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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
18struct i2c_acpi_handler_data {
19 struct acpi_connection_info info;
20 struct i2c_adapter *adapter;
21};
22
23struct gsb_buffer {
24 u8 status;
25 u8 len;
26 union {
27 u16 wdata;
28 u8 bdata;
29 u8 data[0];
30 };
31} __packed;
32
33struct 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
55bool 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}
70EXPORT_SYMBOL_GPL(i2c_acpi_get_i2c_resource);
71
72static 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
99static const struct acpi_device_id i2c_acpi_ignored_device_ids[] = {
100
101
102
103
104 { ACPI_VIDEO_HID, 0 },
105 {}
106};
107
108static 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
136static 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
155int 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
177static 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
221static 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 (IS_ERR(i2c_new_client_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
236static 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
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260
261
262
263
264void i2c_acpi_register_devices(struct i2c_adapter *adap)
265{
266 struct acpi_device *adev;
267 acpi_status status;
268
269 if (!has_acpi_companion(&adap->dev))
270 return;
271
272 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
273 I2C_ACPI_MAX_SCAN_DEPTH,
274 i2c_acpi_add_device, NULL,
275 adap, NULL);
276 if (ACPI_FAILURE(status))
277 dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
278
279 if (!adap->dev.parent)
280 return;
281
282 adev = ACPI_COMPANION(adap->dev.parent);
283 if (!adev)
284 return;
285
286 acpi_dev_clear_dependencies(adev);
287}
288
289const struct acpi_device_id *
290i2c_acpi_match_device(const struct acpi_device_id *matches,
291 struct i2c_client *client)
292{
293 if (!(client && matches))
294 return NULL;
295
296 return acpi_match_device(matches, &client->dev);
297}
298
299static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
300
301
302
303
304
305
306
307
308 { "MSSL1680", 0 },
309 {}
310};
311
312static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
313 void *data, void **return_value)
314{
315 struct i2c_acpi_lookup *lookup = data;
316 struct acpi_device *adev;
317
318 if (acpi_bus_get_device(handle, &adev))
319 return AE_OK;
320
321 if (i2c_acpi_do_lookup(adev, lookup))
322 return AE_OK;
323
324 if (lookup->search_handle != lookup->adapter_handle)
325 return AE_OK;
326
327 if (lookup->speed <= lookup->min_speed)
328 lookup->min_speed = lookup->speed;
329
330 if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)
331 lookup->force_speed = I2C_MAX_FAST_MODE_FREQ;
332
333 return AE_OK;
334}
335
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339
340
341
342
343
344
345u32 i2c_acpi_find_bus_speed(struct device *dev)
346{
347 struct i2c_acpi_lookup lookup;
348 struct i2c_board_info dummy;
349 acpi_status status;
350
351 if (!has_acpi_companion(dev))
352 return 0;
353
354 memset(&lookup, 0, sizeof(lookup));
355 lookup.search_handle = ACPI_HANDLE(dev);
356 lookup.min_speed = UINT_MAX;
357 lookup.info = &dummy;
358 lookup.index = -1;
359
360 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
361 I2C_ACPI_MAX_SCAN_DEPTH,
362 i2c_acpi_lookup_speed, NULL,
363 &lookup, NULL);
364
365 if (ACPI_FAILURE(status)) {
366 dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
367 return 0;
368 }
369
370 if (lookup.force_speed) {
371 if (lookup.force_speed != lookup.min_speed)
372 dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n",
373 lookup.min_speed, lookup.force_speed);
374 return lookup.force_speed;
375 } else if (lookup.min_speed != UINT_MAX) {
376 return lookup.min_speed;
377 } else {
378 return 0;
379 }
380}
381EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
382
383static int i2c_acpi_find_match_adapter(struct device *dev, const void *data)
384{
385 struct i2c_adapter *adapter = i2c_verify_adapter(dev);
386
387 if (!adapter)
388 return 0;
389
390 return ACPI_HANDLE(dev) == (acpi_handle)data;
391}
392
393
394struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
395{
396 struct device *dev;
397
398 dev = bus_find_device(&i2c_bus_type, NULL, handle,
399 i2c_acpi_find_match_adapter);
400
401 return dev ? i2c_verify_adapter(dev) : NULL;
402}
403EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
404
405static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
406{
407 struct device *dev;
408 struct i2c_client *client;
409
410 dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev);
411 if (!dev)
412 return NULL;
413
414 client = i2c_verify_client(dev);
415 if (!client)
416 put_device(dev);
417
418 return client;
419}
420
421static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
422 void *arg)
423{
424 struct acpi_device *adev = arg;
425 struct i2c_board_info info;
426 acpi_handle adapter_handle;
427 struct i2c_adapter *adapter;
428 struct i2c_client *client;
429
430 switch (value) {
431 case ACPI_RECONFIG_DEVICE_ADD:
432 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
433 break;
434
435 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
436 if (!adapter)
437 break;
438
439 i2c_acpi_register_device(adapter, adev, &info);
440 break;
441 case ACPI_RECONFIG_DEVICE_REMOVE:
442 if (!acpi_device_enumerated(adev))
443 break;
444
445 client = i2c_acpi_find_client_by_adev(adev);
446 if (!client)
447 break;
448
449 i2c_unregister_device(client);
450 put_device(&client->dev);
451 break;
452 }
453
454 return NOTIFY_OK;
455}
456
457struct notifier_block i2c_acpi_notifier = {
458 .notifier_call = i2c_acpi_notify,
459};
460
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478
479struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
480 struct i2c_board_info *info)
481{
482 struct i2c_acpi_lookup lookup;
483 struct i2c_adapter *adapter;
484 struct acpi_device *adev;
485 LIST_HEAD(resource_list);
486 int ret;
487
488 adev = ACPI_COMPANION(dev);
489 if (!adev)
490 return ERR_PTR(-EINVAL);
491
492 memset(&lookup, 0, sizeof(lookup));
493 lookup.info = info;
494 lookup.device_handle = acpi_device_handle(adev);
495 lookup.index = index;
496
497 ret = acpi_dev_get_resources(adev, &resource_list,
498 i2c_acpi_fill_info, &lookup);
499 if (ret < 0)
500 return ERR_PTR(ret);
501
502 acpi_dev_free_resource_list(&resource_list);
503
504 if (!info->addr)
505 return ERR_PTR(-EADDRNOTAVAIL);
506
507 adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
508 if (!adapter)
509 return ERR_PTR(-EPROBE_DEFER);
510
511 return i2c_new_client_device(adapter, info);
512}
513EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
514
515#ifdef CONFIG_ACPI_I2C_OPREGION
516static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
517 u8 cmd, u8 *data, u8 data_len)
518{
519
520 struct i2c_msg msgs[2];
521 int ret;
522 u8 *buffer;
523
524 buffer = kzalloc(data_len, GFP_KERNEL);
525 if (!buffer)
526 return AE_NO_MEMORY;
527
528 msgs[0].addr = client->addr;
529 msgs[0].flags = client->flags;
530 msgs[0].len = 1;
531 msgs[0].buf = &cmd;
532
533 msgs[1].addr = client->addr;
534 msgs[1].flags = client->flags | I2C_M_RD;
535 msgs[1].len = data_len;
536 msgs[1].buf = buffer;
537
538 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
539 if (ret < 0) {
540
541 if (ret == -EREMOTEIO)
542 dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
543 data_len, client->addr, cmd, ret);
544 else
545 dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
546 data_len, client->addr, cmd, ret);
547
548 } else if (ret == 2) {
549 memcpy(data, buffer, data_len);
550 ret = 0;
551 } else {
552 ret = -EIO;
553 }
554
555 kfree(buffer);
556 return ret;
557}
558
559static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
560 u8 cmd, u8 *data, u8 data_len)
561{
562
563 struct i2c_msg msgs[1];
564 u8 *buffer;
565 int ret = AE_OK;
566
567 buffer = kzalloc(data_len + 1, GFP_KERNEL);
568 if (!buffer)
569 return AE_NO_MEMORY;
570
571 buffer[0] = cmd;
572 memcpy(buffer + 1, data, data_len);
573
574 msgs[0].addr = client->addr;
575 msgs[0].flags = client->flags;
576 msgs[0].len = data_len + 1;
577 msgs[0].buf = buffer;
578
579 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
580
581 kfree(buffer);
582
583 if (ret < 0) {
584 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
585 return ret;
586 }
587
588
589 return (ret == 1) ? 0 : -EIO;
590}
591
592static acpi_status
593i2c_acpi_space_handler(u32 function, acpi_physical_address command,
594 u32 bits, u64 *value64,
595 void *handler_context, void *region_context)
596{
597 struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
598 struct i2c_acpi_handler_data *data = handler_context;
599 struct acpi_connection_info *info = &data->info;
600 struct acpi_resource_i2c_serialbus *sb;
601 struct i2c_adapter *adapter = data->adapter;
602 struct i2c_client *client;
603 struct acpi_resource *ares;
604 u32 accessor_type = function >> 16;
605 u8 action = function & ACPI_IO_MASK;
606 acpi_status ret;
607 int status;
608
609 ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
610 if (ACPI_FAILURE(ret))
611 return ret;
612
613 client = kzalloc(sizeof(*client), GFP_KERNEL);
614 if (!client) {
615 ret = AE_NO_MEMORY;
616 goto err;
617 }
618
619 if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
620 ret = AE_BAD_PARAMETER;
621 goto err;
622 }
623
624 client->adapter = adapter;
625 client->addr = sb->slave_address;
626
627 if (sb->access_mode == ACPI_I2C_10BIT_MODE)
628 client->flags |= I2C_CLIENT_TEN;
629
630 switch (accessor_type) {
631 case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
632 if (action == ACPI_READ) {
633 status = i2c_smbus_read_byte(client);
634 if (status >= 0) {
635 gsb->bdata = status;
636 status = 0;
637 }
638 } else {
639 status = i2c_smbus_write_byte(client, gsb->bdata);
640 }
641 break;
642
643 case ACPI_GSB_ACCESS_ATTRIB_BYTE:
644 if (action == ACPI_READ) {
645 status = i2c_smbus_read_byte_data(client, command);
646 if (status >= 0) {
647 gsb->bdata = status;
648 status = 0;
649 }
650 } else {
651 status = i2c_smbus_write_byte_data(client, command,
652 gsb->bdata);
653 }
654 break;
655
656 case ACPI_GSB_ACCESS_ATTRIB_WORD:
657 if (action == ACPI_READ) {
658 status = i2c_smbus_read_word_data(client, command);
659 if (status >= 0) {
660 gsb->wdata = status;
661 status = 0;
662 }
663 } else {
664 status = i2c_smbus_write_word_data(client, command,
665 gsb->wdata);
666 }
667 break;
668
669 case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
670 if (action == ACPI_READ) {
671 status = i2c_smbus_read_block_data(client, command,
672 gsb->data);
673 if (status >= 0) {
674 gsb->len = status;
675 status = 0;
676 }
677 } else {
678 status = i2c_smbus_write_block_data(client, command,
679 gsb->len, gsb->data);
680 }
681 break;
682
683 case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
684 if (action == ACPI_READ) {
685 status = acpi_gsb_i2c_read_bytes(client, command,
686 gsb->data, info->access_length);
687 } else {
688 status = acpi_gsb_i2c_write_bytes(client, command,
689 gsb->data, info->access_length);
690 }
691 break;
692
693 default:
694 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
695 accessor_type, client->addr);
696 ret = AE_BAD_PARAMETER;
697 goto err;
698 }
699
700 gsb->status = status;
701
702 err:
703 kfree(client);
704 ACPI_FREE(ares);
705 return ret;
706}
707
708
709int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
710{
711 acpi_handle handle;
712 struct i2c_acpi_handler_data *data;
713 acpi_status status;
714
715 if (!adapter->dev.parent)
716 return -ENODEV;
717
718 handle = ACPI_HANDLE(adapter->dev.parent);
719
720 if (!handle)
721 return -ENODEV;
722
723 data = kzalloc(sizeof(struct i2c_acpi_handler_data),
724 GFP_KERNEL);
725 if (!data)
726 return -ENOMEM;
727
728 data->adapter = adapter;
729 status = acpi_bus_attach_private_data(handle, (void *)data);
730 if (ACPI_FAILURE(status)) {
731 kfree(data);
732 return -ENOMEM;
733 }
734
735 status = acpi_install_address_space_handler(handle,
736 ACPI_ADR_SPACE_GSBUS,
737 &i2c_acpi_space_handler,
738 NULL,
739 data);
740 if (ACPI_FAILURE(status)) {
741 dev_err(&adapter->dev, "Error installing i2c space handler\n");
742 acpi_bus_detach_private_data(handle);
743 kfree(data);
744 return -ENOMEM;
745 }
746
747 return 0;
748}
749
750void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
751{
752 acpi_handle handle;
753 struct i2c_acpi_handler_data *data;
754 acpi_status status;
755
756 if (!adapter->dev.parent)
757 return;
758
759 handle = ACPI_HANDLE(adapter->dev.parent);
760
761 if (!handle)
762 return;
763
764 acpi_remove_address_space_handler(handle,
765 ACPI_ADR_SPACE_GSBUS,
766 &i2c_acpi_space_handler);
767
768 status = acpi_bus_get_private_data(handle, (void **)&data);
769 if (ACPI_SUCCESS(status))
770 kfree(data);
771
772 acpi_bus_detach_private_data(handle);
773}
774#endif
775