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1 | /* i2c-core.c - a device driver for the iic-bus interface */ |
2 | /* ------------------------------------------------------------------------- */ |
3 | /* Copyright (C) 1995-99 Simon G. Vogl |
4 | |
5 | This program is free software; you can redistribute it and/or modify |
6 | it under the terms of the GNU General Public License as published by |
7 | the Free Software Foundation; either version 2 of the License, or |
8 | (at your option) any later version. |
9 | |
10 | This program is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
13 | GNU General Public License for more details. */ |
14 | /* ------------------------------------------------------------------------- */ |
15 | |
16 | /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>. |
17 | All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl> |
18 | SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and |
19 | Jean Delvare <jdelvare@suse.de> |
20 | Mux support by Rodolfo Giometti <giometti@enneenne.com> and |
21 | Michael Lawnick <michael.lawnick.ext@nsn.com> |
22 | OF support is copyright (c) 2008 Jochen Friedrich <jochen@scram.de> |
23 | (based on a previous patch from Jon Smirl <jonsmirl@gmail.com>) and |
24 | (c) 2013 Wolfram Sang <wsa@the-dreams.de> |
25 | I2C ACPI code Copyright (C) 2014 Intel Corp |
26 | Author: Lan Tianyu <tianyu.lan@intel.com> |
27 | */ |
28 | |
29 | #include <linux/module.h> |
30 | #include <linux/kernel.h> |
31 | #include <linux/delay.h> |
32 | #include <linux/errno.h> |
33 | #include <linux/gpio.h> |
34 | #include <linux/slab.h> |
35 | #include <linux/i2c.h> |
36 | #include <linux/init.h> |
37 | #include <linux/idr.h> |
38 | #include <linux/mutex.h> |
39 | #include <linux/of.h> |
40 | #include <linux/of_device.h> |
41 | #include <linux/of_irq.h> |
42 | #include <linux/clk/clk-conf.h> |
43 | #include <linux/completion.h> |
44 | #include <linux/hardirq.h> |
45 | #include <linux/irqflags.h> |
46 | #include <linux/rwsem.h> |
47 | #include <linux/pm_runtime.h> |
48 | #include <linux/pm_domain.h> |
49 | #include <linux/acpi.h> |
50 | #include <linux/jump_label.h> |
51 | #include <asm/uaccess.h> |
52 | |
53 | #include "i2c-core.h" |
54 | |
55 | #define CREATE_TRACE_POINTS |
56 | #include <trace/events/i2c.h> |
57 | |
58 | /* core_lock protects i2c_adapter_idr, and guarantees |
59 | that device detection, deletion of detected devices, and attach_adapter |
60 | calls are serialized */ |
61 | static DEFINE_MUTEX(core_lock); |
62 | static DEFINE_IDR(i2c_adapter_idr); |
63 | |
64 | static struct device_type i2c_client_type; |
65 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
66 | |
67 | static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE; |
68 | |
69 | void i2c_transfer_trace_reg(void) |
70 | { |
71 | static_key_slow_inc(&i2c_trace_msg); |
72 | } |
73 | |
74 | void i2c_transfer_trace_unreg(void) |
75 | { |
76 | static_key_slow_dec(&i2c_trace_msg); |
77 | } |
78 | |
79 | #if defined(CONFIG_ACPI) |
80 | struct acpi_i2c_handler_data { |
81 | struct acpi_connection_info info; |
82 | struct i2c_adapter *adapter; |
83 | }; |
84 | |
85 | struct gsb_buffer { |
86 | u8 status; |
87 | u8 len; |
88 | union { |
89 | u16 wdata; |
90 | u8 bdata; |
91 | u8 data[0]; |
92 | }; |
93 | } __packed; |
94 | |
95 | static int acpi_i2c_add_resource(struct acpi_resource *ares, void *data) |
96 | { |
97 | struct i2c_board_info *info = data; |
98 | |
99 | if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { |
100 | struct acpi_resource_i2c_serialbus *sb; |
101 | |
102 | sb = &ares->data.i2c_serial_bus; |
103 | if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_I2C) { |
104 | info->addr = sb->slave_address; |
105 | if (sb->access_mode == ACPI_I2C_10BIT_MODE) |
106 | info->flags |= I2C_CLIENT_TEN; |
107 | } |
108 | } else if (info->irq < 0) { |
109 | struct resource r; |
110 | |
111 | if (acpi_dev_resource_interrupt(ares, 0, &r)) |
112 | info->irq = r.start; |
113 | } |
114 | |
115 | /* Tell the ACPI core to skip this resource */ |
116 | return 1; |
117 | } |
118 | |
119 | static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level, |
120 | void *data, void **return_value) |
121 | { |
122 | struct i2c_adapter *adapter = data; |
123 | struct list_head resource_list; |
124 | struct i2c_board_info info; |
125 | struct acpi_device *adev; |
126 | int ret; |
127 | |
128 | if (acpi_bus_get_device(handle, &adev)) |
129 | return AE_OK; |
130 | if (acpi_bus_get_status(adev) || !adev->status.present) |
131 | return AE_OK; |
132 | |
133 | memset(&info, 0, sizeof(info)); |
134 | info.acpi_node.companion = adev; |
135 | info.irq = -1; |
136 | |
137 | INIT_LIST_HEAD(&resource_list); |
138 | ret = acpi_dev_get_resources(adev, &resource_list, |
139 | acpi_i2c_add_resource, &info); |
140 | acpi_dev_free_resource_list(&resource_list); |
141 | |
142 | if (ret < 0 || !info.addr) |
143 | return AE_OK; |
144 | |
145 | adev->power.flags.ignore_parent = true; |
146 | strlcpy(info.type, dev_name(&adev->dev), sizeof(info.type)); |
147 | if (!i2c_new_device(adapter, &info)) { |
148 | adev->power.flags.ignore_parent = false; |
149 | dev_err(&adapter->dev, |
150 | "failed to add I2C device %s from ACPI\n", |
151 | dev_name(&adev->dev)); |
152 | } |
153 | |
154 | return AE_OK; |
155 | } |
156 | |
157 | /** |
158 | * acpi_i2c_register_devices - enumerate I2C slave devices behind adapter |
159 | * @adap: pointer to adapter |
160 | * |
161 | * Enumerate all I2C slave devices behind this adapter by walking the ACPI |
162 | * namespace. When a device is found it will be added to the Linux device |
163 | * model and bound to the corresponding ACPI handle. |
164 | */ |
165 | static void acpi_i2c_register_devices(struct i2c_adapter *adap) |
166 | { |
167 | acpi_handle handle; |
168 | acpi_status status; |
169 | |
170 | if (!adap->dev.parent) |
171 | return; |
172 | |
173 | handle = ACPI_HANDLE(adap->dev.parent); |
174 | if (!handle) |
175 | return; |
176 | |
177 | status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, |
178 | acpi_i2c_add_device, NULL, |
179 | adap, NULL); |
180 | if (ACPI_FAILURE(status)) |
181 | dev_warn(&adap->dev, "failed to enumerate I2C slaves\n"); |
182 | } |
183 | |
184 | #else /* CONFIG_ACPI */ |
185 | static inline void acpi_i2c_register_devices(struct i2c_adapter *adap) { } |
186 | #endif /* CONFIG_ACPI */ |
187 | |
188 | #ifdef CONFIG_ACPI_I2C_OPREGION |
189 | static int acpi_gsb_i2c_read_bytes(struct i2c_client *client, |
190 | u8 cmd, u8 *data, u8 data_len) |
191 | { |
192 | |
193 | struct i2c_msg msgs[2]; |
194 | int ret; |
195 | u8 *buffer; |
196 | |
197 | buffer = kzalloc(data_len, GFP_KERNEL); |
198 | if (!buffer) |
199 | return AE_NO_MEMORY; |
200 | |
201 | msgs[0].addr = client->addr; |
202 | msgs[0].flags = client->flags; |
203 | msgs[0].len = 1; |
204 | msgs[0].buf = &cmd; |
205 | |
206 | msgs[1].addr = client->addr; |
207 | msgs[1].flags = client->flags | I2C_M_RD; |
208 | msgs[1].len = data_len; |
209 | msgs[1].buf = buffer; |
210 | |
211 | ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); |
212 | if (ret < 0) |
213 | dev_err(&client->adapter->dev, "i2c read failed\n"); |
214 | else |
215 | memcpy(data, buffer, data_len); |
216 | |
217 | kfree(buffer); |
218 | return ret; |
219 | } |
220 | |
221 | static int acpi_gsb_i2c_write_bytes(struct i2c_client *client, |
222 | u8 cmd, u8 *data, u8 data_len) |
223 | { |
224 | |
225 | struct i2c_msg msgs[1]; |
226 | u8 *buffer; |
227 | int ret = AE_OK; |
228 | |
229 | buffer = kzalloc(data_len + 1, GFP_KERNEL); |
230 | if (!buffer) |
231 | return AE_NO_MEMORY; |
232 | |
233 | buffer[0] = cmd; |
234 | memcpy(buffer + 1, data, data_len); |
235 | |
236 | msgs[0].addr = client->addr; |
237 | msgs[0].flags = client->flags; |
238 | msgs[0].len = data_len + 1; |
239 | msgs[0].buf = buffer; |
240 | |
241 | ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); |
242 | if (ret < 0) |
243 | dev_err(&client->adapter->dev, "i2c write failed\n"); |
244 | |
245 | kfree(buffer); |
246 | return ret; |
247 | } |
248 | |
249 | static acpi_status |
250 | acpi_i2c_space_handler(u32 function, acpi_physical_address command, |
251 | u32 bits, u64 *value64, |
252 | void *handler_context, void *region_context) |
253 | { |
254 | struct gsb_buffer *gsb = (struct gsb_buffer *)value64; |
255 | struct acpi_i2c_handler_data *data = handler_context; |
256 | struct acpi_connection_info *info = &data->info; |
257 | struct acpi_resource_i2c_serialbus *sb; |
258 | struct i2c_adapter *adapter = data->adapter; |
259 | struct i2c_client client; |
260 | struct acpi_resource *ares; |
261 | u32 accessor_type = function >> 16; |
262 | u8 action = function & ACPI_IO_MASK; |
263 | acpi_status ret = AE_OK; |
264 | int status; |
265 | |
266 | ret = acpi_buffer_to_resource(info->connection, info->length, &ares); |
267 | if (ACPI_FAILURE(ret)) |
268 | return ret; |
269 | |
270 | if (!value64 || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) { |
271 | ret = AE_BAD_PARAMETER; |
272 | goto err; |
273 | } |
274 | |
275 | sb = &ares->data.i2c_serial_bus; |
276 | if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) { |
277 | ret = AE_BAD_PARAMETER; |
278 | goto err; |
279 | } |
280 | |
281 | memset(&client, 0, sizeof(client)); |
282 | client.adapter = adapter; |
283 | client.addr = sb->slave_address; |
284 | client.flags = 0; |
285 | |
286 | if (sb->access_mode == ACPI_I2C_10BIT_MODE) |
287 | client.flags |= I2C_CLIENT_TEN; |
288 | |
289 | switch (accessor_type) { |
290 | case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV: |
291 | if (action == ACPI_READ) { |
292 | status = i2c_smbus_read_byte(&client); |
293 | if (status >= 0) { |
294 | gsb->bdata = status; |
295 | status = 0; |
296 | } |
297 | } else { |
298 | status = i2c_smbus_write_byte(&client, gsb->bdata); |
299 | } |
300 | break; |
301 | |
302 | case ACPI_GSB_ACCESS_ATTRIB_BYTE: |
303 | if (action == ACPI_READ) { |
304 | status = i2c_smbus_read_byte_data(&client, command); |
305 | if (status >= 0) { |
306 | gsb->bdata = status; |
307 | status = 0; |
308 | } |
309 | } else { |
310 | status = i2c_smbus_write_byte_data(&client, command, |
311 | gsb->bdata); |
312 | } |
313 | break; |
314 | |
315 | case ACPI_GSB_ACCESS_ATTRIB_WORD: |
316 | if (action == ACPI_READ) { |
317 | status = i2c_smbus_read_word_data(&client, command); |
318 | if (status >= 0) { |
319 | gsb->wdata = status; |
320 | status = 0; |
321 | } |
322 | } else { |
323 | status = i2c_smbus_write_word_data(&client, command, |
324 | gsb->wdata); |
325 | } |
326 | break; |
327 | |
328 | case ACPI_GSB_ACCESS_ATTRIB_BLOCK: |
329 | if (action == ACPI_READ) { |
330 | status = i2c_smbus_read_block_data(&client, command, |
331 | gsb->data); |
332 | if (status >= 0) { |
333 | gsb->len = status; |
334 | status = 0; |
335 | } |
336 | } else { |
337 | status = i2c_smbus_write_block_data(&client, command, |
338 | gsb->len, gsb->data); |
339 | } |
340 | break; |
341 | |
342 | case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE: |
343 | if (action == ACPI_READ) { |
344 | status = acpi_gsb_i2c_read_bytes(&client, command, |
345 | gsb->data, info->access_length); |
346 | if (status > 0) |
347 | status = 0; |
348 | } else { |
349 | status = acpi_gsb_i2c_write_bytes(&client, command, |
350 | gsb->data, info->access_length); |
351 | } |
352 | break; |
353 | |
354 | default: |
355 | pr_info("protocol(0x%02x) is not supported.\n", accessor_type); |
356 | ret = AE_BAD_PARAMETER; |
357 | goto err; |
358 | } |
359 | |
360 | gsb->status = status; |
361 | |
362 | err: |
363 | ACPI_FREE(ares); |
364 | return ret; |
365 | } |
366 | |
367 | |
368 | static int acpi_i2c_install_space_handler(struct i2c_adapter *adapter) |
369 | { |
370 | acpi_handle handle; |
371 | struct acpi_i2c_handler_data *data; |
372 | acpi_status status; |
373 | |
374 | if (!adapter->dev.parent) |
375 | return -ENODEV; |
376 | |
377 | handle = ACPI_HANDLE(adapter->dev.parent); |
378 | |
379 | if (!handle) |
380 | return -ENODEV; |
381 | |
382 | data = kzalloc(sizeof(struct acpi_i2c_handler_data), |
383 | GFP_KERNEL); |
384 | if (!data) |
385 | return -ENOMEM; |
386 | |
387 | data->adapter = adapter; |
388 | status = acpi_bus_attach_private_data(handle, (void *)data); |
389 | if (ACPI_FAILURE(status)) { |
390 | kfree(data); |
391 | return -ENOMEM; |
392 | } |
393 | |
394 | status = acpi_install_address_space_handler(handle, |
395 | ACPI_ADR_SPACE_GSBUS, |
396 | &acpi_i2c_space_handler, |
397 | NULL, |
398 | data); |
399 | if (ACPI_FAILURE(status)) { |
400 | dev_err(&adapter->dev, "Error installing i2c space handler\n"); |
401 | acpi_bus_detach_private_data(handle); |
402 | kfree(data); |
403 | return -ENOMEM; |
404 | } |
405 | |
406 | return 0; |
407 | } |
408 | |
409 | static void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter) |
410 | { |
411 | acpi_handle handle; |
412 | struct acpi_i2c_handler_data *data; |
413 | acpi_status status; |
414 | |
415 | if (!adapter->dev.parent) |
416 | return; |
417 | |
418 | handle = ACPI_HANDLE(adapter->dev.parent); |
419 | |
420 | if (!handle) |
421 | return; |
422 | |
423 | acpi_remove_address_space_handler(handle, |
424 | ACPI_ADR_SPACE_GSBUS, |
425 | &acpi_i2c_space_handler); |
426 | |
427 | status = acpi_bus_get_private_data(handle, (void **)&data); |
428 | if (ACPI_SUCCESS(status)) |
429 | kfree(data); |
430 | |
431 | acpi_bus_detach_private_data(handle); |
432 | } |
433 | #else /* CONFIG_ACPI_I2C_OPREGION */ |
434 | static inline void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter) |
435 | { } |
436 | |
437 | static inline int acpi_i2c_install_space_handler(struct i2c_adapter *adapter) |
438 | { return 0; } |
439 | #endif /* CONFIG_ACPI_I2C_OPREGION */ |
440 | |
441 | /* ------------------------------------------------------------------------- */ |
442 | |
443 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
444 | const struct i2c_client *client) |
445 | { |
446 | while (id->name[0]) { |
447 | if (strcmp(client->name, id->name) == 0) |
448 | return id; |
449 | id++; |
450 | } |
451 | return NULL; |
452 | } |
453 | |
454 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
455 | { |
456 | struct i2c_client *client = i2c_verify_client(dev); |
457 | struct i2c_driver *driver; |
458 | |
459 | if (!client) |
460 | return 0; |
461 | |
462 | /* Attempt an OF style match */ |
463 | if (of_driver_match_device(dev, drv)) |
464 | return 1; |
465 | |
466 | /* Then ACPI style match */ |
467 | if (acpi_driver_match_device(dev, drv)) |
468 | return 1; |
469 | |
470 | driver = to_i2c_driver(drv); |
471 | /* match on an id table if there is one */ |
472 | if (driver->id_table) |
473 | return i2c_match_id(driver->id_table, client) != NULL; |
474 | |
475 | return 0; |
476 | } |
477 | |
478 | |
479 | /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ |
480 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
481 | { |
482 | struct i2c_client *client = to_i2c_client(dev); |
483 | int rc; |
484 | |
485 | rc = acpi_device_uevent_modalias(dev, env); |
486 | if (rc != -ENODEV) |
487 | return rc; |
488 | |
489 | if (add_uevent_var(env, "MODALIAS=%s%s", |
490 | I2C_MODULE_PREFIX, client->name)) |
491 | return -ENOMEM; |
492 | dev_dbg(dev, "uevent\n"); |
493 | return 0; |
494 | } |
495 | |
496 | /* i2c bus recovery routines */ |
497 | static int get_scl_gpio_value(struct i2c_adapter *adap) |
498 | { |
499 | return gpio_get_value(adap->bus_recovery_info->scl_gpio); |
500 | } |
501 | |
502 | static void set_scl_gpio_value(struct i2c_adapter *adap, int val) |
503 | { |
504 | gpio_set_value(adap->bus_recovery_info->scl_gpio, val); |
505 | } |
506 | |
507 | static int get_sda_gpio_value(struct i2c_adapter *adap) |
508 | { |
509 | return gpio_get_value(adap->bus_recovery_info->sda_gpio); |
510 | } |
511 | |
512 | static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap) |
513 | { |
514 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; |
515 | struct device *dev = &adap->dev; |
516 | int ret = 0; |
517 | |
518 | ret = gpio_request_one(bri->scl_gpio, GPIOF_OPEN_DRAIN | |
519 | GPIOF_OUT_INIT_HIGH, "i2c-scl"); |
520 | if (ret) { |
521 | dev_warn(dev, "Can't get SCL gpio: %d\n", bri->scl_gpio); |
522 | return ret; |
523 | } |
524 | |
525 | if (bri->get_sda) { |
526 | if (gpio_request_one(bri->sda_gpio, GPIOF_IN, "i2c-sda")) { |
527 | /* work without SDA polling */ |
528 | dev_warn(dev, "Can't get SDA gpio: %d. Not using SDA polling\n", |
529 | bri->sda_gpio); |
530 | bri->get_sda = NULL; |
531 | } |
532 | } |
533 | |
534 | return ret; |
535 | } |
536 | |
537 | static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap) |
538 | { |
539 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; |
540 | |
541 | if (bri->get_sda) |
542 | gpio_free(bri->sda_gpio); |
543 | |
544 | gpio_free(bri->scl_gpio); |
545 | } |
546 | |
547 | /* |
548 | * We are generating clock pulses. ndelay() determines durating of clk pulses. |
549 | * We will generate clock with rate 100 KHz and so duration of both clock levels |
550 | * is: delay in ns = (10^6 / 100) / 2 |
551 | */ |
552 | #define RECOVERY_NDELAY 5000 |
553 | #define RECOVERY_CLK_CNT 9 |
554 | |
555 | static int i2c_generic_recovery(struct i2c_adapter *adap) |
556 | { |
557 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; |
558 | int i = 0, val = 1, ret = 0; |
559 | |
560 | if (bri->prepare_recovery) |
561 | bri->prepare_recovery(bri); |
562 | |
563 | /* |
564 | * By this time SCL is high, as we need to give 9 falling-rising edges |
565 | */ |
566 | while (i++ < RECOVERY_CLK_CNT * 2) { |
567 | if (val) { |
568 | /* Break if SDA is high */ |
569 | if (bri->get_sda && bri->get_sda(adap)) |
570 | break; |
571 | /* SCL shouldn't be low here */ |
572 | if (!bri->get_scl(adap)) { |
573 | dev_err(&adap->dev, |
574 | "SCL is stuck low, exit recovery\n"); |
575 | ret = -EBUSY; |
576 | break; |
577 | } |
578 | } |
579 | |
580 | val = !val; |
581 | bri->set_scl(adap, val); |
582 | ndelay(RECOVERY_NDELAY); |
583 | } |
584 | |
585 | if (bri->unprepare_recovery) |
586 | bri->unprepare_recovery(bri); |
587 | |
588 | return ret; |
589 | } |
590 | |
591 | int i2c_generic_scl_recovery(struct i2c_adapter *adap) |
592 | { |
593 | adap->bus_recovery_info->set_scl(adap, 1); |
594 | return i2c_generic_recovery(adap); |
595 | } |
596 | |
597 | int i2c_generic_gpio_recovery(struct i2c_adapter *adap) |
598 | { |
599 | int ret; |
600 | |
601 | ret = i2c_get_gpios_for_recovery(adap); |
602 | if (ret) |
603 | return ret; |
604 | |
605 | ret = i2c_generic_recovery(adap); |
606 | i2c_put_gpios_for_recovery(adap); |
607 | |
608 | return ret; |
609 | } |
610 | |
611 | int i2c_recover_bus(struct i2c_adapter *adap) |
612 | { |
613 | if (!adap->bus_recovery_info) |
614 | return -EOPNOTSUPP; |
615 | |
616 | dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); |
617 | return adap->bus_recovery_info->recover_bus(adap); |
618 | } |
619 | |
620 | static int i2c_device_probe(struct device *dev) |
621 | { |
622 | struct i2c_client *client = i2c_verify_client(dev); |
623 | struct i2c_driver *driver; |
624 | int status; |
625 | |
626 | if (!client) |
627 | return 0; |
628 | |
629 | driver = to_i2c_driver(dev->driver); |
630 | if (!driver->probe || !driver->id_table) |
631 | return -ENODEV; |
632 | |
633 | if (!device_can_wakeup(&client->dev)) |
634 | device_init_wakeup(&client->dev, |
635 | client->flags & I2C_CLIENT_WAKE); |
636 | dev_dbg(dev, "probe\n"); |
637 | |
638 | status = of_clk_set_defaults(dev->of_node, false); |
639 | if (status < 0) |
640 | return status; |
641 | |
642 | status = dev_pm_domain_attach(&client->dev, true); |
643 | if (status != -EPROBE_DEFER) { |
644 | status = driver->probe(client, i2c_match_id(driver->id_table, |
645 | client)); |
646 | if (status) |
647 | dev_pm_domain_detach(&client->dev, true); |
648 | } |
649 | |
650 | return status; |
651 | } |
652 | |
653 | static int i2c_device_remove(struct device *dev) |
654 | { |
655 | struct i2c_client *client = i2c_verify_client(dev); |
656 | struct i2c_driver *driver; |
657 | int status = 0; |
658 | |
659 | if (!client || !dev->driver) |
660 | return 0; |
661 | |
662 | driver = to_i2c_driver(dev->driver); |
663 | if (driver->remove) { |
664 | dev_dbg(dev, "remove\n"); |
665 | status = driver->remove(client); |
666 | } |
667 | |
668 | if (dev->of_node) |
669 | irq_dispose_mapping(client->irq); |
670 | |
671 | dev_pm_domain_detach(&client->dev, true); |
672 | return status; |
673 | } |
674 | |
675 | static void i2c_device_shutdown(struct device *dev) |
676 | { |
677 | struct i2c_client *client = i2c_verify_client(dev); |
678 | struct i2c_driver *driver; |
679 | |
680 | if (!client || !dev->driver) |
681 | return; |
682 | driver = to_i2c_driver(dev->driver); |
683 | if (driver->shutdown) |
684 | driver->shutdown(client); |
685 | } |
686 | |
687 | #ifdef CONFIG_PM_SLEEP |
688 | static int i2c_legacy_suspend(struct device *dev, pm_message_t mesg) |
689 | { |
690 | struct i2c_client *client = i2c_verify_client(dev); |
691 | struct i2c_driver *driver; |
692 | |
693 | if (!client || !dev->driver) |
694 | return 0; |
695 | driver = to_i2c_driver(dev->driver); |
696 | if (!driver->suspend) |
697 | return 0; |
698 | return driver->suspend(client, mesg); |
699 | } |
700 | |
701 | static int i2c_legacy_resume(struct device *dev) |
702 | { |
703 | struct i2c_client *client = i2c_verify_client(dev); |
704 | struct i2c_driver *driver; |
705 | |
706 | if (!client || !dev->driver) |
707 | return 0; |
708 | driver = to_i2c_driver(dev->driver); |
709 | if (!driver->resume) |
710 | return 0; |
711 | return driver->resume(client); |
712 | } |
713 | |
714 | static int i2c_device_pm_suspend(struct device *dev) |
715 | { |
716 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
717 | |
718 | if (pm) |
719 | return pm_generic_suspend(dev); |
720 | else |
721 | return i2c_legacy_suspend(dev, PMSG_SUSPEND); |
722 | } |
723 | |
724 | static int i2c_device_pm_resume(struct device *dev) |
725 | { |
726 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
727 | |
728 | if (pm) |
729 | return pm_generic_resume(dev); |
730 | else |
731 | return i2c_legacy_resume(dev); |
732 | } |
733 | |
734 | static int i2c_device_pm_freeze(struct device *dev) |
735 | { |
736 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
737 | |
738 | if (pm) |
739 | return pm_generic_freeze(dev); |
740 | else |
741 | return i2c_legacy_suspend(dev, PMSG_FREEZE); |
742 | } |
743 | |
744 | static int i2c_device_pm_thaw(struct device *dev) |
745 | { |
746 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
747 | |
748 | if (pm) |
749 | return pm_generic_thaw(dev); |
750 | else |
751 | return i2c_legacy_resume(dev); |
752 | } |
753 | |
754 | static int i2c_device_pm_poweroff(struct device *dev) |
755 | { |
756 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
757 | |
758 | if (pm) |
759 | return pm_generic_poweroff(dev); |
760 | else |
761 | return i2c_legacy_suspend(dev, PMSG_HIBERNATE); |
762 | } |
763 | |
764 | static int i2c_device_pm_restore(struct device *dev) |
765 | { |
766 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
767 | |
768 | if (pm) |
769 | return pm_generic_restore(dev); |
770 | else |
771 | return i2c_legacy_resume(dev); |
772 | } |
773 | #else /* !CONFIG_PM_SLEEP */ |
774 | #define i2c_device_pm_suspend NULL |
775 | #define i2c_device_pm_resume NULL |
776 | #define i2c_device_pm_freeze NULL |
777 | #define i2c_device_pm_thaw NULL |
778 | #define i2c_device_pm_poweroff NULL |
779 | #define i2c_device_pm_restore NULL |
780 | #endif /* !CONFIG_PM_SLEEP */ |
781 | |
782 | static void i2c_client_dev_release(struct device *dev) |
783 | { |
784 | kfree(to_i2c_client(dev)); |
785 | } |
786 | |
787 | static ssize_t |
788 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
789 | { |
790 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
791 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); |
792 | } |
793 | |
794 | static ssize_t |
795 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) |
796 | { |
797 | struct i2c_client *client = to_i2c_client(dev); |
798 | int len; |
799 | |
800 | len = acpi_device_modalias(dev, buf, PAGE_SIZE -1); |
801 | if (len != -ENODEV) |
802 | return len; |
803 | |
804 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
805 | } |
806 | |
807 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
808 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
809 | |
810 | static struct attribute *i2c_dev_attrs[] = { |
811 | &dev_attr_name.attr, |
812 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
813 | &dev_attr_modalias.attr, |
814 | NULL |
815 | }; |
816 | |
817 | static struct attribute_group i2c_dev_attr_group = { |
818 | .attrs = i2c_dev_attrs, |
819 | }; |
820 | |
821 | static const struct attribute_group *i2c_dev_attr_groups[] = { |
822 | &i2c_dev_attr_group, |
823 | NULL |
824 | }; |
825 | |
826 | static const struct dev_pm_ops i2c_device_pm_ops = { |
827 | .suspend = i2c_device_pm_suspend, |
828 | .resume = i2c_device_pm_resume, |
829 | .freeze = i2c_device_pm_freeze, |
830 | .thaw = i2c_device_pm_thaw, |
831 | .poweroff = i2c_device_pm_poweroff, |
832 | .restore = i2c_device_pm_restore, |
833 | SET_RUNTIME_PM_OPS( |
834 | pm_generic_runtime_suspend, |
835 | pm_generic_runtime_resume, |
836 | NULL |
837 | ) |
838 | }; |
839 | |
840 | struct bus_type i2c_bus_type = { |
841 | .name = "i2c", |
842 | .match = i2c_device_match, |
843 | .probe = i2c_device_probe, |
844 | .remove = i2c_device_remove, |
845 | .shutdown = i2c_device_shutdown, |
846 | .pm = &i2c_device_pm_ops, |
847 | }; |
848 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
849 | |
850 | static struct device_type i2c_client_type = { |
851 | .groups = i2c_dev_attr_groups, |
852 | .uevent = i2c_device_uevent, |
853 | .release = i2c_client_dev_release, |
854 | }; |
855 | |
856 | |
857 | /** |
858 | * i2c_verify_client - return parameter as i2c_client, or NULL |
859 | * @dev: device, probably from some driver model iterator |
860 | * |
861 | * When traversing the driver model tree, perhaps using driver model |
862 | * iterators like @device_for_each_child(), you can't assume very much |
863 | * about the nodes you find. Use this function to avoid oopses caused |
864 | * by wrongly treating some non-I2C device as an i2c_client. |
865 | */ |
866 | struct i2c_client *i2c_verify_client(struct device *dev) |
867 | { |
868 | return (dev->type == &i2c_client_type) |
869 | ? to_i2c_client(dev) |
870 | : NULL; |
871 | } |
872 | EXPORT_SYMBOL(i2c_verify_client); |
873 | |
874 | |
875 | /* This is a permissive address validity check, I2C address map constraints |
876 | * are purposely not enforced, except for the general call address. */ |
877 | static int i2c_check_client_addr_validity(const struct i2c_client *client) |
878 | { |
879 | if (client->flags & I2C_CLIENT_TEN) { |
880 | /* 10-bit address, all values are valid */ |
881 | if (client->addr > 0x3ff) |
882 | return -EINVAL; |
883 | } else { |
884 | /* 7-bit address, reject the general call address */ |
885 | if (client->addr == 0x00 || client->addr > 0x7f) |
886 | return -EINVAL; |
887 | } |
888 | return 0; |
889 | } |
890 | |
891 | /* And this is a strict address validity check, used when probing. If a |
892 | * device uses a reserved address, then it shouldn't be probed. 7-bit |
893 | * addressing is assumed, 10-bit address devices are rare and should be |
894 | * explicitly enumerated. */ |
895 | static int i2c_check_addr_validity(unsigned short addr) |
896 | { |
897 | /* |
898 | * Reserved addresses per I2C specification: |
899 | * 0x00 General call address / START byte |
900 | * 0x01 CBUS address |
901 | * 0x02 Reserved for different bus format |
902 | * 0x03 Reserved for future purposes |
903 | * 0x04-0x07 Hs-mode master code |
904 | * 0x78-0x7b 10-bit slave addressing |
905 | * 0x7c-0x7f Reserved for future purposes |
906 | */ |
907 | if (addr < 0x08 || addr > 0x77) |
908 | return -EINVAL; |
909 | return 0; |
910 | } |
911 | |
912 | static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
913 | { |
914 | struct i2c_client *client = i2c_verify_client(dev); |
915 | int addr = *(int *)addrp; |
916 | |
917 | if (client && client->addr == addr) |
918 | return -EBUSY; |
919 | return 0; |
920 | } |
921 | |
922 | /* walk up mux tree */ |
923 | static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) |
924 | { |
925 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
926 | int result; |
927 | |
928 | result = device_for_each_child(&adapter->dev, &addr, |
929 | __i2c_check_addr_busy); |
930 | |
931 | if (!result && parent) |
932 | result = i2c_check_mux_parents(parent, addr); |
933 | |
934 | return result; |
935 | } |
936 | |
937 | /* recurse down mux tree */ |
938 | static int i2c_check_mux_children(struct device *dev, void *addrp) |
939 | { |
940 | int result; |
941 | |
942 | if (dev->type == &i2c_adapter_type) |
943 | result = device_for_each_child(dev, addrp, |
944 | i2c_check_mux_children); |
945 | else |
946 | result = __i2c_check_addr_busy(dev, addrp); |
947 | |
948 | return result; |
949 | } |
950 | |
951 | static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) |
952 | { |
953 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
954 | int result = 0; |
955 | |
956 | if (parent) |
957 | result = i2c_check_mux_parents(parent, addr); |
958 | |
959 | if (!result) |
960 | result = device_for_each_child(&adapter->dev, &addr, |
961 | i2c_check_mux_children); |
962 | |
963 | return result; |
964 | } |
965 | |
966 | /** |
967 | * i2c_lock_adapter - Get exclusive access to an I2C bus segment |
968 | * @adapter: Target I2C bus segment |
969 | */ |
970 | void i2c_lock_adapter(struct i2c_adapter *adapter) |
971 | { |
972 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
973 | |
974 | if (parent) |
975 | i2c_lock_adapter(parent); |
976 | else |
977 | rt_mutex_lock(&adapter->bus_lock); |
978 | } |
979 | EXPORT_SYMBOL_GPL(i2c_lock_adapter); |
980 | |
981 | /** |
982 | * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment |
983 | * @adapter: Target I2C bus segment |
984 | */ |
985 | static int i2c_trylock_adapter(struct i2c_adapter *adapter) |
986 | { |
987 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
988 | |
989 | if (parent) |
990 | return i2c_trylock_adapter(parent); |
991 | else |
992 | return rt_mutex_trylock(&adapter->bus_lock); |
993 | } |
994 | |
995 | /** |
996 | * i2c_unlock_adapter - Release exclusive access to an I2C bus segment |
997 | * @adapter: Target I2C bus segment |
998 | */ |
999 | void i2c_unlock_adapter(struct i2c_adapter *adapter) |
1000 | { |
1001 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
1002 | |
1003 | if (parent) |
1004 | i2c_unlock_adapter(parent); |
1005 | else |
1006 | rt_mutex_unlock(&adapter->bus_lock); |
1007 | } |
1008 | EXPORT_SYMBOL_GPL(i2c_unlock_adapter); |
1009 | |
1010 | static void i2c_dev_set_name(struct i2c_adapter *adap, |
1011 | struct i2c_client *client) |
1012 | { |
1013 | struct acpi_device *adev = ACPI_COMPANION(&client->dev); |
1014 | |
1015 | if (adev) { |
1016 | dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); |
1017 | return; |
1018 | } |
1019 | |
1020 | /* For 10-bit clients, add an arbitrary offset to avoid collisions */ |
1021 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), |
1022 | client->addr | ((client->flags & I2C_CLIENT_TEN) |
1023 | ? 0xa000 : 0)); |
1024 | } |
1025 | |
1026 | /** |
1027 | * i2c_new_device - instantiate an i2c device |
1028 | * @adap: the adapter managing the device |
1029 | * @info: describes one I2C device; bus_num is ignored |
1030 | * Context: can sleep |
1031 | * |
1032 | * Create an i2c device. Binding is handled through driver model |
1033 | * probe()/remove() methods. A driver may be bound to this device when we |
1034 | * return from this function, or any later moment (e.g. maybe hotplugging will |
1035 | * load the driver module). This call is not appropriate for use by mainboard |
1036 | * initialization logic, which usually runs during an arch_initcall() long |
1037 | * before any i2c_adapter could exist. |
1038 | * |
1039 | * This returns the new i2c client, which may be saved for later use with |
1040 | * i2c_unregister_device(); or NULL to indicate an error. |
1041 | */ |
1042 | struct i2c_client * |
1043 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) |
1044 | { |
1045 | struct i2c_client *client; |
1046 | int status; |
1047 | |
1048 | client = kzalloc(sizeof *client, GFP_KERNEL); |
1049 | if (!client) |
1050 | return NULL; |
1051 | |
1052 | client->adapter = adap; |
1053 | |
1054 | client->dev.platform_data = info->platform_data; |
1055 | |
1056 | if (info->archdata) |
1057 | client->dev.archdata = *info->archdata; |
1058 | |
1059 | client->flags = info->flags; |
1060 | client->addr = info->addr; |
1061 | client->irq = info->irq; |
1062 | |
1063 | strlcpy(client->name, info->type, sizeof(client->name)); |
1064 | |
1065 | /* Check for address validity */ |
1066 | status = i2c_check_client_addr_validity(client); |
1067 | if (status) { |
1068 | dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", |
1069 | client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); |
1070 | goto out_err_silent; |
1071 | } |
1072 | |
1073 | /* Check for address business */ |
1074 | status = i2c_check_addr_busy(adap, client->addr); |
1075 | if (status) |
1076 | goto out_err; |
1077 | |
1078 | client->dev.parent = &client->adapter->dev; |
1079 | client->dev.bus = &i2c_bus_type; |
1080 | client->dev.type = &i2c_client_type; |
1081 | client->dev.of_node = info->of_node; |
1082 | ACPI_COMPANION_SET(&client->dev, info->acpi_node.companion); |
1083 | |
1084 | i2c_dev_set_name(adap, client); |
1085 | status = device_register(&client->dev); |
1086 | if (status) |
1087 | goto out_err; |
1088 | |
1089 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
1090 | client->name, dev_name(&client->dev)); |
1091 | |
1092 | return client; |
1093 | |
1094 | out_err: |
1095 | dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " |
1096 | "(%d)\n", client->name, client->addr, status); |
1097 | out_err_silent: |
1098 | kfree(client); |
1099 | return NULL; |
1100 | } |
1101 | EXPORT_SYMBOL_GPL(i2c_new_device); |
1102 | |
1103 | |
1104 | /** |
1105 | * i2c_unregister_device - reverse effect of i2c_new_device() |
1106 | * @client: value returned from i2c_new_device() |
1107 | * Context: can sleep |
1108 | */ |
1109 | void i2c_unregister_device(struct i2c_client *client) |
1110 | { |
1111 | device_unregister(&client->dev); |
1112 | } |
1113 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
1114 | |
1115 | |
1116 | static const struct i2c_device_id dummy_id[] = { |
1117 | { "dummy", 0 }, |
1118 | { }, |
1119 | }; |
1120 | |
1121 | static int dummy_probe(struct i2c_client *client, |
1122 | const struct i2c_device_id *id) |
1123 | { |
1124 | return 0; |
1125 | } |
1126 | |
1127 | static int dummy_remove(struct i2c_client *client) |
1128 | { |
1129 | return 0; |
1130 | } |
1131 | |
1132 | static struct i2c_driver dummy_driver = { |
1133 | .driver.name = "dummy", |
1134 | .probe = dummy_probe, |
1135 | .remove = dummy_remove, |
1136 | .id_table = dummy_id, |
1137 | }; |
1138 | |
1139 | /** |
1140 | * i2c_new_dummy - return a new i2c device bound to a dummy driver |
1141 | * @adapter: the adapter managing the device |
1142 | * @address: seven bit address to be used |
1143 | * Context: can sleep |
1144 | * |
1145 | * This returns an I2C client bound to the "dummy" driver, intended for use |
1146 | * with devices that consume multiple addresses. Examples of such chips |
1147 | * include various EEPROMS (like 24c04 and 24c08 models). |
1148 | * |
1149 | * These dummy devices have two main uses. First, most I2C and SMBus calls |
1150 | * except i2c_transfer() need a client handle; the dummy will be that handle. |
1151 | * And second, this prevents the specified address from being bound to a |
1152 | * different driver. |
1153 | * |
1154 | * This returns the new i2c client, which should be saved for later use with |
1155 | * i2c_unregister_device(); or NULL to indicate an error. |
1156 | */ |
1157 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
1158 | { |
1159 | struct i2c_board_info info = { |
1160 | I2C_BOARD_INFO("dummy", address), |
1161 | }; |
1162 | |
1163 | return i2c_new_device(adapter, &info); |
1164 | } |
1165 | EXPORT_SYMBOL_GPL(i2c_new_dummy); |
1166 | |
1167 | /* ------------------------------------------------------------------------- */ |
1168 | |
1169 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
1170 | |
1171 | static void i2c_adapter_dev_release(struct device *dev) |
1172 | { |
1173 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1174 | complete(&adap->dev_released); |
1175 | } |
1176 | |
1177 | /* |
1178 | * This function is only needed for mutex_lock_nested, so it is never |
1179 | * called unless locking correctness checking is enabled. Thus we |
1180 | * make it inline to avoid a compiler warning. That's what gcc ends up |
1181 | * doing anyway. |
1182 | */ |
1183 | static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) |
1184 | { |
1185 | unsigned int depth = 0; |
1186 | |
1187 | while ((adapter = i2c_parent_is_i2c_adapter(adapter))) |
1188 | depth++; |
1189 | |
1190 | return depth; |
1191 | } |
1192 | |
1193 | /* |
1194 | * Let users instantiate I2C devices through sysfs. This can be used when |
1195 | * platform initialization code doesn't contain the proper data for |
1196 | * whatever reason. Also useful for drivers that do device detection and |
1197 | * detection fails, either because the device uses an unexpected address, |
1198 | * or this is a compatible device with different ID register values. |
1199 | * |
1200 | * Parameter checking may look overzealous, but we really don't want |
1201 | * the user to provide incorrect parameters. |
1202 | */ |
1203 | static ssize_t |
1204 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, |
1205 | const char *buf, size_t count) |
1206 | { |
1207 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1208 | struct i2c_board_info info; |
1209 | struct i2c_client *client; |
1210 | char *blank, end; |
1211 | int res; |
1212 | |
1213 | memset(&info, 0, sizeof(struct i2c_board_info)); |
1214 | |
1215 | blank = strchr(buf, ' '); |
1216 | if (!blank) { |
1217 | dev_err(dev, "%s: Missing parameters\n", "new_device"); |
1218 | return -EINVAL; |
1219 | } |
1220 | if (blank - buf > I2C_NAME_SIZE - 1) { |
1221 | dev_err(dev, "%s: Invalid device name\n", "new_device"); |
1222 | return -EINVAL; |
1223 | } |
1224 | memcpy(info.type, buf, blank - buf); |
1225 | |
1226 | /* Parse remaining parameters, reject extra parameters */ |
1227 | res = sscanf(++blank, "%hi%c", &info.addr, &end); |
1228 | if (res < 1) { |
1229 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); |
1230 | return -EINVAL; |
1231 | } |
1232 | if (res > 1 && end != '\n') { |
1233 | dev_err(dev, "%s: Extra parameters\n", "new_device"); |
1234 | return -EINVAL; |
1235 | } |
1236 | |
1237 | client = i2c_new_device(adap, &info); |
1238 | if (!client) |
1239 | return -EINVAL; |
1240 | |
1241 | /* Keep track of the added device */ |
1242 | mutex_lock(&adap->userspace_clients_lock); |
1243 | list_add_tail(&client->detected, &adap->userspace_clients); |
1244 | mutex_unlock(&adap->userspace_clients_lock); |
1245 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
1246 | info.type, info.addr); |
1247 | |
1248 | return count; |
1249 | } |
1250 | |
1251 | /* |
1252 | * And of course let the users delete the devices they instantiated, if |
1253 | * they got it wrong. This interface can only be used to delete devices |
1254 | * instantiated by i2c_sysfs_new_device above. This guarantees that we |
1255 | * don't delete devices to which some kernel code still has references. |
1256 | * |
1257 | * Parameter checking may look overzealous, but we really don't want |
1258 | * the user to delete the wrong device. |
1259 | */ |
1260 | static ssize_t |
1261 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, |
1262 | const char *buf, size_t count) |
1263 | { |
1264 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1265 | struct i2c_client *client, *next; |
1266 | unsigned short addr; |
1267 | char end; |
1268 | int res; |
1269 | |
1270 | /* Parse parameters, reject extra parameters */ |
1271 | res = sscanf(buf, "%hi%c", &addr, &end); |
1272 | if (res < 1) { |
1273 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); |
1274 | return -EINVAL; |
1275 | } |
1276 | if (res > 1 && end != '\n') { |
1277 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); |
1278 | return -EINVAL; |
1279 | } |
1280 | |
1281 | /* Make sure the device was added through sysfs */ |
1282 | res = -ENOENT; |
1283 | mutex_lock_nested(&adap->userspace_clients_lock, |
1284 | i2c_adapter_depth(adap)); |
1285 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1286 | detected) { |
1287 | if (client->addr == addr) { |
1288 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
1289 | "delete_device", client->name, client->addr); |
1290 | |
1291 | list_del(&client->detected); |
1292 | i2c_unregister_device(client); |
1293 | res = count; |
1294 | break; |
1295 | } |
1296 | } |
1297 | mutex_unlock(&adap->userspace_clients_lock); |
1298 | |
1299 | if (res < 0) |
1300 | dev_err(dev, "%s: Can't find device in list\n", |
1301 | "delete_device"); |
1302 | return res; |
1303 | } |
1304 | |
1305 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
1306 | static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, |
1307 | i2c_sysfs_delete_device); |
1308 | |
1309 | static struct attribute *i2c_adapter_attrs[] = { |
1310 | &dev_attr_name.attr, |
1311 | &dev_attr_new_device.attr, |
1312 | &dev_attr_delete_device.attr, |
1313 | NULL |
1314 | }; |
1315 | |
1316 | static struct attribute_group i2c_adapter_attr_group = { |
1317 | .attrs = i2c_adapter_attrs, |
1318 | }; |
1319 | |
1320 | static const struct attribute_group *i2c_adapter_attr_groups[] = { |
1321 | &i2c_adapter_attr_group, |
1322 | NULL |
1323 | }; |
1324 | |
1325 | struct device_type i2c_adapter_type = { |
1326 | .groups = i2c_adapter_attr_groups, |
1327 | .release = i2c_adapter_dev_release, |
1328 | }; |
1329 | EXPORT_SYMBOL_GPL(i2c_adapter_type); |
1330 | |
1331 | /** |
1332 | * i2c_verify_adapter - return parameter as i2c_adapter or NULL |
1333 | * @dev: device, probably from some driver model iterator |
1334 | * |
1335 | * When traversing the driver model tree, perhaps using driver model |
1336 | * iterators like @device_for_each_child(), you can't assume very much |
1337 | * about the nodes you find. Use this function to avoid oopses caused |
1338 | * by wrongly treating some non-I2C device as an i2c_adapter. |
1339 | */ |
1340 | struct i2c_adapter *i2c_verify_adapter(struct device *dev) |
1341 | { |
1342 | return (dev->type == &i2c_adapter_type) |
1343 | ? to_i2c_adapter(dev) |
1344 | : NULL; |
1345 | } |
1346 | EXPORT_SYMBOL(i2c_verify_adapter); |
1347 | |
1348 | #ifdef CONFIG_I2C_COMPAT |
1349 | static struct class_compat *i2c_adapter_compat_class; |
1350 | #endif |
1351 | |
1352 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
1353 | { |
1354 | struct i2c_devinfo *devinfo; |
1355 | |
1356 | down_read(&__i2c_board_lock); |
1357 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
1358 | if (devinfo->busnum == adapter->nr |
1359 | && !i2c_new_device(adapter, |
1360 | &devinfo->board_info)) |
1361 | dev_err(&adapter->dev, |
1362 | "Can't create device at 0x%02x\n", |
1363 | devinfo->board_info.addr); |
1364 | } |
1365 | up_read(&__i2c_board_lock); |
1366 | } |
1367 | |
1368 | /* OF support code */ |
1369 | |
1370 | #if IS_ENABLED(CONFIG_OF) |
1371 | static void of_i2c_register_devices(struct i2c_adapter *adap) |
1372 | { |
1373 | void *result; |
1374 | struct device_node *node; |
1375 | |
1376 | /* Only register child devices if the adapter has a node pointer set */ |
1377 | if (!adap->dev.of_node) |
1378 | return; |
1379 | |
1380 | dev_dbg(&adap->dev, "of_i2c: walking child nodes\n"); |
1381 | |
1382 | for_each_available_child_of_node(adap->dev.of_node, node) { |
1383 | struct i2c_board_info info = {}; |
1384 | struct dev_archdata dev_ad = {}; |
1385 | const __be32 *addr; |
1386 | int len; |
1387 | |
1388 | dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name); |
1389 | |
1390 | if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) { |
1391 | dev_err(&adap->dev, "of_i2c: modalias failure on %s\n", |
1392 | node->full_name); |
1393 | continue; |
1394 | } |
1395 | |
1396 | addr = of_get_property(node, "reg", &len); |
1397 | if (!addr || (len < sizeof(int))) { |
1398 | dev_err(&adap->dev, "of_i2c: invalid reg on %s\n", |
1399 | node->full_name); |
1400 | continue; |
1401 | } |
1402 | |
1403 | info.addr = be32_to_cpup(addr); |
1404 | if (info.addr > (1 << 10) - 1) { |
1405 | dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n", |
1406 | info.addr, node->full_name); |
1407 | continue; |
1408 | } |
1409 | |
1410 | info.irq = irq_of_parse_and_map(node, 0); |
1411 | info.of_node = of_node_get(node); |
1412 | info.archdata = &dev_ad; |
1413 | |
1414 | if (of_get_property(node, "wakeup-source", NULL)) |
1415 | info.flags |= I2C_CLIENT_WAKE; |
1416 | |
1417 | request_module("%s%s", I2C_MODULE_PREFIX, info.type); |
1418 | |
1419 | result = i2c_new_device(adap, &info); |
1420 | if (result == NULL) { |
1421 | dev_err(&adap->dev, "of_i2c: Failure registering %s\n", |
1422 | node->full_name); |
1423 | of_node_put(node); |
1424 | irq_dispose_mapping(info.irq); |
1425 | continue; |
1426 | } |
1427 | } |
1428 | } |
1429 | |
1430 | static int of_dev_node_match(struct device *dev, void *data) |
1431 | { |
1432 | return dev->of_node == data; |
1433 | } |
1434 | |
1435 | /* must call put_device() when done with returned i2c_client device */ |
1436 | struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) |
1437 | { |
1438 | struct device *dev; |
1439 | |
1440 | dev = bus_find_device(&i2c_bus_type, NULL, node, |
1441 | of_dev_node_match); |
1442 | if (!dev) |
1443 | return NULL; |
1444 | |
1445 | return i2c_verify_client(dev); |
1446 | } |
1447 | EXPORT_SYMBOL(of_find_i2c_device_by_node); |
1448 | |
1449 | /* must call put_device() when done with returned i2c_adapter device */ |
1450 | struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) |
1451 | { |
1452 | struct device *dev; |
1453 | |
1454 | dev = bus_find_device(&i2c_bus_type, NULL, node, |
1455 | of_dev_node_match); |
1456 | if (!dev) |
1457 | return NULL; |
1458 | |
1459 | return i2c_verify_adapter(dev); |
1460 | } |
1461 | EXPORT_SYMBOL(of_find_i2c_adapter_by_node); |
1462 | #else |
1463 | static void of_i2c_register_devices(struct i2c_adapter *adap) { } |
1464 | #endif /* CONFIG_OF */ |
1465 | |
1466 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
1467 | struct i2c_adapter *adap) |
1468 | { |
1469 | /* Detect supported devices on that bus, and instantiate them */ |
1470 | i2c_detect(adap, driver); |
1471 | |
1472 | /* Let legacy drivers scan this bus for matching devices */ |
1473 | if (driver->attach_adapter) { |
1474 | dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n", |
1475 | driver->driver.name); |
1476 | dev_warn(&adap->dev, "Please use another way to instantiate " |
1477 | "your i2c_client\n"); |
1478 | /* We ignore the return code; if it fails, too bad */ |
1479 | driver->attach_adapter(adap); |
1480 | } |
1481 | return 0; |
1482 | } |
1483 | |
1484 | static int __process_new_adapter(struct device_driver *d, void *data) |
1485 | { |
1486 | return i2c_do_add_adapter(to_i2c_driver(d), data); |
1487 | } |
1488 | |
1489 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1490 | { |
1491 | int res = 0; |
1492 | |
1493 | /* Can't register until after driver model init */ |
1494 | if (unlikely(WARN_ON(!i2c_bus_type.p))) { |
1495 | res = -EAGAIN; |
1496 | goto out_list; |
1497 | } |
1498 | |
1499 | /* Sanity checks */ |
1500 | if (unlikely(adap->name[0] == '\0')) { |
1501 | pr_err("i2c-core: Attempt to register an adapter with " |
1502 | "no name!\n"); |
1503 | return -EINVAL; |
1504 | } |
1505 | if (unlikely(!adap->algo)) { |
1506 | pr_err("i2c-core: Attempt to register adapter '%s' with " |
1507 | "no algo!\n", adap->name); |
1508 | return -EINVAL; |
1509 | } |
1510 | |
1511 | rt_mutex_init(&adap->bus_lock); |
1512 | mutex_init(&adap->userspace_clients_lock); |
1513 | INIT_LIST_HEAD(&adap->userspace_clients); |
1514 | |
1515 | /* Set default timeout to 1 second if not already set */ |
1516 | if (adap->timeout == 0) |
1517 | adap->timeout = HZ; |
1518 | |
1519 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
1520 | adap->dev.bus = &i2c_bus_type; |
1521 | adap->dev.type = &i2c_adapter_type; |
1522 | res = device_register(&adap->dev); |
1523 | if (res) |
1524 | goto out_list; |
1525 | |
1526 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
1527 | |
1528 | #ifdef CONFIG_I2C_COMPAT |
1529 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, |
1530 | adap->dev.parent); |
1531 | if (res) |
1532 | dev_warn(&adap->dev, |
1533 | "Failed to create compatibility class link\n"); |
1534 | #endif |
1535 | |
1536 | /* bus recovery specific initialization */ |
1537 | if (adap->bus_recovery_info) { |
1538 | struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; |
1539 | |
1540 | if (!bri->recover_bus) { |
1541 | dev_err(&adap->dev, "No recover_bus() found, not using recovery\n"); |
1542 | adap->bus_recovery_info = NULL; |
1543 | goto exit_recovery; |
1544 | } |
1545 | |
1546 | /* Generic GPIO recovery */ |
1547 | if (bri->recover_bus == i2c_generic_gpio_recovery) { |
1548 | if (!gpio_is_valid(bri->scl_gpio)) { |
1549 | dev_err(&adap->dev, "Invalid SCL gpio, not using recovery\n"); |
1550 | adap->bus_recovery_info = NULL; |
1551 | goto exit_recovery; |
1552 | } |
1553 | |
1554 | if (gpio_is_valid(bri->sda_gpio)) |
1555 | bri->get_sda = get_sda_gpio_value; |
1556 | else |
1557 | bri->get_sda = NULL; |
1558 | |
1559 | bri->get_scl = get_scl_gpio_value; |
1560 | bri->set_scl = set_scl_gpio_value; |
1561 | } else if (!bri->set_scl || !bri->get_scl) { |
1562 | /* Generic SCL recovery */ |
1563 | dev_err(&adap->dev, "No {get|set}_gpio() found, not using recovery\n"); |
1564 | adap->bus_recovery_info = NULL; |
1565 | } |
1566 | } |
1567 | |
1568 | exit_recovery: |
1569 | /* create pre-declared device nodes */ |
1570 | of_i2c_register_devices(adap); |
1571 | acpi_i2c_register_devices(adap); |
1572 | acpi_i2c_install_space_handler(adap); |
1573 | |
1574 | if (adap->nr < __i2c_first_dynamic_bus_num) |
1575 | i2c_scan_static_board_info(adap); |
1576 | |
1577 | /* Notify drivers */ |
1578 | mutex_lock(&core_lock); |
1579 | bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); |
1580 | mutex_unlock(&core_lock); |
1581 | |
1582 | return 0; |
1583 | |
1584 | out_list: |
1585 | mutex_lock(&core_lock); |
1586 | idr_remove(&i2c_adapter_idr, adap->nr); |
1587 | mutex_unlock(&core_lock); |
1588 | return res; |
1589 | } |
1590 | |
1591 | /** |
1592 | * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 |
1593 | * @adap: the adapter to register (with adap->nr initialized) |
1594 | * Context: can sleep |
1595 | * |
1596 | * See i2c_add_numbered_adapter() for details. |
1597 | */ |
1598 | static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) |
1599 | { |
1600 | int id; |
1601 | |
1602 | mutex_lock(&core_lock); |
1603 | id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, |
1604 | GFP_KERNEL); |
1605 | mutex_unlock(&core_lock); |
1606 | if (id < 0) |
1607 | return id == -ENOSPC ? -EBUSY : id; |
1608 | |
1609 | return i2c_register_adapter(adap); |
1610 | } |
1611 | |
1612 | /** |
1613 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number |
1614 | * @adapter: the adapter to add |
1615 | * Context: can sleep |
1616 | * |
1617 | * This routine is used to declare an I2C adapter when its bus number |
1618 | * doesn't matter or when its bus number is specified by an dt alias. |
1619 | * Examples of bases when the bus number doesn't matter: I2C adapters |
1620 | * dynamically added by USB links or PCI plugin cards. |
1621 | * |
1622 | * When this returns zero, a new bus number was allocated and stored |
1623 | * in adap->nr, and the specified adapter became available for clients. |
1624 | * Otherwise, a negative errno value is returned. |
1625 | */ |
1626 | int i2c_add_adapter(struct i2c_adapter *adapter) |
1627 | { |
1628 | struct device *dev = &adapter->dev; |
1629 | int id; |
1630 | |
1631 | if (dev->of_node) { |
1632 | id = of_alias_get_id(dev->of_node, "i2c"); |
1633 | if (id >= 0) { |
1634 | adapter->nr = id; |
1635 | return __i2c_add_numbered_adapter(adapter); |
1636 | } |
1637 | } |
1638 | |
1639 | mutex_lock(&core_lock); |
1640 | id = idr_alloc(&i2c_adapter_idr, adapter, |
1641 | __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); |
1642 | mutex_unlock(&core_lock); |
1643 | if (id < 0) |
1644 | return id; |
1645 | |
1646 | adapter->nr = id; |
1647 | |
1648 | return i2c_register_adapter(adapter); |
1649 | } |
1650 | EXPORT_SYMBOL(i2c_add_adapter); |
1651 | |
1652 | /** |
1653 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number |
1654 | * @adap: the adapter to register (with adap->nr initialized) |
1655 | * Context: can sleep |
1656 | * |
1657 | * This routine is used to declare an I2C adapter when its bus number |
1658 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
1659 | * or otherwise built in to the system's mainboard, and where i2c_board_info |
1660 | * is used to properly configure I2C devices. |
1661 | * |
1662 | * If the requested bus number is set to -1, then this function will behave |
1663 | * identically to i2c_add_adapter, and will dynamically assign a bus number. |
1664 | * |
1665 | * If no devices have pre-been declared for this bus, then be sure to |
1666 | * register the adapter before any dynamically allocated ones. Otherwise |
1667 | * the required bus ID may not be available. |
1668 | * |
1669 | * When this returns zero, the specified adapter became available for |
1670 | * clients using the bus number provided in adap->nr. Also, the table |
1671 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, |
1672 | * and the appropriate driver model device nodes are created. Otherwise, a |
1673 | * negative errno value is returned. |
1674 | */ |
1675 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) |
1676 | { |
1677 | if (adap->nr == -1) /* -1 means dynamically assign bus id */ |
1678 | return i2c_add_adapter(adap); |
1679 | |
1680 | return __i2c_add_numbered_adapter(adap); |
1681 | } |
1682 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); |
1683 | |
1684 | static void i2c_do_del_adapter(struct i2c_driver *driver, |
1685 | struct i2c_adapter *adapter) |
1686 | { |
1687 | struct i2c_client *client, *_n; |
1688 | |
1689 | /* Remove the devices we created ourselves as the result of hardware |
1690 | * probing (using a driver's detect method) */ |
1691 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
1692 | if (client->adapter == adapter) { |
1693 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", |
1694 | client->name, client->addr); |
1695 | list_del(&client->detected); |
1696 | i2c_unregister_device(client); |
1697 | } |
1698 | } |
1699 | } |
1700 | |
1701 | static int __unregister_client(struct device *dev, void *dummy) |
1702 | { |
1703 | struct i2c_client *client = i2c_verify_client(dev); |
1704 | if (client && strcmp(client->name, "dummy")) |
1705 | i2c_unregister_device(client); |
1706 | return 0; |
1707 | } |
1708 | |
1709 | static int __unregister_dummy(struct device *dev, void *dummy) |
1710 | { |
1711 | struct i2c_client *client = i2c_verify_client(dev); |
1712 | if (client) |
1713 | i2c_unregister_device(client); |
1714 | return 0; |
1715 | } |
1716 | |
1717 | static int __process_removed_adapter(struct device_driver *d, void *data) |
1718 | { |
1719 | i2c_do_del_adapter(to_i2c_driver(d), data); |
1720 | return 0; |
1721 | } |
1722 | |
1723 | /** |
1724 | * i2c_del_adapter - unregister I2C adapter |
1725 | * @adap: the adapter being unregistered |
1726 | * Context: can sleep |
1727 | * |
1728 | * This unregisters an I2C adapter which was previously registered |
1729 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. |
1730 | */ |
1731 | void i2c_del_adapter(struct i2c_adapter *adap) |
1732 | { |
1733 | struct i2c_adapter *found; |
1734 | struct i2c_client *client, *next; |
1735 | |
1736 | /* First make sure that this adapter was ever added */ |
1737 | mutex_lock(&core_lock); |
1738 | found = idr_find(&i2c_adapter_idr, adap->nr); |
1739 | mutex_unlock(&core_lock); |
1740 | if (found != adap) { |
1741 | pr_debug("i2c-core: attempting to delete unregistered " |
1742 | "adapter [%s]\n", adap->name); |
1743 | return; |
1744 | } |
1745 | |
1746 | acpi_i2c_remove_space_handler(adap); |
1747 | /* Tell drivers about this removal */ |
1748 | mutex_lock(&core_lock); |
1749 | bus_for_each_drv(&i2c_bus_type, NULL, adap, |
1750 | __process_removed_adapter); |
1751 | mutex_unlock(&core_lock); |
1752 | |
1753 | /* Remove devices instantiated from sysfs */ |
1754 | mutex_lock_nested(&adap->userspace_clients_lock, |
1755 | i2c_adapter_depth(adap)); |
1756 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1757 | detected) { |
1758 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, |
1759 | client->addr); |
1760 | list_del(&client->detected); |
1761 | i2c_unregister_device(client); |
1762 | } |
1763 | mutex_unlock(&adap->userspace_clients_lock); |
1764 | |
1765 | /* Detach any active clients. This can't fail, thus we do not |
1766 | * check the returned value. This is a two-pass process, because |
1767 | * we can't remove the dummy devices during the first pass: they |
1768 | * could have been instantiated by real devices wishing to clean |
1769 | * them up properly, so we give them a chance to do that first. */ |
1770 | device_for_each_child(&adap->dev, NULL, __unregister_client); |
1771 | device_for_each_child(&adap->dev, NULL, __unregister_dummy); |
1772 | |
1773 | #ifdef CONFIG_I2C_COMPAT |
1774 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, |
1775 | adap->dev.parent); |
1776 | #endif |
1777 | |
1778 | /* device name is gone after device_unregister */ |
1779 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); |
1780 | |
1781 | /* clean up the sysfs representation */ |
1782 | init_completion(&adap->dev_released); |
1783 | device_unregister(&adap->dev); |
1784 | |
1785 | /* wait for sysfs to drop all references */ |
1786 | wait_for_completion(&adap->dev_released); |
1787 | |
1788 | /* free bus id */ |
1789 | mutex_lock(&core_lock); |
1790 | idr_remove(&i2c_adapter_idr, adap->nr); |
1791 | mutex_unlock(&core_lock); |
1792 | |
1793 | /* Clear the device structure in case this adapter is ever going to be |
1794 | added again */ |
1795 | memset(&adap->dev, 0, sizeof(adap->dev)); |
1796 | } |
1797 | EXPORT_SYMBOL(i2c_del_adapter); |
1798 | |
1799 | /* ------------------------------------------------------------------------- */ |
1800 | |
1801 | int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) |
1802 | { |
1803 | int res; |
1804 | |
1805 | mutex_lock(&core_lock); |
1806 | res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); |
1807 | mutex_unlock(&core_lock); |
1808 | |
1809 | return res; |
1810 | } |
1811 | EXPORT_SYMBOL_GPL(i2c_for_each_dev); |
1812 | |
1813 | static int __process_new_driver(struct device *dev, void *data) |
1814 | { |
1815 | if (dev->type != &i2c_adapter_type) |
1816 | return 0; |
1817 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
1818 | } |
1819 | |
1820 | /* |
1821 | * An i2c_driver is used with one or more i2c_client (device) nodes to access |
1822 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1823 | */ |
1824 | |
1825 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1826 | { |
1827 | int res; |
1828 | |
1829 | /* Can't register until after driver model init */ |
1830 | if (unlikely(WARN_ON(!i2c_bus_type.p))) |
1831 | return -EAGAIN; |
1832 | |
1833 | /* add the driver to the list of i2c drivers in the driver core */ |
1834 | driver->driver.owner = owner; |
1835 | driver->driver.bus = &i2c_bus_type; |
1836 | |
1837 | /* When registration returns, the driver core |
1838 | * will have called probe() for all matching-but-unbound devices. |
1839 | */ |
1840 | res = driver_register(&driver->driver); |
1841 | if (res) |
1842 | return res; |
1843 | |
1844 | /* Drivers should switch to dev_pm_ops instead. */ |
1845 | if (driver->suspend) |
1846 | pr_warn("i2c-core: driver [%s] using legacy suspend method\n", |
1847 | driver->driver.name); |
1848 | if (driver->resume) |
1849 | pr_warn("i2c-core: driver [%s] using legacy resume method\n", |
1850 | driver->driver.name); |
1851 | |
1852 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1853 | |
1854 | INIT_LIST_HEAD(&driver->clients); |
1855 | /* Walk the adapters that are already present */ |
1856 | i2c_for_each_dev(driver, __process_new_driver); |
1857 | |
1858 | return 0; |
1859 | } |
1860 | EXPORT_SYMBOL(i2c_register_driver); |
1861 | |
1862 | static int __process_removed_driver(struct device *dev, void *data) |
1863 | { |
1864 | if (dev->type == &i2c_adapter_type) |
1865 | i2c_do_del_adapter(data, to_i2c_adapter(dev)); |
1866 | return 0; |
1867 | } |
1868 | |
1869 | /** |
1870 | * i2c_del_driver - unregister I2C driver |
1871 | * @driver: the driver being unregistered |
1872 | * Context: can sleep |
1873 | */ |
1874 | void i2c_del_driver(struct i2c_driver *driver) |
1875 | { |
1876 | i2c_for_each_dev(driver, __process_removed_driver); |
1877 | |
1878 | driver_unregister(&driver->driver); |
1879 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1880 | } |
1881 | EXPORT_SYMBOL(i2c_del_driver); |
1882 | |
1883 | /* ------------------------------------------------------------------------- */ |
1884 | |
1885 | /** |
1886 | * i2c_use_client - increments the reference count of the i2c client structure |
1887 | * @client: the client being referenced |
1888 | * |
1889 | * Each live reference to a client should be refcounted. The driver model does |
1890 | * that automatically as part of driver binding, so that most drivers don't |
1891 | * need to do this explicitly: they hold a reference until they're unbound |
1892 | * from the device. |
1893 | * |
1894 | * A pointer to the client with the incremented reference counter is returned. |
1895 | */ |
1896 | struct i2c_client *i2c_use_client(struct i2c_client *client) |
1897 | { |
1898 | if (client && get_device(&client->dev)) |
1899 | return client; |
1900 | return NULL; |
1901 | } |
1902 | EXPORT_SYMBOL(i2c_use_client); |
1903 | |
1904 | /** |
1905 | * i2c_release_client - release a use of the i2c client structure |
1906 | * @client: the client being no longer referenced |
1907 | * |
1908 | * Must be called when a user of a client is finished with it. |
1909 | */ |
1910 | void i2c_release_client(struct i2c_client *client) |
1911 | { |
1912 | if (client) |
1913 | put_device(&client->dev); |
1914 | } |
1915 | EXPORT_SYMBOL(i2c_release_client); |
1916 | |
1917 | struct i2c_cmd_arg { |
1918 | unsigned cmd; |
1919 | void *arg; |
1920 | }; |
1921 | |
1922 | static int i2c_cmd(struct device *dev, void *_arg) |
1923 | { |
1924 | struct i2c_client *client = i2c_verify_client(dev); |
1925 | struct i2c_cmd_arg *arg = _arg; |
1926 | struct i2c_driver *driver; |
1927 | |
1928 | if (!client || !client->dev.driver) |
1929 | return 0; |
1930 | |
1931 | driver = to_i2c_driver(client->dev.driver); |
1932 | if (driver->command) |
1933 | driver->command(client, arg->cmd, arg->arg); |
1934 | return 0; |
1935 | } |
1936 | |
1937 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
1938 | { |
1939 | struct i2c_cmd_arg cmd_arg; |
1940 | |
1941 | cmd_arg.cmd = cmd; |
1942 | cmd_arg.arg = arg; |
1943 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); |
1944 | } |
1945 | EXPORT_SYMBOL(i2c_clients_command); |
1946 | |
1947 | static int __init i2c_init(void) |
1948 | { |
1949 | int retval; |
1950 | |
1951 | retval = bus_register(&i2c_bus_type); |
1952 | if (retval) |
1953 | return retval; |
1954 | #ifdef CONFIG_I2C_COMPAT |
1955 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); |
1956 | if (!i2c_adapter_compat_class) { |
1957 | retval = -ENOMEM; |
1958 | goto bus_err; |
1959 | } |
1960 | #endif |
1961 | retval = i2c_add_driver(&dummy_driver); |
1962 | if (retval) |
1963 | goto class_err; |
1964 | return 0; |
1965 | |
1966 | class_err: |
1967 | #ifdef CONFIG_I2C_COMPAT |
1968 | class_compat_unregister(i2c_adapter_compat_class); |
1969 | bus_err: |
1970 | #endif |
1971 | bus_unregister(&i2c_bus_type); |
1972 | return retval; |
1973 | } |
1974 | |
1975 | static void __exit i2c_exit(void) |
1976 | { |
1977 | i2c_del_driver(&dummy_driver); |
1978 | #ifdef CONFIG_I2C_COMPAT |
1979 | class_compat_unregister(i2c_adapter_compat_class); |
1980 | #endif |
1981 | bus_unregister(&i2c_bus_type); |
1982 | tracepoint_synchronize_unregister(); |
1983 | } |
1984 | |
1985 | /* We must initialize early, because some subsystems register i2c drivers |
1986 | * in subsys_initcall() code, but are linked (and initialized) before i2c. |
1987 | */ |
1988 | postcore_initcall(i2c_init); |
1989 | module_exit(i2c_exit); |
1990 | |
1991 | /* ---------------------------------------------------- |
1992 | * the functional interface to the i2c busses. |
1993 | * ---------------------------------------------------- |
1994 | */ |
1995 | |
1996 | /** |
1997 | * __i2c_transfer - unlocked flavor of i2c_transfer |
1998 | * @adap: Handle to I2C bus |
1999 | * @msgs: One or more messages to execute before STOP is issued to |
2000 | * terminate the operation; each message begins with a START. |
2001 | * @num: Number of messages to be executed. |
2002 | * |
2003 | * Returns negative errno, else the number of messages executed. |
2004 | * |
2005 | * Adapter lock must be held when calling this function. No debug logging |
2006 | * takes place. adap->algo->master_xfer existence isn't checked. |
2007 | */ |
2008 | int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
2009 | { |
2010 | unsigned long orig_jiffies; |
2011 | int ret, try; |
2012 | |
2013 | /* i2c_trace_msg gets enabled when tracepoint i2c_transfer gets |
2014 | * enabled. This is an efficient way of keeping the for-loop from |
2015 | * being executed when not needed. |
2016 | */ |
2017 | if (static_key_false(&i2c_trace_msg)) { |
2018 | int i; |
2019 | for (i = 0; i < num; i++) |
2020 | if (msgs[i].flags & I2C_M_RD) |
2021 | trace_i2c_read(adap, &msgs[i], i); |
2022 | else |
2023 | trace_i2c_write(adap, &msgs[i], i); |
2024 | } |
2025 | |
2026 | /* Retry automatically on arbitration loss */ |
2027 | orig_jiffies = jiffies; |
2028 | for (ret = 0, try = 0; try <= adap->retries; try++) { |
2029 | ret = adap->algo->master_xfer(adap, msgs, num); |
2030 | if (ret != -EAGAIN) |
2031 | break; |
2032 | if (time_after(jiffies, orig_jiffies + adap->timeout)) |
2033 | break; |
2034 | } |
2035 | |
2036 | if (static_key_false(&i2c_trace_msg)) { |
2037 | int i; |
2038 | for (i = 0; i < ret; i++) |
2039 | if (msgs[i].flags & I2C_M_RD) |
2040 | trace_i2c_reply(adap, &msgs[i], i); |
2041 | trace_i2c_result(adap, i, ret); |
2042 | } |
2043 | |
2044 | return ret; |
2045 | } |
2046 | EXPORT_SYMBOL(__i2c_transfer); |
2047 | |
2048 | /** |
2049 | * i2c_transfer - execute a single or combined I2C message |
2050 | * @adap: Handle to I2C bus |
2051 | * @msgs: One or more messages to execute before STOP is issued to |
2052 | * terminate the operation; each message begins with a START. |
2053 | * @num: Number of messages to be executed. |
2054 | * |
2055 | * Returns negative errno, else the number of messages executed. |
2056 | * |
2057 | * Note that there is no requirement that each message be sent to |
2058 | * the same slave address, although that is the most common model. |
2059 | */ |
2060 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
2061 | { |
2062 | int ret; |
2063 | |
2064 | /* REVISIT the fault reporting model here is weak: |
2065 | * |
2066 | * - When we get an error after receiving N bytes from a slave, |
2067 | * there is no way to report "N". |
2068 | * |
2069 | * - When we get a NAK after transmitting N bytes to a slave, |
2070 | * there is no way to report "N" ... or to let the master |
2071 | * continue executing the rest of this combined message, if |
2072 | * that's the appropriate response. |
2073 | * |
2074 | * - When for example "num" is two and we successfully complete |
2075 | * the first message but get an error part way through the |
2076 | * second, it's unclear whether that should be reported as |
2077 | * one (discarding status on the second message) or errno |
2078 | * (discarding status on the first one). |
2079 | */ |
2080 | |
2081 | if (adap->algo->master_xfer) { |
2082 | #ifdef DEBUG |
2083 | for (ret = 0; ret < num; ret++) { |
2084 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " |
2085 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
2086 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, |
2087 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); |
2088 | } |
2089 | #endif |
2090 | |
2091 | if (in_atomic() || irqs_disabled()) { |
2092 | ret = i2c_trylock_adapter(adap); |
2093 | if (!ret) |
2094 | /* I2C activity is ongoing. */ |
2095 | return -EAGAIN; |
2096 | } else { |
2097 | i2c_lock_adapter(adap); |
2098 | } |
2099 | |
2100 | ret = __i2c_transfer(adap, msgs, num); |
2101 | i2c_unlock_adapter(adap); |
2102 | |
2103 | return ret; |
2104 | } else { |
2105 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); |
2106 | return -EOPNOTSUPP; |
2107 | } |
2108 | } |
2109 | EXPORT_SYMBOL(i2c_transfer); |
2110 | |
2111 | /** |
2112 | * i2c_master_send - issue a single I2C message in master transmit mode |
2113 | * @client: Handle to slave device |
2114 | * @buf: Data that will be written to the slave |
2115 | * @count: How many bytes to write, must be less than 64k since msg.len is u16 |
2116 | * |
2117 | * Returns negative errno, or else the number of bytes written. |
2118 | */ |
2119 | int i2c_master_send(const struct i2c_client *client, const char *buf, int count) |
2120 | { |
2121 | int ret; |
2122 | struct i2c_adapter *adap = client->adapter; |
2123 | struct i2c_msg msg; |
2124 | |
2125 | msg.addr = client->addr; |
2126 | msg.flags = client->flags & I2C_M_TEN; |
2127 | msg.len = count; |
2128 | msg.buf = (char *)buf; |
2129 | |
2130 | ret = i2c_transfer(adap, &msg, 1); |
2131 | |
2132 | /* |
2133 | * If everything went ok (i.e. 1 msg transmitted), return #bytes |
2134 | * transmitted, else error code. |
2135 | */ |
2136 | return (ret == 1) ? count : ret; |
2137 | } |
2138 | EXPORT_SYMBOL(i2c_master_send); |
2139 | |
2140 | /** |
2141 | * i2c_master_recv - issue a single I2C message in master receive mode |
2142 | * @client: Handle to slave device |
2143 | * @buf: Where to store data read from slave |
2144 | * @count: How many bytes to read, must be less than 64k since msg.len is u16 |
2145 | * |
2146 | * Returns negative errno, or else the number of bytes read. |
2147 | */ |
2148 | int i2c_master_recv(const struct i2c_client *client, char *buf, int count) |
2149 | { |
2150 | struct i2c_adapter *adap = client->adapter; |
2151 | struct i2c_msg msg; |
2152 | int ret; |
2153 | |
2154 | msg.addr = client->addr; |
2155 | msg.flags = client->flags & I2C_M_TEN; |
2156 | msg.flags |= I2C_M_RD; |
2157 | msg.len = count; |
2158 | msg.buf = buf; |
2159 | |
2160 | ret = i2c_transfer(adap, &msg, 1); |
2161 | |
2162 | /* |
2163 | * If everything went ok (i.e. 1 msg received), return #bytes received, |
2164 | * else error code. |
2165 | */ |
2166 | return (ret == 1) ? count : ret; |
2167 | } |
2168 | EXPORT_SYMBOL(i2c_master_recv); |
2169 | |
2170 | /* ---------------------------------------------------- |
2171 | * the i2c address scanning function |
2172 | * Will not work for 10-bit addresses! |
2173 | * ---------------------------------------------------- |
2174 | */ |
2175 | |
2176 | /* |
2177 | * Legacy default probe function, mostly relevant for SMBus. The default |
2178 | * probe method is a quick write, but it is known to corrupt the 24RF08 |
2179 | * EEPROMs due to a state machine bug, and could also irreversibly |
2180 | * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, |
2181 | * we use a short byte read instead. Also, some bus drivers don't implement |
2182 | * quick write, so we fallback to a byte read in that case too. |
2183 | * On x86, there is another special case for FSC hardware monitoring chips, |
2184 | * which want regular byte reads (address 0x73.) Fortunately, these are the |
2185 | * only known chips using this I2C address on PC hardware. |
2186 | * Returns 1 if probe succeeded, 0 if not. |
2187 | */ |
2188 | static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) |
2189 | { |
2190 | int err; |
2191 | union i2c_smbus_data dummy; |
2192 | |
2193 | #ifdef CONFIG_X86 |
2194 | if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) |
2195 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) |
2196 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, |
2197 | I2C_SMBUS_BYTE_DATA, &dummy); |
2198 | else |
2199 | #endif |
2200 | if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) |
2201 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) |
2202 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, |
2203 | I2C_SMBUS_QUICK, NULL); |
2204 | else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) |
2205 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, |
2206 | I2C_SMBUS_BYTE, &dummy); |
2207 | else { |
2208 | dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", |
2209 | addr); |
2210 | err = -EOPNOTSUPP; |
2211 | } |
2212 | |
2213 | return err >= 0; |
2214 | } |
2215 | |
2216 | static int i2c_detect_address(struct i2c_client *temp_client, |
2217 | struct i2c_driver *driver) |
2218 | { |
2219 | struct i2c_board_info info; |
2220 | struct i2c_adapter *adapter = temp_client->adapter; |
2221 | int addr = temp_client->addr; |
2222 | int err; |
2223 | |
2224 | /* Make sure the address is valid */ |
2225 | err = i2c_check_addr_validity(addr); |
2226 | if (err) { |
2227 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
2228 | addr); |
2229 | return err; |
2230 | } |
2231 | |
2232 | /* Skip if already in use */ |
2233 | if (i2c_check_addr_busy(adapter, addr)) |
2234 | return 0; |
2235 | |
2236 | /* Make sure there is something at this address */ |
2237 | if (!i2c_default_probe(adapter, addr)) |
2238 | return 0; |
2239 | |
2240 | /* Finally call the custom detection function */ |
2241 | memset(&info, 0, sizeof(struct i2c_board_info)); |
2242 | info.addr = addr; |
2243 | err = driver->detect(temp_client, &info); |
2244 | if (err) { |
2245 | /* -ENODEV is returned if the detection fails. We catch it |
2246 | here as this isn't an error. */ |
2247 | return err == -ENODEV ? 0 : err; |
2248 | } |
2249 | |
2250 | /* Consistency check */ |
2251 | if (info.type[0] == '\0') { |
2252 | dev_err(&adapter->dev, "%s detection function provided " |
2253 | "no name for 0x%x\n", driver->driver.name, |
2254 | addr); |
2255 | } else { |
2256 | struct i2c_client *client; |
2257 | |
2258 | /* Detection succeeded, instantiate the device */ |
2259 | if (adapter->class & I2C_CLASS_DEPRECATED) |
2260 | dev_warn(&adapter->dev, |
2261 | "This adapter will soon drop class based instantiation of devices. " |
2262 | "Please make sure client 0x%02x gets instantiated by other means. " |
2263 | "Check 'Documentation/i2c/instantiating-devices' for details.\n", |
2264 | info.addr); |
2265 | |
2266 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", |
2267 | info.type, info.addr); |
2268 | client = i2c_new_device(adapter, &info); |
2269 | if (client) |
2270 | list_add_tail(&client->detected, &driver->clients); |
2271 | else |
2272 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", |
2273 | info.type, info.addr); |
2274 | } |
2275 | return 0; |
2276 | } |
2277 | |
2278 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) |
2279 | { |
2280 | const unsigned short *address_list; |
2281 | struct i2c_client *temp_client; |
2282 | int i, err = 0; |
2283 | int adap_id = i2c_adapter_id(adapter); |
2284 | |
2285 | address_list = driver->address_list; |
2286 | if (!driver->detect || !address_list) |
2287 | return 0; |
2288 | |
2289 | /* Warn that the adapter lost class based instantiation */ |
2290 | if (adapter->class == I2C_CLASS_DEPRECATED) { |
2291 | dev_dbg(&adapter->dev, |
2292 | "This adapter dropped support for I2C classes and " |
2293 | "won't auto-detect %s devices anymore. If you need it, check " |
2294 | "'Documentation/i2c/instantiating-devices' for alternatives.\n", |
2295 | driver->driver.name); |
2296 | return 0; |
2297 | } |
2298 | |
2299 | /* Stop here if the classes do not match */ |
2300 | if (!(adapter->class & driver->class)) |
2301 | return 0; |
2302 | |
2303 | /* Set up a temporary client to help detect callback */ |
2304 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); |
2305 | if (!temp_client) |
2306 | return -ENOMEM; |
2307 | temp_client->adapter = adapter; |
2308 | |
2309 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
2310 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
2311 | "addr 0x%02x\n", adap_id, address_list[i]); |
2312 | temp_client->addr = address_list[i]; |
2313 | err = i2c_detect_address(temp_client, driver); |
2314 | if (unlikely(err)) |
2315 | break; |
2316 | } |
2317 | |
2318 | kfree(temp_client); |
2319 | return err; |
2320 | } |
2321 | |
2322 | int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) |
2323 | { |
2324 | return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, |
2325 | I2C_SMBUS_QUICK, NULL) >= 0; |
2326 | } |
2327 | EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); |
2328 | |
2329 | struct i2c_client * |
2330 | i2c_new_probed_device(struct i2c_adapter *adap, |
2331 | struct i2c_board_info *info, |
2332 | unsigned short const *addr_list, |
2333 | int (*probe)(struct i2c_adapter *, unsigned short addr)) |
2334 | { |
2335 | int i; |
2336 | |
2337 | if (!probe) |
2338 | probe = i2c_default_probe; |
2339 | |
2340 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
2341 | /* Check address validity */ |
2342 | if (i2c_check_addr_validity(addr_list[i]) < 0) { |
2343 | dev_warn(&adap->dev, "Invalid 7-bit address " |
2344 | "0x%02x\n", addr_list[i]); |
2345 | continue; |
2346 | } |
2347 | |
2348 | /* Check address availability */ |
2349 | if (i2c_check_addr_busy(adap, addr_list[i])) { |
2350 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
2351 | "use, not probing\n", addr_list[i]); |
2352 | continue; |
2353 | } |
2354 | |
2355 | /* Test address responsiveness */ |
2356 | if (probe(adap, addr_list[i])) |
2357 | break; |
2358 | } |
2359 | |
2360 | if (addr_list[i] == I2C_CLIENT_END) { |
2361 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); |
2362 | return NULL; |
2363 | } |
2364 | |
2365 | info->addr = addr_list[i]; |
2366 | return i2c_new_device(adap, info); |
2367 | } |
2368 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); |
2369 | |
2370 | struct i2c_adapter *i2c_get_adapter(int nr) |
2371 | { |
2372 | struct i2c_adapter *adapter; |
2373 | |
2374 | mutex_lock(&core_lock); |
2375 | adapter = idr_find(&i2c_adapter_idr, nr); |
2376 | if (adapter && !try_module_get(adapter->owner)) |
2377 | adapter = NULL; |
2378 | |
2379 | mutex_unlock(&core_lock); |
2380 | return adapter; |
2381 | } |
2382 | EXPORT_SYMBOL(i2c_get_adapter); |
2383 | |
2384 | void i2c_put_adapter(struct i2c_adapter *adap) |
2385 | { |
2386 | if (adap) |
2387 | module_put(adap->owner); |
2388 | } |
2389 | EXPORT_SYMBOL(i2c_put_adapter); |
2390 | |
2391 | /* The SMBus parts */ |
2392 | |
2393 | #define POLY (0x1070U << 3) |
2394 | static u8 crc8(u16 data) |
2395 | { |
2396 | int i; |
2397 | |
2398 | for (i = 0; i < 8; i++) { |
2399 | if (data & 0x8000) |
2400 | data = data ^ POLY; |
2401 | data = data << 1; |
2402 | } |
2403 | return (u8)(data >> 8); |
2404 | } |
2405 | |
2406 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
2407 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) |
2408 | { |
2409 | int i; |
2410 | |
2411 | for (i = 0; i < count; i++) |
2412 | crc = crc8((crc ^ p[i]) << 8); |
2413 | return crc; |
2414 | } |
2415 | |
2416 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
2417 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) |
2418 | { |
2419 | /* The address will be sent first */ |
2420 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); |
2421 | pec = i2c_smbus_pec(pec, &addr, 1); |
2422 | |
2423 | /* The data buffer follows */ |
2424 | return i2c_smbus_pec(pec, msg->buf, msg->len); |
2425 | } |
2426 | |
2427 | /* Used for write only transactions */ |
2428 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) |
2429 | { |
2430 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
2431 | msg->len++; |
2432 | } |
2433 | |
2434 | /* Return <0 on CRC error |
2435 | If there was a write before this read (most cases) we need to take the |
2436 | partial CRC from the write part into account. |
2437 | Note that this function does modify the message (we need to decrease the |
2438 | message length to hide the CRC byte from the caller). */ |
2439 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) |
2440 | { |
2441 | u8 rpec = msg->buf[--msg->len]; |
2442 | cpec = i2c_smbus_msg_pec(cpec, msg); |
2443 | |
2444 | if (rpec != cpec) { |
2445 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", |
2446 | rpec, cpec); |
2447 | return -EBADMSG; |
2448 | } |
2449 | return 0; |
2450 | } |
2451 | |
2452 | /** |
2453 | * i2c_smbus_read_byte - SMBus "receive byte" protocol |
2454 | * @client: Handle to slave device |
2455 | * |
2456 | * This executes the SMBus "receive byte" protocol, returning negative errno |
2457 | * else the byte received from the device. |
2458 | */ |
2459 | s32 i2c_smbus_read_byte(const struct i2c_client *client) |
2460 | { |
2461 | union i2c_smbus_data data; |
2462 | int status; |
2463 | |
2464 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2465 | I2C_SMBUS_READ, 0, |
2466 | I2C_SMBUS_BYTE, &data); |
2467 | return (status < 0) ? status : data.byte; |
2468 | } |
2469 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
2470 | |
2471 | /** |
2472 | * i2c_smbus_write_byte - SMBus "send byte" protocol |
2473 | * @client: Handle to slave device |
2474 | * @value: Byte to be sent |
2475 | * |
2476 | * This executes the SMBus "send byte" protocol, returning negative errno |
2477 | * else zero on success. |
2478 | */ |
2479 | s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value) |
2480 | { |
2481 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2482 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
2483 | } |
2484 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
2485 | |
2486 | /** |
2487 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol |
2488 | * @client: Handle to slave device |
2489 | * @command: Byte interpreted by slave |
2490 | * |
2491 | * This executes the SMBus "read byte" protocol, returning negative errno |
2492 | * else a data byte received from the device. |
2493 | */ |
2494 | s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command) |
2495 | { |
2496 | union i2c_smbus_data data; |
2497 | int status; |
2498 | |
2499 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2500 | I2C_SMBUS_READ, command, |
2501 | I2C_SMBUS_BYTE_DATA, &data); |
2502 | return (status < 0) ? status : data.byte; |
2503 | } |
2504 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
2505 | |
2506 | /** |
2507 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol |
2508 | * @client: Handle to slave device |
2509 | * @command: Byte interpreted by slave |
2510 | * @value: Byte being written |
2511 | * |
2512 | * This executes the SMBus "write byte" protocol, returning negative errno |
2513 | * else zero on success. |
2514 | */ |
2515 | s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command, |
2516 | u8 value) |
2517 | { |
2518 | union i2c_smbus_data data; |
2519 | data.byte = value; |
2520 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2521 | I2C_SMBUS_WRITE, command, |
2522 | I2C_SMBUS_BYTE_DATA, &data); |
2523 | } |
2524 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
2525 | |
2526 | /** |
2527 | * i2c_smbus_read_word_data - SMBus "read word" protocol |
2528 | * @client: Handle to slave device |
2529 | * @command: Byte interpreted by slave |
2530 | * |
2531 | * This executes the SMBus "read word" protocol, returning negative errno |
2532 | * else a 16-bit unsigned "word" received from the device. |
2533 | */ |
2534 | s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command) |
2535 | { |
2536 | union i2c_smbus_data data; |
2537 | int status; |
2538 | |
2539 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2540 | I2C_SMBUS_READ, command, |
2541 | I2C_SMBUS_WORD_DATA, &data); |
2542 | return (status < 0) ? status : data.word; |
2543 | } |
2544 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
2545 | |
2546 | /** |
2547 | * i2c_smbus_write_word_data - SMBus "write word" protocol |
2548 | * @client: Handle to slave device |
2549 | * @command: Byte interpreted by slave |
2550 | * @value: 16-bit "word" being written |
2551 | * |
2552 | * This executes the SMBus "write word" protocol, returning negative errno |
2553 | * else zero on success. |
2554 | */ |
2555 | s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command, |
2556 | u16 value) |
2557 | { |
2558 | union i2c_smbus_data data; |
2559 | data.word = value; |
2560 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2561 | I2C_SMBUS_WRITE, command, |
2562 | I2C_SMBUS_WORD_DATA, &data); |
2563 | } |
2564 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
2565 | |
2566 | /** |
2567 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
2568 | * @client: Handle to slave device |
2569 | * @command: Byte interpreted by slave |
2570 | * @values: Byte array into which data will be read; big enough to hold |
2571 | * the data returned by the slave. SMBus allows at most 32 bytes. |
2572 | * |
2573 | * This executes the SMBus "block read" protocol, returning negative errno |
2574 | * else the number of data bytes in the slave's response. |
2575 | * |
2576 | * Note that using this function requires that the client's adapter support |
2577 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers |
2578 | * support this; its emulation through I2C messaging relies on a specific |
2579 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. |
2580 | */ |
2581 | s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command, |
2582 | u8 *values) |
2583 | { |
2584 | union i2c_smbus_data data; |
2585 | int status; |
2586 | |
2587 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2588 | I2C_SMBUS_READ, command, |
2589 | I2C_SMBUS_BLOCK_DATA, &data); |
2590 | if (status) |
2591 | return status; |
2592 | |
2593 | memcpy(values, &data.block[1], data.block[0]); |
2594 | return data.block[0]; |
2595 | } |
2596 | EXPORT_SYMBOL(i2c_smbus_read_block_data); |
2597 | |
2598 | /** |
2599 | * i2c_smbus_write_block_data - SMBus "block write" protocol |
2600 | * @client: Handle to slave device |
2601 | * @command: Byte interpreted by slave |
2602 | * @length: Size of data block; SMBus allows at most 32 bytes |
2603 | * @values: Byte array which will be written. |
2604 | * |
2605 | * This executes the SMBus "block write" protocol, returning negative errno |
2606 | * else zero on success. |
2607 | */ |
2608 | s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command, |
2609 | u8 length, const u8 *values) |
2610 | { |
2611 | union i2c_smbus_data data; |
2612 | |
2613 | if (length > I2C_SMBUS_BLOCK_MAX) |
2614 | length = I2C_SMBUS_BLOCK_MAX; |
2615 | data.block[0] = length; |
2616 | memcpy(&data.block[1], values, length); |
2617 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2618 | I2C_SMBUS_WRITE, command, |
2619 | I2C_SMBUS_BLOCK_DATA, &data); |
2620 | } |
2621 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
2622 | |
2623 | /* Returns the number of read bytes */ |
2624 | s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command, |
2625 | u8 length, u8 *values) |
2626 | { |
2627 | union i2c_smbus_data data; |
2628 | int status; |
2629 | |
2630 | if (length > I2C_SMBUS_BLOCK_MAX) |
2631 | length = I2C_SMBUS_BLOCK_MAX; |
2632 | data.block[0] = length; |
2633 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2634 | I2C_SMBUS_READ, command, |
2635 | I2C_SMBUS_I2C_BLOCK_DATA, &data); |
2636 | if (status < 0) |
2637 | return status; |
2638 | |
2639 | memcpy(values, &data.block[1], data.block[0]); |
2640 | return data.block[0]; |
2641 | } |
2642 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
2643 | |
2644 | s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command, |
2645 | u8 length, const u8 *values) |
2646 | { |
2647 | union i2c_smbus_data data; |
2648 | |
2649 | if (length > I2C_SMBUS_BLOCK_MAX) |
2650 | length = I2C_SMBUS_BLOCK_MAX; |
2651 | data.block[0] = length; |
2652 | memcpy(data.block + 1, values, length); |
2653 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
2654 | I2C_SMBUS_WRITE, command, |
2655 | I2C_SMBUS_I2C_BLOCK_DATA, &data); |
2656 | } |
2657 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
2658 | |
2659 | /* Simulate a SMBus command using the i2c protocol |
2660 | No checking of parameters is done! */ |
2661 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, |
2662 | unsigned short flags, |
2663 | char read_write, u8 command, int size, |
2664 | union i2c_smbus_data *data) |
2665 | { |
2666 | /* So we need to generate a series of msgs. In the case of writing, we |
2667 | need to use only one message; when reading, we need two. We initialize |
2668 | most things with sane defaults, to keep the code below somewhat |
2669 | simpler. */ |
2670 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
2671 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; |
2672 | int num = read_write == I2C_SMBUS_READ ? 2 : 1; |
2673 | int i; |
2674 | u8 partial_pec = 0; |
2675 | int status; |
2676 | struct i2c_msg msg[2] = { |
2677 | { |
2678 | .addr = addr, |
2679 | .flags = flags, |
2680 | .len = 1, |
2681 | .buf = msgbuf0, |
2682 | }, { |
2683 | .addr = addr, |
2684 | .flags = flags | I2C_M_RD, |
2685 | .len = 0, |
2686 | .buf = msgbuf1, |
2687 | }, |
2688 | }; |
2689 | |
2690 | msgbuf0[0] = command; |
2691 | switch (size) { |
2692 | case I2C_SMBUS_QUICK: |
2693 | msg[0].len = 0; |
2694 | /* Special case: The read/write field is used as data */ |
2695 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
2696 | I2C_M_RD : 0); |
2697 | num = 1; |
2698 | break; |
2699 | case I2C_SMBUS_BYTE: |
2700 | if (read_write == I2C_SMBUS_READ) { |
2701 | /* Special case: only a read! */ |
2702 | msg[0].flags = I2C_M_RD | flags; |
2703 | num = 1; |
2704 | } |
2705 | break; |
2706 | case I2C_SMBUS_BYTE_DATA: |
2707 | if (read_write == I2C_SMBUS_READ) |
2708 | msg[1].len = 1; |
2709 | else { |
2710 | msg[0].len = 2; |
2711 | msgbuf0[1] = data->byte; |
2712 | } |
2713 | break; |
2714 | case I2C_SMBUS_WORD_DATA: |
2715 | if (read_write == I2C_SMBUS_READ) |
2716 | msg[1].len = 2; |
2717 | else { |
2718 | msg[0].len = 3; |
2719 | msgbuf0[1] = data->word & 0xff; |
2720 | msgbuf0[2] = data->word >> 8; |
2721 | } |
2722 | break; |
2723 | case I2C_SMBUS_PROC_CALL: |
2724 | num = 2; /* Special case */ |
2725 | read_write = I2C_SMBUS_READ; |
2726 | msg[0].len = 3; |
2727 | msg[1].len = 2; |
2728 | msgbuf0[1] = data->word & 0xff; |
2729 | msgbuf0[2] = data->word >> 8; |
2730 | break; |
2731 | case I2C_SMBUS_BLOCK_DATA: |
2732 | if (read_write == I2C_SMBUS_READ) { |
2733 | msg[1].flags |= I2C_M_RECV_LEN; |
2734 | msg[1].len = 1; /* block length will be added by |
2735 | the underlying bus driver */ |
2736 | } else { |
2737 | msg[0].len = data->block[0] + 2; |
2738 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { |
2739 | dev_err(&adapter->dev, |
2740 | "Invalid block write size %d\n", |
2741 | data->block[0]); |
2742 | return -EINVAL; |
2743 | } |
2744 | for (i = 1; i < msg[0].len; i++) |
2745 | msgbuf0[i] = data->block[i-1]; |
2746 | } |
2747 | break; |
2748 | case I2C_SMBUS_BLOCK_PROC_CALL: |
2749 | num = 2; /* Another special case */ |
2750 | read_write = I2C_SMBUS_READ; |
2751 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { |
2752 | dev_err(&adapter->dev, |
2753 | "Invalid block write size %d\n", |
2754 | data->block[0]); |
2755 | return -EINVAL; |
2756 | } |
2757 | msg[0].len = data->block[0] + 2; |
2758 | for (i = 1; i < msg[0].len; i++) |
2759 | msgbuf0[i] = data->block[i-1]; |
2760 | msg[1].flags |= I2C_M_RECV_LEN; |
2761 | msg[1].len = 1; /* block length will be added by |
2762 | the underlying bus driver */ |
2763 | break; |
2764 | case I2C_SMBUS_I2C_BLOCK_DATA: |
2765 | if (read_write == I2C_SMBUS_READ) { |
2766 | msg[1].len = data->block[0]; |
2767 | } else { |
2768 | msg[0].len = data->block[0] + 1; |
2769 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
2770 | dev_err(&adapter->dev, |
2771 | "Invalid block write size %d\n", |
2772 | data->block[0]); |
2773 | return -EINVAL; |
2774 | } |
2775 | for (i = 1; i <= data->block[0]; i++) |
2776 | msgbuf0[i] = data->block[i]; |
2777 | } |
2778 | break; |
2779 | default: |
2780 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
2781 | return -EOPNOTSUPP; |
2782 | } |
2783 | |
2784 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
2785 | && size != I2C_SMBUS_I2C_BLOCK_DATA); |
2786 | if (i) { |
2787 | /* Compute PEC if first message is a write */ |
2788 | if (!(msg[0].flags & I2C_M_RD)) { |
2789 | if (num == 1) /* Write only */ |
2790 | i2c_smbus_add_pec(&msg[0]); |
2791 | else /* Write followed by read */ |
2792 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); |
2793 | } |
2794 | /* Ask for PEC if last message is a read */ |
2795 | if (msg[num-1].flags & I2C_M_RD) |
2796 | msg[num-1].len++; |
2797 | } |
2798 | |
2799 | status = i2c_transfer(adapter, msg, num); |
2800 | if (status < 0) |
2801 | return status; |
2802 | |
2803 | /* Check PEC if last message is a read */ |
2804 | if (i && (msg[num-1].flags & I2C_M_RD)) { |
2805 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
2806 | if (status < 0) |
2807 | return status; |
2808 | } |
2809 | |
2810 | if (read_write == I2C_SMBUS_READ) |
2811 | switch (size) { |
2812 | case I2C_SMBUS_BYTE: |
2813 | data->byte = msgbuf0[0]; |
2814 | break; |
2815 | case I2C_SMBUS_BYTE_DATA: |
2816 | data->byte = msgbuf1[0]; |
2817 | break; |
2818 | case I2C_SMBUS_WORD_DATA: |
2819 | case I2C_SMBUS_PROC_CALL: |
2820 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); |
2821 | break; |
2822 | case I2C_SMBUS_I2C_BLOCK_DATA: |
2823 | for (i = 0; i < data->block[0]; i++) |
2824 | data->block[i+1] = msgbuf1[i]; |
2825 | break; |
2826 | case I2C_SMBUS_BLOCK_DATA: |
2827 | case I2C_SMBUS_BLOCK_PROC_CALL: |
2828 | for (i = 0; i < msgbuf1[0] + 1; i++) |
2829 | data->block[i] = msgbuf1[i]; |
2830 | break; |
2831 | } |
2832 | return 0; |
2833 | } |
2834 | |
2835 | /** |
2836 | * i2c_smbus_xfer - execute SMBus protocol operations |
2837 | * @adapter: Handle to I2C bus |
2838 | * @addr: Address of SMBus slave on that bus |
2839 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) |
2840 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE |
2841 | * @command: Byte interpreted by slave, for protocols which use such bytes |
2842 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL |
2843 | * @data: Data to be read or written |
2844 | * |
2845 | * This executes an SMBus protocol operation, and returns a negative |
2846 | * errno code else zero on success. |
2847 | */ |
2848 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
2849 | char read_write, u8 command, int protocol, |
2850 | union i2c_smbus_data *data) |
2851 | { |
2852 | unsigned long orig_jiffies; |
2853 | int try; |
2854 | s32 res; |
2855 | |
2856 | /* If enabled, the following two tracepoints are conditional on |
2857 | * read_write and protocol. |
2858 | */ |
2859 | trace_smbus_write(adapter, addr, flags, read_write, |
2860 | command, protocol, data); |
2861 | trace_smbus_read(adapter, addr, flags, read_write, |
2862 | command, protocol); |
2863 | |
2864 | flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB; |
2865 | |
2866 | if (adapter->algo->smbus_xfer) { |
2867 | i2c_lock_adapter(adapter); |
2868 | |
2869 | /* Retry automatically on arbitration loss */ |
2870 | orig_jiffies = jiffies; |
2871 | for (res = 0, try = 0; try <= adapter->retries; try++) { |
2872 | res = adapter->algo->smbus_xfer(adapter, addr, flags, |
2873 | read_write, command, |
2874 | protocol, data); |
2875 | if (res != -EAGAIN) |
2876 | break; |
2877 | if (time_after(jiffies, |
2878 | orig_jiffies + adapter->timeout)) |
2879 | break; |
2880 | } |
2881 | i2c_unlock_adapter(adapter); |
2882 | |
2883 | if (res != -EOPNOTSUPP || !adapter->algo->master_xfer) |
2884 | goto trace; |
2885 | /* |
2886 | * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't |
2887 | * implement native support for the SMBus operation. |
2888 | */ |
2889 | } |
2890 | |
2891 | res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, |
2892 | command, protocol, data); |
2893 | |
2894 | trace: |
2895 | /* If enabled, the reply tracepoint is conditional on read_write. */ |
2896 | trace_smbus_reply(adapter, addr, flags, read_write, |
2897 | command, protocol, data); |
2898 | trace_smbus_result(adapter, addr, flags, read_write, |
2899 | command, protocol, res); |
2900 | |
2901 | return res; |
2902 | } |
2903 | EXPORT_SYMBOL(i2c_smbus_xfer); |
2904 | |
2905 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); |
2906 | MODULE_DESCRIPTION("I2C-Bus main module"); |
2907 | MODULE_LICENSE("GPL"); |
2908 |
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v2.6.34-rc5
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