Branch data Line data Source code
1 : : // SPDX-License-Identifier: GPL-2.0-or-later
2 : : /*
3 : : * Linux I2C core
4 : : *
5 : : * Copyright (C) 1995-99 Simon G. Vogl
6 : : * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>
7 : : * Mux support by Rodolfo Giometti <giometti@enneenne.com> and
8 : : * Michael Lawnick <michael.lawnick.ext@nsn.com>
9 : : *
10 : : * Copyright (C) 2013-2017 Wolfram Sang <wsa@the-dreams.de>
11 : : */
12 : :
13 : : #define pr_fmt(fmt) "i2c-core: " fmt
14 : :
15 : : #include <dt-bindings/i2c/i2c.h>
16 : : #include <linux/acpi.h>
17 : : #include <linux/clk/clk-conf.h>
18 : : #include <linux/completion.h>
19 : : #include <linux/delay.h>
20 : : #include <linux/err.h>
21 : : #include <linux/errno.h>
22 : : #include <linux/gpio/consumer.h>
23 : : #include <linux/i2c.h>
24 : : #include <linux/i2c-smbus.h>
25 : : #include <linux/idr.h>
26 : : #include <linux/init.h>
27 : : #include <linux/irqflags.h>
28 : : #include <linux/jump_label.h>
29 : : #include <linux/kernel.h>
30 : : #include <linux/module.h>
31 : : #include <linux/mutex.h>
32 : : #include <linux/of_device.h>
33 : : #include <linux/of.h>
34 : : #include <linux/of_irq.h>
35 : : #include <linux/pm_domain.h>
36 : : #include <linux/pm_runtime.h>
37 : : #include <linux/pm_wakeirq.h>
38 : : #include <linux/property.h>
39 : : #include <linux/rwsem.h>
40 : : #include <linux/slab.h>
41 : :
42 : : #include "i2c-core.h"
43 : :
44 : : #define CREATE_TRACE_POINTS
45 : : #include <trace/events/i2c.h>
46 : :
47 : : #define I2C_ADDR_OFFSET_TEN_BIT 0xa000
48 : : #define I2C_ADDR_OFFSET_SLAVE 0x1000
49 : :
50 : : #define I2C_ADDR_7BITS_MAX 0x77
51 : : #define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1)
52 : :
53 : : #define I2C_ADDR_DEVICE_ID 0x7c
54 : :
55 : : /*
56 : : * core_lock protects i2c_adapter_idr, and guarantees that device detection,
57 : : * deletion of detected devices are serialized
58 : : */
59 : : static DEFINE_MUTEX(core_lock);
60 : : static DEFINE_IDR(i2c_adapter_idr);
61 : :
62 : : static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
63 : :
64 : : static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key);
65 : : static bool is_registered;
66 : :
67 : 0 : int i2c_transfer_trace_reg(void)
68 : : {
69 : 0 : static_branch_inc(&i2c_trace_msg_key);
70 : 0 : return 0;
71 : : }
72 : :
73 : 0 : void i2c_transfer_trace_unreg(void)
74 : : {
75 : 0 : static_branch_dec(&i2c_trace_msg_key);
76 : 0 : }
77 : :
78 : 0 : const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
79 : : const struct i2c_client *client)
80 : : {
81 [ # # ]: 0 : if (!(id && client))
82 : : return NULL;
83 : :
84 [ # # ]: 0 : while (id->name[0]) {
85 [ # # ]: 0 : if (strcmp(client->name, id->name) == 0)
86 : 0 : return id;
87 : 0 : id++;
88 : : }
89 : : return NULL;
90 : : }
91 : : EXPORT_SYMBOL_GPL(i2c_match_id);
92 : :
93 : 0 : static int i2c_device_match(struct device *dev, struct device_driver *drv)
94 : : {
95 : : struct i2c_client *client = i2c_verify_client(dev);
96 : : struct i2c_driver *driver;
97 : :
98 : :
99 : : /* Attempt an OF style match */
100 [ # # ]: 0 : if (i2c_of_match_device(drv->of_match_table, client))
101 : : return 1;
102 : :
103 : : /* Then ACPI style match */
104 : : if (acpi_driver_match_device(dev, drv))
105 : : return 1;
106 : :
107 : : driver = to_i2c_driver(drv);
108 : :
109 : : /* Finally an I2C match */
110 [ # # ]: 0 : if (i2c_match_id(driver->id_table, client))
111 : : return 1;
112 : :
113 : 0 : return 0;
114 : : }
115 : :
116 : 0 : static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
117 : : {
118 : : struct i2c_client *client = to_i2c_client(dev);
119 : : int rc;
120 : :
121 : 0 : rc = of_device_uevent_modalias(dev, env);
122 [ # # ]: 0 : if (rc != -ENODEV)
123 : : return rc;
124 : :
125 : : rc = acpi_device_uevent_modalias(dev, env);
126 : : if (rc != -ENODEV)
127 : : return rc;
128 : :
129 : 0 : return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name);
130 : : }
131 : :
132 : : /* i2c bus recovery routines */
133 : 0 : static int get_scl_gpio_value(struct i2c_adapter *adap)
134 : : {
135 : 0 : return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod);
136 : : }
137 : :
138 : 0 : static void set_scl_gpio_value(struct i2c_adapter *adap, int val)
139 : : {
140 : 0 : gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val);
141 : 0 : }
142 : :
143 : 0 : static int get_sda_gpio_value(struct i2c_adapter *adap)
144 : : {
145 : 0 : return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod);
146 : : }
147 : :
148 : 0 : static void set_sda_gpio_value(struct i2c_adapter *adap, int val)
149 : : {
150 : 0 : gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val);
151 : 0 : }
152 : :
153 : 0 : static int i2c_generic_bus_free(struct i2c_adapter *adap)
154 : : {
155 : 0 : struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
156 : : int ret = -EOPNOTSUPP;
157 : :
158 [ # # ]: 0 : if (bri->get_bus_free)
159 : 0 : ret = bri->get_bus_free(adap);
160 [ # # ]: 0 : else if (bri->get_sda)
161 : 0 : ret = bri->get_sda(adap);
162 : :
163 [ # # ]: 0 : if (ret < 0)
164 : : return ret;
165 : :
166 [ # # ]: 0 : return ret ? 0 : -EBUSY;
167 : : }
168 : :
169 : : /*
170 : : * We are generating clock pulses. ndelay() determines durating of clk pulses.
171 : : * We will generate clock with rate 100 KHz and so duration of both clock levels
172 : : * is: delay in ns = (10^6 / 100) / 2
173 : : */
174 : : #define RECOVERY_NDELAY 5000
175 : : #define RECOVERY_CLK_CNT 9
176 : :
177 : 0 : int i2c_generic_scl_recovery(struct i2c_adapter *adap)
178 : : {
179 : 0 : struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
180 : : int i = 0, scl = 1, ret = 0;
181 : :
182 [ # # ]: 0 : if (bri->prepare_recovery)
183 : 0 : bri->prepare_recovery(adap);
184 : :
185 : : /*
186 : : * If we can set SDA, we will always create a STOP to ensure additional
187 : : * pulses will do no harm. This is achieved by letting SDA follow SCL
188 : : * half a cycle later. Check the 'incomplete_write_byte' fault injector
189 : : * for details. Note that we must honour tsu:sto, 4us, but lets use 5us
190 : : * here for simplicity.
191 : : */
192 : 0 : bri->set_scl(adap, scl);
193 : 0 : ndelay(RECOVERY_NDELAY);
194 [ # # ]: 0 : if (bri->set_sda)
195 : 0 : bri->set_sda(adap, scl);
196 : 0 : ndelay(RECOVERY_NDELAY / 2);
197 : :
198 : : /*
199 : : * By this time SCL is high, as we need to give 9 falling-rising edges
200 : : */
201 [ # # ]: 0 : while (i++ < RECOVERY_CLK_CNT * 2) {
202 [ # # ]: 0 : if (scl) {
203 : : /* SCL shouldn't be low here */
204 [ # # ]: 0 : if (!bri->get_scl(adap)) {
205 : 0 : dev_err(&adap->dev,
206 : : "SCL is stuck low, exit recovery\n");
207 : : ret = -EBUSY;
208 : 0 : break;
209 : : }
210 : : }
211 : :
212 : 0 : scl = !scl;
213 : 0 : bri->set_scl(adap, scl);
214 : : /* Creating STOP again, see above */
215 [ # # ]: 0 : if (scl) {
216 : : /* Honour minimum tsu:sto */
217 : 0 : ndelay(RECOVERY_NDELAY);
218 : : } else {
219 : : /* Honour minimum tf and thd:dat */
220 : 0 : ndelay(RECOVERY_NDELAY / 2);
221 : : }
222 [ # # ]: 0 : if (bri->set_sda)
223 : 0 : bri->set_sda(adap, scl);
224 : 0 : ndelay(RECOVERY_NDELAY / 2);
225 : :
226 [ # # ]: 0 : if (scl) {
227 : 0 : ret = i2c_generic_bus_free(adap);
228 [ # # ]: 0 : if (ret == 0)
229 : : break;
230 : : }
231 : : }
232 : :
233 : : /* If we can't check bus status, assume recovery worked */
234 [ # # ]: 0 : if (ret == -EOPNOTSUPP)
235 : : ret = 0;
236 : :
237 [ # # ]: 0 : if (bri->unprepare_recovery)
238 : 0 : bri->unprepare_recovery(adap);
239 : :
240 : 0 : return ret;
241 : : }
242 : : EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery);
243 : :
244 : 0 : int i2c_recover_bus(struct i2c_adapter *adap)
245 : : {
246 [ # # ]: 0 : if (!adap->bus_recovery_info)
247 : : return -EOPNOTSUPP;
248 : :
249 : : dev_dbg(&adap->dev, "Trying i2c bus recovery\n");
250 : 0 : return adap->bus_recovery_info->recover_bus(adap);
251 : : }
252 : : EXPORT_SYMBOL_GPL(i2c_recover_bus);
253 : :
254 : 0 : static void i2c_init_recovery(struct i2c_adapter *adap)
255 : : {
256 : 0 : struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
257 : : char *err_str;
258 : :
259 [ # # ]: 0 : if (!bri)
260 : : return;
261 : :
262 [ # # ]: 0 : if (!bri->recover_bus) {
263 : : err_str = "no recover_bus() found";
264 : : goto err;
265 : : }
266 : :
267 [ # # # # ]: 0 : if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) {
268 : 0 : bri->get_scl = get_scl_gpio_value;
269 : 0 : bri->set_scl = set_scl_gpio_value;
270 [ # # ]: 0 : if (bri->sda_gpiod) {
271 : 0 : bri->get_sda = get_sda_gpio_value;
272 : : /* FIXME: add proper flag instead of '0' once available */
273 [ # # ]: 0 : if (gpiod_get_direction(bri->sda_gpiod) == 0)
274 : 0 : bri->set_sda = set_sda_gpio_value;
275 : : }
276 : : return;
277 : : }
278 : :
279 [ # # ]: 0 : if (bri->recover_bus == i2c_generic_scl_recovery) {
280 : : /* Generic SCL recovery */
281 [ # # # # ]: 0 : if (!bri->set_scl || !bri->get_scl) {
282 : : err_str = "no {get|set}_scl() found";
283 : : goto err;
284 : : }
285 [ # # # # ]: 0 : if (!bri->set_sda && !bri->get_sda) {
286 : : err_str = "either get_sda() or set_sda() needed";
287 : : goto err;
288 : : }
289 : : }
290 : :
291 : : return;
292 : : err:
293 : 0 : dev_err(&adap->dev, "Not using recovery: %s\n", err_str);
294 : 0 : adap->bus_recovery_info = NULL;
295 : : }
296 : :
297 : 0 : static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client)
298 : : {
299 : 0 : struct i2c_adapter *adap = client->adapter;
300 : : unsigned int irq;
301 : :
302 [ # # ]: 0 : if (!adap->host_notify_domain)
303 : : return -ENXIO;
304 : :
305 [ # # ]: 0 : if (client->flags & I2C_CLIENT_TEN)
306 : : return -EINVAL;
307 : :
308 : 0 : irq = irq_create_mapping(adap->host_notify_domain, client->addr);
309 : :
310 [ # # ]: 0 : return irq > 0 ? irq : -ENXIO;
311 : : }
312 : :
313 : 0 : static int i2c_device_probe(struct device *dev)
314 : : {
315 : : struct i2c_client *client = i2c_verify_client(dev);
316 : : struct i2c_driver *driver;
317 : : int status;
318 : :
319 [ # # ]: 0 : if (!client)
320 : : return 0;
321 : :
322 : 0 : driver = to_i2c_driver(dev->driver);
323 : :
324 : 0 : client->irq = client->init_irq;
325 : :
326 [ # # # # ]: 0 : if (!client->irq && !driver->disable_i2c_core_irq_mapping) {
327 : : int irq = -ENOENT;
328 : :
329 [ # # ]: 0 : if (client->flags & I2C_CLIENT_HOST_NOTIFY) {
330 : : dev_dbg(dev, "Using Host Notify IRQ\n");
331 : : /* Keep adapter active when Host Notify is required */
332 : 0 : pm_runtime_get_sync(&client->adapter->dev);
333 : 0 : irq = i2c_smbus_host_notify_to_irq(client);
334 [ # # ]: 0 : } else if (dev->of_node) {
335 : 0 : irq = of_irq_get_byname(dev->of_node, "irq");
336 [ # # ]: 0 : if (irq == -EINVAL || irq == -ENODATA)
337 : 0 : irq = of_irq_get(dev->of_node, 0);
338 : : } else if (ACPI_COMPANION(dev)) {
339 : : irq = i2c_acpi_get_irq(client);
340 : : }
341 [ # # ]: 0 : if (irq == -EPROBE_DEFER) {
342 : : status = irq;
343 : : goto put_sync_adapter;
344 : : }
345 : :
346 [ # # ]: 0 : if (irq < 0)
347 : : irq = 0;
348 : :
349 : 0 : client->irq = irq;
350 : : }
351 : :
352 : : /*
353 : : * An I2C ID table is not mandatory, if and only if, a suitable OF
354 : : * or ACPI ID table is supplied for the probing device.
355 : : */
356 [ # # ]: 0 : if (!driver->id_table &&
357 [ # # ]: 0 : !i2c_acpi_match_device(dev->driver->acpi_match_table, client) &&
358 : 0 : !i2c_of_match_device(dev->driver->of_match_table, client)) {
359 : : status = -ENODEV;
360 : : goto put_sync_adapter;
361 : : }
362 : :
363 [ # # ]: 0 : if (client->flags & I2C_CLIENT_WAKE) {
364 : : int wakeirq;
365 : :
366 : 0 : wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
367 [ # # ]: 0 : if (wakeirq == -EPROBE_DEFER) {
368 : : status = wakeirq;
369 : : goto put_sync_adapter;
370 : : }
371 : :
372 : : device_init_wakeup(&client->dev, true);
373 : :
374 [ # # # # ]: 0 : if (wakeirq > 0 && wakeirq != client->irq)
375 : 0 : status = dev_pm_set_dedicated_wake_irq(dev, wakeirq);
376 [ # # ]: 0 : else if (client->irq > 0)
377 : 0 : status = dev_pm_set_wake_irq(dev, client->irq);
378 : : else
379 : : status = 0;
380 : :
381 [ # # ]: 0 : if (status)
382 : 0 : dev_warn(&client->dev, "failed to set up wakeup irq\n");
383 : : }
384 : :
385 : : dev_dbg(dev, "probe\n");
386 : :
387 : 0 : status = of_clk_set_defaults(dev->of_node, false);
388 [ # # ]: 0 : if (status < 0)
389 : : goto err_clear_wakeup_irq;
390 : :
391 : 0 : status = dev_pm_domain_attach(&client->dev, true);
392 [ # # ]: 0 : if (status)
393 : : goto err_clear_wakeup_irq;
394 : :
395 : : /*
396 : : * When there are no more users of probe(),
397 : : * rename probe_new to probe.
398 : : */
399 [ # # ]: 0 : if (driver->probe_new)
400 : 0 : status = driver->probe_new(client);
401 [ # # ]: 0 : else if (driver->probe)
402 : 0 : status = driver->probe(client,
403 : : i2c_match_id(driver->id_table, client));
404 : : else
405 : : status = -EINVAL;
406 : :
407 [ # # ]: 0 : if (status)
408 : : goto err_detach_pm_domain;
409 : :
410 : : return 0;
411 : :
412 : : err_detach_pm_domain:
413 : 0 : dev_pm_domain_detach(&client->dev, true);
414 : : err_clear_wakeup_irq:
415 : 0 : dev_pm_clear_wake_irq(&client->dev);
416 : : device_init_wakeup(&client->dev, false);
417 : : put_sync_adapter:
418 [ # # ]: 0 : if (client->flags & I2C_CLIENT_HOST_NOTIFY)
419 : 0 : pm_runtime_put_sync(&client->adapter->dev);
420 : :
421 : 0 : return status;
422 : : }
423 : :
424 : 0 : static int i2c_device_remove(struct device *dev)
425 : : {
426 : : struct i2c_client *client = i2c_verify_client(dev);
427 : : struct i2c_driver *driver;
428 : : int status = 0;
429 : :
430 [ # # # # ]: 0 : if (!client || !dev->driver)
431 : : return 0;
432 : :
433 : : driver = to_i2c_driver(dev->driver);
434 [ # # ]: 0 : if (driver->remove) {
435 : : dev_dbg(dev, "remove\n");
436 : 0 : status = driver->remove(client);
437 : : }
438 : :
439 : 0 : dev_pm_domain_detach(&client->dev, true);
440 : :
441 : 0 : dev_pm_clear_wake_irq(&client->dev);
442 : : device_init_wakeup(&client->dev, false);
443 : :
444 : 0 : client->irq = 0;
445 [ # # ]: 0 : if (client->flags & I2C_CLIENT_HOST_NOTIFY)
446 : 0 : pm_runtime_put(&client->adapter->dev);
447 : :
448 : 0 : return status;
449 : : }
450 : :
451 : 0 : static void i2c_device_shutdown(struct device *dev)
452 : : {
453 : : struct i2c_client *client = i2c_verify_client(dev);
454 : : struct i2c_driver *driver;
455 : :
456 [ # # # # ]: 0 : if (!client || !dev->driver)
457 : 0 : return;
458 : : driver = to_i2c_driver(dev->driver);
459 [ # # ]: 0 : if (driver->shutdown)
460 : 0 : driver->shutdown(client);
461 : : }
462 : :
463 : 0 : static void i2c_client_dev_release(struct device *dev)
464 : : {
465 : 0 : kfree(to_i2c_client(dev));
466 : 0 : }
467 : :
468 : : static ssize_t
469 : 0 : show_name(struct device *dev, struct device_attribute *attr, char *buf)
470 : : {
471 [ # # ]: 0 : return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?
472 : : to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);
473 : : }
474 : : static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
475 : :
476 : : static ssize_t
477 : 0 : show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
478 : : {
479 : : struct i2c_client *client = to_i2c_client(dev);
480 : : int len;
481 : :
482 : 0 : len = of_device_modalias(dev, buf, PAGE_SIZE);
483 [ # # ]: 0 : if (len != -ENODEV)
484 : : return len;
485 : :
486 : : len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
487 : : if (len != -ENODEV)
488 : : return len;
489 : :
490 : 0 : return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
491 : : }
492 : : static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
493 : :
494 : : static struct attribute *i2c_dev_attrs[] = {
495 : : &dev_attr_name.attr,
496 : : /* modalias helps coldplug: modprobe $(cat .../modalias) */
497 : : &dev_attr_modalias.attr,
498 : : NULL
499 : : };
500 : : ATTRIBUTE_GROUPS(i2c_dev);
501 : :
502 : : struct bus_type i2c_bus_type = {
503 : : .name = "i2c",
504 : : .match = i2c_device_match,
505 : : .probe = i2c_device_probe,
506 : : .remove = i2c_device_remove,
507 : : .shutdown = i2c_device_shutdown,
508 : : };
509 : : EXPORT_SYMBOL_GPL(i2c_bus_type);
510 : :
511 : : struct device_type i2c_client_type = {
512 : : .groups = i2c_dev_groups,
513 : : .uevent = i2c_device_uevent,
514 : : .release = i2c_client_dev_release,
515 : : };
516 : : EXPORT_SYMBOL_GPL(i2c_client_type);
517 : :
518 : :
519 : : /**
520 : : * i2c_verify_client - return parameter as i2c_client, or NULL
521 : : * @dev: device, probably from some driver model iterator
522 : : *
523 : : * When traversing the driver model tree, perhaps using driver model
524 : : * iterators like @device_for_each_child(), you can't assume very much
525 : : * about the nodes you find. Use this function to avoid oopses caused
526 : : * by wrongly treating some non-I2C device as an i2c_client.
527 : : */
528 : 0 : struct i2c_client *i2c_verify_client(struct device *dev)
529 : : {
530 : 0 : return (dev->type == &i2c_client_type)
531 : 0 : ? to_i2c_client(dev)
532 [ # # # # : 0 : : NULL;
# # # # #
# # # # #
# # # # ]
533 : : }
534 : : EXPORT_SYMBOL(i2c_verify_client);
535 : :
536 : :
537 : : /* Return a unique address which takes the flags of the client into account */
538 : : static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client)
539 : : {
540 : 0 : unsigned short addr = client->addr;
541 : :
542 : : /* For some client flags, add an arbitrary offset to avoid collisions */
543 [ # # # # : 0 : if (client->flags & I2C_CLIENT_TEN)
# # # # ]
544 : 0 : addr |= I2C_ADDR_OFFSET_TEN_BIT;
545 : :
546 [ # # # # : 0 : if (client->flags & I2C_CLIENT_SLAVE)
# # # # ]
547 : 0 : addr |= I2C_ADDR_OFFSET_SLAVE;
548 : :
549 : : return addr;
550 : : }
551 : :
552 : : /* This is a permissive address validity check, I2C address map constraints
553 : : * are purposely not enforced, except for the general call address. */
554 : : static int i2c_check_addr_validity(unsigned int addr, unsigned short flags)
555 : : {
556 [ # # ]: 0 : if (flags & I2C_CLIENT_TEN) {
557 : : /* 10-bit address, all values are valid */
558 [ # # ]: 0 : if (addr > 0x3ff)
559 : : return -EINVAL;
560 : : } else {
561 : : /* 7-bit address, reject the general call address */
562 [ # # ]: 0 : if (addr == 0x00 || addr > 0x7f)
563 : : return -EINVAL;
564 : : }
565 : : return 0;
566 : : }
567 : :
568 : : /* And this is a strict address validity check, used when probing. If a
569 : : * device uses a reserved address, then it shouldn't be probed. 7-bit
570 : : * addressing is assumed, 10-bit address devices are rare and should be
571 : : * explicitly enumerated. */
572 : 0 : int i2c_check_7bit_addr_validity_strict(unsigned short addr)
573 : : {
574 : : /*
575 : : * Reserved addresses per I2C specification:
576 : : * 0x00 General call address / START byte
577 : : * 0x01 CBUS address
578 : : * 0x02 Reserved for different bus format
579 : : * 0x03 Reserved for future purposes
580 : : * 0x04-0x07 Hs-mode master code
581 : : * 0x78-0x7b 10-bit slave addressing
582 : : * 0x7c-0x7f Reserved for future purposes
583 : : */
584 [ # # # # : 0 : if (addr < 0x08 || addr > 0x77)
# # ]
585 : : return -EINVAL;
586 : 0 : return 0;
587 : : }
588 : :
589 : 0 : static int __i2c_check_addr_busy(struct device *dev, void *addrp)
590 : : {
591 : : struct i2c_client *client = i2c_verify_client(dev);
592 : 0 : int addr = *(int *)addrp;
593 : :
594 [ # # # # ]: 0 : if (client && i2c_encode_flags_to_addr(client) == addr)
595 : : return -EBUSY;
596 : 0 : return 0;
597 : : }
598 : :
599 : : /* walk up mux tree */
600 : 0 : static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)
601 : : {
602 : : struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
603 : : int result;
604 : :
605 : 0 : result = device_for_each_child(&adapter->dev, &addr,
606 : : __i2c_check_addr_busy);
607 : :
608 [ # # ]: 0 : if (!result && parent)
609 : 0 : result = i2c_check_mux_parents(parent, addr);
610 : :
611 : 0 : return result;
612 : : }
613 : :
614 : : /* recurse down mux tree */
615 : 0 : static int i2c_check_mux_children(struct device *dev, void *addrp)
616 : : {
617 : : int result;
618 : :
619 [ # # ]: 0 : if (dev->type == &i2c_adapter_type)
620 : 0 : result = device_for_each_child(dev, addrp,
621 : : i2c_check_mux_children);
622 : : else
623 : 0 : result = __i2c_check_addr_busy(dev, addrp);
624 : :
625 : 0 : return result;
626 : : }
627 : :
628 : 0 : static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
629 : : {
630 : : struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
631 : : int result = 0;
632 : :
633 [ # # ]: 0 : if (parent)
634 : 0 : result = i2c_check_mux_parents(parent, addr);
635 : :
636 [ # # ]: 0 : if (!result)
637 : 0 : result = device_for_each_child(&adapter->dev, &addr,
638 : : i2c_check_mux_children);
639 : :
640 : 0 : return result;
641 : : }
642 : :
643 : : /**
644 : : * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment
645 : : * @adapter: Target I2C bus segment
646 : : * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
647 : : * locks only this branch in the adapter tree
648 : : */
649 : 0 : static void i2c_adapter_lock_bus(struct i2c_adapter *adapter,
650 : : unsigned int flags)
651 : : {
652 : 0 : rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter));
653 : 0 : }
654 : :
655 : : /**
656 : : * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment
657 : : * @adapter: Target I2C bus segment
658 : : * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT
659 : : * trylocks only this branch in the adapter tree
660 : : */
661 : 0 : static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter,
662 : : unsigned int flags)
663 : : {
664 : 0 : return rt_mutex_trylock(&adapter->bus_lock);
665 : : }
666 : :
667 : : /**
668 : : * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment
669 : : * @adapter: Target I2C bus segment
670 : : * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
671 : : * unlocks only this branch in the adapter tree
672 : : */
673 : 0 : static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter,
674 : : unsigned int flags)
675 : : {
676 : 0 : rt_mutex_unlock(&adapter->bus_lock);
677 : 0 : }
678 : :
679 : 0 : static void i2c_dev_set_name(struct i2c_adapter *adap,
680 : : struct i2c_client *client,
681 : : struct i2c_board_info const *info)
682 : : {
683 : : struct acpi_device *adev = ACPI_COMPANION(&client->dev);
684 : :
685 [ # # # # ]: 0 : if (info && info->dev_name) {
686 : 0 : dev_set_name(&client->dev, "i2c-%s", info->dev_name);
687 : 0 : return;
688 : : }
689 : :
690 : : if (adev) {
691 : : dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev));
692 : : return;
693 : : }
694 : :
695 : 0 : dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
696 : : i2c_encode_flags_to_addr(client));
697 : : }
698 : :
699 : 0 : int i2c_dev_irq_from_resources(const struct resource *resources,
700 : : unsigned int num_resources)
701 : : {
702 : : struct irq_data *irqd;
703 : : int i;
704 : :
705 [ # # ]: 0 : for (i = 0; i < num_resources; i++) {
706 : 0 : const struct resource *r = &resources[i];
707 : :
708 [ # # ]: 0 : if (resource_type(r) != IORESOURCE_IRQ)
709 : 0 : continue;
710 : :
711 [ # # ]: 0 : if (r->flags & IORESOURCE_BITS) {
712 : 0 : irqd = irq_get_irq_data(r->start);
713 [ # # ]: 0 : if (!irqd)
714 : : break;
715 : :
716 : 0 : irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
717 : : }
718 : :
719 : 0 : return r->start;
720 : : }
721 : :
722 : : return 0;
723 : : }
724 : :
725 : : /**
726 : : * i2c_new_client_device - instantiate an i2c device
727 : : * @adap: the adapter managing the device
728 : : * @info: describes one I2C device; bus_num is ignored
729 : : * Context: can sleep
730 : : *
731 : : * Create an i2c device. Binding is handled through driver model
732 : : * probe()/remove() methods. A driver may be bound to this device when we
733 : : * return from this function, or any later moment (e.g. maybe hotplugging will
734 : : * load the driver module). This call is not appropriate for use by mainboard
735 : : * initialization logic, which usually runs during an arch_initcall() long
736 : : * before any i2c_adapter could exist.
737 : : *
738 : : * This returns the new i2c client, which may be saved for later use with
739 : : * i2c_unregister_device(); or an ERR_PTR to describe the error.
740 : : */
741 : : struct i2c_client *
742 : 0 : i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
743 : : {
744 : : struct i2c_client *client;
745 : : int status;
746 : :
747 : 0 : client = kzalloc(sizeof *client, GFP_KERNEL);
748 [ # # ]: 0 : if (!client)
749 : : return ERR_PTR(-ENOMEM);
750 : :
751 : 0 : client->adapter = adap;
752 : :
753 : 0 : client->dev.platform_data = info->platform_data;
754 : 0 : client->flags = info->flags;
755 : 0 : client->addr = info->addr;
756 : :
757 : 0 : client->init_irq = info->irq;
758 [ # # ]: 0 : if (!client->init_irq)
759 : 0 : client->init_irq = i2c_dev_irq_from_resources(info->resources,
760 : : info->num_resources);
761 : :
762 : 0 : strlcpy(client->name, info->type, sizeof(client->name));
763 : :
764 : 0 : status = i2c_check_addr_validity(client->addr, client->flags);
765 [ # # ]: 0 : if (status) {
766 [ # # ]: 0 : dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n",
767 : : client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr);
768 : 0 : goto out_err_silent;
769 : : }
770 : :
771 : : /* Check for address business */
772 : 0 : status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client));
773 [ # # ]: 0 : if (status)
774 : : goto out_err;
775 : :
776 : 0 : client->dev.parent = &client->adapter->dev;
777 : 0 : client->dev.bus = &i2c_bus_type;
778 : 0 : client->dev.type = &i2c_client_type;
779 : 0 : client->dev.of_node = of_node_get(info->of_node);
780 : 0 : client->dev.fwnode = info->fwnode;
781 : :
782 : 0 : i2c_dev_set_name(adap, client, info);
783 : :
784 [ # # ]: 0 : if (info->properties) {
785 : 0 : status = device_add_properties(&client->dev, info->properties);
786 [ # # ]: 0 : if (status) {
787 : 0 : dev_err(&adap->dev,
788 : : "Failed to add properties to client %s: %d\n",
789 : : client->name, status);
790 : 0 : goto out_err_put_of_node;
791 : : }
792 : : }
793 : :
794 : 0 : status = device_register(&client->dev);
795 [ # # ]: 0 : if (status)
796 : : goto out_free_props;
797 : :
798 : : dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
799 : : client->name, dev_name(&client->dev));
800 : :
801 : : return client;
802 : :
803 : : out_free_props:
804 [ # # ]: 0 : if (info->properties)
805 : 0 : device_remove_properties(&client->dev);
806 : : out_err_put_of_node:
807 : 0 : of_node_put(info->of_node);
808 : : out_err:
809 : 0 : dev_err(&adap->dev,
810 : : "Failed to register i2c client %s at 0x%02x (%d)\n",
811 : : client->name, client->addr, status);
812 : : out_err_silent:
813 : 0 : kfree(client);
814 : 0 : return ERR_PTR(status);
815 : : }
816 : : EXPORT_SYMBOL_GPL(i2c_new_client_device);
817 : :
818 : : /**
819 : : * i2c_new_device - instantiate an i2c device
820 : : * @adap: the adapter managing the device
821 : : * @info: describes one I2C device; bus_num is ignored
822 : : * Context: can sleep
823 : : *
824 : : * This deprecated function has the same functionality as
825 : : * @i2c_new_client_device, it just returns NULL instead of an ERR_PTR in case of
826 : : * an error for compatibility with current I2C API. It will be removed once all
827 : : * users are converted.
828 : : *
829 : : * This returns the new i2c client, which may be saved for later use with
830 : : * i2c_unregister_device(); or NULL to indicate an error.
831 : : */
832 : : struct i2c_client *
833 : 0 : i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
834 : : {
835 : : struct i2c_client *ret;
836 : :
837 : 0 : ret = i2c_new_client_device(adap, info);
838 [ # # # # : 0 : return IS_ERR(ret) ? NULL : ret;
# # # # ]
839 : : }
840 : : EXPORT_SYMBOL_GPL(i2c_new_device);
841 : :
842 : :
843 : : /**
844 : : * i2c_unregister_device - reverse effect of i2c_new_device()
845 : : * @client: value returned from i2c_new_device()
846 : : * Context: can sleep
847 : : */
848 : 0 : void i2c_unregister_device(struct i2c_client *client)
849 : : {
850 [ # # ]: 0 : if (IS_ERR_OR_NULL(client))
851 : 0 : return;
852 : :
853 [ # # ]: 0 : if (client->dev.of_node) {
854 : : of_node_clear_flag(client->dev.of_node, OF_POPULATED);
855 : 0 : of_node_put(client->dev.of_node);
856 : : }
857 : :
858 : : if (ACPI_COMPANION(&client->dev))
859 : : acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev));
860 : 0 : device_unregister(&client->dev);
861 : : }
862 : : EXPORT_SYMBOL_GPL(i2c_unregister_device);
863 : :
864 : :
865 : : static const struct i2c_device_id dummy_id[] = {
866 : : { "dummy", 0 },
867 : : { },
868 : : };
869 : :
870 : 0 : static int dummy_probe(struct i2c_client *client,
871 : : const struct i2c_device_id *id)
872 : : {
873 : 0 : return 0;
874 : : }
875 : :
876 : 0 : static int dummy_remove(struct i2c_client *client)
877 : : {
878 : 0 : return 0;
879 : : }
880 : :
881 : : static struct i2c_driver dummy_driver = {
882 : : .driver.name = "dummy",
883 : : .probe = dummy_probe,
884 : : .remove = dummy_remove,
885 : : .id_table = dummy_id,
886 : : };
887 : :
888 : : /**
889 : : * i2c_new_dummy_device - return a new i2c device bound to a dummy driver
890 : : * @adapter: the adapter managing the device
891 : : * @address: seven bit address to be used
892 : : * Context: can sleep
893 : : *
894 : : * This returns an I2C client bound to the "dummy" driver, intended for use
895 : : * with devices that consume multiple addresses. Examples of such chips
896 : : * include various EEPROMS (like 24c04 and 24c08 models).
897 : : *
898 : : * These dummy devices have two main uses. First, most I2C and SMBus calls
899 : : * except i2c_transfer() need a client handle; the dummy will be that handle.
900 : : * And second, this prevents the specified address from being bound to a
901 : : * different driver.
902 : : *
903 : : * This returns the new i2c client, which should be saved for later use with
904 : : * i2c_unregister_device(); or an ERR_PTR to describe the error.
905 : : */
906 : 0 : struct i2c_client *i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address)
907 : : {
908 : 0 : struct i2c_board_info info = {
909 : : I2C_BOARD_INFO("dummy", address),
910 : : };
911 : :
912 : 0 : return i2c_new_client_device(adapter, &info);
913 : : }
914 : : EXPORT_SYMBOL_GPL(i2c_new_dummy_device);
915 : :
916 : : /**
917 : : * i2c_new_dummy - return a new i2c device bound to a dummy driver
918 : : * @adapter: the adapter managing the device
919 : : * @address: seven bit address to be used
920 : : * Context: can sleep
921 : : *
922 : : * This deprecated function has the same functionality as @i2c_new_dummy_device,
923 : : * it just returns NULL instead of an ERR_PTR in case of an error for
924 : : * compatibility with current I2C API. It will be removed once all users are
925 : : * converted.
926 : : *
927 : : * This returns the new i2c client, which should be saved for later use with
928 : : * i2c_unregister_device(); or NULL to indicate an error.
929 : : */
930 : 0 : struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
931 : : {
932 : : struct i2c_client *ret;
933 : :
934 : 0 : ret = i2c_new_dummy_device(adapter, address);
935 [ # # ]: 0 : return IS_ERR(ret) ? NULL : ret;
936 : : }
937 : : EXPORT_SYMBOL_GPL(i2c_new_dummy);
938 : :
939 : : struct i2c_dummy_devres {
940 : : struct i2c_client *client;
941 : : };
942 : :
943 : 0 : static void devm_i2c_release_dummy(struct device *dev, void *res)
944 : : {
945 : : struct i2c_dummy_devres *this = res;
946 : :
947 : 0 : i2c_unregister_device(this->client);
948 : 0 : }
949 : :
950 : : /**
951 : : * devm_i2c_new_dummy_device - return a new i2c device bound to a dummy driver
952 : : * @dev: device the managed resource is bound to
953 : : * @adapter: the adapter managing the device
954 : : * @address: seven bit address to be used
955 : : * Context: can sleep
956 : : *
957 : : * This is the device-managed version of @i2c_new_dummy_device. It returns the
958 : : * new i2c client or an ERR_PTR in case of an error.
959 : : */
960 : 0 : struct i2c_client *devm_i2c_new_dummy_device(struct device *dev,
961 : : struct i2c_adapter *adapter,
962 : : u16 address)
963 : : {
964 : : struct i2c_dummy_devres *dr;
965 : : struct i2c_client *client;
966 : :
967 : : dr = devres_alloc(devm_i2c_release_dummy, sizeof(*dr), GFP_KERNEL);
968 [ # # ]: 0 : if (!dr)
969 : : return ERR_PTR(-ENOMEM);
970 : :
971 : 0 : client = i2c_new_dummy_device(adapter, address);
972 [ # # ]: 0 : if (IS_ERR(client)) {
973 : 0 : devres_free(dr);
974 : : } else {
975 : 0 : dr->client = client;
976 : 0 : devres_add(dev, dr);
977 : : }
978 : :
979 : 0 : return client;
980 : : }
981 : : EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device);
982 : :
983 : : /**
984 : : * i2c_new_ancillary_device - Helper to get the instantiated secondary address
985 : : * and create the associated device
986 : : * @client: Handle to the primary client
987 : : * @name: Handle to specify which secondary address to get
988 : : * @default_addr: Used as a fallback if no secondary address was specified
989 : : * Context: can sleep
990 : : *
991 : : * I2C clients can be composed of multiple I2C slaves bound together in a single
992 : : * component. The I2C client driver then binds to the master I2C slave and needs
993 : : * to create I2C dummy clients to communicate with all the other slaves.
994 : : *
995 : : * This function creates and returns an I2C dummy client whose I2C address is
996 : : * retrieved from the platform firmware based on the given slave name. If no
997 : : * address is specified by the firmware default_addr is used.
998 : : *
999 : : * On DT-based platforms the address is retrieved from the "reg" property entry
1000 : : * cell whose "reg-names" value matches the slave name.
1001 : : *
1002 : : * This returns the new i2c client, which should be saved for later use with
1003 : : * i2c_unregister_device(); or an ERR_PTR to describe the error.
1004 : : */
1005 : 0 : struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client,
1006 : : const char *name,
1007 : : u16 default_addr)
1008 : : {
1009 : 0 : struct device_node *np = client->dev.of_node;
1010 : 0 : u32 addr = default_addr;
1011 : : int i;
1012 : :
1013 [ # # ]: 0 : if (np) {
1014 : 0 : i = of_property_match_string(np, "reg-names", name);
1015 [ # # ]: 0 : if (i >= 0)
1016 : 0 : of_property_read_u32_index(np, "reg", i, &addr);
1017 : : }
1018 : :
1019 : : dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr);
1020 : 0 : return i2c_new_dummy_device(client->adapter, addr);
1021 : : }
1022 : : EXPORT_SYMBOL_GPL(i2c_new_ancillary_device);
1023 : :
1024 : : /* ------------------------------------------------------------------------- */
1025 : :
1026 : : /* I2C bus adapters -- one roots each I2C or SMBUS segment */
1027 : :
1028 : 0 : static void i2c_adapter_dev_release(struct device *dev)
1029 : : {
1030 : : struct i2c_adapter *adap = to_i2c_adapter(dev);
1031 : 0 : complete(&adap->dev_released);
1032 : 0 : }
1033 : :
1034 : 0 : unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
1035 : : {
1036 : : unsigned int depth = 0;
1037 : :
1038 [ # # ]: 0 : while ((adapter = i2c_parent_is_i2c_adapter(adapter)))
1039 : 0 : depth++;
1040 : :
1041 [ # # # # ]: 0 : WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES,
1042 : : "adapter depth exceeds lockdep subclass limit\n");
1043 : :
1044 : 0 : return depth;
1045 : : }
1046 : : EXPORT_SYMBOL_GPL(i2c_adapter_depth);
1047 : :
1048 : : /*
1049 : : * Let users instantiate I2C devices through sysfs. This can be used when
1050 : : * platform initialization code doesn't contain the proper data for
1051 : : * whatever reason. Also useful for drivers that do device detection and
1052 : : * detection fails, either because the device uses an unexpected address,
1053 : : * or this is a compatible device with different ID register values.
1054 : : *
1055 : : * Parameter checking may look overzealous, but we really don't want
1056 : : * the user to provide incorrect parameters.
1057 : : */
1058 : : static ssize_t
1059 : 0 : i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
1060 : : const char *buf, size_t count)
1061 : : {
1062 : 0 : struct i2c_adapter *adap = to_i2c_adapter(dev);
1063 : : struct i2c_board_info info;
1064 : : struct i2c_client *client;
1065 : : char *blank, end;
1066 : : int res;
1067 : :
1068 : 0 : memset(&info, 0, sizeof(struct i2c_board_info));
1069 : :
1070 : 0 : blank = strchr(buf, ' ');
1071 [ # # ]: 0 : if (!blank) {
1072 : 0 : dev_err(dev, "%s: Missing parameters\n", "new_device");
1073 : 0 : return -EINVAL;
1074 : : }
1075 [ # # ]: 0 : if (blank - buf > I2C_NAME_SIZE - 1) {
1076 : 0 : dev_err(dev, "%s: Invalid device name\n", "new_device");
1077 : 0 : return -EINVAL;
1078 : : }
1079 : 0 : memcpy(info.type, buf, blank - buf);
1080 : :
1081 : : /* Parse remaining parameters, reject extra parameters */
1082 : 0 : res = sscanf(++blank, "%hi%c", &info.addr, &end);
1083 [ # # ]: 0 : if (res < 1) {
1084 : 0 : dev_err(dev, "%s: Can't parse I2C address\n", "new_device");
1085 : 0 : return -EINVAL;
1086 : : }
1087 [ # # # # ]: 0 : if (res > 1 && end != '\n') {
1088 : 0 : dev_err(dev, "%s: Extra parameters\n", "new_device");
1089 : 0 : return -EINVAL;
1090 : : }
1091 : :
1092 [ # # ]: 0 : if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) {
1093 : 0 : info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT;
1094 : 0 : info.flags |= I2C_CLIENT_TEN;
1095 : : }
1096 : :
1097 [ # # ]: 0 : if (info.addr & I2C_ADDR_OFFSET_SLAVE) {
1098 : 0 : info.addr &= ~I2C_ADDR_OFFSET_SLAVE;
1099 : 0 : info.flags |= I2C_CLIENT_SLAVE;
1100 : : }
1101 : :
1102 : 0 : client = i2c_new_client_device(adap, &info);
1103 [ # # ]: 0 : if (IS_ERR(client))
1104 : 0 : return PTR_ERR(client);
1105 : :
1106 : : /* Keep track of the added device */
1107 : 0 : mutex_lock(&adap->userspace_clients_lock);
1108 : 0 : list_add_tail(&client->detected, &adap->userspace_clients);
1109 : 0 : mutex_unlock(&adap->userspace_clients_lock);
1110 : 0 : dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
1111 : : info.type, info.addr);
1112 : :
1113 : 0 : return count;
1114 : : }
1115 : : static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device);
1116 : :
1117 : : /*
1118 : : * And of course let the users delete the devices they instantiated, if
1119 : : * they got it wrong. This interface can only be used to delete devices
1120 : : * instantiated by i2c_sysfs_new_device above. This guarantees that we
1121 : : * don't delete devices to which some kernel code still has references.
1122 : : *
1123 : : * Parameter checking may look overzealous, but we really don't want
1124 : : * the user to delete the wrong device.
1125 : : */
1126 : : static ssize_t
1127 : 0 : i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
1128 : : const char *buf, size_t count)
1129 : : {
1130 : : struct i2c_adapter *adap = to_i2c_adapter(dev);
1131 : : struct i2c_client *client, *next;
1132 : : unsigned short addr;
1133 : : char end;
1134 : : int res;
1135 : :
1136 : : /* Parse parameters, reject extra parameters */
1137 : 0 : res = sscanf(buf, "%hi%c", &addr, &end);
1138 [ # # ]: 0 : if (res < 1) {
1139 : 0 : dev_err(dev, "%s: Can't parse I2C address\n", "delete_device");
1140 : 0 : return -EINVAL;
1141 : : }
1142 [ # # # # ]: 0 : if (res > 1 && end != '\n') {
1143 : 0 : dev_err(dev, "%s: Extra parameters\n", "delete_device");
1144 : 0 : return -EINVAL;
1145 : : }
1146 : :
1147 : : /* Make sure the device was added through sysfs */
1148 : : res = -ENOENT;
1149 : 0 : mutex_lock_nested(&adap->userspace_clients_lock,
1150 : : i2c_adapter_depth(adap));
1151 [ # # ]: 0 : list_for_each_entry_safe(client, next, &adap->userspace_clients,
1152 : : detected) {
1153 [ # # ]: 0 : if (i2c_encode_flags_to_addr(client) == addr) {
1154 : 0 : dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",
1155 : : "delete_device", client->name, client->addr);
1156 : :
1157 : : list_del(&client->detected);
1158 : 0 : i2c_unregister_device(client);
1159 : 0 : res = count;
1160 : 0 : break;
1161 : : }
1162 : : }
1163 : 0 : mutex_unlock(&adap->userspace_clients_lock);
1164 : :
1165 [ # # ]: 0 : if (res < 0)
1166 : 0 : dev_err(dev, "%s: Can't find device in list\n",
1167 : : "delete_device");
1168 : 0 : return res;
1169 : : }
1170 : : static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL,
1171 : : i2c_sysfs_delete_device);
1172 : :
1173 : : static struct attribute *i2c_adapter_attrs[] = {
1174 : : &dev_attr_name.attr,
1175 : : &dev_attr_new_device.attr,
1176 : : &dev_attr_delete_device.attr,
1177 : : NULL
1178 : : };
1179 : : ATTRIBUTE_GROUPS(i2c_adapter);
1180 : :
1181 : : struct device_type i2c_adapter_type = {
1182 : : .groups = i2c_adapter_groups,
1183 : : .release = i2c_adapter_dev_release,
1184 : : };
1185 : : EXPORT_SYMBOL_GPL(i2c_adapter_type);
1186 : :
1187 : : /**
1188 : : * i2c_verify_adapter - return parameter as i2c_adapter or NULL
1189 : : * @dev: device, probably from some driver model iterator
1190 : : *
1191 : : * When traversing the driver model tree, perhaps using driver model
1192 : : * iterators like @device_for_each_child(), you can't assume very much
1193 : : * about the nodes you find. Use this function to avoid oopses caused
1194 : : * by wrongly treating some non-I2C device as an i2c_adapter.
1195 : : */
1196 : 0 : struct i2c_adapter *i2c_verify_adapter(struct device *dev)
1197 : : {
1198 : 0 : return (dev->type == &i2c_adapter_type)
1199 : 0 : ? to_i2c_adapter(dev)
1200 [ # # ]: 0 : : NULL;
1201 : : }
1202 : : EXPORT_SYMBOL(i2c_verify_adapter);
1203 : :
1204 : : #ifdef CONFIG_I2C_COMPAT
1205 : : static struct class_compat *i2c_adapter_compat_class;
1206 : : #endif
1207 : :
1208 : 0 : static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
1209 : : {
1210 : : struct i2c_devinfo *devinfo;
1211 : :
1212 : 0 : down_read(&__i2c_board_lock);
1213 [ # # ]: 0 : list_for_each_entry(devinfo, &__i2c_board_list, list) {
1214 [ # # ]: 0 : if (devinfo->busnum == adapter->nr
1215 [ # # ]: 0 : && !i2c_new_device(adapter,
1216 : 0 : &devinfo->board_info))
1217 : 0 : dev_err(&adapter->dev,
1218 : : "Can't create device at 0x%02x\n",
1219 : : devinfo->board_info.addr);
1220 : : }
1221 : 0 : up_read(&__i2c_board_lock);
1222 : 0 : }
1223 : :
1224 : : static int i2c_do_add_adapter(struct i2c_driver *driver,
1225 : : struct i2c_adapter *adap)
1226 : : {
1227 : : /* Detect supported devices on that bus, and instantiate them */
1228 : 0 : i2c_detect(adap, driver);
1229 : :
1230 : : return 0;
1231 : : }
1232 : :
1233 : 0 : static int __process_new_adapter(struct device_driver *d, void *data)
1234 : : {
1235 : 0 : return i2c_do_add_adapter(to_i2c_driver(d), data);
1236 : : }
1237 : :
1238 : : static const struct i2c_lock_operations i2c_adapter_lock_ops = {
1239 : : .lock_bus = i2c_adapter_lock_bus,
1240 : : .trylock_bus = i2c_adapter_trylock_bus,
1241 : : .unlock_bus = i2c_adapter_unlock_bus,
1242 : : };
1243 : :
1244 : 0 : static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap)
1245 : : {
1246 : 0 : struct irq_domain *domain = adap->host_notify_domain;
1247 : : irq_hw_number_t hwirq;
1248 : :
1249 [ # # ]: 0 : if (!domain)
1250 : 0 : return;
1251 : :
1252 [ # # ]: 0 : for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++)
1253 : 0 : irq_dispose_mapping(irq_find_mapping(domain, hwirq));
1254 : :
1255 : 0 : irq_domain_remove(domain);
1256 : 0 : adap->host_notify_domain = NULL;
1257 : : }
1258 : :
1259 : 0 : static int i2c_host_notify_irq_map(struct irq_domain *h,
1260 : : unsigned int virq,
1261 : : irq_hw_number_t hw_irq_num)
1262 : : {
1263 : : irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
1264 : :
1265 : 0 : return 0;
1266 : : }
1267 : :
1268 : : static const struct irq_domain_ops i2c_host_notify_irq_ops = {
1269 : : .map = i2c_host_notify_irq_map,
1270 : : };
1271 : :
1272 : 0 : static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap)
1273 : : {
1274 : : struct irq_domain *domain;
1275 : :
1276 [ # # ]: 0 : if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY))
1277 : : return 0;
1278 : :
1279 : 0 : domain = irq_domain_create_linear(adap->dev.fwnode,
1280 : : I2C_ADDR_7BITS_COUNT,
1281 : : &i2c_host_notify_irq_ops, adap);
1282 [ # # ]: 0 : if (!domain)
1283 : : return -ENOMEM;
1284 : :
1285 : 0 : adap->host_notify_domain = domain;
1286 : :
1287 : 0 : return 0;
1288 : : }
1289 : :
1290 : : /**
1291 : : * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct
1292 : : * I2C client.
1293 : : * @adap: the adapter
1294 : : * @addr: the I2C address of the notifying device
1295 : : * Context: can't sleep
1296 : : *
1297 : : * Helper function to be called from an I2C bus driver's interrupt
1298 : : * handler. It will schedule the Host Notify IRQ.
1299 : : */
1300 : 0 : int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr)
1301 : : {
1302 : : int irq;
1303 : :
1304 [ # # ]: 0 : if (!adap)
1305 : : return -EINVAL;
1306 : :
1307 : 0 : irq = irq_find_mapping(adap->host_notify_domain, addr);
1308 [ # # ]: 0 : if (irq <= 0)
1309 : : return -ENXIO;
1310 : :
1311 : 0 : generic_handle_irq(irq);
1312 : :
1313 : 0 : return 0;
1314 : : }
1315 : : EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify);
1316 : :
1317 : 0 : static int i2c_register_adapter(struct i2c_adapter *adap)
1318 : : {
1319 : : int res = -EINVAL;
1320 : :
1321 : : /* Can't register until after driver model init */
1322 [ # # # # ]: 0 : if (WARN_ON(!is_registered)) {
1323 : : res = -EAGAIN;
1324 : : goto out_list;
1325 : : }
1326 : :
1327 : : /* Sanity checks */
1328 [ # # # # ]: 0 : if (WARN(!adap->name[0], "i2c adapter has no name"))
1329 : : goto out_list;
1330 : :
1331 [ # # ]: 0 : if (!adap->algo) {
1332 : 0 : pr_err("adapter '%s': no algo supplied!\n", adap->name);
1333 : 0 : goto out_list;
1334 : : }
1335 : :
1336 [ # # ]: 0 : if (!adap->lock_ops)
1337 : 0 : adap->lock_ops = &i2c_adapter_lock_ops;
1338 : :
1339 : 0 : adap->locked_flags = 0;
1340 : 0 : rt_mutex_init(&adap->bus_lock);
1341 : 0 : rt_mutex_init(&adap->mux_lock);
1342 : 0 : mutex_init(&adap->userspace_clients_lock);
1343 : 0 : INIT_LIST_HEAD(&adap->userspace_clients);
1344 : :
1345 : : /* Set default timeout to 1 second if not already set */
1346 [ # # ]: 0 : if (adap->timeout == 0)
1347 : 0 : adap->timeout = HZ;
1348 : :
1349 : : /* register soft irqs for Host Notify */
1350 : 0 : res = i2c_setup_host_notify_irq_domain(adap);
1351 [ # # ]: 0 : if (res) {
1352 : 0 : pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n",
1353 : : adap->name, res);
1354 : 0 : goto out_list;
1355 : : }
1356 : :
1357 : 0 : dev_set_name(&adap->dev, "i2c-%d", adap->nr);
1358 : 0 : adap->dev.bus = &i2c_bus_type;
1359 : 0 : adap->dev.type = &i2c_adapter_type;
1360 : 0 : res = device_register(&adap->dev);
1361 [ # # ]: 0 : if (res) {
1362 : 0 : pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
1363 : 0 : goto out_list;
1364 : : }
1365 : :
1366 : : res = of_i2c_setup_smbus_alert(adap);
1367 : : if (res)
1368 : : goto out_reg;
1369 : :
1370 : : dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
1371 : :
1372 : 0 : pm_runtime_no_callbacks(&adap->dev);
1373 : : pm_suspend_ignore_children(&adap->dev, true);
1374 : 0 : pm_runtime_enable(&adap->dev);
1375 : :
1376 : : #ifdef CONFIG_I2C_COMPAT
1377 : 0 : res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev,
1378 : : adap->dev.parent);
1379 [ # # ]: 0 : if (res)
1380 : 0 : dev_warn(&adap->dev,
1381 : : "Failed to create compatibility class link\n");
1382 : : #endif
1383 : :
1384 : 0 : i2c_init_recovery(adap);
1385 : :
1386 : : /* create pre-declared device nodes */
1387 : 0 : of_i2c_register_devices(adap);
1388 : : i2c_acpi_register_devices(adap);
1389 : : i2c_acpi_install_space_handler(adap);
1390 : :
1391 [ # # ]: 0 : if (adap->nr < __i2c_first_dynamic_bus_num)
1392 : 0 : i2c_scan_static_board_info(adap);
1393 : :
1394 : : /* Notify drivers */
1395 : 0 : mutex_lock(&core_lock);
1396 : 0 : bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter);
1397 : 0 : mutex_unlock(&core_lock);
1398 : :
1399 : 0 : return 0;
1400 : :
1401 : : out_reg:
1402 : : init_completion(&adap->dev_released);
1403 : : device_unregister(&adap->dev);
1404 : : wait_for_completion(&adap->dev_released);
1405 : : out_list:
1406 : 0 : mutex_lock(&core_lock);
1407 : 0 : idr_remove(&i2c_adapter_idr, adap->nr);
1408 : 0 : mutex_unlock(&core_lock);
1409 : 0 : return res;
1410 : : }
1411 : :
1412 : : /**
1413 : : * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1
1414 : : * @adap: the adapter to register (with adap->nr initialized)
1415 : : * Context: can sleep
1416 : : *
1417 : : * See i2c_add_numbered_adapter() for details.
1418 : : */
1419 : 0 : static int __i2c_add_numbered_adapter(struct i2c_adapter *adap)
1420 : : {
1421 : : int id;
1422 : :
1423 : 0 : mutex_lock(&core_lock);
1424 : 0 : id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL);
1425 : 0 : mutex_unlock(&core_lock);
1426 [ # # # # ]: 0 : if (WARN(id < 0, "couldn't get idr"))
1427 [ # # ]: 0 : return id == -ENOSPC ? -EBUSY : id;
1428 : :
1429 : 0 : return i2c_register_adapter(adap);
1430 : : }
1431 : :
1432 : : /**
1433 : : * i2c_add_adapter - declare i2c adapter, use dynamic bus number
1434 : : * @adapter: the adapter to add
1435 : : * Context: can sleep
1436 : : *
1437 : : * This routine is used to declare an I2C adapter when its bus number
1438 : : * doesn't matter or when its bus number is specified by an dt alias.
1439 : : * Examples of bases when the bus number doesn't matter: I2C adapters
1440 : : * dynamically added by USB links or PCI plugin cards.
1441 : : *
1442 : : * When this returns zero, a new bus number was allocated and stored
1443 : : * in adap->nr, and the specified adapter became available for clients.
1444 : : * Otherwise, a negative errno value is returned.
1445 : : */
1446 : 0 : int i2c_add_adapter(struct i2c_adapter *adapter)
1447 : : {
1448 : : struct device *dev = &adapter->dev;
1449 : : int id;
1450 : :
1451 [ # # ]: 0 : if (dev->of_node) {
1452 : 0 : id = of_alias_get_id(dev->of_node, "i2c");
1453 [ # # ]: 0 : if (id >= 0) {
1454 : 0 : adapter->nr = id;
1455 : 0 : return __i2c_add_numbered_adapter(adapter);
1456 : : }
1457 : : }
1458 : :
1459 : 0 : mutex_lock(&core_lock);
1460 : 0 : id = idr_alloc(&i2c_adapter_idr, adapter,
1461 : : __i2c_first_dynamic_bus_num, 0, GFP_KERNEL);
1462 : 0 : mutex_unlock(&core_lock);
1463 [ # # # # ]: 0 : if (WARN(id < 0, "couldn't get idr"))
1464 : : return id;
1465 : :
1466 : 0 : adapter->nr = id;
1467 : :
1468 : 0 : return i2c_register_adapter(adapter);
1469 : : }
1470 : : EXPORT_SYMBOL(i2c_add_adapter);
1471 : :
1472 : : /**
1473 : : * i2c_add_numbered_adapter - declare i2c adapter, use static bus number
1474 : : * @adap: the adapter to register (with adap->nr initialized)
1475 : : * Context: can sleep
1476 : : *
1477 : : * This routine is used to declare an I2C adapter when its bus number
1478 : : * matters. For example, use it for I2C adapters from system-on-chip CPUs,
1479 : : * or otherwise built in to the system's mainboard, and where i2c_board_info
1480 : : * is used to properly configure I2C devices.
1481 : : *
1482 : : * If the requested bus number is set to -1, then this function will behave
1483 : : * identically to i2c_add_adapter, and will dynamically assign a bus number.
1484 : : *
1485 : : * If no devices have pre-been declared for this bus, then be sure to
1486 : : * register the adapter before any dynamically allocated ones. Otherwise
1487 : : * the required bus ID may not be available.
1488 : : *
1489 : : * When this returns zero, the specified adapter became available for
1490 : : * clients using the bus number provided in adap->nr. Also, the table
1491 : : * of I2C devices pre-declared using i2c_register_board_info() is scanned,
1492 : : * and the appropriate driver model device nodes are created. Otherwise, a
1493 : : * negative errno value is returned.
1494 : : */
1495 : 0 : int i2c_add_numbered_adapter(struct i2c_adapter *adap)
1496 : : {
1497 [ # # ]: 0 : if (adap->nr == -1) /* -1 means dynamically assign bus id */
1498 : 0 : return i2c_add_adapter(adap);
1499 : :
1500 : 0 : return __i2c_add_numbered_adapter(adap);
1501 : : }
1502 : : EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
1503 : :
1504 : 0 : static void i2c_do_del_adapter(struct i2c_driver *driver,
1505 : : struct i2c_adapter *adapter)
1506 : : {
1507 : : struct i2c_client *client, *_n;
1508 : :
1509 : : /* Remove the devices we created ourselves as the result of hardware
1510 : : * probing (using a driver's detect method) */
1511 [ # # ]: 0 : list_for_each_entry_safe(client, _n, &driver->clients, detected) {
1512 [ # # ]: 0 : if (client->adapter == adapter) {
1513 : : dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",
1514 : : client->name, client->addr);
1515 : : list_del(&client->detected);
1516 : 0 : i2c_unregister_device(client);
1517 : : }
1518 : : }
1519 : 0 : }
1520 : :
1521 : 0 : static int __unregister_client(struct device *dev, void *dummy)
1522 : : {
1523 : : struct i2c_client *client = i2c_verify_client(dev);
1524 [ # # # # ]: 0 : if (client && strcmp(client->name, "dummy"))
1525 : 0 : i2c_unregister_device(client);
1526 : 0 : return 0;
1527 : : }
1528 : :
1529 : 0 : static int __unregister_dummy(struct device *dev, void *dummy)
1530 : : {
1531 : : struct i2c_client *client = i2c_verify_client(dev);
1532 : 0 : i2c_unregister_device(client);
1533 : 0 : return 0;
1534 : : }
1535 : :
1536 : 0 : static int __process_removed_adapter(struct device_driver *d, void *data)
1537 : : {
1538 : 0 : i2c_do_del_adapter(to_i2c_driver(d), data);
1539 : 0 : return 0;
1540 : : }
1541 : :
1542 : : /**
1543 : : * i2c_del_adapter - unregister I2C adapter
1544 : : * @adap: the adapter being unregistered
1545 : : * Context: can sleep
1546 : : *
1547 : : * This unregisters an I2C adapter which was previously registered
1548 : : * by @i2c_add_adapter or @i2c_add_numbered_adapter.
1549 : : */
1550 : 0 : void i2c_del_adapter(struct i2c_adapter *adap)
1551 : : {
1552 : : struct i2c_adapter *found;
1553 : : struct i2c_client *client, *next;
1554 : :
1555 : : /* First make sure that this adapter was ever added */
1556 : 0 : mutex_lock(&core_lock);
1557 : 0 : found = idr_find(&i2c_adapter_idr, adap->nr);
1558 : 0 : mutex_unlock(&core_lock);
1559 [ # # ]: 0 : if (found != adap) {
1560 : : pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name);
1561 : 0 : return;
1562 : : }
1563 : :
1564 : : i2c_acpi_remove_space_handler(adap);
1565 : : /* Tell drivers about this removal */
1566 : 0 : mutex_lock(&core_lock);
1567 : 0 : bus_for_each_drv(&i2c_bus_type, NULL, adap,
1568 : : __process_removed_adapter);
1569 : 0 : mutex_unlock(&core_lock);
1570 : :
1571 : : /* Remove devices instantiated from sysfs */
1572 : 0 : mutex_lock_nested(&adap->userspace_clients_lock,
1573 : : i2c_adapter_depth(adap));
1574 [ # # ]: 0 : list_for_each_entry_safe(client, next, &adap->userspace_clients,
1575 : : detected) {
1576 : : dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,
1577 : : client->addr);
1578 : : list_del(&client->detected);
1579 : 0 : i2c_unregister_device(client);
1580 : : }
1581 : 0 : mutex_unlock(&adap->userspace_clients_lock);
1582 : :
1583 : : /* Detach any active clients. This can't fail, thus we do not
1584 : : * check the returned value. This is a two-pass process, because
1585 : : * we can't remove the dummy devices during the first pass: they
1586 : : * could have been instantiated by real devices wishing to clean
1587 : : * them up properly, so we give them a chance to do that first. */
1588 : 0 : device_for_each_child(&adap->dev, NULL, __unregister_client);
1589 : 0 : device_for_each_child(&adap->dev, NULL, __unregister_dummy);
1590 : :
1591 : : #ifdef CONFIG_I2C_COMPAT
1592 : 0 : class_compat_remove_link(i2c_adapter_compat_class, &adap->dev,
1593 : : adap->dev.parent);
1594 : : #endif
1595 : :
1596 : : /* device name is gone after device_unregister */
1597 : : dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
1598 : :
1599 : : pm_runtime_disable(&adap->dev);
1600 : :
1601 : 0 : i2c_host_notify_irq_teardown(adap);
1602 : :
1603 : : /* wait until all references to the device are gone
1604 : : *
1605 : : * FIXME: This is old code and should ideally be replaced by an
1606 : : * alternative which results in decoupling the lifetime of the struct
1607 : : * device from the i2c_adapter, like spi or netdev do. Any solution
1608 : : * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled!
1609 : : */
1610 : : init_completion(&adap->dev_released);
1611 : 0 : device_unregister(&adap->dev);
1612 : 0 : wait_for_completion(&adap->dev_released);
1613 : :
1614 : : /* free bus id */
1615 : 0 : mutex_lock(&core_lock);
1616 : 0 : idr_remove(&i2c_adapter_idr, adap->nr);
1617 : 0 : mutex_unlock(&core_lock);
1618 : :
1619 : : /* Clear the device structure in case this adapter is ever going to be
1620 : : added again */
1621 : 0 : memset(&adap->dev, 0, sizeof(adap->dev));
1622 : : }
1623 : : EXPORT_SYMBOL(i2c_del_adapter);
1624 : :
1625 : : /**
1626 : : * i2c_parse_fw_timings - get I2C related timing parameters from firmware
1627 : : * @dev: The device to scan for I2C timing properties
1628 : : * @t: the i2c_timings struct to be filled with values
1629 : : * @use_defaults: bool to use sane defaults derived from the I2C specification
1630 : : * when properties are not found, otherwise use 0
1631 : : *
1632 : : * Scan the device for the generic I2C properties describing timing parameters
1633 : : * for the signal and fill the given struct with the results. If a property was
1634 : : * not found and use_defaults was true, then maximum timings are assumed which
1635 : : * are derived from the I2C specification. If use_defaults is not used, the
1636 : : * results will be 0, so drivers can apply their own defaults later. The latter
1637 : : * is mainly intended for avoiding regressions of existing drivers which want
1638 : : * to switch to this function. New drivers almost always should use the defaults.
1639 : : */
1640 : :
1641 : 0 : void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults)
1642 : : {
1643 : : int ret;
1644 : :
1645 : 0 : memset(t, 0, sizeof(*t));
1646 : :
1647 : 0 : ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz);
1648 [ # # ]: 0 : if (ret && use_defaults)
1649 : 0 : t->bus_freq_hz = 100000;
1650 : :
1651 : 0 : ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns);
1652 [ # # ]: 0 : if (ret && use_defaults) {
1653 [ # # ]: 0 : if (t->bus_freq_hz <= 100000)
1654 : 0 : t->scl_rise_ns = 1000;
1655 [ # # ]: 0 : else if (t->bus_freq_hz <= 400000)
1656 : 0 : t->scl_rise_ns = 300;
1657 : : else
1658 : 0 : t->scl_rise_ns = 120;
1659 : : }
1660 : :
1661 : 0 : ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns);
1662 [ # # ]: 0 : if (ret && use_defaults) {
1663 [ # # ]: 0 : if (t->bus_freq_hz <= 400000)
1664 : 0 : t->scl_fall_ns = 300;
1665 : : else
1666 : 0 : t->scl_fall_ns = 120;
1667 : : }
1668 : :
1669 : 0 : device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns);
1670 : :
1671 : 0 : ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns);
1672 [ # # ]: 0 : if (ret && use_defaults)
1673 : 0 : t->sda_fall_ns = t->scl_fall_ns;
1674 : :
1675 : 0 : device_property_read_u32(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns);
1676 : 0 : }
1677 : : EXPORT_SYMBOL_GPL(i2c_parse_fw_timings);
1678 : :
1679 : : /* ------------------------------------------------------------------------- */
1680 : :
1681 : 1212 : int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data))
1682 : : {
1683 : : int res;
1684 : :
1685 : 1212 : mutex_lock(&core_lock);
1686 : 1212 : res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn);
1687 : 1212 : mutex_unlock(&core_lock);
1688 : :
1689 : 1212 : return res;
1690 : : }
1691 : : EXPORT_SYMBOL_GPL(i2c_for_each_dev);
1692 : :
1693 : 0 : static int __process_new_driver(struct device *dev, void *data)
1694 : : {
1695 [ # # ]: 0 : if (dev->type != &i2c_adapter_type)
1696 : : return 0;
1697 : 0 : return i2c_do_add_adapter(data, to_i2c_adapter(dev));
1698 : : }
1699 : :
1700 : : /*
1701 : : * An i2c_driver is used with one or more i2c_client (device) nodes to access
1702 : : * i2c slave chips, on a bus instance associated with some i2c_adapter.
1703 : : */
1704 : :
1705 : 808 : int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
1706 : : {
1707 : : int res;
1708 : :
1709 : : /* Can't register until after driver model init */
1710 [ - + + - ]: 808 : if (WARN_ON(!is_registered))
1711 : : return -EAGAIN;
1712 : :
1713 : : /* add the driver to the list of i2c drivers in the driver core */
1714 : 808 : driver->driver.owner = owner;
1715 : 808 : driver->driver.bus = &i2c_bus_type;
1716 : 808 : INIT_LIST_HEAD(&driver->clients);
1717 : :
1718 : : /* When registration returns, the driver core
1719 : : * will have called probe() for all matching-but-unbound devices.
1720 : : */
1721 : 808 : res = driver_register(&driver->driver);
1722 [ + - ]: 808 : if (res)
1723 : : return res;
1724 : :
1725 : : pr_debug("driver [%s] registered\n", driver->driver.name);
1726 : :
1727 : : /* Walk the adapters that are already present */
1728 : 808 : i2c_for_each_dev(driver, __process_new_driver);
1729 : :
1730 : 808 : return 0;
1731 : : }
1732 : : EXPORT_SYMBOL(i2c_register_driver);
1733 : :
1734 : 0 : static int __process_removed_driver(struct device *dev, void *data)
1735 : : {
1736 [ # # ]: 0 : if (dev->type == &i2c_adapter_type)
1737 : 0 : i2c_do_del_adapter(data, to_i2c_adapter(dev));
1738 : 0 : return 0;
1739 : : }
1740 : :
1741 : : /**
1742 : : * i2c_del_driver - unregister I2C driver
1743 : : * @driver: the driver being unregistered
1744 : : * Context: can sleep
1745 : : */
1746 : 0 : void i2c_del_driver(struct i2c_driver *driver)
1747 : : {
1748 : 0 : i2c_for_each_dev(driver, __process_removed_driver);
1749 : :
1750 : 0 : driver_unregister(&driver->driver);
1751 : : pr_debug("driver [%s] unregistered\n", driver->driver.name);
1752 : 0 : }
1753 : : EXPORT_SYMBOL(i2c_del_driver);
1754 : :
1755 : : /* ------------------------------------------------------------------------- */
1756 : :
1757 : : /**
1758 : : * i2c_use_client - increments the reference count of the i2c client structure
1759 : : * @client: the client being referenced
1760 : : *
1761 : : * Each live reference to a client should be refcounted. The driver model does
1762 : : * that automatically as part of driver binding, so that most drivers don't
1763 : : * need to do this explicitly: they hold a reference until they're unbound
1764 : : * from the device.
1765 : : *
1766 : : * A pointer to the client with the incremented reference counter is returned.
1767 : : */
1768 : 0 : struct i2c_client *i2c_use_client(struct i2c_client *client)
1769 : : {
1770 [ # # # # ]: 0 : if (client && get_device(&client->dev))
1771 : 0 : return client;
1772 : : return NULL;
1773 : : }
1774 : : EXPORT_SYMBOL(i2c_use_client);
1775 : :
1776 : : /**
1777 : : * i2c_release_client - release a use of the i2c client structure
1778 : : * @client: the client being no longer referenced
1779 : : *
1780 : : * Must be called when a user of a client is finished with it.
1781 : : */
1782 : 0 : void i2c_release_client(struct i2c_client *client)
1783 : : {
1784 [ # # ]: 0 : if (client)
1785 : 0 : put_device(&client->dev);
1786 : 0 : }
1787 : : EXPORT_SYMBOL(i2c_release_client);
1788 : :
1789 : : struct i2c_cmd_arg {
1790 : : unsigned cmd;
1791 : : void *arg;
1792 : : };
1793 : :
1794 : 0 : static int i2c_cmd(struct device *dev, void *_arg)
1795 : : {
1796 : : struct i2c_client *client = i2c_verify_client(dev);
1797 : : struct i2c_cmd_arg *arg = _arg;
1798 : : struct i2c_driver *driver;
1799 : :
1800 [ # # # # ]: 0 : if (!client || !client->dev.driver)
1801 : : return 0;
1802 : :
1803 : : driver = to_i2c_driver(client->dev.driver);
1804 [ # # ]: 0 : if (driver->command)
1805 : 0 : driver->command(client, arg->cmd, arg->arg);
1806 : : return 0;
1807 : : }
1808 : :
1809 : 0 : void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
1810 : : {
1811 : : struct i2c_cmd_arg cmd_arg;
1812 : :
1813 : 0 : cmd_arg.cmd = cmd;
1814 : 0 : cmd_arg.arg = arg;
1815 : 0 : device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);
1816 : 0 : }
1817 : : EXPORT_SYMBOL(i2c_clients_command);
1818 : :
1819 : 404 : static int __init i2c_init(void)
1820 : : {
1821 : : int retval;
1822 : :
1823 : 404 : retval = of_alias_get_highest_id("i2c");
1824 : :
1825 : 404 : down_write(&__i2c_board_lock);
1826 [ + - ]: 404 : if (retval >= __i2c_first_dynamic_bus_num)
1827 : 404 : __i2c_first_dynamic_bus_num = retval + 1;
1828 : 404 : up_write(&__i2c_board_lock);
1829 : :
1830 : 404 : retval = bus_register(&i2c_bus_type);
1831 [ + - ]: 404 : if (retval)
1832 : : return retval;
1833 : :
1834 : 404 : is_registered = true;
1835 : :
1836 : : #ifdef CONFIG_I2C_COMPAT
1837 : 404 : i2c_adapter_compat_class = class_compat_register("i2c-adapter");
1838 [ + - ]: 404 : if (!i2c_adapter_compat_class) {
1839 : : retval = -ENOMEM;
1840 : : goto bus_err;
1841 : : }
1842 : : #endif
1843 : 404 : retval = i2c_add_driver(&dummy_driver);
1844 [ + - ]: 404 : if (retval)
1845 : : goto class_err;
1846 : :
1847 : : if (IS_ENABLED(CONFIG_OF_DYNAMIC))
1848 [ - + ]: 404 : WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier));
1849 : : if (IS_ENABLED(CONFIG_ACPI))
1850 : : WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier));
1851 : :
1852 : : return 0;
1853 : :
1854 : : class_err:
1855 : : #ifdef CONFIG_I2C_COMPAT
1856 : 0 : class_compat_unregister(i2c_adapter_compat_class);
1857 : : bus_err:
1858 : : #endif
1859 : 0 : is_registered = false;
1860 : 0 : bus_unregister(&i2c_bus_type);
1861 : 0 : return retval;
1862 : : }
1863 : :
1864 : 0 : static void __exit i2c_exit(void)
1865 : : {
1866 : : if (IS_ENABLED(CONFIG_ACPI))
1867 : : WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier));
1868 : : if (IS_ENABLED(CONFIG_OF_DYNAMIC))
1869 [ # # ]: 0 : WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier));
1870 : : i2c_del_driver(&dummy_driver);
1871 : : #ifdef CONFIG_I2C_COMPAT
1872 : 0 : class_compat_unregister(i2c_adapter_compat_class);
1873 : : #endif
1874 : 0 : bus_unregister(&i2c_bus_type);
1875 : : tracepoint_synchronize_unregister();
1876 : 0 : }
1877 : :
1878 : : /* We must initialize early, because some subsystems register i2c drivers
1879 : : * in subsys_initcall() code, but are linked (and initialized) before i2c.
1880 : : */
1881 : : postcore_initcall(i2c_init);
1882 : : module_exit(i2c_exit);
1883 : :
1884 : : /* ----------------------------------------------------
1885 : : * the functional interface to the i2c busses.
1886 : : * ----------------------------------------------------
1887 : : */
1888 : :
1889 : : /* Check if val is exceeding the quirk IFF quirk is non 0 */
1890 : : #define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk)))
1891 : :
1892 : 0 : static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg)
1893 : : {
1894 [ # # # # ]: 0 : dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n",
1895 : : err_msg, msg->addr, msg->len,
1896 : : msg->flags & I2C_M_RD ? "read" : "write");
1897 : 0 : return -EOPNOTSUPP;
1898 : : }
1899 : :
1900 : 0 : static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
1901 : : {
1902 : 0 : const struct i2c_adapter_quirks *q = adap->quirks;
1903 : 0 : int max_num = q->max_num_msgs, i;
1904 : : bool do_len_check = true;
1905 : :
1906 [ # # ]: 0 : if (q->flags & I2C_AQ_COMB) {
1907 : : max_num = 2;
1908 : :
1909 : : /* special checks for combined messages */
1910 [ # # ]: 0 : if (num == 2) {
1911 [ # # # # ]: 0 : if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD)
1912 : 0 : return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write");
1913 : :
1914 [ # # # # ]: 0 : if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD))
1915 : 0 : return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read");
1916 : :
1917 [ # # # # ]: 0 : if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr)
1918 : 0 : return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr");
1919 : :
1920 [ # # # # ]: 0 : if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len))
1921 : 0 : return i2c_quirk_error(adap, &msgs[0], "msg too long");
1922 : :
1923 [ # # # # ]: 0 : if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len))
1924 : 0 : return i2c_quirk_error(adap, &msgs[1], "msg too long");
1925 : :
1926 : : do_len_check = false;
1927 : : }
1928 : : }
1929 : :
1930 [ # # ]: 0 : if (i2c_quirk_exceeded(num, max_num))
1931 : 0 : return i2c_quirk_error(adap, &msgs[0], "too many messages");
1932 : :
1933 [ # # ]: 0 : for (i = 0; i < num; i++) {
1934 : 0 : u16 len = msgs[i].len;
1935 : :
1936 [ # # ]: 0 : if (msgs[i].flags & I2C_M_RD) {
1937 [ # # # # : 0 : if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len))
# # ]
1938 : 0 : return i2c_quirk_error(adap, &msgs[i], "msg too long");
1939 : :
1940 [ # # # # ]: 0 : if (q->flags & I2C_AQ_NO_ZERO_LEN_READ && len == 0)
1941 : 0 : return i2c_quirk_error(adap, &msgs[i], "no zero length");
1942 : : } else {
1943 [ # # # # : 0 : if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len))
# # ]
1944 : 0 : return i2c_quirk_error(adap, &msgs[i], "msg too long");
1945 : :
1946 [ # # # # ]: 0 : if (q->flags & I2C_AQ_NO_ZERO_LEN_WRITE && len == 0)
1947 : 0 : return i2c_quirk_error(adap, &msgs[i], "no zero length");
1948 : : }
1949 : : }
1950 : :
1951 : : return 0;
1952 : : }
1953 : :
1954 : : /**
1955 : : * __i2c_transfer - unlocked flavor of i2c_transfer
1956 : : * @adap: Handle to I2C bus
1957 : : * @msgs: One or more messages to execute before STOP is issued to
1958 : : * terminate the operation; each message begins with a START.
1959 : : * @num: Number of messages to be executed.
1960 : : *
1961 : : * Returns negative errno, else the number of messages executed.
1962 : : *
1963 : : * Adapter lock must be held when calling this function. No debug logging
1964 : : * takes place. adap->algo->master_xfer existence isn't checked.
1965 : : */
1966 : 0 : int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
1967 : : {
1968 : : unsigned long orig_jiffies;
1969 : : int ret, try;
1970 : :
1971 [ # # # # ]: 0 : if (WARN_ON(!msgs || num < 1))
1972 : : return -EINVAL;
1973 : :
1974 : 0 : ret = __i2c_check_suspended(adap);
1975 [ # # ]: 0 : if (ret)
1976 : : return ret;
1977 : :
1978 [ # # # # ]: 0 : if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))
1979 : : return -EOPNOTSUPP;
1980 : :
1981 : : /*
1982 : : * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets
1983 : : * enabled. This is an efficient way of keeping the for-loop from
1984 : : * being executed when not needed.
1985 : : */
1986 [ # # ]: 0 : if (static_branch_unlikely(&i2c_trace_msg_key)) {
1987 : : int i;
1988 [ # # ]: 0 : for (i = 0; i < num; i++)
1989 [ # # ]: 0 : if (msgs[i].flags & I2C_M_RD)
1990 : 0 : trace_i2c_read(adap, &msgs[i], i);
1991 : : else
1992 : 0 : trace_i2c_write(adap, &msgs[i], i);
1993 : : }
1994 : :
1995 : : /* Retry automatically on arbitration loss */
1996 : 0 : orig_jiffies = jiffies;
1997 [ # # ]: 0 : for (ret = 0, try = 0; try <= adap->retries; try++) {
1998 [ # # # # ]: 0 : if (i2c_in_atomic_xfer_mode() && adap->algo->master_xfer_atomic)
1999 : 0 : ret = adap->algo->master_xfer_atomic(adap, msgs, num);
2000 : : else
2001 : 0 : ret = adap->algo->master_xfer(adap, msgs, num);
2002 : :
2003 [ # # ]: 0 : if (ret != -EAGAIN)
2004 : : break;
2005 [ # # ]: 0 : if (time_after(jiffies, orig_jiffies + adap->timeout))
2006 : : break;
2007 : : }
2008 : :
2009 [ # # ]: 0 : if (static_branch_unlikely(&i2c_trace_msg_key)) {
2010 : : int i;
2011 [ # # ]: 0 : for (i = 0; i < ret; i++)
2012 [ # # ]: 0 : if (msgs[i].flags & I2C_M_RD)
2013 : 0 : trace_i2c_reply(adap, &msgs[i], i);
2014 : 0 : trace_i2c_result(adap, num, ret);
2015 : : }
2016 : :
2017 : 0 : return ret;
2018 : : }
2019 : : EXPORT_SYMBOL(__i2c_transfer);
2020 : :
2021 : : /**
2022 : : * i2c_transfer - execute a single or combined I2C message
2023 : : * @adap: Handle to I2C bus
2024 : : * @msgs: One or more messages to execute before STOP is issued to
2025 : : * terminate the operation; each message begins with a START.
2026 : : * @num: Number of messages to be executed.
2027 : : *
2028 : : * Returns negative errno, else the number of messages executed.
2029 : : *
2030 : : * Note that there is no requirement that each message be sent to
2031 : : * the same slave address, although that is the most common model.
2032 : : */
2033 : 0 : int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
2034 : : {
2035 : : int ret;
2036 : :
2037 [ # # ]: 0 : if (!adap->algo->master_xfer) {
2038 : : dev_dbg(&adap->dev, "I2C level transfers not supported\n");
2039 : : return -EOPNOTSUPP;
2040 : : }
2041 : :
2042 : : /* REVISIT the fault reporting model here is weak:
2043 : : *
2044 : : * - When we get an error after receiving N bytes from a slave,
2045 : : * there is no way to report "N".
2046 : : *
2047 : : * - When we get a NAK after transmitting N bytes to a slave,
2048 : : * there is no way to report "N" ... or to let the master
2049 : : * continue executing the rest of this combined message, if
2050 : : * that's the appropriate response.
2051 : : *
2052 : : * - When for example "num" is two and we successfully complete
2053 : : * the first message but get an error part way through the
2054 : : * second, it's unclear whether that should be reported as
2055 : : * one (discarding status on the second message) or errno
2056 : : * (discarding status on the first one).
2057 : : */
2058 : 0 : ret = __i2c_lock_bus_helper(adap);
2059 [ # # ]: 0 : if (ret)
2060 : : return ret;
2061 : :
2062 : 0 : ret = __i2c_transfer(adap, msgs, num);
2063 : : i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
2064 : :
2065 : 0 : return ret;
2066 : : }
2067 : : EXPORT_SYMBOL(i2c_transfer);
2068 : :
2069 : : /**
2070 : : * i2c_transfer_buffer_flags - issue a single I2C message transferring data
2071 : : * to/from a buffer
2072 : : * @client: Handle to slave device
2073 : : * @buf: Where the data is stored
2074 : : * @count: How many bytes to transfer, must be less than 64k since msg.len is u16
2075 : : * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads
2076 : : *
2077 : : * Returns negative errno, or else the number of bytes transferred.
2078 : : */
2079 : 0 : int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf,
2080 : : int count, u16 flags)
2081 : : {
2082 : : int ret;
2083 : 0 : struct i2c_msg msg = {
2084 : 0 : .addr = client->addr,
2085 : 0 : .flags = flags | (client->flags & I2C_M_TEN),
2086 : : .len = count,
2087 : : .buf = buf,
2088 : : };
2089 : :
2090 : 0 : ret = i2c_transfer(client->adapter, &msg, 1);
2091 : :
2092 : : /*
2093 : : * If everything went ok (i.e. 1 msg transferred), return #bytes
2094 : : * transferred, else error code.
2095 : : */
2096 [ # # ]: 0 : return (ret == 1) ? count : ret;
2097 : : }
2098 : : EXPORT_SYMBOL(i2c_transfer_buffer_flags);
2099 : :
2100 : : /**
2101 : : * i2c_get_device_id - get manufacturer, part id and die revision of a device
2102 : : * @client: The device to query
2103 : : * @id: The queried information
2104 : : *
2105 : : * Returns negative errno on error, zero on success.
2106 : : */
2107 : 0 : int i2c_get_device_id(const struct i2c_client *client,
2108 : : struct i2c_device_identity *id)
2109 : : {
2110 : 0 : struct i2c_adapter *adap = client->adapter;
2111 : : union i2c_smbus_data raw_id;
2112 : : int ret;
2113 : :
2114 [ # # ]: 0 : if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
2115 : : return -EOPNOTSUPP;
2116 : :
2117 : 0 : raw_id.block[0] = 3;
2118 : 0 : ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0,
2119 : 0 : I2C_SMBUS_READ, client->addr << 1,
2120 : : I2C_SMBUS_I2C_BLOCK_DATA, &raw_id);
2121 [ # # ]: 0 : if (ret)
2122 : : return ret;
2123 : :
2124 : 0 : id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4);
2125 : 0 : id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3);
2126 : 0 : id->die_revision = raw_id.block[3] & 0x7;
2127 : 0 : return 0;
2128 : : }
2129 : : EXPORT_SYMBOL_GPL(i2c_get_device_id);
2130 : :
2131 : : /* ----------------------------------------------------
2132 : : * the i2c address scanning function
2133 : : * Will not work for 10-bit addresses!
2134 : : * ----------------------------------------------------
2135 : : */
2136 : :
2137 : : /*
2138 : : * Legacy default probe function, mostly relevant for SMBus. The default
2139 : : * probe method is a quick write, but it is known to corrupt the 24RF08
2140 : : * EEPROMs due to a state machine bug, and could also irreversibly
2141 : : * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f,
2142 : : * we use a short byte read instead. Also, some bus drivers don't implement
2143 : : * quick write, so we fallback to a byte read in that case too.
2144 : : * On x86, there is another special case for FSC hardware monitoring chips,
2145 : : * which want regular byte reads (address 0x73.) Fortunately, these are the
2146 : : * only known chips using this I2C address on PC hardware.
2147 : : * Returns 1 if probe succeeded, 0 if not.
2148 : : */
2149 : 0 : static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr)
2150 : : {
2151 : : int err;
2152 : : union i2c_smbus_data dummy;
2153 : :
2154 : : #ifdef CONFIG_X86
2155 : : if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON)
2156 : : && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA))
2157 : : err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
2158 : : I2C_SMBUS_BYTE_DATA, &dummy);
2159 : : else
2160 : : #endif
2161 [ # # # # ]: 0 : if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50)
2162 [ # # ]: 0 : && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK))
2163 : 0 : err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0,
2164 : : I2C_SMBUS_QUICK, NULL);
2165 [ # # ]: 0 : else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE))
2166 : 0 : err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
2167 : : I2C_SMBUS_BYTE, &dummy);
2168 : : else {
2169 : 0 : dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n",
2170 : : addr);
2171 : : err = -EOPNOTSUPP;
2172 : : }
2173 : :
2174 : 0 : return err >= 0;
2175 : : }
2176 : :
2177 : 0 : static int i2c_detect_address(struct i2c_client *temp_client,
2178 : : struct i2c_driver *driver)
2179 : : {
2180 : : struct i2c_board_info info;
2181 : 0 : struct i2c_adapter *adapter = temp_client->adapter;
2182 : 0 : int addr = temp_client->addr;
2183 : : int err;
2184 : :
2185 : : /* Make sure the address is valid */
2186 : : err = i2c_check_7bit_addr_validity_strict(addr);
2187 [ # # ]: 0 : if (err) {
2188 : 0 : dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
2189 : : addr);
2190 : 0 : return err;
2191 : : }
2192 : :
2193 : : /* Skip if already in use (7 bit, no need to encode flags) */
2194 [ # # ]: 0 : if (i2c_check_addr_busy(adapter, addr))
2195 : : return 0;
2196 : :
2197 : : /* Make sure there is something at this address */
2198 [ # # ]: 0 : if (!i2c_default_probe(adapter, addr))
2199 : : return 0;
2200 : :
2201 : : /* Finally call the custom detection function */
2202 : 0 : memset(&info, 0, sizeof(struct i2c_board_info));
2203 : 0 : info.addr = addr;
2204 : 0 : err = driver->detect(temp_client, &info);
2205 [ # # ]: 0 : if (err) {
2206 : : /* -ENODEV is returned if the detection fails. We catch it
2207 : : here as this isn't an error. */
2208 [ # # ]: 0 : return err == -ENODEV ? 0 : err;
2209 : : }
2210 : :
2211 : : /* Consistency check */
2212 [ # # ]: 0 : if (info.type[0] == '\0') {
2213 : 0 : dev_err(&adapter->dev,
2214 : : "%s detection function provided no name for 0x%x\n",
2215 : : driver->driver.name, addr);
2216 : : } else {
2217 : : struct i2c_client *client;
2218 : :
2219 : : /* Detection succeeded, instantiate the device */
2220 [ # # ]: 0 : if (adapter->class & I2C_CLASS_DEPRECATED)
2221 : 0 : dev_warn(&adapter->dev,
2222 : : "This adapter will soon drop class based instantiation of devices. "
2223 : : "Please make sure client 0x%02x gets instantiated by other means. "
2224 : : "Check 'Documentation/i2c/instantiating-devices.rst' for details.\n",
2225 : : info.addr);
2226 : :
2227 : : dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
2228 : : info.type, info.addr);
2229 : : client = i2c_new_device(adapter, &info);
2230 [ # # ]: 0 : if (client)
2231 : 0 : list_add_tail(&client->detected, &driver->clients);
2232 : : else
2233 : 0 : dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n",
2234 : : info.type, info.addr);
2235 : : }
2236 : : return 0;
2237 : : }
2238 : :
2239 : 0 : static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
2240 : : {
2241 : : const unsigned short *address_list;
2242 : : struct i2c_client *temp_client;
2243 : : int i, err = 0;
2244 : : int adap_id = i2c_adapter_id(adapter);
2245 : :
2246 : 0 : address_list = driver->address_list;
2247 [ # # # # ]: 0 : if (!driver->detect || !address_list)
2248 : : return 0;
2249 : :
2250 : : /* Warn that the adapter lost class based instantiation */
2251 [ # # ]: 0 : if (adapter->class == I2C_CLASS_DEPRECATED) {
2252 : : dev_dbg(&adapter->dev,
2253 : : "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. "
2254 : : "If you need it, check 'Documentation/i2c/instantiating-devices.rst' for alternatives.\n",
2255 : : driver->driver.name);
2256 : : return 0;
2257 : : }
2258 : :
2259 : : /* Stop here if the classes do not match */
2260 [ # # ]: 0 : if (!(adapter->class & driver->class))
2261 : : return 0;
2262 : :
2263 : : /* Set up a temporary client to help detect callback */
2264 : 0 : temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
2265 [ # # ]: 0 : if (!temp_client)
2266 : : return -ENOMEM;
2267 : 0 : temp_client->adapter = adapter;
2268 : :
2269 [ # # ]: 0 : for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {
2270 : : dev_dbg(&adapter->dev,
2271 : : "found normal entry for adapter %d, addr 0x%02x\n",
2272 : : adap_id, address_list[i]);
2273 : 0 : temp_client->addr = address_list[i];
2274 : 0 : err = i2c_detect_address(temp_client, driver);
2275 [ # # ]: 0 : if (unlikely(err))
2276 : : break;
2277 : : }
2278 : :
2279 : 0 : kfree(temp_client);
2280 : 0 : return err;
2281 : : }
2282 : :
2283 : 0 : int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr)
2284 : : {
2285 : 0 : return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
2286 : 0 : I2C_SMBUS_QUICK, NULL) >= 0;
2287 : : }
2288 : : EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read);
2289 : :
2290 : : struct i2c_client *
2291 : 0 : i2c_new_probed_device(struct i2c_adapter *adap,
2292 : : struct i2c_board_info *info,
2293 : : unsigned short const *addr_list,
2294 : : int (*probe)(struct i2c_adapter *adap, unsigned short addr))
2295 : : {
2296 : : int i;
2297 : :
2298 [ # # ]: 0 : if (!probe)
2299 : : probe = i2c_default_probe;
2300 : :
2301 [ # # ]: 0 : for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
2302 : : /* Check address validity */
2303 [ # # ]: 0 : if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) {
2304 : 0 : dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n",
2305 : : addr_list[i]);
2306 : 0 : continue;
2307 : : }
2308 : :
2309 : : /* Check address availability (7 bit, no need to encode flags) */
2310 [ # # ]: 0 : if (i2c_check_addr_busy(adap, addr_list[i])) {
2311 : : dev_dbg(&adap->dev,
2312 : : "Address 0x%02x already in use, not probing\n",
2313 : : addr_list[i]);
2314 : 0 : continue;
2315 : : }
2316 : :
2317 : : /* Test address responsiveness */
2318 [ # # ]: 0 : if (probe(adap, addr_list[i]))
2319 : : break;
2320 : : }
2321 : :
2322 [ # # ]: 0 : if (addr_list[i] == I2C_CLIENT_END) {
2323 : : dev_dbg(&adap->dev, "Probing failed, no device found\n");
2324 : : return NULL;
2325 : : }
2326 : :
2327 : 0 : info->addr = addr_list[i];
2328 : 0 : return i2c_new_device(adap, info);
2329 : : }
2330 : : EXPORT_SYMBOL_GPL(i2c_new_probed_device);
2331 : :
2332 : 0 : struct i2c_adapter *i2c_get_adapter(int nr)
2333 : : {
2334 : : struct i2c_adapter *adapter;
2335 : :
2336 : 0 : mutex_lock(&core_lock);
2337 : 0 : adapter = idr_find(&i2c_adapter_idr, nr);
2338 [ # # ]: 0 : if (!adapter)
2339 : : goto exit;
2340 : :
2341 [ # # ]: 0 : if (try_module_get(adapter->owner))
2342 : 0 : get_device(&adapter->dev);
2343 : : else
2344 : : adapter = NULL;
2345 : :
2346 : : exit:
2347 : 0 : mutex_unlock(&core_lock);
2348 : 0 : return adapter;
2349 : : }
2350 : : EXPORT_SYMBOL(i2c_get_adapter);
2351 : :
2352 : 0 : void i2c_put_adapter(struct i2c_adapter *adap)
2353 : : {
2354 [ # # ]: 0 : if (!adap)
2355 : 0 : return;
2356 : :
2357 : 0 : put_device(&adap->dev);
2358 : 0 : module_put(adap->owner);
2359 : : }
2360 : : EXPORT_SYMBOL(i2c_put_adapter);
2361 : :
2362 : : /**
2363 : : * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg
2364 : : * @msg: the message to be checked
2365 : : * @threshold: the minimum number of bytes for which using DMA makes sense.
2366 : : * Should at least be 1.
2367 : : *
2368 : : * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO.
2369 : : * Or a valid pointer to be used with DMA. After use, release it by
2370 : : * calling i2c_put_dma_safe_msg_buf().
2371 : : *
2372 : : * This function must only be called from process context!
2373 : : */
2374 : 0 : u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold)
2375 : : {
2376 : : /* also skip 0-length msgs for bogus thresholds of 0 */
2377 : : if (!threshold)
2378 : : pr_debug("DMA buffer for addr=0x%02x with length 0 is bogus\n",
2379 : : msg->addr);
2380 [ # # # # ]: 0 : if (msg->len < threshold || msg->len == 0)
2381 : : return NULL;
2382 : :
2383 [ # # ]: 0 : if (msg->flags & I2C_M_DMA_SAFE)
2384 : 0 : return msg->buf;
2385 : :
2386 : : pr_debug("using bounce buffer for addr=0x%02x, len=%d\n",
2387 : : msg->addr, msg->len);
2388 : :
2389 [ # # ]: 0 : if (msg->flags & I2C_M_RD)
2390 : 0 : return kzalloc(msg->len, GFP_KERNEL);
2391 : : else
2392 : 0 : return kmemdup(msg->buf, msg->len, GFP_KERNEL);
2393 : : }
2394 : : EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf);
2395 : :
2396 : : /**
2397 : : * i2c_put_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg
2398 : : * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL.
2399 : : * @msg: the message which the buffer corresponds to
2400 : : * @xferred: bool saying if the message was transferred
2401 : : */
2402 : 0 : void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred)
2403 : : {
2404 [ # # # # ]: 0 : if (!buf || buf == msg->buf)
2405 : 0 : return;
2406 : :
2407 [ # # # # ]: 0 : if (xferred && msg->flags & I2C_M_RD)
2408 : 0 : memcpy(msg->buf, buf, msg->len);
2409 : :
2410 : 0 : kfree(buf);
2411 : : }
2412 : : EXPORT_SYMBOL_GPL(i2c_put_dma_safe_msg_buf);
2413 : :
2414 : : MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
2415 : : MODULE_DESCRIPTION("I2C-Bus main module");
2416 : : MODULE_LICENSE("GPL");
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