]>
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> |
b8d6f45b | 45 | #include <linux/completion.h> |
cea443a8 MR |
46 | #include <linux/hardirq.h> |
47 | #include <linux/irqflags.h> | |
f18c41da | 48 | #include <linux/rwsem.h> |
6de468ae | 49 | #include <linux/pm_runtime.h> |
907ddf89 | 50 | #include <linux/acpi.h> |
d9a83d62 | 51 | #include <linux/jump_label.h> |
1da177e4 LT |
52 | #include <asm/uaccess.h> |
53 | ||
9c1600ed DB |
54 | #include "i2c-core.h" |
55 | ||
d9a83d62 DH |
56 | #define CREATE_TRACE_POINTS |
57 | #include <trace/events/i2c.h> | |
1da177e4 | 58 | |
6629dcff | 59 | /* core_lock protects i2c_adapter_idr, and guarantees |
35fc37f8 | 60 | that device detection, deletion of detected devices, and attach_adapter |
19baba4c | 61 | calls are serialized */ |
caada32a | 62 | static DEFINE_MUTEX(core_lock); |
1da177e4 LT |
63 | static DEFINE_IDR(i2c_adapter_idr); |
64 | ||
4f8cf824 | 65 | static struct device_type i2c_client_type; |
4735c98f | 66 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
f37dd80a | 67 | |
d9a83d62 DH |
68 | static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE; |
69 | ||
70 | void i2c_transfer_trace_reg(void) | |
71 | { | |
72 | static_key_slow_inc(&i2c_trace_msg); | |
73 | } | |
74 | ||
75 | void i2c_transfer_trace_unreg(void) | |
76 | { | |
77 | static_key_slow_dec(&i2c_trace_msg); | |
78 | } | |
79 | ||
f37dd80a DB |
80 | /* ------------------------------------------------------------------------- */ |
81 | ||
d2653e92 JD |
82 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
83 | const struct i2c_client *client) | |
84 | { | |
85 | while (id->name[0]) { | |
86 | if (strcmp(client->name, id->name) == 0) | |
87 | return id; | |
88 | id++; | |
89 | } | |
90 | return NULL; | |
91 | } | |
92 | ||
1da177e4 LT |
93 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
94 | { | |
51298d12 JD |
95 | struct i2c_client *client = i2c_verify_client(dev); |
96 | struct i2c_driver *driver; | |
97 | ||
98 | if (!client) | |
99 | return 0; | |
7b4fbc50 | 100 | |
959e85f7 GL |
101 | /* Attempt an OF style match */ |
102 | if (of_driver_match_device(dev, drv)) | |
103 | return 1; | |
104 | ||
907ddf89 MW |
105 | /* Then ACPI style match */ |
106 | if (acpi_driver_match_device(dev, drv)) | |
107 | return 1; | |
108 | ||
51298d12 | 109 | driver = to_i2c_driver(drv); |
d2653e92 JD |
110 | /* match on an id table if there is one */ |
111 | if (driver->id_table) | |
112 | return i2c_match_id(driver->id_table, client) != NULL; | |
113 | ||
eb8a7908 | 114 | return 0; |
1da177e4 LT |
115 | } |
116 | ||
7b4fbc50 DB |
117 | |
118 | /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ | |
7eff2e7a | 119 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 DB |
120 | { |
121 | struct i2c_client *client = to_i2c_client(dev); | |
8c4ff6d0 ZR |
122 | int rc; |
123 | ||
124 | rc = acpi_device_uevent_modalias(dev, env); | |
125 | if (rc != -ENODEV) | |
126 | return rc; | |
7b4fbc50 | 127 | |
eb8a7908 JD |
128 | if (add_uevent_var(env, "MODALIAS=%s%s", |
129 | I2C_MODULE_PREFIX, client->name)) | |
130 | return -ENOMEM; | |
7b4fbc50 DB |
131 | dev_dbg(dev, "uevent\n"); |
132 | return 0; | |
133 | } | |
134 | ||
5f9296ba VK |
135 | /* i2c bus recovery routines */ |
136 | static int get_scl_gpio_value(struct i2c_adapter *adap) | |
137 | { | |
138 | return gpio_get_value(adap->bus_recovery_info->scl_gpio); | |
139 | } | |
140 | ||
141 | static void set_scl_gpio_value(struct i2c_adapter *adap, int val) | |
142 | { | |
143 | gpio_set_value(adap->bus_recovery_info->scl_gpio, val); | |
144 | } | |
145 | ||
146 | static int get_sda_gpio_value(struct i2c_adapter *adap) | |
147 | { | |
148 | return gpio_get_value(adap->bus_recovery_info->sda_gpio); | |
149 | } | |
150 | ||
151 | static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap) | |
152 | { | |
153 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
154 | struct device *dev = &adap->dev; | |
155 | int ret = 0; | |
156 | ||
157 | ret = gpio_request_one(bri->scl_gpio, GPIOF_OPEN_DRAIN | | |
158 | GPIOF_OUT_INIT_HIGH, "i2c-scl"); | |
159 | if (ret) { | |
160 | dev_warn(dev, "Can't get SCL gpio: %d\n", bri->scl_gpio); | |
161 | return ret; | |
162 | } | |
163 | ||
164 | if (bri->get_sda) { | |
165 | if (gpio_request_one(bri->sda_gpio, GPIOF_IN, "i2c-sda")) { | |
166 | /* work without SDA polling */ | |
167 | dev_warn(dev, "Can't get SDA gpio: %d. Not using SDA polling\n", | |
168 | bri->sda_gpio); | |
169 | bri->get_sda = NULL; | |
170 | } | |
171 | } | |
172 | ||
173 | return ret; | |
174 | } | |
175 | ||
176 | static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap) | |
177 | { | |
178 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
179 | ||
180 | if (bri->get_sda) | |
181 | gpio_free(bri->sda_gpio); | |
182 | ||
183 | gpio_free(bri->scl_gpio); | |
184 | } | |
185 | ||
186 | /* | |
187 | * We are generating clock pulses. ndelay() determines durating of clk pulses. | |
188 | * We will generate clock with rate 100 KHz and so duration of both clock levels | |
189 | * is: delay in ns = (10^6 / 100) / 2 | |
190 | */ | |
191 | #define RECOVERY_NDELAY 5000 | |
192 | #define RECOVERY_CLK_CNT 9 | |
193 | ||
194 | static int i2c_generic_recovery(struct i2c_adapter *adap) | |
195 | { | |
196 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
197 | int i = 0, val = 1, ret = 0; | |
198 | ||
199 | if (bri->prepare_recovery) | |
200 | bri->prepare_recovery(bri); | |
201 | ||
202 | /* | |
203 | * By this time SCL is high, as we need to give 9 falling-rising edges | |
204 | */ | |
205 | while (i++ < RECOVERY_CLK_CNT * 2) { | |
206 | if (val) { | |
207 | /* Break if SDA is high */ | |
208 | if (bri->get_sda && bri->get_sda(adap)) | |
209 | break; | |
210 | /* SCL shouldn't be low here */ | |
211 | if (!bri->get_scl(adap)) { | |
212 | dev_err(&adap->dev, | |
213 | "SCL is stuck low, exit recovery\n"); | |
214 | ret = -EBUSY; | |
215 | break; | |
216 | } | |
217 | } | |
218 | ||
219 | val = !val; | |
220 | bri->set_scl(adap, val); | |
221 | ndelay(RECOVERY_NDELAY); | |
222 | } | |
223 | ||
224 | if (bri->unprepare_recovery) | |
225 | bri->unprepare_recovery(bri); | |
226 | ||
227 | return ret; | |
228 | } | |
229 | ||
230 | int i2c_generic_scl_recovery(struct i2c_adapter *adap) | |
231 | { | |
232 | adap->bus_recovery_info->set_scl(adap, 1); | |
233 | return i2c_generic_recovery(adap); | |
234 | } | |
235 | ||
236 | int i2c_generic_gpio_recovery(struct i2c_adapter *adap) | |
237 | { | |
238 | int ret; | |
239 | ||
240 | ret = i2c_get_gpios_for_recovery(adap); | |
241 | if (ret) | |
242 | return ret; | |
243 | ||
244 | ret = i2c_generic_recovery(adap); | |
245 | i2c_put_gpios_for_recovery(adap); | |
246 | ||
247 | return ret; | |
248 | } | |
249 | ||
250 | int i2c_recover_bus(struct i2c_adapter *adap) | |
251 | { | |
252 | if (!adap->bus_recovery_info) | |
253 | return -EOPNOTSUPP; | |
254 | ||
255 | dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); | |
256 | return adap->bus_recovery_info->recover_bus(adap); | |
257 | } | |
258 | ||
f37dd80a | 259 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 260 | { |
51298d12 JD |
261 | struct i2c_client *client = i2c_verify_client(dev); |
262 | struct i2c_driver *driver; | |
50c3304a | 263 | int status; |
7b4fbc50 | 264 | |
51298d12 JD |
265 | if (!client) |
266 | return 0; | |
267 | ||
268 | driver = to_i2c_driver(dev->driver); | |
e0457442 | 269 | if (!driver->probe || !driver->id_table) |
7b4fbc50 | 270 | return -ENODEV; |
0acc2b32 | 271 | |
ee35425c MP |
272 | if (!device_can_wakeup(&client->dev)) |
273 | device_init_wakeup(&client->dev, | |
274 | client->flags & I2C_CLIENT_WAKE); | |
7b4fbc50 | 275 | dev_dbg(dev, "probe\n"); |
d2653e92 | 276 | |
a76e9bd8 | 277 | acpi_dev_pm_attach(&client->dev, true); |
e0457442 | 278 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
72fa818e | 279 | if (status) |
a76e9bd8 | 280 | acpi_dev_pm_detach(&client->dev, true); |
72fa818e | 281 | |
50c3304a | 282 | return status; |
f37dd80a | 283 | } |
1da177e4 | 284 | |
f37dd80a DB |
285 | static int i2c_device_remove(struct device *dev) |
286 | { | |
51298d12 | 287 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 | 288 | struct i2c_driver *driver; |
72fa818e | 289 | int status = 0; |
a1d9e6e4 | 290 | |
51298d12 | 291 | if (!client || !dev->driver) |
a1d9e6e4 DB |
292 | return 0; |
293 | ||
294 | driver = to_i2c_driver(dev->driver); | |
295 | if (driver->remove) { | |
296 | dev_dbg(dev, "remove\n"); | |
297 | status = driver->remove(client); | |
a1d9e6e4 | 298 | } |
72fa818e | 299 | |
a76e9bd8 | 300 | acpi_dev_pm_detach(&client->dev, true); |
a1d9e6e4 | 301 | return status; |
1da177e4 LT |
302 | } |
303 | ||
f37dd80a | 304 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 305 | { |
51298d12 | 306 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
307 | struct i2c_driver *driver; |
308 | ||
51298d12 | 309 | if (!client || !dev->driver) |
f37dd80a DB |
310 | return; |
311 | driver = to_i2c_driver(dev->driver); | |
312 | if (driver->shutdown) | |
51298d12 | 313 | driver->shutdown(client); |
1da177e4 LT |
314 | } |
315 | ||
2f60ba70 RW |
316 | #ifdef CONFIG_PM_SLEEP |
317 | static int i2c_legacy_suspend(struct device *dev, pm_message_t mesg) | |
54067ee2 | 318 | { |
2f60ba70 RW |
319 | struct i2c_client *client = i2c_verify_client(dev); |
320 | struct i2c_driver *driver; | |
54067ee2 | 321 | |
2f60ba70 | 322 | if (!client || !dev->driver) |
54067ee2 | 323 | return 0; |
2f60ba70 RW |
324 | driver = to_i2c_driver(dev->driver); |
325 | if (!driver->suspend) | |
54067ee2 | 326 | return 0; |
2f60ba70 | 327 | return driver->suspend(client, mesg); |
54067ee2 | 328 | } |
329 | ||
2f60ba70 | 330 | static int i2c_legacy_resume(struct device *dev) |
54067ee2 | 331 | { |
2f60ba70 RW |
332 | struct i2c_client *client = i2c_verify_client(dev); |
333 | struct i2c_driver *driver; | |
54067ee2 | 334 | |
2f60ba70 | 335 | if (!client || !dev->driver) |
54067ee2 | 336 | return 0; |
2f60ba70 RW |
337 | driver = to_i2c_driver(dev->driver); |
338 | if (!driver->resume) | |
54067ee2 | 339 | return 0; |
2f60ba70 | 340 | return driver->resume(client); |
54067ee2 | 341 | } |
54067ee2 | 342 | |
2f60ba70 | 343 | static int i2c_device_pm_suspend(struct device *dev) |
6de468ae | 344 | { |
2f60ba70 | 345 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 346 | |
d529de29 MB |
347 | if (pm) |
348 | return pm_generic_suspend(dev); | |
349 | else | |
350 | return i2c_legacy_suspend(dev, PMSG_SUSPEND); | |
6de468ae MB |
351 | } |
352 | ||
2f60ba70 | 353 | static int i2c_device_pm_resume(struct device *dev) |
6de468ae | 354 | { |
2f60ba70 | 355 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 356 | |
2f60ba70 | 357 | if (pm) |
d529de29 | 358 | return pm_generic_resume(dev); |
2f60ba70 | 359 | else |
d529de29 | 360 | return i2c_legacy_resume(dev); |
6de468ae | 361 | } |
6de468ae | 362 | |
2f60ba70 | 363 | static int i2c_device_pm_freeze(struct device *dev) |
1da177e4 | 364 | { |
2f60ba70 | 365 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 366 | |
d529de29 MB |
367 | if (pm) |
368 | return pm_generic_freeze(dev); | |
369 | else | |
370 | return i2c_legacy_suspend(dev, PMSG_FREEZE); | |
1da177e4 LT |
371 | } |
372 | ||
2f60ba70 | 373 | static int i2c_device_pm_thaw(struct device *dev) |
1da177e4 | 374 | { |
2f60ba70 | 375 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 376 | |
d529de29 MB |
377 | if (pm) |
378 | return pm_generic_thaw(dev); | |
379 | else | |
380 | return i2c_legacy_resume(dev); | |
2f60ba70 RW |
381 | } |
382 | ||
383 | static int i2c_device_pm_poweroff(struct device *dev) | |
384 | { | |
385 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
386 | ||
d529de29 MB |
387 | if (pm) |
388 | return pm_generic_poweroff(dev); | |
389 | else | |
390 | return i2c_legacy_suspend(dev, PMSG_HIBERNATE); | |
2f60ba70 RW |
391 | } |
392 | ||
393 | static int i2c_device_pm_restore(struct device *dev) | |
394 | { | |
395 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
2f60ba70 RW |
396 | |
397 | if (pm) | |
d529de29 | 398 | return pm_generic_restore(dev); |
2f60ba70 | 399 | else |
d529de29 | 400 | return i2c_legacy_resume(dev); |
1da177e4 | 401 | } |
2f60ba70 RW |
402 | #else /* !CONFIG_PM_SLEEP */ |
403 | #define i2c_device_pm_suspend NULL | |
404 | #define i2c_device_pm_resume NULL | |
405 | #define i2c_device_pm_freeze NULL | |
406 | #define i2c_device_pm_thaw NULL | |
407 | #define i2c_device_pm_poweroff NULL | |
408 | #define i2c_device_pm_restore NULL | |
409 | #endif /* !CONFIG_PM_SLEEP */ | |
1da177e4 | 410 | |
9c1600ed DB |
411 | static void i2c_client_dev_release(struct device *dev) |
412 | { | |
413 | kfree(to_i2c_client(dev)); | |
414 | } | |
415 | ||
09b8ce0a | 416 | static ssize_t |
4f8cf824 | 417 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 418 | { |
4f8cf824 JD |
419 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
420 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 DB |
421 | } |
422 | ||
09b8ce0a ZX |
423 | static ssize_t |
424 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
425 | { |
426 | struct i2c_client *client = to_i2c_client(dev); | |
8c4ff6d0 ZR |
427 | int len; |
428 | ||
429 | len = acpi_device_modalias(dev, buf, PAGE_SIZE -1); | |
430 | if (len != -ENODEV) | |
431 | return len; | |
432 | ||
eb8a7908 | 433 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
434 | } |
435 | ||
4f8cf824 | 436 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
51298d12 JD |
437 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
438 | ||
439 | static struct attribute *i2c_dev_attrs[] = { | |
440 | &dev_attr_name.attr, | |
7b4fbc50 | 441 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
442 | &dev_attr_modalias.attr, |
443 | NULL | |
444 | }; | |
445 | ||
446 | static struct attribute_group i2c_dev_attr_group = { | |
447 | .attrs = i2c_dev_attrs, | |
448 | }; | |
449 | ||
450 | static const struct attribute_group *i2c_dev_attr_groups[] = { | |
451 | &i2c_dev_attr_group, | |
452 | NULL | |
7b4fbc50 DB |
453 | }; |
454 | ||
0b2c3688 | 455 | static const struct dev_pm_ops i2c_device_pm_ops = { |
54067ee2 | 456 | .suspend = i2c_device_pm_suspend, |
457 | .resume = i2c_device_pm_resume, | |
2f60ba70 RW |
458 | .freeze = i2c_device_pm_freeze, |
459 | .thaw = i2c_device_pm_thaw, | |
460 | .poweroff = i2c_device_pm_poweroff, | |
461 | .restore = i2c_device_pm_restore, | |
462 | SET_RUNTIME_PM_OPS( | |
463 | pm_generic_runtime_suspend, | |
464 | pm_generic_runtime_resume, | |
45f0a85c | 465 | NULL |
2f60ba70 | 466 | ) |
54067ee2 | 467 | }; |
468 | ||
e9ca9eb9 | 469 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
470 | .name = "i2c", |
471 | .match = i2c_device_match, | |
472 | .probe = i2c_device_probe, | |
473 | .remove = i2c_device_remove, | |
474 | .shutdown = i2c_device_shutdown, | |
54067ee2 | 475 | .pm = &i2c_device_pm_ops, |
b864c7d5 | 476 | }; |
e9ca9eb9 | 477 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 478 | |
51298d12 JD |
479 | static struct device_type i2c_client_type = { |
480 | .groups = i2c_dev_attr_groups, | |
481 | .uevent = i2c_device_uevent, | |
482 | .release = i2c_client_dev_release, | |
483 | }; | |
484 | ||
9b766b81 DB |
485 | |
486 | /** | |
487 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
488 | * @dev: device, probably from some driver model iterator | |
489 | * | |
490 | * When traversing the driver model tree, perhaps using driver model | |
491 | * iterators like @device_for_each_child(), you can't assume very much | |
492 | * about the nodes you find. Use this function to avoid oopses caused | |
493 | * by wrongly treating some non-I2C device as an i2c_client. | |
494 | */ | |
495 | struct i2c_client *i2c_verify_client(struct device *dev) | |
496 | { | |
51298d12 | 497 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
498 | ? to_i2c_client(dev) |
499 | : NULL; | |
500 | } | |
501 | EXPORT_SYMBOL(i2c_verify_client); | |
502 | ||
503 | ||
3a89db5f | 504 | /* This is a permissive address validity check, I2C address map constraints |
25985edc | 505 | * are purposely not enforced, except for the general call address. */ |
3a89db5f JD |
506 | static int i2c_check_client_addr_validity(const struct i2c_client *client) |
507 | { | |
508 | if (client->flags & I2C_CLIENT_TEN) { | |
509 | /* 10-bit address, all values are valid */ | |
510 | if (client->addr > 0x3ff) | |
511 | return -EINVAL; | |
512 | } else { | |
513 | /* 7-bit address, reject the general call address */ | |
514 | if (client->addr == 0x00 || client->addr > 0x7f) | |
515 | return -EINVAL; | |
516 | } | |
517 | return 0; | |
518 | } | |
519 | ||
656b8761 JD |
520 | /* And this is a strict address validity check, used when probing. If a |
521 | * device uses a reserved address, then it shouldn't be probed. 7-bit | |
522 | * addressing is assumed, 10-bit address devices are rare and should be | |
523 | * explicitly enumerated. */ | |
524 | static int i2c_check_addr_validity(unsigned short addr) | |
525 | { | |
526 | /* | |
527 | * Reserved addresses per I2C specification: | |
528 | * 0x00 General call address / START byte | |
529 | * 0x01 CBUS address | |
530 | * 0x02 Reserved for different bus format | |
531 | * 0x03 Reserved for future purposes | |
532 | * 0x04-0x07 Hs-mode master code | |
533 | * 0x78-0x7b 10-bit slave addressing | |
534 | * 0x7c-0x7f Reserved for future purposes | |
535 | */ | |
536 | if (addr < 0x08 || addr > 0x77) | |
537 | return -EINVAL; | |
538 | return 0; | |
539 | } | |
540 | ||
3b5f794b JD |
541 | static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
542 | { | |
543 | struct i2c_client *client = i2c_verify_client(dev); | |
544 | int addr = *(int *)addrp; | |
545 | ||
546 | if (client && client->addr == addr) | |
547 | return -EBUSY; | |
548 | return 0; | |
549 | } | |
550 | ||
0826374b ML |
551 | /* walk up mux tree */ |
552 | static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
553 | { | |
97cc4d49 | 554 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
555 | int result; |
556 | ||
557 | result = device_for_each_child(&adapter->dev, &addr, | |
558 | __i2c_check_addr_busy); | |
559 | ||
97cc4d49 JD |
560 | if (!result && parent) |
561 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
562 | |
563 | return result; | |
564 | } | |
565 | ||
566 | /* recurse down mux tree */ | |
567 | static int i2c_check_mux_children(struct device *dev, void *addrp) | |
568 | { | |
569 | int result; | |
570 | ||
571 | if (dev->type == &i2c_adapter_type) | |
572 | result = device_for_each_child(dev, addrp, | |
573 | i2c_check_mux_children); | |
574 | else | |
575 | result = __i2c_check_addr_busy(dev, addrp); | |
576 | ||
577 | return result; | |
578 | } | |
579 | ||
3b5f794b JD |
580 | static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) |
581 | { | |
97cc4d49 | 582 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
583 | int result = 0; |
584 | ||
97cc4d49 JD |
585 | if (parent) |
586 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
587 | |
588 | if (!result) | |
589 | result = device_for_each_child(&adapter->dev, &addr, | |
590 | i2c_check_mux_children); | |
591 | ||
592 | return result; | |
3b5f794b JD |
593 | } |
594 | ||
fe61e07e JD |
595 | /** |
596 | * i2c_lock_adapter - Get exclusive access to an I2C bus segment | |
597 | * @adapter: Target I2C bus segment | |
598 | */ | |
599 | void i2c_lock_adapter(struct i2c_adapter *adapter) | |
600 | { | |
97cc4d49 JD |
601 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
602 | ||
603 | if (parent) | |
604 | i2c_lock_adapter(parent); | |
0826374b ML |
605 | else |
606 | rt_mutex_lock(&adapter->bus_lock); | |
fe61e07e JD |
607 | } |
608 | EXPORT_SYMBOL_GPL(i2c_lock_adapter); | |
609 | ||
610 | /** | |
611 | * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment | |
612 | * @adapter: Target I2C bus segment | |
613 | */ | |
614 | static int i2c_trylock_adapter(struct i2c_adapter *adapter) | |
615 | { | |
97cc4d49 JD |
616 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
617 | ||
618 | if (parent) | |
619 | return i2c_trylock_adapter(parent); | |
0826374b ML |
620 | else |
621 | return rt_mutex_trylock(&adapter->bus_lock); | |
fe61e07e JD |
622 | } |
623 | ||
624 | /** | |
625 | * i2c_unlock_adapter - Release exclusive access to an I2C bus segment | |
626 | * @adapter: Target I2C bus segment | |
627 | */ | |
628 | void i2c_unlock_adapter(struct i2c_adapter *adapter) | |
629 | { | |
97cc4d49 JD |
630 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
631 | ||
632 | if (parent) | |
633 | i2c_unlock_adapter(parent); | |
0826374b ML |
634 | else |
635 | rt_mutex_unlock(&adapter->bus_lock); | |
fe61e07e JD |
636 | } |
637 | EXPORT_SYMBOL_GPL(i2c_unlock_adapter); | |
638 | ||
70762abb JN |
639 | static void i2c_dev_set_name(struct i2c_adapter *adap, |
640 | struct i2c_client *client) | |
641 | { | |
642 | struct acpi_device *adev = ACPI_COMPANION(&client->dev); | |
643 | ||
644 | if (adev) { | |
645 | dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); | |
646 | return; | |
647 | } | |
648 | ||
649 | /* For 10-bit clients, add an arbitrary offset to avoid collisions */ | |
650 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), | |
651 | client->addr | ((client->flags & I2C_CLIENT_TEN) | |
652 | ? 0xa000 : 0)); | |
653 | } | |
654 | ||
9c1600ed | 655 | /** |
f8a227e8 | 656 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
657 | * @adap: the adapter managing the device |
658 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 659 | * Context: can sleep |
9c1600ed | 660 | * |
f8a227e8 JD |
661 | * Create an i2c device. Binding is handled through driver model |
662 | * probe()/remove() methods. A driver may be bound to this device when we | |
663 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
664 | * load the driver module). This call is not appropriate for use by mainboard | |
665 | * initialization logic, which usually runs during an arch_initcall() long | |
666 | * before any i2c_adapter could exist. | |
9c1600ed DB |
667 | * |
668 | * This returns the new i2c client, which may be saved for later use with | |
669 | * i2c_unregister_device(); or NULL to indicate an error. | |
670 | */ | |
671 | struct i2c_client * | |
672 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
673 | { | |
674 | struct i2c_client *client; | |
675 | int status; | |
676 | ||
677 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
678 | if (!client) | |
679 | return NULL; | |
680 | ||
681 | client->adapter = adap; | |
682 | ||
683 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 684 | |
11f1f2af AV |
685 | if (info->archdata) |
686 | client->dev.archdata = *info->archdata; | |
687 | ||
ee35425c | 688 | client->flags = info->flags; |
9c1600ed DB |
689 | client->addr = info->addr; |
690 | client->irq = info->irq; | |
691 | ||
9c1600ed DB |
692 | strlcpy(client->name, info->type, sizeof(client->name)); |
693 | ||
3a89db5f JD |
694 | /* Check for address validity */ |
695 | status = i2c_check_client_addr_validity(client); | |
696 | if (status) { | |
697 | dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", | |
698 | client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); | |
699 | goto out_err_silent; | |
700 | } | |
701 | ||
f8a227e8 | 702 | /* Check for address business */ |
3b5f794b | 703 | status = i2c_check_addr_busy(adap, client->addr); |
f8a227e8 JD |
704 | if (status) |
705 | goto out_err; | |
706 | ||
707 | client->dev.parent = &client->adapter->dev; | |
708 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 709 | client->dev.type = &i2c_client_type; |
d12d42f7 | 710 | client->dev.of_node = info->of_node; |
7b199811 | 711 | ACPI_COMPANION_SET(&client->dev, info->acpi_node.companion); |
f8a227e8 | 712 | |
70762abb | 713 | i2c_dev_set_name(adap, client); |
f8a227e8 JD |
714 | status = device_register(&client->dev); |
715 | if (status) | |
716 | goto out_err; | |
717 | ||
f8a227e8 JD |
718 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
719 | client->name, dev_name(&client->dev)); | |
720 | ||
9c1600ed | 721 | return client; |
f8a227e8 JD |
722 | |
723 | out_err: | |
724 | dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " | |
725 | "(%d)\n", client->name, client->addr, status); | |
3a89db5f | 726 | out_err_silent: |
f8a227e8 JD |
727 | kfree(client); |
728 | return NULL; | |
9c1600ed DB |
729 | } |
730 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
731 | ||
732 | ||
733 | /** | |
734 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
735 | * @client: value returned from i2c_new_device() | |
d64f73be | 736 | * Context: can sleep |
9c1600ed DB |
737 | */ |
738 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 739 | { |
a1d9e6e4 DB |
740 | device_unregister(&client->dev); |
741 | } | |
9c1600ed | 742 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
743 | |
744 | ||
60b129d7 JD |
745 | static const struct i2c_device_id dummy_id[] = { |
746 | { "dummy", 0 }, | |
747 | { }, | |
748 | }; | |
749 | ||
d2653e92 JD |
750 | static int dummy_probe(struct i2c_client *client, |
751 | const struct i2c_device_id *id) | |
752 | { | |
753 | return 0; | |
754 | } | |
755 | ||
756 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
757 | { |
758 | return 0; | |
759 | } | |
760 | ||
761 | static struct i2c_driver dummy_driver = { | |
762 | .driver.name = "dummy", | |
d2653e92 JD |
763 | .probe = dummy_probe, |
764 | .remove = dummy_remove, | |
60b129d7 | 765 | .id_table = dummy_id, |
e9f1373b DB |
766 | }; |
767 | ||
768 | /** | |
769 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
770 | * @adapter: the adapter managing the device | |
771 | * @address: seven bit address to be used | |
e9f1373b DB |
772 | * Context: can sleep |
773 | * | |
774 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
775 | * with devices that consume multiple addresses. Examples of such chips | |
776 | * include various EEPROMS (like 24c04 and 24c08 models). | |
777 | * | |
778 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
779 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
780 | * And second, this prevents the specified address from being bound to a | |
781 | * different driver. | |
782 | * | |
783 | * This returns the new i2c client, which should be saved for later use with | |
784 | * i2c_unregister_device(); or NULL to indicate an error. | |
785 | */ | |
09b8ce0a | 786 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
787 | { |
788 | struct i2c_board_info info = { | |
60b129d7 | 789 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
790 | }; |
791 | ||
e9f1373b DB |
792 | return i2c_new_device(adapter, &info); |
793 | } | |
794 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
795 | ||
f37dd80a DB |
796 | /* ------------------------------------------------------------------------- */ |
797 | ||
16ffadfc DB |
798 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
799 | ||
83eaaed0 | 800 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 801 | { |
ef2c8321 | 802 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
803 | complete(&adap->dev_released); |
804 | } | |
805 | ||
390946b1 JD |
806 | /* |
807 | * This function is only needed for mutex_lock_nested, so it is never | |
808 | * called unless locking correctness checking is enabled. Thus we | |
809 | * make it inline to avoid a compiler warning. That's what gcc ends up | |
810 | * doing anyway. | |
811 | */ | |
812 | static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) | |
813 | { | |
814 | unsigned int depth = 0; | |
815 | ||
816 | while ((adapter = i2c_parent_is_i2c_adapter(adapter))) | |
817 | depth++; | |
818 | ||
819 | return depth; | |
820 | } | |
821 | ||
99cd8e25 JD |
822 | /* |
823 | * Let users instantiate I2C devices through sysfs. This can be used when | |
824 | * platform initialization code doesn't contain the proper data for | |
825 | * whatever reason. Also useful for drivers that do device detection and | |
826 | * detection fails, either because the device uses an unexpected address, | |
827 | * or this is a compatible device with different ID register values. | |
828 | * | |
829 | * Parameter checking may look overzealous, but we really don't want | |
830 | * the user to provide incorrect parameters. | |
831 | */ | |
832 | static ssize_t | |
833 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
834 | const char *buf, size_t count) | |
835 | { | |
836 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
837 | struct i2c_board_info info; | |
838 | struct i2c_client *client; | |
839 | char *blank, end; | |
840 | int res; | |
841 | ||
99cd8e25 JD |
842 | memset(&info, 0, sizeof(struct i2c_board_info)); |
843 | ||
844 | blank = strchr(buf, ' '); | |
845 | if (!blank) { | |
846 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
847 | return -EINVAL; | |
848 | } | |
849 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
850 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
851 | return -EINVAL; | |
852 | } | |
853 | memcpy(info.type, buf, blank - buf); | |
854 | ||
855 | /* Parse remaining parameters, reject extra parameters */ | |
856 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
857 | if (res < 1) { | |
858 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
859 | return -EINVAL; | |
860 | } | |
861 | if (res > 1 && end != '\n') { | |
862 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
863 | return -EINVAL; | |
864 | } | |
865 | ||
99cd8e25 JD |
866 | client = i2c_new_device(adap, &info); |
867 | if (!client) | |
3a89db5f | 868 | return -EINVAL; |
99cd8e25 JD |
869 | |
870 | /* Keep track of the added device */ | |
dafc50d1 | 871 | mutex_lock(&adap->userspace_clients_lock); |
6629dcff | 872 | list_add_tail(&client->detected, &adap->userspace_clients); |
dafc50d1 | 873 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
874 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
875 | info.type, info.addr); | |
876 | ||
877 | return count; | |
878 | } | |
879 | ||
880 | /* | |
881 | * And of course let the users delete the devices they instantiated, if | |
882 | * they got it wrong. This interface can only be used to delete devices | |
883 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
884 | * don't delete devices to which some kernel code still has references. | |
885 | * | |
886 | * Parameter checking may look overzealous, but we really don't want | |
887 | * the user to delete the wrong device. | |
888 | */ | |
889 | static ssize_t | |
890 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
891 | const char *buf, size_t count) | |
892 | { | |
893 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
894 | struct i2c_client *client, *next; | |
895 | unsigned short addr; | |
896 | char end; | |
897 | int res; | |
898 | ||
899 | /* Parse parameters, reject extra parameters */ | |
900 | res = sscanf(buf, "%hi%c", &addr, &end); | |
901 | if (res < 1) { | |
902 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
903 | return -EINVAL; | |
904 | } | |
905 | if (res > 1 && end != '\n') { | |
906 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
907 | return -EINVAL; | |
908 | } | |
909 | ||
910 | /* Make sure the device was added through sysfs */ | |
911 | res = -ENOENT; | |
390946b1 JD |
912 | mutex_lock_nested(&adap->userspace_clients_lock, |
913 | i2c_adapter_depth(adap)); | |
6629dcff JD |
914 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
915 | detected) { | |
916 | if (client->addr == addr) { | |
99cd8e25 JD |
917 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
918 | "delete_device", client->name, client->addr); | |
919 | ||
920 | list_del(&client->detected); | |
921 | i2c_unregister_device(client); | |
922 | res = count; | |
923 | break; | |
924 | } | |
925 | } | |
dafc50d1 | 926 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
927 | |
928 | if (res < 0) | |
929 | dev_err(dev, "%s: Can't find device in list\n", | |
930 | "delete_device"); | |
931 | return res; | |
932 | } | |
933 | ||
4f8cf824 | 934 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
e9b526fe AS |
935 | static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, |
936 | i2c_sysfs_delete_device); | |
4f8cf824 JD |
937 | |
938 | static struct attribute *i2c_adapter_attrs[] = { | |
939 | &dev_attr_name.attr, | |
940 | &dev_attr_new_device.attr, | |
941 | &dev_attr_delete_device.attr, | |
942 | NULL | |
943 | }; | |
944 | ||
945 | static struct attribute_group i2c_adapter_attr_group = { | |
946 | .attrs = i2c_adapter_attrs, | |
947 | }; | |
948 | ||
949 | static const struct attribute_group *i2c_adapter_attr_groups[] = { | |
950 | &i2c_adapter_attr_group, | |
951 | NULL | |
16ffadfc | 952 | }; |
b119dc3f | 953 | |
0826374b | 954 | struct device_type i2c_adapter_type = { |
4f8cf824 JD |
955 | .groups = i2c_adapter_attr_groups, |
956 | .release = i2c_adapter_dev_release, | |
1da177e4 | 957 | }; |
0826374b | 958 | EXPORT_SYMBOL_GPL(i2c_adapter_type); |
1da177e4 | 959 | |
643dd09e SW |
960 | /** |
961 | * i2c_verify_adapter - return parameter as i2c_adapter or NULL | |
962 | * @dev: device, probably from some driver model iterator | |
963 | * | |
964 | * When traversing the driver model tree, perhaps using driver model | |
965 | * iterators like @device_for_each_child(), you can't assume very much | |
966 | * about the nodes you find. Use this function to avoid oopses caused | |
967 | * by wrongly treating some non-I2C device as an i2c_adapter. | |
968 | */ | |
969 | struct i2c_adapter *i2c_verify_adapter(struct device *dev) | |
970 | { | |
971 | return (dev->type == &i2c_adapter_type) | |
972 | ? to_i2c_adapter(dev) | |
973 | : NULL; | |
974 | } | |
975 | EXPORT_SYMBOL(i2c_verify_adapter); | |
976 | ||
2bb5095a JD |
977 | #ifdef CONFIG_I2C_COMPAT |
978 | static struct class_compat *i2c_adapter_compat_class; | |
979 | #endif | |
980 | ||
9c1600ed DB |
981 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
982 | { | |
983 | struct i2c_devinfo *devinfo; | |
984 | ||
f18c41da | 985 | down_read(&__i2c_board_lock); |
9c1600ed DB |
986 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
987 | if (devinfo->busnum == adapter->nr | |
988 | && !i2c_new_device(adapter, | |
989 | &devinfo->board_info)) | |
09b8ce0a ZX |
990 | dev_err(&adapter->dev, |
991 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
992 | devinfo->board_info.addr); |
993 | } | |
f18c41da | 994 | up_read(&__i2c_board_lock); |
9c1600ed DB |
995 | } |
996 | ||
687b81d0 WS |
997 | /* OF support code */ |
998 | ||
999 | #if IS_ENABLED(CONFIG_OF) | |
1000 | static void of_i2c_register_devices(struct i2c_adapter *adap) | |
1001 | { | |
1002 | void *result; | |
1003 | struct device_node *node; | |
1004 | ||
1005 | /* Only register child devices if the adapter has a node pointer set */ | |
1006 | if (!adap->dev.of_node) | |
1007 | return; | |
1008 | ||
1009 | dev_dbg(&adap->dev, "of_i2c: walking child nodes\n"); | |
1010 | ||
1011 | for_each_available_child_of_node(adap->dev.of_node, node) { | |
1012 | struct i2c_board_info info = {}; | |
1013 | struct dev_archdata dev_ad = {}; | |
1014 | const __be32 *addr; | |
1015 | int len; | |
1016 | ||
1017 | dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name); | |
1018 | ||
1019 | if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) { | |
1020 | dev_err(&adap->dev, "of_i2c: modalias failure on %s\n", | |
1021 | node->full_name); | |
1022 | continue; | |
1023 | } | |
1024 | ||
1025 | addr = of_get_property(node, "reg", &len); | |
1026 | if (!addr || (len < sizeof(int))) { | |
1027 | dev_err(&adap->dev, "of_i2c: invalid reg on %s\n", | |
1028 | node->full_name); | |
1029 | continue; | |
1030 | } | |
1031 | ||
1032 | info.addr = be32_to_cpup(addr); | |
1033 | if (info.addr > (1 << 10) - 1) { | |
1034 | dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n", | |
1035 | info.addr, node->full_name); | |
1036 | continue; | |
1037 | } | |
1038 | ||
1039 | info.irq = irq_of_parse_and_map(node, 0); | |
1040 | info.of_node = of_node_get(node); | |
1041 | info.archdata = &dev_ad; | |
1042 | ||
1043 | if (of_get_property(node, "wakeup-source", NULL)) | |
1044 | info.flags |= I2C_CLIENT_WAKE; | |
1045 | ||
1046 | request_module("%s%s", I2C_MODULE_PREFIX, info.type); | |
1047 | ||
1048 | result = i2c_new_device(adap, &info); | |
1049 | if (result == NULL) { | |
1050 | dev_err(&adap->dev, "of_i2c: Failure registering %s\n", | |
1051 | node->full_name); | |
1052 | of_node_put(node); | |
1053 | irq_dispose_mapping(info.irq); | |
1054 | continue; | |
1055 | } | |
1056 | } | |
1057 | } | |
1058 | ||
1059 | static int of_dev_node_match(struct device *dev, void *data) | |
1060 | { | |
1061 | return dev->of_node == data; | |
1062 | } | |
1063 | ||
1064 | /* must call put_device() when done with returned i2c_client device */ | |
1065 | struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) | |
1066 | { | |
1067 | struct device *dev; | |
1068 | ||
1069 | dev = bus_find_device(&i2c_bus_type, NULL, node, | |
1070 | of_dev_node_match); | |
1071 | if (!dev) | |
1072 | return NULL; | |
1073 | ||
1074 | return i2c_verify_client(dev); | |
1075 | } | |
1076 | EXPORT_SYMBOL(of_find_i2c_device_by_node); | |
1077 | ||
1078 | /* must call put_device() when done with returned i2c_adapter device */ | |
1079 | struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) | |
1080 | { | |
1081 | struct device *dev; | |
1082 | ||
1083 | dev = bus_find_device(&i2c_bus_type, NULL, node, | |
1084 | of_dev_node_match); | |
1085 | if (!dev) | |
1086 | return NULL; | |
1087 | ||
1088 | return i2c_verify_adapter(dev); | |
1089 | } | |
1090 | EXPORT_SYMBOL(of_find_i2c_adapter_by_node); | |
1091 | #else | |
1092 | static void of_i2c_register_devices(struct i2c_adapter *adap) { } | |
1093 | #endif /* CONFIG_OF */ | |
1094 | ||
69b0089a JD |
1095 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
1096 | struct i2c_adapter *adap) | |
026526f5 | 1097 | { |
4735c98f JD |
1098 | /* Detect supported devices on that bus, and instantiate them */ |
1099 | i2c_detect(adap, driver); | |
1100 | ||
1101 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 | 1102 | if (driver->attach_adapter) { |
a920ff41 JD |
1103 | dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n", |
1104 | driver->driver.name); | |
fe6fc258 JD |
1105 | dev_warn(&adap->dev, "Please use another way to instantiate " |
1106 | "your i2c_client\n"); | |
026526f5 JD |
1107 | /* We ignore the return code; if it fails, too bad */ |
1108 | driver->attach_adapter(adap); | |
1109 | } | |
1110 | return 0; | |
1111 | } | |
1112 | ||
69b0089a JD |
1113 | static int __process_new_adapter(struct device_driver *d, void *data) |
1114 | { | |
1115 | return i2c_do_add_adapter(to_i2c_driver(d), data); | |
1116 | } | |
1117 | ||
6e13e641 | 1118 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 1119 | { |
d6703281 | 1120 | int res = 0; |
1da177e4 | 1121 | |
1d0b19c9 | 1122 | /* Can't register until after driver model init */ |
35fc37f8 JD |
1123 | if (unlikely(WARN_ON(!i2c_bus_type.p))) { |
1124 | res = -EAGAIN; | |
1125 | goto out_list; | |
1126 | } | |
1d0b19c9 | 1127 | |
2236baa7 JD |
1128 | /* Sanity checks */ |
1129 | if (unlikely(adap->name[0] == '\0')) { | |
1130 | pr_err("i2c-core: Attempt to register an adapter with " | |
1131 | "no name!\n"); | |
1132 | return -EINVAL; | |
1133 | } | |
1134 | if (unlikely(!adap->algo)) { | |
1135 | pr_err("i2c-core: Attempt to register adapter '%s' with " | |
1136 | "no algo!\n", adap->name); | |
1137 | return -EINVAL; | |
1138 | } | |
1139 | ||
194684e5 | 1140 | rt_mutex_init(&adap->bus_lock); |
dafc50d1 | 1141 | mutex_init(&adap->userspace_clients_lock); |
6629dcff | 1142 | INIT_LIST_HEAD(&adap->userspace_clients); |
1da177e4 | 1143 | |
8fcfef6e JD |
1144 | /* Set default timeout to 1 second if not already set */ |
1145 | if (adap->timeout == 0) | |
1146 | adap->timeout = HZ; | |
1147 | ||
27d9c183 | 1148 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
1149 | adap->dev.bus = &i2c_bus_type; |
1150 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 JD |
1151 | res = device_register(&adap->dev); |
1152 | if (res) | |
1153 | goto out_list; | |
1da177e4 | 1154 | |
b6d7b3d1 JD |
1155 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
1156 | ||
2bb5095a JD |
1157 | #ifdef CONFIG_I2C_COMPAT |
1158 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
1159 | adap->dev.parent); | |
1160 | if (res) | |
1161 | dev_warn(&adap->dev, | |
1162 | "Failed to create compatibility class link\n"); | |
1163 | #endif | |
1164 | ||
5f9296ba VK |
1165 | /* bus recovery specific initialization */ |
1166 | if (adap->bus_recovery_info) { | |
1167 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
1168 | ||
1169 | if (!bri->recover_bus) { | |
1170 | dev_err(&adap->dev, "No recover_bus() found, not using recovery\n"); | |
1171 | adap->bus_recovery_info = NULL; | |
1172 | goto exit_recovery; | |
1173 | } | |
1174 | ||
1175 | /* Generic GPIO recovery */ | |
1176 | if (bri->recover_bus == i2c_generic_gpio_recovery) { | |
1177 | if (!gpio_is_valid(bri->scl_gpio)) { | |
1178 | dev_err(&adap->dev, "Invalid SCL gpio, not using recovery\n"); | |
1179 | adap->bus_recovery_info = NULL; | |
1180 | goto exit_recovery; | |
1181 | } | |
1182 | ||
1183 | if (gpio_is_valid(bri->sda_gpio)) | |
1184 | bri->get_sda = get_sda_gpio_value; | |
1185 | else | |
1186 | bri->get_sda = NULL; | |
1187 | ||
1188 | bri->get_scl = get_scl_gpio_value; | |
1189 | bri->set_scl = set_scl_gpio_value; | |
1190 | } else if (!bri->set_scl || !bri->get_scl) { | |
1191 | /* Generic SCL recovery */ | |
1192 | dev_err(&adap->dev, "No {get|set}_gpio() found, not using recovery\n"); | |
1193 | adap->bus_recovery_info = NULL; | |
1194 | } | |
1195 | } | |
1196 | ||
1197 | exit_recovery: | |
729d6dd5 | 1198 | /* create pre-declared device nodes */ |
687b81d0 | 1199 | of_i2c_register_devices(adap); |
55e71edb | 1200 | acpi_i2c_register_devices(adap); |
5d98e61d | 1201 | acpi_i2c_install_space_handler(adap); |
687b81d0 | 1202 | |
6e13e641 DB |
1203 | if (adap->nr < __i2c_first_dynamic_bus_num) |
1204 | i2c_scan_static_board_info(adap); | |
1205 | ||
4735c98f | 1206 | /* Notify drivers */ |
35fc37f8 | 1207 | mutex_lock(&core_lock); |
d6703281 | 1208 | bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); |
caada32a | 1209 | mutex_unlock(&core_lock); |
35fc37f8 JD |
1210 | |
1211 | return 0; | |
b119c6c9 | 1212 | |
b119c6c9 | 1213 | out_list: |
35fc37f8 | 1214 | mutex_lock(&core_lock); |
b119c6c9 | 1215 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
1216 | mutex_unlock(&core_lock); |
1217 | return res; | |
1da177e4 LT |
1218 | } |
1219 | ||
ee5c2744 DA |
1220 | /** |
1221 | * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 | |
1222 | * @adap: the adapter to register (with adap->nr initialized) | |
1223 | * Context: can sleep | |
1224 | * | |
1225 | * See i2c_add_numbered_adapter() for details. | |
1226 | */ | |
1227 | static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1228 | { | |
1229 | int id; | |
1230 | ||
1231 | mutex_lock(&core_lock); | |
1232 | id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, | |
1233 | GFP_KERNEL); | |
1234 | mutex_unlock(&core_lock); | |
1235 | if (id < 0) | |
1236 | return id == -ENOSPC ? -EBUSY : id; | |
1237 | ||
1238 | return i2c_register_adapter(adap); | |
1239 | } | |
1240 | ||
6e13e641 DB |
1241 | /** |
1242 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
1243 | * @adapter: the adapter to add | |
d64f73be | 1244 | * Context: can sleep |
6e13e641 DB |
1245 | * |
1246 | * This routine is used to declare an I2C adapter when its bus number | |
ee5c2744 DA |
1247 | * doesn't matter or when its bus number is specified by an dt alias. |
1248 | * Examples of bases when the bus number doesn't matter: I2C adapters | |
1249 | * dynamically added by USB links or PCI plugin cards. | |
6e13e641 DB |
1250 | * |
1251 | * When this returns zero, a new bus number was allocated and stored | |
1252 | * in adap->nr, and the specified adapter became available for clients. | |
1253 | * Otherwise, a negative errno value is returned. | |
1254 | */ | |
1255 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
1256 | { | |
ee5c2744 | 1257 | struct device *dev = &adapter->dev; |
4ae42b0f | 1258 | int id; |
6e13e641 | 1259 | |
ee5c2744 DA |
1260 | if (dev->of_node) { |
1261 | id = of_alias_get_id(dev->of_node, "i2c"); | |
1262 | if (id >= 0) { | |
1263 | adapter->nr = id; | |
1264 | return __i2c_add_numbered_adapter(adapter); | |
1265 | } | |
1266 | } | |
1267 | ||
caada32a | 1268 | mutex_lock(&core_lock); |
4ae42b0f TH |
1269 | id = idr_alloc(&i2c_adapter_idr, adapter, |
1270 | __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); | |
caada32a | 1271 | mutex_unlock(&core_lock); |
4ae42b0f TH |
1272 | if (id < 0) |
1273 | return id; | |
6e13e641 DB |
1274 | |
1275 | adapter->nr = id; | |
4ae42b0f | 1276 | |
6e13e641 DB |
1277 | return i2c_register_adapter(adapter); |
1278 | } | |
1279 | EXPORT_SYMBOL(i2c_add_adapter); | |
1280 | ||
1281 | /** | |
1282 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
1283 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 1284 | * Context: can sleep |
6e13e641 DB |
1285 | * |
1286 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
1287 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
1288 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
1289 | * is used to properly configure I2C devices. |
1290 | * | |
488bf314 GL |
1291 | * If the requested bus number is set to -1, then this function will behave |
1292 | * identically to i2c_add_adapter, and will dynamically assign a bus number. | |
1293 | * | |
6e13e641 DB |
1294 | * If no devices have pre-been declared for this bus, then be sure to |
1295 | * register the adapter before any dynamically allocated ones. Otherwise | |
1296 | * the required bus ID may not be available. | |
1297 | * | |
1298 | * When this returns zero, the specified adapter became available for | |
1299 | * clients using the bus number provided in adap->nr. Also, the table | |
1300 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
1301 | * and the appropriate driver model device nodes are created. Otherwise, a | |
1302 | * negative errno value is returned. | |
1303 | */ | |
1304 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1305 | { | |
488bf314 GL |
1306 | if (adap->nr == -1) /* -1 means dynamically assign bus id */ |
1307 | return i2c_add_adapter(adap); | |
6e13e641 | 1308 | |
ee5c2744 | 1309 | return __i2c_add_numbered_adapter(adap); |
6e13e641 DB |
1310 | } |
1311 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
1312 | ||
19baba4c | 1313 | static void i2c_do_del_adapter(struct i2c_driver *driver, |
69b0089a | 1314 | struct i2c_adapter *adapter) |
026526f5 | 1315 | { |
4735c98f | 1316 | struct i2c_client *client, *_n; |
026526f5 | 1317 | |
acec211c JD |
1318 | /* Remove the devices we created ourselves as the result of hardware |
1319 | * probing (using a driver's detect method) */ | |
4735c98f JD |
1320 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
1321 | if (client->adapter == adapter) { | |
1322 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
1323 | client->name, client->addr); | |
1324 | list_del(&client->detected); | |
1325 | i2c_unregister_device(client); | |
1326 | } | |
1327 | } | |
026526f5 JD |
1328 | } |
1329 | ||
e549c2b5 | 1330 | static int __unregister_client(struct device *dev, void *dummy) |
5219bf88 JD |
1331 | { |
1332 | struct i2c_client *client = i2c_verify_client(dev); | |
1333 | if (client && strcmp(client->name, "dummy")) | |
1334 | i2c_unregister_device(client); | |
1335 | return 0; | |
1336 | } | |
1337 | ||
1338 | static int __unregister_dummy(struct device *dev, void *dummy) | |
e549c2b5 JD |
1339 | { |
1340 | struct i2c_client *client = i2c_verify_client(dev); | |
1341 | if (client) | |
1342 | i2c_unregister_device(client); | |
1343 | return 0; | |
1344 | } | |
1345 | ||
69b0089a JD |
1346 | static int __process_removed_adapter(struct device_driver *d, void *data) |
1347 | { | |
19baba4c LPC |
1348 | i2c_do_del_adapter(to_i2c_driver(d), data); |
1349 | return 0; | |
69b0089a JD |
1350 | } |
1351 | ||
d64f73be DB |
1352 | /** |
1353 | * i2c_del_adapter - unregister I2C adapter | |
1354 | * @adap: the adapter being unregistered | |
1355 | * Context: can sleep | |
1356 | * | |
1357 | * This unregisters an I2C adapter which was previously registered | |
1358 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
1359 | */ | |
71546300 | 1360 | void i2c_del_adapter(struct i2c_adapter *adap) |
1da177e4 | 1361 | { |
35fc37f8 | 1362 | struct i2c_adapter *found; |
bbd2d9c9 | 1363 | struct i2c_client *client, *next; |
1da177e4 LT |
1364 | |
1365 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
1366 | mutex_lock(&core_lock); |
1367 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
1368 | mutex_unlock(&core_lock); | |
1369 | if (found != adap) { | |
b6d7b3d1 JD |
1370 | pr_debug("i2c-core: attempting to delete unregistered " |
1371 | "adapter [%s]\n", adap->name); | |
71546300 | 1372 | return; |
1da177e4 LT |
1373 | } |
1374 | ||
5d98e61d | 1375 | acpi_i2c_remove_space_handler(adap); |
026526f5 | 1376 | /* Tell drivers about this removal */ |
35fc37f8 | 1377 | mutex_lock(&core_lock); |
19baba4c | 1378 | bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 1379 | __process_removed_adapter); |
35fc37f8 | 1380 | mutex_unlock(&core_lock); |
1da177e4 | 1381 | |
bbd2d9c9 | 1382 | /* Remove devices instantiated from sysfs */ |
390946b1 JD |
1383 | mutex_lock_nested(&adap->userspace_clients_lock, |
1384 | i2c_adapter_depth(adap)); | |
6629dcff JD |
1385 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1386 | detected) { | |
1387 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, | |
1388 | client->addr); | |
1389 | list_del(&client->detected); | |
1390 | i2c_unregister_device(client); | |
bbd2d9c9 | 1391 | } |
dafc50d1 | 1392 | mutex_unlock(&adap->userspace_clients_lock); |
bbd2d9c9 | 1393 | |
e549c2b5 | 1394 | /* Detach any active clients. This can't fail, thus we do not |
5219bf88 JD |
1395 | * check the returned value. This is a two-pass process, because |
1396 | * we can't remove the dummy devices during the first pass: they | |
1397 | * could have been instantiated by real devices wishing to clean | |
1398 | * them up properly, so we give them a chance to do that first. */ | |
19baba4c LPC |
1399 | device_for_each_child(&adap->dev, NULL, __unregister_client); |
1400 | device_for_each_child(&adap->dev, NULL, __unregister_dummy); | |
1da177e4 | 1401 | |
2bb5095a JD |
1402 | #ifdef CONFIG_I2C_COMPAT |
1403 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
1404 | adap->dev.parent); | |
1405 | #endif | |
1406 | ||
c5567521 TLSC |
1407 | /* device name is gone after device_unregister */ |
1408 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); | |
1409 | ||
1da177e4 LT |
1410 | /* clean up the sysfs representation */ |
1411 | init_completion(&adap->dev_released); | |
1da177e4 | 1412 | device_unregister(&adap->dev); |
1da177e4 LT |
1413 | |
1414 | /* wait for sysfs to drop all references */ | |
1415 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 1416 | |
6e13e641 | 1417 | /* free bus id */ |
35fc37f8 | 1418 | mutex_lock(&core_lock); |
1da177e4 | 1419 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 1420 | mutex_unlock(&core_lock); |
1da177e4 | 1421 | |
bd4bc3db JD |
1422 | /* Clear the device structure in case this adapter is ever going to be |
1423 | added again */ | |
1424 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
1da177e4 | 1425 | } |
c0564606 | 1426 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 | 1427 | |
7b4fbc50 DB |
1428 | /* ------------------------------------------------------------------------- */ |
1429 | ||
7ae31482 JD |
1430 | int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) |
1431 | { | |
1432 | int res; | |
1433 | ||
1434 | mutex_lock(&core_lock); | |
1435 | res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); | |
1436 | mutex_unlock(&core_lock); | |
1437 | ||
1438 | return res; | |
1439 | } | |
1440 | EXPORT_SYMBOL_GPL(i2c_for_each_dev); | |
1441 | ||
69b0089a | 1442 | static int __process_new_driver(struct device *dev, void *data) |
7f101a97 | 1443 | { |
4f8cf824 JD |
1444 | if (dev->type != &i2c_adapter_type) |
1445 | return 0; | |
69b0089a | 1446 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
7f101a97 DY |
1447 | } |
1448 | ||
7b4fbc50 DB |
1449 | /* |
1450 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 1451 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
1452 | */ |
1453 | ||
de59cf9e | 1454 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 1455 | { |
7eebcb7c | 1456 | int res; |
1da177e4 | 1457 | |
1d0b19c9 DB |
1458 | /* Can't register until after driver model init */ |
1459 | if (unlikely(WARN_ON(!i2c_bus_type.p))) | |
1460 | return -EAGAIN; | |
1461 | ||
1da177e4 | 1462 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 1463 | driver->driver.owner = owner; |
1da177e4 | 1464 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 1465 | |
729d6dd5 | 1466 | /* When registration returns, the driver core |
6e13e641 DB |
1467 | * will have called probe() for all matching-but-unbound devices. |
1468 | */ | |
1da177e4 LT |
1469 | res = driver_register(&driver->driver); |
1470 | if (res) | |
7eebcb7c | 1471 | return res; |
438d6c2c | 1472 | |
f4e8db31 MB |
1473 | /* Drivers should switch to dev_pm_ops instead. */ |
1474 | if (driver->suspend) | |
1475 | pr_warn("i2c-core: driver [%s] using legacy suspend method\n", | |
1476 | driver->driver.name); | |
1477 | if (driver->resume) | |
1478 | pr_warn("i2c-core: driver [%s] using legacy resume method\n", | |
1479 | driver->driver.name); | |
1480 | ||
35d8b2e6 | 1481 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 1482 | |
4735c98f JD |
1483 | INIT_LIST_HEAD(&driver->clients); |
1484 | /* Walk the adapters that are already present */ | |
7ae31482 | 1485 | i2c_for_each_dev(driver, __process_new_driver); |
35fc37f8 | 1486 | |
7f101a97 DY |
1487 | return 0; |
1488 | } | |
1489 | EXPORT_SYMBOL(i2c_register_driver); | |
1490 | ||
69b0089a | 1491 | static int __process_removed_driver(struct device *dev, void *data) |
7f101a97 | 1492 | { |
19baba4c LPC |
1493 | if (dev->type == &i2c_adapter_type) |
1494 | i2c_do_del_adapter(data, to_i2c_adapter(dev)); | |
1495 | return 0; | |
1da177e4 LT |
1496 | } |
1497 | ||
a1d9e6e4 DB |
1498 | /** |
1499 | * i2c_del_driver - unregister I2C driver | |
1500 | * @driver: the driver being unregistered | |
d64f73be | 1501 | * Context: can sleep |
a1d9e6e4 | 1502 | */ |
b3e82096 | 1503 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 1504 | { |
7ae31482 | 1505 | i2c_for_each_dev(driver, __process_removed_driver); |
1da177e4 LT |
1506 | |
1507 | driver_unregister(&driver->driver); | |
35d8b2e6 | 1508 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 1509 | } |
c0564606 | 1510 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 1511 | |
7b4fbc50 DB |
1512 | /* ------------------------------------------------------------------------- */ |
1513 | ||
e48d3319 JD |
1514 | /** |
1515 | * i2c_use_client - increments the reference count of the i2c client structure | |
1516 | * @client: the client being referenced | |
1517 | * | |
1518 | * Each live reference to a client should be refcounted. The driver model does | |
1519 | * that automatically as part of driver binding, so that most drivers don't | |
1520 | * need to do this explicitly: they hold a reference until they're unbound | |
1521 | * from the device. | |
1522 | * | |
1523 | * A pointer to the client with the incremented reference counter is returned. | |
1524 | */ | |
1525 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 1526 | { |
6ea438ec DB |
1527 | if (client && get_device(&client->dev)) |
1528 | return client; | |
1529 | return NULL; | |
1da177e4 | 1530 | } |
c0564606 | 1531 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 1532 | |
e48d3319 JD |
1533 | /** |
1534 | * i2c_release_client - release a use of the i2c client structure | |
1535 | * @client: the client being no longer referenced | |
1536 | * | |
1537 | * Must be called when a user of a client is finished with it. | |
1538 | */ | |
1539 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 1540 | { |
6ea438ec DB |
1541 | if (client) |
1542 | put_device(&client->dev); | |
1da177e4 | 1543 | } |
c0564606 | 1544 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 1545 | |
9b766b81 DB |
1546 | struct i2c_cmd_arg { |
1547 | unsigned cmd; | |
1548 | void *arg; | |
1549 | }; | |
1550 | ||
1551 | static int i2c_cmd(struct device *dev, void *_arg) | |
1552 | { | |
1553 | struct i2c_client *client = i2c_verify_client(dev); | |
1554 | struct i2c_cmd_arg *arg = _arg; | |
0acc2b32 LPC |
1555 | struct i2c_driver *driver; |
1556 | ||
1557 | if (!client || !client->dev.driver) | |
1558 | return 0; | |
9b766b81 | 1559 | |
0acc2b32 LPC |
1560 | driver = to_i2c_driver(client->dev.driver); |
1561 | if (driver->command) | |
1562 | driver->command(client, arg->cmd, arg->arg); | |
9b766b81 DB |
1563 | return 0; |
1564 | } | |
1565 | ||
1da177e4 LT |
1566 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
1567 | { | |
9b766b81 | 1568 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 1569 | |
9b766b81 DB |
1570 | cmd_arg.cmd = cmd; |
1571 | cmd_arg.arg = arg; | |
1572 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 1573 | } |
c0564606 | 1574 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
1575 | |
1576 | static int __init i2c_init(void) | |
1577 | { | |
1578 | int retval; | |
1579 | ||
1580 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
1581 | if (retval) |
1582 | return retval; | |
2bb5095a JD |
1583 | #ifdef CONFIG_I2C_COMPAT |
1584 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
1585 | if (!i2c_adapter_compat_class) { | |
1586 | retval = -ENOMEM; | |
1587 | goto bus_err; | |
1588 | } | |
1589 | #endif | |
e9f1373b DB |
1590 | retval = i2c_add_driver(&dummy_driver); |
1591 | if (retval) | |
2bb5095a | 1592 | goto class_err; |
e9f1373b DB |
1593 | return 0; |
1594 | ||
2bb5095a JD |
1595 | class_err: |
1596 | #ifdef CONFIG_I2C_COMPAT | |
1597 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 1598 | bus_err: |
2bb5095a | 1599 | #endif |
e9f1373b DB |
1600 | bus_unregister(&i2c_bus_type); |
1601 | return retval; | |
1da177e4 LT |
1602 | } |
1603 | ||
1604 | static void __exit i2c_exit(void) | |
1605 | { | |
e9f1373b | 1606 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
1607 | #ifdef CONFIG_I2C_COMPAT |
1608 | class_compat_unregister(i2c_adapter_compat_class); | |
1609 | #endif | |
1da177e4 | 1610 | bus_unregister(&i2c_bus_type); |
d9a83d62 | 1611 | tracepoint_synchronize_unregister(); |
1da177e4 LT |
1612 | } |
1613 | ||
a10f9e7c DB |
1614 | /* We must initialize early, because some subsystems register i2c drivers |
1615 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1616 | */ | |
1617 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1618 | module_exit(i2c_exit); |
1619 | ||
1620 | /* ---------------------------------------------------- | |
1621 | * the functional interface to the i2c busses. | |
1622 | * ---------------------------------------------------- | |
1623 | */ | |
1624 | ||
b37d2a3a JD |
1625 | /** |
1626 | * __i2c_transfer - unlocked flavor of i2c_transfer | |
1627 | * @adap: Handle to I2C bus | |
1628 | * @msgs: One or more messages to execute before STOP is issued to | |
1629 | * terminate the operation; each message begins with a START. | |
1630 | * @num: Number of messages to be executed. | |
1631 | * | |
1632 | * Returns negative errno, else the number of messages executed. | |
1633 | * | |
1634 | * Adapter lock must be held when calling this function. No debug logging | |
1635 | * takes place. adap->algo->master_xfer existence isn't checked. | |
1636 | */ | |
1637 | int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
1638 | { | |
1639 | unsigned long orig_jiffies; | |
1640 | int ret, try; | |
1641 | ||
d9a83d62 DH |
1642 | /* i2c_trace_msg gets enabled when tracepoint i2c_transfer gets |
1643 | * enabled. This is an efficient way of keeping the for-loop from | |
1644 | * being executed when not needed. | |
1645 | */ | |
1646 | if (static_key_false(&i2c_trace_msg)) { | |
1647 | int i; | |
1648 | for (i = 0; i < num; i++) | |
1649 | if (msgs[i].flags & I2C_M_RD) | |
1650 | trace_i2c_read(adap, &msgs[i], i); | |
1651 | else | |
1652 | trace_i2c_write(adap, &msgs[i], i); | |
1653 | } | |
1654 | ||
b37d2a3a JD |
1655 | /* Retry automatically on arbitration loss */ |
1656 | orig_jiffies = jiffies; | |
1657 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
1658 | ret = adap->algo->master_xfer(adap, msgs, num); | |
1659 | if (ret != -EAGAIN) | |
1660 | break; | |
1661 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
1662 | break; | |
1663 | } | |
1664 | ||
d9a83d62 DH |
1665 | if (static_key_false(&i2c_trace_msg)) { |
1666 | int i; | |
1667 | for (i = 0; i < ret; i++) | |
1668 | if (msgs[i].flags & I2C_M_RD) | |
1669 | trace_i2c_reply(adap, &msgs[i], i); | |
1670 | trace_i2c_result(adap, i, ret); | |
1671 | } | |
1672 | ||
b37d2a3a JD |
1673 | return ret; |
1674 | } | |
1675 | EXPORT_SYMBOL(__i2c_transfer); | |
1676 | ||
a1cdedac DB |
1677 | /** |
1678 | * i2c_transfer - execute a single or combined I2C message | |
1679 | * @adap: Handle to I2C bus | |
1680 | * @msgs: One or more messages to execute before STOP is issued to | |
1681 | * terminate the operation; each message begins with a START. | |
1682 | * @num: Number of messages to be executed. | |
1683 | * | |
1684 | * Returns negative errno, else the number of messages executed. | |
1685 | * | |
1686 | * Note that there is no requirement that each message be sent to | |
1687 | * the same slave address, although that is the most common model. | |
1688 | */ | |
09b8ce0a | 1689 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 1690 | { |
b37d2a3a | 1691 | int ret; |
1da177e4 | 1692 | |
a1cdedac DB |
1693 | /* REVISIT the fault reporting model here is weak: |
1694 | * | |
1695 | * - When we get an error after receiving N bytes from a slave, | |
1696 | * there is no way to report "N". | |
1697 | * | |
1698 | * - When we get a NAK after transmitting N bytes to a slave, | |
1699 | * there is no way to report "N" ... or to let the master | |
1700 | * continue executing the rest of this combined message, if | |
1701 | * that's the appropriate response. | |
1702 | * | |
1703 | * - When for example "num" is two and we successfully complete | |
1704 | * the first message but get an error part way through the | |
1705 | * second, it's unclear whether that should be reported as | |
1706 | * one (discarding status on the second message) or errno | |
1707 | * (discarding status on the first one). | |
1708 | */ | |
1709 | ||
1da177e4 LT |
1710 | if (adap->algo->master_xfer) { |
1711 | #ifdef DEBUG | |
1712 | for (ret = 0; ret < num; ret++) { | |
1713 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
1714 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
1715 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
1716 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
1717 | } |
1718 | #endif | |
1719 | ||
cea443a8 | 1720 | if (in_atomic() || irqs_disabled()) { |
fe61e07e | 1721 | ret = i2c_trylock_adapter(adap); |
cea443a8 MR |
1722 | if (!ret) |
1723 | /* I2C activity is ongoing. */ | |
1724 | return -EAGAIN; | |
1725 | } else { | |
fe61e07e | 1726 | i2c_lock_adapter(adap); |
cea443a8 MR |
1727 | } |
1728 | ||
b37d2a3a | 1729 | ret = __i2c_transfer(adap, msgs, num); |
fe61e07e | 1730 | i2c_unlock_adapter(adap); |
1da177e4 LT |
1731 | |
1732 | return ret; | |
1733 | } else { | |
1734 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1735 | return -EOPNOTSUPP; |
1da177e4 LT |
1736 | } |
1737 | } | |
c0564606 | 1738 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1739 | |
a1cdedac DB |
1740 | /** |
1741 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1742 | * @client: Handle to slave device | |
1743 | * @buf: Data that will be written to the slave | |
0c43ea54 | 1744 | * @count: How many bytes to write, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1745 | * |
1746 | * Returns negative errno, or else the number of bytes written. | |
1747 | */ | |
0cc43a18 | 1748 | int i2c_master_send(const struct i2c_client *client, const char *buf, int count) |
1da177e4 LT |
1749 | { |
1750 | int ret; | |
7225acf4 | 1751 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1752 | struct i2c_msg msg; |
1753 | ||
815f55f2 JD |
1754 | msg.addr = client->addr; |
1755 | msg.flags = client->flags & I2C_M_TEN; | |
1756 | msg.len = count; | |
1757 | msg.buf = (char *)buf; | |
438d6c2c | 1758 | |
815f55f2 | 1759 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1760 | |
834aa6f3 WS |
1761 | /* |
1762 | * If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1763 | * transmitted, else error code. | |
1764 | */ | |
815f55f2 | 1765 | return (ret == 1) ? count : ret; |
1da177e4 | 1766 | } |
c0564606 | 1767 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1768 | |
a1cdedac DB |
1769 | /** |
1770 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1771 | * @client: Handle to slave device | |
1772 | * @buf: Where to store data read from slave | |
0c43ea54 | 1773 | * @count: How many bytes to read, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1774 | * |
1775 | * Returns negative errno, or else the number of bytes read. | |
1776 | */ | |
0cc43a18 | 1777 | int i2c_master_recv(const struct i2c_client *client, char *buf, int count) |
1da177e4 | 1778 | { |
7225acf4 | 1779 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1780 | struct i2c_msg msg; |
1781 | int ret; | |
815f55f2 JD |
1782 | |
1783 | msg.addr = client->addr; | |
1784 | msg.flags = client->flags & I2C_M_TEN; | |
1785 | msg.flags |= I2C_M_RD; | |
1786 | msg.len = count; | |
1787 | msg.buf = buf; | |
1788 | ||
1789 | ret = i2c_transfer(adap, &msg, 1); | |
1790 | ||
834aa6f3 WS |
1791 | /* |
1792 | * If everything went ok (i.e. 1 msg received), return #bytes received, | |
1793 | * else error code. | |
1794 | */ | |
815f55f2 | 1795 | return (ret == 1) ? count : ret; |
1da177e4 | 1796 | } |
c0564606 | 1797 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1798 | |
1da177e4 LT |
1799 | /* ---------------------------------------------------- |
1800 | * the i2c address scanning function | |
1801 | * Will not work for 10-bit addresses! | |
1802 | * ---------------------------------------------------- | |
1803 | */ | |
1da177e4 | 1804 | |
63e4e802 JD |
1805 | /* |
1806 | * Legacy default probe function, mostly relevant for SMBus. The default | |
1807 | * probe method is a quick write, but it is known to corrupt the 24RF08 | |
1808 | * EEPROMs due to a state machine bug, and could also irreversibly | |
1809 | * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, | |
1810 | * we use a short byte read instead. Also, some bus drivers don't implement | |
1811 | * quick write, so we fallback to a byte read in that case too. | |
1812 | * On x86, there is another special case for FSC hardware monitoring chips, | |
1813 | * which want regular byte reads (address 0x73.) Fortunately, these are the | |
1814 | * only known chips using this I2C address on PC hardware. | |
1815 | * Returns 1 if probe succeeded, 0 if not. | |
1816 | */ | |
1817 | static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) | |
1818 | { | |
1819 | int err; | |
1820 | union i2c_smbus_data dummy; | |
1821 | ||
1822 | #ifdef CONFIG_X86 | |
1823 | if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) | |
1824 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) | |
1825 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1826 | I2C_SMBUS_BYTE_DATA, &dummy); | |
1827 | else | |
1828 | #endif | |
8031d79b JD |
1829 | if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) |
1830 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) | |
63e4e802 JD |
1831 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, |
1832 | I2C_SMBUS_QUICK, NULL); | |
8031d79b JD |
1833 | else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) |
1834 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1835 | I2C_SMBUS_BYTE, &dummy); | |
1836 | else { | |
d63a9e85 AL |
1837 | dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", |
1838 | addr); | |
8031d79b JD |
1839 | err = -EOPNOTSUPP; |
1840 | } | |
63e4e802 JD |
1841 | |
1842 | return err >= 0; | |
1843 | } | |
1844 | ||
ccfbbd08 | 1845 | static int i2c_detect_address(struct i2c_client *temp_client, |
4735c98f JD |
1846 | struct i2c_driver *driver) |
1847 | { | |
1848 | struct i2c_board_info info; | |
1849 | struct i2c_adapter *adapter = temp_client->adapter; | |
1850 | int addr = temp_client->addr; | |
1851 | int err; | |
1852 | ||
1853 | /* Make sure the address is valid */ | |
656b8761 JD |
1854 | err = i2c_check_addr_validity(addr); |
1855 | if (err) { | |
4735c98f JD |
1856 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
1857 | addr); | |
656b8761 | 1858 | return err; |
4735c98f JD |
1859 | } |
1860 | ||
1861 | /* Skip if already in use */ | |
3b5f794b | 1862 | if (i2c_check_addr_busy(adapter, addr)) |
4735c98f JD |
1863 | return 0; |
1864 | ||
ccfbbd08 | 1865 | /* Make sure there is something at this address */ |
63e4e802 JD |
1866 | if (!i2c_default_probe(adapter, addr)) |
1867 | return 0; | |
4735c98f JD |
1868 | |
1869 | /* Finally call the custom detection function */ | |
1870 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
1871 | info.addr = addr; | |
310ec792 | 1872 | err = driver->detect(temp_client, &info); |
4735c98f JD |
1873 | if (err) { |
1874 | /* -ENODEV is returned if the detection fails. We catch it | |
1875 | here as this isn't an error. */ | |
1876 | return err == -ENODEV ? 0 : err; | |
1877 | } | |
1878 | ||
1879 | /* Consistency check */ | |
1880 | if (info.type[0] == '\0') { | |
1881 | dev_err(&adapter->dev, "%s detection function provided " | |
1882 | "no name for 0x%x\n", driver->driver.name, | |
1883 | addr); | |
1884 | } else { | |
1885 | struct i2c_client *client; | |
1886 | ||
1887 | /* Detection succeeded, instantiate the device */ | |
0c176170 WS |
1888 | if (adapter->class & I2C_CLASS_DEPRECATED) |
1889 | dev_warn(&adapter->dev, | |
1890 | "This adapter will soon drop class based instantiation of devices. " | |
1891 | "Please make sure client 0x%02x gets instantiated by other means. " | |
1892 | "Check 'Documentation/i2c/instantiating-devices' for details.\n", | |
1893 | info.addr); | |
1894 | ||
4735c98f JD |
1895 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", |
1896 | info.type, info.addr); | |
1897 | client = i2c_new_device(adapter, &info); | |
1898 | if (client) | |
1899 | list_add_tail(&client->detected, &driver->clients); | |
1900 | else | |
1901 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
1902 | info.type, info.addr); | |
1903 | } | |
1904 | return 0; | |
1905 | } | |
1906 | ||
1907 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
1908 | { | |
c3813d6a | 1909 | const unsigned short *address_list; |
4735c98f JD |
1910 | struct i2c_client *temp_client; |
1911 | int i, err = 0; | |
1912 | int adap_id = i2c_adapter_id(adapter); | |
1913 | ||
c3813d6a JD |
1914 | address_list = driver->address_list; |
1915 | if (!driver->detect || !address_list) | |
4735c98f JD |
1916 | return 0; |
1917 | ||
51b54ba9 JD |
1918 | /* Stop here if the classes do not match */ |
1919 | if (!(adapter->class & driver->class)) | |
1920 | return 0; | |
1921 | ||
4735c98f JD |
1922 | /* Set up a temporary client to help detect callback */ |
1923 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
1924 | if (!temp_client) | |
1925 | return -ENOMEM; | |
1926 | temp_client->adapter = adapter; | |
1927 | ||
c3813d6a | 1928 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
4735c98f | 1929 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
c3813d6a JD |
1930 | "addr 0x%02x\n", adap_id, address_list[i]); |
1931 | temp_client->addr = address_list[i]; | |
ccfbbd08 | 1932 | err = i2c_detect_address(temp_client, driver); |
51b54ba9 JD |
1933 | if (unlikely(err)) |
1934 | break; | |
4735c98f JD |
1935 | } |
1936 | ||
4735c98f JD |
1937 | kfree(temp_client); |
1938 | return err; | |
1939 | } | |
1940 | ||
d44f19d5 JD |
1941 | int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) |
1942 | { | |
1943 | return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1944 | I2C_SMBUS_QUICK, NULL) >= 0; | |
1945 | } | |
1946 | EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); | |
1947 | ||
12b5053a JD |
1948 | struct i2c_client * |
1949 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1950 | struct i2c_board_info *info, | |
9a94241a JD |
1951 | unsigned short const *addr_list, |
1952 | int (*probe)(struct i2c_adapter *, unsigned short addr)) | |
12b5053a JD |
1953 | { |
1954 | int i; | |
1955 | ||
8031d79b | 1956 | if (!probe) |
9a94241a | 1957 | probe = i2c_default_probe; |
12b5053a | 1958 | |
12b5053a JD |
1959 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1960 | /* Check address validity */ | |
656b8761 | 1961 | if (i2c_check_addr_validity(addr_list[i]) < 0) { |
12b5053a JD |
1962 | dev_warn(&adap->dev, "Invalid 7-bit address " |
1963 | "0x%02x\n", addr_list[i]); | |
1964 | continue; | |
1965 | } | |
1966 | ||
1967 | /* Check address availability */ | |
3b5f794b | 1968 | if (i2c_check_addr_busy(adap, addr_list[i])) { |
12b5053a JD |
1969 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1970 | "use, not probing\n", addr_list[i]); | |
1971 | continue; | |
1972 | } | |
1973 | ||
63e4e802 | 1974 | /* Test address responsiveness */ |
9a94241a | 1975 | if (probe(adap, addr_list[i])) |
63e4e802 | 1976 | break; |
12b5053a | 1977 | } |
12b5053a JD |
1978 | |
1979 | if (addr_list[i] == I2C_CLIENT_END) { | |
1980 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1981 | return NULL; | |
1982 | } | |
1983 | ||
1984 | info->addr = addr_list[i]; | |
1985 | return i2c_new_device(adap, info); | |
1986 | } | |
1987 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
1988 | ||
d735b34d | 1989 | struct i2c_adapter *i2c_get_adapter(int nr) |
1da177e4 | 1990 | { |
1da177e4 | 1991 | struct i2c_adapter *adapter; |
438d6c2c | 1992 | |
caada32a | 1993 | mutex_lock(&core_lock); |
d735b34d | 1994 | adapter = idr_find(&i2c_adapter_idr, nr); |
a0920e10 MH |
1995 | if (adapter && !try_module_get(adapter->owner)) |
1996 | adapter = NULL; | |
1997 | ||
caada32a | 1998 | mutex_unlock(&core_lock); |
a0920e10 | 1999 | return adapter; |
1da177e4 | 2000 | } |
c0564606 | 2001 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
2002 | |
2003 | void i2c_put_adapter(struct i2c_adapter *adap) | |
2004 | { | |
c66c4cc0 SH |
2005 | if (adap) |
2006 | module_put(adap->owner); | |
1da177e4 | 2007 | } |
c0564606 | 2008 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
2009 | |
2010 | /* The SMBus parts */ | |
2011 | ||
438d6c2c | 2012 | #define POLY (0x1070U << 3) |
09b8ce0a | 2013 | static u8 crc8(u16 data) |
1da177e4 LT |
2014 | { |
2015 | int i; | |
438d6c2c | 2016 | |
7225acf4 | 2017 | for (i = 0; i < 8; i++) { |
438d6c2c | 2018 | if (data & 0x8000) |
1da177e4 LT |
2019 | data = data ^ POLY; |
2020 | data = data << 1; | |
2021 | } | |
2022 | return (u8)(data >> 8); | |
2023 | } | |
2024 | ||
421ef47b JD |
2025 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
2026 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
2027 | { |
2028 | int i; | |
2029 | ||
7225acf4 | 2030 | for (i = 0; i < count; i++) |
421ef47b | 2031 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
2032 | return crc; |
2033 | } | |
2034 | ||
421ef47b JD |
2035 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
2036 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 2037 | { |
421ef47b JD |
2038 | /* The address will be sent first */ |
2039 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
2040 | pec = i2c_smbus_pec(pec, &addr, 1); | |
2041 | ||
2042 | /* The data buffer follows */ | |
2043 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
2044 | } |
2045 | ||
421ef47b JD |
2046 | /* Used for write only transactions */ |
2047 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 2048 | { |
421ef47b JD |
2049 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
2050 | msg->len++; | |
1da177e4 LT |
2051 | } |
2052 | ||
421ef47b JD |
2053 | /* Return <0 on CRC error |
2054 | If there was a write before this read (most cases) we need to take the | |
2055 | partial CRC from the write part into account. | |
2056 | Note that this function does modify the message (we need to decrease the | |
2057 | message length to hide the CRC byte from the caller). */ | |
2058 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 2059 | { |
421ef47b JD |
2060 | u8 rpec = msg->buf[--msg->len]; |
2061 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 2062 | |
1da177e4 LT |
2063 | if (rpec != cpec) { |
2064 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
2065 | rpec, cpec); | |
24a5bb7b | 2066 | return -EBADMSG; |
1da177e4 | 2067 | } |
438d6c2c | 2068 | return 0; |
1da177e4 LT |
2069 | } |
2070 | ||
a1cdedac DB |
2071 | /** |
2072 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
2073 | * @client: Handle to slave device | |
2074 | * | |
2075 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
2076 | * else the byte received from the device. | |
2077 | */ | |
0cc43a18 | 2078 | s32 i2c_smbus_read_byte(const struct i2c_client *client) |
1da177e4 LT |
2079 | { |
2080 | union i2c_smbus_data data; | |
24a5bb7b DB |
2081 | int status; |
2082 | ||
2083 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2084 | I2C_SMBUS_READ, 0, | |
2085 | I2C_SMBUS_BYTE, &data); | |
2086 | return (status < 0) ? status : data.byte; | |
1da177e4 | 2087 | } |
c0564606 | 2088 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 2089 | |
a1cdedac DB |
2090 | /** |
2091 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
2092 | * @client: Handle to slave device | |
2093 | * @value: Byte to be sent | |
2094 | * | |
2095 | * This executes the SMBus "send byte" protocol, returning negative errno | |
2096 | * else zero on success. | |
2097 | */ | |
0cc43a18 | 2098 | s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value) |
1da177e4 | 2099 | { |
7225acf4 | 2100 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
421ef47b | 2101 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 2102 | } |
c0564606 | 2103 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 2104 | |
a1cdedac DB |
2105 | /** |
2106 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
2107 | * @client: Handle to slave device | |
2108 | * @command: Byte interpreted by slave | |
2109 | * | |
2110 | * This executes the SMBus "read byte" protocol, returning negative errno | |
2111 | * else a data byte received from the device. | |
2112 | */ | |
0cc43a18 | 2113 | s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command) |
1da177e4 LT |
2114 | { |
2115 | union i2c_smbus_data data; | |
24a5bb7b DB |
2116 | int status; |
2117 | ||
2118 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2119 | I2C_SMBUS_READ, command, | |
2120 | I2C_SMBUS_BYTE_DATA, &data); | |
2121 | return (status < 0) ? status : data.byte; | |
1da177e4 | 2122 | } |
c0564606 | 2123 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 2124 | |
a1cdedac DB |
2125 | /** |
2126 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
2127 | * @client: Handle to slave device | |
2128 | * @command: Byte interpreted by slave | |
2129 | * @value: Byte being written | |
2130 | * | |
2131 | * This executes the SMBus "write byte" protocol, returning negative errno | |
2132 | * else zero on success. | |
2133 | */ | |
0cc43a18 JD |
2134 | s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command, |
2135 | u8 value) | |
1da177e4 LT |
2136 | { |
2137 | union i2c_smbus_data data; | |
2138 | data.byte = value; | |
7225acf4 FH |
2139 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2140 | I2C_SMBUS_WRITE, command, | |
2141 | I2C_SMBUS_BYTE_DATA, &data); | |
1da177e4 | 2142 | } |
c0564606 | 2143 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 2144 | |
a1cdedac DB |
2145 | /** |
2146 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
2147 | * @client: Handle to slave device | |
2148 | * @command: Byte interpreted by slave | |
2149 | * | |
2150 | * This executes the SMBus "read word" protocol, returning negative errno | |
2151 | * else a 16-bit unsigned "word" received from the device. | |
2152 | */ | |
0cc43a18 | 2153 | s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command) |
1da177e4 LT |
2154 | { |
2155 | union i2c_smbus_data data; | |
24a5bb7b DB |
2156 | int status; |
2157 | ||
2158 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2159 | I2C_SMBUS_READ, command, | |
2160 | I2C_SMBUS_WORD_DATA, &data); | |
2161 | return (status < 0) ? status : data.word; | |
1da177e4 | 2162 | } |
c0564606 | 2163 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 2164 | |
a1cdedac DB |
2165 | /** |
2166 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
2167 | * @client: Handle to slave device | |
2168 | * @command: Byte interpreted by slave | |
2169 | * @value: 16-bit "word" being written | |
2170 | * | |
2171 | * This executes the SMBus "write word" protocol, returning negative errno | |
2172 | * else zero on success. | |
2173 | */ | |
0cc43a18 JD |
2174 | s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command, |
2175 | u16 value) | |
1da177e4 LT |
2176 | { |
2177 | union i2c_smbus_data data; | |
2178 | data.word = value; | |
7225acf4 FH |
2179 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2180 | I2C_SMBUS_WRITE, command, | |
2181 | I2C_SMBUS_WORD_DATA, &data); | |
1da177e4 | 2182 | } |
c0564606 | 2183 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 2184 | |
a64ec07d | 2185 | /** |
a1cdedac | 2186 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 2187 | * @client: Handle to slave device |
a1cdedac | 2188 | * @command: Byte interpreted by slave |
a64ec07d DB |
2189 | * @values: Byte array into which data will be read; big enough to hold |
2190 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
2191 | * | |
a1cdedac DB |
2192 | * This executes the SMBus "block read" protocol, returning negative errno |
2193 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
2194 | * |
2195 | * Note that using this function requires that the client's adapter support | |
2196 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
2197 | * support this; its emulation through I2C messaging relies on a specific | |
2198 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
2199 | */ | |
0cc43a18 | 2200 | s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command, |
b86a1bc8 JD |
2201 | u8 *values) |
2202 | { | |
2203 | union i2c_smbus_data data; | |
24a5bb7b | 2204 | int status; |
b86a1bc8 | 2205 | |
24a5bb7b DB |
2206 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2207 | I2C_SMBUS_READ, command, | |
2208 | I2C_SMBUS_BLOCK_DATA, &data); | |
2209 | if (status) | |
2210 | return status; | |
b86a1bc8 JD |
2211 | |
2212 | memcpy(values, &data.block[1], data.block[0]); | |
2213 | return data.block[0]; | |
2214 | } | |
2215 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
2216 | ||
a1cdedac DB |
2217 | /** |
2218 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
2219 | * @client: Handle to slave device | |
2220 | * @command: Byte interpreted by slave | |
2221 | * @length: Size of data block; SMBus allows at most 32 bytes | |
2222 | * @values: Byte array which will be written. | |
2223 | * | |
2224 | * This executes the SMBus "block write" protocol, returning negative errno | |
2225 | * else zero on success. | |
2226 | */ | |
0cc43a18 | 2227 | s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command, |
46f5ed75 | 2228 | u8 length, const u8 *values) |
1da177e4 LT |
2229 | { |
2230 | union i2c_smbus_data data; | |
7656032b | 2231 | |
1da177e4 LT |
2232 | if (length > I2C_SMBUS_BLOCK_MAX) |
2233 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 2234 | data.block[0] = length; |
7656032b | 2235 | memcpy(&data.block[1], values, length); |
7225acf4 FH |
2236 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2237 | I2C_SMBUS_WRITE, command, | |
2238 | I2C_SMBUS_BLOCK_DATA, &data); | |
1da177e4 | 2239 | } |
c0564606 | 2240 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
2241 | |
2242 | /* Returns the number of read bytes */ | |
0cc43a18 | 2243 | s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command, |
4b2643d7 | 2244 | u8 length, u8 *values) |
1da177e4 LT |
2245 | { |
2246 | union i2c_smbus_data data; | |
24a5bb7b | 2247 | int status; |
7656032b | 2248 | |
4b2643d7 JD |
2249 | if (length > I2C_SMBUS_BLOCK_MAX) |
2250 | length = I2C_SMBUS_BLOCK_MAX; | |
2251 | data.block[0] = length; | |
24a5bb7b DB |
2252 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2253 | I2C_SMBUS_READ, command, | |
2254 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
2255 | if (status < 0) | |
2256 | return status; | |
7656032b JD |
2257 | |
2258 | memcpy(values, &data.block[1], data.block[0]); | |
2259 | return data.block[0]; | |
1da177e4 | 2260 | } |
c0564606 | 2261 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 2262 | |
0cc43a18 | 2263 | s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command, |
46f5ed75 | 2264 | u8 length, const u8 *values) |
21bbd691 JD |
2265 | { |
2266 | union i2c_smbus_data data; | |
2267 | ||
2268 | if (length > I2C_SMBUS_BLOCK_MAX) | |
2269 | length = I2C_SMBUS_BLOCK_MAX; | |
2270 | data.block[0] = length; | |
2271 | memcpy(data.block + 1, values, length); | |
2272 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
2273 | I2C_SMBUS_WRITE, command, | |
2274 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
2275 | } | |
c0564606 | 2276 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 2277 | |
438d6c2c | 2278 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 2279 | No checking of parameters is done! */ |
7225acf4 FH |
2280 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, |
2281 | unsigned short flags, | |
2282 | char read_write, u8 command, int size, | |
2283 | union i2c_smbus_data *data) | |
1da177e4 LT |
2284 | { |
2285 | /* So we need to generate a series of msgs. In the case of writing, we | |
2286 | need to use only one message; when reading, we need two. We initialize | |
2287 | most things with sane defaults, to keep the code below somewhat | |
2288 | simpler. */ | |
5c50d188 HI |
2289 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
2290 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
7225acf4 | 2291 | int num = read_write == I2C_SMBUS_READ ? 2 : 1; |
1da177e4 | 2292 | int i; |
421ef47b | 2293 | u8 partial_pec = 0; |
24a5bb7b | 2294 | int status; |
230da094 S |
2295 | struct i2c_msg msg[2] = { |
2296 | { | |
2297 | .addr = addr, | |
2298 | .flags = flags, | |
2299 | .len = 1, | |
2300 | .buf = msgbuf0, | |
2301 | }, { | |
2302 | .addr = addr, | |
2303 | .flags = flags | I2C_M_RD, | |
2304 | .len = 0, | |
2305 | .buf = msgbuf1, | |
2306 | }, | |
2307 | }; | |
1da177e4 LT |
2308 | |
2309 | msgbuf0[0] = command; | |
7225acf4 | 2310 | switch (size) { |
1da177e4 LT |
2311 | case I2C_SMBUS_QUICK: |
2312 | msg[0].len = 0; | |
2313 | /* Special case: The read/write field is used as data */ | |
f29d2e02 RK |
2314 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
2315 | I2C_M_RD : 0); | |
1da177e4 LT |
2316 | num = 1; |
2317 | break; | |
2318 | case I2C_SMBUS_BYTE: | |
2319 | if (read_write == I2C_SMBUS_READ) { | |
2320 | /* Special case: only a read! */ | |
2321 | msg[0].flags = I2C_M_RD | flags; | |
2322 | num = 1; | |
2323 | } | |
2324 | break; | |
2325 | case I2C_SMBUS_BYTE_DATA: | |
2326 | if (read_write == I2C_SMBUS_READ) | |
2327 | msg[1].len = 1; | |
2328 | else { | |
2329 | msg[0].len = 2; | |
2330 | msgbuf0[1] = data->byte; | |
2331 | } | |
2332 | break; | |
2333 | case I2C_SMBUS_WORD_DATA: | |
2334 | if (read_write == I2C_SMBUS_READ) | |
2335 | msg[1].len = 2; | |
2336 | else { | |
7225acf4 | 2337 | msg[0].len = 3; |
1da177e4 | 2338 | msgbuf0[1] = data->word & 0xff; |
7eff82c8 | 2339 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
2340 | } |
2341 | break; | |
2342 | case I2C_SMBUS_PROC_CALL: | |
2343 | num = 2; /* Special case */ | |
2344 | read_write = I2C_SMBUS_READ; | |
2345 | msg[0].len = 3; | |
2346 | msg[1].len = 2; | |
2347 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 2348 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
2349 | break; |
2350 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 2351 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
2352 | msg[1].flags |= I2C_M_RECV_LEN; |
2353 | msg[1].len = 1; /* block length will be added by | |
2354 | the underlying bus driver */ | |
1da177e4 LT |
2355 | } else { |
2356 | msg[0].len = data->block[0] + 2; | |
2357 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
2358 | dev_err(&adapter->dev, |
2359 | "Invalid block write size %d\n", | |
2360 | data->block[0]); | |
2361 | return -EINVAL; | |
1da177e4 | 2362 | } |
5c50d188 | 2363 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
2364 | msgbuf0[i] = data->block[i-1]; |
2365 | } | |
2366 | break; | |
2367 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
2368 | num = 2; /* Another special case */ |
2369 | read_write = I2C_SMBUS_READ; | |
2370 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
2371 | dev_err(&adapter->dev, |
2372 | "Invalid block write size %d\n", | |
209d27c3 | 2373 | data->block[0]); |
24a5bb7b | 2374 | return -EINVAL; |
209d27c3 JD |
2375 | } |
2376 | msg[0].len = data->block[0] + 2; | |
2377 | for (i = 1; i < msg[0].len; i++) | |
2378 | msgbuf0[i] = data->block[i-1]; | |
2379 | msg[1].flags |= I2C_M_RECV_LEN; | |
2380 | msg[1].len = 1; /* block length will be added by | |
2381 | the underlying bus driver */ | |
2382 | break; | |
1da177e4 LT |
2383 | case I2C_SMBUS_I2C_BLOCK_DATA: |
2384 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 2385 | msg[1].len = data->block[0]; |
1da177e4 LT |
2386 | } else { |
2387 | msg[0].len = data->block[0] + 1; | |
30dac746 | 2388 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
2389 | dev_err(&adapter->dev, |
2390 | "Invalid block write size %d\n", | |
2391 | data->block[0]); | |
2392 | return -EINVAL; | |
1da177e4 LT |
2393 | } |
2394 | for (i = 1; i <= data->block[0]; i++) | |
2395 | msgbuf0[i] = data->block[i]; | |
2396 | } | |
2397 | break; | |
2398 | default: | |
24a5bb7b DB |
2399 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
2400 | return -EOPNOTSUPP; | |
1da177e4 LT |
2401 | } |
2402 | ||
421ef47b JD |
2403 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
2404 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
2405 | if (i) { | |
2406 | /* Compute PEC if first message is a write */ | |
2407 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 2408 | if (num == 1) /* Write only */ |
421ef47b JD |
2409 | i2c_smbus_add_pec(&msg[0]); |
2410 | else /* Write followed by read */ | |
2411 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
2412 | } | |
2413 | /* Ask for PEC if last message is a read */ | |
2414 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 2415 | msg[num-1].len++; |
421ef47b JD |
2416 | } |
2417 | ||
24a5bb7b DB |
2418 | status = i2c_transfer(adapter, msg, num); |
2419 | if (status < 0) | |
2420 | return status; | |
1da177e4 | 2421 | |
421ef47b JD |
2422 | /* Check PEC if last message is a read */ |
2423 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
2424 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
2425 | if (status < 0) | |
2426 | return status; | |
421ef47b JD |
2427 | } |
2428 | ||
1da177e4 | 2429 | if (read_write == I2C_SMBUS_READ) |
7225acf4 FH |
2430 | switch (size) { |
2431 | case I2C_SMBUS_BYTE: | |
2432 | data->byte = msgbuf0[0]; | |
2433 | break; | |
2434 | case I2C_SMBUS_BYTE_DATA: | |
2435 | data->byte = msgbuf1[0]; | |
2436 | break; | |
2437 | case I2C_SMBUS_WORD_DATA: | |
2438 | case I2C_SMBUS_PROC_CALL: | |
2439 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
2440 | break; | |
2441 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
2442 | for (i = 0; i < data->block[0]; i++) | |
2443 | data->block[i+1] = msgbuf1[i]; | |
2444 | break; | |
2445 | case I2C_SMBUS_BLOCK_DATA: | |
2446 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
2447 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
2448 | data->block[i] = msgbuf1[i]; | |
2449 | break; | |
1da177e4 LT |
2450 | } |
2451 | return 0; | |
2452 | } | |
2453 | ||
a1cdedac DB |
2454 | /** |
2455 | * i2c_smbus_xfer - execute SMBus protocol operations | |
2456 | * @adapter: Handle to I2C bus | |
2457 | * @addr: Address of SMBus slave on that bus | |
2458 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
2459 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
2460 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
2461 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
2462 | * @data: Data to be read or written | |
2463 | * | |
2464 | * This executes an SMBus protocol operation, and returns a negative | |
2465 | * errno code else zero on success. | |
2466 | */ | |
09b8ce0a | 2467 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
a1cdedac | 2468 | char read_write, u8 command, int protocol, |
09b8ce0a | 2469 | union i2c_smbus_data *data) |
1da177e4 | 2470 | { |
66b650f0 CW |
2471 | unsigned long orig_jiffies; |
2472 | int try; | |
1da177e4 | 2473 | s32 res; |
1da177e4 | 2474 | |
8a325997 DH |
2475 | /* If enabled, the following two tracepoints are conditional on |
2476 | * read_write and protocol. | |
2477 | */ | |
2478 | trace_smbus_write(adapter, addr, flags, read_write, | |
2479 | command, protocol, data); | |
2480 | trace_smbus_read(adapter, addr, flags, read_write, | |
2481 | command, protocol); | |
2482 | ||
d47726c5 | 2483 | flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB; |
1da177e4 LT |
2484 | |
2485 | if (adapter->algo->smbus_xfer) { | |
fe61e07e | 2486 | i2c_lock_adapter(adapter); |
66b650f0 CW |
2487 | |
2488 | /* Retry automatically on arbitration loss */ | |
2489 | orig_jiffies = jiffies; | |
2490 | for (res = 0, try = 0; try <= adapter->retries; try++) { | |
2491 | res = adapter->algo->smbus_xfer(adapter, addr, flags, | |
2492 | read_write, command, | |
2493 | protocol, data); | |
2494 | if (res != -EAGAIN) | |
2495 | break; | |
2496 | if (time_after(jiffies, | |
2497 | orig_jiffies + adapter->timeout)) | |
2498 | break; | |
2499 | } | |
fe61e07e | 2500 | i2c_unlock_adapter(adapter); |
1da177e4 | 2501 | |
72fc2c7f | 2502 | if (res != -EOPNOTSUPP || !adapter->algo->master_xfer) |
8a325997 | 2503 | goto trace; |
72fc2c7f LP |
2504 | /* |
2505 | * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't | |
2506 | * implement native support for the SMBus operation. | |
2507 | */ | |
2508 | } | |
2509 | ||
8a325997 DH |
2510 | res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, |
2511 | command, protocol, data); | |
2512 | ||
2513 | trace: | |
2514 | /* If enabled, the reply tracepoint is conditional on read_write. */ | |
2515 | trace_smbus_reply(adapter, addr, flags, read_write, | |
2516 | command, protocol, data); | |
2517 | trace_smbus_result(adapter, addr, flags, read_write, | |
2518 | command, protocol, res); | |
2519 | ||
2520 | return res; | |
1da177e4 | 2521 | } |
1da177e4 | 2522 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
2523 | |
2524 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
2525 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
2526 | MODULE_LICENSE("GPL"); |