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/pinctrl/devinfo.h>
38 : #include <linux/pm_domain.h>
39 : #include <linux/pm_runtime.h>
40 : #include <linux/pm_wakeirq.h>
41 : #include <linux/property.h>
42 : #include <linux/rwsem.h>
43 : #include <linux/slab.h>
44 :
45 : #include "i2c-core.h"
46 :
47 : #define CREATE_TRACE_POINTS
48 : #include <trace/events/i2c.h>
49 :
50 : #define I2C_ADDR_OFFSET_TEN_BIT 0xa000
51 : #define I2C_ADDR_OFFSET_SLAVE 0x1000
52 :
53 : #define I2C_ADDR_7BITS_MAX 0x77
54 : #define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1)
55 :
56 : #define I2C_ADDR_DEVICE_ID 0x7c
57 :
58 : /*
59 : * core_lock protects i2c_adapter_idr, and guarantees that device detection,
60 : * deletion of detected devices are serialized
61 : */
62 : static DEFINE_MUTEX(core_lock);
63 : static DEFINE_IDR(i2c_adapter_idr);
64 :
65 : static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
66 :
67 : static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key);
68 : static bool is_registered;
69 :
70 0 : int i2c_transfer_trace_reg(void)
71 : {
72 0 : static_branch_inc(&i2c_trace_msg_key);
73 0 : return 0;
74 : }
75 :
76 0 : void i2c_transfer_trace_unreg(void)
77 : {
78 0 : static_branch_dec(&i2c_trace_msg_key);
79 0 : }
80 :
81 0 : const char *i2c_freq_mode_string(u32 bus_freq_hz)
82 : {
83 0 : switch (bus_freq_hz) {
84 : case I2C_MAX_STANDARD_MODE_FREQ:
85 : return "Standard Mode (100 kHz)";
86 : case I2C_MAX_FAST_MODE_FREQ:
87 0 : return "Fast Mode (400 kHz)";
88 : case I2C_MAX_FAST_MODE_PLUS_FREQ:
89 0 : return "Fast Mode Plus (1.0 MHz)";
90 : case I2C_MAX_TURBO_MODE_FREQ:
91 0 : return "Turbo Mode (1.4 MHz)";
92 : case I2C_MAX_HIGH_SPEED_MODE_FREQ:
93 0 : return "High Speed Mode (3.4 MHz)";
94 : case I2C_MAX_ULTRA_FAST_MODE_FREQ:
95 0 : return "Ultra Fast Mode (5.0 MHz)";
96 : default:
97 0 : return "Unknown Mode";
98 : }
99 : }
100 : EXPORT_SYMBOL_GPL(i2c_freq_mode_string);
101 :
102 0 : const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
103 : const struct i2c_client *client)
104 : {
105 0 : if (!(id && client))
106 : return NULL;
107 :
108 0 : while (id->name[0]) {
109 0 : if (strcmp(client->name, id->name) == 0)
110 : return id;
111 0 : id++;
112 : }
113 : return NULL;
114 : }
115 : EXPORT_SYMBOL_GPL(i2c_match_id);
116 :
117 0 : const void *i2c_get_match_data(const struct i2c_client *client)
118 : {
119 0 : struct i2c_driver *driver = to_i2c_driver(client->dev.driver);
120 : const struct i2c_device_id *match;
121 : const void *data;
122 :
123 0 : data = device_get_match_data(&client->dev);
124 0 : if (!data) {
125 0 : match = i2c_match_id(driver->id_table, client);
126 0 : if (!match)
127 : return NULL;
128 :
129 0 : data = (const void *)match->driver_data;
130 : }
131 :
132 : return data;
133 : }
134 : EXPORT_SYMBOL(i2c_get_match_data);
135 :
136 0 : static int i2c_device_match(struct device *dev, struct device_driver *drv)
137 : {
138 0 : struct i2c_client *client = i2c_verify_client(dev);
139 : struct i2c_driver *driver;
140 :
141 :
142 : /* Attempt an OF style match */
143 0 : if (i2c_of_match_device(drv->of_match_table, client))
144 : return 1;
145 :
146 : /* Then ACPI style match */
147 0 : if (acpi_driver_match_device(dev, drv))
148 : return 1;
149 :
150 0 : driver = to_i2c_driver(drv);
151 :
152 : /* Finally an I2C match */
153 0 : if (i2c_match_id(driver->id_table, client))
154 : return 1;
155 :
156 0 : return 0;
157 : }
158 :
159 0 : static int i2c_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
160 : {
161 0 : const struct i2c_client *client = to_i2c_client(dev);
162 : int rc;
163 :
164 0 : rc = of_device_uevent_modalias(dev, env);
165 : if (rc != -ENODEV)
166 : return rc;
167 :
168 0 : rc = acpi_device_uevent_modalias(dev, env);
169 : if (rc != -ENODEV)
170 : return rc;
171 :
172 0 : return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name);
173 : }
174 :
175 : /* i2c bus recovery routines */
176 0 : static int get_scl_gpio_value(struct i2c_adapter *adap)
177 : {
178 0 : return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod);
179 : }
180 :
181 0 : static void set_scl_gpio_value(struct i2c_adapter *adap, int val)
182 : {
183 0 : gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val);
184 0 : }
185 :
186 0 : static int get_sda_gpio_value(struct i2c_adapter *adap)
187 : {
188 0 : return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod);
189 : }
190 :
191 : static void set_sda_gpio_value(struct i2c_adapter *adap, int val)
192 : {
193 : gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val);
194 : }
195 :
196 0 : static int i2c_generic_bus_free(struct i2c_adapter *adap)
197 : {
198 0 : struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
199 0 : int ret = -EOPNOTSUPP;
200 :
201 0 : if (bri->get_bus_free)
202 0 : ret = bri->get_bus_free(adap);
203 0 : else if (bri->get_sda)
204 0 : ret = bri->get_sda(adap);
205 :
206 0 : if (ret < 0)
207 : return ret;
208 :
209 0 : return ret ? 0 : -EBUSY;
210 : }
211 :
212 : /*
213 : * We are generating clock pulses. ndelay() determines durating of clk pulses.
214 : * We will generate clock with rate 100 KHz and so duration of both clock levels
215 : * is: delay in ns = (10^6 / 100) / 2
216 : */
217 : #define RECOVERY_NDELAY 5000
218 : #define RECOVERY_CLK_CNT 9
219 :
220 0 : int i2c_generic_scl_recovery(struct i2c_adapter *adap)
221 : {
222 0 : struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
223 0 : int i = 0, scl = 1, ret = 0;
224 :
225 0 : if (bri->prepare_recovery)
226 0 : bri->prepare_recovery(adap);
227 0 : if (bri->pinctrl)
228 : pinctrl_select_state(bri->pinctrl, bri->pins_gpio);
229 :
230 : /*
231 : * If we can set SDA, we will always create a STOP to ensure additional
232 : * pulses will do no harm. This is achieved by letting SDA follow SCL
233 : * half a cycle later. Check the 'incomplete_write_byte' fault injector
234 : * for details. Note that we must honour tsu:sto, 4us, but lets use 5us
235 : * here for simplicity.
236 : */
237 0 : bri->set_scl(adap, scl);
238 0 : ndelay(RECOVERY_NDELAY);
239 0 : if (bri->set_sda)
240 0 : bri->set_sda(adap, scl);
241 : ndelay(RECOVERY_NDELAY / 2);
242 :
243 : /*
244 : * By this time SCL is high, as we need to give 9 falling-rising edges
245 : */
246 0 : while (i++ < RECOVERY_CLK_CNT * 2) {
247 0 : if (scl) {
248 : /* SCL shouldn't be low here */
249 0 : if (!bri->get_scl(adap)) {
250 0 : dev_err(&adap->dev,
251 : "SCL is stuck low, exit recovery\n");
252 0 : ret = -EBUSY;
253 0 : break;
254 : }
255 : }
256 :
257 0 : scl = !scl;
258 0 : bri->set_scl(adap, scl);
259 : /* Creating STOP again, see above */
260 0 : if (scl) {
261 : /* Honour minimum tsu:sto */
262 : ndelay(RECOVERY_NDELAY);
263 : } else {
264 : /* Honour minimum tf and thd:dat */
265 : ndelay(RECOVERY_NDELAY / 2);
266 : }
267 0 : if (bri->set_sda)
268 0 : bri->set_sda(adap, scl);
269 0 : ndelay(RECOVERY_NDELAY / 2);
270 :
271 0 : if (scl) {
272 0 : ret = i2c_generic_bus_free(adap);
273 0 : if (ret == 0)
274 : break;
275 : }
276 : }
277 :
278 : /* If we can't check bus status, assume recovery worked */
279 0 : if (ret == -EOPNOTSUPP)
280 0 : ret = 0;
281 :
282 0 : if (bri->unprepare_recovery)
283 0 : bri->unprepare_recovery(adap);
284 0 : if (bri->pinctrl)
285 : pinctrl_select_state(bri->pinctrl, bri->pins_default);
286 :
287 0 : return ret;
288 : }
289 : EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery);
290 :
291 0 : int i2c_recover_bus(struct i2c_adapter *adap)
292 : {
293 0 : if (!adap->bus_recovery_info)
294 : return -EBUSY;
295 :
296 : dev_dbg(&adap->dev, "Trying i2c bus recovery\n");
297 0 : return adap->bus_recovery_info->recover_bus(adap);
298 : }
299 : EXPORT_SYMBOL_GPL(i2c_recover_bus);
300 :
301 0 : static void i2c_gpio_init_pinctrl_recovery(struct i2c_adapter *adap)
302 : {
303 0 : struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
304 0 : struct device *dev = &adap->dev;
305 0 : struct pinctrl *p = bri->pinctrl ?: dev_pinctrl(dev->parent);
306 :
307 0 : bri->pinctrl = p;
308 :
309 : /*
310 : * we can't change states without pinctrl, so remove the states if
311 : * populated
312 : */
313 0 : if (!p) {
314 0 : bri->pins_default = NULL;
315 0 : bri->pins_gpio = NULL;
316 0 : return;
317 : }
318 :
319 0 : if (!bri->pins_default) {
320 0 : bri->pins_default = pinctrl_lookup_state(p,
321 : PINCTRL_STATE_DEFAULT);
322 0 : if (IS_ERR(bri->pins_default)) {
323 : dev_dbg(dev, PINCTRL_STATE_DEFAULT " state not found for GPIO recovery\n");
324 : bri->pins_default = NULL;
325 : }
326 : }
327 0 : if (!bri->pins_gpio) {
328 0 : bri->pins_gpio = pinctrl_lookup_state(p, "gpio");
329 0 : if (IS_ERR(bri->pins_gpio))
330 : bri->pins_gpio = pinctrl_lookup_state(p, "recovery");
331 :
332 0 : if (IS_ERR(bri->pins_gpio)) {
333 : dev_dbg(dev, "no gpio or recovery state found for GPIO recovery\n");
334 : bri->pins_gpio = NULL;
335 : }
336 : }
337 :
338 : /* for pinctrl state changes, we need all the information */
339 0 : if (bri->pins_default && bri->pins_gpio) {
340 0 : dev_info(dev, "using pinctrl states for GPIO recovery");
341 : } else {
342 0 : bri->pinctrl = NULL;
343 0 : bri->pins_default = NULL;
344 0 : bri->pins_gpio = NULL;
345 : }
346 : }
347 :
348 0 : static int i2c_gpio_init_generic_recovery(struct i2c_adapter *adap)
349 : {
350 0 : struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
351 0 : struct device *dev = &adap->dev;
352 : struct gpio_desc *gpiod;
353 0 : int ret = 0;
354 :
355 : /*
356 : * don't touch the recovery information if the driver is not using
357 : * generic SCL recovery
358 : */
359 0 : if (bri->recover_bus && bri->recover_bus != i2c_generic_scl_recovery)
360 : return 0;
361 :
362 : /*
363 : * pins might be taken as GPIO, so we should inform pinctrl about
364 : * this and move the state to GPIO
365 : */
366 0 : if (bri->pinctrl)
367 : pinctrl_select_state(bri->pinctrl, bri->pins_gpio);
368 :
369 : /*
370 : * if there is incomplete or no recovery information, see if generic
371 : * GPIO recovery is available
372 : */
373 0 : if (!bri->scl_gpiod) {
374 : gpiod = devm_gpiod_get(dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN);
375 : if (PTR_ERR(gpiod) == -EPROBE_DEFER) {
376 : ret = -EPROBE_DEFER;
377 : goto cleanup_pinctrl_state;
378 : }
379 : if (!IS_ERR(gpiod)) {
380 : bri->scl_gpiod = gpiod;
381 : bri->recover_bus = i2c_generic_scl_recovery;
382 : dev_info(dev, "using generic GPIOs for recovery\n");
383 : }
384 : }
385 :
386 : /* SDA GPIOD line is optional, so we care about DEFER only */
387 0 : if (!bri->sda_gpiod) {
388 : /*
389 : * We have SCL. Pull SCL low and wait a bit so that SDA glitches
390 : * have no effect.
391 : */
392 0 : gpiod_direction_output(bri->scl_gpiod, 0);
393 0 : udelay(10);
394 0 : gpiod = devm_gpiod_get(dev, "sda", GPIOD_IN);
395 :
396 : /* Wait a bit in case of a SDA glitch, and then release SCL. */
397 0 : udelay(10);
398 0 : gpiod_direction_output(bri->scl_gpiod, 1);
399 :
400 : if (PTR_ERR(gpiod) == -EPROBE_DEFER) {
401 : ret = -EPROBE_DEFER;
402 : goto cleanup_pinctrl_state;
403 : }
404 : if (!IS_ERR(gpiod))
405 : bri->sda_gpiod = gpiod;
406 : }
407 :
408 : cleanup_pinctrl_state:
409 : /* change the state of the pins back to their default state */
410 0 : if (bri->pinctrl)
411 : pinctrl_select_state(bri->pinctrl, bri->pins_default);
412 :
413 : return ret;
414 : }
415 :
416 : static int i2c_gpio_init_recovery(struct i2c_adapter *adap)
417 : {
418 0 : i2c_gpio_init_pinctrl_recovery(adap);
419 0 : return i2c_gpio_init_generic_recovery(adap);
420 : }
421 :
422 0 : static int i2c_init_recovery(struct i2c_adapter *adap)
423 : {
424 0 : struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
425 0 : bool is_error_level = true;
426 : char *err_str;
427 :
428 0 : if (!bri)
429 : return 0;
430 :
431 0 : if (i2c_gpio_init_recovery(adap) == -EPROBE_DEFER)
432 : return -EPROBE_DEFER;
433 :
434 0 : if (!bri->recover_bus) {
435 : err_str = "no suitable method provided";
436 : is_error_level = false;
437 : goto err;
438 : }
439 :
440 0 : if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) {
441 0 : bri->get_scl = get_scl_gpio_value;
442 0 : bri->set_scl = set_scl_gpio_value;
443 0 : if (bri->sda_gpiod) {
444 0 : bri->get_sda = get_sda_gpio_value;
445 : /* FIXME: add proper flag instead of '0' once available */
446 0 : if (gpiod_get_direction(bri->sda_gpiod) == 0)
447 : bri->set_sda = set_sda_gpio_value;
448 : }
449 0 : } else if (bri->recover_bus == i2c_generic_scl_recovery) {
450 : /* Generic SCL recovery */
451 0 : if (!bri->set_scl || !bri->get_scl) {
452 : err_str = "no {get|set}_scl() found";
453 : goto err;
454 : }
455 0 : if (!bri->set_sda && !bri->get_sda) {
456 : err_str = "either get_sda() or set_sda() needed";
457 : goto err;
458 : }
459 : }
460 :
461 : return 0;
462 : err:
463 0 : if (is_error_level)
464 0 : dev_err(&adap->dev, "Not using recovery: %s\n", err_str);
465 : else
466 : dev_dbg(&adap->dev, "Not using recovery: %s\n", err_str);
467 0 : adap->bus_recovery_info = NULL;
468 :
469 0 : return -EINVAL;
470 : }
471 :
472 0 : static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client)
473 : {
474 0 : struct i2c_adapter *adap = client->adapter;
475 : unsigned int irq;
476 :
477 0 : if (!adap->host_notify_domain)
478 : return -ENXIO;
479 :
480 0 : if (client->flags & I2C_CLIENT_TEN)
481 : return -EINVAL;
482 :
483 0 : irq = irq_create_mapping(adap->host_notify_domain, client->addr);
484 :
485 0 : return irq > 0 ? irq : -ENXIO;
486 : }
487 :
488 0 : static int i2c_device_probe(struct device *dev)
489 : {
490 0 : struct i2c_client *client = i2c_verify_client(dev);
491 : struct i2c_driver *driver;
492 : bool do_power_on;
493 : int status;
494 :
495 0 : if (!client)
496 : return 0;
497 :
498 0 : client->irq = client->init_irq;
499 :
500 0 : if (!client->irq) {
501 0 : int irq = -ENOENT;
502 :
503 0 : if (client->flags & I2C_CLIENT_HOST_NOTIFY) {
504 : dev_dbg(dev, "Using Host Notify IRQ\n");
505 : /* Keep adapter active when Host Notify is required */
506 0 : pm_runtime_get_sync(&client->adapter->dev);
507 0 : irq = i2c_smbus_host_notify_to_irq(client);
508 0 : } else if (dev->of_node) {
509 0 : irq = of_irq_get_byname(dev->of_node, "irq");
510 : if (irq == -EINVAL || irq == -ENODATA)
511 : irq = of_irq_get(dev->of_node, 0);
512 : } else if (ACPI_COMPANION(dev)) {
513 : bool wake_capable;
514 :
515 : irq = i2c_acpi_get_irq(client, &wake_capable);
516 : if (irq > 0 && wake_capable)
517 : client->flags |= I2C_CLIENT_WAKE;
518 : }
519 0 : if (irq == -EPROBE_DEFER) {
520 : status = irq;
521 : goto put_sync_adapter;
522 : }
523 :
524 0 : if (irq < 0)
525 0 : irq = 0;
526 :
527 0 : client->irq = irq;
528 : }
529 :
530 0 : driver = to_i2c_driver(dev->driver);
531 :
532 : /*
533 : * An I2C ID table is not mandatory, if and only if, a suitable OF
534 : * or ACPI ID table is supplied for the probing device.
535 : */
536 0 : if (!driver->id_table &&
537 : !acpi_driver_match_device(dev, dev->driver) &&
538 : !i2c_of_match_device(dev->driver->of_match_table, client)) {
539 : status = -ENODEV;
540 : goto put_sync_adapter;
541 : }
542 :
543 0 : if (client->flags & I2C_CLIENT_WAKE) {
544 : int wakeirq;
545 :
546 0 : wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
547 : if (wakeirq == -EPROBE_DEFER) {
548 : status = wakeirq;
549 : goto put_sync_adapter;
550 : }
551 :
552 0 : device_init_wakeup(&client->dev, true);
553 :
554 : if (wakeirq > 0 && wakeirq != client->irq)
555 : status = dev_pm_set_dedicated_wake_irq(dev, wakeirq);
556 0 : else if (client->irq > 0)
557 0 : status = dev_pm_set_wake_irq(dev, client->irq);
558 : else
559 : status = 0;
560 :
561 0 : if (status)
562 0 : dev_warn(&client->dev, "failed to set up wakeup irq\n");
563 : }
564 :
565 : dev_dbg(dev, "probe\n");
566 :
567 0 : status = of_clk_set_defaults(dev->of_node, false);
568 : if (status < 0)
569 : goto err_clear_wakeup_irq;
570 :
571 0 : do_power_on = !i2c_acpi_waive_d0_probe(dev);
572 0 : status = dev_pm_domain_attach(&client->dev, do_power_on);
573 0 : if (status)
574 : goto err_clear_wakeup_irq;
575 :
576 0 : client->devres_group_id = devres_open_group(&client->dev, NULL,
577 : GFP_KERNEL);
578 0 : if (!client->devres_group_id) {
579 : status = -ENOMEM;
580 : goto err_detach_pm_domain;
581 : }
582 :
583 0 : if (driver->probe)
584 0 : status = driver->probe(client);
585 : else
586 : status = -EINVAL;
587 :
588 : /*
589 : * Note that we are not closing the devres group opened above so
590 : * even resources that were attached to the device after probe is
591 : * run are released when i2c_device_remove() is executed. This is
592 : * needed as some drivers would allocate additional resources,
593 : * for example when updating firmware.
594 : */
595 :
596 0 : if (status)
597 : goto err_release_driver_resources;
598 :
599 : return 0;
600 :
601 : err_release_driver_resources:
602 0 : devres_release_group(&client->dev, client->devres_group_id);
603 : err_detach_pm_domain:
604 0 : dev_pm_domain_detach(&client->dev, do_power_on);
605 : err_clear_wakeup_irq:
606 0 : dev_pm_clear_wake_irq(&client->dev);
607 0 : device_init_wakeup(&client->dev, false);
608 : put_sync_adapter:
609 0 : if (client->flags & I2C_CLIENT_HOST_NOTIFY)
610 0 : pm_runtime_put_sync(&client->adapter->dev);
611 :
612 : return status;
613 : }
614 :
615 0 : static void i2c_device_remove(struct device *dev)
616 : {
617 0 : struct i2c_client *client = to_i2c_client(dev);
618 : struct i2c_driver *driver;
619 :
620 0 : driver = to_i2c_driver(dev->driver);
621 0 : if (driver->remove) {
622 : dev_dbg(dev, "remove\n");
623 :
624 0 : driver->remove(client);
625 : }
626 :
627 0 : devres_release_group(&client->dev, client->devres_group_id);
628 :
629 0 : dev_pm_domain_detach(&client->dev, true);
630 :
631 0 : dev_pm_clear_wake_irq(&client->dev);
632 0 : device_init_wakeup(&client->dev, false);
633 :
634 0 : client->irq = 0;
635 0 : if (client->flags & I2C_CLIENT_HOST_NOTIFY)
636 0 : pm_runtime_put(&client->adapter->dev);
637 0 : }
638 :
639 0 : static void i2c_device_shutdown(struct device *dev)
640 : {
641 0 : struct i2c_client *client = i2c_verify_client(dev);
642 : struct i2c_driver *driver;
643 :
644 0 : if (!client || !dev->driver)
645 : return;
646 0 : driver = to_i2c_driver(dev->driver);
647 0 : if (driver->shutdown)
648 0 : driver->shutdown(client);
649 0 : else if (client->irq > 0)
650 0 : disable_irq(client->irq);
651 : }
652 :
653 0 : static void i2c_client_dev_release(struct device *dev)
654 : {
655 0 : kfree(to_i2c_client(dev));
656 0 : }
657 :
658 : static ssize_t
659 0 : name_show(struct device *dev, struct device_attribute *attr, char *buf)
660 : {
661 0 : return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?
662 0 : to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);
663 : }
664 : static DEVICE_ATTR_RO(name);
665 :
666 : static ssize_t
667 0 : modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
668 : {
669 0 : struct i2c_client *client = to_i2c_client(dev);
670 : int len;
671 :
672 0 : len = of_device_modalias(dev, buf, PAGE_SIZE);
673 : if (len != -ENODEV)
674 : return len;
675 :
676 0 : len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
677 : if (len != -ENODEV)
678 : return len;
679 :
680 0 : return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
681 : }
682 : static DEVICE_ATTR_RO(modalias);
683 :
684 : static struct attribute *i2c_dev_attrs[] = {
685 : &dev_attr_name.attr,
686 : /* modalias helps coldplug: modprobe $(cat .../modalias) */
687 : &dev_attr_modalias.attr,
688 : NULL
689 : };
690 : ATTRIBUTE_GROUPS(i2c_dev);
691 :
692 : struct bus_type i2c_bus_type = {
693 : .name = "i2c",
694 : .match = i2c_device_match,
695 : .probe = i2c_device_probe,
696 : .remove = i2c_device_remove,
697 : .shutdown = i2c_device_shutdown,
698 : };
699 : EXPORT_SYMBOL_GPL(i2c_bus_type);
700 :
701 : struct device_type i2c_client_type = {
702 : .groups = i2c_dev_groups,
703 : .uevent = i2c_device_uevent,
704 : .release = i2c_client_dev_release,
705 : };
706 : EXPORT_SYMBOL_GPL(i2c_client_type);
707 :
708 :
709 : /**
710 : * i2c_verify_client - return parameter as i2c_client, or NULL
711 : * @dev: device, probably from some driver model iterator
712 : *
713 : * When traversing the driver model tree, perhaps using driver model
714 : * iterators like @device_for_each_child(), you can't assume very much
715 : * about the nodes you find. Use this function to avoid oopses caused
716 : * by wrongly treating some non-I2C device as an i2c_client.
717 : */
718 0 : struct i2c_client *i2c_verify_client(struct device *dev)
719 : {
720 0 : return (dev->type == &i2c_client_type)
721 0 : ? to_i2c_client(dev)
722 0 : : NULL;
723 : }
724 : EXPORT_SYMBOL(i2c_verify_client);
725 :
726 :
727 : /* Return a unique address which takes the flags of the client into account */
728 : static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client)
729 : {
730 0 : unsigned short addr = client->addr;
731 :
732 : /* For some client flags, add an arbitrary offset to avoid collisions */
733 0 : if (client->flags & I2C_CLIENT_TEN)
734 0 : addr |= I2C_ADDR_OFFSET_TEN_BIT;
735 :
736 0 : if (client->flags & I2C_CLIENT_SLAVE)
737 0 : addr |= I2C_ADDR_OFFSET_SLAVE;
738 :
739 : return addr;
740 : }
741 :
742 : /* This is a permissive address validity check, I2C address map constraints
743 : * are purposely not enforced, except for the general call address. */
744 : static int i2c_check_addr_validity(unsigned int addr, unsigned short flags)
745 : {
746 0 : if (flags & I2C_CLIENT_TEN) {
747 : /* 10-bit address, all values are valid */
748 0 : if (addr > 0x3ff)
749 : return -EINVAL;
750 : } else {
751 : /* 7-bit address, reject the general call address */
752 0 : if (addr == 0x00 || addr > 0x7f)
753 : return -EINVAL;
754 : }
755 : return 0;
756 : }
757 :
758 : /* And this is a strict address validity check, used when probing. If a
759 : * device uses a reserved address, then it shouldn't be probed. 7-bit
760 : * addressing is assumed, 10-bit address devices are rare and should be
761 : * explicitly enumerated. */
762 0 : int i2c_check_7bit_addr_validity_strict(unsigned short addr)
763 : {
764 : /*
765 : * Reserved addresses per I2C specification:
766 : * 0x00 General call address / START byte
767 : * 0x01 CBUS address
768 : * 0x02 Reserved for different bus format
769 : * 0x03 Reserved for future purposes
770 : * 0x04-0x07 Hs-mode master code
771 : * 0x78-0x7b 10-bit slave addressing
772 : * 0x7c-0x7f Reserved for future purposes
773 : */
774 0 : if (addr < 0x08 || addr > 0x77)
775 : return -EINVAL;
776 0 : return 0;
777 : }
778 :
779 : static int __i2c_check_addr_busy(struct device *dev, void *addrp)
780 : {
781 0 : struct i2c_client *client = i2c_verify_client(dev);
782 0 : int addr = *(int *)addrp;
783 :
784 0 : if (client && i2c_encode_flags_to_addr(client) == addr)
785 : return -EBUSY;
786 : return 0;
787 : }
788 :
789 : /* walk up mux tree */
790 : static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)
791 : {
792 : struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
793 : int result;
794 :
795 : result = device_for_each_child(&adapter->dev, &addr,
796 : __i2c_check_addr_busy);
797 :
798 : if (!result && parent)
799 : result = i2c_check_mux_parents(parent, addr);
800 :
801 : return result;
802 : }
803 :
804 : /* recurse down mux tree */
805 0 : static int i2c_check_mux_children(struct device *dev, void *addrp)
806 : {
807 : int result;
808 :
809 0 : if (dev->type == &i2c_adapter_type)
810 0 : result = device_for_each_child(dev, addrp,
811 : i2c_check_mux_children);
812 : else
813 : result = __i2c_check_addr_busy(dev, addrp);
814 :
815 0 : return result;
816 : }
817 :
818 : static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
819 : {
820 0 : struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
821 0 : int result = 0;
822 :
823 : if (parent)
824 : result = i2c_check_mux_parents(parent, addr);
825 :
826 : if (!result)
827 0 : result = device_for_each_child(&adapter->dev, &addr,
828 : i2c_check_mux_children);
829 :
830 : return result;
831 : }
832 :
833 : /**
834 : * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment
835 : * @adapter: Target I2C bus segment
836 : * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
837 : * locks only this branch in the adapter tree
838 : */
839 0 : static void i2c_adapter_lock_bus(struct i2c_adapter *adapter,
840 : unsigned int flags)
841 : {
842 0 : rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter));
843 0 : }
844 :
845 : /**
846 : * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment
847 : * @adapter: Target I2C bus segment
848 : * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT
849 : * trylocks only this branch in the adapter tree
850 : */
851 0 : static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter,
852 : unsigned int flags)
853 : {
854 0 : return rt_mutex_trylock(&adapter->bus_lock);
855 : }
856 :
857 : /**
858 : * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment
859 : * @adapter: Target I2C bus segment
860 : * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
861 : * unlocks only this branch in the adapter tree
862 : */
863 0 : static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter,
864 : unsigned int flags)
865 : {
866 0 : rt_mutex_unlock(&adapter->bus_lock);
867 0 : }
868 :
869 0 : static void i2c_dev_set_name(struct i2c_adapter *adap,
870 : struct i2c_client *client,
871 : struct i2c_board_info const *info)
872 : {
873 0 : struct acpi_device *adev = ACPI_COMPANION(&client->dev);
874 :
875 0 : if (info && info->dev_name) {
876 0 : dev_set_name(&client->dev, "i2c-%s", info->dev_name);
877 0 : return;
878 : }
879 :
880 : if (adev) {
881 : dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev));
882 : return;
883 : }
884 :
885 0 : dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
886 0 : i2c_encode_flags_to_addr(client));
887 : }
888 :
889 0 : int i2c_dev_irq_from_resources(const struct resource *resources,
890 : unsigned int num_resources)
891 : {
892 : struct irq_data *irqd;
893 : int i;
894 :
895 0 : for (i = 0; i < num_resources; i++) {
896 0 : const struct resource *r = &resources[i];
897 :
898 0 : if (resource_type(r) != IORESOURCE_IRQ)
899 0 : continue;
900 :
901 0 : if (r->flags & IORESOURCE_BITS) {
902 0 : irqd = irq_get_irq_data(r->start);
903 0 : if (!irqd)
904 : break;
905 :
906 0 : irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
907 : }
908 :
909 0 : return r->start;
910 : }
911 :
912 : return 0;
913 : }
914 :
915 : /**
916 : * i2c_new_client_device - instantiate an i2c device
917 : * @adap: the adapter managing the device
918 : * @info: describes one I2C device; bus_num is ignored
919 : * Context: can sleep
920 : *
921 : * Create an i2c device. Binding is handled through driver model
922 : * probe()/remove() methods. A driver may be bound to this device when we
923 : * return from this function, or any later moment (e.g. maybe hotplugging will
924 : * load the driver module). This call is not appropriate for use by mainboard
925 : * initialization logic, which usually runs during an arch_initcall() long
926 : * before any i2c_adapter could exist.
927 : *
928 : * This returns the new i2c client, which may be saved for later use with
929 : * i2c_unregister_device(); or an ERR_PTR to describe the error.
930 : */
931 : struct i2c_client *
932 0 : i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
933 : {
934 : struct i2c_client *client;
935 : int status;
936 :
937 0 : client = kzalloc(sizeof *client, GFP_KERNEL);
938 0 : if (!client)
939 : return ERR_PTR(-ENOMEM);
940 :
941 0 : client->adapter = adap;
942 :
943 0 : client->dev.platform_data = info->platform_data;
944 0 : client->flags = info->flags;
945 0 : client->addr = info->addr;
946 :
947 0 : client->init_irq = info->irq;
948 0 : if (!client->init_irq)
949 0 : client->init_irq = i2c_dev_irq_from_resources(info->resources,
950 : info->num_resources);
951 :
952 0 : strscpy(client->name, info->type, sizeof(client->name));
953 :
954 0 : status = i2c_check_addr_validity(client->addr, client->flags);
955 0 : if (status) {
956 0 : dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n",
957 : client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr);
958 0 : goto out_err_silent;
959 : }
960 :
961 : /* Check for address business */
962 0 : status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client));
963 0 : if (status)
964 : goto out_err;
965 :
966 0 : client->dev.parent = &client->adapter->dev;
967 0 : client->dev.bus = &i2c_bus_type;
968 0 : client->dev.type = &i2c_client_type;
969 0 : client->dev.of_node = of_node_get(info->of_node);
970 0 : client->dev.fwnode = info->fwnode;
971 :
972 0 : device_enable_async_suspend(&client->dev);
973 0 : i2c_dev_set_name(adap, client, info);
974 :
975 0 : if (info->swnode) {
976 0 : status = device_add_software_node(&client->dev, info->swnode);
977 0 : if (status) {
978 0 : dev_err(&adap->dev,
979 : "Failed to add software node to client %s: %d\n",
980 : client->name, status);
981 0 : goto out_err_put_of_node;
982 : }
983 : }
984 :
985 0 : status = device_register(&client->dev);
986 0 : if (status)
987 : goto out_remove_swnode;
988 :
989 : dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
990 : client->name, dev_name(&client->dev));
991 :
992 : return client;
993 :
994 : out_remove_swnode:
995 0 : device_remove_software_node(&client->dev);
996 : out_err_put_of_node:
997 0 : of_node_put(info->of_node);
998 : out_err:
999 0 : dev_err(&adap->dev,
1000 : "Failed to register i2c client %s at 0x%02x (%d)\n",
1001 : client->name, client->addr, status);
1002 : out_err_silent:
1003 0 : kfree(client);
1004 0 : return ERR_PTR(status);
1005 : }
1006 : EXPORT_SYMBOL_GPL(i2c_new_client_device);
1007 :
1008 : /**
1009 : * i2c_unregister_device - reverse effect of i2c_new_*_device()
1010 : * @client: value returned from i2c_new_*_device()
1011 : * Context: can sleep
1012 : */
1013 0 : void i2c_unregister_device(struct i2c_client *client)
1014 : {
1015 0 : if (IS_ERR_OR_NULL(client))
1016 : return;
1017 :
1018 : if (client->dev.of_node) {
1019 : of_node_clear_flag(client->dev.of_node, OF_POPULATED);
1020 : of_node_put(client->dev.of_node);
1021 : }
1022 :
1023 : if (ACPI_COMPANION(&client->dev))
1024 : acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev));
1025 0 : device_remove_software_node(&client->dev);
1026 0 : device_unregister(&client->dev);
1027 : }
1028 : EXPORT_SYMBOL_GPL(i2c_unregister_device);
1029 :
1030 : /**
1031 : * i2c_find_device_by_fwnode() - find an i2c_client for the fwnode
1032 : * @fwnode: &struct fwnode_handle corresponding to the &struct i2c_client
1033 : *
1034 : * Look up and return the &struct i2c_client corresponding to the @fwnode.
1035 : * If no client can be found, or @fwnode is NULL, this returns NULL.
1036 : *
1037 : * The user must call put_device(&client->dev) once done with the i2c client.
1038 : */
1039 0 : struct i2c_client *i2c_find_device_by_fwnode(struct fwnode_handle *fwnode)
1040 : {
1041 : struct i2c_client *client;
1042 : struct device *dev;
1043 :
1044 0 : if (!fwnode)
1045 : return NULL;
1046 :
1047 0 : dev = bus_find_device_by_fwnode(&i2c_bus_type, fwnode);
1048 0 : if (!dev)
1049 : return NULL;
1050 :
1051 0 : client = i2c_verify_client(dev);
1052 0 : if (!client)
1053 0 : put_device(dev);
1054 :
1055 : return client;
1056 : }
1057 : EXPORT_SYMBOL(i2c_find_device_by_fwnode);
1058 :
1059 :
1060 : static const struct i2c_device_id dummy_id[] = {
1061 : { "dummy", 0 },
1062 : { },
1063 : };
1064 :
1065 0 : static int dummy_probe(struct i2c_client *client)
1066 : {
1067 0 : return 0;
1068 : }
1069 :
1070 : static struct i2c_driver dummy_driver = {
1071 : .driver.name = "dummy",
1072 : .probe = dummy_probe,
1073 : .id_table = dummy_id,
1074 : };
1075 :
1076 : /**
1077 : * i2c_new_dummy_device - return a new i2c device bound to a dummy driver
1078 : * @adapter: the adapter managing the device
1079 : * @address: seven bit address to be used
1080 : * Context: can sleep
1081 : *
1082 : * This returns an I2C client bound to the "dummy" driver, intended for use
1083 : * with devices that consume multiple addresses. Examples of such chips
1084 : * include various EEPROMS (like 24c04 and 24c08 models).
1085 : *
1086 : * These dummy devices have two main uses. First, most I2C and SMBus calls
1087 : * except i2c_transfer() need a client handle; the dummy will be that handle.
1088 : * And second, this prevents the specified address from being bound to a
1089 : * different driver.
1090 : *
1091 : * This returns the new i2c client, which should be saved for later use with
1092 : * i2c_unregister_device(); or an ERR_PTR to describe the error.
1093 : */
1094 0 : struct i2c_client *i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address)
1095 : {
1096 0 : struct i2c_board_info info = {
1097 : I2C_BOARD_INFO("dummy", address),
1098 : };
1099 :
1100 0 : return i2c_new_client_device(adapter, &info);
1101 : }
1102 : EXPORT_SYMBOL_GPL(i2c_new_dummy_device);
1103 :
1104 0 : static void devm_i2c_release_dummy(void *client)
1105 : {
1106 0 : i2c_unregister_device(client);
1107 0 : }
1108 :
1109 : /**
1110 : * devm_i2c_new_dummy_device - return a new i2c device bound to a dummy driver
1111 : * @dev: device the managed resource is bound to
1112 : * @adapter: the adapter managing the device
1113 : * @address: seven bit address to be used
1114 : * Context: can sleep
1115 : *
1116 : * This is the device-managed version of @i2c_new_dummy_device. It returns the
1117 : * new i2c client or an ERR_PTR in case of an error.
1118 : */
1119 0 : struct i2c_client *devm_i2c_new_dummy_device(struct device *dev,
1120 : struct i2c_adapter *adapter,
1121 : u16 address)
1122 : {
1123 : struct i2c_client *client;
1124 : int ret;
1125 :
1126 0 : client = i2c_new_dummy_device(adapter, address);
1127 0 : if (IS_ERR(client))
1128 : return client;
1129 :
1130 0 : ret = devm_add_action_or_reset(dev, devm_i2c_release_dummy, client);
1131 0 : if (ret)
1132 0 : return ERR_PTR(ret);
1133 :
1134 : return client;
1135 : }
1136 : EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device);
1137 :
1138 : /**
1139 : * i2c_new_ancillary_device - Helper to get the instantiated secondary address
1140 : * and create the associated device
1141 : * @client: Handle to the primary client
1142 : * @name: Handle to specify which secondary address to get
1143 : * @default_addr: Used as a fallback if no secondary address was specified
1144 : * Context: can sleep
1145 : *
1146 : * I2C clients can be composed of multiple I2C slaves bound together in a single
1147 : * component. The I2C client driver then binds to the master I2C slave and needs
1148 : * to create I2C dummy clients to communicate with all the other slaves.
1149 : *
1150 : * This function creates and returns an I2C dummy client whose I2C address is
1151 : * retrieved from the platform firmware based on the given slave name. If no
1152 : * address is specified by the firmware default_addr is used.
1153 : *
1154 : * On DT-based platforms the address is retrieved from the "reg" property entry
1155 : * cell whose "reg-names" value matches the slave name.
1156 : *
1157 : * This returns the new i2c client, which should be saved for later use with
1158 : * i2c_unregister_device(); or an ERR_PTR to describe the error.
1159 : */
1160 0 : struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client,
1161 : const char *name,
1162 : u16 default_addr)
1163 : {
1164 0 : struct device_node *np = client->dev.of_node;
1165 0 : u32 addr = default_addr;
1166 : int i;
1167 :
1168 : if (np) {
1169 : i = of_property_match_string(np, "reg-names", name);
1170 : if (i >= 0)
1171 : of_property_read_u32_index(np, "reg", i, &addr);
1172 : }
1173 :
1174 : dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr);
1175 0 : return i2c_new_dummy_device(client->adapter, addr);
1176 : }
1177 : EXPORT_SYMBOL_GPL(i2c_new_ancillary_device);
1178 :
1179 : /* ------------------------------------------------------------------------- */
1180 :
1181 : /* I2C bus adapters -- one roots each I2C or SMBUS segment */
1182 :
1183 0 : static void i2c_adapter_dev_release(struct device *dev)
1184 : {
1185 0 : struct i2c_adapter *adap = to_i2c_adapter(dev);
1186 0 : complete(&adap->dev_released);
1187 0 : }
1188 :
1189 0 : unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
1190 : {
1191 0 : unsigned int depth = 0;
1192 :
1193 0 : while ((adapter = i2c_parent_is_i2c_adapter(adapter)))
1194 : depth++;
1195 :
1196 0 : WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES,
1197 : "adapter depth exceeds lockdep subclass limit\n");
1198 :
1199 0 : return depth;
1200 : }
1201 : EXPORT_SYMBOL_GPL(i2c_adapter_depth);
1202 :
1203 : /*
1204 : * Let users instantiate I2C devices through sysfs. This can be used when
1205 : * platform initialization code doesn't contain the proper data for
1206 : * whatever reason. Also useful for drivers that do device detection and
1207 : * detection fails, either because the device uses an unexpected address,
1208 : * or this is a compatible device with different ID register values.
1209 : *
1210 : * Parameter checking may look overzealous, but we really don't want
1211 : * the user to provide incorrect parameters.
1212 : */
1213 : static ssize_t
1214 0 : new_device_store(struct device *dev, struct device_attribute *attr,
1215 : const char *buf, size_t count)
1216 : {
1217 0 : struct i2c_adapter *adap = to_i2c_adapter(dev);
1218 : struct i2c_board_info info;
1219 : struct i2c_client *client;
1220 : char *blank, end;
1221 : int res;
1222 :
1223 0 : memset(&info, 0, sizeof(struct i2c_board_info));
1224 :
1225 0 : blank = strchr(buf, ' ');
1226 0 : if (!blank) {
1227 0 : dev_err(dev, "%s: Missing parameters\n", "new_device");
1228 0 : return -EINVAL;
1229 : }
1230 0 : if (blank - buf > I2C_NAME_SIZE - 1) {
1231 0 : dev_err(dev, "%s: Invalid device name\n", "new_device");
1232 0 : return -EINVAL;
1233 : }
1234 0 : memcpy(info.type, buf, blank - buf);
1235 :
1236 : /* Parse remaining parameters, reject extra parameters */
1237 0 : res = sscanf(++blank, "%hi%c", &info.addr, &end);
1238 0 : if (res < 1) {
1239 0 : dev_err(dev, "%s: Can't parse I2C address\n", "new_device");
1240 0 : return -EINVAL;
1241 : }
1242 0 : if (res > 1 && end != '\n') {
1243 0 : dev_err(dev, "%s: Extra parameters\n", "new_device");
1244 0 : return -EINVAL;
1245 : }
1246 :
1247 0 : if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) {
1248 0 : info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT;
1249 0 : info.flags |= I2C_CLIENT_TEN;
1250 : }
1251 :
1252 0 : if (info.addr & I2C_ADDR_OFFSET_SLAVE) {
1253 0 : info.addr &= ~I2C_ADDR_OFFSET_SLAVE;
1254 0 : info.flags |= I2C_CLIENT_SLAVE;
1255 : }
1256 :
1257 0 : client = i2c_new_client_device(adap, &info);
1258 0 : if (IS_ERR(client))
1259 0 : return PTR_ERR(client);
1260 :
1261 : /* Keep track of the added device */
1262 0 : mutex_lock(&adap->userspace_clients_lock);
1263 0 : list_add_tail(&client->detected, &adap->userspace_clients);
1264 0 : mutex_unlock(&adap->userspace_clients_lock);
1265 0 : dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
1266 : info.type, info.addr);
1267 :
1268 0 : return count;
1269 : }
1270 : static DEVICE_ATTR_WO(new_device);
1271 :
1272 : /*
1273 : * And of course let the users delete the devices they instantiated, if
1274 : * they got it wrong. This interface can only be used to delete devices
1275 : * instantiated by i2c_sysfs_new_device above. This guarantees that we
1276 : * don't delete devices to which some kernel code still has references.
1277 : *
1278 : * Parameter checking may look overzealous, but we really don't want
1279 : * the user to delete the wrong device.
1280 : */
1281 : static ssize_t
1282 0 : delete_device_store(struct device *dev, struct device_attribute *attr,
1283 : const char *buf, size_t count)
1284 : {
1285 0 : struct i2c_adapter *adap = to_i2c_adapter(dev);
1286 : struct i2c_client *client, *next;
1287 : unsigned short addr;
1288 : char end;
1289 : int res;
1290 :
1291 : /* Parse parameters, reject extra parameters */
1292 0 : res = sscanf(buf, "%hi%c", &addr, &end);
1293 0 : if (res < 1) {
1294 0 : dev_err(dev, "%s: Can't parse I2C address\n", "delete_device");
1295 0 : return -EINVAL;
1296 : }
1297 0 : if (res > 1 && end != '\n') {
1298 0 : dev_err(dev, "%s: Extra parameters\n", "delete_device");
1299 0 : return -EINVAL;
1300 : }
1301 :
1302 : /* Make sure the device was added through sysfs */
1303 0 : res = -ENOENT;
1304 0 : mutex_lock_nested(&adap->userspace_clients_lock,
1305 : i2c_adapter_depth(adap));
1306 0 : list_for_each_entry_safe(client, next, &adap->userspace_clients,
1307 : detected) {
1308 0 : if (i2c_encode_flags_to_addr(client) == addr) {
1309 0 : dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",
1310 : "delete_device", client->name, client->addr);
1311 :
1312 0 : list_del(&client->detected);
1313 0 : i2c_unregister_device(client);
1314 0 : res = count;
1315 0 : break;
1316 : }
1317 : }
1318 0 : mutex_unlock(&adap->userspace_clients_lock);
1319 :
1320 0 : if (res < 0)
1321 0 : dev_err(dev, "%s: Can't find device in list\n",
1322 : "delete_device");
1323 0 : return res;
1324 : }
1325 : static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL,
1326 : delete_device_store);
1327 :
1328 : static struct attribute *i2c_adapter_attrs[] = {
1329 : &dev_attr_name.attr,
1330 : &dev_attr_new_device.attr,
1331 : &dev_attr_delete_device.attr,
1332 : NULL
1333 : };
1334 : ATTRIBUTE_GROUPS(i2c_adapter);
1335 :
1336 : struct device_type i2c_adapter_type = {
1337 : .groups = i2c_adapter_groups,
1338 : .release = i2c_adapter_dev_release,
1339 : };
1340 : EXPORT_SYMBOL_GPL(i2c_adapter_type);
1341 :
1342 : /**
1343 : * i2c_verify_adapter - return parameter as i2c_adapter or NULL
1344 : * @dev: device, probably from some driver model iterator
1345 : *
1346 : * When traversing the driver model tree, perhaps using driver model
1347 : * iterators like @device_for_each_child(), you can't assume very much
1348 : * about the nodes you find. Use this function to avoid oopses caused
1349 : * by wrongly treating some non-I2C device as an i2c_adapter.
1350 : */
1351 0 : struct i2c_adapter *i2c_verify_adapter(struct device *dev)
1352 : {
1353 0 : return (dev->type == &i2c_adapter_type)
1354 0 : ? to_i2c_adapter(dev)
1355 0 : : NULL;
1356 : }
1357 : EXPORT_SYMBOL(i2c_verify_adapter);
1358 :
1359 : #ifdef CONFIG_I2C_COMPAT
1360 : static struct class_compat *i2c_adapter_compat_class;
1361 : #endif
1362 :
1363 0 : static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
1364 : {
1365 : struct i2c_devinfo *devinfo;
1366 :
1367 0 : down_read(&__i2c_board_lock);
1368 0 : list_for_each_entry(devinfo, &__i2c_board_list, list) {
1369 0 : if (devinfo->busnum == adapter->nr &&
1370 0 : IS_ERR(i2c_new_client_device(adapter, &devinfo->board_info)))
1371 0 : dev_err(&adapter->dev,
1372 : "Can't create device at 0x%02x\n",
1373 : devinfo->board_info.addr);
1374 : }
1375 0 : up_read(&__i2c_board_lock);
1376 0 : }
1377 :
1378 : static int i2c_do_add_adapter(struct i2c_driver *driver,
1379 : struct i2c_adapter *adap)
1380 : {
1381 : /* Detect supported devices on that bus, and instantiate them */
1382 0 : i2c_detect(adap, driver);
1383 :
1384 : return 0;
1385 : }
1386 :
1387 0 : static int __process_new_adapter(struct device_driver *d, void *data)
1388 : {
1389 0 : return i2c_do_add_adapter(to_i2c_driver(d), data);
1390 : }
1391 :
1392 : static const struct i2c_lock_operations i2c_adapter_lock_ops = {
1393 : .lock_bus = i2c_adapter_lock_bus,
1394 : .trylock_bus = i2c_adapter_trylock_bus,
1395 : .unlock_bus = i2c_adapter_unlock_bus,
1396 : };
1397 :
1398 0 : static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap)
1399 : {
1400 0 : struct irq_domain *domain = adap->host_notify_domain;
1401 : irq_hw_number_t hwirq;
1402 :
1403 0 : if (!domain)
1404 : return;
1405 :
1406 0 : for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++)
1407 0 : irq_dispose_mapping(irq_find_mapping(domain, hwirq));
1408 :
1409 0 : irq_domain_remove(domain);
1410 0 : adap->host_notify_domain = NULL;
1411 : }
1412 :
1413 0 : static int i2c_host_notify_irq_map(struct irq_domain *h,
1414 : unsigned int virq,
1415 : irq_hw_number_t hw_irq_num)
1416 : {
1417 0 : irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
1418 :
1419 0 : return 0;
1420 : }
1421 :
1422 : static const struct irq_domain_ops i2c_host_notify_irq_ops = {
1423 : .map = i2c_host_notify_irq_map,
1424 : };
1425 :
1426 0 : static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap)
1427 : {
1428 : struct irq_domain *domain;
1429 :
1430 0 : if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY))
1431 : return 0;
1432 :
1433 0 : domain = irq_domain_create_linear(adap->dev.parent->fwnode,
1434 : I2C_ADDR_7BITS_COUNT,
1435 : &i2c_host_notify_irq_ops, adap);
1436 0 : if (!domain)
1437 : return -ENOMEM;
1438 :
1439 0 : adap->host_notify_domain = domain;
1440 :
1441 0 : return 0;
1442 : }
1443 :
1444 : /**
1445 : * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct
1446 : * I2C client.
1447 : * @adap: the adapter
1448 : * @addr: the I2C address of the notifying device
1449 : * Context: can't sleep
1450 : *
1451 : * Helper function to be called from an I2C bus driver's interrupt
1452 : * handler. It will schedule the Host Notify IRQ.
1453 : */
1454 0 : int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr)
1455 : {
1456 : int irq;
1457 :
1458 0 : if (!adap)
1459 : return -EINVAL;
1460 :
1461 0 : irq = irq_find_mapping(adap->host_notify_domain, addr);
1462 0 : if (irq <= 0)
1463 : return -ENXIO;
1464 :
1465 0 : generic_handle_irq_safe(irq);
1466 :
1467 0 : return 0;
1468 : }
1469 : EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify);
1470 :
1471 0 : static int i2c_register_adapter(struct i2c_adapter *adap)
1472 : {
1473 0 : int res = -EINVAL;
1474 :
1475 : /* Can't register until after driver model init */
1476 0 : if (WARN_ON(!is_registered)) {
1477 : res = -EAGAIN;
1478 : goto out_list;
1479 : }
1480 :
1481 : /* Sanity checks */
1482 0 : if (WARN(!adap->name[0], "i2c adapter has no name"))
1483 : goto out_list;
1484 :
1485 0 : if (!adap->algo) {
1486 0 : pr_err("adapter '%s': no algo supplied!\n", adap->name);
1487 0 : goto out_list;
1488 : }
1489 :
1490 0 : if (!adap->lock_ops)
1491 0 : adap->lock_ops = &i2c_adapter_lock_ops;
1492 :
1493 0 : adap->locked_flags = 0;
1494 0 : rt_mutex_init(&adap->bus_lock);
1495 0 : rt_mutex_init(&adap->mux_lock);
1496 0 : mutex_init(&adap->userspace_clients_lock);
1497 0 : INIT_LIST_HEAD(&adap->userspace_clients);
1498 :
1499 : /* Set default timeout to 1 second if not already set */
1500 0 : if (adap->timeout == 0)
1501 0 : adap->timeout = HZ;
1502 :
1503 : /* register soft irqs for Host Notify */
1504 0 : res = i2c_setup_host_notify_irq_domain(adap);
1505 0 : if (res) {
1506 0 : pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n",
1507 : adap->name, res);
1508 0 : goto out_list;
1509 : }
1510 :
1511 0 : dev_set_name(&adap->dev, "i2c-%d", adap->nr);
1512 0 : adap->dev.bus = &i2c_bus_type;
1513 0 : adap->dev.type = &i2c_adapter_type;
1514 0 : res = device_register(&adap->dev);
1515 0 : if (res) {
1516 0 : pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
1517 0 : goto out_list;
1518 : }
1519 :
1520 0 : res = i2c_setup_smbus_alert(adap);
1521 : if (res)
1522 : goto out_reg;
1523 :
1524 0 : device_enable_async_suspend(&adap->dev);
1525 0 : pm_runtime_no_callbacks(&adap->dev);
1526 0 : pm_suspend_ignore_children(&adap->dev, true);
1527 0 : pm_runtime_enable(&adap->dev);
1528 :
1529 0 : res = i2c_init_recovery(adap);
1530 0 : if (res == -EPROBE_DEFER)
1531 : goto out_reg;
1532 :
1533 : dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
1534 :
1535 : #ifdef CONFIG_I2C_COMPAT
1536 0 : res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev,
1537 : adap->dev.parent);
1538 0 : if (res)
1539 0 : dev_warn(&adap->dev,
1540 : "Failed to create compatibility class link\n");
1541 : #endif
1542 :
1543 : /* create pre-declared device nodes */
1544 0 : of_i2c_register_devices(adap);
1545 0 : i2c_acpi_install_space_handler(adap);
1546 0 : i2c_acpi_register_devices(adap);
1547 :
1548 0 : if (adap->nr < __i2c_first_dynamic_bus_num)
1549 0 : i2c_scan_static_board_info(adap);
1550 :
1551 : /* Notify drivers */
1552 0 : mutex_lock(&core_lock);
1553 0 : bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter);
1554 0 : mutex_unlock(&core_lock);
1555 :
1556 0 : return 0;
1557 :
1558 : out_reg:
1559 0 : init_completion(&adap->dev_released);
1560 0 : device_unregister(&adap->dev);
1561 0 : wait_for_completion(&adap->dev_released);
1562 : out_list:
1563 0 : mutex_lock(&core_lock);
1564 0 : idr_remove(&i2c_adapter_idr, adap->nr);
1565 0 : mutex_unlock(&core_lock);
1566 0 : return res;
1567 : }
1568 :
1569 : /**
1570 : * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1
1571 : * @adap: the adapter to register (with adap->nr initialized)
1572 : * Context: can sleep
1573 : *
1574 : * See i2c_add_numbered_adapter() for details.
1575 : */
1576 0 : static int __i2c_add_numbered_adapter(struct i2c_adapter *adap)
1577 : {
1578 : int id;
1579 :
1580 0 : mutex_lock(&core_lock);
1581 0 : id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL);
1582 0 : mutex_unlock(&core_lock);
1583 0 : if (WARN(id < 0, "couldn't get idr"))
1584 0 : return id == -ENOSPC ? -EBUSY : id;
1585 :
1586 0 : return i2c_register_adapter(adap);
1587 : }
1588 :
1589 : /**
1590 : * i2c_add_adapter - declare i2c adapter, use dynamic bus number
1591 : * @adapter: the adapter to add
1592 : * Context: can sleep
1593 : *
1594 : * This routine is used to declare an I2C adapter when its bus number
1595 : * doesn't matter or when its bus number is specified by an dt alias.
1596 : * Examples of bases when the bus number doesn't matter: I2C adapters
1597 : * dynamically added by USB links or PCI plugin cards.
1598 : *
1599 : * When this returns zero, a new bus number was allocated and stored
1600 : * in adap->nr, and the specified adapter became available for clients.
1601 : * Otherwise, a negative errno value is returned.
1602 : */
1603 0 : int i2c_add_adapter(struct i2c_adapter *adapter)
1604 : {
1605 0 : struct device *dev = &adapter->dev;
1606 : int id;
1607 :
1608 : if (dev->of_node) {
1609 : id = of_alias_get_id(dev->of_node, "i2c");
1610 : if (id >= 0) {
1611 : adapter->nr = id;
1612 : return __i2c_add_numbered_adapter(adapter);
1613 : }
1614 : }
1615 :
1616 0 : mutex_lock(&core_lock);
1617 0 : id = idr_alloc(&i2c_adapter_idr, adapter,
1618 : __i2c_first_dynamic_bus_num, 0, GFP_KERNEL);
1619 0 : mutex_unlock(&core_lock);
1620 0 : if (WARN(id < 0, "couldn't get idr"))
1621 : return id;
1622 :
1623 0 : adapter->nr = id;
1624 :
1625 0 : return i2c_register_adapter(adapter);
1626 : }
1627 : EXPORT_SYMBOL(i2c_add_adapter);
1628 :
1629 : /**
1630 : * i2c_add_numbered_adapter - declare i2c adapter, use static bus number
1631 : * @adap: the adapter to register (with adap->nr initialized)
1632 : * Context: can sleep
1633 : *
1634 : * This routine is used to declare an I2C adapter when its bus number
1635 : * matters. For example, use it for I2C adapters from system-on-chip CPUs,
1636 : * or otherwise built in to the system's mainboard, and where i2c_board_info
1637 : * is used to properly configure I2C devices.
1638 : *
1639 : * If the requested bus number is set to -1, then this function will behave
1640 : * identically to i2c_add_adapter, and will dynamically assign a bus number.
1641 : *
1642 : * If no devices have pre-been declared for this bus, then be sure to
1643 : * register the adapter before any dynamically allocated ones. Otherwise
1644 : * the required bus ID may not be available.
1645 : *
1646 : * When this returns zero, the specified adapter became available for
1647 : * clients using the bus number provided in adap->nr. Also, the table
1648 : * of I2C devices pre-declared using i2c_register_board_info() is scanned,
1649 : * and the appropriate driver model device nodes are created. Otherwise, a
1650 : * negative errno value is returned.
1651 : */
1652 0 : int i2c_add_numbered_adapter(struct i2c_adapter *adap)
1653 : {
1654 0 : if (adap->nr == -1) /* -1 means dynamically assign bus id */
1655 0 : return i2c_add_adapter(adap);
1656 :
1657 0 : return __i2c_add_numbered_adapter(adap);
1658 : }
1659 : EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
1660 :
1661 0 : static void i2c_do_del_adapter(struct i2c_driver *driver,
1662 : struct i2c_adapter *adapter)
1663 : {
1664 : struct i2c_client *client, *_n;
1665 :
1666 : /* Remove the devices we created ourselves as the result of hardware
1667 : * probing (using a driver's detect method) */
1668 0 : list_for_each_entry_safe(client, _n, &driver->clients, detected) {
1669 0 : if (client->adapter == adapter) {
1670 : dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",
1671 : client->name, client->addr);
1672 0 : list_del(&client->detected);
1673 0 : i2c_unregister_device(client);
1674 : }
1675 : }
1676 0 : }
1677 :
1678 0 : static int __unregister_client(struct device *dev, void *dummy)
1679 : {
1680 0 : struct i2c_client *client = i2c_verify_client(dev);
1681 0 : if (client && strcmp(client->name, "dummy"))
1682 0 : i2c_unregister_device(client);
1683 0 : return 0;
1684 : }
1685 :
1686 0 : static int __unregister_dummy(struct device *dev, void *dummy)
1687 : {
1688 0 : struct i2c_client *client = i2c_verify_client(dev);
1689 0 : i2c_unregister_device(client);
1690 0 : return 0;
1691 : }
1692 :
1693 0 : static int __process_removed_adapter(struct device_driver *d, void *data)
1694 : {
1695 0 : i2c_do_del_adapter(to_i2c_driver(d), data);
1696 0 : return 0;
1697 : }
1698 :
1699 : /**
1700 : * i2c_del_adapter - unregister I2C adapter
1701 : * @adap: the adapter being unregistered
1702 : * Context: can sleep
1703 : *
1704 : * This unregisters an I2C adapter which was previously registered
1705 : * by @i2c_add_adapter or @i2c_add_numbered_adapter.
1706 : */
1707 0 : void i2c_del_adapter(struct i2c_adapter *adap)
1708 : {
1709 : struct i2c_adapter *found;
1710 : struct i2c_client *client, *next;
1711 :
1712 : /* First make sure that this adapter was ever added */
1713 0 : mutex_lock(&core_lock);
1714 0 : found = idr_find(&i2c_adapter_idr, adap->nr);
1715 0 : mutex_unlock(&core_lock);
1716 0 : if (found != adap) {
1717 : pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name);
1718 : return;
1719 : }
1720 :
1721 0 : i2c_acpi_remove_space_handler(adap);
1722 : /* Tell drivers about this removal */
1723 0 : mutex_lock(&core_lock);
1724 0 : bus_for_each_drv(&i2c_bus_type, NULL, adap,
1725 : __process_removed_adapter);
1726 0 : mutex_unlock(&core_lock);
1727 :
1728 : /* Remove devices instantiated from sysfs */
1729 0 : mutex_lock_nested(&adap->userspace_clients_lock,
1730 : i2c_adapter_depth(adap));
1731 0 : list_for_each_entry_safe(client, next, &adap->userspace_clients,
1732 : detected) {
1733 : dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,
1734 : client->addr);
1735 0 : list_del(&client->detected);
1736 0 : i2c_unregister_device(client);
1737 : }
1738 0 : mutex_unlock(&adap->userspace_clients_lock);
1739 :
1740 : /* Detach any active clients. This can't fail, thus we do not
1741 : * check the returned value. This is a two-pass process, because
1742 : * we can't remove the dummy devices during the first pass: they
1743 : * could have been instantiated by real devices wishing to clean
1744 : * them up properly, so we give them a chance to do that first. */
1745 0 : device_for_each_child(&adap->dev, NULL, __unregister_client);
1746 0 : device_for_each_child(&adap->dev, NULL, __unregister_dummy);
1747 :
1748 : #ifdef CONFIG_I2C_COMPAT
1749 0 : class_compat_remove_link(i2c_adapter_compat_class, &adap->dev,
1750 : adap->dev.parent);
1751 : #endif
1752 :
1753 : /* device name is gone after device_unregister */
1754 : dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
1755 :
1756 0 : pm_runtime_disable(&adap->dev);
1757 :
1758 0 : i2c_host_notify_irq_teardown(adap);
1759 :
1760 : /* wait until all references to the device are gone
1761 : *
1762 : * FIXME: This is old code and should ideally be replaced by an
1763 : * alternative which results in decoupling the lifetime of the struct
1764 : * device from the i2c_adapter, like spi or netdev do. Any solution
1765 : * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled!
1766 : */
1767 0 : init_completion(&adap->dev_released);
1768 0 : device_unregister(&adap->dev);
1769 0 : wait_for_completion(&adap->dev_released);
1770 :
1771 : /* free bus id */
1772 0 : mutex_lock(&core_lock);
1773 0 : idr_remove(&i2c_adapter_idr, adap->nr);
1774 0 : mutex_unlock(&core_lock);
1775 :
1776 : /* Clear the device structure in case this adapter is ever going to be
1777 : added again */
1778 0 : memset(&adap->dev, 0, sizeof(adap->dev));
1779 : }
1780 : EXPORT_SYMBOL(i2c_del_adapter);
1781 :
1782 0 : static void devm_i2c_del_adapter(void *adapter)
1783 : {
1784 0 : i2c_del_adapter(adapter);
1785 0 : }
1786 :
1787 : /**
1788 : * devm_i2c_add_adapter - device-managed variant of i2c_add_adapter()
1789 : * @dev: managing device for adding this I2C adapter
1790 : * @adapter: the adapter to add
1791 : * Context: can sleep
1792 : *
1793 : * Add adapter with dynamic bus number, same with i2c_add_adapter()
1794 : * but the adapter will be auto deleted on driver detach.
1795 : */
1796 0 : int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter)
1797 : {
1798 : int ret;
1799 :
1800 0 : ret = i2c_add_adapter(adapter);
1801 0 : if (ret)
1802 : return ret;
1803 :
1804 : return devm_add_action_or_reset(dev, devm_i2c_del_adapter, adapter);
1805 : }
1806 : EXPORT_SYMBOL_GPL(devm_i2c_add_adapter);
1807 :
1808 0 : static int i2c_dev_or_parent_fwnode_match(struct device *dev, const void *data)
1809 : {
1810 0 : if (dev_fwnode(dev) == data)
1811 : return 1;
1812 :
1813 0 : if (dev->parent && dev_fwnode(dev->parent) == data)
1814 : return 1;
1815 :
1816 : return 0;
1817 : }
1818 :
1819 : /**
1820 : * i2c_find_adapter_by_fwnode() - find an i2c_adapter for the fwnode
1821 : * @fwnode: &struct fwnode_handle corresponding to the &struct i2c_adapter
1822 : *
1823 : * Look up and return the &struct i2c_adapter corresponding to the @fwnode.
1824 : * If no adapter can be found, or @fwnode is NULL, this returns NULL.
1825 : *
1826 : * The user must call put_device(&adapter->dev) once done with the i2c adapter.
1827 : */
1828 0 : struct i2c_adapter *i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode)
1829 : {
1830 : struct i2c_adapter *adapter;
1831 : struct device *dev;
1832 :
1833 0 : if (!fwnode)
1834 : return NULL;
1835 :
1836 0 : dev = bus_find_device(&i2c_bus_type, NULL, fwnode,
1837 : i2c_dev_or_parent_fwnode_match);
1838 0 : if (!dev)
1839 : return NULL;
1840 :
1841 0 : adapter = i2c_verify_adapter(dev);
1842 0 : if (!adapter)
1843 0 : put_device(dev);
1844 :
1845 : return adapter;
1846 : }
1847 : EXPORT_SYMBOL(i2c_find_adapter_by_fwnode);
1848 :
1849 : /**
1850 : * i2c_get_adapter_by_fwnode() - find an i2c_adapter for the fwnode
1851 : * @fwnode: &struct fwnode_handle corresponding to the &struct i2c_adapter
1852 : *
1853 : * Look up and return the &struct i2c_adapter corresponding to the @fwnode,
1854 : * and increment the adapter module's use count. If no adapter can be found,
1855 : * or @fwnode is NULL, this returns NULL.
1856 : *
1857 : * The user must call i2c_put_adapter(adapter) once done with the i2c adapter.
1858 : * Note that this is different from i2c_find_adapter_by_node().
1859 : */
1860 0 : struct i2c_adapter *i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode)
1861 : {
1862 : struct i2c_adapter *adapter;
1863 :
1864 0 : adapter = i2c_find_adapter_by_fwnode(fwnode);
1865 0 : if (!adapter)
1866 : return NULL;
1867 :
1868 0 : if (!try_module_get(adapter->owner)) {
1869 : put_device(&adapter->dev);
1870 : adapter = NULL;
1871 : }
1872 :
1873 0 : return adapter;
1874 : }
1875 : EXPORT_SYMBOL(i2c_get_adapter_by_fwnode);
1876 :
1877 : static void i2c_parse_timing(struct device *dev, char *prop_name, u32 *cur_val_p,
1878 : u32 def_val, bool use_def)
1879 : {
1880 : int ret;
1881 :
1882 0 : ret = device_property_read_u32(dev, prop_name, cur_val_p);
1883 0 : if (ret && use_def)
1884 0 : *cur_val_p = def_val;
1885 :
1886 : dev_dbg(dev, "%s: %u\n", prop_name, *cur_val_p);
1887 : }
1888 :
1889 : /**
1890 : * i2c_parse_fw_timings - get I2C related timing parameters from firmware
1891 : * @dev: The device to scan for I2C timing properties
1892 : * @t: the i2c_timings struct to be filled with values
1893 : * @use_defaults: bool to use sane defaults derived from the I2C specification
1894 : * when properties are not found, otherwise don't update
1895 : *
1896 : * Scan the device for the generic I2C properties describing timing parameters
1897 : * for the signal and fill the given struct with the results. If a property was
1898 : * not found and use_defaults was true, then maximum timings are assumed which
1899 : * are derived from the I2C specification. If use_defaults is not used, the
1900 : * results will be as before, so drivers can apply their own defaults before
1901 : * calling this helper. The latter is mainly intended for avoiding regressions
1902 : * of existing drivers which want to switch to this function. New drivers
1903 : * almost always should use the defaults.
1904 : */
1905 0 : void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults)
1906 : {
1907 0 : bool u = use_defaults;
1908 : u32 d;
1909 :
1910 0 : i2c_parse_timing(dev, "clock-frequency", &t->bus_freq_hz,
1911 : I2C_MAX_STANDARD_MODE_FREQ, u);
1912 :
1913 0 : d = t->bus_freq_hz <= I2C_MAX_STANDARD_MODE_FREQ ? 1000 :
1914 : t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120;
1915 0 : i2c_parse_timing(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns, d, u);
1916 :
1917 0 : d = t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120;
1918 0 : i2c_parse_timing(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns, d, u);
1919 :
1920 0 : i2c_parse_timing(dev, "i2c-scl-internal-delay-ns",
1921 : &t->scl_int_delay_ns, 0, u);
1922 0 : i2c_parse_timing(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns,
1923 : t->scl_fall_ns, u);
1924 0 : i2c_parse_timing(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns, 0, u);
1925 0 : i2c_parse_timing(dev, "i2c-digital-filter-width-ns",
1926 : &t->digital_filter_width_ns, 0, u);
1927 0 : i2c_parse_timing(dev, "i2c-analog-filter-cutoff-frequency",
1928 : &t->analog_filter_cutoff_freq_hz, 0, u);
1929 0 : }
1930 : EXPORT_SYMBOL_GPL(i2c_parse_fw_timings);
1931 :
1932 : /* ------------------------------------------------------------------------- */
1933 :
1934 1 : int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data))
1935 : {
1936 : int res;
1937 :
1938 1 : mutex_lock(&core_lock);
1939 1 : res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn);
1940 1 : mutex_unlock(&core_lock);
1941 :
1942 1 : return res;
1943 : }
1944 : EXPORT_SYMBOL_GPL(i2c_for_each_dev);
1945 :
1946 0 : static int __process_new_driver(struct device *dev, void *data)
1947 : {
1948 0 : if (dev->type != &i2c_adapter_type)
1949 : return 0;
1950 0 : return i2c_do_add_adapter(data, to_i2c_adapter(dev));
1951 : }
1952 :
1953 : /*
1954 : * An i2c_driver is used with one or more i2c_client (device) nodes to access
1955 : * i2c slave chips, on a bus instance associated with some i2c_adapter.
1956 : */
1957 :
1958 1 : int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
1959 : {
1960 : int res;
1961 :
1962 : /* Can't register until after driver model init */
1963 1 : if (WARN_ON(!is_registered))
1964 : return -EAGAIN;
1965 :
1966 : /* add the driver to the list of i2c drivers in the driver core */
1967 1 : driver->driver.owner = owner;
1968 1 : driver->driver.bus = &i2c_bus_type;
1969 2 : INIT_LIST_HEAD(&driver->clients);
1970 :
1971 : /* When registration returns, the driver core
1972 : * will have called probe() for all matching-but-unbound devices.
1973 : */
1974 1 : res = driver_register(&driver->driver);
1975 1 : if (res)
1976 : return res;
1977 :
1978 : pr_debug("driver [%s] registered\n", driver->driver.name);
1979 :
1980 : /* Walk the adapters that are already present */
1981 1 : i2c_for_each_dev(driver, __process_new_driver);
1982 :
1983 1 : return 0;
1984 : }
1985 : EXPORT_SYMBOL(i2c_register_driver);
1986 :
1987 0 : static int __process_removed_driver(struct device *dev, void *data)
1988 : {
1989 0 : if (dev->type == &i2c_adapter_type)
1990 0 : i2c_do_del_adapter(data, to_i2c_adapter(dev));
1991 0 : return 0;
1992 : }
1993 :
1994 : /**
1995 : * i2c_del_driver - unregister I2C driver
1996 : * @driver: the driver being unregistered
1997 : * Context: can sleep
1998 : */
1999 0 : void i2c_del_driver(struct i2c_driver *driver)
2000 : {
2001 0 : i2c_for_each_dev(driver, __process_removed_driver);
2002 :
2003 0 : driver_unregister(&driver->driver);
2004 : pr_debug("driver [%s] unregistered\n", driver->driver.name);
2005 0 : }
2006 : EXPORT_SYMBOL(i2c_del_driver);
2007 :
2008 : /* ------------------------------------------------------------------------- */
2009 :
2010 : struct i2c_cmd_arg {
2011 : unsigned cmd;
2012 : void *arg;
2013 : };
2014 :
2015 0 : static int i2c_cmd(struct device *dev, void *_arg)
2016 : {
2017 0 : struct i2c_client *client = i2c_verify_client(dev);
2018 0 : struct i2c_cmd_arg *arg = _arg;
2019 : struct i2c_driver *driver;
2020 :
2021 0 : if (!client || !client->dev.driver)
2022 : return 0;
2023 :
2024 0 : driver = to_i2c_driver(client->dev.driver);
2025 0 : if (driver->command)
2026 0 : driver->command(client, arg->cmd, arg->arg);
2027 : return 0;
2028 : }
2029 :
2030 0 : void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
2031 : {
2032 : struct i2c_cmd_arg cmd_arg;
2033 :
2034 0 : cmd_arg.cmd = cmd;
2035 0 : cmd_arg.arg = arg;
2036 0 : device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);
2037 0 : }
2038 : EXPORT_SYMBOL(i2c_clients_command);
2039 :
2040 1 : static int __init i2c_init(void)
2041 : {
2042 : int retval;
2043 :
2044 1 : retval = of_alias_get_highest_id("i2c");
2045 :
2046 1 : down_write(&__i2c_board_lock);
2047 1 : if (retval >= __i2c_first_dynamic_bus_num)
2048 0 : __i2c_first_dynamic_bus_num = retval + 1;
2049 1 : up_write(&__i2c_board_lock);
2050 :
2051 1 : retval = bus_register(&i2c_bus_type);
2052 1 : if (retval)
2053 : return retval;
2054 :
2055 1 : is_registered = true;
2056 :
2057 : #ifdef CONFIG_I2C_COMPAT
2058 1 : i2c_adapter_compat_class = class_compat_register("i2c-adapter");
2059 1 : if (!i2c_adapter_compat_class) {
2060 : retval = -ENOMEM;
2061 : goto bus_err;
2062 : }
2063 : #endif
2064 1 : retval = i2c_add_driver(&dummy_driver);
2065 1 : if (retval)
2066 : goto class_err;
2067 :
2068 : if (IS_ENABLED(CONFIG_OF_DYNAMIC))
2069 : WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier));
2070 : if (IS_ENABLED(CONFIG_ACPI))
2071 : WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier));
2072 :
2073 : return 0;
2074 :
2075 : class_err:
2076 : #ifdef CONFIG_I2C_COMPAT
2077 0 : class_compat_unregister(i2c_adapter_compat_class);
2078 : bus_err:
2079 : #endif
2080 0 : is_registered = false;
2081 0 : bus_unregister(&i2c_bus_type);
2082 0 : return retval;
2083 : }
2084 :
2085 0 : static void __exit i2c_exit(void)
2086 : {
2087 : if (IS_ENABLED(CONFIG_ACPI))
2088 : WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier));
2089 : if (IS_ENABLED(CONFIG_OF_DYNAMIC))
2090 : WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier));
2091 0 : i2c_del_driver(&dummy_driver);
2092 : #ifdef CONFIG_I2C_COMPAT
2093 0 : class_compat_unregister(i2c_adapter_compat_class);
2094 : #endif
2095 0 : bus_unregister(&i2c_bus_type);
2096 : tracepoint_synchronize_unregister();
2097 0 : }
2098 :
2099 : /* We must initialize early, because some subsystems register i2c drivers
2100 : * in subsys_initcall() code, but are linked (and initialized) before i2c.
2101 : */
2102 : postcore_initcall(i2c_init);
2103 : module_exit(i2c_exit);
2104 :
2105 : /* ----------------------------------------------------
2106 : * the functional interface to the i2c busses.
2107 : * ----------------------------------------------------
2108 : */
2109 :
2110 : /* Check if val is exceeding the quirk IFF quirk is non 0 */
2111 : #define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk)))
2112 :
2113 0 : static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg)
2114 : {
2115 0 : dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n",
2116 : err_msg, msg->addr, msg->len,
2117 : msg->flags & I2C_M_RD ? "read" : "write");
2118 0 : return -EOPNOTSUPP;
2119 : }
2120 :
2121 0 : static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
2122 : {
2123 0 : const struct i2c_adapter_quirks *q = adap->quirks;
2124 0 : int max_num = q->max_num_msgs, i;
2125 0 : bool do_len_check = true;
2126 :
2127 0 : if (q->flags & I2C_AQ_COMB) {
2128 0 : max_num = 2;
2129 :
2130 : /* special checks for combined messages */
2131 0 : if (num == 2) {
2132 0 : if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD)
2133 0 : return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write");
2134 :
2135 0 : if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD))
2136 0 : return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read");
2137 :
2138 0 : if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr)
2139 0 : return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr");
2140 :
2141 0 : if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len))
2142 0 : return i2c_quirk_error(adap, &msgs[0], "msg too long");
2143 :
2144 0 : if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len))
2145 0 : return i2c_quirk_error(adap, &msgs[1], "msg too long");
2146 :
2147 : do_len_check = false;
2148 : }
2149 : }
2150 :
2151 0 : if (i2c_quirk_exceeded(num, max_num))
2152 0 : return i2c_quirk_error(adap, &msgs[0], "too many messages");
2153 :
2154 0 : for (i = 0; i < num; i++) {
2155 0 : u16 len = msgs[i].len;
2156 :
2157 0 : if (msgs[i].flags & I2C_M_RD) {
2158 0 : if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len))
2159 0 : return i2c_quirk_error(adap, &msgs[i], "msg too long");
2160 :
2161 0 : if (q->flags & I2C_AQ_NO_ZERO_LEN_READ && len == 0)
2162 0 : return i2c_quirk_error(adap, &msgs[i], "no zero length");
2163 : } else {
2164 0 : if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len))
2165 0 : return i2c_quirk_error(adap, &msgs[i], "msg too long");
2166 :
2167 0 : if (q->flags & I2C_AQ_NO_ZERO_LEN_WRITE && len == 0)
2168 0 : return i2c_quirk_error(adap, &msgs[i], "no zero length");
2169 : }
2170 : }
2171 :
2172 : return 0;
2173 : }
2174 :
2175 : /**
2176 : * __i2c_transfer - unlocked flavor of i2c_transfer
2177 : * @adap: Handle to I2C bus
2178 : * @msgs: One or more messages to execute before STOP is issued to
2179 : * terminate the operation; each message begins with a START.
2180 : * @num: Number of messages to be executed.
2181 : *
2182 : * Returns negative errno, else the number of messages executed.
2183 : *
2184 : * Adapter lock must be held when calling this function. No debug logging
2185 : * takes place. adap->algo->master_xfer existence isn't checked.
2186 : */
2187 0 : int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
2188 : {
2189 : unsigned long orig_jiffies;
2190 : int ret, try;
2191 :
2192 0 : if (WARN_ON(!msgs || num < 1))
2193 : return -EINVAL;
2194 :
2195 0 : ret = __i2c_check_suspended(adap);
2196 0 : if (ret)
2197 : return ret;
2198 :
2199 0 : if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))
2200 : return -EOPNOTSUPP;
2201 :
2202 : /*
2203 : * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets
2204 : * enabled. This is an efficient way of keeping the for-loop from
2205 : * being executed when not needed.
2206 : */
2207 0 : if (static_branch_unlikely(&i2c_trace_msg_key)) {
2208 : int i;
2209 : for (i = 0; i < num; i++)
2210 : if (msgs[i].flags & I2C_M_RD)
2211 : trace_i2c_read(adap, &msgs[i], i);
2212 : else
2213 : trace_i2c_write(adap, &msgs[i], i);
2214 : }
2215 :
2216 : /* Retry automatically on arbitration loss */
2217 0 : orig_jiffies = jiffies;
2218 0 : for (ret = 0, try = 0; try <= adap->retries; try++) {
2219 0 : if (i2c_in_atomic_xfer_mode() && adap->algo->master_xfer_atomic)
2220 0 : ret = adap->algo->master_xfer_atomic(adap, msgs, num);
2221 : else
2222 0 : ret = adap->algo->master_xfer(adap, msgs, num);
2223 :
2224 0 : if (ret != -EAGAIN)
2225 : break;
2226 0 : if (time_after(jiffies, orig_jiffies + adap->timeout))
2227 : break;
2228 : }
2229 :
2230 0 : if (static_branch_unlikely(&i2c_trace_msg_key)) {
2231 : int i;
2232 : for (i = 0; i < ret; i++)
2233 : if (msgs[i].flags & I2C_M_RD)
2234 : trace_i2c_reply(adap, &msgs[i], i);
2235 : trace_i2c_result(adap, num, ret);
2236 : }
2237 :
2238 : return ret;
2239 : }
2240 : EXPORT_SYMBOL(__i2c_transfer);
2241 :
2242 : /**
2243 : * i2c_transfer - execute a single or combined I2C message
2244 : * @adap: Handle to I2C bus
2245 : * @msgs: One or more messages to execute before STOP is issued to
2246 : * terminate the operation; each message begins with a START.
2247 : * @num: Number of messages to be executed.
2248 : *
2249 : * Returns negative errno, else the number of messages executed.
2250 : *
2251 : * Note that there is no requirement that each message be sent to
2252 : * the same slave address, although that is the most common model.
2253 : */
2254 0 : int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
2255 : {
2256 : int ret;
2257 :
2258 0 : if (!adap->algo->master_xfer) {
2259 : dev_dbg(&adap->dev, "I2C level transfers not supported\n");
2260 : return -EOPNOTSUPP;
2261 : }
2262 :
2263 : /* REVISIT the fault reporting model here is weak:
2264 : *
2265 : * - When we get an error after receiving N bytes from a slave,
2266 : * there is no way to report "N".
2267 : *
2268 : * - When we get a NAK after transmitting N bytes to a slave,
2269 : * there is no way to report "N" ... or to let the master
2270 : * continue executing the rest of this combined message, if
2271 : * that's the appropriate response.
2272 : *
2273 : * - When for example "num" is two and we successfully complete
2274 : * the first message but get an error part way through the
2275 : * second, it's unclear whether that should be reported as
2276 : * one (discarding status on the second message) or errno
2277 : * (discarding status on the first one).
2278 : */
2279 0 : ret = __i2c_lock_bus_helper(adap);
2280 0 : if (ret)
2281 : return ret;
2282 :
2283 0 : ret = __i2c_transfer(adap, msgs, num);
2284 0 : i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
2285 :
2286 0 : return ret;
2287 : }
2288 : EXPORT_SYMBOL(i2c_transfer);
2289 :
2290 : /**
2291 : * i2c_transfer_buffer_flags - issue a single I2C message transferring data
2292 : * to/from a buffer
2293 : * @client: Handle to slave device
2294 : * @buf: Where the data is stored
2295 : * @count: How many bytes to transfer, must be less than 64k since msg.len is u16
2296 : * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads
2297 : *
2298 : * Returns negative errno, or else the number of bytes transferred.
2299 : */
2300 0 : int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf,
2301 : int count, u16 flags)
2302 : {
2303 : int ret;
2304 0 : struct i2c_msg msg = {
2305 0 : .addr = client->addr,
2306 0 : .flags = flags | (client->flags & I2C_M_TEN),
2307 : .len = count,
2308 : .buf = buf,
2309 : };
2310 :
2311 0 : ret = i2c_transfer(client->adapter, &msg, 1);
2312 :
2313 : /*
2314 : * If everything went ok (i.e. 1 msg transferred), return #bytes
2315 : * transferred, else error code.
2316 : */
2317 0 : return (ret == 1) ? count : ret;
2318 : }
2319 : EXPORT_SYMBOL(i2c_transfer_buffer_flags);
2320 :
2321 : /**
2322 : * i2c_get_device_id - get manufacturer, part id and die revision of a device
2323 : * @client: The device to query
2324 : * @id: The queried information
2325 : *
2326 : * Returns negative errno on error, zero on success.
2327 : */
2328 0 : int i2c_get_device_id(const struct i2c_client *client,
2329 : struct i2c_device_identity *id)
2330 : {
2331 0 : struct i2c_adapter *adap = client->adapter;
2332 : union i2c_smbus_data raw_id;
2333 : int ret;
2334 :
2335 0 : if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
2336 : return -EOPNOTSUPP;
2337 :
2338 0 : raw_id.block[0] = 3;
2339 0 : ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0,
2340 0 : I2C_SMBUS_READ, client->addr << 1,
2341 : I2C_SMBUS_I2C_BLOCK_DATA, &raw_id);
2342 0 : if (ret)
2343 : return ret;
2344 :
2345 0 : id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4);
2346 0 : id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3);
2347 0 : id->die_revision = raw_id.block[3] & 0x7;
2348 0 : return 0;
2349 : }
2350 : EXPORT_SYMBOL_GPL(i2c_get_device_id);
2351 :
2352 : /**
2353 : * i2c_client_get_device_id - get the driver match table entry of a device
2354 : * @client: the device to query. The device must be bound to a driver
2355 : *
2356 : * Returns a pointer to the matching entry if found, NULL otherwise.
2357 : */
2358 0 : const struct i2c_device_id *i2c_client_get_device_id(const struct i2c_client *client)
2359 : {
2360 0 : const struct i2c_driver *drv = to_i2c_driver(client->dev.driver);
2361 :
2362 0 : return i2c_match_id(drv->id_table, client);
2363 : }
2364 : EXPORT_SYMBOL_GPL(i2c_client_get_device_id);
2365 :
2366 : /* ----------------------------------------------------
2367 : * the i2c address scanning function
2368 : * Will not work for 10-bit addresses!
2369 : * ----------------------------------------------------
2370 : */
2371 :
2372 : /*
2373 : * Legacy default probe function, mostly relevant for SMBus. The default
2374 : * probe method is a quick write, but it is known to corrupt the 24RF08
2375 : * EEPROMs due to a state machine bug, and could also irreversibly
2376 : * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f,
2377 : * we use a short byte read instead. Also, some bus drivers don't implement
2378 : * quick write, so we fallback to a byte read in that case too.
2379 : * On x86, there is another special case for FSC hardware monitoring chips,
2380 : * which want regular byte reads (address 0x73.) Fortunately, these are the
2381 : * only known chips using this I2C address on PC hardware.
2382 : * Returns 1 if probe succeeded, 0 if not.
2383 : */
2384 0 : static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr)
2385 : {
2386 : int err;
2387 : union i2c_smbus_data dummy;
2388 :
2389 : #ifdef CONFIG_X86
2390 : if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON)
2391 : && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA))
2392 : err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
2393 : I2C_SMBUS_BYTE_DATA, &dummy);
2394 : else
2395 : #endif
2396 0 : if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50)
2397 0 : && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK))
2398 0 : err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0,
2399 : I2C_SMBUS_QUICK, NULL);
2400 0 : else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE))
2401 0 : err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
2402 : I2C_SMBUS_BYTE, &dummy);
2403 : else {
2404 0 : dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n",
2405 : addr);
2406 0 : err = -EOPNOTSUPP;
2407 : }
2408 :
2409 0 : return err >= 0;
2410 : }
2411 :
2412 0 : static int i2c_detect_address(struct i2c_client *temp_client,
2413 : struct i2c_driver *driver)
2414 : {
2415 : struct i2c_board_info info;
2416 0 : struct i2c_adapter *adapter = temp_client->adapter;
2417 0 : int addr = temp_client->addr;
2418 : int err;
2419 :
2420 : /* Make sure the address is valid */
2421 0 : err = i2c_check_7bit_addr_validity_strict(addr);
2422 0 : if (err) {
2423 0 : dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
2424 : addr);
2425 0 : return err;
2426 : }
2427 :
2428 : /* Skip if already in use (7 bit, no need to encode flags) */
2429 0 : if (i2c_check_addr_busy(adapter, addr))
2430 : return 0;
2431 :
2432 : /* Make sure there is something at this address */
2433 0 : if (!i2c_default_probe(adapter, addr))
2434 : return 0;
2435 :
2436 : /* Finally call the custom detection function */
2437 0 : memset(&info, 0, sizeof(struct i2c_board_info));
2438 0 : info.addr = addr;
2439 0 : err = driver->detect(temp_client, &info);
2440 0 : if (err) {
2441 : /* -ENODEV is returned if the detection fails. We catch it
2442 : here as this isn't an error. */
2443 0 : return err == -ENODEV ? 0 : err;
2444 : }
2445 :
2446 : /* Consistency check */
2447 0 : if (info.type[0] == '\0') {
2448 0 : dev_err(&adapter->dev,
2449 : "%s detection function provided no name for 0x%x\n",
2450 : driver->driver.name, addr);
2451 : } else {
2452 : struct i2c_client *client;
2453 :
2454 : /* Detection succeeded, instantiate the device */
2455 0 : if (adapter->class & I2C_CLASS_DEPRECATED)
2456 0 : dev_warn(&adapter->dev,
2457 : "This adapter will soon drop class based instantiation of devices. "
2458 : "Please make sure client 0x%02x gets instantiated by other means. "
2459 : "Check 'Documentation/i2c/instantiating-devices.rst' for details.\n",
2460 : info.addr);
2461 :
2462 : dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
2463 : info.type, info.addr);
2464 0 : client = i2c_new_client_device(adapter, &info);
2465 0 : if (!IS_ERR(client))
2466 0 : list_add_tail(&client->detected, &driver->clients);
2467 : else
2468 0 : dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n",
2469 : info.type, info.addr);
2470 : }
2471 : return 0;
2472 : }
2473 :
2474 0 : static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
2475 : {
2476 : const unsigned short *address_list;
2477 : struct i2c_client *temp_client;
2478 0 : int i, err = 0;
2479 :
2480 0 : address_list = driver->address_list;
2481 0 : if (!driver->detect || !address_list)
2482 : return 0;
2483 :
2484 : /* Warn that the adapter lost class based instantiation */
2485 0 : if (adapter->class == I2C_CLASS_DEPRECATED) {
2486 : dev_dbg(&adapter->dev,
2487 : "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. "
2488 : "If you need it, check 'Documentation/i2c/instantiating-devices.rst' for alternatives.\n",
2489 : driver->driver.name);
2490 : return 0;
2491 : }
2492 :
2493 : /* Stop here if the classes do not match */
2494 0 : if (!(adapter->class & driver->class))
2495 : return 0;
2496 :
2497 : /* Set up a temporary client to help detect callback */
2498 0 : temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
2499 0 : if (!temp_client)
2500 : return -ENOMEM;
2501 0 : temp_client->adapter = adapter;
2502 :
2503 0 : for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {
2504 : dev_dbg(&adapter->dev,
2505 : "found normal entry for adapter %d, addr 0x%02x\n",
2506 : i2c_adapter_id(adapter), address_list[i]);
2507 0 : temp_client->addr = address_list[i];
2508 0 : err = i2c_detect_address(temp_client, driver);
2509 0 : if (unlikely(err))
2510 : break;
2511 : }
2512 :
2513 0 : kfree(temp_client);
2514 0 : return err;
2515 : }
2516 :
2517 0 : int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr)
2518 : {
2519 0 : return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
2520 0 : I2C_SMBUS_QUICK, NULL) >= 0;
2521 : }
2522 : EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read);
2523 :
2524 : struct i2c_client *
2525 0 : i2c_new_scanned_device(struct i2c_adapter *adap,
2526 : struct i2c_board_info *info,
2527 : unsigned short const *addr_list,
2528 : int (*probe)(struct i2c_adapter *adap, unsigned short addr))
2529 : {
2530 : int i;
2531 :
2532 0 : if (!probe)
2533 0 : probe = i2c_default_probe;
2534 :
2535 0 : for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
2536 : /* Check address validity */
2537 0 : if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) {
2538 0 : dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n",
2539 : addr_list[i]);
2540 0 : continue;
2541 : }
2542 :
2543 : /* Check address availability (7 bit, no need to encode flags) */
2544 0 : if (i2c_check_addr_busy(adap, addr_list[i])) {
2545 : dev_dbg(&adap->dev,
2546 : "Address 0x%02x already in use, not probing\n",
2547 : addr_list[i]);
2548 0 : continue;
2549 : }
2550 :
2551 : /* Test address responsiveness */
2552 0 : if (probe(adap, addr_list[i]))
2553 : break;
2554 : }
2555 :
2556 0 : if (addr_list[i] == I2C_CLIENT_END) {
2557 : dev_dbg(&adap->dev, "Probing failed, no device found\n");
2558 : return ERR_PTR(-ENODEV);
2559 : }
2560 :
2561 0 : info->addr = addr_list[i];
2562 0 : return i2c_new_client_device(adap, info);
2563 : }
2564 : EXPORT_SYMBOL_GPL(i2c_new_scanned_device);
2565 :
2566 0 : struct i2c_adapter *i2c_get_adapter(int nr)
2567 : {
2568 : struct i2c_adapter *adapter;
2569 :
2570 0 : mutex_lock(&core_lock);
2571 0 : adapter = idr_find(&i2c_adapter_idr, nr);
2572 0 : if (!adapter)
2573 : goto exit;
2574 :
2575 0 : if (try_module_get(adapter->owner))
2576 0 : get_device(&adapter->dev);
2577 : else
2578 : adapter = NULL;
2579 :
2580 : exit:
2581 0 : mutex_unlock(&core_lock);
2582 0 : return adapter;
2583 : }
2584 : EXPORT_SYMBOL(i2c_get_adapter);
2585 :
2586 0 : void i2c_put_adapter(struct i2c_adapter *adap)
2587 : {
2588 0 : if (!adap)
2589 : return;
2590 :
2591 0 : module_put(adap->owner);
2592 : /* Should be last, otherwise we risk use-after-free with 'adap' */
2593 0 : put_device(&adap->dev);
2594 : }
2595 : EXPORT_SYMBOL(i2c_put_adapter);
2596 :
2597 : /**
2598 : * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg
2599 : * @msg: the message to be checked
2600 : * @threshold: the minimum number of bytes for which using DMA makes sense.
2601 : * Should at least be 1.
2602 : *
2603 : * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO.
2604 : * Or a valid pointer to be used with DMA. After use, release it by
2605 : * calling i2c_put_dma_safe_msg_buf().
2606 : *
2607 : * This function must only be called from process context!
2608 : */
2609 0 : u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold)
2610 : {
2611 : /* also skip 0-length msgs for bogus thresholds of 0 */
2612 : if (!threshold)
2613 : pr_debug("DMA buffer for addr=0x%02x with length 0 is bogus\n",
2614 : msg->addr);
2615 0 : if (msg->len < threshold || msg->len == 0)
2616 : return NULL;
2617 :
2618 0 : if (msg->flags & I2C_M_DMA_SAFE)
2619 0 : return msg->buf;
2620 :
2621 : pr_debug("using bounce buffer for addr=0x%02x, len=%d\n",
2622 : msg->addr, msg->len);
2623 :
2624 0 : if (msg->flags & I2C_M_RD)
2625 0 : return kzalloc(msg->len, GFP_KERNEL);
2626 : else
2627 0 : return kmemdup(msg->buf, msg->len, GFP_KERNEL);
2628 : }
2629 : EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf);
2630 :
2631 : /**
2632 : * i2c_put_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg
2633 : * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL.
2634 : * @msg: the message which the buffer corresponds to
2635 : * @xferred: bool saying if the message was transferred
2636 : */
2637 0 : void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred)
2638 : {
2639 0 : if (!buf || buf == msg->buf)
2640 : return;
2641 :
2642 0 : if (xferred && msg->flags & I2C_M_RD)
2643 0 : memcpy(msg->buf, buf, msg->len);
2644 :
2645 0 : kfree(buf);
2646 : }
2647 : EXPORT_SYMBOL_GPL(i2c_put_dma_safe_msg_buf);
2648 :
2649 : MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
2650 : MODULE_DESCRIPTION("I2C-Bus main module");
2651 : MODULE_LICENSE("GPL");
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