]>
Commit | Line | Data |
---|---|---|
61e3d0f7 WS |
1 | /* |
2 | * Linux I2C core | |
3 | * | |
4 | * Copyright (C) 1995-99 Simon G. Vogl | |
5 | * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> | |
6 | * Mux support by Rodolfo Giometti <giometti@enneenne.com> and | |
7 | * Michael Lawnick <michael.lawnick.ext@nsn.com> | |
8 | * | |
9 | * Copyright (C) 2013-2017 Wolfram Sang <wsa@the-dreams.de> | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify it | |
12 | * under the terms of the GNU General Public License as published by the Free | |
13 | * Software Foundation; either version 2 of the License, or (at your option) | |
14 | * any later version. | |
15 | * | |
16 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
17 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | |
18 | * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. | |
687b81d0 | 19 | */ |
1da177e4 | 20 | |
44239a5a WS |
21 | #define pr_fmt(fmt) "i2c-core: " fmt |
22 | ||
b4e2f6ac | 23 | #include <dt-bindings/i2c/i2c.h> |
53feedf8 WS |
24 | #include <linux/acpi.h> |
25 | #include <linux/clk/clk-conf.h> | |
26 | #include <linux/completion.h> | |
5f9296ba | 27 | #include <linux/delay.h> |
53feedf8 | 28 | #include <linux/err.h> |
1da177e4 | 29 | #include <linux/errno.h> |
10c9ef04 | 30 | #include <linux/gpio/consumer.h> |
1da177e4 | 31 | #include <linux/i2c.h> |
f8756c67 | 32 | #include <linux/i2c-smbus.h> |
1da177e4 | 33 | #include <linux/idr.h> |
53feedf8 WS |
34 | #include <linux/init.h> |
35 | #include <linux/irqflags.h> | |
36 | #include <linux/jump_label.h> | |
37 | #include <linux/kernel.h> | |
38 | #include <linux/module.h> | |
b3585e4f | 39 | #include <linux/mutex.h> |
959e85f7 | 40 | #include <linux/of_device.h> |
53feedf8 | 41 | #include <linux/of.h> |
687b81d0 | 42 | #include <linux/of_irq.h> |
f48c767c | 43 | #include <linux/pm_domain.h> |
53feedf8 | 44 | #include <linux/pm_runtime.h> |
3fffd128 | 45 | #include <linux/pm_wakeirq.h> |
e1dba01c | 46 | #include <linux/property.h> |
53feedf8 WS |
47 | #include <linux/rwsem.h> |
48 | #include <linux/slab.h> | |
1da177e4 | 49 | |
9c1600ed DB |
50 | #include "i2c-core.h" |
51 | ||
d9a83d62 DH |
52 | #define CREATE_TRACE_POINTS |
53 | #include <trace/events/i2c.h> | |
1da177e4 | 54 | |
da899f55 WS |
55 | #define I2C_ADDR_OFFSET_TEN_BIT 0xa000 |
56 | #define I2C_ADDR_OFFSET_SLAVE 0x1000 | |
57 | ||
4d5538f5 BT |
58 | #define I2C_ADDR_7BITS_MAX 0x77 |
59 | #define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1) | |
60 | ||
dde67eb1 PR |
61 | #define I2C_ADDR_DEVICE_ID 0x7c |
62 | ||
61e3d0f7 WS |
63 | /* |
64 | * core_lock protects i2c_adapter_idr, and guarantees that device detection, | |
65 | * deletion of detected devices, and attach_adapter calls are serialized | |
66 | */ | |
caada32a | 67 | static DEFINE_MUTEX(core_lock); |
1da177e4 LT |
68 | static DEFINE_IDR(i2c_adapter_idr); |
69 | ||
4735c98f | 70 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
f37dd80a | 71 | |
50888b01 | 72 | static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key); |
95026658 | 73 | static bool is_registered; |
d9a83d62 | 74 | |
8cf868af | 75 | int i2c_transfer_trace_reg(void) |
d9a83d62 | 76 | { |
50888b01 | 77 | static_branch_inc(&i2c_trace_msg_key); |
8cf868af | 78 | return 0; |
d9a83d62 DH |
79 | } |
80 | ||
81 | void i2c_transfer_trace_unreg(void) | |
82 | { | |
50888b01 | 83 | static_branch_dec(&i2c_trace_msg_key); |
d9a83d62 DH |
84 | } |
85 | ||
5f441fca | 86 | const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
d2653e92 JD |
87 | const struct i2c_client *client) |
88 | { | |
811073b1 LJ |
89 | if (!(id && client)) |
90 | return NULL; | |
91 | ||
d2653e92 JD |
92 | while (id->name[0]) { |
93 | if (strcmp(client->name, id->name) == 0) | |
94 | return id; | |
95 | id++; | |
96 | } | |
97 | return NULL; | |
98 | } | |
5f441fca | 99 | EXPORT_SYMBOL_GPL(i2c_match_id); |
d2653e92 | 100 | |
1da177e4 LT |
101 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
102 | { | |
51298d12 JD |
103 | struct i2c_client *client = i2c_verify_client(dev); |
104 | struct i2c_driver *driver; | |
105 | ||
7b4fbc50 | 106 | |
959e85f7 | 107 | /* Attempt an OF style match */ |
da10c06a | 108 | if (i2c_of_match_device(drv->of_match_table, client)) |
959e85f7 GL |
109 | return 1; |
110 | ||
907ddf89 MW |
111 | /* Then ACPI style match */ |
112 | if (acpi_driver_match_device(dev, drv)) | |
113 | return 1; | |
114 | ||
51298d12 | 115 | driver = to_i2c_driver(drv); |
811073b1 LJ |
116 | |
117 | /* Finally an I2C match */ | |
118 | if (i2c_match_id(driver->id_table, client)) | |
119 | return 1; | |
d2653e92 | 120 | |
eb8a7908 | 121 | return 0; |
1da177e4 LT |
122 | } |
123 | ||
7eff2e7a | 124 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 | 125 | { |
8dcf3217 | 126 | struct i2c_client *client = to_i2c_client(dev); |
8c4ff6d0 ZR |
127 | int rc; |
128 | ||
af503716 JMC |
129 | rc = of_device_uevent_modalias(dev, env); |
130 | if (rc != -ENODEV) | |
131 | return rc; | |
132 | ||
8c4ff6d0 ZR |
133 | rc = acpi_device_uevent_modalias(dev, env); |
134 | if (rc != -ENODEV) | |
135 | return rc; | |
7b4fbc50 | 136 | |
8dcf3217 | 137 | return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
138 | } |
139 | ||
5f9296ba VK |
140 | /* i2c bus recovery routines */ |
141 | static int get_scl_gpio_value(struct i2c_adapter *adap) | |
142 | { | |
3991c5c8 | 143 | return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod); |
5f9296ba VK |
144 | } |
145 | ||
146 | static void set_scl_gpio_value(struct i2c_adapter *adap, int val) | |
147 | { | |
3991c5c8 | 148 | gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val); |
5f9296ba VK |
149 | } |
150 | ||
151 | static int get_sda_gpio_value(struct i2c_adapter *adap) | |
152 | { | |
3991c5c8 | 153 | return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod); |
5f9296ba VK |
154 | } |
155 | ||
8092178f | 156 | static void set_sda_gpio_value(struct i2c_adapter *adap, int val) |
5f9296ba | 157 | { |
8092178f | 158 | gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val); |
5f9296ba VK |
159 | } |
160 | ||
161 | /* | |
162 | * We are generating clock pulses. ndelay() determines durating of clk pulses. | |
163 | * We will generate clock with rate 100 KHz and so duration of both clock levels | |
164 | * is: delay in ns = (10^6 / 100) / 2 | |
165 | */ | |
166 | #define RECOVERY_NDELAY 5000 | |
167 | #define RECOVERY_CLK_CNT 9 | |
168 | ||
e1eb7d28 | 169 | int i2c_generic_scl_recovery(struct i2c_adapter *adap) |
5f9296ba VK |
170 | { |
171 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
172 | int i = 0, val = 1, ret = 0; | |
173 | ||
174 | if (bri->prepare_recovery) | |
2b2190a3 | 175 | bri->prepare_recovery(adap); |
5f9296ba | 176 | |
8b062608 | 177 | bri->set_scl(adap, val); |
72b08fcc WS |
178 | if (bri->set_sda) |
179 | bri->set_sda(adap, 1); | |
8b062608 JL |
180 | ndelay(RECOVERY_NDELAY); |
181 | ||
5f9296ba VK |
182 | /* |
183 | * By this time SCL is high, as we need to give 9 falling-rising edges | |
184 | */ | |
185 | while (i++ < RECOVERY_CLK_CNT * 2) { | |
186 | if (val) { | |
5f9296ba VK |
187 | /* SCL shouldn't be low here */ |
188 | if (!bri->get_scl(adap)) { | |
189 | dev_err(&adap->dev, | |
190 | "SCL is stuck low, exit recovery\n"); | |
191 | ret = -EBUSY; | |
192 | break; | |
193 | } | |
1f35b865 CF |
194 | /* Break if SDA is high */ |
195 | if (bri->get_sda && bri->get_sda(adap)) | |
196 | break; | |
5f9296ba VK |
197 | } |
198 | ||
199 | val = !val; | |
200 | bri->set_scl(adap, val); | |
abe41184 WS |
201 | |
202 | /* | |
203 | * If we can set SDA, we will always create STOP here to ensure | |
204 | * the additional pulses will do no harm. This is achieved by | |
205 | * letting SDA follow SCL half a cycle later. | |
206 | */ | |
207 | ndelay(RECOVERY_NDELAY / 2); | |
208 | if (bri->set_sda) | |
209 | bri->set_sda(adap, val); | |
210 | ndelay(RECOVERY_NDELAY / 2); | |
5f9296ba VK |
211 | } |
212 | ||
1f35b865 CF |
213 | /* check if recovery actually succeeded */ |
214 | if (bri->get_sda && !bri->get_sda(adap)) | |
215 | ret = -EBUSY; | |
216 | ||
2806e6ad WS |
217 | /* If all went well, send STOP for a sane bus state. */ |
218 | if (ret == 0 && bri->set_sda) { | |
219 | bri->set_scl(adap, 0); | |
220 | ndelay(RECOVERY_NDELAY / 2); | |
221 | bri->set_sda(adap, 0); | |
222 | ndelay(RECOVERY_NDELAY / 2); | |
223 | bri->set_scl(adap, 1); | |
224 | ndelay(RECOVERY_NDELAY / 2); | |
225 | bri->set_sda(adap, 1); | |
226 | ndelay(RECOVERY_NDELAY / 2); | |
227 | } | |
228 | ||
5f9296ba | 229 | if (bri->unprepare_recovery) |
2b2190a3 | 230 | bri->unprepare_recovery(adap); |
5f9296ba VK |
231 | |
232 | return ret; | |
233 | } | |
c1c21f4e | 234 | EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery); |
5f9296ba | 235 | |
5f9296ba VK |
236 | int i2c_recover_bus(struct i2c_adapter *adap) |
237 | { | |
238 | if (!adap->bus_recovery_info) | |
239 | return -EOPNOTSUPP; | |
240 | ||
241 | dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); | |
242 | return adap->bus_recovery_info->recover_bus(adap); | |
243 | } | |
c1c21f4e | 244 | EXPORT_SYMBOL_GPL(i2c_recover_bus); |
5f9296ba | 245 | |
d3b11d83 WS |
246 | static void i2c_init_recovery(struct i2c_adapter *adap) |
247 | { | |
248 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
249 | char *err_str; | |
250 | ||
251 | if (!bri) | |
252 | return; | |
253 | ||
254 | if (!bri->recover_bus) { | |
255 | err_str = "no recover_bus() found"; | |
256 | goto err; | |
257 | } | |
258 | ||
3991c5c8 | 259 | if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) { |
d3b11d83 WS |
260 | bri->get_scl = get_scl_gpio_value; |
261 | bri->set_scl = set_scl_gpio_value; | |
8092178f | 262 | if (bri->sda_gpiod) { |
3991c5c8 | 263 | bri->get_sda = get_sda_gpio_value; |
8092178f WS |
264 | /* FIXME: add proper flag instead of '0' once available */ |
265 | if (gpiod_get_direction(bri->sda_gpiod) == 0) | |
266 | bri->set_sda = set_sda_gpio_value; | |
267 | } | |
3991c5c8 PR |
268 | return; |
269 | } | |
270 | ||
e1eb7d28 | 271 | if (bri->recover_bus == i2c_generic_scl_recovery) { |
d3b11d83 WS |
272 | /* Generic SCL recovery */ |
273 | if (!bri->set_scl || !bri->get_scl) { | |
274 | err_str = "no {get|set}_scl() found"; | |
275 | goto err; | |
276 | } | |
277 | } | |
278 | ||
279 | return; | |
280 | err: | |
281 | dev_err(&adap->dev, "Not using recovery: %s\n", err_str); | |
282 | adap->bus_recovery_info = NULL; | |
283 | } | |
284 | ||
4d5538f5 BT |
285 | static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client) |
286 | { | |
287 | struct i2c_adapter *adap = client->adapter; | |
288 | unsigned int irq; | |
289 | ||
290 | if (!adap->host_notify_domain) | |
291 | return -ENXIO; | |
292 | ||
293 | if (client->flags & I2C_CLIENT_TEN) | |
294 | return -EINVAL; | |
295 | ||
296 | irq = irq_find_mapping(adap->host_notify_domain, client->addr); | |
297 | if (!irq) | |
298 | irq = irq_create_mapping(adap->host_notify_domain, | |
299 | client->addr); | |
300 | ||
301 | return irq > 0 ? irq : -ENXIO; | |
302 | } | |
303 | ||
f37dd80a | 304 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 305 | { |
51298d12 JD |
306 | struct i2c_client *client = i2c_verify_client(dev); |
307 | struct i2c_driver *driver; | |
50c3304a | 308 | int status; |
7b4fbc50 | 309 | |
51298d12 JD |
310 | if (!client) |
311 | return 0; | |
312 | ||
d1d84bb9 HG |
313 | driver = to_i2c_driver(dev->driver); |
314 | ||
315 | if (!client->irq && !driver->disable_i2c_core_irq_mapping) { | |
845c8770 MW |
316 | int irq = -ENOENT; |
317 | ||
331c3425 DT |
318 | if (client->flags & I2C_CLIENT_HOST_NOTIFY) { |
319 | dev_dbg(dev, "Using Host Notify IRQ\n"); | |
320 | irq = i2c_smbus_host_notify_to_irq(client); | |
321 | } else if (dev->of_node) { | |
3fffd128 DT |
322 | irq = of_irq_get_byname(dev->of_node, "irq"); |
323 | if (irq == -EINVAL || irq == -ENODATA) | |
324 | irq = of_irq_get(dev->of_node, 0); | |
325 | } else if (ACPI_COMPANION(dev)) { | |
845c8770 | 326 | irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0); |
3fffd128 | 327 | } |
6f34be74 | 328 | if (irq == -EPROBE_DEFER) |
2fd36c55 | 329 | return irq; |
331c3425 | 330 | |
6f34be74 GU |
331 | if (irq < 0) |
332 | irq = 0; | |
2fd36c55 LP |
333 | |
334 | client->irq = irq; | |
335 | } | |
336 | ||
da10c06a | 337 | /* |
f4b17a14 JMC |
338 | * An I2C ID table is not mandatory, if and only if, a suitable OF |
339 | * or ACPI ID table is supplied for the probing device. | |
da10c06a LJ |
340 | */ |
341 | if (!driver->id_table && | |
c64ffff7 | 342 | !i2c_acpi_match_device(dev->driver->acpi_match_table, client) && |
da10c06a | 343 | !i2c_of_match_device(dev->driver->of_match_table, client)) |
7b4fbc50 | 344 | return -ENODEV; |
0acc2b32 | 345 | |
3fffd128 DT |
346 | if (client->flags & I2C_CLIENT_WAKE) { |
347 | int wakeirq = -ENOENT; | |
348 | ||
349 | if (dev->of_node) { | |
350 | wakeirq = of_irq_get_byname(dev->of_node, "wakeup"); | |
351 | if (wakeirq == -EPROBE_DEFER) | |
352 | return wakeirq; | |
353 | } | |
354 | ||
355 | device_init_wakeup(&client->dev, true); | |
356 | ||
357 | if (wakeirq > 0 && wakeirq != client->irq) | |
358 | status = dev_pm_set_dedicated_wake_irq(dev, wakeirq); | |
359 | else if (client->irq > 0) | |
c18fba23 | 360 | status = dev_pm_set_wake_irq(dev, client->irq); |
3fffd128 DT |
361 | else |
362 | status = 0; | |
363 | ||
364 | if (status) | |
b93d3d37 | 365 | dev_warn(&client->dev, "failed to set up wakeup irq\n"); |
3fffd128 DT |
366 | } |
367 | ||
7b4fbc50 | 368 | dev_dbg(dev, "probe\n"); |
d2653e92 | 369 | |
86be408b SN |
370 | status = of_clk_set_defaults(dev->of_node, false); |
371 | if (status < 0) | |
3fffd128 | 372 | goto err_clear_wakeup_irq; |
86be408b | 373 | |
e09b0d4e | 374 | status = dev_pm_domain_attach(&client->dev, true); |
e6a20b6c | 375 | if (status) |
74cedd30 KB |
376 | goto err_clear_wakeup_irq; |
377 | ||
b8a1a4cd LJ |
378 | /* |
379 | * When there are no more users of probe(), | |
380 | * rename probe_new to probe. | |
381 | */ | |
382 | if (driver->probe_new) | |
383 | status = driver->probe_new(client); | |
384 | else if (driver->probe) | |
385 | status = driver->probe(client, | |
386 | i2c_match_id(driver->id_table, client)); | |
387 | else | |
388 | status = -EINVAL; | |
389 | ||
74cedd30 KB |
390 | if (status) |
391 | goto err_detach_pm_domain; | |
72fa818e | 392 | |
3fffd128 DT |
393 | return 0; |
394 | ||
395 | err_detach_pm_domain: | |
396 | dev_pm_domain_detach(&client->dev, true); | |
397 | err_clear_wakeup_irq: | |
398 | dev_pm_clear_wake_irq(&client->dev); | |
399 | device_init_wakeup(&client->dev, false); | |
50c3304a | 400 | return status; |
f37dd80a | 401 | } |
1da177e4 | 402 | |
f37dd80a DB |
403 | static int i2c_device_remove(struct device *dev) |
404 | { | |
51298d12 | 405 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 | 406 | struct i2c_driver *driver; |
72fa818e | 407 | int status = 0; |
a1d9e6e4 | 408 | |
51298d12 | 409 | if (!client || !dev->driver) |
a1d9e6e4 DB |
410 | return 0; |
411 | ||
412 | driver = to_i2c_driver(dev->driver); | |
413 | if (driver->remove) { | |
414 | dev_dbg(dev, "remove\n"); | |
415 | status = driver->remove(client); | |
a1d9e6e4 | 416 | } |
72fa818e | 417 | |
e09b0d4e | 418 | dev_pm_domain_detach(&client->dev, true); |
3fffd128 DT |
419 | |
420 | dev_pm_clear_wake_irq(&client->dev); | |
421 | device_init_wakeup(&client->dev, false); | |
422 | ||
a1d9e6e4 | 423 | return status; |
1da177e4 LT |
424 | } |
425 | ||
f37dd80a | 426 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 427 | { |
51298d12 | 428 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
429 | struct i2c_driver *driver; |
430 | ||
51298d12 | 431 | if (!client || !dev->driver) |
f37dd80a DB |
432 | return; |
433 | driver = to_i2c_driver(dev->driver); | |
434 | if (driver->shutdown) | |
51298d12 | 435 | driver->shutdown(client); |
1da177e4 LT |
436 | } |
437 | ||
9c1600ed DB |
438 | static void i2c_client_dev_release(struct device *dev) |
439 | { | |
440 | kfree(to_i2c_client(dev)); | |
441 | } | |
442 | ||
09b8ce0a | 443 | static ssize_t |
4f8cf824 | 444 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 445 | { |
4f8cf824 JD |
446 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
447 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 | 448 | } |
a5eb71b2 | 449 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
7b4fbc50 | 450 | |
09b8ce0a ZX |
451 | static ssize_t |
452 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
453 | { |
454 | struct i2c_client *client = to_i2c_client(dev); | |
8c4ff6d0 ZR |
455 | int len; |
456 | ||
af503716 JMC |
457 | len = of_device_modalias(dev, buf, PAGE_SIZE); |
458 | if (len != -ENODEV) | |
459 | return len; | |
460 | ||
8c4ff6d0 ZR |
461 | len = acpi_device_modalias(dev, buf, PAGE_SIZE -1); |
462 | if (len != -ENODEV) | |
463 | return len; | |
464 | ||
eb8a7908 | 465 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 | 466 | } |
51298d12 JD |
467 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
468 | ||
469 | static struct attribute *i2c_dev_attrs[] = { | |
470 | &dev_attr_name.attr, | |
7b4fbc50 | 471 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
472 | &dev_attr_modalias.attr, |
473 | NULL | |
474 | }; | |
a5eb71b2 | 475 | ATTRIBUTE_GROUPS(i2c_dev); |
54067ee2 | 476 | |
e9ca9eb9 | 477 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
478 | .name = "i2c", |
479 | .match = i2c_device_match, | |
480 | .probe = i2c_device_probe, | |
481 | .remove = i2c_device_remove, | |
482 | .shutdown = i2c_device_shutdown, | |
b864c7d5 | 483 | }; |
e9ca9eb9 | 484 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 485 | |
00a06c22 | 486 | struct device_type i2c_client_type = { |
a5eb71b2 | 487 | .groups = i2c_dev_groups, |
51298d12 JD |
488 | .uevent = i2c_device_uevent, |
489 | .release = i2c_client_dev_release, | |
490 | }; | |
00a06c22 | 491 | EXPORT_SYMBOL_GPL(i2c_client_type); |
51298d12 | 492 | |
9b766b81 DB |
493 | |
494 | /** | |
495 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
496 | * @dev: device, probably from some driver model iterator | |
497 | * | |
498 | * When traversing the driver model tree, perhaps using driver model | |
499 | * iterators like @device_for_each_child(), you can't assume very much | |
500 | * about the nodes you find. Use this function to avoid oopses caused | |
501 | * by wrongly treating some non-I2C device as an i2c_client. | |
502 | */ | |
503 | struct i2c_client *i2c_verify_client(struct device *dev) | |
504 | { | |
51298d12 | 505 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
506 | ? to_i2c_client(dev) |
507 | : NULL; | |
508 | } | |
509 | EXPORT_SYMBOL(i2c_verify_client); | |
510 | ||
511 | ||
da899f55 WS |
512 | /* Return a unique address which takes the flags of the client into account */ |
513 | static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client) | |
514 | { | |
515 | unsigned short addr = client->addr; | |
516 | ||
517 | /* For some client flags, add an arbitrary offset to avoid collisions */ | |
518 | if (client->flags & I2C_CLIENT_TEN) | |
519 | addr |= I2C_ADDR_OFFSET_TEN_BIT; | |
520 | ||
521 | if (client->flags & I2C_CLIENT_SLAVE) | |
522 | addr |= I2C_ADDR_OFFSET_SLAVE; | |
523 | ||
524 | return addr; | |
525 | } | |
526 | ||
3a89db5f | 527 | /* This is a permissive address validity check, I2C address map constraints |
25985edc | 528 | * are purposely not enforced, except for the general call address. */ |
398432ed | 529 | static int i2c_check_addr_validity(unsigned int addr, unsigned short flags) |
3a89db5f | 530 | { |
c4019b70 | 531 | if (flags & I2C_CLIENT_TEN) { |
3a89db5f | 532 | /* 10-bit address, all values are valid */ |
c4019b70 | 533 | if (addr > 0x3ff) |
3a89db5f JD |
534 | return -EINVAL; |
535 | } else { | |
536 | /* 7-bit address, reject the general call address */ | |
c4019b70 | 537 | if (addr == 0x00 || addr > 0x7f) |
3a89db5f JD |
538 | return -EINVAL; |
539 | } | |
540 | return 0; | |
541 | } | |
542 | ||
656b8761 JD |
543 | /* And this is a strict address validity check, used when probing. If a |
544 | * device uses a reserved address, then it shouldn't be probed. 7-bit | |
545 | * addressing is assumed, 10-bit address devices are rare and should be | |
546 | * explicitly enumerated. */ | |
e4991ecd | 547 | int i2c_check_7bit_addr_validity_strict(unsigned short addr) |
656b8761 JD |
548 | { |
549 | /* | |
550 | * Reserved addresses per I2C specification: | |
551 | * 0x00 General call address / START byte | |
552 | * 0x01 CBUS address | |
553 | * 0x02 Reserved for different bus format | |
554 | * 0x03 Reserved for future purposes | |
555 | * 0x04-0x07 Hs-mode master code | |
556 | * 0x78-0x7b 10-bit slave addressing | |
557 | * 0x7c-0x7f Reserved for future purposes | |
558 | */ | |
559 | if (addr < 0x08 || addr > 0x77) | |
560 | return -EINVAL; | |
561 | return 0; | |
562 | } | |
563 | ||
3b5f794b JD |
564 | static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
565 | { | |
566 | struct i2c_client *client = i2c_verify_client(dev); | |
567 | int addr = *(int *)addrp; | |
568 | ||
9bccc70a | 569 | if (client && i2c_encode_flags_to_addr(client) == addr) |
3b5f794b JD |
570 | return -EBUSY; |
571 | return 0; | |
572 | } | |
573 | ||
0826374b ML |
574 | /* walk up mux tree */ |
575 | static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
576 | { | |
97cc4d49 | 577 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
578 | int result; |
579 | ||
580 | result = device_for_each_child(&adapter->dev, &addr, | |
581 | __i2c_check_addr_busy); | |
582 | ||
97cc4d49 JD |
583 | if (!result && parent) |
584 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
585 | |
586 | return result; | |
587 | } | |
588 | ||
589 | /* recurse down mux tree */ | |
590 | static int i2c_check_mux_children(struct device *dev, void *addrp) | |
591 | { | |
592 | int result; | |
593 | ||
594 | if (dev->type == &i2c_adapter_type) | |
595 | result = device_for_each_child(dev, addrp, | |
596 | i2c_check_mux_children); | |
597 | else | |
598 | result = __i2c_check_addr_busy(dev, addrp); | |
599 | ||
600 | return result; | |
601 | } | |
602 | ||
3b5f794b JD |
603 | static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) |
604 | { | |
97cc4d49 | 605 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
606 | int result = 0; |
607 | ||
97cc4d49 JD |
608 | if (parent) |
609 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
610 | |
611 | if (!result) | |
612 | result = device_for_each_child(&adapter->dev, &addr, | |
613 | i2c_check_mux_children); | |
614 | ||
615 | return result; | |
3b5f794b JD |
616 | } |
617 | ||
fe61e07e | 618 | /** |
8320f495 | 619 | * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment |
fe61e07e | 620 | * @adapter: Target I2C bus segment |
8320f495 PR |
621 | * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT |
622 | * locks only this branch in the adapter tree | |
fe61e07e | 623 | */ |
8320f495 PR |
624 | static void i2c_adapter_lock_bus(struct i2c_adapter *adapter, |
625 | unsigned int flags) | |
fe61e07e | 626 | { |
fa96f0cb | 627 | rt_mutex_lock(&adapter->bus_lock); |
fe61e07e | 628 | } |
fe61e07e JD |
629 | |
630 | /** | |
8320f495 | 631 | * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment |
fe61e07e | 632 | * @adapter: Target I2C bus segment |
8320f495 PR |
633 | * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT |
634 | * trylocks only this branch in the adapter tree | |
fe61e07e | 635 | */ |
8320f495 PR |
636 | static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter, |
637 | unsigned int flags) | |
fe61e07e | 638 | { |
fa96f0cb | 639 | return rt_mutex_trylock(&adapter->bus_lock); |
fe61e07e JD |
640 | } |
641 | ||
642 | /** | |
8320f495 | 643 | * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment |
fe61e07e | 644 | * @adapter: Target I2C bus segment |
8320f495 PR |
645 | * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT |
646 | * unlocks only this branch in the adapter tree | |
fe61e07e | 647 | */ |
8320f495 PR |
648 | static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter, |
649 | unsigned int flags) | |
fe61e07e | 650 | { |
fa96f0cb | 651 | rt_mutex_unlock(&adapter->bus_lock); |
fe61e07e | 652 | } |
fe61e07e | 653 | |
70762abb | 654 | static void i2c_dev_set_name(struct i2c_adapter *adap, |
728fe6ce HG |
655 | struct i2c_client *client, |
656 | struct i2c_board_info const *info) | |
70762abb JN |
657 | { |
658 | struct acpi_device *adev = ACPI_COMPANION(&client->dev); | |
659 | ||
728fe6ce HG |
660 | if (info && info->dev_name) { |
661 | dev_set_name(&client->dev, "i2c-%s", info->dev_name); | |
662 | return; | |
663 | } | |
664 | ||
70762abb JN |
665 | if (adev) { |
666 | dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); | |
667 | return; | |
668 | } | |
669 | ||
70762abb | 670 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), |
da899f55 | 671 | i2c_encode_flags_to_addr(client)); |
70762abb JN |
672 | } |
673 | ||
4124c4eb DT |
674 | static int i2c_dev_irq_from_resources(const struct resource *resources, |
675 | unsigned int num_resources) | |
676 | { | |
677 | struct irq_data *irqd; | |
678 | int i; | |
679 | ||
680 | for (i = 0; i < num_resources; i++) { | |
681 | const struct resource *r = &resources[i]; | |
682 | ||
683 | if (resource_type(r) != IORESOURCE_IRQ) | |
684 | continue; | |
685 | ||
686 | if (r->flags & IORESOURCE_BITS) { | |
687 | irqd = irq_get_irq_data(r->start); | |
688 | if (!irqd) | |
689 | break; | |
690 | ||
691 | irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); | |
692 | } | |
693 | ||
694 | return r->start; | |
695 | } | |
696 | ||
697 | return 0; | |
698 | } | |
699 | ||
9c1600ed | 700 | /** |
f8a227e8 | 701 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
702 | * @adap: the adapter managing the device |
703 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 704 | * Context: can sleep |
9c1600ed | 705 | * |
f8a227e8 JD |
706 | * Create an i2c device. Binding is handled through driver model |
707 | * probe()/remove() methods. A driver may be bound to this device when we | |
708 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
709 | * load the driver module). This call is not appropriate for use by mainboard | |
710 | * initialization logic, which usually runs during an arch_initcall() long | |
711 | * before any i2c_adapter could exist. | |
9c1600ed DB |
712 | * |
713 | * This returns the new i2c client, which may be saved for later use with | |
714 | * i2c_unregister_device(); or NULL to indicate an error. | |
715 | */ | |
716 | struct i2c_client * | |
717 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
718 | { | |
719 | struct i2c_client *client; | |
720 | int status; | |
721 | ||
722 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
723 | if (!client) | |
724 | return NULL; | |
725 | ||
726 | client->adapter = adap; | |
727 | ||
728 | client->dev.platform_data = info->platform_data; | |
ee35425c | 729 | client->flags = info->flags; |
9c1600ed | 730 | client->addr = info->addr; |
4124c4eb | 731 | |
9c1600ed | 732 | client->irq = info->irq; |
4124c4eb DT |
733 | if (!client->irq) |
734 | client->irq = i2c_dev_irq_from_resources(info->resources, | |
735 | info->num_resources); | |
9c1600ed | 736 | |
9c1600ed DB |
737 | strlcpy(client->name, info->type, sizeof(client->name)); |
738 | ||
c4019b70 | 739 | status = i2c_check_addr_validity(client->addr, client->flags); |
3a89db5f JD |
740 | if (status) { |
741 | dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", | |
742 | client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); | |
743 | goto out_err_silent; | |
744 | } | |
745 | ||
f8a227e8 | 746 | /* Check for address business */ |
9bccc70a | 747 | status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client)); |
f8a227e8 JD |
748 | if (status) |
749 | goto out_err; | |
750 | ||
751 | client->dev.parent = &client->adapter->dev; | |
752 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 753 | client->dev.type = &i2c_client_type; |
04782265 | 754 | client->dev.of_node = of_node_get(info->of_node); |
ce793486 | 755 | client->dev.fwnode = info->fwnode; |
f8a227e8 | 756 | |
728fe6ce | 757 | i2c_dev_set_name(adap, client, info); |
d3e1b617 DT |
758 | |
759 | if (info->properties) { | |
760 | status = device_add_properties(&client->dev, info->properties); | |
761 | if (status) { | |
762 | dev_err(&adap->dev, | |
763 | "Failed to add properties to client %s: %d\n", | |
764 | client->name, status); | |
04782265 | 765 | goto out_err_put_of_node; |
d3e1b617 DT |
766 | } |
767 | } | |
768 | ||
f8a227e8 JD |
769 | status = device_register(&client->dev); |
770 | if (status) | |
d3e1b617 | 771 | goto out_free_props; |
f8a227e8 | 772 | |
f8a227e8 JD |
773 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
774 | client->name, dev_name(&client->dev)); | |
775 | ||
9c1600ed | 776 | return client; |
f8a227e8 | 777 | |
d3e1b617 DT |
778 | out_free_props: |
779 | if (info->properties) | |
780 | device_remove_properties(&client->dev); | |
04782265 BB |
781 | out_err_put_of_node: |
782 | of_node_put(info->of_node); | |
f8a227e8 | 783 | out_err: |
b93d3d37 AS |
784 | dev_err(&adap->dev, |
785 | "Failed to register i2c client %s at 0x%02x (%d)\n", | |
786 | client->name, client->addr, status); | |
3a89db5f | 787 | out_err_silent: |
f8a227e8 JD |
788 | kfree(client); |
789 | return NULL; | |
9c1600ed DB |
790 | } |
791 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
792 | ||
793 | ||
794 | /** | |
795 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
796 | * @client: value returned from i2c_new_device() | |
d64f73be | 797 | * Context: can sleep |
9c1600ed DB |
798 | */ |
799 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 800 | { |
7b43dd19 AS |
801 | if (!client) |
802 | return; | |
e0638fa4 LW |
803 | |
804 | if (client->dev.of_node) { | |
4f001fd3 | 805 | of_node_clear_flag(client->dev.of_node, OF_POPULATED); |
e0638fa4 LW |
806 | of_node_put(client->dev.of_node); |
807 | } | |
808 | ||
525e6fab OP |
809 | if (ACPI_COMPANION(&client->dev)) |
810 | acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev)); | |
a1d9e6e4 DB |
811 | device_unregister(&client->dev); |
812 | } | |
9c1600ed | 813 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
814 | |
815 | ||
60b129d7 JD |
816 | static const struct i2c_device_id dummy_id[] = { |
817 | { "dummy", 0 }, | |
818 | { }, | |
819 | }; | |
820 | ||
d2653e92 JD |
821 | static int dummy_probe(struct i2c_client *client, |
822 | const struct i2c_device_id *id) | |
823 | { | |
824 | return 0; | |
825 | } | |
826 | ||
827 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
828 | { |
829 | return 0; | |
830 | } | |
831 | ||
832 | static struct i2c_driver dummy_driver = { | |
833 | .driver.name = "dummy", | |
d2653e92 JD |
834 | .probe = dummy_probe, |
835 | .remove = dummy_remove, | |
60b129d7 | 836 | .id_table = dummy_id, |
e9f1373b DB |
837 | }; |
838 | ||
839 | /** | |
840 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
841 | * @adapter: the adapter managing the device | |
842 | * @address: seven bit address to be used | |
e9f1373b DB |
843 | * Context: can sleep |
844 | * | |
845 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
846 | * with devices that consume multiple addresses. Examples of such chips | |
847 | * include various EEPROMS (like 24c04 and 24c08 models). | |
848 | * | |
849 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
850 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
851 | * And second, this prevents the specified address from being bound to a | |
852 | * different driver. | |
853 | * | |
854 | * This returns the new i2c client, which should be saved for later use with | |
855 | * i2c_unregister_device(); or NULL to indicate an error. | |
856 | */ | |
09b8ce0a | 857 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
858 | { |
859 | struct i2c_board_info info = { | |
60b129d7 | 860 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
861 | }; |
862 | ||
e9f1373b DB |
863 | return i2c_new_device(adapter, &info); |
864 | } | |
865 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
866 | ||
0f614d83 JMH |
867 | /** |
868 | * i2c_new_secondary_device - Helper to get the instantiated secondary address | |
869 | * and create the associated device | |
870 | * @client: Handle to the primary client | |
871 | * @name: Handle to specify which secondary address to get | |
872 | * @default_addr: Used as a fallback if no secondary address was specified | |
873 | * Context: can sleep | |
874 | * | |
875 | * I2C clients can be composed of multiple I2C slaves bound together in a single | |
876 | * component. The I2C client driver then binds to the master I2C slave and needs | |
877 | * to create I2C dummy clients to communicate with all the other slaves. | |
878 | * | |
879 | * This function creates and returns an I2C dummy client whose I2C address is | |
880 | * retrieved from the platform firmware based on the given slave name. If no | |
881 | * address is specified by the firmware default_addr is used. | |
882 | * | |
883 | * On DT-based platforms the address is retrieved from the "reg" property entry | |
884 | * cell whose "reg-names" value matches the slave name. | |
885 | * | |
886 | * This returns the new i2c client, which should be saved for later use with | |
887 | * i2c_unregister_device(); or NULL to indicate an error. | |
888 | */ | |
889 | struct i2c_client *i2c_new_secondary_device(struct i2c_client *client, | |
890 | const char *name, | |
891 | u16 default_addr) | |
892 | { | |
893 | struct device_node *np = client->dev.of_node; | |
894 | u32 addr = default_addr; | |
895 | int i; | |
896 | ||
897 | if (np) { | |
898 | i = of_property_match_string(np, "reg-names", name); | |
899 | if (i >= 0) | |
900 | of_property_read_u32_index(np, "reg", i, &addr); | |
901 | } | |
902 | ||
903 | dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr); | |
904 | return i2c_new_dummy(client->adapter, addr); | |
905 | } | |
906 | EXPORT_SYMBOL_GPL(i2c_new_secondary_device); | |
907 | ||
f37dd80a DB |
908 | /* ------------------------------------------------------------------------- */ |
909 | ||
16ffadfc DB |
910 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
911 | ||
83eaaed0 | 912 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 913 | { |
ef2c8321 | 914 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
915 | complete(&adap->dev_released); |
916 | } | |
917 | ||
8dd1fe15 | 918 | unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) |
390946b1 JD |
919 | { |
920 | unsigned int depth = 0; | |
921 | ||
922 | while ((adapter = i2c_parent_is_i2c_adapter(adapter))) | |
923 | depth++; | |
924 | ||
2771dc34 BG |
925 | WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES, |
926 | "adapter depth exceeds lockdep subclass limit\n"); | |
927 | ||
390946b1 JD |
928 | return depth; |
929 | } | |
8dd1fe15 | 930 | EXPORT_SYMBOL_GPL(i2c_adapter_depth); |
390946b1 | 931 | |
99cd8e25 JD |
932 | /* |
933 | * Let users instantiate I2C devices through sysfs. This can be used when | |
934 | * platform initialization code doesn't contain the proper data for | |
935 | * whatever reason. Also useful for drivers that do device detection and | |
936 | * detection fails, either because the device uses an unexpected address, | |
937 | * or this is a compatible device with different ID register values. | |
938 | * | |
939 | * Parameter checking may look overzealous, but we really don't want | |
940 | * the user to provide incorrect parameters. | |
941 | */ | |
942 | static ssize_t | |
943 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
944 | const char *buf, size_t count) | |
945 | { | |
946 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
947 | struct i2c_board_info info; | |
948 | struct i2c_client *client; | |
949 | char *blank, end; | |
950 | int res; | |
951 | ||
99cd8e25 JD |
952 | memset(&info, 0, sizeof(struct i2c_board_info)); |
953 | ||
954 | blank = strchr(buf, ' '); | |
955 | if (!blank) { | |
956 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
957 | return -EINVAL; | |
958 | } | |
959 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
960 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
961 | return -EINVAL; | |
962 | } | |
963 | memcpy(info.type, buf, blank - buf); | |
964 | ||
965 | /* Parse remaining parameters, reject extra parameters */ | |
966 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
967 | if (res < 1) { | |
968 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
969 | return -EINVAL; | |
970 | } | |
971 | if (res > 1 && end != '\n') { | |
972 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
973 | return -EINVAL; | |
974 | } | |
975 | ||
cfa0327b WS |
976 | if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) { |
977 | info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT; | |
978 | info.flags |= I2C_CLIENT_TEN; | |
979 | } | |
980 | ||
981 | if (info.addr & I2C_ADDR_OFFSET_SLAVE) { | |
982 | info.addr &= ~I2C_ADDR_OFFSET_SLAVE; | |
983 | info.flags |= I2C_CLIENT_SLAVE; | |
984 | } | |
985 | ||
99cd8e25 JD |
986 | client = i2c_new_device(adap, &info); |
987 | if (!client) | |
3a89db5f | 988 | return -EINVAL; |
99cd8e25 JD |
989 | |
990 | /* Keep track of the added device */ | |
dafc50d1 | 991 | mutex_lock(&adap->userspace_clients_lock); |
6629dcff | 992 | list_add_tail(&client->detected, &adap->userspace_clients); |
dafc50d1 | 993 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
994 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
995 | info.type, info.addr); | |
996 | ||
997 | return count; | |
998 | } | |
a5eb71b2 | 999 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
99cd8e25 JD |
1000 | |
1001 | /* | |
1002 | * And of course let the users delete the devices they instantiated, if | |
1003 | * they got it wrong. This interface can only be used to delete devices | |
1004 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
1005 | * don't delete devices to which some kernel code still has references. | |
1006 | * | |
1007 | * Parameter checking may look overzealous, but we really don't want | |
1008 | * the user to delete the wrong device. | |
1009 | */ | |
1010 | static ssize_t | |
1011 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
1012 | const char *buf, size_t count) | |
1013 | { | |
1014 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
1015 | struct i2c_client *client, *next; | |
1016 | unsigned short addr; | |
1017 | char end; | |
1018 | int res; | |
1019 | ||
1020 | /* Parse parameters, reject extra parameters */ | |
1021 | res = sscanf(buf, "%hi%c", &addr, &end); | |
1022 | if (res < 1) { | |
1023 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
1024 | return -EINVAL; | |
1025 | } | |
1026 | if (res > 1 && end != '\n') { | |
1027 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
1028 | return -EINVAL; | |
1029 | } | |
1030 | ||
1031 | /* Make sure the device was added through sysfs */ | |
1032 | res = -ENOENT; | |
390946b1 JD |
1033 | mutex_lock_nested(&adap->userspace_clients_lock, |
1034 | i2c_adapter_depth(adap)); | |
6629dcff JD |
1035 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1036 | detected) { | |
cfa0327b | 1037 | if (i2c_encode_flags_to_addr(client) == addr) { |
99cd8e25 JD |
1038 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
1039 | "delete_device", client->name, client->addr); | |
1040 | ||
1041 | list_del(&client->detected); | |
1042 | i2c_unregister_device(client); | |
1043 | res = count; | |
1044 | break; | |
1045 | } | |
1046 | } | |
dafc50d1 | 1047 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
1048 | |
1049 | if (res < 0) | |
1050 | dev_err(dev, "%s: Can't find device in list\n", | |
1051 | "delete_device"); | |
1052 | return res; | |
1053 | } | |
e9b526fe AS |
1054 | static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, |
1055 | i2c_sysfs_delete_device); | |
4f8cf824 JD |
1056 | |
1057 | static struct attribute *i2c_adapter_attrs[] = { | |
1058 | &dev_attr_name.attr, | |
1059 | &dev_attr_new_device.attr, | |
1060 | &dev_attr_delete_device.attr, | |
1061 | NULL | |
1062 | }; | |
a5eb71b2 | 1063 | ATTRIBUTE_GROUPS(i2c_adapter); |
b119dc3f | 1064 | |
0826374b | 1065 | struct device_type i2c_adapter_type = { |
a5eb71b2 | 1066 | .groups = i2c_adapter_groups, |
4f8cf824 | 1067 | .release = i2c_adapter_dev_release, |
1da177e4 | 1068 | }; |
0826374b | 1069 | EXPORT_SYMBOL_GPL(i2c_adapter_type); |
1da177e4 | 1070 | |
643dd09e SW |
1071 | /** |
1072 | * i2c_verify_adapter - return parameter as i2c_adapter or NULL | |
1073 | * @dev: device, probably from some driver model iterator | |
1074 | * | |
1075 | * When traversing the driver model tree, perhaps using driver model | |
1076 | * iterators like @device_for_each_child(), you can't assume very much | |
1077 | * about the nodes you find. Use this function to avoid oopses caused | |
1078 | * by wrongly treating some non-I2C device as an i2c_adapter. | |
1079 | */ | |
1080 | struct i2c_adapter *i2c_verify_adapter(struct device *dev) | |
1081 | { | |
1082 | return (dev->type == &i2c_adapter_type) | |
1083 | ? to_i2c_adapter(dev) | |
1084 | : NULL; | |
1085 | } | |
1086 | EXPORT_SYMBOL(i2c_verify_adapter); | |
1087 | ||
2bb5095a JD |
1088 | #ifdef CONFIG_I2C_COMPAT |
1089 | static struct class_compat *i2c_adapter_compat_class; | |
1090 | #endif | |
1091 | ||
9c1600ed DB |
1092 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
1093 | { | |
1094 | struct i2c_devinfo *devinfo; | |
1095 | ||
f18c41da | 1096 | down_read(&__i2c_board_lock); |
9c1600ed DB |
1097 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
1098 | if (devinfo->busnum == adapter->nr | |
1099 | && !i2c_new_device(adapter, | |
1100 | &devinfo->board_info)) | |
09b8ce0a ZX |
1101 | dev_err(&adapter->dev, |
1102 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
1103 | devinfo->board_info.addr); |
1104 | } | |
f18c41da | 1105 | up_read(&__i2c_board_lock); |
9c1600ed DB |
1106 | } |
1107 | ||
69b0089a JD |
1108 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
1109 | struct i2c_adapter *adap) | |
026526f5 | 1110 | { |
4735c98f JD |
1111 | /* Detect supported devices on that bus, and instantiate them */ |
1112 | i2c_detect(adap, driver); | |
1113 | ||
1114 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 | 1115 | if (driver->attach_adapter) { |
a920ff41 JD |
1116 | dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n", |
1117 | driver->driver.name); | |
b93d3d37 AS |
1118 | dev_warn(&adap->dev, |
1119 | "Please use another way to instantiate your i2c_client\n"); | |
026526f5 JD |
1120 | /* We ignore the return code; if it fails, too bad */ |
1121 | driver->attach_adapter(adap); | |
1122 | } | |
1123 | return 0; | |
1124 | } | |
1125 | ||
69b0089a JD |
1126 | static int __process_new_adapter(struct device_driver *d, void *data) |
1127 | { | |
1128 | return i2c_do_add_adapter(to_i2c_driver(d), data); | |
1129 | } | |
1130 | ||
d1ed7985 PR |
1131 | static const struct i2c_lock_operations i2c_adapter_lock_ops = { |
1132 | .lock_bus = i2c_adapter_lock_bus, | |
1133 | .trylock_bus = i2c_adapter_trylock_bus, | |
1134 | .unlock_bus = i2c_adapter_unlock_bus, | |
1135 | }; | |
1136 | ||
4d5538f5 BT |
1137 | static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap) |
1138 | { | |
1139 | struct irq_domain *domain = adap->host_notify_domain; | |
1140 | irq_hw_number_t hwirq; | |
1141 | ||
1142 | if (!domain) | |
1143 | return; | |
1144 | ||
1145 | for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++) | |
1146 | irq_dispose_mapping(irq_find_mapping(domain, hwirq)); | |
1147 | ||
1148 | irq_domain_remove(domain); | |
1149 | adap->host_notify_domain = NULL; | |
1150 | } | |
1151 | ||
1152 | static int i2c_host_notify_irq_map(struct irq_domain *h, | |
1153 | unsigned int virq, | |
1154 | irq_hw_number_t hw_irq_num) | |
1155 | { | |
1156 | irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); | |
1157 | ||
1158 | return 0; | |
1159 | } | |
1160 | ||
1161 | static const struct irq_domain_ops i2c_host_notify_irq_ops = { | |
1162 | .map = i2c_host_notify_irq_map, | |
1163 | }; | |
1164 | ||
1165 | static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap) | |
1166 | { | |
1167 | struct irq_domain *domain; | |
1168 | ||
1169 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY)) | |
1170 | return 0; | |
1171 | ||
1172 | domain = irq_domain_create_linear(adap->dev.fwnode, | |
1173 | I2C_ADDR_7BITS_COUNT, | |
1174 | &i2c_host_notify_irq_ops, adap); | |
1175 | if (!domain) | |
1176 | return -ENOMEM; | |
1177 | ||
1178 | adap->host_notify_domain = domain; | |
1179 | ||
1180 | return 0; | |
1181 | } | |
1182 | ||
1183 | /** | |
1184 | * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct | |
1185 | * I2C client. | |
1186 | * @adap: the adapter | |
1187 | * @addr: the I2C address of the notifying device | |
1188 | * Context: can't sleep | |
1189 | * | |
1190 | * Helper function to be called from an I2C bus driver's interrupt | |
1191 | * handler. It will schedule the Host Notify IRQ. | |
1192 | */ | |
1193 | int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr) | |
1194 | { | |
1195 | int irq; | |
1196 | ||
1197 | if (!adap) | |
1198 | return -EINVAL; | |
1199 | ||
1200 | irq = irq_find_mapping(adap->host_notify_domain, addr); | |
1201 | if (irq <= 0) | |
1202 | return -ENXIO; | |
1203 | ||
1204 | generic_handle_irq(irq); | |
1205 | ||
1206 | return 0; | |
1207 | } | |
1208 | EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify); | |
1209 | ||
6e13e641 | 1210 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 1211 | { |
ce0dffaf | 1212 | int res = -EINVAL; |
1da177e4 | 1213 | |
1d0b19c9 | 1214 | /* Can't register until after driver model init */ |
95026658 | 1215 | if (WARN_ON(!is_registered)) { |
35fc37f8 JD |
1216 | res = -EAGAIN; |
1217 | goto out_list; | |
1218 | } | |
1d0b19c9 | 1219 | |
2236baa7 | 1220 | /* Sanity checks */ |
8ddfe410 | 1221 | if (WARN(!adap->name[0], "i2c adapter has no name")) |
ce0dffaf | 1222 | goto out_list; |
8ddfe410 WS |
1223 | |
1224 | if (!adap->algo) { | |
44239a5a | 1225 | pr_err("adapter '%s': no algo supplied!\n", adap->name); |
ce0dffaf | 1226 | goto out_list; |
2236baa7 JD |
1227 | } |
1228 | ||
d1ed7985 PR |
1229 | if (!adap->lock_ops) |
1230 | adap->lock_ops = &i2c_adapter_lock_ops; | |
8320f495 | 1231 | |
194684e5 | 1232 | rt_mutex_init(&adap->bus_lock); |
6ef91fcc | 1233 | rt_mutex_init(&adap->mux_lock); |
dafc50d1 | 1234 | mutex_init(&adap->userspace_clients_lock); |
6629dcff | 1235 | INIT_LIST_HEAD(&adap->userspace_clients); |
1da177e4 | 1236 | |
8fcfef6e JD |
1237 | /* Set default timeout to 1 second if not already set */ |
1238 | if (adap->timeout == 0) | |
1239 | adap->timeout = HZ; | |
1240 | ||
4d5538f5 BT |
1241 | /* register soft irqs for Host Notify */ |
1242 | res = i2c_setup_host_notify_irq_domain(adap); | |
1243 | if (res) { | |
1244 | pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n", | |
1245 | adap->name, res); | |
1246 | goto out_list; | |
1247 | } | |
1248 | ||
27d9c183 | 1249 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
1250 | adap->dev.bus = &i2c_bus_type; |
1251 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 | 1252 | res = device_register(&adap->dev); |
8ddfe410 | 1253 | if (res) { |
44239a5a | 1254 | pr_err("adapter '%s': can't register device (%d)\n", adap->name, res); |
b119c6c9 | 1255 | goto out_list; |
8ddfe410 | 1256 | } |
1da177e4 | 1257 | |
f8756c67 PR |
1258 | res = of_i2c_setup_smbus_alert(adap); |
1259 | if (res) | |
1260 | goto out_reg; | |
1261 | ||
b6d7b3d1 JD |
1262 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
1263 | ||
6ada5c1e | 1264 | pm_runtime_no_callbacks(&adap->dev); |
04f59143 | 1265 | pm_suspend_ignore_children(&adap->dev, true); |
9f924169 | 1266 | pm_runtime_enable(&adap->dev); |
6ada5c1e | 1267 | |
2bb5095a JD |
1268 | #ifdef CONFIG_I2C_COMPAT |
1269 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
1270 | adap->dev.parent); | |
1271 | if (res) | |
1272 | dev_warn(&adap->dev, | |
1273 | "Failed to create compatibility class link\n"); | |
1274 | #endif | |
1275 | ||
d3b11d83 | 1276 | i2c_init_recovery(adap); |
5f9296ba | 1277 | |
729d6dd5 | 1278 | /* create pre-declared device nodes */ |
687b81d0 | 1279 | of_i2c_register_devices(adap); |
aec809fc JN |
1280 | i2c_acpi_register_devices(adap); |
1281 | i2c_acpi_install_space_handler(adap); | |
687b81d0 | 1282 | |
6e13e641 DB |
1283 | if (adap->nr < __i2c_first_dynamic_bus_num) |
1284 | i2c_scan_static_board_info(adap); | |
1285 | ||
4735c98f | 1286 | /* Notify drivers */ |
35fc37f8 | 1287 | mutex_lock(&core_lock); |
d6703281 | 1288 | bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); |
caada32a | 1289 | mutex_unlock(&core_lock); |
35fc37f8 JD |
1290 | |
1291 | return 0; | |
b119c6c9 | 1292 | |
f8756c67 PR |
1293 | out_reg: |
1294 | init_completion(&adap->dev_released); | |
1295 | device_unregister(&adap->dev); | |
1296 | wait_for_completion(&adap->dev_released); | |
b119c6c9 | 1297 | out_list: |
35fc37f8 | 1298 | mutex_lock(&core_lock); |
b119c6c9 | 1299 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
1300 | mutex_unlock(&core_lock); |
1301 | return res; | |
1da177e4 LT |
1302 | } |
1303 | ||
ee5c2744 DA |
1304 | /** |
1305 | * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 | |
1306 | * @adap: the adapter to register (with adap->nr initialized) | |
1307 | * Context: can sleep | |
1308 | * | |
1309 | * See i2c_add_numbered_adapter() for details. | |
1310 | */ | |
1311 | static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1312 | { | |
84d0b617 | 1313 | int id; |
ee5c2744 DA |
1314 | |
1315 | mutex_lock(&core_lock); | |
84d0b617 | 1316 | id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL); |
ee5c2744 | 1317 | mutex_unlock(&core_lock); |
84d0b617 | 1318 | if (WARN(id < 0, "couldn't get idr")) |
ee5c2744 DA |
1319 | return id == -ENOSPC ? -EBUSY : id; |
1320 | ||
1321 | return i2c_register_adapter(adap); | |
1322 | } | |
1323 | ||
6e13e641 DB |
1324 | /** |
1325 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
1326 | * @adapter: the adapter to add | |
d64f73be | 1327 | * Context: can sleep |
6e13e641 DB |
1328 | * |
1329 | * This routine is used to declare an I2C adapter when its bus number | |
ee5c2744 DA |
1330 | * doesn't matter or when its bus number is specified by an dt alias. |
1331 | * Examples of bases when the bus number doesn't matter: I2C adapters | |
1332 | * dynamically added by USB links or PCI plugin cards. | |
6e13e641 DB |
1333 | * |
1334 | * When this returns zero, a new bus number was allocated and stored | |
1335 | * in adap->nr, and the specified adapter became available for clients. | |
1336 | * Otherwise, a negative errno value is returned. | |
1337 | */ | |
1338 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
1339 | { | |
ee5c2744 | 1340 | struct device *dev = &adapter->dev; |
4ae42b0f | 1341 | int id; |
6e13e641 | 1342 | |
ee5c2744 DA |
1343 | if (dev->of_node) { |
1344 | id = of_alias_get_id(dev->of_node, "i2c"); | |
1345 | if (id >= 0) { | |
1346 | adapter->nr = id; | |
1347 | return __i2c_add_numbered_adapter(adapter); | |
1348 | } | |
1349 | } | |
1350 | ||
caada32a | 1351 | mutex_lock(&core_lock); |
4ae42b0f TH |
1352 | id = idr_alloc(&i2c_adapter_idr, adapter, |
1353 | __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); | |
caada32a | 1354 | mutex_unlock(&core_lock); |
84d0b617 | 1355 | if (WARN(id < 0, "couldn't get idr")) |
4ae42b0f | 1356 | return id; |
6e13e641 DB |
1357 | |
1358 | adapter->nr = id; | |
4ae42b0f | 1359 | |
6e13e641 DB |
1360 | return i2c_register_adapter(adapter); |
1361 | } | |
1362 | EXPORT_SYMBOL(i2c_add_adapter); | |
1363 | ||
1364 | /** | |
1365 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
1366 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 1367 | * Context: can sleep |
6e13e641 DB |
1368 | * |
1369 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
1370 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
1371 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
1372 | * is used to properly configure I2C devices. |
1373 | * | |
488bf314 GL |
1374 | * If the requested bus number is set to -1, then this function will behave |
1375 | * identically to i2c_add_adapter, and will dynamically assign a bus number. | |
1376 | * | |
6e13e641 DB |
1377 | * If no devices have pre-been declared for this bus, then be sure to |
1378 | * register the adapter before any dynamically allocated ones. Otherwise | |
1379 | * the required bus ID may not be available. | |
1380 | * | |
1381 | * When this returns zero, the specified adapter became available for | |
1382 | * clients using the bus number provided in adap->nr. Also, the table | |
1383 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
1384 | * and the appropriate driver model device nodes are created. Otherwise, a | |
1385 | * negative errno value is returned. | |
1386 | */ | |
1387 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1388 | { | |
488bf314 GL |
1389 | if (adap->nr == -1) /* -1 means dynamically assign bus id */ |
1390 | return i2c_add_adapter(adap); | |
6e13e641 | 1391 | |
ee5c2744 | 1392 | return __i2c_add_numbered_adapter(adap); |
6e13e641 DB |
1393 | } |
1394 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
1395 | ||
19baba4c | 1396 | static void i2c_do_del_adapter(struct i2c_driver *driver, |
69b0089a | 1397 | struct i2c_adapter *adapter) |
026526f5 | 1398 | { |
4735c98f | 1399 | struct i2c_client *client, *_n; |
026526f5 | 1400 | |
acec211c JD |
1401 | /* Remove the devices we created ourselves as the result of hardware |
1402 | * probing (using a driver's detect method) */ | |
4735c98f JD |
1403 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
1404 | if (client->adapter == adapter) { | |
1405 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
1406 | client->name, client->addr); | |
1407 | list_del(&client->detected); | |
1408 | i2c_unregister_device(client); | |
1409 | } | |
1410 | } | |
026526f5 JD |
1411 | } |
1412 | ||
e549c2b5 | 1413 | static int __unregister_client(struct device *dev, void *dummy) |
5219bf88 JD |
1414 | { |
1415 | struct i2c_client *client = i2c_verify_client(dev); | |
1416 | if (client && strcmp(client->name, "dummy")) | |
1417 | i2c_unregister_device(client); | |
1418 | return 0; | |
1419 | } | |
1420 | ||
1421 | static int __unregister_dummy(struct device *dev, void *dummy) | |
e549c2b5 JD |
1422 | { |
1423 | struct i2c_client *client = i2c_verify_client(dev); | |
7b43dd19 | 1424 | i2c_unregister_device(client); |
e549c2b5 JD |
1425 | return 0; |
1426 | } | |
1427 | ||
69b0089a JD |
1428 | static int __process_removed_adapter(struct device_driver *d, void *data) |
1429 | { | |
19baba4c LPC |
1430 | i2c_do_del_adapter(to_i2c_driver(d), data); |
1431 | return 0; | |
69b0089a JD |
1432 | } |
1433 | ||
d64f73be DB |
1434 | /** |
1435 | * i2c_del_adapter - unregister I2C adapter | |
1436 | * @adap: the adapter being unregistered | |
1437 | * Context: can sleep | |
1438 | * | |
1439 | * This unregisters an I2C adapter which was previously registered | |
1440 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
1441 | */ | |
71546300 | 1442 | void i2c_del_adapter(struct i2c_adapter *adap) |
1da177e4 | 1443 | { |
35fc37f8 | 1444 | struct i2c_adapter *found; |
bbd2d9c9 | 1445 | struct i2c_client *client, *next; |
1da177e4 LT |
1446 | |
1447 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
1448 | mutex_lock(&core_lock); |
1449 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
1450 | mutex_unlock(&core_lock); | |
1451 | if (found != adap) { | |
44239a5a | 1452 | pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name); |
71546300 | 1453 | return; |
1da177e4 LT |
1454 | } |
1455 | ||
aec809fc | 1456 | i2c_acpi_remove_space_handler(adap); |
026526f5 | 1457 | /* Tell drivers about this removal */ |
35fc37f8 | 1458 | mutex_lock(&core_lock); |
19baba4c | 1459 | bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 1460 | __process_removed_adapter); |
35fc37f8 | 1461 | mutex_unlock(&core_lock); |
1da177e4 | 1462 | |
bbd2d9c9 | 1463 | /* Remove devices instantiated from sysfs */ |
390946b1 JD |
1464 | mutex_lock_nested(&adap->userspace_clients_lock, |
1465 | i2c_adapter_depth(adap)); | |
6629dcff JD |
1466 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1467 | detected) { | |
1468 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, | |
1469 | client->addr); | |
1470 | list_del(&client->detected); | |
1471 | i2c_unregister_device(client); | |
bbd2d9c9 | 1472 | } |
dafc50d1 | 1473 | mutex_unlock(&adap->userspace_clients_lock); |
bbd2d9c9 | 1474 | |
e549c2b5 | 1475 | /* Detach any active clients. This can't fail, thus we do not |
5219bf88 JD |
1476 | * check the returned value. This is a two-pass process, because |
1477 | * we can't remove the dummy devices during the first pass: they | |
1478 | * could have been instantiated by real devices wishing to clean | |
1479 | * them up properly, so we give them a chance to do that first. */ | |
19baba4c LPC |
1480 | device_for_each_child(&adap->dev, NULL, __unregister_client); |
1481 | device_for_each_child(&adap->dev, NULL, __unregister_dummy); | |
1da177e4 | 1482 | |
2bb5095a JD |
1483 | #ifdef CONFIG_I2C_COMPAT |
1484 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
1485 | adap->dev.parent); | |
1486 | #endif | |
1487 | ||
c5567521 TLSC |
1488 | /* device name is gone after device_unregister */ |
1489 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); | |
1490 | ||
9f924169 WS |
1491 | pm_runtime_disable(&adap->dev); |
1492 | ||
4d5538f5 BT |
1493 | i2c_host_notify_irq_teardown(adap); |
1494 | ||
26680ee2 WS |
1495 | /* wait until all references to the device are gone |
1496 | * | |
1497 | * FIXME: This is old code and should ideally be replaced by an | |
1498 | * alternative which results in decoupling the lifetime of the struct | |
1499 | * device from the i2c_adapter, like spi or netdev do. Any solution | |
95cc1e3d | 1500 | * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled! |
26680ee2 | 1501 | */ |
1da177e4 | 1502 | init_completion(&adap->dev_released); |
1da177e4 | 1503 | device_unregister(&adap->dev); |
1da177e4 | 1504 | wait_for_completion(&adap->dev_released); |
1da177e4 | 1505 | |
6e13e641 | 1506 | /* free bus id */ |
35fc37f8 | 1507 | mutex_lock(&core_lock); |
1da177e4 | 1508 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 1509 | mutex_unlock(&core_lock); |
1da177e4 | 1510 | |
bd4bc3db JD |
1511 | /* Clear the device structure in case this adapter is ever going to be |
1512 | added again */ | |
1513 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
1da177e4 | 1514 | } |
c0564606 | 1515 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 | 1516 | |
54177ccf WS |
1517 | /** |
1518 | * i2c_parse_fw_timings - get I2C related timing parameters from firmware | |
1519 | * @dev: The device to scan for I2C timing properties | |
1520 | * @t: the i2c_timings struct to be filled with values | |
1521 | * @use_defaults: bool to use sane defaults derived from the I2C specification | |
1522 | * when properties are not found, otherwise use 0 | |
1523 | * | |
1524 | * Scan the device for the generic I2C properties describing timing parameters | |
1525 | * for the signal and fill the given struct with the results. If a property was | |
1526 | * not found and use_defaults was true, then maximum timings are assumed which | |
1527 | * are derived from the I2C specification. If use_defaults is not used, the | |
1528 | * results will be 0, so drivers can apply their own defaults later. The latter | |
1529 | * is mainly intended for avoiding regressions of existing drivers which want | |
1530 | * to switch to this function. New drivers almost always should use the defaults. | |
1531 | */ | |
1532 | ||
1533 | void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults) | |
1534 | { | |
1535 | int ret; | |
1536 | ||
1537 | memset(t, 0, sizeof(*t)); | |
1538 | ||
1539 | ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz); | |
1540 | if (ret && use_defaults) | |
1541 | t->bus_freq_hz = 100000; | |
1542 | ||
1543 | ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns); | |
1544 | if (ret && use_defaults) { | |
1545 | if (t->bus_freq_hz <= 100000) | |
1546 | t->scl_rise_ns = 1000; | |
1547 | else if (t->bus_freq_hz <= 400000) | |
1548 | t->scl_rise_ns = 300; | |
1549 | else | |
1550 | t->scl_rise_ns = 120; | |
1551 | } | |
1552 | ||
1553 | ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns); | |
1554 | if (ret && use_defaults) { | |
1555 | if (t->bus_freq_hz <= 400000) | |
1556 | t->scl_fall_ns = 300; | |
1557 | else | |
1558 | t->scl_fall_ns = 120; | |
1559 | } | |
1560 | ||
1561 | device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns); | |
1562 | ||
1563 | ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns); | |
1564 | if (ret && use_defaults) | |
1565 | t->sda_fall_ns = t->scl_fall_ns; | |
1566 | } | |
1567 | EXPORT_SYMBOL_GPL(i2c_parse_fw_timings); | |
1568 | ||
7b4fbc50 DB |
1569 | /* ------------------------------------------------------------------------- */ |
1570 | ||
7ae31482 JD |
1571 | int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) |
1572 | { | |
1573 | int res; | |
1574 | ||
1575 | mutex_lock(&core_lock); | |
1576 | res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); | |
1577 | mutex_unlock(&core_lock); | |
1578 | ||
1579 | return res; | |
1580 | } | |
1581 | EXPORT_SYMBOL_GPL(i2c_for_each_dev); | |
1582 | ||
69b0089a | 1583 | static int __process_new_driver(struct device *dev, void *data) |
7f101a97 | 1584 | { |
4f8cf824 JD |
1585 | if (dev->type != &i2c_adapter_type) |
1586 | return 0; | |
69b0089a | 1587 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
7f101a97 DY |
1588 | } |
1589 | ||
7b4fbc50 DB |
1590 | /* |
1591 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 1592 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
1593 | */ |
1594 | ||
de59cf9e | 1595 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 1596 | { |
7eebcb7c | 1597 | int res; |
1da177e4 | 1598 | |
1d0b19c9 | 1599 | /* Can't register until after driver model init */ |
95026658 | 1600 | if (WARN_ON(!is_registered)) |
1d0b19c9 DB |
1601 | return -EAGAIN; |
1602 | ||
1da177e4 | 1603 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 1604 | driver->driver.owner = owner; |
1da177e4 | 1605 | driver->driver.bus = &i2c_bus_type; |
147b36d5 | 1606 | INIT_LIST_HEAD(&driver->clients); |
1da177e4 | 1607 | |
729d6dd5 | 1608 | /* When registration returns, the driver core |
6e13e641 DB |
1609 | * will have called probe() for all matching-but-unbound devices. |
1610 | */ | |
1da177e4 LT |
1611 | res = driver_register(&driver->driver); |
1612 | if (res) | |
7eebcb7c | 1613 | return res; |
438d6c2c | 1614 | |
44239a5a | 1615 | pr_debug("driver [%s] registered\n", driver->driver.name); |
1da177e4 | 1616 | |
4735c98f | 1617 | /* Walk the adapters that are already present */ |
7ae31482 | 1618 | i2c_for_each_dev(driver, __process_new_driver); |
35fc37f8 | 1619 | |
7f101a97 DY |
1620 | return 0; |
1621 | } | |
1622 | EXPORT_SYMBOL(i2c_register_driver); | |
1623 | ||
69b0089a | 1624 | static int __process_removed_driver(struct device *dev, void *data) |
7f101a97 | 1625 | { |
19baba4c LPC |
1626 | if (dev->type == &i2c_adapter_type) |
1627 | i2c_do_del_adapter(data, to_i2c_adapter(dev)); | |
1628 | return 0; | |
1da177e4 LT |
1629 | } |
1630 | ||
a1d9e6e4 DB |
1631 | /** |
1632 | * i2c_del_driver - unregister I2C driver | |
1633 | * @driver: the driver being unregistered | |
d64f73be | 1634 | * Context: can sleep |
a1d9e6e4 | 1635 | */ |
b3e82096 | 1636 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 1637 | { |
7ae31482 | 1638 | i2c_for_each_dev(driver, __process_removed_driver); |
1da177e4 LT |
1639 | |
1640 | driver_unregister(&driver->driver); | |
44239a5a | 1641 | pr_debug("driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 1642 | } |
c0564606 | 1643 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 1644 | |
7b4fbc50 DB |
1645 | /* ------------------------------------------------------------------------- */ |
1646 | ||
e48d3319 JD |
1647 | /** |
1648 | * i2c_use_client - increments the reference count of the i2c client structure | |
1649 | * @client: the client being referenced | |
1650 | * | |
1651 | * Each live reference to a client should be refcounted. The driver model does | |
1652 | * that automatically as part of driver binding, so that most drivers don't | |
1653 | * need to do this explicitly: they hold a reference until they're unbound | |
1654 | * from the device. | |
1655 | * | |
1656 | * A pointer to the client with the incremented reference counter is returned. | |
1657 | */ | |
1658 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 1659 | { |
6ea438ec DB |
1660 | if (client && get_device(&client->dev)) |
1661 | return client; | |
1662 | return NULL; | |
1da177e4 | 1663 | } |
c0564606 | 1664 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 1665 | |
e48d3319 JD |
1666 | /** |
1667 | * i2c_release_client - release a use of the i2c client structure | |
1668 | * @client: the client being no longer referenced | |
1669 | * | |
1670 | * Must be called when a user of a client is finished with it. | |
1671 | */ | |
1672 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 1673 | { |
6ea438ec DB |
1674 | if (client) |
1675 | put_device(&client->dev); | |
1da177e4 | 1676 | } |
c0564606 | 1677 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 1678 | |
9b766b81 DB |
1679 | struct i2c_cmd_arg { |
1680 | unsigned cmd; | |
1681 | void *arg; | |
1682 | }; | |
1683 | ||
1684 | static int i2c_cmd(struct device *dev, void *_arg) | |
1685 | { | |
1686 | struct i2c_client *client = i2c_verify_client(dev); | |
1687 | struct i2c_cmd_arg *arg = _arg; | |
0acc2b32 LPC |
1688 | struct i2c_driver *driver; |
1689 | ||
1690 | if (!client || !client->dev.driver) | |
1691 | return 0; | |
9b766b81 | 1692 | |
0acc2b32 LPC |
1693 | driver = to_i2c_driver(client->dev.driver); |
1694 | if (driver->command) | |
1695 | driver->command(client, arg->cmd, arg->arg); | |
9b766b81 DB |
1696 | return 0; |
1697 | } | |
1698 | ||
1da177e4 LT |
1699 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
1700 | { | |
9b766b81 | 1701 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 1702 | |
9b766b81 DB |
1703 | cmd_arg.cmd = cmd; |
1704 | cmd_arg.arg = arg; | |
1705 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 1706 | } |
c0564606 | 1707 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
1708 | |
1709 | static int __init i2c_init(void) | |
1710 | { | |
1711 | int retval; | |
1712 | ||
03bde7c3 WS |
1713 | retval = of_alias_get_highest_id("i2c"); |
1714 | ||
1715 | down_write(&__i2c_board_lock); | |
1716 | if (retval >= __i2c_first_dynamic_bus_num) | |
1717 | __i2c_first_dynamic_bus_num = retval + 1; | |
1718 | up_write(&__i2c_board_lock); | |
1719 | ||
1da177e4 | 1720 | retval = bus_register(&i2c_bus_type); |
1da177e4 LT |
1721 | if (retval) |
1722 | return retval; | |
b980a26d WS |
1723 | |
1724 | is_registered = true; | |
1725 | ||
2bb5095a JD |
1726 | #ifdef CONFIG_I2C_COMPAT |
1727 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
1728 | if (!i2c_adapter_compat_class) { | |
1729 | retval = -ENOMEM; | |
1730 | goto bus_err; | |
1731 | } | |
1732 | #endif | |
e9f1373b DB |
1733 | retval = i2c_add_driver(&dummy_driver); |
1734 | if (retval) | |
2bb5095a | 1735 | goto class_err; |
ea7513bb PA |
1736 | |
1737 | if (IS_ENABLED(CONFIG_OF_DYNAMIC)) | |
1738 | WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)); | |
525e6fab OP |
1739 | if (IS_ENABLED(CONFIG_ACPI)) |
1740 | WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier)); | |
ea7513bb | 1741 | |
e9f1373b DB |
1742 | return 0; |
1743 | ||
2bb5095a JD |
1744 | class_err: |
1745 | #ifdef CONFIG_I2C_COMPAT | |
1746 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 1747 | bus_err: |
2bb5095a | 1748 | #endif |
b980a26d | 1749 | is_registered = false; |
e9f1373b DB |
1750 | bus_unregister(&i2c_bus_type); |
1751 | return retval; | |
1da177e4 LT |
1752 | } |
1753 | ||
1754 | static void __exit i2c_exit(void) | |
1755 | { | |
525e6fab OP |
1756 | if (IS_ENABLED(CONFIG_ACPI)) |
1757 | WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier)); | |
ea7513bb PA |
1758 | if (IS_ENABLED(CONFIG_OF_DYNAMIC)) |
1759 | WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier)); | |
e9f1373b | 1760 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
1761 | #ifdef CONFIG_I2C_COMPAT |
1762 | class_compat_unregister(i2c_adapter_compat_class); | |
1763 | #endif | |
1da177e4 | 1764 | bus_unregister(&i2c_bus_type); |
d9a83d62 | 1765 | tracepoint_synchronize_unregister(); |
1da177e4 LT |
1766 | } |
1767 | ||
a10f9e7c DB |
1768 | /* We must initialize early, because some subsystems register i2c drivers |
1769 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1770 | */ | |
1771 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1772 | module_exit(i2c_exit); |
1773 | ||
1774 | /* ---------------------------------------------------- | |
1775 | * the functional interface to the i2c busses. | |
1776 | * ---------------------------------------------------- | |
1777 | */ | |
1778 | ||
b7f62584 WS |
1779 | /* Check if val is exceeding the quirk IFF quirk is non 0 */ |
1780 | #define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk))) | |
1781 | ||
1782 | static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg) | |
1783 | { | |
1784 | dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n", | |
1785 | err_msg, msg->addr, msg->len, | |
1786 | msg->flags & I2C_M_RD ? "read" : "write"); | |
1787 | return -EOPNOTSUPP; | |
1788 | } | |
1789 | ||
1790 | static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
1791 | { | |
1792 | const struct i2c_adapter_quirks *q = adap->quirks; | |
1793 | int max_num = q->max_num_msgs, i; | |
1794 | bool do_len_check = true; | |
1795 | ||
1796 | if (q->flags & I2C_AQ_COMB) { | |
1797 | max_num = 2; | |
1798 | ||
1799 | /* special checks for combined messages */ | |
1800 | if (num == 2) { | |
1801 | if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD) | |
1802 | return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write"); | |
1803 | ||
1804 | if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD)) | |
1805 | return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read"); | |
1806 | ||
1807 | if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr) | |
1808 | return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr"); | |
1809 | ||
1810 | if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len)) | |
1811 | return i2c_quirk_error(adap, &msgs[0], "msg too long"); | |
1812 | ||
1813 | if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len)) | |
1814 | return i2c_quirk_error(adap, &msgs[1], "msg too long"); | |
1815 | ||
1816 | do_len_check = false; | |
1817 | } | |
1818 | } | |
1819 | ||
1820 | if (i2c_quirk_exceeded(num, max_num)) | |
1821 | return i2c_quirk_error(adap, &msgs[0], "too many messages"); | |
1822 | ||
1823 | for (i = 0; i < num; i++) { | |
1824 | u16 len = msgs[i].len; | |
1825 | ||
1826 | if (msgs[i].flags & I2C_M_RD) { | |
1827 | if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len)) | |
1828 | return i2c_quirk_error(adap, &msgs[i], "msg too long"); | |
1829 | } else { | |
1830 | if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len)) | |
1831 | return i2c_quirk_error(adap, &msgs[i], "msg too long"); | |
1832 | } | |
1833 | } | |
1834 | ||
1835 | return 0; | |
1836 | } | |
1837 | ||
b37d2a3a JD |
1838 | /** |
1839 | * __i2c_transfer - unlocked flavor of i2c_transfer | |
1840 | * @adap: Handle to I2C bus | |
1841 | * @msgs: One or more messages to execute before STOP is issued to | |
1842 | * terminate the operation; each message begins with a START. | |
1843 | * @num: Number of messages to be executed. | |
1844 | * | |
1845 | * Returns negative errno, else the number of messages executed. | |
1846 | * | |
1847 | * Adapter lock must be held when calling this function. No debug logging | |
1848 | * takes place. adap->algo->master_xfer existence isn't checked. | |
1849 | */ | |
1850 | int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
1851 | { | |
1852 | unsigned long orig_jiffies; | |
1853 | int ret, try; | |
1854 | ||
1eace834 AB |
1855 | if (WARN_ON(!msgs || num < 1)) |
1856 | return -EINVAL; | |
1857 | ||
b7f62584 WS |
1858 | if (adap->quirks && i2c_check_for_quirks(adap, msgs, num)) |
1859 | return -EOPNOTSUPP; | |
1860 | ||
50888b01 DB |
1861 | /* |
1862 | * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets | |
d9a83d62 DH |
1863 | * enabled. This is an efficient way of keeping the for-loop from |
1864 | * being executed when not needed. | |
1865 | */ | |
50888b01 | 1866 | if (static_branch_unlikely(&i2c_trace_msg_key)) { |
d9a83d62 DH |
1867 | int i; |
1868 | for (i = 0; i < num; i++) | |
1869 | if (msgs[i].flags & I2C_M_RD) | |
1870 | trace_i2c_read(adap, &msgs[i], i); | |
1871 | else | |
1872 | trace_i2c_write(adap, &msgs[i], i); | |
1873 | } | |
1874 | ||
b37d2a3a JD |
1875 | /* Retry automatically on arbitration loss */ |
1876 | orig_jiffies = jiffies; | |
1877 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
1878 | ret = adap->algo->master_xfer(adap, msgs, num); | |
1879 | if (ret != -EAGAIN) | |
1880 | break; | |
1881 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
1882 | break; | |
1883 | } | |
1884 | ||
50888b01 | 1885 | if (static_branch_unlikely(&i2c_trace_msg_key)) { |
d9a83d62 DH |
1886 | int i; |
1887 | for (i = 0; i < ret; i++) | |
1888 | if (msgs[i].flags & I2C_M_RD) | |
1889 | trace_i2c_reply(adap, &msgs[i], i); | |
4a3f7691 | 1890 | trace_i2c_result(adap, num, ret); |
d9a83d62 DH |
1891 | } |
1892 | ||
b37d2a3a JD |
1893 | return ret; |
1894 | } | |
1895 | EXPORT_SYMBOL(__i2c_transfer); | |
1896 | ||
a1cdedac DB |
1897 | /** |
1898 | * i2c_transfer - execute a single or combined I2C message | |
1899 | * @adap: Handle to I2C bus | |
1900 | * @msgs: One or more messages to execute before STOP is issued to | |
1901 | * terminate the operation; each message begins with a START. | |
1902 | * @num: Number of messages to be executed. | |
1903 | * | |
1904 | * Returns negative errno, else the number of messages executed. | |
1905 | * | |
1906 | * Note that there is no requirement that each message be sent to | |
1907 | * the same slave address, although that is the most common model. | |
1908 | */ | |
09b8ce0a | 1909 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 1910 | { |
b37d2a3a | 1911 | int ret; |
1da177e4 | 1912 | |
a1cdedac DB |
1913 | /* REVISIT the fault reporting model here is weak: |
1914 | * | |
1915 | * - When we get an error after receiving N bytes from a slave, | |
1916 | * there is no way to report "N". | |
1917 | * | |
1918 | * - When we get a NAK after transmitting N bytes to a slave, | |
1919 | * there is no way to report "N" ... or to let the master | |
1920 | * continue executing the rest of this combined message, if | |
1921 | * that's the appropriate response. | |
1922 | * | |
1923 | * - When for example "num" is two and we successfully complete | |
1924 | * the first message but get an error part way through the | |
1925 | * second, it's unclear whether that should be reported as | |
1926 | * one (discarding status on the second message) or errno | |
1927 | * (discarding status on the first one). | |
1928 | */ | |
1929 | ||
1da177e4 LT |
1930 | if (adap->algo->master_xfer) { |
1931 | #ifdef DEBUG | |
1932 | for (ret = 0; ret < num; ret++) { | |
b93d3d37 AS |
1933 | dev_dbg(&adap->dev, |
1934 | "master_xfer[%d] %c, addr=0x%02x, len=%d%s\n", | |
1935 | ret, (msgs[ret].flags & I2C_M_RD) ? 'R' : 'W', | |
1936 | msgs[ret].addr, msgs[ret].len, | |
209d27c3 | 1937 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); |
1da177e4 LT |
1938 | } |
1939 | #endif | |
1940 | ||
cea443a8 | 1941 | if (in_atomic() || irqs_disabled()) { |
fb79e09a | 1942 | ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT); |
cea443a8 MR |
1943 | if (!ret) |
1944 | /* I2C activity is ongoing. */ | |
1945 | return -EAGAIN; | |
1946 | } else { | |
8320f495 | 1947 | i2c_lock_bus(adap, I2C_LOCK_SEGMENT); |
cea443a8 MR |
1948 | } |
1949 | ||
b37d2a3a | 1950 | ret = __i2c_transfer(adap, msgs, num); |
8320f495 | 1951 | i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); |
1da177e4 LT |
1952 | |
1953 | return ret; | |
1954 | } else { | |
1955 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1956 | return -EOPNOTSUPP; |
1da177e4 LT |
1957 | } |
1958 | } | |
c0564606 | 1959 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1960 | |
a1cdedac | 1961 | /** |
8a91732b WS |
1962 | * i2c_transfer_buffer_flags - issue a single I2C message transferring data |
1963 | * to/from a buffer | |
a1cdedac | 1964 | * @client: Handle to slave device |
8a91732b WS |
1965 | * @buf: Where the data is stored |
1966 | * @count: How many bytes to transfer, must be less than 64k since msg.len is u16 | |
1967 | * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads | |
a1cdedac | 1968 | * |
8a91732b | 1969 | * Returns negative errno, or else the number of bytes transferred. |
a1cdedac | 1970 | */ |
8a91732b WS |
1971 | int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, |
1972 | int count, u16 flags) | |
1da177e4 | 1973 | { |
1da177e4 | 1974 | int ret; |
8a91732b WS |
1975 | struct i2c_msg msg = { |
1976 | .addr = client->addr, | |
1977 | .flags = flags | (client->flags & I2C_M_TEN), | |
1978 | .len = count, | |
1979 | .buf = buf, | |
1980 | }; | |
815f55f2 | 1981 | |
8a91732b | 1982 | ret = i2c_transfer(client->adapter, &msg, 1); |
815f55f2 | 1983 | |
834aa6f3 | 1984 | /* |
8a91732b WS |
1985 | * If everything went ok (i.e. 1 msg transferred), return #bytes |
1986 | * transferred, else error code. | |
834aa6f3 | 1987 | */ |
815f55f2 | 1988 | return (ret == 1) ? count : ret; |
1da177e4 | 1989 | } |
8a91732b | 1990 | EXPORT_SYMBOL(i2c_transfer_buffer_flags); |
1da177e4 | 1991 | |
dde67eb1 PR |
1992 | /** |
1993 | * i2c_get_device_id - get manufacturer, part id and die revision of a device | |
1994 | * @client: The device to query | |
1995 | * @id: The queried information | |
1996 | * | |
1997 | * Returns negative errno on error, zero on success. | |
1998 | */ | |
1999 | int i2c_get_device_id(const struct i2c_client *client, | |
2000 | struct i2c_device_identity *id) | |
2001 | { | |
2002 | struct i2c_adapter *adap = client->adapter; | |
2003 | union i2c_smbus_data raw_id; | |
2004 | int ret; | |
2005 | ||
2006 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) | |
2007 | return -EOPNOTSUPP; | |
2008 | ||
2009 | raw_id.block[0] = 3; | |
2010 | ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0, | |
2011 | I2C_SMBUS_READ, client->addr << 1, | |
2012 | I2C_SMBUS_I2C_BLOCK_DATA, &raw_id); | |
2013 | if (ret) | |
2014 | return ret; | |
2015 | ||
2016 | id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4); | |
2017 | id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3); | |
2018 | id->die_revision = raw_id.block[3] & 0x7; | |
2019 | return 0; | |
2020 | } | |
2021 | EXPORT_SYMBOL_GPL(i2c_get_device_id); | |
2022 | ||
1da177e4 LT |
2023 | /* ---------------------------------------------------- |
2024 | * the i2c address scanning function | |
2025 | * Will not work for 10-bit addresses! | |
2026 | * ---------------------------------------------------- | |
2027 | */ | |
1da177e4 | 2028 | |
63e4e802 JD |
2029 | /* |
2030 | * Legacy default probe function, mostly relevant for SMBus. The default | |
2031 | * probe method is a quick write, but it is known to corrupt the 24RF08 | |
2032 | * EEPROMs due to a state machine bug, and could also irreversibly | |
2033 | * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, | |
2034 | * we use a short byte read instead. Also, some bus drivers don't implement | |
2035 | * quick write, so we fallback to a byte read in that case too. | |
2036 | * On x86, there is another special case for FSC hardware monitoring chips, | |
2037 | * which want regular byte reads (address 0x73.) Fortunately, these are the | |
2038 | * only known chips using this I2C address on PC hardware. | |
2039 | * Returns 1 if probe succeeded, 0 if not. | |
2040 | */ | |
2041 | static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) | |
2042 | { | |
2043 | int err; | |
2044 | union i2c_smbus_data dummy; | |
2045 | ||
2046 | #ifdef CONFIG_X86 | |
2047 | if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) | |
2048 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) | |
2049 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
2050 | I2C_SMBUS_BYTE_DATA, &dummy); | |
2051 | else | |
2052 | #endif | |
8031d79b JD |
2053 | if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) |
2054 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) | |
63e4e802 JD |
2055 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, |
2056 | I2C_SMBUS_QUICK, NULL); | |
8031d79b JD |
2057 | else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) |
2058 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
2059 | I2C_SMBUS_BYTE, &dummy); | |
2060 | else { | |
d63a9e85 AL |
2061 | dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", |
2062 | addr); | |
8031d79b JD |
2063 | err = -EOPNOTSUPP; |
2064 | } | |
63e4e802 JD |
2065 | |
2066 | return err >= 0; | |
2067 | } | |
2068 | ||
ccfbbd08 | 2069 | static int i2c_detect_address(struct i2c_client *temp_client, |
4735c98f JD |
2070 | struct i2c_driver *driver) |
2071 | { | |
2072 | struct i2c_board_info info; | |
2073 | struct i2c_adapter *adapter = temp_client->adapter; | |
2074 | int addr = temp_client->addr; | |
2075 | int err; | |
2076 | ||
2077 | /* Make sure the address is valid */ | |
66be6056 | 2078 | err = i2c_check_7bit_addr_validity_strict(addr); |
656b8761 | 2079 | if (err) { |
4735c98f JD |
2080 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
2081 | addr); | |
656b8761 | 2082 | return err; |
4735c98f JD |
2083 | } |
2084 | ||
9bccc70a | 2085 | /* Skip if already in use (7 bit, no need to encode flags) */ |
3b5f794b | 2086 | if (i2c_check_addr_busy(adapter, addr)) |
4735c98f JD |
2087 | return 0; |
2088 | ||
ccfbbd08 | 2089 | /* Make sure there is something at this address */ |
63e4e802 JD |
2090 | if (!i2c_default_probe(adapter, addr)) |
2091 | return 0; | |
4735c98f JD |
2092 | |
2093 | /* Finally call the custom detection function */ | |
2094 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
2095 | info.addr = addr; | |
310ec792 | 2096 | err = driver->detect(temp_client, &info); |
4735c98f JD |
2097 | if (err) { |
2098 | /* -ENODEV is returned if the detection fails. We catch it | |
2099 | here as this isn't an error. */ | |
2100 | return err == -ENODEV ? 0 : err; | |
2101 | } | |
2102 | ||
2103 | /* Consistency check */ | |
2104 | if (info.type[0] == '\0') { | |
b93d3d37 AS |
2105 | dev_err(&adapter->dev, |
2106 | "%s detection function provided no name for 0x%x\n", | |
2107 | driver->driver.name, addr); | |
4735c98f JD |
2108 | } else { |
2109 | struct i2c_client *client; | |
2110 | ||
2111 | /* Detection succeeded, instantiate the device */ | |
0c176170 WS |
2112 | if (adapter->class & I2C_CLASS_DEPRECATED) |
2113 | dev_warn(&adapter->dev, | |
2114 | "This adapter will soon drop class based instantiation of devices. " | |
2115 | "Please make sure client 0x%02x gets instantiated by other means. " | |
2116 | "Check 'Documentation/i2c/instantiating-devices' for details.\n", | |
2117 | info.addr); | |
2118 | ||
4735c98f JD |
2119 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", |
2120 | info.type, info.addr); | |
2121 | client = i2c_new_device(adapter, &info); | |
2122 | if (client) | |
2123 | list_add_tail(&client->detected, &driver->clients); | |
2124 | else | |
2125 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
2126 | info.type, info.addr); | |
2127 | } | |
2128 | return 0; | |
2129 | } | |
2130 | ||
2131 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
2132 | { | |
c3813d6a | 2133 | const unsigned short *address_list; |
4735c98f JD |
2134 | struct i2c_client *temp_client; |
2135 | int i, err = 0; | |
2136 | int adap_id = i2c_adapter_id(adapter); | |
2137 | ||
c3813d6a JD |
2138 | address_list = driver->address_list; |
2139 | if (!driver->detect || !address_list) | |
4735c98f JD |
2140 | return 0; |
2141 | ||
45552272 WS |
2142 | /* Warn that the adapter lost class based instantiation */ |
2143 | if (adapter->class == I2C_CLASS_DEPRECATED) { | |
2144 | dev_dbg(&adapter->dev, | |
b93d3d37 AS |
2145 | "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. " |
2146 | "If you need it, check 'Documentation/i2c/instantiating-devices' for alternatives.\n", | |
45552272 WS |
2147 | driver->driver.name); |
2148 | return 0; | |
2149 | } | |
2150 | ||
51b54ba9 JD |
2151 | /* Stop here if the classes do not match */ |
2152 | if (!(adapter->class & driver->class)) | |
2153 | return 0; | |
2154 | ||
4735c98f JD |
2155 | /* Set up a temporary client to help detect callback */ |
2156 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
2157 | if (!temp_client) | |
2158 | return -ENOMEM; | |
2159 | temp_client->adapter = adapter; | |
2160 | ||
c3813d6a | 2161 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
b93d3d37 AS |
2162 | dev_dbg(&adapter->dev, |
2163 | "found normal entry for adapter %d, addr 0x%02x\n", | |
2164 | adap_id, address_list[i]); | |
c3813d6a | 2165 | temp_client->addr = address_list[i]; |
ccfbbd08 | 2166 | err = i2c_detect_address(temp_client, driver); |
51b54ba9 JD |
2167 | if (unlikely(err)) |
2168 | break; | |
4735c98f JD |
2169 | } |
2170 | ||
4735c98f JD |
2171 | kfree(temp_client); |
2172 | return err; | |
2173 | } | |
2174 | ||
d44f19d5 JD |
2175 | int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) |
2176 | { | |
2177 | return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
2178 | I2C_SMBUS_QUICK, NULL) >= 0; | |
2179 | } | |
2180 | EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); | |
2181 | ||
12b5053a JD |
2182 | struct i2c_client * |
2183 | i2c_new_probed_device(struct i2c_adapter *adap, | |
2184 | struct i2c_board_info *info, | |
9a94241a JD |
2185 | unsigned short const *addr_list, |
2186 | int (*probe)(struct i2c_adapter *, unsigned short addr)) | |
12b5053a JD |
2187 | { |
2188 | int i; | |
2189 | ||
8031d79b | 2190 | if (!probe) |
9a94241a | 2191 | probe = i2c_default_probe; |
12b5053a | 2192 | |
12b5053a JD |
2193 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
2194 | /* Check address validity */ | |
66be6056 | 2195 | if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) { |
b93d3d37 AS |
2196 | dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n", |
2197 | addr_list[i]); | |
12b5053a JD |
2198 | continue; |
2199 | } | |
2200 | ||
9bccc70a | 2201 | /* Check address availability (7 bit, no need to encode flags) */ |
3b5f794b | 2202 | if (i2c_check_addr_busy(adap, addr_list[i])) { |
b93d3d37 AS |
2203 | dev_dbg(&adap->dev, |
2204 | "Address 0x%02x already in use, not probing\n", | |
2205 | addr_list[i]); | |
12b5053a JD |
2206 | continue; |
2207 | } | |
2208 | ||
63e4e802 | 2209 | /* Test address responsiveness */ |
9a94241a | 2210 | if (probe(adap, addr_list[i])) |
63e4e802 | 2211 | break; |
12b5053a | 2212 | } |
12b5053a JD |
2213 | |
2214 | if (addr_list[i] == I2C_CLIENT_END) { | |
2215 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
2216 | return NULL; | |
2217 | } | |
2218 | ||
2219 | info->addr = addr_list[i]; | |
2220 | return i2c_new_device(adap, info); | |
2221 | } | |
2222 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
2223 | ||
d735b34d | 2224 | struct i2c_adapter *i2c_get_adapter(int nr) |
1da177e4 | 2225 | { |
1da177e4 | 2226 | struct i2c_adapter *adapter; |
438d6c2c | 2227 | |
caada32a | 2228 | mutex_lock(&core_lock); |
d735b34d | 2229 | adapter = idr_find(&i2c_adapter_idr, nr); |
611e12ea VZ |
2230 | if (!adapter) |
2231 | goto exit; | |
2232 | ||
2233 | if (try_module_get(adapter->owner)) | |
2234 | get_device(&adapter->dev); | |
2235 | else | |
a0920e10 MH |
2236 | adapter = NULL; |
2237 | ||
611e12ea | 2238 | exit: |
caada32a | 2239 | mutex_unlock(&core_lock); |
a0920e10 | 2240 | return adapter; |
1da177e4 | 2241 | } |
c0564606 | 2242 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
2243 | |
2244 | void i2c_put_adapter(struct i2c_adapter *adap) | |
2245 | { | |
611e12ea VZ |
2246 | if (!adap) |
2247 | return; | |
2248 | ||
2249 | put_device(&adap->dev); | |
2250 | module_put(adap->owner); | |
1da177e4 | 2251 | } |
c0564606 | 2252 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 | 2253 | |
e94bc5d1 WS |
2254 | /** |
2255 | * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg | |
2256 | * @msg: the message to be checked | |
2257 | * @threshold: the minimum number of bytes for which using DMA makes sense | |
2258 | * | |
2259 | * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO. | |
2260 | * Or a valid pointer to be used with DMA. After use, release it by | |
2261 | * calling i2c_release_dma_safe_msg_buf(). | |
2262 | * | |
2263 | * This function must only be called from process context! | |
2264 | */ | |
2265 | u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold) | |
2266 | { | |
2267 | if (msg->len < threshold) | |
2268 | return NULL; | |
2269 | ||
2270 | if (msg->flags & I2C_M_DMA_SAFE) | |
2271 | return msg->buf; | |
2272 | ||
2273 | pr_debug("using bounce buffer for addr=0x%02x, len=%d\n", | |
2274 | msg->addr, msg->len); | |
2275 | ||
2276 | if (msg->flags & I2C_M_RD) | |
2277 | return kzalloc(msg->len, GFP_KERNEL); | |
2278 | else | |
2279 | return kmemdup(msg->buf, msg->len, GFP_KERNEL); | |
2280 | } | |
2281 | EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf); | |
2282 | ||
2283 | /** | |
2284 | * i2c_release_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg | |
2285 | * @msg: the message to be synced with | |
2286 | * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL. | |
2287 | */ | |
2288 | void i2c_release_dma_safe_msg_buf(struct i2c_msg *msg, u8 *buf) | |
2289 | { | |
2290 | if (!buf || buf == msg->buf) | |
2291 | return; | |
2292 | ||
2293 | if (msg->flags & I2C_M_RD) | |
2294 | memcpy(msg->buf, buf, msg->len); | |
2295 | ||
2296 | kfree(buf); | |
2297 | } | |
2298 | EXPORT_SYMBOL_GPL(i2c_release_dma_safe_msg_buf); | |
2299 | ||
1da177e4 LT |
2300 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); |
2301 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
2302 | MODULE_LICENSE("GPL"); |