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 : 0 : struct i2c_client *client = i2c_verify_client(dev);
96 : 0 : 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 [ # # ]: 0 : if (acpi_driver_match_device(dev, drv))
105 : : return 1;
106 : :
107 : 0 : driver = to_i2c_driver(drv);
108 : :
109 : : /* Finally an I2C match */
110 [ # # ]: 0 : if (i2c_match_id(driver->id_table, client))
111 : 0 : return 1;
112 : :
113 : : return 0;
114 : : }
115 : :
116 : 0 : static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
117 : : {
118 : 0 : struct i2c_client *client = to_i2c_client(dev);
119 : 0 : int rc;
120 : :
121 : 0 : rc = of_device_uevent_modalias(dev, env);
122 : 0 : if (rc != -ENODEV)
123 : : return rc;
124 : :
125 : 0 : rc = acpi_device_uevent_modalias(dev, env);
126 [ # # ]: 0 : 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 : : static void set_sda_gpio_value(struct i2c_adapter *adap, int val)
149 : : {
150 : : gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val);
151 : : }
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 : 0 : 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 : 0 : 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 : 0 : 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 : 0 : 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 : 0 : 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 : 0 : 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 : 0 : char *err_str;
258 : :
259 [ # # ]: 0 : if (!bri)
260 : : return;
261 : :
262 [ # # ]: 0 : if (!bri->recover_bus) {
263 : 0 : err_str = "no recover_bus() found";
264 : 0 : 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 : : bri->set_sda = set_sda_gpio_value;
275 : : }
276 : 0 : 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 : 0 : err_str = "no {get|set}_scl() found";
283 : 0 : goto err;
284 : : }
285 [ # # # # ]: 0 : if (!bri->set_sda && !bri->get_sda) {
286 : 0 : err_str = "either get_sda() or set_sda() needed";
287 : 0 : goto err;
288 : : }
289 : : }
290 : :
291 : : return;
292 : 0 : 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 : 0 : 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 : 0 : struct i2c_client *client = i2c_verify_client(dev);
316 : 0 : struct i2c_driver *driver;
317 : 0 : 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 : 0 : int irq = -ENOENT;
328 : :
329 [ # # ]: 0 : if (client->flags & I2C_CLIENT_HOST_NOTIFY) {
330 : 0 : 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 : : irq = of_irq_get_byname(dev->of_node, "irq");
336 : : if (irq == -EINVAL || irq == -ENODATA)
337 : : irq = of_irq_get(dev->of_node, 0);
338 [ # # # # ]: 0 : } else if (ACPI_COMPANION(dev)) {
339 : 0 : irq = i2c_acpi_get_irq(client);
340 : : }
341 [ # # ]: 0 : if (irq == -EPROBE_DEFER)
342 : : return irq;
343 : :
344 : 0 : if (irq < 0)
345 : : irq = 0;
346 : :
347 : 0 : client->irq = irq;
348 : : }
349 : :
350 : : /*
351 : : * An I2C ID table is not mandatory, if and only if, a suitable OF
352 : : * or ACPI ID table is supplied for the probing device.
353 : : */
354 [ # # # # ]: 0 : if (!driver->id_table &&
355 : 0 : !i2c_acpi_match_device(dev->driver->acpi_match_table, client) &&
356 : : !i2c_of_match_device(dev->driver->of_match_table, client))
357 : : return -ENODEV;
358 : :
359 [ # # ]: 0 : if (client->flags & I2C_CLIENT_WAKE) {
360 : 0 : int wakeirq;
361 : :
362 : 0 : wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
363 : 0 : if (wakeirq == -EPROBE_DEFER)
364 : : return wakeirq;
365 : :
366 : 0 : device_init_wakeup(&client->dev, true);
367 : :
368 : 0 : if (wakeirq > 0 && wakeirq != client->irq)
369 : : status = dev_pm_set_dedicated_wake_irq(dev, wakeirq);
370 [ # # ]: 0 : else if (client->irq > 0)
371 : 0 : status = dev_pm_set_wake_irq(dev, client->irq);
372 : : else
373 : : status = 0;
374 : :
375 [ # # ]: 0 : if (status)
376 : 0 : dev_warn(&client->dev, "failed to set up wakeup irq\n");
377 : : }
378 : :
379 : 0 : dev_dbg(dev, "probe\n");
380 : :
381 : 0 : status = of_clk_set_defaults(dev->of_node, false);
382 : 0 : if (status < 0)
383 : : goto err_clear_wakeup_irq;
384 : :
385 : 0 : status = dev_pm_domain_attach(&client->dev, true);
386 [ # # ]: 0 : if (status)
387 : 0 : goto err_clear_wakeup_irq;
388 : :
389 : : /*
390 : : * When there are no more users of probe(),
391 : : * rename probe_new to probe.
392 : : */
393 [ # # ]: 0 : if (driver->probe_new)
394 : 0 : status = driver->probe_new(client);
395 [ # # ]: 0 : else if (driver->probe)
396 : 0 : status = driver->probe(client,
397 : : i2c_match_id(driver->id_table, client));
398 : : else
399 : : status = -EINVAL;
400 : :
401 [ # # ]: 0 : if (status)
402 : 0 : goto err_detach_pm_domain;
403 : :
404 : : return 0;
405 : :
406 : : err_detach_pm_domain:
407 : 0 : dev_pm_domain_detach(&client->dev, true);
408 : 0 : err_clear_wakeup_irq:
409 : 0 : dev_pm_clear_wake_irq(&client->dev);
410 : 0 : device_init_wakeup(&client->dev, false);
411 : 0 : return status;
412 : : }
413 : :
414 : 0 : static int i2c_device_remove(struct device *dev)
415 : : {
416 : 0 : struct i2c_client *client = i2c_verify_client(dev);
417 : 0 : struct i2c_driver *driver;
418 : 0 : int status = 0;
419 : :
420 [ # # ]: 0 : if (!client || !dev->driver)
421 : : return 0;
422 : :
423 : 0 : driver = to_i2c_driver(dev->driver);
424 [ # # ]: 0 : if (driver->remove) {
425 : 0 : dev_dbg(dev, "remove\n");
426 : 0 : status = driver->remove(client);
427 : : }
428 : :
429 : 0 : dev_pm_domain_detach(&client->dev, true);
430 : :
431 : 0 : dev_pm_clear_wake_irq(&client->dev);
432 : 0 : device_init_wakeup(&client->dev, false);
433 : :
434 : 0 : client->irq = 0;
435 [ # # ]: 0 : if (client->flags & I2C_CLIENT_HOST_NOTIFY)
436 : 0 : pm_runtime_put(&client->adapter->dev);
437 : :
438 : : return status;
439 : : }
440 : :
441 : 0 : static void i2c_device_shutdown(struct device *dev)
442 : : {
443 : 0 : struct i2c_client *client = i2c_verify_client(dev);
444 : 0 : struct i2c_driver *driver;
445 : :
446 [ # # ]: 0 : if (!client || !dev->driver)
447 : : return;
448 : 0 : driver = to_i2c_driver(dev->driver);
449 [ # # ]: 0 : if (driver->shutdown)
450 : 0 : driver->shutdown(client);
451 : : }
452 : :
453 : 0 : static void i2c_client_dev_release(struct device *dev)
454 : : {
455 : 0 : kfree(to_i2c_client(dev));
456 : 0 : }
457 : :
458 : : static ssize_t
459 : 0 : name_show(struct device *dev, struct device_attribute *attr, char *buf)
460 : : {
461 [ # # ]: 0 : return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?
462 : 0 : to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);
463 : : }
464 : : static DEVICE_ATTR_RO(name);
465 : :
466 : : static ssize_t
467 : 0 : modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
468 : : {
469 : 0 : struct i2c_client *client = to_i2c_client(dev);
470 : 0 : int len;
471 : :
472 : 0 : len = of_device_modalias(dev, buf, PAGE_SIZE);
473 : 0 : if (len != -ENODEV)
474 : : return len;
475 : :
476 : 0 : len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
477 [ # # ]: 0 : if (len != -ENODEV)
478 : 0 : return len;
479 : :
480 : 0 : return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
481 : : }
482 : : static DEVICE_ATTR_RO(modalias);
483 : :
484 : : static struct attribute *i2c_dev_attrs[] = {
485 : : &dev_attr_name.attr,
486 : : /* modalias helps coldplug: modprobe $(cat .../modalias) */
487 : : &dev_attr_modalias.attr,
488 : : NULL
489 : : };
490 : : ATTRIBUTE_GROUPS(i2c_dev);
491 : :
492 : : struct bus_type i2c_bus_type = {
493 : : .name = "i2c",
494 : : .match = i2c_device_match,
495 : : .probe = i2c_device_probe,
496 : : .remove = i2c_device_remove,
497 : : .shutdown = i2c_device_shutdown,
498 : : };
499 : : EXPORT_SYMBOL_GPL(i2c_bus_type);
500 : :
501 : : struct device_type i2c_client_type = {
502 : : .groups = i2c_dev_groups,
503 : : .uevent = i2c_device_uevent,
504 : : .release = i2c_client_dev_release,
505 : : };
506 : : EXPORT_SYMBOL_GPL(i2c_client_type);
507 : :
508 : :
509 : : /**
510 : : * i2c_verify_client - return parameter as i2c_client, or NULL
511 : : * @dev: device, probably from some driver model iterator
512 : : *
513 : : * When traversing the driver model tree, perhaps using driver model
514 : : * iterators like @device_for_each_child(), you can't assume very much
515 : : * about the nodes you find. Use this function to avoid oopses caused
516 : : * by wrongly treating some non-I2C device as an i2c_client.
517 : : */
518 : 0 : struct i2c_client *i2c_verify_client(struct device *dev)
519 : : {
520 : 0 : return (dev->type == &i2c_client_type)
521 [ # # # # : 0 : ? to_i2c_client(dev)
# # ]
522 [ # # # # : 0 : : NULL;
# # # # #
# ]
523 : : }
524 : : EXPORT_SYMBOL(i2c_verify_client);
525 : :
526 : :
527 : : /* Return a unique address which takes the flags of the client into account */
528 : 0 : static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client)
529 : : {
530 : 0 : unsigned short addr = client->addr;
531 : :
532 : : /* For some client flags, add an arbitrary offset to avoid collisions */
533 : 0 : if (client->flags & I2C_CLIENT_TEN)
534 : 0 : addr |= I2C_ADDR_OFFSET_TEN_BIT;
535 : :
536 [ # # # # : 0 : if (client->flags & I2C_CLIENT_SLAVE)
# # # # ]
537 : 0 : addr |= I2C_ADDR_OFFSET_SLAVE;
538 : :
539 : 0 : return addr;
540 : : }
541 : :
542 : : /* This is a permissive address validity check, I2C address map constraints
543 : : * are purposely not enforced, except for the general call address. */
544 : 0 : static int i2c_check_addr_validity(unsigned int addr, unsigned short flags)
545 : : {
546 : 0 : if (flags & I2C_CLIENT_TEN) {
547 : : /* 10-bit address, all values are valid */
548 [ # # ]: 0 : if (addr > 0x3ff)
549 : : return -EINVAL;
550 : : } else {
551 : : /* 7-bit address, reject the general call address */
552 [ # # ]: 0 : if (addr == 0x00 || addr > 0x7f)
553 : : return -EINVAL;
554 : : }
555 : : return 0;
556 : : }
557 : :
558 : : /* And this is a strict address validity check, used when probing. If a
559 : : * device uses a reserved address, then it shouldn't be probed. 7-bit
560 : : * addressing is assumed, 10-bit address devices are rare and should be
561 : : * explicitly enumerated. */
562 : 0 : int i2c_check_7bit_addr_validity_strict(unsigned short addr)
563 : : {
564 : : /*
565 : : * Reserved addresses per I2C specification:
566 : : * 0x00 General call address / START byte
567 : : * 0x01 CBUS address
568 : : * 0x02 Reserved for different bus format
569 : : * 0x03 Reserved for future purposes
570 : : * 0x04-0x07 Hs-mode master code
571 : : * 0x78-0x7b 10-bit slave addressing
572 : : * 0x7c-0x7f Reserved for future purposes
573 : : */
574 [ # # ]: 0 : if (addr < 0x08 || addr > 0x77)
575 : 0 : return -EINVAL;
576 : : return 0;
577 : : }
578 : :
579 : 0 : static int __i2c_check_addr_busy(struct device *dev, void *addrp)
580 : : {
581 : 0 : struct i2c_client *client = i2c_verify_client(dev);
582 : 0 : int addr = *(int *)addrp;
583 : :
584 [ # # # # : 0 : if (client && i2c_encode_flags_to_addr(client) == addr)
# # ]
585 : 0 : return -EBUSY;
586 : : return 0;
587 : : }
588 : :
589 : : /* walk up mux tree */
590 : : static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)
591 : : {
592 : : struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
593 : : int result;
594 : :
595 : : result = device_for_each_child(&adapter->dev, &addr,
596 : : __i2c_check_addr_busy);
597 : :
598 : : if (!result && parent)
599 : : result = i2c_check_mux_parents(parent, addr);
600 : :
601 : : return result;
602 : : }
603 : :
604 : : /* recurse down mux tree */
605 : 0 : static int i2c_check_mux_children(struct device *dev, void *addrp)
606 : : {
607 : 0 : int result;
608 : :
609 [ # # ]: 0 : if (dev->type == &i2c_adapter_type)
610 : 0 : result = device_for_each_child(dev, addrp,
611 : : i2c_check_mux_children);
612 : : else
613 [ # # ]: 0 : result = __i2c_check_addr_busy(dev, addrp);
614 : :
615 : 0 : return result;
616 : : }
617 : :
618 : 0 : static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
619 : : {
620 : 0 : struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
621 : 0 : int result = 0;
622 : :
623 : 0 : if (parent)
624 : : result = i2c_check_mux_parents(parent, addr);
625 : :
626 : 0 : if (!result)
627 : 0 : result = device_for_each_child(&adapter->dev, &addr,
628 : : i2c_check_mux_children);
629 : :
630 : 0 : return result;
631 : : }
632 : :
633 : : /**
634 : : * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment
635 : : * @adapter: Target I2C bus segment
636 : : * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
637 : : * locks only this branch in the adapter tree
638 : : */
639 : 0 : static void i2c_adapter_lock_bus(struct i2c_adapter *adapter,
640 : : unsigned int flags)
641 : : {
642 : 0 : rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter));
643 : 0 : }
644 : :
645 : : /**
646 : : * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment
647 : : * @adapter: Target I2C bus segment
648 : : * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT
649 : : * trylocks only this branch in the adapter tree
650 : : */
651 : 0 : static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter,
652 : : unsigned int flags)
653 : : {
654 : 0 : return rt_mutex_trylock(&adapter->bus_lock);
655 : : }
656 : :
657 : : /**
658 : : * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment
659 : : * @adapter: Target I2C bus segment
660 : : * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
661 : : * unlocks only this branch in the adapter tree
662 : : */
663 : 0 : static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter,
664 : : unsigned int flags)
665 : : {
666 : 0 : rt_mutex_unlock(&adapter->bus_lock);
667 : 0 : }
668 : :
669 : 0 : static void i2c_dev_set_name(struct i2c_adapter *adap,
670 : : struct i2c_client *client,
671 : : struct i2c_board_info const *info)
672 : : {
673 [ # # ]: 0 : struct acpi_device *adev = ACPI_COMPANION(&client->dev);
674 : :
675 [ # # # # ]: 0 : if (info && info->dev_name) {
676 : 0 : dev_set_name(&client->dev, "i2c-%s", info->dev_name);
677 : 0 : return;
678 : : }
679 : :
680 [ # # ]: 0 : if (adev) {
681 [ # # ]: 0 : dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev));
682 : 0 : return;
683 : : }
684 : :
685 : 0 : dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
686 [ # # ]: 0 : i2c_encode_flags_to_addr(client));
687 : : }
688 : :
689 : 0 : int i2c_dev_irq_from_resources(const struct resource *resources,
690 : : unsigned int num_resources)
691 : : {
692 : 0 : struct irq_data *irqd;
693 : 0 : int i;
694 : :
695 [ # # ]: 0 : for (i = 0; i < num_resources; i++) {
696 : 0 : const struct resource *r = &resources[i];
697 : :
698 [ # # ]: 0 : if (resource_type(r) != IORESOURCE_IRQ)
699 : 0 : continue;
700 : :
701 [ # # ]: 0 : if (r->flags & IORESOURCE_BITS) {
702 : 0 : irqd = irq_get_irq_data(r->start);
703 [ # # ]: 0 : if (!irqd)
704 : : break;
705 : :
706 : 0 : irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
707 : : }
708 : :
709 : 0 : return r->start;
710 : : }
711 : :
712 : : return 0;
713 : : }
714 : :
715 : : /**
716 : : * i2c_new_client_device - instantiate an i2c device
717 : : * @adap: the adapter managing the device
718 : : * @info: describes one I2C device; bus_num is ignored
719 : : * Context: can sleep
720 : : *
721 : : * Create an i2c device. Binding is handled through driver model
722 : : * probe()/remove() methods. A driver may be bound to this device when we
723 : : * return from this function, or any later moment (e.g. maybe hotplugging will
724 : : * load the driver module). This call is not appropriate for use by mainboard
725 : : * initialization logic, which usually runs during an arch_initcall() long
726 : : * before any i2c_adapter could exist.
727 : : *
728 : : * This returns the new i2c client, which may be saved for later use with
729 : : * i2c_unregister_device(); or an ERR_PTR to describe the error.
730 : : */
731 : : struct i2c_client *
732 : 0 : i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
733 : : {
734 : 0 : struct i2c_client *client;
735 : 0 : int status;
736 : :
737 : 0 : client = kzalloc(sizeof *client, GFP_KERNEL);
738 [ # # ]: 0 : if (!client)
739 : : return ERR_PTR(-ENOMEM);
740 : :
741 : 0 : client->adapter = adap;
742 : :
743 : 0 : client->dev.platform_data = info->platform_data;
744 : 0 : client->flags = info->flags;
745 : 0 : client->addr = info->addr;
746 : :
747 : 0 : client->init_irq = info->irq;
748 [ # # ]: 0 : if (!client->init_irq)
749 : 0 : client->init_irq = i2c_dev_irq_from_resources(info->resources,
750 : : info->num_resources);
751 : :
752 : 0 : strlcpy(client->name, info->type, sizeof(client->name));
753 : :
754 [ # # ]: 0 : status = i2c_check_addr_validity(client->addr, client->flags);
755 : : if (status) {
756 [ # # ]: 0 : dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n",
757 : : client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr);
758 : 0 : goto out_err_silent;
759 : : }
760 : :
761 : : /* Check for address business */
762 [ # # ]: 0 : status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client));
763 [ # # ]: 0 : if (status)
764 : 0 : goto out_err;
765 : :
766 : 0 : client->dev.parent = &client->adapter->dev;
767 : 0 : client->dev.bus = &i2c_bus_type;
768 : 0 : client->dev.type = &i2c_client_type;
769 : 0 : client->dev.of_node = of_node_get(info->of_node);
770 : 0 : client->dev.fwnode = info->fwnode;
771 : :
772 : 0 : i2c_dev_set_name(adap, client, info);
773 : :
774 [ # # ]: 0 : if (info->properties) {
775 : 0 : status = device_add_properties(&client->dev, info->properties);
776 [ # # ]: 0 : if (status) {
777 : 0 : dev_err(&adap->dev,
778 : : "Failed to add properties to client %s: %d\n",
779 : : client->name, status);
780 : 0 : goto out_err_put_of_node;
781 : : }
782 : : }
783 : :
784 : 0 : status = device_register(&client->dev);
785 [ # # ]: 0 : if (status)
786 : 0 : goto out_free_props;
787 : :
788 : : dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
789 : : client->name, dev_name(&client->dev));
790 : :
791 : : return client;
792 : :
793 : : out_free_props:
794 [ # # ]: 0 : if (info->properties)
795 : 0 : device_remove_properties(&client->dev);
796 : 0 : out_err_put_of_node:
797 : 0 : of_node_put(info->of_node);
798 : 0 : out_err:
799 : 0 : dev_err(&adap->dev,
800 : : "Failed to register i2c client %s at 0x%02x (%d)\n",
801 : : client->name, client->addr, status);
802 : 0 : out_err_silent:
803 : 0 : kfree(client);
804 : 0 : return ERR_PTR(status);
805 : : }
806 : : EXPORT_SYMBOL_GPL(i2c_new_client_device);
807 : :
808 : : /**
809 : : * i2c_new_device - instantiate an i2c device
810 : : * @adap: the adapter managing the device
811 : : * @info: describes one I2C device; bus_num is ignored
812 : : * Context: can sleep
813 : : *
814 : : * This deprecated function has the same functionality as
815 : : * @i2c_new_client_device, it just returns NULL instead of an ERR_PTR in case of
816 : : * an error for compatibility with current I2C API. It will be removed once all
817 : : * users are converted.
818 : : *
819 : : * This returns the new i2c client, which may be saved for later use with
820 : : * i2c_unregister_device(); or NULL to indicate an error.
821 : : */
822 : : struct i2c_client *
823 : 0 : i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
824 : : {
825 : 0 : struct i2c_client *ret;
826 : :
827 : 0 : ret = i2c_new_client_device(adap, info);
828 [ # # ]: 0 : return IS_ERR(ret) ? NULL : ret;
829 : : }
830 : : EXPORT_SYMBOL_GPL(i2c_new_device);
831 : :
832 : :
833 : : /**
834 : : * i2c_unregister_device - reverse effect of i2c_new_*_device()
835 : : * @client: value returned from i2c_new_*_device()
836 : : * Context: can sleep
837 : : */
838 : 0 : void i2c_unregister_device(struct i2c_client *client)
839 : : {
840 [ # # # # ]: 0 : if (IS_ERR_OR_NULL(client))
841 : : return;
842 : :
843 : 0 : if (client->dev.of_node) {
844 : : of_node_clear_flag(client->dev.of_node, OF_POPULATED);
845 : : of_node_put(client->dev.of_node);
846 : : }
847 : :
848 [ # # # # ]: 0 : if (ACPI_COMPANION(&client->dev))
849 [ # # ]: 0 : acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev));
850 : 0 : device_unregister(&client->dev);
851 : : }
852 : : EXPORT_SYMBOL_GPL(i2c_unregister_device);
853 : :
854 : :
855 : : static const struct i2c_device_id dummy_id[] = {
856 : : { "dummy", 0 },
857 : : { },
858 : : };
859 : :
860 : 0 : static int dummy_probe(struct i2c_client *client,
861 : : const struct i2c_device_id *id)
862 : : {
863 : 0 : return 0;
864 : : }
865 : :
866 : 0 : static int dummy_remove(struct i2c_client *client)
867 : : {
868 : 0 : return 0;
869 : : }
870 : :
871 : : static struct i2c_driver dummy_driver = {
872 : : .driver.name = "dummy",
873 : : .probe = dummy_probe,
874 : : .remove = dummy_remove,
875 : : .id_table = dummy_id,
876 : : };
877 : :
878 : : /**
879 : : * i2c_new_dummy_device - return a new i2c device bound to a dummy driver
880 : : * @adapter: the adapter managing the device
881 : : * @address: seven bit address to be used
882 : : * Context: can sleep
883 : : *
884 : : * This returns an I2C client bound to the "dummy" driver, intended for use
885 : : * with devices that consume multiple addresses. Examples of such chips
886 : : * include various EEPROMS (like 24c04 and 24c08 models).
887 : : *
888 : : * These dummy devices have two main uses. First, most I2C and SMBus calls
889 : : * except i2c_transfer() need a client handle; the dummy will be that handle.
890 : : * And second, this prevents the specified address from being bound to a
891 : : * different driver.
892 : : *
893 : : * This returns the new i2c client, which should be saved for later use with
894 : : * i2c_unregister_device(); or an ERR_PTR to describe the error.
895 : : */
896 : 0 : struct i2c_client *i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address)
897 : : {
898 : 0 : struct i2c_board_info info = {
899 : : I2C_BOARD_INFO("dummy", address),
900 : : };
901 : :
902 : 0 : return i2c_new_client_device(adapter, &info);
903 : : }
904 : : EXPORT_SYMBOL_GPL(i2c_new_dummy_device);
905 : :
906 : : struct i2c_dummy_devres {
907 : : struct i2c_client *client;
908 : : };
909 : :
910 : 0 : static void devm_i2c_release_dummy(struct device *dev, void *res)
911 : : {
912 : 0 : struct i2c_dummy_devres *this = res;
913 : :
914 : 0 : i2c_unregister_device(this->client);
915 : 0 : }
916 : :
917 : : /**
918 : : * devm_i2c_new_dummy_device - return a new i2c device bound to a dummy driver
919 : : * @dev: device the managed resource is bound to
920 : : * @adapter: the adapter managing the device
921 : : * @address: seven bit address to be used
922 : : * Context: can sleep
923 : : *
924 : : * This is the device-managed version of @i2c_new_dummy_device. It returns the
925 : : * new i2c client or an ERR_PTR in case of an error.
926 : : */
927 : 0 : struct i2c_client *devm_i2c_new_dummy_device(struct device *dev,
928 : : struct i2c_adapter *adapter,
929 : : u16 address)
930 : : {
931 : 0 : struct i2c_dummy_devres *dr;
932 : 0 : struct i2c_client *client;
933 : :
934 : 0 : dr = devres_alloc(devm_i2c_release_dummy, sizeof(*dr), GFP_KERNEL);
935 [ # # ]: 0 : if (!dr)
936 : : return ERR_PTR(-ENOMEM);
937 : :
938 : 0 : client = i2c_new_dummy_device(adapter, address);
939 [ # # ]: 0 : if (IS_ERR(client)) {
940 : 0 : devres_free(dr);
941 : : } else {
942 : 0 : dr->client = client;
943 : 0 : devres_add(dev, dr);
944 : : }
945 : :
946 : : return client;
947 : : }
948 : : EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device);
949 : :
950 : : /**
951 : : * i2c_new_ancillary_device - Helper to get the instantiated secondary address
952 : : * and create the associated device
953 : : * @client: Handle to the primary client
954 : : * @name: Handle to specify which secondary address to get
955 : : * @default_addr: Used as a fallback if no secondary address was specified
956 : : * Context: can sleep
957 : : *
958 : : * I2C clients can be composed of multiple I2C slaves bound together in a single
959 : : * component. The I2C client driver then binds to the master I2C slave and needs
960 : : * to create I2C dummy clients to communicate with all the other slaves.
961 : : *
962 : : * This function creates and returns an I2C dummy client whose I2C address is
963 : : * retrieved from the platform firmware based on the given slave name. If no
964 : : * address is specified by the firmware default_addr is used.
965 : : *
966 : : * On DT-based platforms the address is retrieved from the "reg" property entry
967 : : * cell whose "reg-names" value matches the slave name.
968 : : *
969 : : * This returns the new i2c client, which should be saved for later use with
970 : : * i2c_unregister_device(); or an ERR_PTR to describe the error.
971 : : */
972 : 0 : struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client,
973 : : const char *name,
974 : : u16 default_addr)
975 : : {
976 : 0 : struct device_node *np = client->dev.of_node;
977 : 0 : u32 addr = default_addr;
978 : 0 : int i;
979 : :
980 : 0 : if (np) {
981 : : i = of_property_match_string(np, "reg-names", name);
982 : : if (i >= 0)
983 : : of_property_read_u32_index(np, "reg", i, &addr);
984 : : }
985 : :
986 : 0 : dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr);
987 : 0 : return i2c_new_dummy_device(client->adapter, addr);
988 : : }
989 : : EXPORT_SYMBOL_GPL(i2c_new_ancillary_device);
990 : :
991 : : /* ------------------------------------------------------------------------- */
992 : :
993 : : /* I2C bus adapters -- one roots each I2C or SMBUS segment */
994 : :
995 : 0 : static void i2c_adapter_dev_release(struct device *dev)
996 : : {
997 : 0 : struct i2c_adapter *adap = to_i2c_adapter(dev);
998 : 0 : complete(&adap->dev_released);
999 : 0 : }
1000 : :
1001 : 0 : unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
1002 : : {
1003 : 0 : unsigned int depth = 0;
1004 : :
1005 : 0 : while ((adapter = i2c_parent_is_i2c_adapter(adapter)))
1006 : : depth++;
1007 : :
1008 : 0 : WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES,
1009 : : "adapter depth exceeds lockdep subclass limit\n");
1010 : :
1011 : 0 : return depth;
1012 : : }
1013 : : EXPORT_SYMBOL_GPL(i2c_adapter_depth);
1014 : :
1015 : : /*
1016 : : * Let users instantiate I2C devices through sysfs. This can be used when
1017 : : * platform initialization code doesn't contain the proper data for
1018 : : * whatever reason. Also useful for drivers that do device detection and
1019 : : * detection fails, either because the device uses an unexpected address,
1020 : : * or this is a compatible device with different ID register values.
1021 : : *
1022 : : * Parameter checking may look overzealous, but we really don't want
1023 : : * the user to provide incorrect parameters.
1024 : : */
1025 : : static ssize_t
1026 : 0 : new_device_store(struct device *dev, struct device_attribute *attr,
1027 : : const char *buf, size_t count)
1028 : : {
1029 : 0 : struct i2c_adapter *adap = to_i2c_adapter(dev);
1030 : 0 : struct i2c_board_info info;
1031 : 0 : struct i2c_client *client;
1032 : 0 : char *blank, end;
1033 : 0 : int res;
1034 : :
1035 : 0 : memset(&info, 0, sizeof(struct i2c_board_info));
1036 : :
1037 : 0 : blank = strchr(buf, ' ');
1038 [ # # ]: 0 : if (!blank) {
1039 : 0 : dev_err(dev, "%s: Missing parameters\n", "new_device");
1040 : 0 : return -EINVAL;
1041 : : }
1042 [ # # ]: 0 : if (blank - buf > I2C_NAME_SIZE - 1) {
1043 : 0 : dev_err(dev, "%s: Invalid device name\n", "new_device");
1044 : 0 : return -EINVAL;
1045 : : }
1046 : 0 : memcpy(info.type, buf, blank - buf);
1047 : :
1048 : : /* Parse remaining parameters, reject extra parameters */
1049 : 0 : res = sscanf(++blank, "%hi%c", &info.addr, &end);
1050 [ # # ]: 0 : if (res < 1) {
1051 : 0 : dev_err(dev, "%s: Can't parse I2C address\n", "new_device");
1052 : 0 : return -EINVAL;
1053 : : }
1054 [ # # # # ]: 0 : if (res > 1 && end != '\n') {
1055 : 0 : dev_err(dev, "%s: Extra parameters\n", "new_device");
1056 : 0 : return -EINVAL;
1057 : : }
1058 : :
1059 [ # # ]: 0 : if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) {
1060 : 0 : info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT;
1061 : 0 : info.flags |= I2C_CLIENT_TEN;
1062 : : }
1063 : :
1064 [ # # ]: 0 : if (info.addr & I2C_ADDR_OFFSET_SLAVE) {
1065 : 0 : info.addr &= ~I2C_ADDR_OFFSET_SLAVE;
1066 : 0 : info.flags |= I2C_CLIENT_SLAVE;
1067 : : }
1068 : :
1069 : 0 : client = i2c_new_client_device(adap, &info);
1070 [ # # ]: 0 : if (IS_ERR(client))
1071 : 0 : return PTR_ERR(client);
1072 : :
1073 : : /* Keep track of the added device */
1074 : 0 : mutex_lock(&adap->userspace_clients_lock);
1075 : 0 : list_add_tail(&client->detected, &adap->userspace_clients);
1076 : 0 : mutex_unlock(&adap->userspace_clients_lock);
1077 : 0 : dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
1078 : : info.type, info.addr);
1079 : :
1080 : 0 : return count;
1081 : : }
1082 : : static DEVICE_ATTR_WO(new_device);
1083 : :
1084 : : /*
1085 : : * And of course let the users delete the devices they instantiated, if
1086 : : * they got it wrong. This interface can only be used to delete devices
1087 : : * instantiated by i2c_sysfs_new_device above. This guarantees that we
1088 : : * don't delete devices to which some kernel code still has references.
1089 : : *
1090 : : * Parameter checking may look overzealous, but we really don't want
1091 : : * the user to delete the wrong device.
1092 : : */
1093 : : static ssize_t
1094 : 0 : delete_device_store(struct device *dev, struct device_attribute *attr,
1095 : : const char *buf, size_t count)
1096 : : {
1097 : 0 : struct i2c_adapter *adap = to_i2c_adapter(dev);
1098 : 0 : struct i2c_client *client, *next;
1099 : 0 : unsigned short addr;
1100 : 0 : char end;
1101 : 0 : int res;
1102 : :
1103 : : /* Parse parameters, reject extra parameters */
1104 : 0 : res = sscanf(buf, "%hi%c", &addr, &end);
1105 [ # # ]: 0 : if (res < 1) {
1106 : 0 : dev_err(dev, "%s: Can't parse I2C address\n", "delete_device");
1107 : 0 : return -EINVAL;
1108 : : }
1109 [ # # # # ]: 0 : if (res > 1 && end != '\n') {
1110 : 0 : dev_err(dev, "%s: Extra parameters\n", "delete_device");
1111 : 0 : return -EINVAL;
1112 : : }
1113 : :
1114 : : /* Make sure the device was added through sysfs */
1115 : 0 : res = -ENOENT;
1116 : 0 : mutex_lock_nested(&adap->userspace_clients_lock,
1117 : : i2c_adapter_depth(adap));
1118 [ # # ]: 0 : list_for_each_entry_safe(client, next, &adap->userspace_clients,
1119 : : detected) {
1120 [ # # # # ]: 0 : if (i2c_encode_flags_to_addr(client) == addr) {
1121 : 0 : dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",
1122 : : "delete_device", client->name, client->addr);
1123 : :
1124 : 0 : list_del(&client->detected);
1125 : 0 : i2c_unregister_device(client);
1126 : 0 : res = count;
1127 : 0 : break;
1128 : : }
1129 : : }
1130 : 0 : mutex_unlock(&adap->userspace_clients_lock);
1131 : :
1132 [ # # ]: 0 : if (res < 0)
1133 : 0 : dev_err(dev, "%s: Can't find device in list\n",
1134 : : "delete_device");
1135 : 0 : return res;
1136 : : }
1137 : : static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL,
1138 : : delete_device_store);
1139 : :
1140 : : static struct attribute *i2c_adapter_attrs[] = {
1141 : : &dev_attr_name.attr,
1142 : : &dev_attr_new_device.attr,
1143 : : &dev_attr_delete_device.attr,
1144 : : NULL
1145 : : };
1146 : : ATTRIBUTE_GROUPS(i2c_adapter);
1147 : :
1148 : : struct device_type i2c_adapter_type = {
1149 : : .groups = i2c_adapter_groups,
1150 : : .release = i2c_adapter_dev_release,
1151 : : };
1152 : : EXPORT_SYMBOL_GPL(i2c_adapter_type);
1153 : :
1154 : : /**
1155 : : * i2c_verify_adapter - return parameter as i2c_adapter or NULL
1156 : : * @dev: device, probably from some driver model iterator
1157 : : *
1158 : : * When traversing the driver model tree, perhaps using driver model
1159 : : * iterators like @device_for_each_child(), you can't assume very much
1160 : : * about the nodes you find. Use this function to avoid oopses caused
1161 : : * by wrongly treating some non-I2C device as an i2c_adapter.
1162 : : */
1163 : 0 : struct i2c_adapter *i2c_verify_adapter(struct device *dev)
1164 : : {
1165 : 0 : return (dev->type == &i2c_adapter_type)
1166 : 0 : ? to_i2c_adapter(dev)
1167 [ # # ]: 0 : : NULL;
1168 : : }
1169 : : EXPORT_SYMBOL(i2c_verify_adapter);
1170 : :
1171 : : #ifdef CONFIG_I2C_COMPAT
1172 : : static struct class_compat *i2c_adapter_compat_class;
1173 : : #endif
1174 : :
1175 : 0 : static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
1176 : : {
1177 : 0 : struct i2c_devinfo *devinfo;
1178 : :
1179 : 0 : down_read(&__i2c_board_lock);
1180 [ # # ]: 0 : list_for_each_entry(devinfo, &__i2c_board_list, list) {
1181 [ # # # # ]: 0 : if (devinfo->busnum == adapter->nr &&
1182 : 0 : IS_ERR(i2c_new_client_device(adapter, &devinfo->board_info)))
1183 : 0 : dev_err(&adapter->dev,
1184 : : "Can't create device at 0x%02x\n",
1185 : : devinfo->board_info.addr);
1186 : : }
1187 : 0 : up_read(&__i2c_board_lock);
1188 : 0 : }
1189 : :
1190 : 0 : static int i2c_do_add_adapter(struct i2c_driver *driver,
1191 : : struct i2c_adapter *adap)
1192 : : {
1193 : : /* Detect supported devices on that bus, and instantiate them */
1194 : 0 : i2c_detect(adap, driver);
1195 : :
1196 : 0 : return 0;
1197 : : }
1198 : :
1199 : 0 : static int __process_new_adapter(struct device_driver *d, void *data)
1200 : : {
1201 : 0 : return i2c_do_add_adapter(to_i2c_driver(d), data);
1202 : : }
1203 : :
1204 : : static const struct i2c_lock_operations i2c_adapter_lock_ops = {
1205 : : .lock_bus = i2c_adapter_lock_bus,
1206 : : .trylock_bus = i2c_adapter_trylock_bus,
1207 : : .unlock_bus = i2c_adapter_unlock_bus,
1208 : : };
1209 : :
1210 : : static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap)
1211 : : {
1212 : : struct irq_domain *domain = adap->host_notify_domain;
1213 : : irq_hw_number_t hwirq;
1214 : :
1215 : : if (!domain)
1216 : : return;
1217 : :
1218 : : for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++)
1219 : : irq_dispose_mapping(irq_find_mapping(domain, hwirq));
1220 : :
1221 : : irq_domain_remove(domain);
1222 : : adap->host_notify_domain = NULL;
1223 : : }
1224 : :
1225 : 0 : static int i2c_host_notify_irq_map(struct irq_domain *h,
1226 : : unsigned int virq,
1227 : : irq_hw_number_t hw_irq_num)
1228 : : {
1229 : 0 : irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
1230 : :
1231 : 0 : return 0;
1232 : : }
1233 : :
1234 : : static const struct irq_domain_ops i2c_host_notify_irq_ops = {
1235 : : .map = i2c_host_notify_irq_map,
1236 : : };
1237 : :
1238 : 0 : static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap)
1239 : : {
1240 : 0 : struct irq_domain *domain;
1241 : :
1242 [ # # ]: 0 : if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY))
1243 : : return 0;
1244 : :
1245 : 0 : domain = irq_domain_create_linear(adap->dev.fwnode,
1246 : : I2C_ADDR_7BITS_COUNT,
1247 : : &i2c_host_notify_irq_ops, adap);
1248 [ # # ]: 0 : if (!domain)
1249 : : return -ENOMEM;
1250 : :
1251 : 0 : adap->host_notify_domain = domain;
1252 : :
1253 : 0 : return 0;
1254 : : }
1255 : :
1256 : : /**
1257 : : * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct
1258 : : * I2C client.
1259 : : * @adap: the adapter
1260 : : * @addr: the I2C address of the notifying device
1261 : : * Context: can't sleep
1262 : : *
1263 : : * Helper function to be called from an I2C bus driver's interrupt
1264 : : * handler. It will schedule the Host Notify IRQ.
1265 : : */
1266 : 0 : int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr)
1267 : : {
1268 : 0 : int irq;
1269 : :
1270 [ # # ]: 0 : if (!adap)
1271 : : return -EINVAL;
1272 : :
1273 : 0 : irq = irq_find_mapping(adap->host_notify_domain, addr);
1274 [ # # ]: 0 : if (irq <= 0)
1275 : : return -ENXIO;
1276 : :
1277 : 0 : generic_handle_irq(irq);
1278 : :
1279 : 0 : return 0;
1280 : : }
1281 : : EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify);
1282 : :
1283 : 0 : static int i2c_register_adapter(struct i2c_adapter *adap)
1284 : : {
1285 : 0 : int res = -EINVAL;
1286 : :
1287 : : /* Can't register until after driver model init */
1288 [ # # # # ]: 0 : if (WARN_ON(!is_registered)) {
1289 : 0 : res = -EAGAIN;
1290 : 0 : goto out_list;
1291 : : }
1292 : :
1293 : : /* Sanity checks */
1294 [ # # # # ]: 0 : if (WARN(!adap->name[0], "i2c adapter has no name"))
1295 : 0 : goto out_list;
1296 : :
1297 [ # # ]: 0 : if (!adap->algo) {
1298 : 0 : pr_err("adapter '%s': no algo supplied!\n", adap->name);
1299 : 0 : goto out_list;
1300 : : }
1301 : :
1302 [ # # ]: 0 : if (!adap->lock_ops)
1303 : 0 : adap->lock_ops = &i2c_adapter_lock_ops;
1304 : :
1305 : 0 : adap->locked_flags = 0;
1306 : 0 : rt_mutex_init(&adap->bus_lock);
1307 : 0 : rt_mutex_init(&adap->mux_lock);
1308 : 0 : mutex_init(&adap->userspace_clients_lock);
1309 [ # # ]: 0 : INIT_LIST_HEAD(&adap->userspace_clients);
1310 : :
1311 : : /* Set default timeout to 1 second if not already set */
1312 [ # # ]: 0 : if (adap->timeout == 0)
1313 : 0 : adap->timeout = HZ;
1314 : :
1315 : : /* register soft irqs for Host Notify */
1316 : 0 : res = i2c_setup_host_notify_irq_domain(adap);
1317 [ # # ]: 0 : if (res) {
1318 : 0 : pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n",
1319 : : adap->name, res);
1320 : 0 : goto out_list;
1321 : : }
1322 : :
1323 : 0 : dev_set_name(&adap->dev, "i2c-%d", adap->nr);
1324 : 0 : adap->dev.bus = &i2c_bus_type;
1325 : 0 : adap->dev.type = &i2c_adapter_type;
1326 : 0 : res = device_register(&adap->dev);
1327 [ # # ]: 0 : if (res) {
1328 : 0 : pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
1329 : 0 : goto out_list;
1330 : : }
1331 : :
1332 : 0 : res = of_i2c_setup_smbus_alert(adap);
1333 : 0 : if (res)
1334 : : goto out_reg;
1335 : :
1336 : 0 : dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
1337 : :
1338 : 0 : pm_runtime_no_callbacks(&adap->dev);
1339 : 0 : pm_suspend_ignore_children(&adap->dev, true);
1340 : 0 : pm_runtime_enable(&adap->dev);
1341 : :
1342 : : #ifdef CONFIG_I2C_COMPAT
1343 : 0 : res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev,
1344 : : adap->dev.parent);
1345 [ # # ]: 0 : if (res)
1346 : 0 : dev_warn(&adap->dev,
1347 : : "Failed to create compatibility class link\n");
1348 : : #endif
1349 : :
1350 : 0 : i2c_init_recovery(adap);
1351 : :
1352 : : /* create pre-declared device nodes */
1353 : 0 : of_i2c_register_devices(adap);
1354 : 0 : i2c_acpi_register_devices(adap);
1355 : 0 : i2c_acpi_install_space_handler(adap);
1356 : :
1357 [ # # ]: 0 : if (adap->nr < __i2c_first_dynamic_bus_num)
1358 : 0 : i2c_scan_static_board_info(adap);
1359 : :
1360 : : /* Notify drivers */
1361 : 0 : mutex_lock(&core_lock);
1362 : 0 : bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter);
1363 : 0 : mutex_unlock(&core_lock);
1364 : :
1365 : 0 : return 0;
1366 : :
1367 : : out_reg:
1368 : : init_completion(&adap->dev_released);
1369 : : device_unregister(&adap->dev);
1370 : : wait_for_completion(&adap->dev_released);
1371 : 0 : out_list:
1372 : 0 : mutex_lock(&core_lock);
1373 : 0 : idr_remove(&i2c_adapter_idr, adap->nr);
1374 : 0 : mutex_unlock(&core_lock);
1375 : 0 : return res;
1376 : : }
1377 : :
1378 : : /**
1379 : : * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1
1380 : : * @adap: the adapter to register (with adap->nr initialized)
1381 : : * Context: can sleep
1382 : : *
1383 : : * See i2c_add_numbered_adapter() for details.
1384 : : */
1385 : 0 : static int __i2c_add_numbered_adapter(struct i2c_adapter *adap)
1386 : : {
1387 : 0 : int id;
1388 : :
1389 : 0 : mutex_lock(&core_lock);
1390 : 0 : id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL);
1391 : 0 : mutex_unlock(&core_lock);
1392 [ # # # # ]: 0 : if (WARN(id < 0, "couldn't get idr"))
1393 [ # # ]: 0 : return id == -ENOSPC ? -EBUSY : id;
1394 : :
1395 : 0 : return i2c_register_adapter(adap);
1396 : : }
1397 : :
1398 : : /**
1399 : : * i2c_add_adapter - declare i2c adapter, use dynamic bus number
1400 : : * @adapter: the adapter to add
1401 : : * Context: can sleep
1402 : : *
1403 : : * This routine is used to declare an I2C adapter when its bus number
1404 : : * doesn't matter or when its bus number is specified by an dt alias.
1405 : : * Examples of bases when the bus number doesn't matter: I2C adapters
1406 : : * dynamically added by USB links or PCI plugin cards.
1407 : : *
1408 : : * When this returns zero, a new bus number was allocated and stored
1409 : : * in adap->nr, and the specified adapter became available for clients.
1410 : : * Otherwise, a negative errno value is returned.
1411 : : */
1412 : 0 : int i2c_add_adapter(struct i2c_adapter *adapter)
1413 : : {
1414 : 0 : struct device *dev = &adapter->dev;
1415 : 0 : int id;
1416 : :
1417 : 0 : if (dev->of_node) {
1418 : : id = of_alias_get_id(dev->of_node, "i2c");
1419 : : if (id >= 0) {
1420 : : adapter->nr = id;
1421 : : return __i2c_add_numbered_adapter(adapter);
1422 : : }
1423 : : }
1424 : :
1425 : 0 : mutex_lock(&core_lock);
1426 : 0 : id = idr_alloc(&i2c_adapter_idr, adapter,
1427 : : __i2c_first_dynamic_bus_num, 0, GFP_KERNEL);
1428 : 0 : mutex_unlock(&core_lock);
1429 [ # # # # ]: 0 : if (WARN(id < 0, "couldn't get idr"))
1430 : : return id;
1431 : :
1432 : 0 : adapter->nr = id;
1433 : :
1434 : 0 : return i2c_register_adapter(adapter);
1435 : : }
1436 : : EXPORT_SYMBOL(i2c_add_adapter);
1437 : :
1438 : : /**
1439 : : * i2c_add_numbered_adapter - declare i2c adapter, use static bus number
1440 : : * @adap: the adapter to register (with adap->nr initialized)
1441 : : * Context: can sleep
1442 : : *
1443 : : * This routine is used to declare an I2C adapter when its bus number
1444 : : * matters. For example, use it for I2C adapters from system-on-chip CPUs,
1445 : : * or otherwise built in to the system's mainboard, and where i2c_board_info
1446 : : * is used to properly configure I2C devices.
1447 : : *
1448 : : * If the requested bus number is set to -1, then this function will behave
1449 : : * identically to i2c_add_adapter, and will dynamically assign a bus number.
1450 : : *
1451 : : * If no devices have pre-been declared for this bus, then be sure to
1452 : : * register the adapter before any dynamically allocated ones. Otherwise
1453 : : * the required bus ID may not be available.
1454 : : *
1455 : : * When this returns zero, the specified adapter became available for
1456 : : * clients using the bus number provided in adap->nr. Also, the table
1457 : : * of I2C devices pre-declared using i2c_register_board_info() is scanned,
1458 : : * and the appropriate driver model device nodes are created. Otherwise, a
1459 : : * negative errno value is returned.
1460 : : */
1461 : 0 : int i2c_add_numbered_adapter(struct i2c_adapter *adap)
1462 : : {
1463 [ # # ]: 0 : if (adap->nr == -1) /* -1 means dynamically assign bus id */
1464 : 0 : return i2c_add_adapter(adap);
1465 : :
1466 : 0 : return __i2c_add_numbered_adapter(adap);
1467 : : }
1468 : : EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
1469 : :
1470 : 0 : static void i2c_do_del_adapter(struct i2c_driver *driver,
1471 : : struct i2c_adapter *adapter)
1472 : : {
1473 : 0 : struct i2c_client *client, *_n;
1474 : :
1475 : : /* Remove the devices we created ourselves as the result of hardware
1476 : : * probing (using a driver's detect method) */
1477 [ # # ]: 0 : list_for_each_entry_safe(client, _n, &driver->clients, detected) {
1478 [ # # ]: 0 : if (client->adapter == adapter) {
1479 : 0 : dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",
1480 : : client->name, client->addr);
1481 : 0 : list_del(&client->detected);
1482 : 0 : i2c_unregister_device(client);
1483 : : }
1484 : : }
1485 : 0 : }
1486 : :
1487 : 0 : static int __unregister_client(struct device *dev, void *dummy)
1488 : : {
1489 [ # # ]: 0 : struct i2c_client *client = i2c_verify_client(dev);
1490 [ # # # # ]: 0 : if (client && strcmp(client->name, "dummy"))
1491 : 0 : i2c_unregister_device(client);
1492 : 0 : return 0;
1493 : : }
1494 : :
1495 : 0 : static int __unregister_dummy(struct device *dev, void *dummy)
1496 : : {
1497 [ # # ]: 0 : struct i2c_client *client = i2c_verify_client(dev);
1498 : 0 : i2c_unregister_device(client);
1499 : 0 : return 0;
1500 : : }
1501 : :
1502 : 0 : static int __process_removed_adapter(struct device_driver *d, void *data)
1503 : : {
1504 : 0 : i2c_do_del_adapter(to_i2c_driver(d), data);
1505 : 0 : return 0;
1506 : : }
1507 : :
1508 : : /**
1509 : : * i2c_del_adapter - unregister I2C adapter
1510 : : * @adap: the adapter being unregistered
1511 : : * Context: can sleep
1512 : : *
1513 : : * This unregisters an I2C adapter which was previously registered
1514 : : * by @i2c_add_adapter or @i2c_add_numbered_adapter.
1515 : : */
1516 : 0 : void i2c_del_adapter(struct i2c_adapter *adap)
1517 : : {
1518 : 0 : struct i2c_adapter *found;
1519 : 0 : struct i2c_client *client, *next;
1520 : :
1521 : : /* First make sure that this adapter was ever added */
1522 : 0 : mutex_lock(&core_lock);
1523 : 0 : found = idr_find(&i2c_adapter_idr, adap->nr);
1524 : 0 : mutex_unlock(&core_lock);
1525 [ # # ]: 0 : if (found != adap) {
1526 : : pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name);
1527 : : return;
1528 : : }
1529 : :
1530 : 0 : i2c_acpi_remove_space_handler(adap);
1531 : : /* Tell drivers about this removal */
1532 : 0 : mutex_lock(&core_lock);
1533 : 0 : bus_for_each_drv(&i2c_bus_type, NULL, adap,
1534 : : __process_removed_adapter);
1535 : 0 : mutex_unlock(&core_lock);
1536 : :
1537 : : /* Remove devices instantiated from sysfs */
1538 : 0 : mutex_lock_nested(&adap->userspace_clients_lock,
1539 : : i2c_adapter_depth(adap));
1540 [ # # ]: 0 : list_for_each_entry_safe(client, next, &adap->userspace_clients,
1541 : : detected) {
1542 : 0 : dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,
1543 : : client->addr);
1544 : 0 : list_del(&client->detected);
1545 : 0 : i2c_unregister_device(client);
1546 : : }
1547 : 0 : mutex_unlock(&adap->userspace_clients_lock);
1548 : :
1549 : : /* Detach any active clients. This can't fail, thus we do not
1550 : : * check the returned value. This is a two-pass process, because
1551 : : * we can't remove the dummy devices during the first pass: they
1552 : : * could have been instantiated by real devices wishing to clean
1553 : : * them up properly, so we give them a chance to do that first. */
1554 : 0 : device_for_each_child(&adap->dev, NULL, __unregister_client);
1555 : 0 : device_for_each_child(&adap->dev, NULL, __unregister_dummy);
1556 : :
1557 : : #ifdef CONFIG_I2C_COMPAT
1558 : 0 : class_compat_remove_link(i2c_adapter_compat_class, &adap->dev,
1559 : : adap->dev.parent);
1560 : : #endif
1561 : :
1562 : : /* device name is gone after device_unregister */
1563 : 0 : dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
1564 : :
1565 : 0 : pm_runtime_disable(&adap->dev);
1566 : :
1567 : 0 : i2c_host_notify_irq_teardown(adap);
1568 : :
1569 : : /* wait until all references to the device are gone
1570 : : *
1571 : : * FIXME: This is old code and should ideally be replaced by an
1572 : : * alternative which results in decoupling the lifetime of the struct
1573 : : * device from the i2c_adapter, like spi or netdev do. Any solution
1574 : : * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled!
1575 : : */
1576 : 0 : init_completion(&adap->dev_released);
1577 : 0 : device_unregister(&adap->dev);
1578 : 0 : wait_for_completion(&adap->dev_released);
1579 : :
1580 : : /* free bus id */
1581 : 0 : mutex_lock(&core_lock);
1582 : 0 : idr_remove(&i2c_adapter_idr, adap->nr);
1583 : 0 : mutex_unlock(&core_lock);
1584 : :
1585 : : /* Clear the device structure in case this adapter is ever going to be
1586 : : added again */
1587 : 0 : memset(&adap->dev, 0, sizeof(adap->dev));
1588 : : }
1589 : : EXPORT_SYMBOL(i2c_del_adapter);
1590 : :
1591 : : /**
1592 : : * i2c_parse_fw_timings - get I2C related timing parameters from firmware
1593 : : * @dev: The device to scan for I2C timing properties
1594 : : * @t: the i2c_timings struct to be filled with values
1595 : : * @use_defaults: bool to use sane defaults derived from the I2C specification
1596 : : * when properties are not found, otherwise use 0
1597 : : *
1598 : : * Scan the device for the generic I2C properties describing timing parameters
1599 : : * for the signal and fill the given struct with the results. If a property was
1600 : : * not found and use_defaults was true, then maximum timings are assumed which
1601 : : * are derived from the I2C specification. If use_defaults is not used, the
1602 : : * results will be 0, so drivers can apply their own defaults later. The latter
1603 : : * is mainly intended for avoiding regressions of existing drivers which want
1604 : : * to switch to this function. New drivers almost always should use the defaults.
1605 : : */
1606 : :
1607 : 0 : void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults)
1608 : : {
1609 : 0 : int ret;
1610 : :
1611 : 0 : memset(t, 0, sizeof(*t));
1612 : :
1613 : 0 : ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz);
1614 [ # # ]: 0 : if (ret && use_defaults)
1615 : 0 : t->bus_freq_hz = 100000;
1616 : :
1617 : 0 : ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns);
1618 [ # # ]: 0 : if (ret && use_defaults) {
1619 [ # # ]: 0 : if (t->bus_freq_hz <= 100000)
1620 : 0 : t->scl_rise_ns = 1000;
1621 [ # # ]: 0 : else if (t->bus_freq_hz <= 400000)
1622 : 0 : t->scl_rise_ns = 300;
1623 : : else
1624 : 0 : t->scl_rise_ns = 120;
1625 : : }
1626 : :
1627 : 0 : ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns);
1628 [ # # ]: 0 : if (ret && use_defaults) {
1629 [ # # ]: 0 : if (t->bus_freq_hz <= 400000)
1630 : 0 : t->scl_fall_ns = 300;
1631 : : else
1632 : 0 : t->scl_fall_ns = 120;
1633 : : }
1634 : :
1635 : 0 : device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns);
1636 : :
1637 : 0 : ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns);
1638 [ # # ]: 0 : if (ret && use_defaults)
1639 : 0 : t->sda_fall_ns = t->scl_fall_ns;
1640 : :
1641 : 0 : device_property_read_u32(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns);
1642 : :
1643 : 0 : device_property_read_u32(dev, "i2c-digital-filter-width-ns",
1644 : : &t->digital_filter_width_ns);
1645 : :
1646 : 0 : device_property_read_u32(dev, "i2c-analog-filter-cutoff-frequency",
1647 : : &t->analog_filter_cutoff_freq_hz);
1648 : 0 : }
1649 : : EXPORT_SYMBOL_GPL(i2c_parse_fw_timings);
1650 : :
1651 : : /* ------------------------------------------------------------------------- */
1652 : :
1653 : 42 : int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data))
1654 : : {
1655 : 42 : int res;
1656 : :
1657 : 42 : mutex_lock(&core_lock);
1658 : 42 : res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn);
1659 : 42 : mutex_unlock(&core_lock);
1660 : :
1661 : 42 : return res;
1662 : : }
1663 : : EXPORT_SYMBOL_GPL(i2c_for_each_dev);
1664 : :
1665 : 0 : static int __process_new_driver(struct device *dev, void *data)
1666 : : {
1667 [ # # ]: 0 : if (dev->type != &i2c_adapter_type)
1668 : : return 0;
1669 : 0 : return i2c_do_add_adapter(data, to_i2c_adapter(dev));
1670 : : }
1671 : :
1672 : : /*
1673 : : * An i2c_driver is used with one or more i2c_client (device) nodes to access
1674 : : * i2c slave chips, on a bus instance associated with some i2c_adapter.
1675 : : */
1676 : :
1677 : 42 : int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
1678 : : {
1679 : 42 : int res;
1680 : :
1681 : : /* Can't register until after driver model init */
1682 [ - + + - ]: 42 : if (WARN_ON(!is_registered))
1683 : : return -EAGAIN;
1684 : :
1685 : : /* add the driver to the list of i2c drivers in the driver core */
1686 : 42 : driver->driver.owner = owner;
1687 : 42 : driver->driver.bus = &i2c_bus_type;
1688 : 42 : INIT_LIST_HEAD(&driver->clients);
1689 : :
1690 : : /* When registration returns, the driver core
1691 : : * will have called probe() for all matching-but-unbound devices.
1692 : : */
1693 : 42 : res = driver_register(&driver->driver);
1694 [ + - ]: 42 : if (res)
1695 : : return res;
1696 : :
1697 : 42 : pr_debug("driver [%s] registered\n", driver->driver.name);
1698 : :
1699 : : /* Walk the adapters that are already present */
1700 : 42 : i2c_for_each_dev(driver, __process_new_driver);
1701 : :
1702 : 42 : return 0;
1703 : : }
1704 : : EXPORT_SYMBOL(i2c_register_driver);
1705 : :
1706 : 0 : static int __process_removed_driver(struct device *dev, void *data)
1707 : : {
1708 [ # # ]: 0 : if (dev->type == &i2c_adapter_type)
1709 : 0 : i2c_do_del_adapter(data, to_i2c_adapter(dev));
1710 : 0 : return 0;
1711 : : }
1712 : :
1713 : : /**
1714 : : * i2c_del_driver - unregister I2C driver
1715 : : * @driver: the driver being unregistered
1716 : : * Context: can sleep
1717 : : */
1718 : 0 : void i2c_del_driver(struct i2c_driver *driver)
1719 : : {
1720 : 0 : i2c_for_each_dev(driver, __process_removed_driver);
1721 : :
1722 : 0 : driver_unregister(&driver->driver);
1723 : 0 : pr_debug("driver [%s] unregistered\n", driver->driver.name);
1724 : 0 : }
1725 : : EXPORT_SYMBOL(i2c_del_driver);
1726 : :
1727 : : /* ------------------------------------------------------------------------- */
1728 : :
1729 : : struct i2c_cmd_arg {
1730 : : unsigned cmd;
1731 : : void *arg;
1732 : : };
1733 : :
1734 : 0 : static int i2c_cmd(struct device *dev, void *_arg)
1735 : : {
1736 [ # # ]: 0 : struct i2c_client *client = i2c_verify_client(dev);
1737 : 0 : struct i2c_cmd_arg *arg = _arg;
1738 : 0 : struct i2c_driver *driver;
1739 : :
1740 [ # # # # ]: 0 : if (!client || !client->dev.driver)
1741 : : return 0;
1742 : :
1743 : 0 : driver = to_i2c_driver(client->dev.driver);
1744 [ # # ]: 0 : if (driver->command)
1745 : 0 : driver->command(client, arg->cmd, arg->arg);
1746 : : return 0;
1747 : : }
1748 : :
1749 : 0 : void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
1750 : : {
1751 : 0 : struct i2c_cmd_arg cmd_arg;
1752 : :
1753 : 0 : cmd_arg.cmd = cmd;
1754 : 0 : cmd_arg.arg = arg;
1755 : 0 : device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);
1756 : 0 : }
1757 : : EXPORT_SYMBOL(i2c_clients_command);
1758 : :
1759 : 21 : static int __init i2c_init(void)
1760 : : {
1761 : 21 : int retval;
1762 : :
1763 : 21 : retval = of_alias_get_highest_id("i2c");
1764 : :
1765 : 21 : down_write(&__i2c_board_lock);
1766 [ - + ]: 21 : if (retval >= __i2c_first_dynamic_bus_num)
1767 : 0 : __i2c_first_dynamic_bus_num = retval + 1;
1768 : 21 : up_write(&__i2c_board_lock);
1769 : :
1770 : 21 : retval = bus_register(&i2c_bus_type);
1771 [ + - ]: 21 : if (retval)
1772 : : return retval;
1773 : :
1774 : 21 : is_registered = true;
1775 : :
1776 : : #ifdef CONFIG_I2C_COMPAT
1777 : 21 : i2c_adapter_compat_class = class_compat_register("i2c-adapter");
1778 [ - + ]: 21 : if (!i2c_adapter_compat_class) {
1779 : 0 : retval = -ENOMEM;
1780 : 0 : goto bus_err;
1781 : : }
1782 : : #endif
1783 : 21 : retval = i2c_add_driver(&dummy_driver);
1784 [ - + ]: 21 : if (retval)
1785 : 0 : goto class_err;
1786 : :
1787 : 21 : if (IS_ENABLED(CONFIG_OF_DYNAMIC))
1788 : : WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier));
1789 : 21 : if (IS_ENABLED(CONFIG_ACPI))
1790 [ - + ]: 21 : WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier));
1791 : :
1792 : : return 0;
1793 : :
1794 : : class_err:
1795 : : #ifdef CONFIG_I2C_COMPAT
1796 : 0 : class_compat_unregister(i2c_adapter_compat_class);
1797 : 0 : bus_err:
1798 : : #endif
1799 : 0 : is_registered = false;
1800 : 0 : bus_unregister(&i2c_bus_type);
1801 : 0 : return retval;
1802 : : }
1803 : :
1804 : 0 : static void __exit i2c_exit(void)
1805 : : {
1806 : 0 : if (IS_ENABLED(CONFIG_ACPI))
1807 [ # # ]: 0 : WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier));
1808 : 0 : if (IS_ENABLED(CONFIG_OF_DYNAMIC))
1809 : : WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier));
1810 : 0 : i2c_del_driver(&dummy_driver);
1811 : : #ifdef CONFIG_I2C_COMPAT
1812 : 0 : class_compat_unregister(i2c_adapter_compat_class);
1813 : : #endif
1814 : 0 : bus_unregister(&i2c_bus_type);
1815 : 0 : tracepoint_synchronize_unregister();
1816 : 0 : }
1817 : :
1818 : : /* We must initialize early, because some subsystems register i2c drivers
1819 : : * in subsys_initcall() code, but are linked (and initialized) before i2c.
1820 : : */
1821 : : postcore_initcall(i2c_init);
1822 : : module_exit(i2c_exit);
1823 : :
1824 : : /* ----------------------------------------------------
1825 : : * the functional interface to the i2c busses.
1826 : : * ----------------------------------------------------
1827 : : */
1828 : :
1829 : : /* Check if val is exceeding the quirk IFF quirk is non 0 */
1830 : : #define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk)))
1831 : :
1832 : 0 : static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg)
1833 : : {
1834 [ # # # # ]: 0 : dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n",
1835 : : err_msg, msg->addr, msg->len,
1836 : : msg->flags & I2C_M_RD ? "read" : "write");
1837 : 0 : return -EOPNOTSUPP;
1838 : : }
1839 : :
1840 : 0 : static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
1841 : : {
1842 : 0 : const struct i2c_adapter_quirks *q = adap->quirks;
1843 : 0 : int max_num = q->max_num_msgs, i;
1844 : 0 : bool do_len_check = true;
1845 : :
1846 [ # # ]: 0 : if (q->flags & I2C_AQ_COMB) {
1847 : 0 : max_num = 2;
1848 : :
1849 : : /* special checks for combined messages */
1850 [ # # ]: 0 : if (num == 2) {
1851 [ # # # # ]: 0 : if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD)
1852 : 0 : return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write");
1853 : :
1854 [ # # # # ]: 0 : if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD))
1855 : 0 : return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read");
1856 : :
1857 [ # # # # ]: 0 : if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr)
1858 : 0 : return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr");
1859 : :
1860 [ # # # # ]: 0 : if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len))
1861 : 0 : return i2c_quirk_error(adap, &msgs[0], "msg too long");
1862 : :
1863 [ # # # # ]: 0 : if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len))
1864 : 0 : return i2c_quirk_error(adap, &msgs[1], "msg too long");
1865 : :
1866 : : do_len_check = false;
1867 : : }
1868 : : }
1869 : :
1870 [ # # ]: 0 : if (i2c_quirk_exceeded(num, max_num))
1871 : 0 : return i2c_quirk_error(adap, &msgs[0], "too many messages");
1872 : :
1873 [ # # ]: 0 : for (i = 0; i < num; i++) {
1874 : 0 : u16 len = msgs[i].len;
1875 : :
1876 [ # # ]: 0 : if (msgs[i].flags & I2C_M_RD) {
1877 [ # # # # : 0 : if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len))
# # ]
1878 : 0 : return i2c_quirk_error(adap, &msgs[i], "msg too long");
1879 : :
1880 [ # # # # ]: 0 : if (q->flags & I2C_AQ_NO_ZERO_LEN_READ && len == 0)
1881 : 0 : return i2c_quirk_error(adap, &msgs[i], "no zero length");
1882 : : } else {
1883 [ # # # # : 0 : if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len))
# # ]
1884 : 0 : return i2c_quirk_error(adap, &msgs[i], "msg too long");
1885 : :
1886 [ # # # # ]: 0 : if (q->flags & I2C_AQ_NO_ZERO_LEN_WRITE && len == 0)
1887 : 0 : return i2c_quirk_error(adap, &msgs[i], "no zero length");
1888 : : }
1889 : : }
1890 : :
1891 : : return 0;
1892 : : }
1893 : :
1894 : : /**
1895 : : * __i2c_transfer - unlocked flavor of i2c_transfer
1896 : : * @adap: Handle to I2C bus
1897 : : * @msgs: One or more messages to execute before STOP is issued to
1898 : : * terminate the operation; each message begins with a START.
1899 : : * @num: Number of messages to be executed.
1900 : : *
1901 : : * Returns negative errno, else the number of messages executed.
1902 : : *
1903 : : * Adapter lock must be held when calling this function. No debug logging
1904 : : * takes place. adap->algo->master_xfer existence isn't checked.
1905 : : */
1906 : 0 : int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
1907 : : {
1908 : 0 : unsigned long orig_jiffies;
1909 : 0 : int ret, try;
1910 : :
1911 [ # # # # ]: 0 : if (WARN_ON(!msgs || num < 1))
1912 : : return -EINVAL;
1913 : :
1914 : 0 : ret = __i2c_check_suspended(adap);
1915 [ # # ]: 0 : if (ret)
1916 : : return ret;
1917 : :
1918 [ # # # # ]: 0 : if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))
1919 : : return -EOPNOTSUPP;
1920 : :
1921 : : /*
1922 : : * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets
1923 : : * enabled. This is an efficient way of keeping the for-loop from
1924 : : * being executed when not needed.
1925 : : */
1926 [ # # # # ]: 0 : if (static_branch_unlikely(&i2c_trace_msg_key)) {
1927 : : int i;
1928 [ # # ]: 0 : for (i = 0; i < num; i++)
1929 [ # # ]: 0 : if (msgs[i].flags & I2C_M_RD)
1930 : 0 : trace_i2c_read(adap, &msgs[i], i);
1931 : : else
1932 : 0 : trace_i2c_write(adap, &msgs[i], i);
1933 : : }
1934 : :
1935 : : /* Retry automatically on arbitration loss */
1936 : 0 : orig_jiffies = jiffies;
1937 [ # # ]: 0 : for (ret = 0, try = 0; try <= adap->retries; try++) {
1938 [ # # # # : 0 : if (i2c_in_atomic_xfer_mode() && adap->algo->master_xfer_atomic)
# # ]
1939 : 0 : ret = adap->algo->master_xfer_atomic(adap, msgs, num);
1940 : : else
1941 : 0 : ret = adap->algo->master_xfer(adap, msgs, num);
1942 : :
1943 [ # # ]: 0 : if (ret != -EAGAIN)
1944 : : break;
1945 [ # # ]: 0 : if (time_after(jiffies, orig_jiffies + adap->timeout))
1946 : : break;
1947 : : }
1948 : :
1949 [ # # # # ]: 0 : if (static_branch_unlikely(&i2c_trace_msg_key)) {
1950 : : int i;
1951 [ # # ]: 0 : for (i = 0; i < ret; i++)
1952 [ # # ]: 0 : if (msgs[i].flags & I2C_M_RD)
1953 : 0 : trace_i2c_reply(adap, &msgs[i], i);
1954 : 0 : trace_i2c_result(adap, num, ret);
1955 : : }
1956 : :
1957 : : return ret;
1958 : : }
1959 : : EXPORT_SYMBOL(__i2c_transfer);
1960 : :
1961 : : /**
1962 : : * i2c_transfer - execute a single or combined I2C message
1963 : : * @adap: Handle to I2C bus
1964 : : * @msgs: One or more messages to execute before STOP is issued to
1965 : : * terminate the operation; each message begins with a START.
1966 : : * @num: Number of messages to be executed.
1967 : : *
1968 : : * Returns negative errno, else the number of messages executed.
1969 : : *
1970 : : * Note that there is no requirement that each message be sent to
1971 : : * the same slave address, although that is the most common model.
1972 : : */
1973 : 0 : int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
1974 : : {
1975 : 0 : int ret;
1976 : :
1977 [ # # ]: 0 : if (!adap->algo->master_xfer) {
1978 : : dev_dbg(&adap->dev, "I2C level transfers not supported\n");
1979 : : return -EOPNOTSUPP;
1980 : : }
1981 : :
1982 : : /* REVISIT the fault reporting model here is weak:
1983 : : *
1984 : : * - When we get an error after receiving N bytes from a slave,
1985 : : * there is no way to report "N".
1986 : : *
1987 : : * - When we get a NAK after transmitting N bytes to a slave,
1988 : : * there is no way to report "N" ... or to let the master
1989 : : * continue executing the rest of this combined message, if
1990 : : * that's the appropriate response.
1991 : : *
1992 : : * - When for example "num" is two and we successfully complete
1993 : : * the first message but get an error part way through the
1994 : : * second, it's unclear whether that should be reported as
1995 : : * one (discarding status on the second message) or errno
1996 : : * (discarding status on the first one).
1997 : : */
1998 : 0 : ret = __i2c_lock_bus_helper(adap);
1999 [ # # ]: 0 : if (ret)
2000 : : return ret;
2001 : :
2002 : 0 : ret = __i2c_transfer(adap, msgs, num);
2003 : 0 : i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
2004 : :
2005 : 0 : return ret;
2006 : : }
2007 : : EXPORT_SYMBOL(i2c_transfer);
2008 : :
2009 : : /**
2010 : : * i2c_transfer_buffer_flags - issue a single I2C message transferring data
2011 : : * to/from a buffer
2012 : : * @client: Handle to slave device
2013 : : * @buf: Where the data is stored
2014 : : * @count: How many bytes to transfer, must be less than 64k since msg.len is u16
2015 : : * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads
2016 : : *
2017 : : * Returns negative errno, or else the number of bytes transferred.
2018 : : */
2019 : 0 : int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf,
2020 : : int count, u16 flags)
2021 : : {
2022 : 0 : int ret;
2023 : 0 : struct i2c_msg msg = {
2024 : 0 : .addr = client->addr,
2025 : 0 : .flags = flags | (client->flags & I2C_M_TEN),
2026 : : .len = count,
2027 : : .buf = buf,
2028 : : };
2029 : :
2030 : 0 : ret = i2c_transfer(client->adapter, &msg, 1);
2031 : :
2032 : : /*
2033 : : * If everything went ok (i.e. 1 msg transferred), return #bytes
2034 : : * transferred, else error code.
2035 : : */
2036 [ # # ]: 0 : return (ret == 1) ? count : ret;
2037 : : }
2038 : : EXPORT_SYMBOL(i2c_transfer_buffer_flags);
2039 : :
2040 : : /**
2041 : : * i2c_get_device_id - get manufacturer, part id and die revision of a device
2042 : : * @client: The device to query
2043 : : * @id: The queried information
2044 : : *
2045 : : * Returns negative errno on error, zero on success.
2046 : : */
2047 : 0 : int i2c_get_device_id(const struct i2c_client *client,
2048 : : struct i2c_device_identity *id)
2049 : : {
2050 : 0 : struct i2c_adapter *adap = client->adapter;
2051 : 0 : union i2c_smbus_data raw_id;
2052 : 0 : int ret;
2053 : :
2054 [ # # ]: 0 : if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
2055 : : return -EOPNOTSUPP;
2056 : :
2057 : 0 : raw_id.block[0] = 3;
2058 : 0 : ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0,
2059 : 0 : I2C_SMBUS_READ, client->addr << 1,
2060 : : I2C_SMBUS_I2C_BLOCK_DATA, &raw_id);
2061 [ # # ]: 0 : if (ret)
2062 : : return ret;
2063 : :
2064 : 0 : id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4);
2065 : 0 : id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3);
2066 : 0 : id->die_revision = raw_id.block[3] & 0x7;
2067 : 0 : return 0;
2068 : : }
2069 : : EXPORT_SYMBOL_GPL(i2c_get_device_id);
2070 : :
2071 : : /* ----------------------------------------------------
2072 : : * the i2c address scanning function
2073 : : * Will not work for 10-bit addresses!
2074 : : * ----------------------------------------------------
2075 : : */
2076 : :
2077 : : /*
2078 : : * Legacy default probe function, mostly relevant for SMBus. The default
2079 : : * probe method is a quick write, but it is known to corrupt the 24RF08
2080 : : * EEPROMs due to a state machine bug, and could also irreversibly
2081 : : * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f,
2082 : : * we use a short byte read instead. Also, some bus drivers don't implement
2083 : : * quick write, so we fallback to a byte read in that case too.
2084 : : * On x86, there is another special case for FSC hardware monitoring chips,
2085 : : * which want regular byte reads (address 0x73.) Fortunately, these are the
2086 : : * only known chips using this I2C address on PC hardware.
2087 : : * Returns 1 if probe succeeded, 0 if not.
2088 : : */
2089 : 0 : static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr)
2090 : : {
2091 : 0 : int err;
2092 : 0 : union i2c_smbus_data dummy;
2093 : :
2094 : : #ifdef CONFIG_X86
2095 [ # # # # ]: 0 : if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON)
2096 [ # # ]: 0 : && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA))
2097 : 0 : err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
2098 : : I2C_SMBUS_BYTE_DATA, &dummy);
2099 : : else
2100 : : #endif
2101 [ # # # # ]: 0 : if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50)
2102 [ # # ]: 0 : && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK))
2103 : 0 : err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0,
2104 : : I2C_SMBUS_QUICK, NULL);
2105 [ # # ]: 0 : else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE))
2106 : 0 : err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
2107 : : I2C_SMBUS_BYTE, &dummy);
2108 : : else {
2109 : 0 : dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n",
2110 : : addr);
2111 : 0 : err = -EOPNOTSUPP;
2112 : : }
2113 : :
2114 : 0 : return err >= 0;
2115 : : }
2116 : :
2117 : 0 : static int i2c_detect_address(struct i2c_client *temp_client,
2118 : : struct i2c_driver *driver)
2119 : : {
2120 : 0 : struct i2c_board_info info;
2121 : 0 : struct i2c_adapter *adapter = temp_client->adapter;
2122 : 0 : int addr = temp_client->addr;
2123 : 0 : int err;
2124 : :
2125 : : /* Make sure the address is valid */
2126 [ # # ]: 0 : err = i2c_check_7bit_addr_validity_strict(addr);
2127 : 0 : if (err) {
2128 : 0 : dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
2129 : : addr);
2130 : 0 : return err;
2131 : : }
2132 : :
2133 : : /* Skip if already in use (7 bit, no need to encode flags) */
2134 [ # # ]: 0 : if (i2c_check_addr_busy(adapter, addr))
2135 : : return 0;
2136 : :
2137 : : /* Make sure there is something at this address */
2138 [ # # ]: 0 : if (!i2c_default_probe(adapter, addr))
2139 : : return 0;
2140 : :
2141 : : /* Finally call the custom detection function */
2142 : 0 : memset(&info, 0, sizeof(struct i2c_board_info));
2143 : 0 : info.addr = addr;
2144 : 0 : err = driver->detect(temp_client, &info);
2145 [ # # ]: 0 : if (err) {
2146 : : /* -ENODEV is returned if the detection fails. We catch it
2147 : : here as this isn't an error. */
2148 [ # # ]: 0 : return err == -ENODEV ? 0 : err;
2149 : : }
2150 : :
2151 : : /* Consistency check */
2152 [ # # ]: 0 : if (info.type[0] == '\0') {
2153 : 0 : dev_err(&adapter->dev,
2154 : : "%s detection function provided no name for 0x%x\n",
2155 : : driver->driver.name, addr);
2156 : : } else {
2157 : 0 : struct i2c_client *client;
2158 : :
2159 : : /* Detection succeeded, instantiate the device */
2160 [ # # ]: 0 : if (adapter->class & I2C_CLASS_DEPRECATED)
2161 : 0 : dev_warn(&adapter->dev,
2162 : : "This adapter will soon drop class based instantiation of devices. "
2163 : : "Please make sure client 0x%02x gets instantiated by other means. "
2164 : : "Check 'Documentation/i2c/instantiating-devices.rst' for details.\n",
2165 : : info.addr);
2166 : :
2167 : 0 : dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
2168 : : info.type, info.addr);
2169 : 0 : client = i2c_new_client_device(adapter, &info);
2170 [ # # ]: 0 : if (!IS_ERR(client))
2171 : 0 : list_add_tail(&client->detected, &driver->clients);
2172 : : else
2173 : 0 : dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n",
2174 : : info.type, info.addr);
2175 : : }
2176 : : return 0;
2177 : : }
2178 : :
2179 : 0 : static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
2180 : : {
2181 : 0 : const unsigned short *address_list;
2182 : 0 : struct i2c_client *temp_client;
2183 : 0 : int i, err = 0;
2184 [ # # ]: 0 : int adap_id = i2c_adapter_id(adapter);
2185 : :
2186 : 0 : address_list = driver->address_list;
2187 [ # # # # ]: 0 : if (!driver->detect || !address_list)
2188 : : return 0;
2189 : :
2190 : : /* Warn that the adapter lost class based instantiation */
2191 [ # # ]: 0 : if (adapter->class == I2C_CLASS_DEPRECATED) {
2192 : : dev_dbg(&adapter->dev,
2193 : : "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. "
2194 : : "If you need it, check 'Documentation/i2c/instantiating-devices.rst' for alternatives.\n",
2195 : : driver->driver.name);
2196 : : return 0;
2197 : : }
2198 : :
2199 : : /* Stop here if the classes do not match */
2200 [ # # ]: 0 : if (!(adapter->class & driver->class))
2201 : : return 0;
2202 : :
2203 : : /* Set up a temporary client to help detect callback */
2204 : 0 : temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
2205 [ # # ]: 0 : if (!temp_client)
2206 : : return -ENOMEM;
2207 : 0 : temp_client->adapter = adapter;
2208 : :
2209 [ # # ]: 0 : for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {
2210 : 0 : dev_dbg(&adapter->dev,
2211 : : "found normal entry for adapter %d, addr 0x%02x\n",
2212 : : adap_id, address_list[i]);
2213 : 0 : temp_client->addr = address_list[i];
2214 : 0 : err = i2c_detect_address(temp_client, driver);
2215 [ # # ]: 0 : if (unlikely(err))
2216 : : break;
2217 : : }
2218 : :
2219 : 0 : kfree(temp_client);
2220 : 0 : return err;
2221 : : }
2222 : :
2223 : 0 : int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr)
2224 : : {
2225 : 0 : return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
2226 : 0 : I2C_SMBUS_QUICK, NULL) >= 0;
2227 : : }
2228 : : EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read);
2229 : :
2230 : : struct i2c_client *
2231 : 0 : i2c_new_scanned_device(struct i2c_adapter *adap,
2232 : : struct i2c_board_info *info,
2233 : : unsigned short const *addr_list,
2234 : : int (*probe)(struct i2c_adapter *adap, unsigned short addr))
2235 : : {
2236 : 0 : int i;
2237 : :
2238 [ # # ]: 0 : if (!probe)
2239 : 0 : probe = i2c_default_probe;
2240 : :
2241 [ # # ]: 0 : for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
2242 : : /* Check address validity */
2243 [ # # ]: 0 : if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) {
2244 : 0 : dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n",
2245 : : addr_list[i]);
2246 : 0 : continue;
2247 : : }
2248 : :
2249 : : /* Check address availability (7 bit, no need to encode flags) */
2250 [ # # ]: 0 : if (i2c_check_addr_busy(adap, addr_list[i])) {
2251 : 0 : dev_dbg(&adap->dev,
2252 : : "Address 0x%02x already in use, not probing\n",
2253 : : addr_list[i]);
2254 : 0 : continue;
2255 : : }
2256 : :
2257 : : /* Test address responsiveness */
2258 [ # # ]: 0 : if (probe(adap, addr_list[i]))
2259 : : break;
2260 : : }
2261 : :
2262 [ # # ]: 0 : if (addr_list[i] == I2C_CLIENT_END) {
2263 : : dev_dbg(&adap->dev, "Probing failed, no device found\n");
2264 : : return ERR_PTR(-ENODEV);
2265 : : }
2266 : :
2267 : 0 : info->addr = addr_list[i];
2268 : 0 : return i2c_new_client_device(adap, info);
2269 : : }
2270 : : EXPORT_SYMBOL_GPL(i2c_new_scanned_device);
2271 : :
2272 : : struct i2c_client *
2273 : 0 : i2c_new_probed_device(struct i2c_adapter *adap,
2274 : : struct i2c_board_info *info,
2275 : : unsigned short const *addr_list,
2276 : : int (*probe)(struct i2c_adapter *adap, unsigned short addr))
2277 : : {
2278 : 0 : struct i2c_client *client;
2279 : :
2280 : 0 : client = i2c_new_scanned_device(adap, info, addr_list, probe);
2281 [ # # ]: 0 : return IS_ERR(client) ? NULL : client;
2282 : : }
2283 : : EXPORT_SYMBOL_GPL(i2c_new_probed_device);
2284 : :
2285 : 0 : struct i2c_adapter *i2c_get_adapter(int nr)
2286 : : {
2287 : 0 : struct i2c_adapter *adapter;
2288 : :
2289 : 0 : mutex_lock(&core_lock);
2290 : 0 : adapter = idr_find(&i2c_adapter_idr, nr);
2291 [ # # ]: 0 : if (!adapter)
2292 : 0 : goto exit;
2293 : :
2294 [ # # ]: 0 : if (try_module_get(adapter->owner))
2295 : 0 : get_device(&adapter->dev);
2296 : : else
2297 : : adapter = NULL;
2298 : :
2299 : 0 : exit:
2300 : 0 : mutex_unlock(&core_lock);
2301 : 0 : return adapter;
2302 : : }
2303 : : EXPORT_SYMBOL(i2c_get_adapter);
2304 : :
2305 : 0 : void i2c_put_adapter(struct i2c_adapter *adap)
2306 : : {
2307 [ # # ]: 0 : if (!adap)
2308 : : return;
2309 : :
2310 : 0 : put_device(&adap->dev);
2311 : 0 : module_put(adap->owner);
2312 : : }
2313 : : EXPORT_SYMBOL(i2c_put_adapter);
2314 : :
2315 : : /**
2316 : : * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg
2317 : : * @msg: the message to be checked
2318 : : * @threshold: the minimum number of bytes for which using DMA makes sense.
2319 : : * Should at least be 1.
2320 : : *
2321 : : * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO.
2322 : : * Or a valid pointer to be used with DMA. After use, release it by
2323 : : * calling i2c_put_dma_safe_msg_buf().
2324 : : *
2325 : : * This function must only be called from process context!
2326 : : */
2327 : 0 : u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold)
2328 : : {
2329 : : /* also skip 0-length msgs for bogus thresholds of 0 */
2330 : 0 : if (!threshold)
2331 : : pr_debug("DMA buffer for addr=0x%02x with length 0 is bogus\n",
2332 : : msg->addr);
2333 [ # # # # ]: 0 : if (msg->len < threshold || msg->len == 0)
2334 : : return NULL;
2335 : :
2336 [ # # ]: 0 : if (msg->flags & I2C_M_DMA_SAFE)
2337 : 0 : return msg->buf;
2338 : :
2339 : 0 : pr_debug("using bounce buffer for addr=0x%02x, len=%d\n",
2340 : : msg->addr, msg->len);
2341 : :
2342 [ # # ]: 0 : if (msg->flags & I2C_M_RD)
2343 : 0 : return kzalloc(msg->len, GFP_KERNEL);
2344 : : else
2345 : 0 : return kmemdup(msg->buf, msg->len, GFP_KERNEL);
2346 : : }
2347 : : EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf);
2348 : :
2349 : : /**
2350 : : * i2c_put_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg
2351 : : * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL.
2352 : : * @msg: the message which the buffer corresponds to
2353 : : * @xferred: bool saying if the message was transferred
2354 : : */
2355 : 0 : void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred)
2356 : : {
2357 [ # # # # ]: 0 : if (!buf || buf == msg->buf)
2358 : : return;
2359 : :
2360 [ # # # # ]: 0 : if (xferred && msg->flags & I2C_M_RD)
2361 : 0 : memcpy(msg->buf, buf, msg->len);
2362 : :
2363 : 0 : kfree(buf);
2364 : : }
2365 : : EXPORT_SYMBOL_GPL(i2c_put_dma_safe_msg_buf);
2366 : :
2367 : : MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
2368 : : MODULE_DESCRIPTION("I2C-Bus main module");
2369 : : MODULE_LICENSE("GPL");
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