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@kernel.org>
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/interrupt.h>
28 : #include <linux/irqflags.h>
29 : #include <linux/jump_label.h>
30 : #include <linux/kernel.h>
31 : #include <linux/module.h>
32 : #include <linux/mutex.h>
33 : #include <linux/of_device.h>
34 : #include <linux/of.h>
35 : #include <linux/of_irq.h>
36 : #include <linux/pinctrl/consumer.h>
37 : #include <linux/pm_domain.h>
38 : #include <linux/pm_runtime.h>
39 : #include <linux/pm_wakeirq.h>
40 : #include <linux/property.h>
41 : #include <linux/rwsem.h>
42 : #include <linux/slab.h>
43 :
44 : #include "i2c-core.h"
45 :
46 : #define CREATE_TRACE_POINTS
47 : #include <trace/events/i2c.h>
48 :
49 : #define I2C_ADDR_OFFSET_TEN_BIT 0xa000
50 : #define I2C_ADDR_OFFSET_SLAVE 0x1000
51 :
52 : #define I2C_ADDR_7BITS_MAX 0x77
53 : #define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1)
54 :
55 : #define I2C_ADDR_DEVICE_ID 0x7c
56 :
57 : /*
58 : * core_lock protects i2c_adapter_idr, and guarantees that device detection,
59 : * deletion of detected devices are serialized
60 : */
61 : static DEFINE_MUTEX(core_lock);
62 : static DEFINE_IDR(i2c_adapter_idr);
63 :
64 : static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
65 :
66 : static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key);
67 : static bool is_registered;
68 :
69 0 : int i2c_transfer_trace_reg(void)
70 : {
71 0 : static_branch_inc(&i2c_trace_msg_key);
72 0 : return 0;
73 : }
74 :
75 0 : void i2c_transfer_trace_unreg(void)
76 : {
77 0 : static_branch_dec(&i2c_trace_msg_key);
78 0 : }
79 :
80 0 : const char *i2c_freq_mode_string(u32 bus_freq_hz)
81 : {
82 0 : switch (bus_freq_hz) {
83 : case I2C_MAX_STANDARD_MODE_FREQ:
84 : return "Standard Mode (100 kHz)";
85 : case I2C_MAX_FAST_MODE_FREQ:
86 0 : return "Fast Mode (400 kHz)";
87 : case I2C_MAX_FAST_MODE_PLUS_FREQ:
88 0 : return "Fast Mode Plus (1.0 MHz)";
89 : case I2C_MAX_TURBO_MODE_FREQ:
90 0 : return "Turbo Mode (1.4 MHz)";
91 : case I2C_MAX_HIGH_SPEED_MODE_FREQ:
92 0 : return "High Speed Mode (3.4 MHz)";
93 : case I2C_MAX_ULTRA_FAST_MODE_FREQ:
94 0 : return "Ultra Fast Mode (5.0 MHz)";
95 : default:
96 0 : return "Unknown Mode";
97 : }
98 : }
99 : EXPORT_SYMBOL_GPL(i2c_freq_mode_string);
100 :
101 0 : const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
102 : const struct i2c_client *client)
103 : {
104 0 : if (!(id && client))
105 : return NULL;
106 :
107 0 : while (id->name[0]) {
108 0 : if (strcmp(client->name, id->name) == 0)
109 : return id;
110 0 : id++;
111 : }
112 : return NULL;
113 : }
114 : EXPORT_SYMBOL_GPL(i2c_match_id);
115 :
116 0 : static int i2c_device_match(struct device *dev, struct device_driver *drv)
117 : {
118 0 : struct i2c_client *client = i2c_verify_client(dev);
119 : struct i2c_driver *driver;
120 :
121 :
122 : /* Attempt an OF style match */
123 0 : if (i2c_of_match_device(drv->of_match_table, client))
124 : return 1;
125 :
126 : /* Then ACPI style match */
127 0 : if (acpi_driver_match_device(dev, drv))
128 : return 1;
129 :
130 0 : driver = to_i2c_driver(drv);
131 :
132 : /* Finally an I2C match */
133 0 : if (i2c_match_id(driver->id_table, client))
134 : return 1;
135 :
136 0 : return 0;
137 : }
138 :
139 0 : static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
140 : {
141 0 : struct i2c_client *client = to_i2c_client(dev);
142 : int rc;
143 :
144 0 : rc = of_device_uevent_modalias(dev, env);
145 : if (rc != -ENODEV)
146 : return rc;
147 :
148 0 : rc = acpi_device_uevent_modalias(dev, env);
149 : if (rc != -ENODEV)
150 : return rc;
151 :
152 0 : return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name);
153 : }
154 :
155 : /* i2c bus recovery routines */
156 0 : static int get_scl_gpio_value(struct i2c_adapter *adap)
157 : {
158 0 : return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod);
159 : }
160 :
161 0 : static void set_scl_gpio_value(struct i2c_adapter *adap, int val)
162 : {
163 0 : gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val);
164 0 : }
165 :
166 0 : static int get_sda_gpio_value(struct i2c_adapter *adap)
167 : {
168 0 : return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod);
169 : }
170 :
171 : static void set_sda_gpio_value(struct i2c_adapter *adap, int val)
172 : {
173 : gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val);
174 : }
175 :
176 0 : static int i2c_generic_bus_free(struct i2c_adapter *adap)
177 : {
178 0 : struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
179 0 : int ret = -EOPNOTSUPP;
180 :
181 0 : if (bri->get_bus_free)
182 0 : ret = bri->get_bus_free(adap);
183 0 : else if (bri->get_sda)
184 0 : ret = bri->get_sda(adap);
185 :
186 0 : if (ret < 0)
187 : return ret;
188 :
189 0 : return ret ? 0 : -EBUSY;
190 : }
191 :
192 : /*
193 : * We are generating clock pulses. ndelay() determines durating of clk pulses.
194 : * We will generate clock with rate 100 KHz and so duration of both clock levels
195 : * is: delay in ns = (10^6 / 100) / 2
196 : */
197 : #define RECOVERY_NDELAY 5000
198 : #define RECOVERY_CLK_CNT 9
199 :
200 0 : int i2c_generic_scl_recovery(struct i2c_adapter *adap)
201 : {
202 0 : struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
203 0 : int i = 0, scl = 1, ret = 0;
204 :
205 0 : if (bri->prepare_recovery)
206 0 : bri->prepare_recovery(adap);
207 0 : if (bri->pinctrl)
208 : pinctrl_select_state(bri->pinctrl, bri->pins_gpio);
209 :
210 : /*
211 : * If we can set SDA, we will always create a STOP to ensure additional
212 : * pulses will do no harm. This is achieved by letting SDA follow SCL
213 : * half a cycle later. Check the 'incomplete_write_byte' fault injector
214 : * for details. Note that we must honour tsu:sto, 4us, but lets use 5us
215 : * here for simplicity.
216 : */
217 0 : bri->set_scl(adap, scl);
218 0 : ndelay(RECOVERY_NDELAY);
219 0 : if (bri->set_sda)
220 0 : bri->set_sda(adap, scl);
221 : ndelay(RECOVERY_NDELAY / 2);
222 :
223 : /*
224 : * By this time SCL is high, as we need to give 9 falling-rising edges
225 : */
226 0 : while (i++ < RECOVERY_CLK_CNT * 2) {
227 0 : if (scl) {
228 : /* SCL shouldn't be low here */
229 0 : if (!bri->get_scl(adap)) {
230 0 : dev_err(&adap->dev,
231 : "SCL is stuck low, exit recovery\n");
232 0 : ret = -EBUSY;
233 0 : break;
234 : }
235 : }
236 :
237 0 : scl = !scl;
238 0 : bri->set_scl(adap, scl);
239 : /* Creating STOP again, see above */
240 0 : if (scl) {
241 : /* Honour minimum tsu:sto */
242 : ndelay(RECOVERY_NDELAY);
243 : } else {
244 : /* Honour minimum tf and thd:dat */
245 : ndelay(RECOVERY_NDELAY / 2);
246 : }
247 0 : if (bri->set_sda)
248 0 : bri->set_sda(adap, scl);
249 0 : ndelay(RECOVERY_NDELAY / 2);
250 :
251 0 : if (scl) {
252 0 : ret = i2c_generic_bus_free(adap);
253 0 : if (ret == 0)
254 : break;
255 : }
256 : }
257 :
258 : /* If we can't check bus status, assume recovery worked */
259 0 : if (ret == -EOPNOTSUPP)
260 0 : ret = 0;
261 :
262 0 : if (bri->unprepare_recovery)
263 0 : bri->unprepare_recovery(adap);
264 0 : if (bri->pinctrl)
265 : pinctrl_select_state(bri->pinctrl, bri->pins_default);
266 :
267 0 : return ret;
268 : }
269 : EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery);
270 :
271 0 : int i2c_recover_bus(struct i2c_adapter *adap)
272 : {
273 0 : if (!adap->bus_recovery_info)
274 : return -EBUSY;
275 :
276 : dev_dbg(&adap->dev, "Trying i2c bus recovery\n");
277 0 : return adap->bus_recovery_info->recover_bus(adap);
278 : }
279 : EXPORT_SYMBOL_GPL(i2c_recover_bus);
280 :
281 0 : static void i2c_gpio_init_pinctrl_recovery(struct i2c_adapter *adap)
282 : {
283 0 : struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
284 0 : struct device *dev = &adap->dev;
285 0 : struct pinctrl *p = bri->pinctrl;
286 :
287 : /*
288 : * we can't change states without pinctrl, so remove the states if
289 : * populated
290 : */
291 0 : if (!p) {
292 0 : bri->pins_default = NULL;
293 0 : bri->pins_gpio = NULL;
294 0 : return;
295 : }
296 :
297 0 : if (!bri->pins_default) {
298 0 : bri->pins_default = pinctrl_lookup_state(p,
299 : PINCTRL_STATE_DEFAULT);
300 0 : if (IS_ERR(bri->pins_default)) {
301 : dev_dbg(dev, PINCTRL_STATE_DEFAULT " state not found for GPIO recovery\n");
302 : bri->pins_default = NULL;
303 : }
304 : }
305 0 : if (!bri->pins_gpio) {
306 0 : bri->pins_gpio = pinctrl_lookup_state(p, "gpio");
307 0 : if (IS_ERR(bri->pins_gpio))
308 : bri->pins_gpio = pinctrl_lookup_state(p, "recovery");
309 :
310 0 : if (IS_ERR(bri->pins_gpio)) {
311 : dev_dbg(dev, "no gpio or recovery state found for GPIO recovery\n");
312 : bri->pins_gpio = NULL;
313 : }
314 : }
315 :
316 : /* for pinctrl state changes, we need all the information */
317 0 : if (bri->pins_default && bri->pins_gpio) {
318 0 : dev_info(dev, "using pinctrl states for GPIO recovery");
319 : } else {
320 0 : bri->pinctrl = NULL;
321 0 : bri->pins_default = NULL;
322 0 : bri->pins_gpio = NULL;
323 : }
324 : }
325 :
326 0 : static int i2c_gpio_init_generic_recovery(struct i2c_adapter *adap)
327 : {
328 0 : struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
329 0 : struct device *dev = &adap->dev;
330 : struct gpio_desc *gpiod;
331 0 : int ret = 0;
332 :
333 : /*
334 : * don't touch the recovery information if the driver is not using
335 : * generic SCL recovery
336 : */
337 0 : if (bri->recover_bus && bri->recover_bus != i2c_generic_scl_recovery)
338 : return 0;
339 :
340 : /*
341 : * pins might be taken as GPIO, so we should inform pinctrl about
342 : * this and move the state to GPIO
343 : */
344 0 : if (bri->pinctrl)
345 : pinctrl_select_state(bri->pinctrl, bri->pins_gpio);
346 :
347 : /*
348 : * if there is incomplete or no recovery information, see if generic
349 : * GPIO recovery is available
350 : */
351 0 : if (!bri->scl_gpiod) {
352 : gpiod = devm_gpiod_get(dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN);
353 : if (PTR_ERR(gpiod) == -EPROBE_DEFER) {
354 : ret = -EPROBE_DEFER;
355 : goto cleanup_pinctrl_state;
356 : }
357 : if (!IS_ERR(gpiod)) {
358 : bri->scl_gpiod = gpiod;
359 : bri->recover_bus = i2c_generic_scl_recovery;
360 : dev_info(dev, "using generic GPIOs for recovery\n");
361 : }
362 : }
363 :
364 : /* SDA GPIOD line is optional, so we care about DEFER only */
365 0 : if (!bri->sda_gpiod) {
366 : /*
367 : * We have SCL. Pull SCL low and wait a bit so that SDA glitches
368 : * have no effect.
369 : */
370 0 : gpiod_direction_output(bri->scl_gpiod, 0);
371 0 : udelay(10);
372 0 : gpiod = devm_gpiod_get(dev, "sda", GPIOD_IN);
373 :
374 : /* Wait a bit in case of a SDA glitch, and then release SCL. */
375 0 : udelay(10);
376 0 : gpiod_direction_output(bri->scl_gpiod, 1);
377 :
378 : if (PTR_ERR(gpiod) == -EPROBE_DEFER) {
379 : ret = -EPROBE_DEFER;
380 : goto cleanup_pinctrl_state;
381 : }
382 : if (!IS_ERR(gpiod))
383 : bri->sda_gpiod = gpiod;
384 : }
385 :
386 : cleanup_pinctrl_state:
387 : /* change the state of the pins back to their default state */
388 0 : if (bri->pinctrl)
389 : pinctrl_select_state(bri->pinctrl, bri->pins_default);
390 :
391 : return ret;
392 : }
393 :
394 : static int i2c_gpio_init_recovery(struct i2c_adapter *adap)
395 : {
396 0 : i2c_gpio_init_pinctrl_recovery(adap);
397 0 : return i2c_gpio_init_generic_recovery(adap);
398 : }
399 :
400 0 : static int i2c_init_recovery(struct i2c_adapter *adap)
401 : {
402 0 : struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
403 0 : bool is_error_level = true;
404 : char *err_str;
405 :
406 0 : if (!bri)
407 : return 0;
408 :
409 0 : if (i2c_gpio_init_recovery(adap) == -EPROBE_DEFER)
410 : return -EPROBE_DEFER;
411 :
412 0 : if (!bri->recover_bus) {
413 : err_str = "no suitable method provided";
414 : is_error_level = false;
415 : goto err;
416 : }
417 :
418 0 : if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) {
419 0 : bri->get_scl = get_scl_gpio_value;
420 0 : bri->set_scl = set_scl_gpio_value;
421 0 : if (bri->sda_gpiod) {
422 0 : bri->get_sda = get_sda_gpio_value;
423 : /* FIXME: add proper flag instead of '0' once available */
424 0 : if (gpiod_get_direction(bri->sda_gpiod) == 0)
425 : bri->set_sda = set_sda_gpio_value;
426 : }
427 0 : } else if (bri->recover_bus == i2c_generic_scl_recovery) {
428 : /* Generic SCL recovery */
429 0 : if (!bri->set_scl || !bri->get_scl) {
430 : err_str = "no {get|set}_scl() found";
431 : goto err;
432 : }
433 0 : if (!bri->set_sda && !bri->get_sda) {
434 : err_str = "either get_sda() or set_sda() needed";
435 : goto err;
436 : }
437 : }
438 :
439 : return 0;
440 : err:
441 0 : if (is_error_level)
442 0 : dev_err(&adap->dev, "Not using recovery: %s\n", err_str);
443 : else
444 : dev_dbg(&adap->dev, "Not using recovery: %s\n", err_str);
445 0 : adap->bus_recovery_info = NULL;
446 :
447 0 : return -EINVAL;
448 : }
449 :
450 0 : static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client)
451 : {
452 0 : struct i2c_adapter *adap = client->adapter;
453 : unsigned int irq;
454 :
455 0 : if (!adap->host_notify_domain)
456 : return -ENXIO;
457 :
458 0 : if (client->flags & I2C_CLIENT_TEN)
459 : return -EINVAL;
460 :
461 0 : irq = irq_create_mapping(adap->host_notify_domain, client->addr);
462 :
463 0 : return irq > 0 ? irq : -ENXIO;
464 : }
465 :
466 0 : static int i2c_device_probe(struct device *dev)
467 : {
468 0 : struct i2c_client *client = i2c_verify_client(dev);
469 : struct i2c_driver *driver;
470 : int status;
471 :
472 0 : if (!client)
473 : return 0;
474 :
475 0 : client->irq = client->init_irq;
476 :
477 0 : if (!client->irq) {
478 0 : int irq = -ENOENT;
479 :
480 0 : if (client->flags & I2C_CLIENT_HOST_NOTIFY) {
481 : dev_dbg(dev, "Using Host Notify IRQ\n");
482 : /* Keep adapter active when Host Notify is required */
483 0 : pm_runtime_get_sync(&client->adapter->dev);
484 0 : irq = i2c_smbus_host_notify_to_irq(client);
485 0 : } else if (dev->of_node) {
486 0 : irq = of_irq_get_byname(dev->of_node, "irq");
487 : if (irq == -EINVAL || irq == -ENODATA)
488 : irq = of_irq_get(dev->of_node, 0);
489 : } else if (ACPI_COMPANION(dev)) {
490 : irq = i2c_acpi_get_irq(client);
491 : }
492 0 : if (irq == -EPROBE_DEFER) {
493 : status = irq;
494 : goto put_sync_adapter;
495 : }
496 :
497 0 : if (irq < 0)
498 0 : irq = 0;
499 :
500 0 : client->irq = irq;
501 : }
502 :
503 0 : driver = to_i2c_driver(dev->driver);
504 :
505 : /*
506 : * An I2C ID table is not mandatory, if and only if, a suitable OF
507 : * or ACPI ID table is supplied for the probing device.
508 : */
509 0 : if (!driver->id_table &&
510 : !acpi_driver_match_device(dev, dev->driver) &&
511 : !i2c_of_match_device(dev->driver->of_match_table, client)) {
512 : status = -ENODEV;
513 : goto put_sync_adapter;
514 : }
515 :
516 0 : if (client->flags & I2C_CLIENT_WAKE) {
517 : int wakeirq;
518 :
519 0 : wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
520 : if (wakeirq == -EPROBE_DEFER) {
521 : status = wakeirq;
522 : goto put_sync_adapter;
523 : }
524 :
525 0 : device_init_wakeup(&client->dev, true);
526 :
527 : if (wakeirq > 0 && wakeirq != client->irq)
528 : status = dev_pm_set_dedicated_wake_irq(dev, wakeirq);
529 0 : else if (client->irq > 0)
530 0 : status = dev_pm_set_wake_irq(dev, client->irq);
531 : else
532 : status = 0;
533 :
534 0 : if (status)
535 0 : dev_warn(&client->dev, "failed to set up wakeup irq\n");
536 : }
537 :
538 : dev_dbg(dev, "probe\n");
539 :
540 0 : status = of_clk_set_defaults(dev->of_node, false);
541 : if (status < 0)
542 : goto err_clear_wakeup_irq;
543 :
544 0 : status = dev_pm_domain_attach(&client->dev,
545 0 : !i2c_acpi_waive_d0_probe(dev));
546 0 : if (status)
547 : goto err_clear_wakeup_irq;
548 :
549 0 : client->devres_group_id = devres_open_group(&client->dev, NULL,
550 : GFP_KERNEL);
551 0 : if (!client->devres_group_id) {
552 : status = -ENOMEM;
553 : goto err_detach_pm_domain;
554 : }
555 :
556 : /*
557 : * When there are no more users of probe(),
558 : * rename probe_new to probe.
559 : */
560 0 : if (driver->probe_new)
561 0 : status = driver->probe_new(client);
562 0 : else if (driver->probe)
563 0 : status = driver->probe(client,
564 : i2c_match_id(driver->id_table, client));
565 : else
566 : status = -EINVAL;
567 :
568 : /*
569 : * Note that we are not closing the devres group opened above so
570 : * even resources that were attached to the device after probe is
571 : * run are released when i2c_device_remove() is executed. This is
572 : * needed as some drivers would allocate additional resources,
573 : * for example when updating firmware.
574 : */
575 :
576 0 : if (status)
577 : goto err_release_driver_resources;
578 :
579 : return 0;
580 :
581 : err_release_driver_resources:
582 0 : devres_release_group(&client->dev, client->devres_group_id);
583 : err_detach_pm_domain:
584 0 : dev_pm_domain_detach(&client->dev, !i2c_acpi_waive_d0_probe(dev));
585 : err_clear_wakeup_irq:
586 0 : dev_pm_clear_wake_irq(&client->dev);
587 0 : device_init_wakeup(&client->dev, false);
588 : put_sync_adapter:
589 0 : if (client->flags & I2C_CLIENT_HOST_NOTIFY)
590 0 : pm_runtime_put_sync(&client->adapter->dev);
591 :
592 : return status;
593 : }
594 :
595 0 : static void i2c_device_remove(struct device *dev)
596 : {
597 0 : struct i2c_client *client = to_i2c_client(dev);
598 : struct i2c_driver *driver;
599 :
600 0 : driver = to_i2c_driver(dev->driver);
601 0 : if (driver->remove) {
602 : int status;
603 :
604 : dev_dbg(dev, "remove\n");
605 :
606 0 : status = driver->remove(client);
607 0 : if (status)
608 0 : dev_warn(dev, "remove failed (%pe), will be ignored\n", ERR_PTR(status));
609 : }
610 :
611 0 : devres_release_group(&client->dev, client->devres_group_id);
612 :
613 0 : dev_pm_domain_detach(&client->dev, !i2c_acpi_waive_d0_probe(dev));
614 :
615 0 : dev_pm_clear_wake_irq(&client->dev);
616 0 : device_init_wakeup(&client->dev, false);
617 :
618 0 : client->irq = 0;
619 0 : if (client->flags & I2C_CLIENT_HOST_NOTIFY)
620 0 : pm_runtime_put(&client->adapter->dev);
621 0 : }
622 :
623 0 : static void i2c_device_shutdown(struct device *dev)
624 : {
625 0 : struct i2c_client *client = i2c_verify_client(dev);
626 : struct i2c_driver *driver;
627 :
628 0 : if (!client || !dev->driver)
629 : return;
630 0 : driver = to_i2c_driver(dev->driver);
631 0 : if (driver->shutdown)
632 0 : driver->shutdown(client);
633 0 : else if (client->irq > 0)
634 0 : disable_irq(client->irq);
635 : }
636 :
637 0 : static void i2c_client_dev_release(struct device *dev)
638 : {
639 0 : kfree(to_i2c_client(dev));
640 0 : }
641 :
642 : static ssize_t
643 0 : name_show(struct device *dev, struct device_attribute *attr, char *buf)
644 : {
645 0 : return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?
646 0 : to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);
647 : }
648 : static DEVICE_ATTR_RO(name);
649 :
650 : static ssize_t
651 0 : modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
652 : {
653 0 : struct i2c_client *client = to_i2c_client(dev);
654 : int len;
655 :
656 0 : len = of_device_modalias(dev, buf, PAGE_SIZE);
657 : if (len != -ENODEV)
658 : return len;
659 :
660 0 : len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
661 : if (len != -ENODEV)
662 : return len;
663 :
664 0 : return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
665 : }
666 : static DEVICE_ATTR_RO(modalias);
667 :
668 : static struct attribute *i2c_dev_attrs[] = {
669 : &dev_attr_name.attr,
670 : /* modalias helps coldplug: modprobe $(cat .../modalias) */
671 : &dev_attr_modalias.attr,
672 : NULL
673 : };
674 : ATTRIBUTE_GROUPS(i2c_dev);
675 :
676 : struct bus_type i2c_bus_type = {
677 : .name = "i2c",
678 : .match = i2c_device_match,
679 : .probe = i2c_device_probe,
680 : .remove = i2c_device_remove,
681 : .shutdown = i2c_device_shutdown,
682 : };
683 : EXPORT_SYMBOL_GPL(i2c_bus_type);
684 :
685 : struct device_type i2c_client_type = {
686 : .groups = i2c_dev_groups,
687 : .uevent = i2c_device_uevent,
688 : .release = i2c_client_dev_release,
689 : };
690 : EXPORT_SYMBOL_GPL(i2c_client_type);
691 :
692 :
693 : /**
694 : * i2c_verify_client - return parameter as i2c_client, or NULL
695 : * @dev: device, probably from some driver model iterator
696 : *
697 : * When traversing the driver model tree, perhaps using driver model
698 : * iterators like @device_for_each_child(), you can't assume very much
699 : * about the nodes you find. Use this function to avoid oopses caused
700 : * by wrongly treating some non-I2C device as an i2c_client.
701 : */
702 0 : struct i2c_client *i2c_verify_client(struct device *dev)
703 : {
704 0 : return (dev->type == &i2c_client_type)
705 0 : ? to_i2c_client(dev)
706 0 : : NULL;
707 : }
708 : EXPORT_SYMBOL(i2c_verify_client);
709 :
710 :
711 : /* Return a unique address which takes the flags of the client into account */
712 : static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client)
713 : {
714 0 : unsigned short addr = client->addr;
715 :
716 : /* For some client flags, add an arbitrary offset to avoid collisions */
717 0 : if (client->flags & I2C_CLIENT_TEN)
718 0 : addr |= I2C_ADDR_OFFSET_TEN_BIT;
719 :
720 0 : if (client->flags & I2C_CLIENT_SLAVE)
721 0 : addr |= I2C_ADDR_OFFSET_SLAVE;
722 :
723 : return addr;
724 : }
725 :
726 : /* This is a permissive address validity check, I2C address map constraints
727 : * are purposely not enforced, except for the general call address. */
728 : static int i2c_check_addr_validity(unsigned int addr, unsigned short flags)
729 : {
730 0 : if (flags & I2C_CLIENT_TEN) {
731 : /* 10-bit address, all values are valid */
732 0 : if (addr > 0x3ff)
733 : return -EINVAL;
734 : } else {
735 : /* 7-bit address, reject the general call address */
736 0 : if (addr == 0x00 || addr > 0x7f)
737 : return -EINVAL;
738 : }
739 : return 0;
740 : }
741 :
742 : /* And this is a strict address validity check, used when probing. If a
743 : * device uses a reserved address, then it shouldn't be probed. 7-bit
744 : * addressing is assumed, 10-bit address devices are rare and should be
745 : * explicitly enumerated. */
746 0 : int i2c_check_7bit_addr_validity_strict(unsigned short addr)
747 : {
748 : /*
749 : * Reserved addresses per I2C specification:
750 : * 0x00 General call address / START byte
751 : * 0x01 CBUS address
752 : * 0x02 Reserved for different bus format
753 : * 0x03 Reserved for future purposes
754 : * 0x04-0x07 Hs-mode master code
755 : * 0x78-0x7b 10-bit slave addressing
756 : * 0x7c-0x7f Reserved for future purposes
757 : */
758 0 : if (addr < 0x08 || addr > 0x77)
759 : return -EINVAL;
760 0 : return 0;
761 : }
762 :
763 : static int __i2c_check_addr_busy(struct device *dev, void *addrp)
764 : {
765 0 : struct i2c_client *client = i2c_verify_client(dev);
766 0 : int addr = *(int *)addrp;
767 :
768 0 : if (client && i2c_encode_flags_to_addr(client) == addr)
769 : return -EBUSY;
770 : return 0;
771 : }
772 :
773 : /* walk up mux tree */
774 : static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)
775 : {
776 : struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
777 : int result;
778 :
779 : result = device_for_each_child(&adapter->dev, &addr,
780 : __i2c_check_addr_busy);
781 :
782 : if (!result && parent)
783 : result = i2c_check_mux_parents(parent, addr);
784 :
785 : return result;
786 : }
787 :
788 : /* recurse down mux tree */
789 0 : static int i2c_check_mux_children(struct device *dev, void *addrp)
790 : {
791 : int result;
792 :
793 0 : if (dev->type == &i2c_adapter_type)
794 0 : result = device_for_each_child(dev, addrp,
795 : i2c_check_mux_children);
796 : else
797 : result = __i2c_check_addr_busy(dev, addrp);
798 :
799 0 : return result;
800 : }
801 :
802 : static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
803 : {
804 0 : struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
805 0 : int result = 0;
806 :
807 : if (parent)
808 : result = i2c_check_mux_parents(parent, addr);
809 :
810 : if (!result)
811 0 : result = device_for_each_child(&adapter->dev, &addr,
812 : i2c_check_mux_children);
813 :
814 : return result;
815 : }
816 :
817 : /**
818 : * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment
819 : * @adapter: Target I2C bus segment
820 : * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
821 : * locks only this branch in the adapter tree
822 : */
823 0 : static void i2c_adapter_lock_bus(struct i2c_adapter *adapter,
824 : unsigned int flags)
825 : {
826 0 : rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter));
827 0 : }
828 :
829 : /**
830 : * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment
831 : * @adapter: Target I2C bus segment
832 : * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT
833 : * trylocks only this branch in the adapter tree
834 : */
835 0 : static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter,
836 : unsigned int flags)
837 : {
838 0 : return rt_mutex_trylock(&adapter->bus_lock);
839 : }
840 :
841 : /**
842 : * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment
843 : * @adapter: Target I2C bus segment
844 : * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
845 : * unlocks only this branch in the adapter tree
846 : */
847 0 : static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter,
848 : unsigned int flags)
849 : {
850 0 : rt_mutex_unlock(&adapter->bus_lock);
851 0 : }
852 :
853 0 : static void i2c_dev_set_name(struct i2c_adapter *adap,
854 : struct i2c_client *client,
855 : struct i2c_board_info const *info)
856 : {
857 0 : struct acpi_device *adev = ACPI_COMPANION(&client->dev);
858 :
859 0 : if (info && info->dev_name) {
860 0 : dev_set_name(&client->dev, "i2c-%s", info->dev_name);
861 0 : return;
862 : }
863 :
864 : if (adev) {
865 : dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev));
866 : return;
867 : }
868 :
869 0 : dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
870 0 : i2c_encode_flags_to_addr(client));
871 : }
872 :
873 0 : int i2c_dev_irq_from_resources(const struct resource *resources,
874 : unsigned int num_resources)
875 : {
876 : struct irq_data *irqd;
877 : int i;
878 :
879 0 : for (i = 0; i < num_resources; i++) {
880 0 : const struct resource *r = &resources[i];
881 :
882 0 : if (resource_type(r) != IORESOURCE_IRQ)
883 0 : continue;
884 :
885 0 : if (r->flags & IORESOURCE_BITS) {
886 0 : irqd = irq_get_irq_data(r->start);
887 0 : if (!irqd)
888 : break;
889 :
890 0 : irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
891 : }
892 :
893 0 : return r->start;
894 : }
895 :
896 : return 0;
897 : }
898 :
899 : /**
900 : * i2c_new_client_device - instantiate an i2c device
901 : * @adap: the adapter managing the device
902 : * @info: describes one I2C device; bus_num is ignored
903 : * Context: can sleep
904 : *
905 : * Create an i2c device. Binding is handled through driver model
906 : * probe()/remove() methods. A driver may be bound to this device when we
907 : * return from this function, or any later moment (e.g. maybe hotplugging will
908 : * load the driver module). This call is not appropriate for use by mainboard
909 : * initialization logic, which usually runs during an arch_initcall() long
910 : * before any i2c_adapter could exist.
911 : *
912 : * This returns the new i2c client, which may be saved for later use with
913 : * i2c_unregister_device(); or an ERR_PTR to describe the error.
914 : */
915 : struct i2c_client *
916 0 : i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
917 : {
918 : struct i2c_client *client;
919 : int status;
920 :
921 0 : client = kzalloc(sizeof *client, GFP_KERNEL);
922 0 : if (!client)
923 : return ERR_PTR(-ENOMEM);
924 :
925 0 : client->adapter = adap;
926 :
927 0 : client->dev.platform_data = info->platform_data;
928 0 : client->flags = info->flags;
929 0 : client->addr = info->addr;
930 :
931 0 : client->init_irq = info->irq;
932 0 : if (!client->init_irq)
933 0 : client->init_irq = i2c_dev_irq_from_resources(info->resources,
934 : info->num_resources);
935 :
936 0 : strlcpy(client->name, info->type, sizeof(client->name));
937 :
938 0 : status = i2c_check_addr_validity(client->addr, client->flags);
939 0 : if (status) {
940 0 : dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n",
941 : client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr);
942 0 : goto out_err_silent;
943 : }
944 :
945 : /* Check for address business */
946 0 : status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client));
947 0 : if (status)
948 : goto out_err;
949 :
950 0 : client->dev.parent = &client->adapter->dev;
951 0 : client->dev.bus = &i2c_bus_type;
952 0 : client->dev.type = &i2c_client_type;
953 0 : client->dev.of_node = of_node_get(info->of_node);
954 0 : client->dev.fwnode = info->fwnode;
955 :
956 0 : device_enable_async_suspend(&client->dev);
957 0 : i2c_dev_set_name(adap, client, info);
958 :
959 0 : if (info->swnode) {
960 0 : status = device_add_software_node(&client->dev, info->swnode);
961 0 : if (status) {
962 0 : dev_err(&adap->dev,
963 : "Failed to add software node to client %s: %d\n",
964 : client->name, status);
965 0 : goto out_err_put_of_node;
966 : }
967 : }
968 :
969 0 : status = device_register(&client->dev);
970 0 : if (status)
971 : goto out_remove_swnode;
972 :
973 : dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
974 : client->name, dev_name(&client->dev));
975 :
976 : return client;
977 :
978 : out_remove_swnode:
979 0 : device_remove_software_node(&client->dev);
980 : out_err_put_of_node:
981 0 : of_node_put(info->of_node);
982 : out_err:
983 0 : dev_err(&adap->dev,
984 : "Failed to register i2c client %s at 0x%02x (%d)\n",
985 : client->name, client->addr, status);
986 : out_err_silent:
987 0 : kfree(client);
988 0 : return ERR_PTR(status);
989 : }
990 : EXPORT_SYMBOL_GPL(i2c_new_client_device);
991 :
992 : /**
993 : * i2c_unregister_device - reverse effect of i2c_new_*_device()
994 : * @client: value returned from i2c_new_*_device()
995 : * Context: can sleep
996 : */
997 0 : void i2c_unregister_device(struct i2c_client *client)
998 : {
999 0 : if (IS_ERR_OR_NULL(client))
1000 : return;
1001 :
1002 : if (client->dev.of_node) {
1003 : of_node_clear_flag(client->dev.of_node, OF_POPULATED);
1004 : of_node_put(client->dev.of_node);
1005 : }
1006 :
1007 : if (ACPI_COMPANION(&client->dev))
1008 : acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev));
1009 0 : device_remove_software_node(&client->dev);
1010 0 : device_unregister(&client->dev);
1011 : }
1012 : EXPORT_SYMBOL_GPL(i2c_unregister_device);
1013 :
1014 :
1015 : static const struct i2c_device_id dummy_id[] = {
1016 : { "dummy", 0 },
1017 : { },
1018 : };
1019 :
1020 0 : static int dummy_probe(struct i2c_client *client,
1021 : const struct i2c_device_id *id)
1022 : {
1023 0 : return 0;
1024 : }
1025 :
1026 0 : static int dummy_remove(struct i2c_client *client)
1027 : {
1028 0 : return 0;
1029 : }
1030 :
1031 : static struct i2c_driver dummy_driver = {
1032 : .driver.name = "dummy",
1033 : .probe = dummy_probe,
1034 : .remove = dummy_remove,
1035 : .id_table = dummy_id,
1036 : };
1037 :
1038 : /**
1039 : * i2c_new_dummy_device - return a new i2c device bound to a dummy driver
1040 : * @adapter: the adapter managing the device
1041 : * @address: seven bit address to be used
1042 : * Context: can sleep
1043 : *
1044 : * This returns an I2C client bound to the "dummy" driver, intended for use
1045 : * with devices that consume multiple addresses. Examples of such chips
1046 : * include various EEPROMS (like 24c04 and 24c08 models).
1047 : *
1048 : * These dummy devices have two main uses. First, most I2C and SMBus calls
1049 : * except i2c_transfer() need a client handle; the dummy will be that handle.
1050 : * And second, this prevents the specified address from being bound to a
1051 : * different driver.
1052 : *
1053 : * This returns the new i2c client, which should be saved for later use with
1054 : * i2c_unregister_device(); or an ERR_PTR to describe the error.
1055 : */
1056 0 : struct i2c_client *i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address)
1057 : {
1058 0 : struct i2c_board_info info = {
1059 : I2C_BOARD_INFO("dummy", address),
1060 : };
1061 :
1062 0 : return i2c_new_client_device(adapter, &info);
1063 : }
1064 : EXPORT_SYMBOL_GPL(i2c_new_dummy_device);
1065 :
1066 0 : static void devm_i2c_release_dummy(void *client)
1067 : {
1068 0 : i2c_unregister_device(client);
1069 0 : }
1070 :
1071 : /**
1072 : * devm_i2c_new_dummy_device - return a new i2c device bound to a dummy driver
1073 : * @dev: device the managed resource is bound to
1074 : * @adapter: the adapter managing the device
1075 : * @address: seven bit address to be used
1076 : * Context: can sleep
1077 : *
1078 : * This is the device-managed version of @i2c_new_dummy_device. It returns the
1079 : * new i2c client or an ERR_PTR in case of an error.
1080 : */
1081 0 : struct i2c_client *devm_i2c_new_dummy_device(struct device *dev,
1082 : struct i2c_adapter *adapter,
1083 : u16 address)
1084 : {
1085 : struct i2c_client *client;
1086 : int ret;
1087 :
1088 0 : client = i2c_new_dummy_device(adapter, address);
1089 0 : if (IS_ERR(client))
1090 : return client;
1091 :
1092 0 : ret = devm_add_action_or_reset(dev, devm_i2c_release_dummy, client);
1093 0 : if (ret)
1094 0 : return ERR_PTR(ret);
1095 :
1096 : return client;
1097 : }
1098 : EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device);
1099 :
1100 : /**
1101 : * i2c_new_ancillary_device - Helper to get the instantiated secondary address
1102 : * and create the associated device
1103 : * @client: Handle to the primary client
1104 : * @name: Handle to specify which secondary address to get
1105 : * @default_addr: Used as a fallback if no secondary address was specified
1106 : * Context: can sleep
1107 : *
1108 : * I2C clients can be composed of multiple I2C slaves bound together in a single
1109 : * component. The I2C client driver then binds to the master I2C slave and needs
1110 : * to create I2C dummy clients to communicate with all the other slaves.
1111 : *
1112 : * This function creates and returns an I2C dummy client whose I2C address is
1113 : * retrieved from the platform firmware based on the given slave name. If no
1114 : * address is specified by the firmware default_addr is used.
1115 : *
1116 : * On DT-based platforms the address is retrieved from the "reg" property entry
1117 : * cell whose "reg-names" value matches the slave name.
1118 : *
1119 : * This returns the new i2c client, which should be saved for later use with
1120 : * i2c_unregister_device(); or an ERR_PTR to describe the error.
1121 : */
1122 0 : struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client,
1123 : const char *name,
1124 : u16 default_addr)
1125 : {
1126 0 : struct device_node *np = client->dev.of_node;
1127 0 : u32 addr = default_addr;
1128 : int i;
1129 :
1130 : if (np) {
1131 : i = of_property_match_string(np, "reg-names", name);
1132 : if (i >= 0)
1133 : of_property_read_u32_index(np, "reg", i, &addr);
1134 : }
1135 :
1136 : dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr);
1137 0 : return i2c_new_dummy_device(client->adapter, addr);
1138 : }
1139 : EXPORT_SYMBOL_GPL(i2c_new_ancillary_device);
1140 :
1141 : /* ------------------------------------------------------------------------- */
1142 :
1143 : /* I2C bus adapters -- one roots each I2C or SMBUS segment */
1144 :
1145 0 : static void i2c_adapter_dev_release(struct device *dev)
1146 : {
1147 0 : struct i2c_adapter *adap = to_i2c_adapter(dev);
1148 0 : complete(&adap->dev_released);
1149 0 : }
1150 :
1151 0 : unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
1152 : {
1153 0 : unsigned int depth = 0;
1154 :
1155 0 : while ((adapter = i2c_parent_is_i2c_adapter(adapter)))
1156 : depth++;
1157 :
1158 0 : WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES,
1159 : "adapter depth exceeds lockdep subclass limit\n");
1160 :
1161 0 : return depth;
1162 : }
1163 : EXPORT_SYMBOL_GPL(i2c_adapter_depth);
1164 :
1165 : /*
1166 : * Let users instantiate I2C devices through sysfs. This can be used when
1167 : * platform initialization code doesn't contain the proper data for
1168 : * whatever reason. Also useful for drivers that do device detection and
1169 : * detection fails, either because the device uses an unexpected address,
1170 : * or this is a compatible device with different ID register values.
1171 : *
1172 : * Parameter checking may look overzealous, but we really don't want
1173 : * the user to provide incorrect parameters.
1174 : */
1175 : static ssize_t
1176 0 : new_device_store(struct device *dev, struct device_attribute *attr,
1177 : const char *buf, size_t count)
1178 : {
1179 0 : struct i2c_adapter *adap = to_i2c_adapter(dev);
1180 : struct i2c_board_info info;
1181 : struct i2c_client *client;
1182 : char *blank, end;
1183 : int res;
1184 :
1185 0 : memset(&info, 0, sizeof(struct i2c_board_info));
1186 :
1187 0 : blank = strchr(buf, ' ');
1188 0 : if (!blank) {
1189 0 : dev_err(dev, "%s: Missing parameters\n", "new_device");
1190 0 : return -EINVAL;
1191 : }
1192 0 : if (blank - buf > I2C_NAME_SIZE - 1) {
1193 0 : dev_err(dev, "%s: Invalid device name\n", "new_device");
1194 0 : return -EINVAL;
1195 : }
1196 0 : memcpy(info.type, buf, blank - buf);
1197 :
1198 : /* Parse remaining parameters, reject extra parameters */
1199 0 : res = sscanf(++blank, "%hi%c", &info.addr, &end);
1200 0 : if (res < 1) {
1201 0 : dev_err(dev, "%s: Can't parse I2C address\n", "new_device");
1202 0 : return -EINVAL;
1203 : }
1204 0 : if (res > 1 && end != '\n') {
1205 0 : dev_err(dev, "%s: Extra parameters\n", "new_device");
1206 0 : return -EINVAL;
1207 : }
1208 :
1209 0 : if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) {
1210 0 : info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT;
1211 0 : info.flags |= I2C_CLIENT_TEN;
1212 : }
1213 :
1214 0 : if (info.addr & I2C_ADDR_OFFSET_SLAVE) {
1215 0 : info.addr &= ~I2C_ADDR_OFFSET_SLAVE;
1216 0 : info.flags |= I2C_CLIENT_SLAVE;
1217 : }
1218 :
1219 0 : client = i2c_new_client_device(adap, &info);
1220 0 : if (IS_ERR(client))
1221 0 : return PTR_ERR(client);
1222 :
1223 : /* Keep track of the added device */
1224 0 : mutex_lock(&adap->userspace_clients_lock);
1225 0 : list_add_tail(&client->detected, &adap->userspace_clients);
1226 0 : mutex_unlock(&adap->userspace_clients_lock);
1227 0 : dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
1228 : info.type, info.addr);
1229 :
1230 0 : return count;
1231 : }
1232 : static DEVICE_ATTR_WO(new_device);
1233 :
1234 : /*
1235 : * And of course let the users delete the devices they instantiated, if
1236 : * they got it wrong. This interface can only be used to delete devices
1237 : * instantiated by i2c_sysfs_new_device above. This guarantees that we
1238 : * don't delete devices to which some kernel code still has references.
1239 : *
1240 : * Parameter checking may look overzealous, but we really don't want
1241 : * the user to delete the wrong device.
1242 : */
1243 : static ssize_t
1244 0 : delete_device_store(struct device *dev, struct device_attribute *attr,
1245 : const char *buf, size_t count)
1246 : {
1247 0 : struct i2c_adapter *adap = to_i2c_adapter(dev);
1248 : struct i2c_client *client, *next;
1249 : unsigned short addr;
1250 : char end;
1251 : int res;
1252 :
1253 : /* Parse parameters, reject extra parameters */
1254 0 : res = sscanf(buf, "%hi%c", &addr, &end);
1255 0 : if (res < 1) {
1256 0 : dev_err(dev, "%s: Can't parse I2C address\n", "delete_device");
1257 0 : return -EINVAL;
1258 : }
1259 0 : if (res > 1 && end != '\n') {
1260 0 : dev_err(dev, "%s: Extra parameters\n", "delete_device");
1261 0 : return -EINVAL;
1262 : }
1263 :
1264 : /* Make sure the device was added through sysfs */
1265 0 : res = -ENOENT;
1266 0 : mutex_lock_nested(&adap->userspace_clients_lock,
1267 : i2c_adapter_depth(adap));
1268 0 : list_for_each_entry_safe(client, next, &adap->userspace_clients,
1269 : detected) {
1270 0 : if (i2c_encode_flags_to_addr(client) == addr) {
1271 0 : dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",
1272 : "delete_device", client->name, client->addr);
1273 :
1274 0 : list_del(&client->detected);
1275 0 : i2c_unregister_device(client);
1276 0 : res = count;
1277 0 : break;
1278 : }
1279 : }
1280 0 : mutex_unlock(&adap->userspace_clients_lock);
1281 :
1282 0 : if (res < 0)
1283 0 : dev_err(dev, "%s: Can't find device in list\n",
1284 : "delete_device");
1285 0 : return res;
1286 : }
1287 : static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL,
1288 : delete_device_store);
1289 :
1290 : static struct attribute *i2c_adapter_attrs[] = {
1291 : &dev_attr_name.attr,
1292 : &dev_attr_new_device.attr,
1293 : &dev_attr_delete_device.attr,
1294 : NULL
1295 : };
1296 : ATTRIBUTE_GROUPS(i2c_adapter);
1297 :
1298 : struct device_type i2c_adapter_type = {
1299 : .groups = i2c_adapter_groups,
1300 : .release = i2c_adapter_dev_release,
1301 : };
1302 : EXPORT_SYMBOL_GPL(i2c_adapter_type);
1303 :
1304 : /**
1305 : * i2c_verify_adapter - return parameter as i2c_adapter or NULL
1306 : * @dev: device, probably from some driver model iterator
1307 : *
1308 : * When traversing the driver model tree, perhaps using driver model
1309 : * iterators like @device_for_each_child(), you can't assume very much
1310 : * about the nodes you find. Use this function to avoid oopses caused
1311 : * by wrongly treating some non-I2C device as an i2c_adapter.
1312 : */
1313 0 : struct i2c_adapter *i2c_verify_adapter(struct device *dev)
1314 : {
1315 0 : return (dev->type == &i2c_adapter_type)
1316 0 : ? to_i2c_adapter(dev)
1317 0 : : NULL;
1318 : }
1319 : EXPORT_SYMBOL(i2c_verify_adapter);
1320 :
1321 : #ifdef CONFIG_I2C_COMPAT
1322 : static struct class_compat *i2c_adapter_compat_class;
1323 : #endif
1324 :
1325 0 : static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
1326 : {
1327 : struct i2c_devinfo *devinfo;
1328 :
1329 0 : down_read(&__i2c_board_lock);
1330 0 : list_for_each_entry(devinfo, &__i2c_board_list, list) {
1331 0 : if (devinfo->busnum == adapter->nr &&
1332 0 : IS_ERR(i2c_new_client_device(adapter, &devinfo->board_info)))
1333 0 : dev_err(&adapter->dev,
1334 : "Can't create device at 0x%02x\n",
1335 : devinfo->board_info.addr);
1336 : }
1337 0 : up_read(&__i2c_board_lock);
1338 0 : }
1339 :
1340 : static int i2c_do_add_adapter(struct i2c_driver *driver,
1341 : struct i2c_adapter *adap)
1342 : {
1343 : /* Detect supported devices on that bus, and instantiate them */
1344 0 : i2c_detect(adap, driver);
1345 :
1346 : return 0;
1347 : }
1348 :
1349 0 : static int __process_new_adapter(struct device_driver *d, void *data)
1350 : {
1351 0 : return i2c_do_add_adapter(to_i2c_driver(d), data);
1352 : }
1353 :
1354 : static const struct i2c_lock_operations i2c_adapter_lock_ops = {
1355 : .lock_bus = i2c_adapter_lock_bus,
1356 : .trylock_bus = i2c_adapter_trylock_bus,
1357 : .unlock_bus = i2c_adapter_unlock_bus,
1358 : };
1359 :
1360 0 : static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap)
1361 : {
1362 0 : struct irq_domain *domain = adap->host_notify_domain;
1363 : irq_hw_number_t hwirq;
1364 :
1365 0 : if (!domain)
1366 : return;
1367 :
1368 0 : for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++)
1369 0 : irq_dispose_mapping(irq_find_mapping(domain, hwirq));
1370 :
1371 0 : irq_domain_remove(domain);
1372 0 : adap->host_notify_domain = NULL;
1373 : }
1374 :
1375 0 : static int i2c_host_notify_irq_map(struct irq_domain *h,
1376 : unsigned int virq,
1377 : irq_hw_number_t hw_irq_num)
1378 : {
1379 0 : irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
1380 :
1381 0 : return 0;
1382 : }
1383 :
1384 : static const struct irq_domain_ops i2c_host_notify_irq_ops = {
1385 : .map = i2c_host_notify_irq_map,
1386 : };
1387 :
1388 0 : static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap)
1389 : {
1390 : struct irq_domain *domain;
1391 :
1392 0 : if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY))
1393 : return 0;
1394 :
1395 0 : domain = irq_domain_create_linear(adap->dev.parent->fwnode,
1396 : I2C_ADDR_7BITS_COUNT,
1397 : &i2c_host_notify_irq_ops, adap);
1398 0 : if (!domain)
1399 : return -ENOMEM;
1400 :
1401 0 : adap->host_notify_domain = domain;
1402 :
1403 0 : return 0;
1404 : }
1405 :
1406 : /**
1407 : * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct
1408 : * I2C client.
1409 : * @adap: the adapter
1410 : * @addr: the I2C address of the notifying device
1411 : * Context: can't sleep
1412 : *
1413 : * Helper function to be called from an I2C bus driver's interrupt
1414 : * handler. It will schedule the Host Notify IRQ.
1415 : */
1416 0 : int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr)
1417 : {
1418 : int irq;
1419 :
1420 0 : if (!adap)
1421 : return -EINVAL;
1422 :
1423 0 : irq = irq_find_mapping(adap->host_notify_domain, addr);
1424 0 : if (irq <= 0)
1425 : return -ENXIO;
1426 :
1427 0 : generic_handle_irq_safe(irq);
1428 :
1429 0 : return 0;
1430 : }
1431 : EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify);
1432 :
1433 0 : static int i2c_register_adapter(struct i2c_adapter *adap)
1434 : {
1435 0 : int res = -EINVAL;
1436 :
1437 : /* Can't register until after driver model init */
1438 0 : if (WARN_ON(!is_registered)) {
1439 : res = -EAGAIN;
1440 : goto out_list;
1441 : }
1442 :
1443 : /* Sanity checks */
1444 0 : if (WARN(!adap->name[0], "i2c adapter has no name"))
1445 : goto out_list;
1446 :
1447 0 : if (!adap->algo) {
1448 0 : pr_err("adapter '%s': no algo supplied!\n", adap->name);
1449 0 : goto out_list;
1450 : }
1451 :
1452 0 : if (!adap->lock_ops)
1453 0 : adap->lock_ops = &i2c_adapter_lock_ops;
1454 :
1455 0 : adap->locked_flags = 0;
1456 0 : rt_mutex_init(&adap->bus_lock);
1457 0 : rt_mutex_init(&adap->mux_lock);
1458 0 : mutex_init(&adap->userspace_clients_lock);
1459 0 : INIT_LIST_HEAD(&adap->userspace_clients);
1460 :
1461 : /* Set default timeout to 1 second if not already set */
1462 0 : if (adap->timeout == 0)
1463 0 : adap->timeout = HZ;
1464 :
1465 : /* register soft irqs for Host Notify */
1466 0 : res = i2c_setup_host_notify_irq_domain(adap);
1467 0 : if (res) {
1468 0 : pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n",
1469 : adap->name, res);
1470 0 : goto out_list;
1471 : }
1472 :
1473 0 : dev_set_name(&adap->dev, "i2c-%d", adap->nr);
1474 0 : adap->dev.bus = &i2c_bus_type;
1475 0 : adap->dev.type = &i2c_adapter_type;
1476 0 : res = device_register(&adap->dev);
1477 0 : if (res) {
1478 0 : pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
1479 0 : goto out_list;
1480 : }
1481 :
1482 0 : res = i2c_setup_smbus_alert(adap);
1483 : if (res)
1484 : goto out_reg;
1485 :
1486 0 : device_enable_async_suspend(&adap->dev);
1487 0 : pm_runtime_no_callbacks(&adap->dev);
1488 0 : pm_suspend_ignore_children(&adap->dev, true);
1489 0 : pm_runtime_enable(&adap->dev);
1490 :
1491 0 : res = i2c_init_recovery(adap);
1492 0 : if (res == -EPROBE_DEFER)
1493 : goto out_reg;
1494 :
1495 : dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
1496 :
1497 : #ifdef CONFIG_I2C_COMPAT
1498 0 : res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev,
1499 : adap->dev.parent);
1500 0 : if (res)
1501 0 : dev_warn(&adap->dev,
1502 : "Failed to create compatibility class link\n");
1503 : #endif
1504 :
1505 : /* create pre-declared device nodes */
1506 0 : of_i2c_register_devices(adap);
1507 0 : i2c_acpi_install_space_handler(adap);
1508 0 : i2c_acpi_register_devices(adap);
1509 :
1510 0 : if (adap->nr < __i2c_first_dynamic_bus_num)
1511 0 : i2c_scan_static_board_info(adap);
1512 :
1513 : /* Notify drivers */
1514 0 : mutex_lock(&core_lock);
1515 0 : bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter);
1516 0 : mutex_unlock(&core_lock);
1517 :
1518 0 : return 0;
1519 :
1520 : out_reg:
1521 0 : init_completion(&adap->dev_released);
1522 0 : device_unregister(&adap->dev);
1523 0 : wait_for_completion(&adap->dev_released);
1524 : out_list:
1525 0 : mutex_lock(&core_lock);
1526 0 : idr_remove(&i2c_adapter_idr, adap->nr);
1527 0 : mutex_unlock(&core_lock);
1528 0 : return res;
1529 : }
1530 :
1531 : /**
1532 : * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1
1533 : * @adap: the adapter to register (with adap->nr initialized)
1534 : * Context: can sleep
1535 : *
1536 : * See i2c_add_numbered_adapter() for details.
1537 : */
1538 0 : static int __i2c_add_numbered_adapter(struct i2c_adapter *adap)
1539 : {
1540 : int id;
1541 :
1542 0 : mutex_lock(&core_lock);
1543 0 : id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL);
1544 0 : mutex_unlock(&core_lock);
1545 0 : if (WARN(id < 0, "couldn't get idr"))
1546 0 : return id == -ENOSPC ? -EBUSY : id;
1547 :
1548 0 : return i2c_register_adapter(adap);
1549 : }
1550 :
1551 : /**
1552 : * i2c_add_adapter - declare i2c adapter, use dynamic bus number
1553 : * @adapter: the adapter to add
1554 : * Context: can sleep
1555 : *
1556 : * This routine is used to declare an I2C adapter when its bus number
1557 : * doesn't matter or when its bus number is specified by an dt alias.
1558 : * Examples of bases when the bus number doesn't matter: I2C adapters
1559 : * dynamically added by USB links or PCI plugin cards.
1560 : *
1561 : * When this returns zero, a new bus number was allocated and stored
1562 : * in adap->nr, and the specified adapter became available for clients.
1563 : * Otherwise, a negative errno value is returned.
1564 : */
1565 0 : int i2c_add_adapter(struct i2c_adapter *adapter)
1566 : {
1567 0 : struct device *dev = &adapter->dev;
1568 : int id;
1569 :
1570 : if (dev->of_node) {
1571 : id = of_alias_get_id(dev->of_node, "i2c");
1572 : if (id >= 0) {
1573 : adapter->nr = id;
1574 : return __i2c_add_numbered_adapter(adapter);
1575 : }
1576 : }
1577 :
1578 0 : mutex_lock(&core_lock);
1579 0 : id = idr_alloc(&i2c_adapter_idr, adapter,
1580 : __i2c_first_dynamic_bus_num, 0, GFP_KERNEL);
1581 0 : mutex_unlock(&core_lock);
1582 0 : if (WARN(id < 0, "couldn't get idr"))
1583 : return id;
1584 :
1585 0 : adapter->nr = id;
1586 :
1587 0 : return i2c_register_adapter(adapter);
1588 : }
1589 : EXPORT_SYMBOL(i2c_add_adapter);
1590 :
1591 : /**
1592 : * i2c_add_numbered_adapter - declare i2c adapter, use static bus number
1593 : * @adap: the adapter to register (with adap->nr initialized)
1594 : * Context: can sleep
1595 : *
1596 : * This routine is used to declare an I2C adapter when its bus number
1597 : * matters. For example, use it for I2C adapters from system-on-chip CPUs,
1598 : * or otherwise built in to the system's mainboard, and where i2c_board_info
1599 : * is used to properly configure I2C devices.
1600 : *
1601 : * If the requested bus number is set to -1, then this function will behave
1602 : * identically to i2c_add_adapter, and will dynamically assign a bus number.
1603 : *
1604 : * If no devices have pre-been declared for this bus, then be sure to
1605 : * register the adapter before any dynamically allocated ones. Otherwise
1606 : * the required bus ID may not be available.
1607 : *
1608 : * When this returns zero, the specified adapter became available for
1609 : * clients using the bus number provided in adap->nr. Also, the table
1610 : * of I2C devices pre-declared using i2c_register_board_info() is scanned,
1611 : * and the appropriate driver model device nodes are created. Otherwise, a
1612 : * negative errno value is returned.
1613 : */
1614 0 : int i2c_add_numbered_adapter(struct i2c_adapter *adap)
1615 : {
1616 0 : if (adap->nr == -1) /* -1 means dynamically assign bus id */
1617 0 : return i2c_add_adapter(adap);
1618 :
1619 0 : return __i2c_add_numbered_adapter(adap);
1620 : }
1621 : EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
1622 :
1623 0 : static void i2c_do_del_adapter(struct i2c_driver *driver,
1624 : struct i2c_adapter *adapter)
1625 : {
1626 : struct i2c_client *client, *_n;
1627 :
1628 : /* Remove the devices we created ourselves as the result of hardware
1629 : * probing (using a driver's detect method) */
1630 0 : list_for_each_entry_safe(client, _n, &driver->clients, detected) {
1631 0 : if (client->adapter == adapter) {
1632 : dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",
1633 : client->name, client->addr);
1634 0 : list_del(&client->detected);
1635 0 : i2c_unregister_device(client);
1636 : }
1637 : }
1638 0 : }
1639 :
1640 0 : static int __unregister_client(struct device *dev, void *dummy)
1641 : {
1642 0 : struct i2c_client *client = i2c_verify_client(dev);
1643 0 : if (client && strcmp(client->name, "dummy"))
1644 0 : i2c_unregister_device(client);
1645 0 : return 0;
1646 : }
1647 :
1648 0 : static int __unregister_dummy(struct device *dev, void *dummy)
1649 : {
1650 0 : struct i2c_client *client = i2c_verify_client(dev);
1651 0 : i2c_unregister_device(client);
1652 0 : return 0;
1653 : }
1654 :
1655 0 : static int __process_removed_adapter(struct device_driver *d, void *data)
1656 : {
1657 0 : i2c_do_del_adapter(to_i2c_driver(d), data);
1658 0 : return 0;
1659 : }
1660 :
1661 : /**
1662 : * i2c_del_adapter - unregister I2C adapter
1663 : * @adap: the adapter being unregistered
1664 : * Context: can sleep
1665 : *
1666 : * This unregisters an I2C adapter which was previously registered
1667 : * by @i2c_add_adapter or @i2c_add_numbered_adapter.
1668 : */
1669 0 : void i2c_del_adapter(struct i2c_adapter *adap)
1670 : {
1671 : struct i2c_adapter *found;
1672 : struct i2c_client *client, *next;
1673 :
1674 : /* First make sure that this adapter was ever added */
1675 0 : mutex_lock(&core_lock);
1676 0 : found = idr_find(&i2c_adapter_idr, adap->nr);
1677 0 : mutex_unlock(&core_lock);
1678 0 : if (found != adap) {
1679 : pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name);
1680 : return;
1681 : }
1682 :
1683 0 : i2c_acpi_remove_space_handler(adap);
1684 : /* Tell drivers about this removal */
1685 0 : mutex_lock(&core_lock);
1686 0 : bus_for_each_drv(&i2c_bus_type, NULL, adap,
1687 : __process_removed_adapter);
1688 0 : mutex_unlock(&core_lock);
1689 :
1690 : /* Remove devices instantiated from sysfs */
1691 0 : mutex_lock_nested(&adap->userspace_clients_lock,
1692 : i2c_adapter_depth(adap));
1693 0 : list_for_each_entry_safe(client, next, &adap->userspace_clients,
1694 : detected) {
1695 : dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,
1696 : client->addr);
1697 0 : list_del(&client->detected);
1698 0 : i2c_unregister_device(client);
1699 : }
1700 0 : mutex_unlock(&adap->userspace_clients_lock);
1701 :
1702 : /* Detach any active clients. This can't fail, thus we do not
1703 : * check the returned value. This is a two-pass process, because
1704 : * we can't remove the dummy devices during the first pass: they
1705 : * could have been instantiated by real devices wishing to clean
1706 : * them up properly, so we give them a chance to do that first. */
1707 0 : device_for_each_child(&adap->dev, NULL, __unregister_client);
1708 0 : device_for_each_child(&adap->dev, NULL, __unregister_dummy);
1709 :
1710 : #ifdef CONFIG_I2C_COMPAT
1711 0 : class_compat_remove_link(i2c_adapter_compat_class, &adap->dev,
1712 : adap->dev.parent);
1713 : #endif
1714 :
1715 : /* device name is gone after device_unregister */
1716 : dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
1717 :
1718 0 : pm_runtime_disable(&adap->dev);
1719 :
1720 0 : i2c_host_notify_irq_teardown(adap);
1721 :
1722 : /* wait until all references to the device are gone
1723 : *
1724 : * FIXME: This is old code and should ideally be replaced by an
1725 : * alternative which results in decoupling the lifetime of the struct
1726 : * device from the i2c_adapter, like spi or netdev do. Any solution
1727 : * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled!
1728 : */
1729 0 : init_completion(&adap->dev_released);
1730 0 : device_unregister(&adap->dev);
1731 0 : wait_for_completion(&adap->dev_released);
1732 :
1733 : /* free bus id */
1734 0 : mutex_lock(&core_lock);
1735 0 : idr_remove(&i2c_adapter_idr, adap->nr);
1736 0 : mutex_unlock(&core_lock);
1737 :
1738 : /* Clear the device structure in case this adapter is ever going to be
1739 : added again */
1740 0 : memset(&adap->dev, 0, sizeof(adap->dev));
1741 : }
1742 : EXPORT_SYMBOL(i2c_del_adapter);
1743 :
1744 0 : static void devm_i2c_del_adapter(void *adapter)
1745 : {
1746 0 : i2c_del_adapter(adapter);
1747 0 : }
1748 :
1749 : /**
1750 : * devm_i2c_add_adapter - device-managed variant of i2c_add_adapter()
1751 : * @dev: managing device for adding this I2C adapter
1752 : * @adapter: the adapter to add
1753 : * Context: can sleep
1754 : *
1755 : * Add adapter with dynamic bus number, same with i2c_add_adapter()
1756 : * but the adapter will be auto deleted on driver detach.
1757 : */
1758 0 : int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter)
1759 : {
1760 : int ret;
1761 :
1762 0 : ret = i2c_add_adapter(adapter);
1763 0 : if (ret)
1764 : return ret;
1765 :
1766 : return devm_add_action_or_reset(dev, devm_i2c_del_adapter, adapter);
1767 : }
1768 : EXPORT_SYMBOL_GPL(devm_i2c_add_adapter);
1769 :
1770 : static void i2c_parse_timing(struct device *dev, char *prop_name, u32 *cur_val_p,
1771 : u32 def_val, bool use_def)
1772 : {
1773 : int ret;
1774 :
1775 0 : ret = device_property_read_u32(dev, prop_name, cur_val_p);
1776 0 : if (ret && use_def)
1777 0 : *cur_val_p = def_val;
1778 :
1779 : dev_dbg(dev, "%s: %u\n", prop_name, *cur_val_p);
1780 : }
1781 :
1782 : /**
1783 : * i2c_parse_fw_timings - get I2C related timing parameters from firmware
1784 : * @dev: The device to scan for I2C timing properties
1785 : * @t: the i2c_timings struct to be filled with values
1786 : * @use_defaults: bool to use sane defaults derived from the I2C specification
1787 : * when properties are not found, otherwise don't update
1788 : *
1789 : * Scan the device for the generic I2C properties describing timing parameters
1790 : * for the signal and fill the given struct with the results. If a property was
1791 : * not found and use_defaults was true, then maximum timings are assumed which
1792 : * are derived from the I2C specification. If use_defaults is not used, the
1793 : * results will be as before, so drivers can apply their own defaults before
1794 : * calling this helper. The latter is mainly intended for avoiding regressions
1795 : * of existing drivers which want to switch to this function. New drivers
1796 : * almost always should use the defaults.
1797 : */
1798 0 : void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults)
1799 : {
1800 0 : bool u = use_defaults;
1801 : u32 d;
1802 :
1803 0 : i2c_parse_timing(dev, "clock-frequency", &t->bus_freq_hz,
1804 : I2C_MAX_STANDARD_MODE_FREQ, u);
1805 :
1806 0 : d = t->bus_freq_hz <= I2C_MAX_STANDARD_MODE_FREQ ? 1000 :
1807 : t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120;
1808 0 : i2c_parse_timing(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns, d, u);
1809 :
1810 0 : d = t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120;
1811 0 : i2c_parse_timing(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns, d, u);
1812 :
1813 0 : i2c_parse_timing(dev, "i2c-scl-internal-delay-ns",
1814 : &t->scl_int_delay_ns, 0, u);
1815 0 : i2c_parse_timing(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns,
1816 : t->scl_fall_ns, u);
1817 0 : i2c_parse_timing(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns, 0, u);
1818 0 : i2c_parse_timing(dev, "i2c-digital-filter-width-ns",
1819 : &t->digital_filter_width_ns, 0, u);
1820 0 : i2c_parse_timing(dev, "i2c-analog-filter-cutoff-frequency",
1821 : &t->analog_filter_cutoff_freq_hz, 0, u);
1822 0 : }
1823 : EXPORT_SYMBOL_GPL(i2c_parse_fw_timings);
1824 :
1825 : /* ------------------------------------------------------------------------- */
1826 :
1827 1 : int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data))
1828 : {
1829 : int res;
1830 :
1831 1 : mutex_lock(&core_lock);
1832 1 : res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn);
1833 1 : mutex_unlock(&core_lock);
1834 :
1835 1 : return res;
1836 : }
1837 : EXPORT_SYMBOL_GPL(i2c_for_each_dev);
1838 :
1839 0 : static int __process_new_driver(struct device *dev, void *data)
1840 : {
1841 0 : if (dev->type != &i2c_adapter_type)
1842 : return 0;
1843 0 : return i2c_do_add_adapter(data, to_i2c_adapter(dev));
1844 : }
1845 :
1846 : /*
1847 : * An i2c_driver is used with one or more i2c_client (device) nodes to access
1848 : * i2c slave chips, on a bus instance associated with some i2c_adapter.
1849 : */
1850 :
1851 1 : int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
1852 : {
1853 : int res;
1854 :
1855 : /* Can't register until after driver model init */
1856 1 : if (WARN_ON(!is_registered))
1857 : return -EAGAIN;
1858 :
1859 : /* add the driver to the list of i2c drivers in the driver core */
1860 1 : driver->driver.owner = owner;
1861 1 : driver->driver.bus = &i2c_bus_type;
1862 2 : INIT_LIST_HEAD(&driver->clients);
1863 :
1864 : /* When registration returns, the driver core
1865 : * will have called probe() for all matching-but-unbound devices.
1866 : */
1867 1 : res = driver_register(&driver->driver);
1868 1 : if (res)
1869 : return res;
1870 :
1871 : pr_debug("driver [%s] registered\n", driver->driver.name);
1872 :
1873 : /* Walk the adapters that are already present */
1874 1 : i2c_for_each_dev(driver, __process_new_driver);
1875 :
1876 1 : return 0;
1877 : }
1878 : EXPORT_SYMBOL(i2c_register_driver);
1879 :
1880 0 : static int __process_removed_driver(struct device *dev, void *data)
1881 : {
1882 0 : if (dev->type == &i2c_adapter_type)
1883 0 : i2c_do_del_adapter(data, to_i2c_adapter(dev));
1884 0 : return 0;
1885 : }
1886 :
1887 : /**
1888 : * i2c_del_driver - unregister I2C driver
1889 : * @driver: the driver being unregistered
1890 : * Context: can sleep
1891 : */
1892 0 : void i2c_del_driver(struct i2c_driver *driver)
1893 : {
1894 0 : i2c_for_each_dev(driver, __process_removed_driver);
1895 :
1896 0 : driver_unregister(&driver->driver);
1897 : pr_debug("driver [%s] unregistered\n", driver->driver.name);
1898 0 : }
1899 : EXPORT_SYMBOL(i2c_del_driver);
1900 :
1901 : /* ------------------------------------------------------------------------- */
1902 :
1903 : struct i2c_cmd_arg {
1904 : unsigned cmd;
1905 : void *arg;
1906 : };
1907 :
1908 0 : static int i2c_cmd(struct device *dev, void *_arg)
1909 : {
1910 0 : struct i2c_client *client = i2c_verify_client(dev);
1911 0 : struct i2c_cmd_arg *arg = _arg;
1912 : struct i2c_driver *driver;
1913 :
1914 0 : if (!client || !client->dev.driver)
1915 : return 0;
1916 :
1917 0 : driver = to_i2c_driver(client->dev.driver);
1918 0 : if (driver->command)
1919 0 : driver->command(client, arg->cmd, arg->arg);
1920 : return 0;
1921 : }
1922 :
1923 0 : void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
1924 : {
1925 : struct i2c_cmd_arg cmd_arg;
1926 :
1927 0 : cmd_arg.cmd = cmd;
1928 0 : cmd_arg.arg = arg;
1929 0 : device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);
1930 0 : }
1931 : EXPORT_SYMBOL(i2c_clients_command);
1932 :
1933 1 : static int __init i2c_init(void)
1934 : {
1935 : int retval;
1936 :
1937 1 : retval = of_alias_get_highest_id("i2c");
1938 :
1939 1 : down_write(&__i2c_board_lock);
1940 1 : if (retval >= __i2c_first_dynamic_bus_num)
1941 0 : __i2c_first_dynamic_bus_num = retval + 1;
1942 1 : up_write(&__i2c_board_lock);
1943 :
1944 1 : retval = bus_register(&i2c_bus_type);
1945 1 : if (retval)
1946 : return retval;
1947 :
1948 1 : is_registered = true;
1949 :
1950 : #ifdef CONFIG_I2C_COMPAT
1951 1 : i2c_adapter_compat_class = class_compat_register("i2c-adapter");
1952 1 : if (!i2c_adapter_compat_class) {
1953 : retval = -ENOMEM;
1954 : goto bus_err;
1955 : }
1956 : #endif
1957 1 : retval = i2c_add_driver(&dummy_driver);
1958 1 : if (retval)
1959 : goto class_err;
1960 :
1961 : if (IS_ENABLED(CONFIG_OF_DYNAMIC))
1962 : WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier));
1963 : if (IS_ENABLED(CONFIG_ACPI))
1964 : WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier));
1965 :
1966 : return 0;
1967 :
1968 : class_err:
1969 : #ifdef CONFIG_I2C_COMPAT
1970 0 : class_compat_unregister(i2c_adapter_compat_class);
1971 : bus_err:
1972 : #endif
1973 0 : is_registered = false;
1974 0 : bus_unregister(&i2c_bus_type);
1975 0 : return retval;
1976 : }
1977 :
1978 0 : static void __exit i2c_exit(void)
1979 : {
1980 : if (IS_ENABLED(CONFIG_ACPI))
1981 : WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier));
1982 : if (IS_ENABLED(CONFIG_OF_DYNAMIC))
1983 : WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier));
1984 0 : i2c_del_driver(&dummy_driver);
1985 : #ifdef CONFIG_I2C_COMPAT
1986 0 : class_compat_unregister(i2c_adapter_compat_class);
1987 : #endif
1988 0 : bus_unregister(&i2c_bus_type);
1989 : tracepoint_synchronize_unregister();
1990 0 : }
1991 :
1992 : /* We must initialize early, because some subsystems register i2c drivers
1993 : * in subsys_initcall() code, but are linked (and initialized) before i2c.
1994 : */
1995 : postcore_initcall(i2c_init);
1996 : module_exit(i2c_exit);
1997 :
1998 : /* ----------------------------------------------------
1999 : * the functional interface to the i2c busses.
2000 : * ----------------------------------------------------
2001 : */
2002 :
2003 : /* Check if val is exceeding the quirk IFF quirk is non 0 */
2004 : #define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk)))
2005 :
2006 0 : static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg)
2007 : {
2008 0 : dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n",
2009 : err_msg, msg->addr, msg->len,
2010 : msg->flags & I2C_M_RD ? "read" : "write");
2011 0 : return -EOPNOTSUPP;
2012 : }
2013 :
2014 0 : static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
2015 : {
2016 0 : const struct i2c_adapter_quirks *q = adap->quirks;
2017 0 : int max_num = q->max_num_msgs, i;
2018 0 : bool do_len_check = true;
2019 :
2020 0 : if (q->flags & I2C_AQ_COMB) {
2021 0 : max_num = 2;
2022 :
2023 : /* special checks for combined messages */
2024 0 : if (num == 2) {
2025 0 : if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD)
2026 0 : return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write");
2027 :
2028 0 : if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD))
2029 0 : return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read");
2030 :
2031 0 : if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr)
2032 0 : return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr");
2033 :
2034 0 : if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len))
2035 0 : return i2c_quirk_error(adap, &msgs[0], "msg too long");
2036 :
2037 0 : if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len))
2038 0 : return i2c_quirk_error(adap, &msgs[1], "msg too long");
2039 :
2040 : do_len_check = false;
2041 : }
2042 : }
2043 :
2044 0 : if (i2c_quirk_exceeded(num, max_num))
2045 0 : return i2c_quirk_error(adap, &msgs[0], "too many messages");
2046 :
2047 0 : for (i = 0; i < num; i++) {
2048 0 : u16 len = msgs[i].len;
2049 :
2050 0 : if (msgs[i].flags & I2C_M_RD) {
2051 0 : if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len))
2052 0 : return i2c_quirk_error(adap, &msgs[i], "msg too long");
2053 :
2054 0 : if (q->flags & I2C_AQ_NO_ZERO_LEN_READ && len == 0)
2055 0 : return i2c_quirk_error(adap, &msgs[i], "no zero length");
2056 : } else {
2057 0 : if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len))
2058 0 : return i2c_quirk_error(adap, &msgs[i], "msg too long");
2059 :
2060 0 : if (q->flags & I2C_AQ_NO_ZERO_LEN_WRITE && len == 0)
2061 0 : return i2c_quirk_error(adap, &msgs[i], "no zero length");
2062 : }
2063 : }
2064 :
2065 : return 0;
2066 : }
2067 :
2068 : /**
2069 : * __i2c_transfer - unlocked flavor of i2c_transfer
2070 : * @adap: Handle to I2C bus
2071 : * @msgs: One or more messages to execute before STOP is issued to
2072 : * terminate the operation; each message begins with a START.
2073 : * @num: Number of messages to be executed.
2074 : *
2075 : * Returns negative errno, else the number of messages executed.
2076 : *
2077 : * Adapter lock must be held when calling this function. No debug logging
2078 : * takes place. adap->algo->master_xfer existence isn't checked.
2079 : */
2080 0 : int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
2081 : {
2082 : unsigned long orig_jiffies;
2083 : int ret, try;
2084 :
2085 0 : if (WARN_ON(!msgs || num < 1))
2086 : return -EINVAL;
2087 :
2088 0 : ret = __i2c_check_suspended(adap);
2089 0 : if (ret)
2090 : return ret;
2091 :
2092 0 : if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))
2093 : return -EOPNOTSUPP;
2094 :
2095 : /*
2096 : * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets
2097 : * enabled. This is an efficient way of keeping the for-loop from
2098 : * being executed when not needed.
2099 : */
2100 0 : if (static_branch_unlikely(&i2c_trace_msg_key)) {
2101 : int i;
2102 : for (i = 0; i < num; i++)
2103 : if (msgs[i].flags & I2C_M_RD)
2104 : trace_i2c_read(adap, &msgs[i], i);
2105 : else
2106 : trace_i2c_write(adap, &msgs[i], i);
2107 : }
2108 :
2109 : /* Retry automatically on arbitration loss */
2110 0 : orig_jiffies = jiffies;
2111 0 : for (ret = 0, try = 0; try <= adap->retries; try++) {
2112 0 : if (i2c_in_atomic_xfer_mode() && adap->algo->master_xfer_atomic)
2113 0 : ret = adap->algo->master_xfer_atomic(adap, msgs, num);
2114 : else
2115 0 : ret = adap->algo->master_xfer(adap, msgs, num);
2116 :
2117 0 : if (ret != -EAGAIN)
2118 : break;
2119 0 : if (time_after(jiffies, orig_jiffies + adap->timeout))
2120 : break;
2121 : }
2122 :
2123 0 : if (static_branch_unlikely(&i2c_trace_msg_key)) {
2124 : int i;
2125 : for (i = 0; i < ret; i++)
2126 : if (msgs[i].flags & I2C_M_RD)
2127 : trace_i2c_reply(adap, &msgs[i], i);
2128 : trace_i2c_result(adap, num, ret);
2129 : }
2130 :
2131 : return ret;
2132 : }
2133 : EXPORT_SYMBOL(__i2c_transfer);
2134 :
2135 : /**
2136 : * i2c_transfer - execute a single or combined I2C message
2137 : * @adap: Handle to I2C bus
2138 : * @msgs: One or more messages to execute before STOP is issued to
2139 : * terminate the operation; each message begins with a START.
2140 : * @num: Number of messages to be executed.
2141 : *
2142 : * Returns negative errno, else the number of messages executed.
2143 : *
2144 : * Note that there is no requirement that each message be sent to
2145 : * the same slave address, although that is the most common model.
2146 : */
2147 0 : int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
2148 : {
2149 : int ret;
2150 :
2151 0 : if (!adap->algo->master_xfer) {
2152 : dev_dbg(&adap->dev, "I2C level transfers not supported\n");
2153 : return -EOPNOTSUPP;
2154 : }
2155 :
2156 : /* REVISIT the fault reporting model here is weak:
2157 : *
2158 : * - When we get an error after receiving N bytes from a slave,
2159 : * there is no way to report "N".
2160 : *
2161 : * - When we get a NAK after transmitting N bytes to a slave,
2162 : * there is no way to report "N" ... or to let the master
2163 : * continue executing the rest of this combined message, if
2164 : * that's the appropriate response.
2165 : *
2166 : * - When for example "num" is two and we successfully complete
2167 : * the first message but get an error part way through the
2168 : * second, it's unclear whether that should be reported as
2169 : * one (discarding status on the second message) or errno
2170 : * (discarding status on the first one).
2171 : */
2172 0 : ret = __i2c_lock_bus_helper(adap);
2173 0 : if (ret)
2174 : return ret;
2175 :
2176 0 : ret = __i2c_transfer(adap, msgs, num);
2177 0 : i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
2178 :
2179 0 : return ret;
2180 : }
2181 : EXPORT_SYMBOL(i2c_transfer);
2182 :
2183 : /**
2184 : * i2c_transfer_buffer_flags - issue a single I2C message transferring data
2185 : * to/from a buffer
2186 : * @client: Handle to slave device
2187 : * @buf: Where the data is stored
2188 : * @count: How many bytes to transfer, must be less than 64k since msg.len is u16
2189 : * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads
2190 : *
2191 : * Returns negative errno, or else the number of bytes transferred.
2192 : */
2193 0 : int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf,
2194 : int count, u16 flags)
2195 : {
2196 : int ret;
2197 0 : struct i2c_msg msg = {
2198 0 : .addr = client->addr,
2199 0 : .flags = flags | (client->flags & I2C_M_TEN),
2200 : .len = count,
2201 : .buf = buf,
2202 : };
2203 :
2204 0 : ret = i2c_transfer(client->adapter, &msg, 1);
2205 :
2206 : /*
2207 : * If everything went ok (i.e. 1 msg transferred), return #bytes
2208 : * transferred, else error code.
2209 : */
2210 0 : return (ret == 1) ? count : ret;
2211 : }
2212 : EXPORT_SYMBOL(i2c_transfer_buffer_flags);
2213 :
2214 : /**
2215 : * i2c_get_device_id - get manufacturer, part id and die revision of a device
2216 : * @client: The device to query
2217 : * @id: The queried information
2218 : *
2219 : * Returns negative errno on error, zero on success.
2220 : */
2221 0 : int i2c_get_device_id(const struct i2c_client *client,
2222 : struct i2c_device_identity *id)
2223 : {
2224 0 : struct i2c_adapter *adap = client->adapter;
2225 : union i2c_smbus_data raw_id;
2226 : int ret;
2227 :
2228 0 : if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
2229 : return -EOPNOTSUPP;
2230 :
2231 0 : raw_id.block[0] = 3;
2232 0 : ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0,
2233 0 : I2C_SMBUS_READ, client->addr << 1,
2234 : I2C_SMBUS_I2C_BLOCK_DATA, &raw_id);
2235 0 : if (ret)
2236 : return ret;
2237 :
2238 0 : id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4);
2239 0 : id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3);
2240 0 : id->die_revision = raw_id.block[3] & 0x7;
2241 0 : return 0;
2242 : }
2243 : EXPORT_SYMBOL_GPL(i2c_get_device_id);
2244 :
2245 : /* ----------------------------------------------------
2246 : * the i2c address scanning function
2247 : * Will not work for 10-bit addresses!
2248 : * ----------------------------------------------------
2249 : */
2250 :
2251 : /*
2252 : * Legacy default probe function, mostly relevant for SMBus. The default
2253 : * probe method is a quick write, but it is known to corrupt the 24RF08
2254 : * EEPROMs due to a state machine bug, and could also irreversibly
2255 : * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f,
2256 : * we use a short byte read instead. Also, some bus drivers don't implement
2257 : * quick write, so we fallback to a byte read in that case too.
2258 : * On x86, there is another special case for FSC hardware monitoring chips,
2259 : * which want regular byte reads (address 0x73.) Fortunately, these are the
2260 : * only known chips using this I2C address on PC hardware.
2261 : * Returns 1 if probe succeeded, 0 if not.
2262 : */
2263 0 : static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr)
2264 : {
2265 : int err;
2266 : union i2c_smbus_data dummy;
2267 :
2268 : #ifdef CONFIG_X86
2269 : if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON)
2270 : && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA))
2271 : err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
2272 : I2C_SMBUS_BYTE_DATA, &dummy);
2273 : else
2274 : #endif
2275 0 : if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50)
2276 0 : && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK))
2277 0 : err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0,
2278 : I2C_SMBUS_QUICK, NULL);
2279 0 : else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE))
2280 0 : err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
2281 : I2C_SMBUS_BYTE, &dummy);
2282 : else {
2283 0 : dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n",
2284 : addr);
2285 0 : err = -EOPNOTSUPP;
2286 : }
2287 :
2288 0 : return err >= 0;
2289 : }
2290 :
2291 0 : static int i2c_detect_address(struct i2c_client *temp_client,
2292 : struct i2c_driver *driver)
2293 : {
2294 : struct i2c_board_info info;
2295 0 : struct i2c_adapter *adapter = temp_client->adapter;
2296 0 : int addr = temp_client->addr;
2297 : int err;
2298 :
2299 : /* Make sure the address is valid */
2300 0 : err = i2c_check_7bit_addr_validity_strict(addr);
2301 0 : if (err) {
2302 0 : dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
2303 : addr);
2304 0 : return err;
2305 : }
2306 :
2307 : /* Skip if already in use (7 bit, no need to encode flags) */
2308 0 : if (i2c_check_addr_busy(adapter, addr))
2309 : return 0;
2310 :
2311 : /* Make sure there is something at this address */
2312 0 : if (!i2c_default_probe(adapter, addr))
2313 : return 0;
2314 :
2315 : /* Finally call the custom detection function */
2316 0 : memset(&info, 0, sizeof(struct i2c_board_info));
2317 0 : info.addr = addr;
2318 0 : err = driver->detect(temp_client, &info);
2319 0 : if (err) {
2320 : /* -ENODEV is returned if the detection fails. We catch it
2321 : here as this isn't an error. */
2322 0 : return err == -ENODEV ? 0 : err;
2323 : }
2324 :
2325 : /* Consistency check */
2326 0 : if (info.type[0] == '\0') {
2327 0 : dev_err(&adapter->dev,
2328 : "%s detection function provided no name for 0x%x\n",
2329 : driver->driver.name, addr);
2330 : } else {
2331 : struct i2c_client *client;
2332 :
2333 : /* Detection succeeded, instantiate the device */
2334 0 : if (adapter->class & I2C_CLASS_DEPRECATED)
2335 0 : dev_warn(&adapter->dev,
2336 : "This adapter will soon drop class based instantiation of devices. "
2337 : "Please make sure client 0x%02x gets instantiated by other means. "
2338 : "Check 'Documentation/i2c/instantiating-devices.rst' for details.\n",
2339 : info.addr);
2340 :
2341 : dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
2342 : info.type, info.addr);
2343 0 : client = i2c_new_client_device(adapter, &info);
2344 0 : if (!IS_ERR(client))
2345 0 : list_add_tail(&client->detected, &driver->clients);
2346 : else
2347 0 : dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n",
2348 : info.type, info.addr);
2349 : }
2350 : return 0;
2351 : }
2352 :
2353 0 : static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
2354 : {
2355 : const unsigned short *address_list;
2356 : struct i2c_client *temp_client;
2357 0 : int i, err = 0;
2358 :
2359 0 : address_list = driver->address_list;
2360 0 : if (!driver->detect || !address_list)
2361 : return 0;
2362 :
2363 : /* Warn that the adapter lost class based instantiation */
2364 0 : if (adapter->class == I2C_CLASS_DEPRECATED) {
2365 : dev_dbg(&adapter->dev,
2366 : "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. "
2367 : "If you need it, check 'Documentation/i2c/instantiating-devices.rst' for alternatives.\n",
2368 : driver->driver.name);
2369 : return 0;
2370 : }
2371 :
2372 : /* Stop here if the classes do not match */
2373 0 : if (!(adapter->class & driver->class))
2374 : return 0;
2375 :
2376 : /* Set up a temporary client to help detect callback */
2377 0 : temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
2378 0 : if (!temp_client)
2379 : return -ENOMEM;
2380 0 : temp_client->adapter = adapter;
2381 :
2382 0 : for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {
2383 : dev_dbg(&adapter->dev,
2384 : "found normal entry for adapter %d, addr 0x%02x\n",
2385 : i2c_adapter_id(adapter), address_list[i]);
2386 0 : temp_client->addr = address_list[i];
2387 0 : err = i2c_detect_address(temp_client, driver);
2388 0 : if (unlikely(err))
2389 : break;
2390 : }
2391 :
2392 0 : kfree(temp_client);
2393 0 : return err;
2394 : }
2395 :
2396 0 : int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr)
2397 : {
2398 0 : return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
2399 0 : I2C_SMBUS_QUICK, NULL) >= 0;
2400 : }
2401 : EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read);
2402 :
2403 : struct i2c_client *
2404 0 : i2c_new_scanned_device(struct i2c_adapter *adap,
2405 : struct i2c_board_info *info,
2406 : unsigned short const *addr_list,
2407 : int (*probe)(struct i2c_adapter *adap, unsigned short addr))
2408 : {
2409 : int i;
2410 :
2411 0 : if (!probe)
2412 0 : probe = i2c_default_probe;
2413 :
2414 0 : for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
2415 : /* Check address validity */
2416 0 : if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) {
2417 0 : dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n",
2418 : addr_list[i]);
2419 0 : continue;
2420 : }
2421 :
2422 : /* Check address availability (7 bit, no need to encode flags) */
2423 0 : if (i2c_check_addr_busy(adap, addr_list[i])) {
2424 : dev_dbg(&adap->dev,
2425 : "Address 0x%02x already in use, not probing\n",
2426 : addr_list[i]);
2427 0 : continue;
2428 : }
2429 :
2430 : /* Test address responsiveness */
2431 0 : if (probe(adap, addr_list[i]))
2432 : break;
2433 : }
2434 :
2435 0 : if (addr_list[i] == I2C_CLIENT_END) {
2436 : dev_dbg(&adap->dev, "Probing failed, no device found\n");
2437 : return ERR_PTR(-ENODEV);
2438 : }
2439 :
2440 0 : info->addr = addr_list[i];
2441 0 : return i2c_new_client_device(adap, info);
2442 : }
2443 : EXPORT_SYMBOL_GPL(i2c_new_scanned_device);
2444 :
2445 0 : struct i2c_adapter *i2c_get_adapter(int nr)
2446 : {
2447 : struct i2c_adapter *adapter;
2448 :
2449 0 : mutex_lock(&core_lock);
2450 0 : adapter = idr_find(&i2c_adapter_idr, nr);
2451 0 : if (!adapter)
2452 : goto exit;
2453 :
2454 0 : if (try_module_get(adapter->owner))
2455 0 : get_device(&adapter->dev);
2456 : else
2457 : adapter = NULL;
2458 :
2459 : exit:
2460 0 : mutex_unlock(&core_lock);
2461 0 : return adapter;
2462 : }
2463 : EXPORT_SYMBOL(i2c_get_adapter);
2464 :
2465 0 : void i2c_put_adapter(struct i2c_adapter *adap)
2466 : {
2467 0 : if (!adap)
2468 : return;
2469 :
2470 0 : put_device(&adap->dev);
2471 0 : module_put(adap->owner);
2472 : }
2473 : EXPORT_SYMBOL(i2c_put_adapter);
2474 :
2475 : /**
2476 : * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg
2477 : * @msg: the message to be checked
2478 : * @threshold: the minimum number of bytes for which using DMA makes sense.
2479 : * Should at least be 1.
2480 : *
2481 : * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO.
2482 : * Or a valid pointer to be used with DMA. After use, release it by
2483 : * calling i2c_put_dma_safe_msg_buf().
2484 : *
2485 : * This function must only be called from process context!
2486 : */
2487 0 : u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold)
2488 : {
2489 : /* also skip 0-length msgs for bogus thresholds of 0 */
2490 : if (!threshold)
2491 : pr_debug("DMA buffer for addr=0x%02x with length 0 is bogus\n",
2492 : msg->addr);
2493 0 : if (msg->len < threshold || msg->len == 0)
2494 : return NULL;
2495 :
2496 0 : if (msg->flags & I2C_M_DMA_SAFE)
2497 0 : return msg->buf;
2498 :
2499 : pr_debug("using bounce buffer for addr=0x%02x, len=%d\n",
2500 : msg->addr, msg->len);
2501 :
2502 0 : if (msg->flags & I2C_M_RD)
2503 0 : return kzalloc(msg->len, GFP_KERNEL);
2504 : else
2505 0 : return kmemdup(msg->buf, msg->len, GFP_KERNEL);
2506 : }
2507 : EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf);
2508 :
2509 : /**
2510 : * i2c_put_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg
2511 : * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL.
2512 : * @msg: the message which the buffer corresponds to
2513 : * @xferred: bool saying if the message was transferred
2514 : */
2515 0 : void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred)
2516 : {
2517 0 : if (!buf || buf == msg->buf)
2518 : return;
2519 :
2520 0 : if (xferred && msg->flags & I2C_M_RD)
2521 0 : memcpy(msg->buf, buf, msg->len);
2522 :
2523 0 : kfree(buf);
2524 : }
2525 : EXPORT_SYMBOL_GPL(i2c_put_dma_safe_msg_buf);
2526 :
2527 : MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
2528 : MODULE_DESCRIPTION("I2C-Bus main module");
2529 : MODULE_LICENSE("GPL");
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