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Commit | Line | Data |
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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); | |
201 | ndelay(RECOVERY_NDELAY); | |
202 | } | |
203 | ||
1f35b865 CF |
204 | /* check if recovery actually succeeded */ |
205 | if (bri->get_sda && !bri->get_sda(adap)) | |
206 | ret = -EBUSY; | |
207 | ||
2806e6ad WS |
208 | /* If all went well, send STOP for a sane bus state. */ |
209 | if (ret == 0 && bri->set_sda) { | |
210 | bri->set_scl(adap, 0); | |
211 | ndelay(RECOVERY_NDELAY / 2); | |
212 | bri->set_sda(adap, 0); | |
213 | ndelay(RECOVERY_NDELAY / 2); | |
214 | bri->set_scl(adap, 1); | |
215 | ndelay(RECOVERY_NDELAY / 2); | |
216 | bri->set_sda(adap, 1); | |
217 | ndelay(RECOVERY_NDELAY / 2); | |
218 | } | |
219 | ||
5f9296ba | 220 | if (bri->unprepare_recovery) |
2b2190a3 | 221 | bri->unprepare_recovery(adap); |
5f9296ba VK |
222 | |
223 | return ret; | |
224 | } | |
c1c21f4e | 225 | EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery); |
5f9296ba | 226 | |
5f9296ba VK |
227 | int i2c_recover_bus(struct i2c_adapter *adap) |
228 | { | |
229 | if (!adap->bus_recovery_info) | |
230 | return -EOPNOTSUPP; | |
231 | ||
232 | dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); | |
233 | return adap->bus_recovery_info->recover_bus(adap); | |
234 | } | |
c1c21f4e | 235 | EXPORT_SYMBOL_GPL(i2c_recover_bus); |
5f9296ba | 236 | |
d3b11d83 WS |
237 | static void i2c_init_recovery(struct i2c_adapter *adap) |
238 | { | |
239 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; | |
240 | char *err_str; | |
241 | ||
242 | if (!bri) | |
243 | return; | |
244 | ||
245 | if (!bri->recover_bus) { | |
246 | err_str = "no recover_bus() found"; | |
247 | goto err; | |
248 | } | |
249 | ||
3991c5c8 | 250 | if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) { |
d3b11d83 WS |
251 | bri->get_scl = get_scl_gpio_value; |
252 | bri->set_scl = set_scl_gpio_value; | |
8092178f | 253 | if (bri->sda_gpiod) { |
3991c5c8 | 254 | bri->get_sda = get_sda_gpio_value; |
8092178f WS |
255 | /* FIXME: add proper flag instead of '0' once available */ |
256 | if (gpiod_get_direction(bri->sda_gpiod) == 0) | |
257 | bri->set_sda = set_sda_gpio_value; | |
258 | } | |
3991c5c8 PR |
259 | return; |
260 | } | |
261 | ||
e1eb7d28 | 262 | if (bri->recover_bus == i2c_generic_scl_recovery) { |
d3b11d83 WS |
263 | /* Generic SCL recovery */ |
264 | if (!bri->set_scl || !bri->get_scl) { | |
265 | err_str = "no {get|set}_scl() found"; | |
266 | goto err; | |
267 | } | |
268 | } | |
269 | ||
270 | return; | |
271 | err: | |
272 | dev_err(&adap->dev, "Not using recovery: %s\n", err_str); | |
273 | adap->bus_recovery_info = NULL; | |
274 | } | |
275 | ||
4d5538f5 BT |
276 | static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client) |
277 | { | |
278 | struct i2c_adapter *adap = client->adapter; | |
279 | unsigned int irq; | |
280 | ||
281 | if (!adap->host_notify_domain) | |
282 | return -ENXIO; | |
283 | ||
284 | if (client->flags & I2C_CLIENT_TEN) | |
285 | return -EINVAL; | |
286 | ||
287 | irq = irq_find_mapping(adap->host_notify_domain, client->addr); | |
288 | if (!irq) | |
289 | irq = irq_create_mapping(adap->host_notify_domain, | |
290 | client->addr); | |
291 | ||
292 | return irq > 0 ? irq : -ENXIO; | |
293 | } | |
294 | ||
f37dd80a | 295 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 296 | { |
51298d12 JD |
297 | struct i2c_client *client = i2c_verify_client(dev); |
298 | struct i2c_driver *driver; | |
50c3304a | 299 | int status; |
7b4fbc50 | 300 | |
51298d12 JD |
301 | if (!client) |
302 | return 0; | |
303 | ||
d1d84bb9 HG |
304 | driver = to_i2c_driver(dev->driver); |
305 | ||
306 | if (!client->irq && !driver->disable_i2c_core_irq_mapping) { | |
845c8770 MW |
307 | int irq = -ENOENT; |
308 | ||
331c3425 DT |
309 | if (client->flags & I2C_CLIENT_HOST_NOTIFY) { |
310 | dev_dbg(dev, "Using Host Notify IRQ\n"); | |
311 | irq = i2c_smbus_host_notify_to_irq(client); | |
312 | } else if (dev->of_node) { | |
3fffd128 DT |
313 | irq = of_irq_get_byname(dev->of_node, "irq"); |
314 | if (irq == -EINVAL || irq == -ENODATA) | |
315 | irq = of_irq_get(dev->of_node, 0); | |
316 | } else if (ACPI_COMPANION(dev)) { | |
845c8770 | 317 | irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0); |
3fffd128 | 318 | } |
6f34be74 | 319 | if (irq == -EPROBE_DEFER) |
2fd36c55 | 320 | return irq; |
331c3425 | 321 | |
6f34be74 GU |
322 | if (irq < 0) |
323 | irq = 0; | |
2fd36c55 LP |
324 | |
325 | client->irq = irq; | |
326 | } | |
327 | ||
da10c06a | 328 | /* |
f4b17a14 JMC |
329 | * An I2C ID table is not mandatory, if and only if, a suitable OF |
330 | * or ACPI ID table is supplied for the probing device. | |
da10c06a LJ |
331 | */ |
332 | if (!driver->id_table && | |
c64ffff7 | 333 | !i2c_acpi_match_device(dev->driver->acpi_match_table, client) && |
da10c06a | 334 | !i2c_of_match_device(dev->driver->of_match_table, client)) |
7b4fbc50 | 335 | return -ENODEV; |
0acc2b32 | 336 | |
3fffd128 DT |
337 | if (client->flags & I2C_CLIENT_WAKE) { |
338 | int wakeirq = -ENOENT; | |
339 | ||
340 | if (dev->of_node) { | |
341 | wakeirq = of_irq_get_byname(dev->of_node, "wakeup"); | |
342 | if (wakeirq == -EPROBE_DEFER) | |
343 | return wakeirq; | |
344 | } | |
345 | ||
346 | device_init_wakeup(&client->dev, true); | |
347 | ||
348 | if (wakeirq > 0 && wakeirq != client->irq) | |
349 | status = dev_pm_set_dedicated_wake_irq(dev, wakeirq); | |
350 | else if (client->irq > 0) | |
c18fba23 | 351 | status = dev_pm_set_wake_irq(dev, client->irq); |
3fffd128 DT |
352 | else |
353 | status = 0; | |
354 | ||
355 | if (status) | |
b93d3d37 | 356 | dev_warn(&client->dev, "failed to set up wakeup irq\n"); |
3fffd128 DT |
357 | } |
358 | ||
7b4fbc50 | 359 | dev_dbg(dev, "probe\n"); |
d2653e92 | 360 | |
86be408b SN |
361 | status = of_clk_set_defaults(dev->of_node, false); |
362 | if (status < 0) | |
3fffd128 | 363 | goto err_clear_wakeup_irq; |
86be408b | 364 | |
e09b0d4e | 365 | status = dev_pm_domain_attach(&client->dev, true); |
e6a20b6c | 366 | if (status) |
74cedd30 KB |
367 | goto err_clear_wakeup_irq; |
368 | ||
b8a1a4cd LJ |
369 | /* |
370 | * When there are no more users of probe(), | |
371 | * rename probe_new to probe. | |
372 | */ | |
373 | if (driver->probe_new) | |
374 | status = driver->probe_new(client); | |
375 | else if (driver->probe) | |
376 | status = driver->probe(client, | |
377 | i2c_match_id(driver->id_table, client)); | |
378 | else | |
379 | status = -EINVAL; | |
380 | ||
74cedd30 KB |
381 | if (status) |
382 | goto err_detach_pm_domain; | |
72fa818e | 383 | |
3fffd128 DT |
384 | return 0; |
385 | ||
386 | err_detach_pm_domain: | |
387 | dev_pm_domain_detach(&client->dev, true); | |
388 | err_clear_wakeup_irq: | |
389 | dev_pm_clear_wake_irq(&client->dev); | |
390 | device_init_wakeup(&client->dev, false); | |
50c3304a | 391 | return status; |
f37dd80a | 392 | } |
1da177e4 | 393 | |
f37dd80a DB |
394 | static int i2c_device_remove(struct device *dev) |
395 | { | |
51298d12 | 396 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 | 397 | struct i2c_driver *driver; |
72fa818e | 398 | int status = 0; |
a1d9e6e4 | 399 | |
51298d12 | 400 | if (!client || !dev->driver) |
a1d9e6e4 DB |
401 | return 0; |
402 | ||
403 | driver = to_i2c_driver(dev->driver); | |
404 | if (driver->remove) { | |
405 | dev_dbg(dev, "remove\n"); | |
406 | status = driver->remove(client); | |
a1d9e6e4 | 407 | } |
72fa818e | 408 | |
e09b0d4e | 409 | dev_pm_domain_detach(&client->dev, true); |
3fffd128 DT |
410 | |
411 | dev_pm_clear_wake_irq(&client->dev); | |
412 | device_init_wakeup(&client->dev, false); | |
413 | ||
a1d9e6e4 | 414 | return status; |
1da177e4 LT |
415 | } |
416 | ||
f37dd80a | 417 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 418 | { |
51298d12 | 419 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
420 | struct i2c_driver *driver; |
421 | ||
51298d12 | 422 | if (!client || !dev->driver) |
f37dd80a DB |
423 | return; |
424 | driver = to_i2c_driver(dev->driver); | |
425 | if (driver->shutdown) | |
51298d12 | 426 | driver->shutdown(client); |
1da177e4 LT |
427 | } |
428 | ||
9c1600ed DB |
429 | static void i2c_client_dev_release(struct device *dev) |
430 | { | |
431 | kfree(to_i2c_client(dev)); | |
432 | } | |
433 | ||
09b8ce0a | 434 | static ssize_t |
4f8cf824 | 435 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 436 | { |
4f8cf824 JD |
437 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
438 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 | 439 | } |
a5eb71b2 | 440 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
7b4fbc50 | 441 | |
09b8ce0a ZX |
442 | static ssize_t |
443 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
444 | { |
445 | struct i2c_client *client = to_i2c_client(dev); | |
8c4ff6d0 ZR |
446 | int len; |
447 | ||
af503716 JMC |
448 | len = of_device_modalias(dev, buf, PAGE_SIZE); |
449 | if (len != -ENODEV) | |
450 | return len; | |
451 | ||
8c4ff6d0 ZR |
452 | len = acpi_device_modalias(dev, buf, PAGE_SIZE -1); |
453 | if (len != -ENODEV) | |
454 | return len; | |
455 | ||
eb8a7908 | 456 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 | 457 | } |
51298d12 JD |
458 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
459 | ||
460 | static struct attribute *i2c_dev_attrs[] = { | |
461 | &dev_attr_name.attr, | |
7b4fbc50 | 462 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
463 | &dev_attr_modalias.attr, |
464 | NULL | |
465 | }; | |
a5eb71b2 | 466 | ATTRIBUTE_GROUPS(i2c_dev); |
54067ee2 | 467 | |
e9ca9eb9 | 468 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
469 | .name = "i2c", |
470 | .match = i2c_device_match, | |
471 | .probe = i2c_device_probe, | |
472 | .remove = i2c_device_remove, | |
473 | .shutdown = i2c_device_shutdown, | |
b864c7d5 | 474 | }; |
e9ca9eb9 | 475 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 476 | |
00a06c22 | 477 | struct device_type i2c_client_type = { |
a5eb71b2 | 478 | .groups = i2c_dev_groups, |
51298d12 JD |
479 | .uevent = i2c_device_uevent, |
480 | .release = i2c_client_dev_release, | |
481 | }; | |
00a06c22 | 482 | EXPORT_SYMBOL_GPL(i2c_client_type); |
51298d12 | 483 | |
9b766b81 DB |
484 | |
485 | /** | |
486 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
487 | * @dev: device, probably from some driver model iterator | |
488 | * | |
489 | * When traversing the driver model tree, perhaps using driver model | |
490 | * iterators like @device_for_each_child(), you can't assume very much | |
491 | * about the nodes you find. Use this function to avoid oopses caused | |
492 | * by wrongly treating some non-I2C device as an i2c_client. | |
493 | */ | |
494 | struct i2c_client *i2c_verify_client(struct device *dev) | |
495 | { | |
51298d12 | 496 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
497 | ? to_i2c_client(dev) |
498 | : NULL; | |
499 | } | |
500 | EXPORT_SYMBOL(i2c_verify_client); | |
501 | ||
502 | ||
da899f55 WS |
503 | /* Return a unique address which takes the flags of the client into account */ |
504 | static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client) | |
505 | { | |
506 | unsigned short addr = client->addr; | |
507 | ||
508 | /* For some client flags, add an arbitrary offset to avoid collisions */ | |
509 | if (client->flags & I2C_CLIENT_TEN) | |
510 | addr |= I2C_ADDR_OFFSET_TEN_BIT; | |
511 | ||
512 | if (client->flags & I2C_CLIENT_SLAVE) | |
513 | addr |= I2C_ADDR_OFFSET_SLAVE; | |
514 | ||
515 | return addr; | |
516 | } | |
517 | ||
3a89db5f | 518 | /* This is a permissive address validity check, I2C address map constraints |
25985edc | 519 | * are purposely not enforced, except for the general call address. */ |
398432ed | 520 | static int i2c_check_addr_validity(unsigned int addr, unsigned short flags) |
3a89db5f | 521 | { |
c4019b70 | 522 | if (flags & I2C_CLIENT_TEN) { |
3a89db5f | 523 | /* 10-bit address, all values are valid */ |
c4019b70 | 524 | if (addr > 0x3ff) |
3a89db5f JD |
525 | return -EINVAL; |
526 | } else { | |
527 | /* 7-bit address, reject the general call address */ | |
c4019b70 | 528 | if (addr == 0x00 || addr > 0x7f) |
3a89db5f JD |
529 | return -EINVAL; |
530 | } | |
531 | return 0; | |
532 | } | |
533 | ||
656b8761 JD |
534 | /* And this is a strict address validity check, used when probing. If a |
535 | * device uses a reserved address, then it shouldn't be probed. 7-bit | |
536 | * addressing is assumed, 10-bit address devices are rare and should be | |
537 | * explicitly enumerated. */ | |
e4991ecd | 538 | int i2c_check_7bit_addr_validity_strict(unsigned short addr) |
656b8761 JD |
539 | { |
540 | /* | |
541 | * Reserved addresses per I2C specification: | |
542 | * 0x00 General call address / START byte | |
543 | * 0x01 CBUS address | |
544 | * 0x02 Reserved for different bus format | |
545 | * 0x03 Reserved for future purposes | |
546 | * 0x04-0x07 Hs-mode master code | |
547 | * 0x78-0x7b 10-bit slave addressing | |
548 | * 0x7c-0x7f Reserved for future purposes | |
549 | */ | |
550 | if (addr < 0x08 || addr > 0x77) | |
551 | return -EINVAL; | |
552 | return 0; | |
553 | } | |
554 | ||
3b5f794b JD |
555 | static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
556 | { | |
557 | struct i2c_client *client = i2c_verify_client(dev); | |
558 | int addr = *(int *)addrp; | |
559 | ||
9bccc70a | 560 | if (client && i2c_encode_flags_to_addr(client) == addr) |
3b5f794b JD |
561 | return -EBUSY; |
562 | return 0; | |
563 | } | |
564 | ||
0826374b ML |
565 | /* walk up mux tree */ |
566 | static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
567 | { | |
97cc4d49 | 568 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
569 | int result; |
570 | ||
571 | result = device_for_each_child(&adapter->dev, &addr, | |
572 | __i2c_check_addr_busy); | |
573 | ||
97cc4d49 JD |
574 | if (!result && parent) |
575 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
576 | |
577 | return result; | |
578 | } | |
579 | ||
580 | /* recurse down mux tree */ | |
581 | static int i2c_check_mux_children(struct device *dev, void *addrp) | |
582 | { | |
583 | int result; | |
584 | ||
585 | if (dev->type == &i2c_adapter_type) | |
586 | result = device_for_each_child(dev, addrp, | |
587 | i2c_check_mux_children); | |
588 | else | |
589 | result = __i2c_check_addr_busy(dev, addrp); | |
590 | ||
591 | return result; | |
592 | } | |
593 | ||
3b5f794b JD |
594 | static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) |
595 | { | |
97cc4d49 | 596 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
597 | int result = 0; |
598 | ||
97cc4d49 JD |
599 | if (parent) |
600 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
601 | |
602 | if (!result) | |
603 | result = device_for_each_child(&adapter->dev, &addr, | |
604 | i2c_check_mux_children); | |
605 | ||
606 | return result; | |
3b5f794b JD |
607 | } |
608 | ||
fe61e07e | 609 | /** |
8320f495 | 610 | * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment |
fe61e07e | 611 | * @adapter: Target I2C bus segment |
8320f495 PR |
612 | * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT |
613 | * locks only this branch in the adapter tree | |
fe61e07e | 614 | */ |
8320f495 PR |
615 | static void i2c_adapter_lock_bus(struct i2c_adapter *adapter, |
616 | unsigned int flags) | |
fe61e07e | 617 | { |
fa96f0cb | 618 | rt_mutex_lock(&adapter->bus_lock); |
fe61e07e | 619 | } |
fe61e07e JD |
620 | |
621 | /** | |
8320f495 | 622 | * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment |
fe61e07e | 623 | * @adapter: Target I2C bus segment |
8320f495 PR |
624 | * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT |
625 | * trylocks only this branch in the adapter tree | |
fe61e07e | 626 | */ |
8320f495 PR |
627 | static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter, |
628 | unsigned int flags) | |
fe61e07e | 629 | { |
fa96f0cb | 630 | return rt_mutex_trylock(&adapter->bus_lock); |
fe61e07e JD |
631 | } |
632 | ||
633 | /** | |
8320f495 | 634 | * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment |
fe61e07e | 635 | * @adapter: Target I2C bus segment |
8320f495 PR |
636 | * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT |
637 | * unlocks only this branch in the adapter tree | |
fe61e07e | 638 | */ |
8320f495 PR |
639 | static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter, |
640 | unsigned int flags) | |
fe61e07e | 641 | { |
fa96f0cb | 642 | rt_mutex_unlock(&adapter->bus_lock); |
fe61e07e | 643 | } |
fe61e07e | 644 | |
70762abb | 645 | static void i2c_dev_set_name(struct i2c_adapter *adap, |
728fe6ce HG |
646 | struct i2c_client *client, |
647 | struct i2c_board_info const *info) | |
70762abb JN |
648 | { |
649 | struct acpi_device *adev = ACPI_COMPANION(&client->dev); | |
650 | ||
728fe6ce HG |
651 | if (info && info->dev_name) { |
652 | dev_set_name(&client->dev, "i2c-%s", info->dev_name); | |
653 | return; | |
654 | } | |
655 | ||
70762abb JN |
656 | if (adev) { |
657 | dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); | |
658 | return; | |
659 | } | |
660 | ||
70762abb | 661 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), |
da899f55 | 662 | i2c_encode_flags_to_addr(client)); |
70762abb JN |
663 | } |
664 | ||
4124c4eb DT |
665 | static int i2c_dev_irq_from_resources(const struct resource *resources, |
666 | unsigned int num_resources) | |
667 | { | |
668 | struct irq_data *irqd; | |
669 | int i; | |
670 | ||
671 | for (i = 0; i < num_resources; i++) { | |
672 | const struct resource *r = &resources[i]; | |
673 | ||
674 | if (resource_type(r) != IORESOURCE_IRQ) | |
675 | continue; | |
676 | ||
677 | if (r->flags & IORESOURCE_BITS) { | |
678 | irqd = irq_get_irq_data(r->start); | |
679 | if (!irqd) | |
680 | break; | |
681 | ||
682 | irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); | |
683 | } | |
684 | ||
685 | return r->start; | |
686 | } | |
687 | ||
688 | return 0; | |
689 | } | |
690 | ||
9c1600ed | 691 | /** |
f8a227e8 | 692 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
693 | * @adap: the adapter managing the device |
694 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 695 | * Context: can sleep |
9c1600ed | 696 | * |
f8a227e8 JD |
697 | * Create an i2c device. Binding is handled through driver model |
698 | * probe()/remove() methods. A driver may be bound to this device when we | |
699 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
700 | * load the driver module). This call is not appropriate for use by mainboard | |
701 | * initialization logic, which usually runs during an arch_initcall() long | |
702 | * before any i2c_adapter could exist. | |
9c1600ed DB |
703 | * |
704 | * This returns the new i2c client, which may be saved for later use with | |
705 | * i2c_unregister_device(); or NULL to indicate an error. | |
706 | */ | |
707 | struct i2c_client * | |
708 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
709 | { | |
710 | struct i2c_client *client; | |
711 | int status; | |
712 | ||
713 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
714 | if (!client) | |
715 | return NULL; | |
716 | ||
717 | client->adapter = adap; | |
718 | ||
719 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 720 | |
11f1f2af AV |
721 | if (info->archdata) |
722 | client->dev.archdata = *info->archdata; | |
723 | ||
ee35425c | 724 | client->flags = info->flags; |
9c1600ed | 725 | client->addr = info->addr; |
4124c4eb | 726 | |
9c1600ed | 727 | client->irq = info->irq; |
4124c4eb DT |
728 | if (!client->irq) |
729 | client->irq = i2c_dev_irq_from_resources(info->resources, | |
730 | info->num_resources); | |
9c1600ed | 731 | |
9c1600ed DB |
732 | strlcpy(client->name, info->type, sizeof(client->name)); |
733 | ||
c4019b70 | 734 | status = i2c_check_addr_validity(client->addr, client->flags); |
3a89db5f JD |
735 | if (status) { |
736 | dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", | |
737 | client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); | |
738 | goto out_err_silent; | |
739 | } | |
740 | ||
f8a227e8 | 741 | /* Check for address business */ |
9bccc70a | 742 | status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client)); |
f8a227e8 JD |
743 | if (status) |
744 | goto out_err; | |
745 | ||
746 | client->dev.parent = &client->adapter->dev; | |
747 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 748 | client->dev.type = &i2c_client_type; |
d12d42f7 | 749 | client->dev.of_node = info->of_node; |
ce793486 | 750 | client->dev.fwnode = info->fwnode; |
f8a227e8 | 751 | |
728fe6ce | 752 | i2c_dev_set_name(adap, client, info); |
d3e1b617 DT |
753 | |
754 | if (info->properties) { | |
755 | status = device_add_properties(&client->dev, info->properties); | |
756 | if (status) { | |
757 | dev_err(&adap->dev, | |
758 | "Failed to add properties to client %s: %d\n", | |
759 | client->name, status); | |
760 | goto out_err; | |
761 | } | |
762 | } | |
763 | ||
f8a227e8 JD |
764 | status = device_register(&client->dev); |
765 | if (status) | |
d3e1b617 | 766 | goto out_free_props; |
f8a227e8 | 767 | |
f8a227e8 JD |
768 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
769 | client->name, dev_name(&client->dev)); | |
770 | ||
9c1600ed | 771 | return client; |
f8a227e8 | 772 | |
d3e1b617 DT |
773 | out_free_props: |
774 | if (info->properties) | |
775 | device_remove_properties(&client->dev); | |
f8a227e8 | 776 | out_err: |
b93d3d37 AS |
777 | dev_err(&adap->dev, |
778 | "Failed to register i2c client %s at 0x%02x (%d)\n", | |
779 | client->name, client->addr, status); | |
3a89db5f | 780 | out_err_silent: |
f8a227e8 JD |
781 | kfree(client); |
782 | return NULL; | |
9c1600ed DB |
783 | } |
784 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
785 | ||
786 | ||
787 | /** | |
788 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
789 | * @client: value returned from i2c_new_device() | |
d64f73be | 790 | * Context: can sleep |
9c1600ed DB |
791 | */ |
792 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 793 | { |
7b43dd19 AS |
794 | if (!client) |
795 | return; | |
e0638fa4 LW |
796 | |
797 | if (client->dev.of_node) { | |
4f001fd3 | 798 | of_node_clear_flag(client->dev.of_node, OF_POPULATED); |
e0638fa4 LW |
799 | of_node_put(client->dev.of_node); |
800 | } | |
801 | ||
525e6fab OP |
802 | if (ACPI_COMPANION(&client->dev)) |
803 | acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev)); | |
a1d9e6e4 DB |
804 | device_unregister(&client->dev); |
805 | } | |
9c1600ed | 806 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
807 | |
808 | ||
60b129d7 JD |
809 | static const struct i2c_device_id dummy_id[] = { |
810 | { "dummy", 0 }, | |
811 | { }, | |
812 | }; | |
813 | ||
d2653e92 JD |
814 | static int dummy_probe(struct i2c_client *client, |
815 | const struct i2c_device_id *id) | |
816 | { | |
817 | return 0; | |
818 | } | |
819 | ||
820 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
821 | { |
822 | return 0; | |
823 | } | |
824 | ||
825 | static struct i2c_driver dummy_driver = { | |
826 | .driver.name = "dummy", | |
d2653e92 JD |
827 | .probe = dummy_probe, |
828 | .remove = dummy_remove, | |
60b129d7 | 829 | .id_table = dummy_id, |
e9f1373b DB |
830 | }; |
831 | ||
832 | /** | |
833 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
834 | * @adapter: the adapter managing the device | |
835 | * @address: seven bit address to be used | |
e9f1373b DB |
836 | * Context: can sleep |
837 | * | |
838 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
839 | * with devices that consume multiple addresses. Examples of such chips | |
840 | * include various EEPROMS (like 24c04 and 24c08 models). | |
841 | * | |
842 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
843 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
844 | * And second, this prevents the specified address from being bound to a | |
845 | * different driver. | |
846 | * | |
847 | * This returns the new i2c client, which should be saved for later use with | |
848 | * i2c_unregister_device(); or NULL to indicate an error. | |
849 | */ | |
09b8ce0a | 850 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
851 | { |
852 | struct i2c_board_info info = { | |
60b129d7 | 853 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
854 | }; |
855 | ||
e9f1373b DB |
856 | return i2c_new_device(adapter, &info); |
857 | } | |
858 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
859 | ||
0f614d83 JMH |
860 | /** |
861 | * i2c_new_secondary_device - Helper to get the instantiated secondary address | |
862 | * and create the associated device | |
863 | * @client: Handle to the primary client | |
864 | * @name: Handle to specify which secondary address to get | |
865 | * @default_addr: Used as a fallback if no secondary address was specified | |
866 | * Context: can sleep | |
867 | * | |
868 | * I2C clients can be composed of multiple I2C slaves bound together in a single | |
869 | * component. The I2C client driver then binds to the master I2C slave and needs | |
870 | * to create I2C dummy clients to communicate with all the other slaves. | |
871 | * | |
872 | * This function creates and returns an I2C dummy client whose I2C address is | |
873 | * retrieved from the platform firmware based on the given slave name. If no | |
874 | * address is specified by the firmware default_addr is used. | |
875 | * | |
876 | * On DT-based platforms the address is retrieved from the "reg" property entry | |
877 | * cell whose "reg-names" value matches the slave name. | |
878 | * | |
879 | * This returns the new i2c client, which should be saved for later use with | |
880 | * i2c_unregister_device(); or NULL to indicate an error. | |
881 | */ | |
882 | struct i2c_client *i2c_new_secondary_device(struct i2c_client *client, | |
883 | const char *name, | |
884 | u16 default_addr) | |
885 | { | |
886 | struct device_node *np = client->dev.of_node; | |
887 | u32 addr = default_addr; | |
888 | int i; | |
889 | ||
890 | if (np) { | |
891 | i = of_property_match_string(np, "reg-names", name); | |
892 | if (i >= 0) | |
893 | of_property_read_u32_index(np, "reg", i, &addr); | |
894 | } | |
895 | ||
896 | dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr); | |
897 | return i2c_new_dummy(client->adapter, addr); | |
898 | } | |
899 | EXPORT_SYMBOL_GPL(i2c_new_secondary_device); | |
900 | ||
f37dd80a DB |
901 | /* ------------------------------------------------------------------------- */ |
902 | ||
16ffadfc DB |
903 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
904 | ||
83eaaed0 | 905 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 906 | { |
ef2c8321 | 907 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
908 | complete(&adap->dev_released); |
909 | } | |
910 | ||
8dd1fe15 | 911 | unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) |
390946b1 JD |
912 | { |
913 | unsigned int depth = 0; | |
914 | ||
915 | while ((adapter = i2c_parent_is_i2c_adapter(adapter))) | |
916 | depth++; | |
917 | ||
2771dc34 BG |
918 | WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES, |
919 | "adapter depth exceeds lockdep subclass limit\n"); | |
920 | ||
390946b1 JD |
921 | return depth; |
922 | } | |
8dd1fe15 | 923 | EXPORT_SYMBOL_GPL(i2c_adapter_depth); |
390946b1 | 924 | |
99cd8e25 JD |
925 | /* |
926 | * Let users instantiate I2C devices through sysfs. This can be used when | |
927 | * platform initialization code doesn't contain the proper data for | |
928 | * whatever reason. Also useful for drivers that do device detection and | |
929 | * detection fails, either because the device uses an unexpected address, | |
930 | * or this is a compatible device with different ID register values. | |
931 | * | |
932 | * Parameter checking may look overzealous, but we really don't want | |
933 | * the user to provide incorrect parameters. | |
934 | */ | |
935 | static ssize_t | |
936 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
937 | const char *buf, size_t count) | |
938 | { | |
939 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
940 | struct i2c_board_info info; | |
941 | struct i2c_client *client; | |
942 | char *blank, end; | |
943 | int res; | |
944 | ||
99cd8e25 JD |
945 | memset(&info, 0, sizeof(struct i2c_board_info)); |
946 | ||
947 | blank = strchr(buf, ' '); | |
948 | if (!blank) { | |
949 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
950 | return -EINVAL; | |
951 | } | |
952 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
953 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
954 | return -EINVAL; | |
955 | } | |
956 | memcpy(info.type, buf, blank - buf); | |
957 | ||
958 | /* Parse remaining parameters, reject extra parameters */ | |
959 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
960 | if (res < 1) { | |
961 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
962 | return -EINVAL; | |
963 | } | |
964 | if (res > 1 && end != '\n') { | |
965 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
966 | return -EINVAL; | |
967 | } | |
968 | ||
cfa0327b WS |
969 | if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) { |
970 | info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT; | |
971 | info.flags |= I2C_CLIENT_TEN; | |
972 | } | |
973 | ||
974 | if (info.addr & I2C_ADDR_OFFSET_SLAVE) { | |
975 | info.addr &= ~I2C_ADDR_OFFSET_SLAVE; | |
976 | info.flags |= I2C_CLIENT_SLAVE; | |
977 | } | |
978 | ||
99cd8e25 JD |
979 | client = i2c_new_device(adap, &info); |
980 | if (!client) | |
3a89db5f | 981 | return -EINVAL; |
99cd8e25 JD |
982 | |
983 | /* Keep track of the added device */ | |
dafc50d1 | 984 | mutex_lock(&adap->userspace_clients_lock); |
6629dcff | 985 | list_add_tail(&client->detected, &adap->userspace_clients); |
dafc50d1 | 986 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
987 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
988 | info.type, info.addr); | |
989 | ||
990 | return count; | |
991 | } | |
a5eb71b2 | 992 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
99cd8e25 JD |
993 | |
994 | /* | |
995 | * And of course let the users delete the devices they instantiated, if | |
996 | * they got it wrong. This interface can only be used to delete devices | |
997 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
998 | * don't delete devices to which some kernel code still has references. | |
999 | * | |
1000 | * Parameter checking may look overzealous, but we really don't want | |
1001 | * the user to delete the wrong device. | |
1002 | */ | |
1003 | static ssize_t | |
1004 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
1005 | const char *buf, size_t count) | |
1006 | { | |
1007 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
1008 | struct i2c_client *client, *next; | |
1009 | unsigned short addr; | |
1010 | char end; | |
1011 | int res; | |
1012 | ||
1013 | /* Parse parameters, reject extra parameters */ | |
1014 | res = sscanf(buf, "%hi%c", &addr, &end); | |
1015 | if (res < 1) { | |
1016 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
1017 | return -EINVAL; | |
1018 | } | |
1019 | if (res > 1 && end != '\n') { | |
1020 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
1021 | return -EINVAL; | |
1022 | } | |
1023 | ||
1024 | /* Make sure the device was added through sysfs */ | |
1025 | res = -ENOENT; | |
390946b1 JD |
1026 | mutex_lock_nested(&adap->userspace_clients_lock, |
1027 | i2c_adapter_depth(adap)); | |
6629dcff JD |
1028 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1029 | detected) { | |
cfa0327b | 1030 | if (i2c_encode_flags_to_addr(client) == addr) { |
99cd8e25 JD |
1031 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
1032 | "delete_device", client->name, client->addr); | |
1033 | ||
1034 | list_del(&client->detected); | |
1035 | i2c_unregister_device(client); | |
1036 | res = count; | |
1037 | break; | |
1038 | } | |
1039 | } | |
dafc50d1 | 1040 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
1041 | |
1042 | if (res < 0) | |
1043 | dev_err(dev, "%s: Can't find device in list\n", | |
1044 | "delete_device"); | |
1045 | return res; | |
1046 | } | |
e9b526fe AS |
1047 | static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, |
1048 | i2c_sysfs_delete_device); | |
4f8cf824 JD |
1049 | |
1050 | static struct attribute *i2c_adapter_attrs[] = { | |
1051 | &dev_attr_name.attr, | |
1052 | &dev_attr_new_device.attr, | |
1053 | &dev_attr_delete_device.attr, | |
1054 | NULL | |
1055 | }; | |
a5eb71b2 | 1056 | ATTRIBUTE_GROUPS(i2c_adapter); |
b119dc3f | 1057 | |
0826374b | 1058 | struct device_type i2c_adapter_type = { |
a5eb71b2 | 1059 | .groups = i2c_adapter_groups, |
4f8cf824 | 1060 | .release = i2c_adapter_dev_release, |
1da177e4 | 1061 | }; |
0826374b | 1062 | EXPORT_SYMBOL_GPL(i2c_adapter_type); |
1da177e4 | 1063 | |
643dd09e SW |
1064 | /** |
1065 | * i2c_verify_adapter - return parameter as i2c_adapter or NULL | |
1066 | * @dev: device, probably from some driver model iterator | |
1067 | * | |
1068 | * When traversing the driver model tree, perhaps using driver model | |
1069 | * iterators like @device_for_each_child(), you can't assume very much | |
1070 | * about the nodes you find. Use this function to avoid oopses caused | |
1071 | * by wrongly treating some non-I2C device as an i2c_adapter. | |
1072 | */ | |
1073 | struct i2c_adapter *i2c_verify_adapter(struct device *dev) | |
1074 | { | |
1075 | return (dev->type == &i2c_adapter_type) | |
1076 | ? to_i2c_adapter(dev) | |
1077 | : NULL; | |
1078 | } | |
1079 | EXPORT_SYMBOL(i2c_verify_adapter); | |
1080 | ||
2bb5095a JD |
1081 | #ifdef CONFIG_I2C_COMPAT |
1082 | static struct class_compat *i2c_adapter_compat_class; | |
1083 | #endif | |
1084 | ||
9c1600ed DB |
1085 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
1086 | { | |
1087 | struct i2c_devinfo *devinfo; | |
1088 | ||
f18c41da | 1089 | down_read(&__i2c_board_lock); |
9c1600ed DB |
1090 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
1091 | if (devinfo->busnum == adapter->nr | |
1092 | && !i2c_new_device(adapter, | |
1093 | &devinfo->board_info)) | |
09b8ce0a ZX |
1094 | dev_err(&adapter->dev, |
1095 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
1096 | devinfo->board_info.addr); |
1097 | } | |
f18c41da | 1098 | up_read(&__i2c_board_lock); |
9c1600ed DB |
1099 | } |
1100 | ||
69b0089a JD |
1101 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
1102 | struct i2c_adapter *adap) | |
026526f5 | 1103 | { |
4735c98f JD |
1104 | /* Detect supported devices on that bus, and instantiate them */ |
1105 | i2c_detect(adap, driver); | |
1106 | ||
1107 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 | 1108 | if (driver->attach_adapter) { |
a920ff41 JD |
1109 | dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n", |
1110 | driver->driver.name); | |
b93d3d37 AS |
1111 | dev_warn(&adap->dev, |
1112 | "Please use another way to instantiate your i2c_client\n"); | |
026526f5 JD |
1113 | /* We ignore the return code; if it fails, too bad */ |
1114 | driver->attach_adapter(adap); | |
1115 | } | |
1116 | return 0; | |
1117 | } | |
1118 | ||
69b0089a JD |
1119 | static int __process_new_adapter(struct device_driver *d, void *data) |
1120 | { | |
1121 | return i2c_do_add_adapter(to_i2c_driver(d), data); | |
1122 | } | |
1123 | ||
d1ed7985 PR |
1124 | static const struct i2c_lock_operations i2c_adapter_lock_ops = { |
1125 | .lock_bus = i2c_adapter_lock_bus, | |
1126 | .trylock_bus = i2c_adapter_trylock_bus, | |
1127 | .unlock_bus = i2c_adapter_unlock_bus, | |
1128 | }; | |
1129 | ||
4d5538f5 BT |
1130 | static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap) |
1131 | { | |
1132 | struct irq_domain *domain = adap->host_notify_domain; | |
1133 | irq_hw_number_t hwirq; | |
1134 | ||
1135 | if (!domain) | |
1136 | return; | |
1137 | ||
1138 | for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++) | |
1139 | irq_dispose_mapping(irq_find_mapping(domain, hwirq)); | |
1140 | ||
1141 | irq_domain_remove(domain); | |
1142 | adap->host_notify_domain = NULL; | |
1143 | } | |
1144 | ||
1145 | static int i2c_host_notify_irq_map(struct irq_domain *h, | |
1146 | unsigned int virq, | |
1147 | irq_hw_number_t hw_irq_num) | |
1148 | { | |
1149 | irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); | |
1150 | ||
1151 | return 0; | |
1152 | } | |
1153 | ||
1154 | static const struct irq_domain_ops i2c_host_notify_irq_ops = { | |
1155 | .map = i2c_host_notify_irq_map, | |
1156 | }; | |
1157 | ||
1158 | static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap) | |
1159 | { | |
1160 | struct irq_domain *domain; | |
1161 | ||
1162 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY)) | |
1163 | return 0; | |
1164 | ||
1165 | domain = irq_domain_create_linear(adap->dev.fwnode, | |
1166 | I2C_ADDR_7BITS_COUNT, | |
1167 | &i2c_host_notify_irq_ops, adap); | |
1168 | if (!domain) | |
1169 | return -ENOMEM; | |
1170 | ||
1171 | adap->host_notify_domain = domain; | |
1172 | ||
1173 | return 0; | |
1174 | } | |
1175 | ||
1176 | /** | |
1177 | * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct | |
1178 | * I2C client. | |
1179 | * @adap: the adapter | |
1180 | * @addr: the I2C address of the notifying device | |
1181 | * Context: can't sleep | |
1182 | * | |
1183 | * Helper function to be called from an I2C bus driver's interrupt | |
1184 | * handler. It will schedule the Host Notify IRQ. | |
1185 | */ | |
1186 | int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr) | |
1187 | { | |
1188 | int irq; | |
1189 | ||
1190 | if (!adap) | |
1191 | return -EINVAL; | |
1192 | ||
1193 | irq = irq_find_mapping(adap->host_notify_domain, addr); | |
1194 | if (irq <= 0) | |
1195 | return -ENXIO; | |
1196 | ||
1197 | generic_handle_irq(irq); | |
1198 | ||
1199 | return 0; | |
1200 | } | |
1201 | EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify); | |
1202 | ||
6e13e641 | 1203 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 1204 | { |
ce0dffaf | 1205 | int res = -EINVAL; |
1da177e4 | 1206 | |
1d0b19c9 | 1207 | /* Can't register until after driver model init */ |
95026658 | 1208 | if (WARN_ON(!is_registered)) { |
35fc37f8 JD |
1209 | res = -EAGAIN; |
1210 | goto out_list; | |
1211 | } | |
1d0b19c9 | 1212 | |
2236baa7 | 1213 | /* Sanity checks */ |
8ddfe410 | 1214 | if (WARN(!adap->name[0], "i2c adapter has no name")) |
ce0dffaf | 1215 | goto out_list; |
8ddfe410 WS |
1216 | |
1217 | if (!adap->algo) { | |
44239a5a | 1218 | pr_err("adapter '%s': no algo supplied!\n", adap->name); |
ce0dffaf | 1219 | goto out_list; |
2236baa7 JD |
1220 | } |
1221 | ||
d1ed7985 PR |
1222 | if (!adap->lock_ops) |
1223 | adap->lock_ops = &i2c_adapter_lock_ops; | |
8320f495 | 1224 | |
194684e5 | 1225 | rt_mutex_init(&adap->bus_lock); |
6ef91fcc | 1226 | rt_mutex_init(&adap->mux_lock); |
dafc50d1 | 1227 | mutex_init(&adap->userspace_clients_lock); |
6629dcff | 1228 | INIT_LIST_HEAD(&adap->userspace_clients); |
1da177e4 | 1229 | |
8fcfef6e JD |
1230 | /* Set default timeout to 1 second if not already set */ |
1231 | if (adap->timeout == 0) | |
1232 | adap->timeout = HZ; | |
1233 | ||
4d5538f5 BT |
1234 | /* register soft irqs for Host Notify */ |
1235 | res = i2c_setup_host_notify_irq_domain(adap); | |
1236 | if (res) { | |
1237 | pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n", | |
1238 | adap->name, res); | |
1239 | goto out_list; | |
1240 | } | |
1241 | ||
27d9c183 | 1242 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
1243 | adap->dev.bus = &i2c_bus_type; |
1244 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 | 1245 | res = device_register(&adap->dev); |
8ddfe410 | 1246 | if (res) { |
44239a5a | 1247 | pr_err("adapter '%s': can't register device (%d)\n", adap->name, res); |
b119c6c9 | 1248 | goto out_list; |
8ddfe410 | 1249 | } |
1da177e4 | 1250 | |
f8756c67 PR |
1251 | res = of_i2c_setup_smbus_alert(adap); |
1252 | if (res) | |
1253 | goto out_reg; | |
1254 | ||
b6d7b3d1 JD |
1255 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
1256 | ||
6ada5c1e | 1257 | pm_runtime_no_callbacks(&adap->dev); |
04f59143 | 1258 | pm_suspend_ignore_children(&adap->dev, true); |
9f924169 | 1259 | pm_runtime_enable(&adap->dev); |
6ada5c1e | 1260 | |
2bb5095a JD |
1261 | #ifdef CONFIG_I2C_COMPAT |
1262 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
1263 | adap->dev.parent); | |
1264 | if (res) | |
1265 | dev_warn(&adap->dev, | |
1266 | "Failed to create compatibility class link\n"); | |
1267 | #endif | |
1268 | ||
d3b11d83 | 1269 | i2c_init_recovery(adap); |
5f9296ba | 1270 | |
729d6dd5 | 1271 | /* create pre-declared device nodes */ |
687b81d0 | 1272 | of_i2c_register_devices(adap); |
aec809fc JN |
1273 | i2c_acpi_register_devices(adap); |
1274 | i2c_acpi_install_space_handler(adap); | |
687b81d0 | 1275 | |
6e13e641 DB |
1276 | if (adap->nr < __i2c_first_dynamic_bus_num) |
1277 | i2c_scan_static_board_info(adap); | |
1278 | ||
4735c98f | 1279 | /* Notify drivers */ |
35fc37f8 | 1280 | mutex_lock(&core_lock); |
d6703281 | 1281 | bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); |
caada32a | 1282 | mutex_unlock(&core_lock); |
35fc37f8 JD |
1283 | |
1284 | return 0; | |
b119c6c9 | 1285 | |
f8756c67 PR |
1286 | out_reg: |
1287 | init_completion(&adap->dev_released); | |
1288 | device_unregister(&adap->dev); | |
1289 | wait_for_completion(&adap->dev_released); | |
b119c6c9 | 1290 | out_list: |
35fc37f8 | 1291 | mutex_lock(&core_lock); |
b119c6c9 | 1292 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
1293 | mutex_unlock(&core_lock); |
1294 | return res; | |
1da177e4 LT |
1295 | } |
1296 | ||
ee5c2744 DA |
1297 | /** |
1298 | * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 | |
1299 | * @adap: the adapter to register (with adap->nr initialized) | |
1300 | * Context: can sleep | |
1301 | * | |
1302 | * See i2c_add_numbered_adapter() for details. | |
1303 | */ | |
1304 | static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1305 | { | |
84d0b617 | 1306 | int id; |
ee5c2744 DA |
1307 | |
1308 | mutex_lock(&core_lock); | |
84d0b617 | 1309 | id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL); |
ee5c2744 | 1310 | mutex_unlock(&core_lock); |
84d0b617 | 1311 | if (WARN(id < 0, "couldn't get idr")) |
ee5c2744 DA |
1312 | return id == -ENOSPC ? -EBUSY : id; |
1313 | ||
1314 | return i2c_register_adapter(adap); | |
1315 | } | |
1316 | ||
6e13e641 DB |
1317 | /** |
1318 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
1319 | * @adapter: the adapter to add | |
d64f73be | 1320 | * Context: can sleep |
6e13e641 DB |
1321 | * |
1322 | * This routine is used to declare an I2C adapter when its bus number | |
ee5c2744 DA |
1323 | * doesn't matter or when its bus number is specified by an dt alias. |
1324 | * Examples of bases when the bus number doesn't matter: I2C adapters | |
1325 | * dynamically added by USB links or PCI plugin cards. | |
6e13e641 DB |
1326 | * |
1327 | * When this returns zero, a new bus number was allocated and stored | |
1328 | * in adap->nr, and the specified adapter became available for clients. | |
1329 | * Otherwise, a negative errno value is returned. | |
1330 | */ | |
1331 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
1332 | { | |
ee5c2744 | 1333 | struct device *dev = &adapter->dev; |
4ae42b0f | 1334 | int id; |
6e13e641 | 1335 | |
ee5c2744 DA |
1336 | if (dev->of_node) { |
1337 | id = of_alias_get_id(dev->of_node, "i2c"); | |
1338 | if (id >= 0) { | |
1339 | adapter->nr = id; | |
1340 | return __i2c_add_numbered_adapter(adapter); | |
1341 | } | |
1342 | } | |
1343 | ||
caada32a | 1344 | mutex_lock(&core_lock); |
4ae42b0f TH |
1345 | id = idr_alloc(&i2c_adapter_idr, adapter, |
1346 | __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); | |
caada32a | 1347 | mutex_unlock(&core_lock); |
84d0b617 | 1348 | if (WARN(id < 0, "couldn't get idr")) |
4ae42b0f | 1349 | return id; |
6e13e641 DB |
1350 | |
1351 | adapter->nr = id; | |
4ae42b0f | 1352 | |
6e13e641 DB |
1353 | return i2c_register_adapter(adapter); |
1354 | } | |
1355 | EXPORT_SYMBOL(i2c_add_adapter); | |
1356 | ||
1357 | /** | |
1358 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
1359 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 1360 | * Context: can sleep |
6e13e641 DB |
1361 | * |
1362 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
1363 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
1364 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
1365 | * is used to properly configure I2C devices. |
1366 | * | |
488bf314 GL |
1367 | * If the requested bus number is set to -1, then this function will behave |
1368 | * identically to i2c_add_adapter, and will dynamically assign a bus number. | |
1369 | * | |
6e13e641 DB |
1370 | * If no devices have pre-been declared for this bus, then be sure to |
1371 | * register the adapter before any dynamically allocated ones. Otherwise | |
1372 | * the required bus ID may not be available. | |
1373 | * | |
1374 | * When this returns zero, the specified adapter became available for | |
1375 | * clients using the bus number provided in adap->nr. Also, the table | |
1376 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
1377 | * and the appropriate driver model device nodes are created. Otherwise, a | |
1378 | * negative errno value is returned. | |
1379 | */ | |
1380 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1381 | { | |
488bf314 GL |
1382 | if (adap->nr == -1) /* -1 means dynamically assign bus id */ |
1383 | return i2c_add_adapter(adap); | |
6e13e641 | 1384 | |
ee5c2744 | 1385 | return __i2c_add_numbered_adapter(adap); |
6e13e641 DB |
1386 | } |
1387 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
1388 | ||
19baba4c | 1389 | static void i2c_do_del_adapter(struct i2c_driver *driver, |
69b0089a | 1390 | struct i2c_adapter *adapter) |
026526f5 | 1391 | { |
4735c98f | 1392 | struct i2c_client *client, *_n; |
026526f5 | 1393 | |
acec211c JD |
1394 | /* Remove the devices we created ourselves as the result of hardware |
1395 | * probing (using a driver's detect method) */ | |
4735c98f JD |
1396 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
1397 | if (client->adapter == adapter) { | |
1398 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
1399 | client->name, client->addr); | |
1400 | list_del(&client->detected); | |
1401 | i2c_unregister_device(client); | |
1402 | } | |
1403 | } | |
026526f5 JD |
1404 | } |
1405 | ||
e549c2b5 | 1406 | static int __unregister_client(struct device *dev, void *dummy) |
5219bf88 JD |
1407 | { |
1408 | struct i2c_client *client = i2c_verify_client(dev); | |
1409 | if (client && strcmp(client->name, "dummy")) | |
1410 | i2c_unregister_device(client); | |
1411 | return 0; | |
1412 | } | |
1413 | ||
1414 | static int __unregister_dummy(struct device *dev, void *dummy) | |
e549c2b5 JD |
1415 | { |
1416 | struct i2c_client *client = i2c_verify_client(dev); | |
7b43dd19 | 1417 | i2c_unregister_device(client); |
e549c2b5 JD |
1418 | return 0; |
1419 | } | |
1420 | ||
69b0089a JD |
1421 | static int __process_removed_adapter(struct device_driver *d, void *data) |
1422 | { | |
19baba4c LPC |
1423 | i2c_do_del_adapter(to_i2c_driver(d), data); |
1424 | return 0; | |
69b0089a JD |
1425 | } |
1426 | ||
d64f73be DB |
1427 | /** |
1428 | * i2c_del_adapter - unregister I2C adapter | |
1429 | * @adap: the adapter being unregistered | |
1430 | * Context: can sleep | |
1431 | * | |
1432 | * This unregisters an I2C adapter which was previously registered | |
1433 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
1434 | */ | |
71546300 | 1435 | void i2c_del_adapter(struct i2c_adapter *adap) |
1da177e4 | 1436 | { |
35fc37f8 | 1437 | struct i2c_adapter *found; |
bbd2d9c9 | 1438 | struct i2c_client *client, *next; |
1da177e4 LT |
1439 | |
1440 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
1441 | mutex_lock(&core_lock); |
1442 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
1443 | mutex_unlock(&core_lock); | |
1444 | if (found != adap) { | |
44239a5a | 1445 | pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name); |
71546300 | 1446 | return; |
1da177e4 LT |
1447 | } |
1448 | ||
aec809fc | 1449 | i2c_acpi_remove_space_handler(adap); |
026526f5 | 1450 | /* Tell drivers about this removal */ |
35fc37f8 | 1451 | mutex_lock(&core_lock); |
19baba4c | 1452 | bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 1453 | __process_removed_adapter); |
35fc37f8 | 1454 | mutex_unlock(&core_lock); |
1da177e4 | 1455 | |
bbd2d9c9 | 1456 | /* Remove devices instantiated from sysfs */ |
390946b1 JD |
1457 | mutex_lock_nested(&adap->userspace_clients_lock, |
1458 | i2c_adapter_depth(adap)); | |
6629dcff JD |
1459 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1460 | detected) { | |
1461 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, | |
1462 | client->addr); | |
1463 | list_del(&client->detected); | |
1464 | i2c_unregister_device(client); | |
bbd2d9c9 | 1465 | } |
dafc50d1 | 1466 | mutex_unlock(&adap->userspace_clients_lock); |
bbd2d9c9 | 1467 | |
e549c2b5 | 1468 | /* Detach any active clients. This can't fail, thus we do not |
5219bf88 JD |
1469 | * check the returned value. This is a two-pass process, because |
1470 | * we can't remove the dummy devices during the first pass: they | |
1471 | * could have been instantiated by real devices wishing to clean | |
1472 | * them up properly, so we give them a chance to do that first. */ | |
19baba4c LPC |
1473 | device_for_each_child(&adap->dev, NULL, __unregister_client); |
1474 | device_for_each_child(&adap->dev, NULL, __unregister_dummy); | |
1da177e4 | 1475 | |
2bb5095a JD |
1476 | #ifdef CONFIG_I2C_COMPAT |
1477 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
1478 | adap->dev.parent); | |
1479 | #endif | |
1480 | ||
c5567521 TLSC |
1481 | /* device name is gone after device_unregister */ |
1482 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); | |
1483 | ||
9f924169 WS |
1484 | pm_runtime_disable(&adap->dev); |
1485 | ||
4d5538f5 BT |
1486 | i2c_host_notify_irq_teardown(adap); |
1487 | ||
26680ee2 WS |
1488 | /* wait until all references to the device are gone |
1489 | * | |
1490 | * FIXME: This is old code and should ideally be replaced by an | |
1491 | * alternative which results in decoupling the lifetime of the struct | |
1492 | * device from the i2c_adapter, like spi or netdev do. Any solution | |
95cc1e3d | 1493 | * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled! |
26680ee2 | 1494 | */ |
1da177e4 | 1495 | init_completion(&adap->dev_released); |
1da177e4 | 1496 | device_unregister(&adap->dev); |
1da177e4 | 1497 | wait_for_completion(&adap->dev_released); |
1da177e4 | 1498 | |
6e13e641 | 1499 | /* free bus id */ |
35fc37f8 | 1500 | mutex_lock(&core_lock); |
1da177e4 | 1501 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 1502 | mutex_unlock(&core_lock); |
1da177e4 | 1503 | |
bd4bc3db JD |
1504 | /* Clear the device structure in case this adapter is ever going to be |
1505 | added again */ | |
1506 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
1da177e4 | 1507 | } |
c0564606 | 1508 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 | 1509 | |
54177ccf WS |
1510 | /** |
1511 | * i2c_parse_fw_timings - get I2C related timing parameters from firmware | |
1512 | * @dev: The device to scan for I2C timing properties | |
1513 | * @t: the i2c_timings struct to be filled with values | |
1514 | * @use_defaults: bool to use sane defaults derived from the I2C specification | |
1515 | * when properties are not found, otherwise use 0 | |
1516 | * | |
1517 | * Scan the device for the generic I2C properties describing timing parameters | |
1518 | * for the signal and fill the given struct with the results. If a property was | |
1519 | * not found and use_defaults was true, then maximum timings are assumed which | |
1520 | * are derived from the I2C specification. If use_defaults is not used, the | |
1521 | * results will be 0, so drivers can apply their own defaults later. The latter | |
1522 | * is mainly intended for avoiding regressions of existing drivers which want | |
1523 | * to switch to this function. New drivers almost always should use the defaults. | |
1524 | */ | |
1525 | ||
1526 | void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults) | |
1527 | { | |
1528 | int ret; | |
1529 | ||
1530 | memset(t, 0, sizeof(*t)); | |
1531 | ||
1532 | ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz); | |
1533 | if (ret && use_defaults) | |
1534 | t->bus_freq_hz = 100000; | |
1535 | ||
1536 | ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns); | |
1537 | if (ret && use_defaults) { | |
1538 | if (t->bus_freq_hz <= 100000) | |
1539 | t->scl_rise_ns = 1000; | |
1540 | else if (t->bus_freq_hz <= 400000) | |
1541 | t->scl_rise_ns = 300; | |
1542 | else | |
1543 | t->scl_rise_ns = 120; | |
1544 | } | |
1545 | ||
1546 | ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns); | |
1547 | if (ret && use_defaults) { | |
1548 | if (t->bus_freq_hz <= 400000) | |
1549 | t->scl_fall_ns = 300; | |
1550 | else | |
1551 | t->scl_fall_ns = 120; | |
1552 | } | |
1553 | ||
1554 | device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns); | |
1555 | ||
1556 | ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns); | |
1557 | if (ret && use_defaults) | |
1558 | t->sda_fall_ns = t->scl_fall_ns; | |
1559 | } | |
1560 | EXPORT_SYMBOL_GPL(i2c_parse_fw_timings); | |
1561 | ||
7b4fbc50 DB |
1562 | /* ------------------------------------------------------------------------- */ |
1563 | ||
7ae31482 JD |
1564 | int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) |
1565 | { | |
1566 | int res; | |
1567 | ||
1568 | mutex_lock(&core_lock); | |
1569 | res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); | |
1570 | mutex_unlock(&core_lock); | |
1571 | ||
1572 | return res; | |
1573 | } | |
1574 | EXPORT_SYMBOL_GPL(i2c_for_each_dev); | |
1575 | ||
69b0089a | 1576 | static int __process_new_driver(struct device *dev, void *data) |
7f101a97 | 1577 | { |
4f8cf824 JD |
1578 | if (dev->type != &i2c_adapter_type) |
1579 | return 0; | |
69b0089a | 1580 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
7f101a97 DY |
1581 | } |
1582 | ||
7b4fbc50 DB |
1583 | /* |
1584 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 1585 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
1586 | */ |
1587 | ||
de59cf9e | 1588 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 1589 | { |
7eebcb7c | 1590 | int res; |
1da177e4 | 1591 | |
1d0b19c9 | 1592 | /* Can't register until after driver model init */ |
95026658 | 1593 | if (WARN_ON(!is_registered)) |
1d0b19c9 DB |
1594 | return -EAGAIN; |
1595 | ||
1da177e4 | 1596 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 1597 | driver->driver.owner = owner; |
1da177e4 | 1598 | driver->driver.bus = &i2c_bus_type; |
147b36d5 | 1599 | INIT_LIST_HEAD(&driver->clients); |
1da177e4 | 1600 | |
729d6dd5 | 1601 | /* When registration returns, the driver core |
6e13e641 DB |
1602 | * will have called probe() for all matching-but-unbound devices. |
1603 | */ | |
1da177e4 LT |
1604 | res = driver_register(&driver->driver); |
1605 | if (res) | |
7eebcb7c | 1606 | return res; |
438d6c2c | 1607 | |
44239a5a | 1608 | pr_debug("driver [%s] registered\n", driver->driver.name); |
1da177e4 | 1609 | |
4735c98f | 1610 | /* Walk the adapters that are already present */ |
7ae31482 | 1611 | i2c_for_each_dev(driver, __process_new_driver); |
35fc37f8 | 1612 | |
7f101a97 DY |
1613 | return 0; |
1614 | } | |
1615 | EXPORT_SYMBOL(i2c_register_driver); | |
1616 | ||
69b0089a | 1617 | static int __process_removed_driver(struct device *dev, void *data) |
7f101a97 | 1618 | { |
19baba4c LPC |
1619 | if (dev->type == &i2c_adapter_type) |
1620 | i2c_do_del_adapter(data, to_i2c_adapter(dev)); | |
1621 | return 0; | |
1da177e4 LT |
1622 | } |
1623 | ||
a1d9e6e4 DB |
1624 | /** |
1625 | * i2c_del_driver - unregister I2C driver | |
1626 | * @driver: the driver being unregistered | |
d64f73be | 1627 | * Context: can sleep |
a1d9e6e4 | 1628 | */ |
b3e82096 | 1629 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 1630 | { |
7ae31482 | 1631 | i2c_for_each_dev(driver, __process_removed_driver); |
1da177e4 LT |
1632 | |
1633 | driver_unregister(&driver->driver); | |
44239a5a | 1634 | pr_debug("driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 1635 | } |
c0564606 | 1636 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 1637 | |
7b4fbc50 DB |
1638 | /* ------------------------------------------------------------------------- */ |
1639 | ||
e48d3319 JD |
1640 | /** |
1641 | * i2c_use_client - increments the reference count of the i2c client structure | |
1642 | * @client: the client being referenced | |
1643 | * | |
1644 | * Each live reference to a client should be refcounted. The driver model does | |
1645 | * that automatically as part of driver binding, so that most drivers don't | |
1646 | * need to do this explicitly: they hold a reference until they're unbound | |
1647 | * from the device. | |
1648 | * | |
1649 | * A pointer to the client with the incremented reference counter is returned. | |
1650 | */ | |
1651 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 1652 | { |
6ea438ec DB |
1653 | if (client && get_device(&client->dev)) |
1654 | return client; | |
1655 | return NULL; | |
1da177e4 | 1656 | } |
c0564606 | 1657 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 1658 | |
e48d3319 JD |
1659 | /** |
1660 | * i2c_release_client - release a use of the i2c client structure | |
1661 | * @client: the client being no longer referenced | |
1662 | * | |
1663 | * Must be called when a user of a client is finished with it. | |
1664 | */ | |
1665 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 1666 | { |
6ea438ec DB |
1667 | if (client) |
1668 | put_device(&client->dev); | |
1da177e4 | 1669 | } |
c0564606 | 1670 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 1671 | |
9b766b81 DB |
1672 | struct i2c_cmd_arg { |
1673 | unsigned cmd; | |
1674 | void *arg; | |
1675 | }; | |
1676 | ||
1677 | static int i2c_cmd(struct device *dev, void *_arg) | |
1678 | { | |
1679 | struct i2c_client *client = i2c_verify_client(dev); | |
1680 | struct i2c_cmd_arg *arg = _arg; | |
0acc2b32 LPC |
1681 | struct i2c_driver *driver; |
1682 | ||
1683 | if (!client || !client->dev.driver) | |
1684 | return 0; | |
9b766b81 | 1685 | |
0acc2b32 LPC |
1686 | driver = to_i2c_driver(client->dev.driver); |
1687 | if (driver->command) | |
1688 | driver->command(client, arg->cmd, arg->arg); | |
9b766b81 DB |
1689 | return 0; |
1690 | } | |
1691 | ||
1da177e4 LT |
1692 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
1693 | { | |
9b766b81 | 1694 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 1695 | |
9b766b81 DB |
1696 | cmd_arg.cmd = cmd; |
1697 | cmd_arg.arg = arg; | |
1698 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 1699 | } |
c0564606 | 1700 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
1701 | |
1702 | static int __init i2c_init(void) | |
1703 | { | |
1704 | int retval; | |
1705 | ||
03bde7c3 WS |
1706 | retval = of_alias_get_highest_id("i2c"); |
1707 | ||
1708 | down_write(&__i2c_board_lock); | |
1709 | if (retval >= __i2c_first_dynamic_bus_num) | |
1710 | __i2c_first_dynamic_bus_num = retval + 1; | |
1711 | up_write(&__i2c_board_lock); | |
1712 | ||
1da177e4 | 1713 | retval = bus_register(&i2c_bus_type); |
1da177e4 LT |
1714 | if (retval) |
1715 | return retval; | |
b980a26d WS |
1716 | |
1717 | is_registered = true; | |
1718 | ||
2bb5095a JD |
1719 | #ifdef CONFIG_I2C_COMPAT |
1720 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
1721 | if (!i2c_adapter_compat_class) { | |
1722 | retval = -ENOMEM; | |
1723 | goto bus_err; | |
1724 | } | |
1725 | #endif | |
e9f1373b DB |
1726 | retval = i2c_add_driver(&dummy_driver); |
1727 | if (retval) | |
2bb5095a | 1728 | goto class_err; |
ea7513bb PA |
1729 | |
1730 | if (IS_ENABLED(CONFIG_OF_DYNAMIC)) | |
1731 | WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)); | |
525e6fab OP |
1732 | if (IS_ENABLED(CONFIG_ACPI)) |
1733 | WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier)); | |
ea7513bb | 1734 | |
e9f1373b DB |
1735 | return 0; |
1736 | ||
2bb5095a JD |
1737 | class_err: |
1738 | #ifdef CONFIG_I2C_COMPAT | |
1739 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 1740 | bus_err: |
2bb5095a | 1741 | #endif |
b980a26d | 1742 | is_registered = false; |
e9f1373b DB |
1743 | bus_unregister(&i2c_bus_type); |
1744 | return retval; | |
1da177e4 LT |
1745 | } |
1746 | ||
1747 | static void __exit i2c_exit(void) | |
1748 | { | |
525e6fab OP |
1749 | if (IS_ENABLED(CONFIG_ACPI)) |
1750 | WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier)); | |
ea7513bb PA |
1751 | if (IS_ENABLED(CONFIG_OF_DYNAMIC)) |
1752 | WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier)); | |
e9f1373b | 1753 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
1754 | #ifdef CONFIG_I2C_COMPAT |
1755 | class_compat_unregister(i2c_adapter_compat_class); | |
1756 | #endif | |
1da177e4 | 1757 | bus_unregister(&i2c_bus_type); |
d9a83d62 | 1758 | tracepoint_synchronize_unregister(); |
1da177e4 LT |
1759 | } |
1760 | ||
a10f9e7c DB |
1761 | /* We must initialize early, because some subsystems register i2c drivers |
1762 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1763 | */ | |
1764 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1765 | module_exit(i2c_exit); |
1766 | ||
1767 | /* ---------------------------------------------------- | |
1768 | * the functional interface to the i2c busses. | |
1769 | * ---------------------------------------------------- | |
1770 | */ | |
1771 | ||
b7f62584 WS |
1772 | /* Check if val is exceeding the quirk IFF quirk is non 0 */ |
1773 | #define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk))) | |
1774 | ||
1775 | static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg) | |
1776 | { | |
1777 | dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n", | |
1778 | err_msg, msg->addr, msg->len, | |
1779 | msg->flags & I2C_M_RD ? "read" : "write"); | |
1780 | return -EOPNOTSUPP; | |
1781 | } | |
1782 | ||
1783 | static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
1784 | { | |
1785 | const struct i2c_adapter_quirks *q = adap->quirks; | |
1786 | int max_num = q->max_num_msgs, i; | |
1787 | bool do_len_check = true; | |
1788 | ||
1789 | if (q->flags & I2C_AQ_COMB) { | |
1790 | max_num = 2; | |
1791 | ||
1792 | /* special checks for combined messages */ | |
1793 | if (num == 2) { | |
1794 | if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD) | |
1795 | return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write"); | |
1796 | ||
1797 | if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD)) | |
1798 | return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read"); | |
1799 | ||
1800 | if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr) | |
1801 | return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr"); | |
1802 | ||
1803 | if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len)) | |
1804 | return i2c_quirk_error(adap, &msgs[0], "msg too long"); | |
1805 | ||
1806 | if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len)) | |
1807 | return i2c_quirk_error(adap, &msgs[1], "msg too long"); | |
1808 | ||
1809 | do_len_check = false; | |
1810 | } | |
1811 | } | |
1812 | ||
1813 | if (i2c_quirk_exceeded(num, max_num)) | |
1814 | return i2c_quirk_error(adap, &msgs[0], "too many messages"); | |
1815 | ||
1816 | for (i = 0; i < num; i++) { | |
1817 | u16 len = msgs[i].len; | |
1818 | ||
1819 | if (msgs[i].flags & I2C_M_RD) { | |
1820 | if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len)) | |
1821 | return i2c_quirk_error(adap, &msgs[i], "msg too long"); | |
1822 | } else { | |
1823 | if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len)) | |
1824 | return i2c_quirk_error(adap, &msgs[i], "msg too long"); | |
1825 | } | |
1826 | } | |
1827 | ||
1828 | return 0; | |
1829 | } | |
1830 | ||
b37d2a3a JD |
1831 | /** |
1832 | * __i2c_transfer - unlocked flavor of i2c_transfer | |
1833 | * @adap: Handle to I2C bus | |
1834 | * @msgs: One or more messages to execute before STOP is issued to | |
1835 | * terminate the operation; each message begins with a START. | |
1836 | * @num: Number of messages to be executed. | |
1837 | * | |
1838 | * Returns negative errno, else the number of messages executed. | |
1839 | * | |
1840 | * Adapter lock must be held when calling this function. No debug logging | |
1841 | * takes place. adap->algo->master_xfer existence isn't checked. | |
1842 | */ | |
1843 | int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
1844 | { | |
1845 | unsigned long orig_jiffies; | |
1846 | int ret, try; | |
1847 | ||
1eace834 AB |
1848 | if (WARN_ON(!msgs || num < 1)) |
1849 | return -EINVAL; | |
1850 | ||
b7f62584 WS |
1851 | if (adap->quirks && i2c_check_for_quirks(adap, msgs, num)) |
1852 | return -EOPNOTSUPP; | |
1853 | ||
50888b01 DB |
1854 | /* |
1855 | * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets | |
d9a83d62 DH |
1856 | * enabled. This is an efficient way of keeping the for-loop from |
1857 | * being executed when not needed. | |
1858 | */ | |
50888b01 | 1859 | if (static_branch_unlikely(&i2c_trace_msg_key)) { |
d9a83d62 DH |
1860 | int i; |
1861 | for (i = 0; i < num; i++) | |
1862 | if (msgs[i].flags & I2C_M_RD) | |
1863 | trace_i2c_read(adap, &msgs[i], i); | |
1864 | else | |
1865 | trace_i2c_write(adap, &msgs[i], i); | |
1866 | } | |
1867 | ||
b37d2a3a JD |
1868 | /* Retry automatically on arbitration loss */ |
1869 | orig_jiffies = jiffies; | |
1870 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
1871 | ret = adap->algo->master_xfer(adap, msgs, num); | |
1872 | if (ret != -EAGAIN) | |
1873 | break; | |
1874 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
1875 | break; | |
1876 | } | |
1877 | ||
50888b01 | 1878 | if (static_branch_unlikely(&i2c_trace_msg_key)) { |
d9a83d62 DH |
1879 | int i; |
1880 | for (i = 0; i < ret; i++) | |
1881 | if (msgs[i].flags & I2C_M_RD) | |
1882 | trace_i2c_reply(adap, &msgs[i], i); | |
4a3f7691 | 1883 | trace_i2c_result(adap, num, ret); |
d9a83d62 DH |
1884 | } |
1885 | ||
b37d2a3a JD |
1886 | return ret; |
1887 | } | |
1888 | EXPORT_SYMBOL(__i2c_transfer); | |
1889 | ||
a1cdedac DB |
1890 | /** |
1891 | * i2c_transfer - execute a single or combined I2C message | |
1892 | * @adap: Handle to I2C bus | |
1893 | * @msgs: One or more messages to execute before STOP is issued to | |
1894 | * terminate the operation; each message begins with a START. | |
1895 | * @num: Number of messages to be executed. | |
1896 | * | |
1897 | * Returns negative errno, else the number of messages executed. | |
1898 | * | |
1899 | * Note that there is no requirement that each message be sent to | |
1900 | * the same slave address, although that is the most common model. | |
1901 | */ | |
09b8ce0a | 1902 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 1903 | { |
b37d2a3a | 1904 | int ret; |
1da177e4 | 1905 | |
a1cdedac DB |
1906 | /* REVISIT the fault reporting model here is weak: |
1907 | * | |
1908 | * - When we get an error after receiving N bytes from a slave, | |
1909 | * there is no way to report "N". | |
1910 | * | |
1911 | * - When we get a NAK after transmitting N bytes to a slave, | |
1912 | * there is no way to report "N" ... or to let the master | |
1913 | * continue executing the rest of this combined message, if | |
1914 | * that's the appropriate response. | |
1915 | * | |
1916 | * - When for example "num" is two and we successfully complete | |
1917 | * the first message but get an error part way through the | |
1918 | * second, it's unclear whether that should be reported as | |
1919 | * one (discarding status on the second message) or errno | |
1920 | * (discarding status on the first one). | |
1921 | */ | |
1922 | ||
1da177e4 LT |
1923 | if (adap->algo->master_xfer) { |
1924 | #ifdef DEBUG | |
1925 | for (ret = 0; ret < num; ret++) { | |
b93d3d37 AS |
1926 | dev_dbg(&adap->dev, |
1927 | "master_xfer[%d] %c, addr=0x%02x, len=%d%s\n", | |
1928 | ret, (msgs[ret].flags & I2C_M_RD) ? 'R' : 'W', | |
1929 | msgs[ret].addr, msgs[ret].len, | |
209d27c3 | 1930 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); |
1da177e4 LT |
1931 | } |
1932 | #endif | |
1933 | ||
cea443a8 | 1934 | if (in_atomic() || irqs_disabled()) { |
fb79e09a | 1935 | ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT); |
cea443a8 MR |
1936 | if (!ret) |
1937 | /* I2C activity is ongoing. */ | |
1938 | return -EAGAIN; | |
1939 | } else { | |
8320f495 | 1940 | i2c_lock_bus(adap, I2C_LOCK_SEGMENT); |
cea443a8 MR |
1941 | } |
1942 | ||
b37d2a3a | 1943 | ret = __i2c_transfer(adap, msgs, num); |
8320f495 | 1944 | i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); |
1da177e4 LT |
1945 | |
1946 | return ret; | |
1947 | } else { | |
1948 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1949 | return -EOPNOTSUPP; |
1da177e4 LT |
1950 | } |
1951 | } | |
c0564606 | 1952 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1953 | |
a1cdedac | 1954 | /** |
8a91732b WS |
1955 | * i2c_transfer_buffer_flags - issue a single I2C message transferring data |
1956 | * to/from a buffer | |
a1cdedac | 1957 | * @client: Handle to slave device |
8a91732b WS |
1958 | * @buf: Where the data is stored |
1959 | * @count: How many bytes to transfer, must be less than 64k since msg.len is u16 | |
1960 | * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads | |
a1cdedac | 1961 | * |
8a91732b | 1962 | * Returns negative errno, or else the number of bytes transferred. |
a1cdedac | 1963 | */ |
8a91732b WS |
1964 | int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, |
1965 | int count, u16 flags) | |
1da177e4 | 1966 | { |
1da177e4 | 1967 | int ret; |
8a91732b WS |
1968 | struct i2c_msg msg = { |
1969 | .addr = client->addr, | |
1970 | .flags = flags | (client->flags & I2C_M_TEN), | |
1971 | .len = count, | |
1972 | .buf = buf, | |
1973 | }; | |
815f55f2 | 1974 | |
8a91732b | 1975 | ret = i2c_transfer(client->adapter, &msg, 1); |
815f55f2 | 1976 | |
834aa6f3 | 1977 | /* |
8a91732b WS |
1978 | * If everything went ok (i.e. 1 msg transferred), return #bytes |
1979 | * transferred, else error code. | |
834aa6f3 | 1980 | */ |
815f55f2 | 1981 | return (ret == 1) ? count : ret; |
1da177e4 | 1982 | } |
8a91732b | 1983 | EXPORT_SYMBOL(i2c_transfer_buffer_flags); |
1da177e4 | 1984 | |
dde67eb1 PR |
1985 | /** |
1986 | * i2c_get_device_id - get manufacturer, part id and die revision of a device | |
1987 | * @client: The device to query | |
1988 | * @id: The queried information | |
1989 | * | |
1990 | * Returns negative errno on error, zero on success. | |
1991 | */ | |
1992 | int i2c_get_device_id(const struct i2c_client *client, | |
1993 | struct i2c_device_identity *id) | |
1994 | { | |
1995 | struct i2c_adapter *adap = client->adapter; | |
1996 | union i2c_smbus_data raw_id; | |
1997 | int ret; | |
1998 | ||
1999 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) | |
2000 | return -EOPNOTSUPP; | |
2001 | ||
2002 | raw_id.block[0] = 3; | |
2003 | ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0, | |
2004 | I2C_SMBUS_READ, client->addr << 1, | |
2005 | I2C_SMBUS_I2C_BLOCK_DATA, &raw_id); | |
2006 | if (ret) | |
2007 | return ret; | |
2008 | ||
2009 | id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4); | |
2010 | id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3); | |
2011 | id->die_revision = raw_id.block[3] & 0x7; | |
2012 | return 0; | |
2013 | } | |
2014 | EXPORT_SYMBOL_GPL(i2c_get_device_id); | |
2015 | ||
1da177e4 LT |
2016 | /* ---------------------------------------------------- |
2017 | * the i2c address scanning function | |
2018 | * Will not work for 10-bit addresses! | |
2019 | * ---------------------------------------------------- | |
2020 | */ | |
1da177e4 | 2021 | |
63e4e802 JD |
2022 | /* |
2023 | * Legacy default probe function, mostly relevant for SMBus. The default | |
2024 | * probe method is a quick write, but it is known to corrupt the 24RF08 | |
2025 | * EEPROMs due to a state machine bug, and could also irreversibly | |
2026 | * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, | |
2027 | * we use a short byte read instead. Also, some bus drivers don't implement | |
2028 | * quick write, so we fallback to a byte read in that case too. | |
2029 | * On x86, there is another special case for FSC hardware monitoring chips, | |
2030 | * which want regular byte reads (address 0x73.) Fortunately, these are the | |
2031 | * only known chips using this I2C address on PC hardware. | |
2032 | * Returns 1 if probe succeeded, 0 if not. | |
2033 | */ | |
2034 | static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) | |
2035 | { | |
2036 | int err; | |
2037 | union i2c_smbus_data dummy; | |
2038 | ||
2039 | #ifdef CONFIG_X86 | |
2040 | if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) | |
2041 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) | |
2042 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
2043 | I2C_SMBUS_BYTE_DATA, &dummy); | |
2044 | else | |
2045 | #endif | |
8031d79b JD |
2046 | if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) |
2047 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) | |
63e4e802 JD |
2048 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, |
2049 | I2C_SMBUS_QUICK, NULL); | |
8031d79b JD |
2050 | else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) |
2051 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
2052 | I2C_SMBUS_BYTE, &dummy); | |
2053 | else { | |
d63a9e85 AL |
2054 | dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", |
2055 | addr); | |
8031d79b JD |
2056 | err = -EOPNOTSUPP; |
2057 | } | |
63e4e802 JD |
2058 | |
2059 | return err >= 0; | |
2060 | } | |
2061 | ||
ccfbbd08 | 2062 | static int i2c_detect_address(struct i2c_client *temp_client, |
4735c98f JD |
2063 | struct i2c_driver *driver) |
2064 | { | |
2065 | struct i2c_board_info info; | |
2066 | struct i2c_adapter *adapter = temp_client->adapter; | |
2067 | int addr = temp_client->addr; | |
2068 | int err; | |
2069 | ||
2070 | /* Make sure the address is valid */ | |
66be6056 | 2071 | err = i2c_check_7bit_addr_validity_strict(addr); |
656b8761 | 2072 | if (err) { |
4735c98f JD |
2073 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
2074 | addr); | |
656b8761 | 2075 | return err; |
4735c98f JD |
2076 | } |
2077 | ||
9bccc70a | 2078 | /* Skip if already in use (7 bit, no need to encode flags) */ |
3b5f794b | 2079 | if (i2c_check_addr_busy(adapter, addr)) |
4735c98f JD |
2080 | return 0; |
2081 | ||
ccfbbd08 | 2082 | /* Make sure there is something at this address */ |
63e4e802 JD |
2083 | if (!i2c_default_probe(adapter, addr)) |
2084 | return 0; | |
4735c98f JD |
2085 | |
2086 | /* Finally call the custom detection function */ | |
2087 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
2088 | info.addr = addr; | |
310ec792 | 2089 | err = driver->detect(temp_client, &info); |
4735c98f JD |
2090 | if (err) { |
2091 | /* -ENODEV is returned if the detection fails. We catch it | |
2092 | here as this isn't an error. */ | |
2093 | return err == -ENODEV ? 0 : err; | |
2094 | } | |
2095 | ||
2096 | /* Consistency check */ | |
2097 | if (info.type[0] == '\0') { | |
b93d3d37 AS |
2098 | dev_err(&adapter->dev, |
2099 | "%s detection function provided no name for 0x%x\n", | |
2100 | driver->driver.name, addr); | |
4735c98f JD |
2101 | } else { |
2102 | struct i2c_client *client; | |
2103 | ||
2104 | /* Detection succeeded, instantiate the device */ | |
0c176170 WS |
2105 | if (adapter->class & I2C_CLASS_DEPRECATED) |
2106 | dev_warn(&adapter->dev, | |
2107 | "This adapter will soon drop class based instantiation of devices. " | |
2108 | "Please make sure client 0x%02x gets instantiated by other means. " | |
2109 | "Check 'Documentation/i2c/instantiating-devices' for details.\n", | |
2110 | info.addr); | |
2111 | ||
4735c98f JD |
2112 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", |
2113 | info.type, info.addr); | |
2114 | client = i2c_new_device(adapter, &info); | |
2115 | if (client) | |
2116 | list_add_tail(&client->detected, &driver->clients); | |
2117 | else | |
2118 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
2119 | info.type, info.addr); | |
2120 | } | |
2121 | return 0; | |
2122 | } | |
2123 | ||
2124 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
2125 | { | |
c3813d6a | 2126 | const unsigned short *address_list; |
4735c98f JD |
2127 | struct i2c_client *temp_client; |
2128 | int i, err = 0; | |
2129 | int adap_id = i2c_adapter_id(adapter); | |
2130 | ||
c3813d6a JD |
2131 | address_list = driver->address_list; |
2132 | if (!driver->detect || !address_list) | |
4735c98f JD |
2133 | return 0; |
2134 | ||
45552272 WS |
2135 | /* Warn that the adapter lost class based instantiation */ |
2136 | if (adapter->class == I2C_CLASS_DEPRECATED) { | |
2137 | dev_dbg(&adapter->dev, | |
b93d3d37 AS |
2138 | "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. " |
2139 | "If you need it, check 'Documentation/i2c/instantiating-devices' for alternatives.\n", | |
45552272 WS |
2140 | driver->driver.name); |
2141 | return 0; | |
2142 | } | |
2143 | ||
51b54ba9 JD |
2144 | /* Stop here if the classes do not match */ |
2145 | if (!(adapter->class & driver->class)) | |
2146 | return 0; | |
2147 | ||
4735c98f JD |
2148 | /* Set up a temporary client to help detect callback */ |
2149 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
2150 | if (!temp_client) | |
2151 | return -ENOMEM; | |
2152 | temp_client->adapter = adapter; | |
2153 | ||
c3813d6a | 2154 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
b93d3d37 AS |
2155 | dev_dbg(&adapter->dev, |
2156 | "found normal entry for adapter %d, addr 0x%02x\n", | |
2157 | adap_id, address_list[i]); | |
c3813d6a | 2158 | temp_client->addr = address_list[i]; |
ccfbbd08 | 2159 | err = i2c_detect_address(temp_client, driver); |
51b54ba9 JD |
2160 | if (unlikely(err)) |
2161 | break; | |
4735c98f JD |
2162 | } |
2163 | ||
4735c98f JD |
2164 | kfree(temp_client); |
2165 | return err; | |
2166 | } | |
2167 | ||
d44f19d5 JD |
2168 | int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) |
2169 | { | |
2170 | return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
2171 | I2C_SMBUS_QUICK, NULL) >= 0; | |
2172 | } | |
2173 | EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); | |
2174 | ||
12b5053a JD |
2175 | struct i2c_client * |
2176 | i2c_new_probed_device(struct i2c_adapter *adap, | |
2177 | struct i2c_board_info *info, | |
9a94241a JD |
2178 | unsigned short const *addr_list, |
2179 | int (*probe)(struct i2c_adapter *, unsigned short addr)) | |
12b5053a JD |
2180 | { |
2181 | int i; | |
2182 | ||
8031d79b | 2183 | if (!probe) |
9a94241a | 2184 | probe = i2c_default_probe; |
12b5053a | 2185 | |
12b5053a JD |
2186 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
2187 | /* Check address validity */ | |
66be6056 | 2188 | if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) { |
b93d3d37 AS |
2189 | dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n", |
2190 | addr_list[i]); | |
12b5053a JD |
2191 | continue; |
2192 | } | |
2193 | ||
9bccc70a | 2194 | /* Check address availability (7 bit, no need to encode flags) */ |
3b5f794b | 2195 | if (i2c_check_addr_busy(adap, addr_list[i])) { |
b93d3d37 AS |
2196 | dev_dbg(&adap->dev, |
2197 | "Address 0x%02x already in use, not probing\n", | |
2198 | addr_list[i]); | |
12b5053a JD |
2199 | continue; |
2200 | } | |
2201 | ||
63e4e802 | 2202 | /* Test address responsiveness */ |
9a94241a | 2203 | if (probe(adap, addr_list[i])) |
63e4e802 | 2204 | break; |
12b5053a | 2205 | } |
12b5053a JD |
2206 | |
2207 | if (addr_list[i] == I2C_CLIENT_END) { | |
2208 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
2209 | return NULL; | |
2210 | } | |
2211 | ||
2212 | info->addr = addr_list[i]; | |
2213 | return i2c_new_device(adap, info); | |
2214 | } | |
2215 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
2216 | ||
d735b34d | 2217 | struct i2c_adapter *i2c_get_adapter(int nr) |
1da177e4 | 2218 | { |
1da177e4 | 2219 | struct i2c_adapter *adapter; |
438d6c2c | 2220 | |
caada32a | 2221 | mutex_lock(&core_lock); |
d735b34d | 2222 | adapter = idr_find(&i2c_adapter_idr, nr); |
611e12ea VZ |
2223 | if (!adapter) |
2224 | goto exit; | |
2225 | ||
2226 | if (try_module_get(adapter->owner)) | |
2227 | get_device(&adapter->dev); | |
2228 | else | |
a0920e10 MH |
2229 | adapter = NULL; |
2230 | ||
611e12ea | 2231 | exit: |
caada32a | 2232 | mutex_unlock(&core_lock); |
a0920e10 | 2233 | return adapter; |
1da177e4 | 2234 | } |
c0564606 | 2235 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
2236 | |
2237 | void i2c_put_adapter(struct i2c_adapter *adap) | |
2238 | { | |
611e12ea VZ |
2239 | if (!adap) |
2240 | return; | |
2241 | ||
2242 | put_device(&adap->dev); | |
2243 | module_put(adap->owner); | |
1da177e4 | 2244 | } |
c0564606 | 2245 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 | 2246 | |
e94bc5d1 WS |
2247 | /** |
2248 | * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg | |
2249 | * @msg: the message to be checked | |
2250 | * @threshold: the minimum number of bytes for which using DMA makes sense | |
2251 | * | |
2252 | * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO. | |
2253 | * Or a valid pointer to be used with DMA. After use, release it by | |
2254 | * calling i2c_release_dma_safe_msg_buf(). | |
2255 | * | |
2256 | * This function must only be called from process context! | |
2257 | */ | |
2258 | u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold) | |
2259 | { | |
2260 | if (msg->len < threshold) | |
2261 | return NULL; | |
2262 | ||
2263 | if (msg->flags & I2C_M_DMA_SAFE) | |
2264 | return msg->buf; | |
2265 | ||
2266 | pr_debug("using bounce buffer for addr=0x%02x, len=%d\n", | |
2267 | msg->addr, msg->len); | |
2268 | ||
2269 | if (msg->flags & I2C_M_RD) | |
2270 | return kzalloc(msg->len, GFP_KERNEL); | |
2271 | else | |
2272 | return kmemdup(msg->buf, msg->len, GFP_KERNEL); | |
2273 | } | |
2274 | EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf); | |
2275 | ||
2276 | /** | |
2277 | * i2c_release_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg | |
2278 | * @msg: the message to be synced with | |
2279 | * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL. | |
2280 | */ | |
2281 | void i2c_release_dma_safe_msg_buf(struct i2c_msg *msg, u8 *buf) | |
2282 | { | |
2283 | if (!buf || buf == msg->buf) | |
2284 | return; | |
2285 | ||
2286 | if (msg->flags & I2C_M_RD) | |
2287 | memcpy(msg->buf, buf, msg->len); | |
2288 | ||
2289 | kfree(buf); | |
2290 | } | |
2291 | EXPORT_SYMBOL_GPL(i2c_release_dma_safe_msg_buf); | |
2292 | ||
1da177e4 LT |
2293 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); |
2294 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
2295 | MODULE_LICENSE("GPL"); |