32a | 2016 | mutex_unlock(&core_lock); |
a0920e10 | 2017 | return adapter; |
1da177e4 | 2018 | } |
c0564606 | 2019 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
2020 | |
2021 | void i2c_put_adapter(struct i2c_adapter *adap) | |
2022 | { | |
c66c4cc0 SH |
2023 | if (adap) |
2024 | module_put(adap->owner); | |
1da177e4 | 2025 | } |
c0564606 | 2026 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
2027 | |
2028 | /* The SMBus parts */ | |
2029 | ||
438d6c2c | 2030 | #define POLY (0x1070U << 3) |
09b8ce0a | 2031 | static u8 crc8(u16 data) |
1da177e4 LT |
2032 | { |
2033 | int i; | |
438d6c2c | 2034 | |
7225acf4 | 2035 | for (i = 0; i < 8; i++) { |
438d6c2c | 2036 | if (data & 0x8000) |
1da177e4 LT |
2037 | data = data ^ POLY; |
2038 | data = data << 1; | |
2039 | } | |
2040 | return (u8)(data >> 8); | |
2041 | } | |
2042 | ||
421ef47b JD |
2043 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
2044 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
2045 | { |
2046 | int i; | |
2047 | ||
7225acf4 | 2048 | for (i = 0; i < count; i++) |
421ef47b | 2049 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
2050 | return crc; |
2051 | } | |
2052 | ||
421ef47b JD |
2053 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
2054 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 2055 | { |
421ef47b JD |
2056 | /* The address will be sent first */ |
2057 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
2058 | pec = i2c_smbus_pec(pec, &addr, 1); | |
2059 | ||
2060 | /* The data buffer follows */ | |
2061 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
2062 | } |
2063 | ||
421ef47b JD |
2064 | /* Used for write only transactions */ |
2065 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 2066 | { |
421ef47b JD |
2067 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
2068 | msg->len++; | |
1da177e4 LT |
2069 | } |
2070 | ||
421ef47b JD |
2071 | /* Return <0 on CRC error |
2072 | If there was a write before this read (most cases) we need to take the | |
2073 | partial CRC from the write part into account. | |
2074 | Note that this function does modify the message (we need to decrease the | |
2075 | message length to hide the CRC byte from the caller). */ | |
2076 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 2077 | { |
421ef47b JD |
2078 | u8 rpec = msg->buf[--msg->len]; |
2079 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 2080 | |
1da177e4 LT |
2081 | if (rpec != cpec) { |
2082 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
2083 | rpec, cpec); | |
24a5bb7b | 2084 | return -EBADMSG; |
1da177e4 | 2085 | } |
438d6c2c | 2086 | return 0; |
1da177e4 LT |
2087 | } |
2088 | ||
a1cdedac DB |
2089 | /** |
2090 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
2091 | * @client: Handle to slave device | |
2092 | * | |
2093 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
2094 | * else the byte received from the device. | |
2095 | */ | |
0cc43a18 | 2096 | s32 i2c_smbus_read_byte(const struct i2c_client *client) |
1da177e4 LT |
2097 | { |
2098 | union i2c_smbus_data data; | |
24a5bb7b DB |
2099 | int status; |
2100 | ||
2101 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2102 | I2C_SMBUS_READ, 0, | |
2103 | I2C_SMBUS_BYTE, &data); | |
2104 | return (status < 0) ? status : data.byte; | |
1da177e4 | 2105 | } |
c0564606 | 2106 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 2107 | |
a1cdedac DB |
2108 | /** |
2109 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
2110 | * @client: Handle to slave device | |
2111 | * @value: Byte to be sent | |
2112 | * | |
2113 | * This executes the SMBus "send byte" protocol, returning negative errno | |
2114 | * else zero on success. | |
2115 | */ | |
0cc43a18 | 2116 | s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value) |
1da177e4 | 2117 | { |
7225acf4 | 2118 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
421ef47b | 2119 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 2120 | } |
c0564606 | 2121 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 2122 | |
a1cdedac DB |
2123 | /** |
2124 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
2125 | * @client: Handle to slave device | |
2126 | * @command: Byte interpreted by slave | |
2127 | * | |
2128 | * This executes the SMBus "read byte" protocol, returning negative errno | |
2129 | * else a data byte received from the device. | |
2130 | */ | |
0cc43a18 | 2131 | s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command) |
1da177e4 LT |
2132 | { |
2133 | union i2c_smbus_data data; | |
24a5bb7b DB |
2134 | int status; |
2135 | ||
2136 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2137 | I2C_SMBUS_READ, command, | |
2138 | I2C_SMBUS_BYTE_DATA, &data); | |
2139 | return (status < 0) ? status : data.byte; | |
1da177e4 | 2140 | } |
c0564606 | 2141 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 2142 | |
a1cdedac DB |
2143 | /** |
2144 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
2145 | * @client: Handle to slave device | |
2146 | * @command: Byte interpreted by slave | |
2147 | * @value: Byte being written | |
2148 | * | |
2149 | * This executes the SMBus "write byte" protocol, returning negative errno | |
2150 | * else zero on success. | |
2151 | */ | |
0cc43a18 JD |
2152 | s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command, |
2153 | u8 value) | |
1da177e4 LT |
2154 | { |
2155 | union i2c_smbus_data data; | |
2156 | data.byte = value; | |
7225acf4 FH |
2157 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2158 | I2C_SMBUS_WRITE, command, | |
2159 | I2C_SMBUS_BYTE_DATA, &data); | |
1da177e4 | 2160 | } |
c0564606 | 2161 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 2162 | |
a1cdedac DB |
2163 | /** |
2164 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
2165 | * @client: Handle to slave device | |
2166 | * @command: Byte interpreted by slave | |
2167 | * | |
2168 | * This executes the SMBus "read word" protocol, returning negative errno | |
2169 | * else a 16-bit unsigned "word" received from the device. | |
2170 | */ | |
0cc43a18 | 2171 | s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command) |
1da177e4 LT |
2172 | { |
2173 | union i2c_smbus_data data; | |
24a5bb7b DB |
2174 | int status; |
2175 | ||
2176 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2177 | I2C_SMBUS_READ, command, | |
2178 | I2C_SMBUS_WORD_DATA, &data); | |
2179 | return (status < 0) ? status : data.word; | |
1da177e4 | 2180 | } |
c0564606 | 2181 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 2182 | |
a1cdedac DB |
2183 | /** |
2184 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
2185 | * @client: Handle to slave device | |
2186 | * @command: Byte interpreted by slave | |
2187 | * @value: 16-bit "word" being written | |
2188 | * | |
2189 | * This executes the SMBus "write word" protocol, returning negative errno | |
2190 | * else zero on success. | |
2191 | */ | |
0cc43a18 JD |
2192 | s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command, |
2193 | u16 value) | |
1da177e4 LT |
2194 | { |
2195 | union i2c_smbus_data data; | |
2196 | data.word = value; | |
7225acf4 FH |
2197 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2198 | I2C_SMBUS_WRITE, command, | |
2199 | I2C_SMBUS_WORD_DATA, &data); | |
1da177e4 | 2200 | } |
c0564606 | 2201 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 2202 | |
a64ec07d | 2203 | /** |
a1cdedac | 2204 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 2205 | * @client: Handle to slave device |
a1cdedac | 2206 | * @command: Byte interpreted by slave |
a64ec07d DB |
2207 | * @values: Byte array into which data will be read; big enough to hold |
2208 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
2209 | * | |
a1cdedac DB |
2210 | * This executes the SMBus "block read" protocol, returning negative errno |
2211 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
2212 | * |
2213 | * Note that using this function requires that the client's adapter support | |
2214 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
2215 | * support this; its emulation through I2C messaging relies on a specific | |
2216 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
2217 | */ | |
0cc43a18 | 2218 | s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command, |
b86a1bc8 JD |
2219 | u8 *values) |
2220 | { | |
2221 | union i2c_smbus_data data; | |
24a5bb7b | 2222 | int status; |
b86a1bc8 | 2223 | |
24a5bb7b DB |
2224 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2225 | I2C_SMBUS_READ, command, | |
2226 | I2C_SMBUS_BLOCK_DATA, &data); | |
2227 | if (status) | |
2228 | return status; | |
b86a1bc8 JD |
2229 | |
2230 | memcpy(values, &data.block[1], data.block[0]); | |
2231 | return data.block[0]; | |
2232 | } | |
2233 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
2234 | ||
a1cdedac DB |
2235 | /** |
2236 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
2237 | * @client: Handle to slave device | |
2238 | * @command: Byte interpreted by slave | |
2239 | * @length: Size of data block; SMBus allows at most 32 bytes | |
2240 | * @values: Byte array which will be written. | |
2241 | * | |
2242 | * This executes the SMBus "block write" protocol, returning negative errno | |
2243 | * else zero on success. | |
2244 | */ | |
0cc43a18 | 2245 | s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command, |
46f5ed75 | 2246 | u8 length, const u8 *values) |
1da177e4 LT |
2247 | { |
2248 | union i2c_smbus_data data; | |
7656032b | 2249 | |
1da177e4 LT |
2250 | if (length > I2C_SMBUS_BLOCK_MAX) |
2251 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 2252 | data.block[0] = length; |
7656032b | 2253 | memcpy(&data.block[1], values, length); |
7225acf4 FH |
2254 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2255 | I2C_SMBUS_WRITE, command, | |
2256 | I2C_SMBUS_BLOCK_DATA, &data); | |
1da177e4 | 2257 | } |
c0564606 | 2258 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
2259 | |
2260 | /* Returns the number of read bytes */ | |
0cc43a18 | 2261 | s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command, |
4b2643d7 | 2262 | u8 length, u8 *values) |
1da177e4 LT |
2263 | { |
2264 | union i2c_smbus_data data; | |
24a5bb7b | 2265 | int status; |
7656032b | 2266 | |
4b2643d7 JD |
2267 | if (length > I2C_SMBUS_BLOCK_MAX) |
2268 | length = I2C_SMBUS_BLOCK_MAX; | |
2269 | data.block[0] = length; | |
24a5bb7b DB |
2270 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2271 | I2C_SMBUS_READ, command, | |
2272 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
2273 | if (status < 0) | |
2274 | return status; | |
7656032b JD |
2275 | |
2276 | memcpy(values, &data.block[1], data.block[0]); | |
2277 | return data.block[0]; | |
1da177e4 | 2278 | } |
c0564606 | 2279 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 2280 | |
0cc43a18 | 2281 | s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command, |
46f5ed75 | 2282 | u8 length, const u8 *values) |
21bbd691 JD |
2283 | { |
2284 | union i2c_smbus_data data; | |
2285 | ||
2286 | if (length > I2C_SMBUS_BLOCK_MAX) | |
2287 | length = I2C_SMBUS_BLOCK_MAX; | |
2288 | data.block[0] = length; | |
2289 | memcpy(data.block + 1, values, length); | |
2290 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2291 | I2C_SMBUS_WRITE, command, | |
2292 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
2293 | } | |
c0564606 | 2294 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 2295 | |
438d6c2c | 2296 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 2297 | No checking of parameters is done! */ |
7225acf4 FH |
2298 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, |
2299 | unsigned short flags, | |
2300 | char read_write, u8 command, int size, | |
2301 | union i2c_smbus_data *data) | |
1da177e4 LT |
2302 | { |
2303 | /* So we need to generate a series of msgs. In the case of writing, we | |
2304 | need to use only one message; when reading, we need two. We initialize | |
2305 | most things with sane defaults, to keep the code below somewhat | |
2306 | simpler. */ | |
5c50d188 HI |
2307 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
2308 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
7225acf4 | 2309 | int num = read_write == I2C_SMBUS_READ ? 2 : 1; |
1da177e4 | 2310 | int i; |
421ef47b | 2311 | u8 partial_pec = 0; |
24a5bb7b | 2312 | int status; |
230da094 S |
2313 | struct i2c_msg msg[2] = { |
2314 | { | |
2315 | .addr = addr, | |
2316 | .flags = flags, | |
2317 | .len = 1, | |
2318 | .buf = msgbuf0, | |
2319 | }, { | |
2320 | .addr = addr, | |
2321 | .flags = flags | I2C_M_RD, | |
2322 | .len = 0, | |
2323 | .buf = msgbuf1, | |
2324 | }, | |
2325 | }; | |
1da177e4 LT |
2326 | |
2327 | msgbuf0[0] = command; | |
7225acf4 | 2328 | switch (size) { |
1da177e4 LT |
2329 | case I2C_SMBUS_QUICK: |
2330 | msg[0].len = 0; | |
2331 | /* Special case: The read/write field is used as data */ | |
f29d2e02 RK |
2332 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
2333 | I2C_M_RD : 0); | |
1da177e4 LT |
2334 | num = 1; |
2335 | break; | |
2336 | case I2C_SMBUS_BYTE: | |
2337 | if (read_write == I2C_SMBUS_READ) { | |
2338 | /* Special case: only a read! */ | |
2339 | msg[0].flags = I2C_M_RD | flags; | |
2340 | num = 1; | |
2341 | } | |
2342 | break; | |
2343 | case I2C_SMBUS_BYTE_DATA: | |
2344 | if (read_write == I2C_SMBUS_READ) | |
2345 | msg[1].len = 1; | |
2346 | else { | |
2347 | msg[0].len = 2; | |
2348 | msgbuf0[1] = data->byte; | |
2349 | } | |
2350 | break; | |
2351 | case I2C_SMBUS_WORD_DATA: | |
2352 | if (read_write == I2C_SMBUS_READ) | |
2353 | msg[1].len = 2; | |
2354 | else { | |
7225acf4 | 2355 | msg[0].len = 3; |
1da177e4 | 2356 | msgbuf0[1] = data->word & 0xff; |
7eff82c8 | 2357 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
2358 | } |
2359 | break; | |
2360 | case I2C_SMBUS_PROC_CALL: | |
2361 | num = 2; /* Special case */ | |
2362 | read_write = I2C_SMBUS_READ; | |
2363 | msg[0].len = 3; | |
2364 | msg[1].len = 2; | |
2365 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 2366 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
2367 | break; |
2368 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 2369 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
2370 | msg[1].flags |= I2C_M_RECV_LEN; |
2371 | msg[1].len = 1; /* block length will be added by | |
2372 | the underlying bus driver */ | |
1da177e4 LT |
2373 | } else { |
2374 | msg[0].len = data->block[0] + 2; | |
2375 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
2376 | dev_err(&adapter->dev, |
2377 | "Invalid block write size %d\n", | |
2378 | data->block[0]); | |
2379 | return -EINVAL; | |
1da177e4 | 2380 | } |
5c50d188 | 2381 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
2382 | msgbuf0[i] = data->block[i-1]; |
2383 | } | |
2384 | break; | |
2385 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
2386 | num = 2; /* Another special case */ |
2387 | read_write = I2C_SMBUS_READ; | |
2388 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
2389 | dev_err(&adapter->dev, |
2390 | "Invalid block write size %d\n", | |
209d27c3 | 2391 | data->block[0]); |
24a5bb7b | 2392 | return -EINVAL; |
209d27c3 JD |
2393 | } |
2394 | msg[0].len = data->block[0] + 2; | |
2395 | for (i = 1; i < msg[0].len; i++) | |
2396 | msgbuf0[i] = data->block[i-1]; | |
2397 | msg[1].flags |= I2C_M_RECV_LEN; | |
2398 | msg[1].len = 1; /* block length will be added by | |
2399 | the underlying bus driver */ | |
2400 | break; | |
1da177e4 LT |
2401 | case I2C_SMBUS_I2C_BLOCK_DATA: |
2402 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 2403 | msg[1].len = data->block[0]; |
1da177e4 LT |
2404 | } else { |
2405 | msg[0].len = data->block[0] + 1; | |
30dac746 | 2406 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
2407 | dev_err(&adapter->dev, |
2408 | "Invalid block write size %d\n", | |
2409 | data->block[0]); | |
2410 | return -EINVAL; | |
1da177e4 LT |
2411 | } |
2412 | for (i = 1; i <= data->block[0]; i++) | |
2413 | msgbuf0[i] = data->block[i]; | |
2414 | } | |
2415 | break; | |
2416 | default: | |
24a5bb7b DB |
2417 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
2418 | return -EOPNOTSUPP; | |
1da177e4 LT |
2419 | } |
2420 | ||
421ef47b JD |
2421 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
2422 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
2423 | if (i) { | |
2424 | /* Compute PEC if first message is a write */ | |
2425 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 2426 | if (num == 1) /* Write only */ |
421ef47b JD |
2427 | i2c_smbus_add_pec(&msg[0]); |
2428 | else /* Write followed by read */ | |
2429 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
2430 | } | |
2431 | /* Ask for PEC if last message is a read */ | |
2432 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 2433 | msg[num-1].len++; |
421ef47b JD |
2434 | } |
2435 | ||
24a5bb7b DB |
2436 | status = i2c_transfer(adapter, msg, num); |
2437 | if (status < 0) | |
2438 | return status; | |
1da177e4 | 2439 | |
421ef47b JD |
2440 | /* Check PEC if last message is a read */ |
2441 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
2442 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
2443 | if (status < 0) | |
2444 | return status; | |
421ef47b JD |
2445 | } |
2446 | ||
1da177e4 | 2447 | if (read_write == I2C_SMBUS_READ) |
7225acf4 FH |
2448 | switch (size) { |
2449 | case I2C_SMBUS_BYTE: | |
2450 | data->byte = msgbuf0[0]; | |
2451 | break; | |
2452 | case I2C_SMBUS_BYTE_DATA: | |
2453 | data->byte = msgbuf1[0]; | |
2454 | break; | |
2455 | case I2C_SMBUS_WORD_DATA: | |
2456 | case I2C_SMBUS_PROC_CALL: | |
2457 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
2458 | break; | |
2459 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
2460 | for (i = 0; i < data->block[0]; i++) | |
2461 | data->block[i+1] = msgbuf1[i]; | |
2462 | break; | |
2463 | case I2C_SMBUS_BLOCK_DATA: | |
2464 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
2465 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
2466 | data->block[i] = msgbuf1[i]; | |
2467 | break; | |
1da177e4 LT |
2468 | } |
2469 | return 0; | |
2470 | } | |
2471 | ||
a1cdedac DB |
2472 | /** |
2473 | * i2c_smbus_xfer - execute SMBus protocol operations | |
2474 | * @adapter: Handle to I2C bus | |
2475 | * @addr: Address of SMBus slave on that bus | |
2476 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
2477 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
2478 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
2479 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
2480 | * @data: Data to be read or written | |
2481 | * | |
2482 | * This executes an SMBus protocol operation, and returns a negative | |
2483 | * errno code else zero on success. | |
2484 | */ | |
09b8ce0a | 2485 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
a1cdedac | 2486 | char read_write, u8 command, int protocol, |
09b8ce0a | 2487 | union i2c_smbus_data *data) |
1da177e4 | 2488 | { |
66b650f0 CW |
2489 | unsigned long orig_jiffies; |
2490 | int try; | |
1da177e4 | 2491 | s32 res; |
1da177e4 | 2492 | |
8a325997 DH |
2493 | /* If enabled, the following two tracepoints are conditional on |
2494 | * read_write and protocol. | |
2495 | */ | |
2496 | trace_smbus_write(adapter, addr, flags, read_write, | |
2497 | command, protocol, data); | |
2498 | trace_smbus_read(adapter, addr, flags, read_write, | |
2499 | command, protocol); | |
2500 | ||
d47726c5 | 2501 | flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB; |
1da177e4 LT |
2502 | |
2503 | if (adapter->algo->smbus_xfer) { | |
fe61e07e | 2504 | i2c_lock_adapter(adapter); |
66b650f0 CW |
2505 | |
2506 | /* Retry automatically on arbitration loss */ | |
2507 | orig_jiffies = jiffies; | |
2508 | for (res = 0, try = 0; try <= adapter->retries; try++) { | |
2509 | res = adapter->algo->smbus_xfer(adapter, addr, flags, | |
2510 | read_write, command, | |
2511 | protocol, data); | |
2512 | if (res != -EAGAIN) | |
2513 | break; | |
2514 | if (time_after(jiffies, | |
2515 | orig_jiffies + adapter->timeout)) | |
2516 | break; | |
2517 | } | |
fe61e07e | 2518 | i2c_unlock_adapter(adapter); |
1da177e4 | 2519 | |
72fc2c7f | 2520 | if (res != -EOPNOTSUPP || !adapter->algo->master_xfer) |
8a325997 | 2521 | goto trace; |
72fc2c7f LP |
2522 | /* |
2523 | * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't | |
2524 | * implement native support for the SMBus operation. | |
2525 | */ | |
2526 | } | |
2527 | ||
8a325997 DH |
2528 | res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, |
2529 | command, protocol, data); | |
2530 | ||
2531 | trace: | |
2532 | /* If enabled, the reply tracepoint is conditional on read_write. */ | |
2533 | trace_smbus_reply(adapter, addr, flags, read_write, | |
2534 | command, protocol, data); | |
2535 | trace_smbus_result(adapter, addr, flags, read_write, | |
2536 | command, protocol, res); | |
2537 | ||
2538 | return res; | |
1da177e4 | 2539 | } |
1da177e4 | 2540 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
2541 | |
2542 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
2543 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
2544 | MODULE_LICENSE("GPL"); |