This source file includes following definitions.
- i2c_acpi_get_i2c_resource
- i2c_acpi_fill_info
- i2c_acpi_do_lookup
- i2c_acpi_add_resource
- i2c_acpi_get_irq
- i2c_acpi_get_info
- i2c_acpi_register_device
- i2c_acpi_add_device
- i2c_acpi_register_devices
- i2c_acpi_match_device
- i2c_acpi_lookup_speed
- i2c_acpi_find_bus_speed
- i2c_acpi_find_match_adapter
- i2c_acpi_find_adapter_by_handle
- i2c_acpi_find_client_by_adev
- i2c_acpi_notify
- i2c_acpi_new_device
- acpi_gsb_i2c_read_bytes
- acpi_gsb_i2c_write_bytes
- i2c_acpi_space_handler
- i2c_acpi_install_space_handler
- i2c_acpi_remove_space_handler
1
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6
7
8 #include <linux/acpi.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/i2c.h>
12 #include <linux/list.h>
13 #include <linux/module.h>
14 #include <linux/slab.h>
15
16 #include "i2c-core.h"
17
18 struct i2c_acpi_handler_data {
19 struct acpi_connection_info info;
20 struct i2c_adapter *adapter;
21 };
22
23 struct gsb_buffer {
24 u8 status;
25 u8 len;
26 union {
27 u16 wdata;
28 u8 bdata;
29 u8 data[0];
30 };
31 } __packed;
32
33 struct i2c_acpi_lookup {
34 struct i2c_board_info *info;
35 acpi_handle adapter_handle;
36 acpi_handle device_handle;
37 acpi_handle search_handle;
38 int n;
39 int index;
40 u32 speed;
41 u32 min_speed;
42 u32 force_speed;
43 };
44
45
46
47
48
49
50
51
52
53
54
55 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
56 struct acpi_resource_i2c_serialbus **i2c)
57 {
58 struct acpi_resource_i2c_serialbus *sb;
59
60 if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
61 return false;
62
63 sb = &ares->data.i2c_serial_bus;
64 if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
65 return false;
66
67 *i2c = sb;
68 return true;
69 }
70 EXPORT_SYMBOL_GPL(i2c_acpi_get_i2c_resource);
71
72 static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
73 {
74 struct i2c_acpi_lookup *lookup = data;
75 struct i2c_board_info *info = lookup->info;
76 struct acpi_resource_i2c_serialbus *sb;
77 acpi_status status;
78
79 if (info->addr || !i2c_acpi_get_i2c_resource(ares, &sb))
80 return 1;
81
82 if (lookup->index != -1 && lookup->n++ != lookup->index)
83 return 1;
84
85 status = acpi_get_handle(lookup->device_handle,
86 sb->resource_source.string_ptr,
87 &lookup->adapter_handle);
88 if (ACPI_FAILURE(status))
89 return 1;
90
91 info->addr = sb->slave_address;
92 lookup->speed = sb->connection_speed;
93 if (sb->access_mode == ACPI_I2C_10BIT_MODE)
94 info->flags |= I2C_CLIENT_TEN;
95
96 return 1;
97 }
98
99 static const struct acpi_device_id i2c_acpi_ignored_device_ids[] = {
100
101
102
103
104 { ACPI_VIDEO_HID, 0 },
105 {}
106 };
107
108 static int i2c_acpi_do_lookup(struct acpi_device *adev,
109 struct i2c_acpi_lookup *lookup)
110 {
111 struct i2c_board_info *info = lookup->info;
112 struct list_head resource_list;
113 int ret;
114
115 if (acpi_bus_get_status(adev) || !adev->status.present)
116 return -EINVAL;
117
118 if (acpi_match_device_ids(adev, i2c_acpi_ignored_device_ids) == 0)
119 return -ENODEV;
120
121 memset(info, 0, sizeof(*info));
122 lookup->device_handle = acpi_device_handle(adev);
123
124
125 INIT_LIST_HEAD(&resource_list);
126 ret = acpi_dev_get_resources(adev, &resource_list,
127 i2c_acpi_fill_info, lookup);
128 acpi_dev_free_resource_list(&resource_list);
129
130 if (ret < 0 || !info->addr)
131 return -EINVAL;
132
133 return 0;
134 }
135
136 static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
137 {
138 int *irq = data;
139 struct resource r;
140
141 if (*irq <= 0 && acpi_dev_resource_interrupt(ares, 0, &r))
142 *irq = i2c_dev_irq_from_resources(&r, 1);
143
144 return 1;
145 }
146
147
148
149
150
151
152
153
154
155 int i2c_acpi_get_irq(struct i2c_client *client)
156 {
157 struct acpi_device *adev = ACPI_COMPANION(&client->dev);
158 struct list_head resource_list;
159 int irq = -ENOENT;
160 int ret;
161
162 INIT_LIST_HEAD(&resource_list);
163
164 ret = acpi_dev_get_resources(adev, &resource_list,
165 i2c_acpi_add_resource, &irq);
166 if (ret < 0)
167 return ret;
168
169 acpi_dev_free_resource_list(&resource_list);
170
171 if (irq == -ENOENT)
172 irq = acpi_dev_gpio_irq_get(adev, 0);
173
174 return irq;
175 }
176
177 static int i2c_acpi_get_info(struct acpi_device *adev,
178 struct i2c_board_info *info,
179 struct i2c_adapter *adapter,
180 acpi_handle *adapter_handle)
181 {
182 struct i2c_acpi_lookup lookup;
183 int ret;
184
185 memset(&lookup, 0, sizeof(lookup));
186 lookup.info = info;
187 lookup.index = -1;
188
189 if (acpi_device_enumerated(adev))
190 return -EINVAL;
191
192 ret = i2c_acpi_do_lookup(adev, &lookup);
193 if (ret)
194 return ret;
195
196 if (adapter) {
197
198 if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
199 return -ENODEV;
200 } else {
201 struct acpi_device *adapter_adev;
202
203
204 if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev))
205 return -ENODEV;
206 if (acpi_bus_get_status(adapter_adev) ||
207 !adapter_adev->status.present)
208 return -ENODEV;
209 }
210
211 info->fwnode = acpi_fwnode_handle(adev);
212 if (adapter_handle)
213 *adapter_handle = lookup.adapter_handle;
214
215 acpi_set_modalias(adev, dev_name(&adev->dev), info->type,
216 sizeof(info->type));
217
218 return 0;
219 }
220
221 static void i2c_acpi_register_device(struct i2c_adapter *adapter,
222 struct acpi_device *adev,
223 struct i2c_board_info *info)
224 {
225 adev->power.flags.ignore_parent = true;
226 acpi_device_set_enumerated(adev);
227
228 if (!i2c_new_device(adapter, info)) {
229 adev->power.flags.ignore_parent = false;
230 dev_err(&adapter->dev,
231 "failed to add I2C device %s from ACPI\n",
232 dev_name(&adev->dev));
233 }
234 }
235
236 static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
237 void *data, void **return_value)
238 {
239 struct i2c_adapter *adapter = data;
240 struct acpi_device *adev;
241 struct i2c_board_info info;
242
243 if (acpi_bus_get_device(handle, &adev))
244 return AE_OK;
245
246 if (i2c_acpi_get_info(adev, &info, adapter, NULL))
247 return AE_OK;
248
249 i2c_acpi_register_device(adapter, adev, &info);
250
251 return AE_OK;
252 }
253
254 #define I2C_ACPI_MAX_SCAN_DEPTH 32
255
256
257
258
259
260
261
262
263
264 void i2c_acpi_register_devices(struct i2c_adapter *adap)
265 {
266 acpi_status status;
267
268 if (!has_acpi_companion(&adap->dev))
269 return;
270
271 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
272 I2C_ACPI_MAX_SCAN_DEPTH,
273 i2c_acpi_add_device, NULL,
274 adap, NULL);
275 if (ACPI_FAILURE(status))
276 dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
277 }
278
279 const struct acpi_device_id *
280 i2c_acpi_match_device(const struct acpi_device_id *matches,
281 struct i2c_client *client)
282 {
283 if (!(client && matches))
284 return NULL;
285
286 return acpi_match_device(matches, &client->dev);
287 }
288
289 static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
290
291
292
293
294
295
296
297
298 { "MSSL1680", 0 },
299 {}
300 };
301
302 static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
303 void *data, void **return_value)
304 {
305 struct i2c_acpi_lookup *lookup = data;
306 struct acpi_device *adev;
307
308 if (acpi_bus_get_device(handle, &adev))
309 return AE_OK;
310
311 if (i2c_acpi_do_lookup(adev, lookup))
312 return AE_OK;
313
314 if (lookup->search_handle != lookup->adapter_handle)
315 return AE_OK;
316
317 if (lookup->speed <= lookup->min_speed)
318 lookup->min_speed = lookup->speed;
319
320 if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)
321 lookup->force_speed = 400000;
322
323 return AE_OK;
324 }
325
326
327
328
329
330
331
332
333
334
335 u32 i2c_acpi_find_bus_speed(struct device *dev)
336 {
337 struct i2c_acpi_lookup lookup;
338 struct i2c_board_info dummy;
339 acpi_status status;
340
341 if (!has_acpi_companion(dev))
342 return 0;
343
344 memset(&lookup, 0, sizeof(lookup));
345 lookup.search_handle = ACPI_HANDLE(dev);
346 lookup.min_speed = UINT_MAX;
347 lookup.info = &dummy;
348 lookup.index = -1;
349
350 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
351 I2C_ACPI_MAX_SCAN_DEPTH,
352 i2c_acpi_lookup_speed, NULL,
353 &lookup, NULL);
354
355 if (ACPI_FAILURE(status)) {
356 dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
357 return 0;
358 }
359
360 if (lookup.force_speed) {
361 if (lookup.force_speed != lookup.min_speed)
362 dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n",
363 lookup.min_speed, lookup.force_speed);
364 return lookup.force_speed;
365 } else if (lookup.min_speed != UINT_MAX) {
366 return lookup.min_speed;
367 } else {
368 return 0;
369 }
370 }
371 EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
372
373 static int i2c_acpi_find_match_adapter(struct device *dev, const void *data)
374 {
375 struct i2c_adapter *adapter = i2c_verify_adapter(dev);
376
377 if (!adapter)
378 return 0;
379
380 return ACPI_HANDLE(dev) == (acpi_handle)data;
381 }
382
383 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
384 {
385 struct device *dev;
386
387 dev = bus_find_device(&i2c_bus_type, NULL, handle,
388 i2c_acpi_find_match_adapter);
389
390 return dev ? i2c_verify_adapter(dev) : NULL;
391 }
392 EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
393
394 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
395 {
396 struct device *dev;
397 struct i2c_client *client;
398
399 dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev);
400 if (!dev)
401 return NULL;
402
403 client = i2c_verify_client(dev);
404 if (!client)
405 put_device(dev);
406
407 return client;
408 }
409
410 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
411 void *arg)
412 {
413 struct acpi_device *adev = arg;
414 struct i2c_board_info info;
415 acpi_handle adapter_handle;
416 struct i2c_adapter *adapter;
417 struct i2c_client *client;
418
419 switch (value) {
420 case ACPI_RECONFIG_DEVICE_ADD:
421 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
422 break;
423
424 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
425 if (!adapter)
426 break;
427
428 i2c_acpi_register_device(adapter, adev, &info);
429 break;
430 case ACPI_RECONFIG_DEVICE_REMOVE:
431 if (!acpi_device_enumerated(adev))
432 break;
433
434 client = i2c_acpi_find_client_by_adev(adev);
435 if (!client)
436 break;
437
438 i2c_unregister_device(client);
439 put_device(&client->dev);
440 break;
441 }
442
443 return NOTIFY_OK;
444 }
445
446 struct notifier_block i2c_acpi_notifier = {
447 .notifier_call = i2c_acpi_notify,
448 };
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
468 struct i2c_board_info *info)
469 {
470 struct i2c_acpi_lookup lookup;
471 struct i2c_adapter *adapter;
472 struct i2c_client *client;
473 struct acpi_device *adev;
474 LIST_HEAD(resource_list);
475 int ret;
476
477 adev = ACPI_COMPANION(dev);
478 if (!adev)
479 return ERR_PTR(-EINVAL);
480
481 memset(&lookup, 0, sizeof(lookup));
482 lookup.info = info;
483 lookup.device_handle = acpi_device_handle(adev);
484 lookup.index = index;
485
486 ret = acpi_dev_get_resources(adev, &resource_list,
487 i2c_acpi_fill_info, &lookup);
488 if (ret < 0)
489 return ERR_PTR(ret);
490
491 acpi_dev_free_resource_list(&resource_list);
492
493 if (!info->addr)
494 return ERR_PTR(-EADDRNOTAVAIL);
495
496 adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
497 if (!adapter)
498 return ERR_PTR(-EPROBE_DEFER);
499
500 client = i2c_new_device(adapter, info);
501 if (!client)
502 return ERR_PTR(-ENODEV);
503
504 return client;
505 }
506 EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
507
508 #ifdef CONFIG_ACPI_I2C_OPREGION
509 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
510 u8 cmd, u8 *data, u8 data_len)
511 {
512
513 struct i2c_msg msgs[2];
514 int ret;
515 u8 *buffer;
516
517 buffer = kzalloc(data_len, GFP_KERNEL);
518 if (!buffer)
519 return AE_NO_MEMORY;
520
521 msgs[0].addr = client->addr;
522 msgs[0].flags = client->flags;
523 msgs[0].len = 1;
524 msgs[0].buf = &cmd;
525
526 msgs[1].addr = client->addr;
527 msgs[1].flags = client->flags | I2C_M_RD;
528 msgs[1].len = data_len;
529 msgs[1].buf = buffer;
530
531 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
532 if (ret < 0) {
533
534 if (ret == -EREMOTEIO)
535 dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
536 data_len, client->addr, cmd, ret);
537 else
538 dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
539 data_len, client->addr, cmd, ret);
540
541 } else if (ret == 2) {
542 memcpy(data, buffer, data_len);
543 ret = 0;
544 } else {
545 ret = -EIO;
546 }
547
548 kfree(buffer);
549 return ret;
550 }
551
552 static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
553 u8 cmd, u8 *data, u8 data_len)
554 {
555
556 struct i2c_msg msgs[1];
557 u8 *buffer;
558 int ret = AE_OK;
559
560 buffer = kzalloc(data_len + 1, GFP_KERNEL);
561 if (!buffer)
562 return AE_NO_MEMORY;
563
564 buffer[0] = cmd;
565 memcpy(buffer + 1, data, data_len);
566
567 msgs[0].addr = client->addr;
568 msgs[0].flags = client->flags;
569 msgs[0].len = data_len + 1;
570 msgs[0].buf = buffer;
571
572 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
573
574 kfree(buffer);
575
576 if (ret < 0) {
577 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
578 return ret;
579 }
580
581
582 return (ret == 1) ? 0 : -EIO;
583 }
584
585 static acpi_status
586 i2c_acpi_space_handler(u32 function, acpi_physical_address command,
587 u32 bits, u64 *value64,
588 void *handler_context, void *region_context)
589 {
590 struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
591 struct i2c_acpi_handler_data *data = handler_context;
592 struct acpi_connection_info *info = &data->info;
593 struct acpi_resource_i2c_serialbus *sb;
594 struct i2c_adapter *adapter = data->adapter;
595 struct i2c_client *client;
596 struct acpi_resource *ares;
597 u32 accessor_type = function >> 16;
598 u8 action = function & ACPI_IO_MASK;
599 acpi_status ret;
600 int status;
601
602 ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
603 if (ACPI_FAILURE(ret))
604 return ret;
605
606 client = kzalloc(sizeof(*client), GFP_KERNEL);
607 if (!client) {
608 ret = AE_NO_MEMORY;
609 goto err;
610 }
611
612 if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
613 ret = AE_BAD_PARAMETER;
614 goto err;
615 }
616
617 client->adapter = adapter;
618 client->addr = sb->slave_address;
619
620 if (sb->access_mode == ACPI_I2C_10BIT_MODE)
621 client->flags |= I2C_CLIENT_TEN;
622
623 switch (accessor_type) {
624 case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
625 if (action == ACPI_READ) {
626 status = i2c_smbus_read_byte(client);
627 if (status >= 0) {
628 gsb->bdata = status;
629 status = 0;
630 }
631 } else {
632 status = i2c_smbus_write_byte(client, gsb->bdata);
633 }
634 break;
635
636 case ACPI_GSB_ACCESS_ATTRIB_BYTE:
637 if (action == ACPI_READ) {
638 status = i2c_smbus_read_byte_data(client, command);
639 if (status >= 0) {
640 gsb->bdata = status;
641 status = 0;
642 }
643 } else {
644 status = i2c_smbus_write_byte_data(client, command,
645 gsb->bdata);
646 }
647 break;
648
649 case ACPI_GSB_ACCESS_ATTRIB_WORD:
650 if (action == ACPI_READ) {
651 status = i2c_smbus_read_word_data(client, command);
652 if (status >= 0) {
653 gsb->wdata = status;
654 status = 0;
655 }
656 } else {
657 status = i2c_smbus_write_word_data(client, command,
658 gsb->wdata);
659 }
660 break;
661
662 case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
663 if (action == ACPI_READ) {
664 status = i2c_smbus_read_block_data(client, command,
665 gsb->data);
666 if (status >= 0) {
667 gsb->len = status;
668 status = 0;
669 }
670 } else {
671 status = i2c_smbus_write_block_data(client, command,
672 gsb->len, gsb->data);
673 }
674 break;
675
676 case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
677 if (action == ACPI_READ) {
678 status = acpi_gsb_i2c_read_bytes(client, command,
679 gsb->data, info->access_length);
680 } else {
681 status = acpi_gsb_i2c_write_bytes(client, command,
682 gsb->data, info->access_length);
683 }
684 break;
685
686 default:
687 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
688 accessor_type, client->addr);
689 ret = AE_BAD_PARAMETER;
690 goto err;
691 }
692
693 gsb->status = status;
694
695 err:
696 kfree(client);
697 ACPI_FREE(ares);
698 return ret;
699 }
700
701
702 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
703 {
704 acpi_handle handle;
705 struct i2c_acpi_handler_data *data;
706 acpi_status status;
707
708 if (!adapter->dev.parent)
709 return -ENODEV;
710
711 handle = ACPI_HANDLE(adapter->dev.parent);
712
713 if (!handle)
714 return -ENODEV;
715
716 data = kzalloc(sizeof(struct i2c_acpi_handler_data),
717 GFP_KERNEL);
718 if (!data)
719 return -ENOMEM;
720
721 data->adapter = adapter;
722 status = acpi_bus_attach_private_data(handle, (void *)data);
723 if (ACPI_FAILURE(status)) {
724 kfree(data);
725 return -ENOMEM;
726 }
727
728 status = acpi_install_address_space_handler(handle,
729 ACPI_ADR_SPACE_GSBUS,
730 &i2c_acpi_space_handler,
731 NULL,
732 data);
733 if (ACPI_FAILURE(status)) {
734 dev_err(&adapter->dev, "Error installing i2c space handler\n");
735 acpi_bus_detach_private_data(handle);
736 kfree(data);
737 return -ENOMEM;
738 }
739
740 acpi_walk_dep_device_list(handle);
741 return 0;
742 }
743
744 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
745 {
746 acpi_handle handle;
747 struct i2c_acpi_handler_data *data;
748 acpi_status status;
749
750 if (!adapter->dev.parent)
751 return;
752
753 handle = ACPI_HANDLE(adapter->dev.parent);
754
755 if (!handle)
756 return;
757
758 acpi_remove_address_space_handler(handle,
759 ACPI_ADR_SPACE_GSBUS,
760 &i2c_acpi_space_handler);
761
762 status = acpi_bus_get_private_data(handle, (void **)&data);
763 if (ACPI_SUCCESS(status))
764 kfree(data);
765
766 acpi_bus_detach_private_data(handle);
767 }
768 #endif