treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
[muen/linux.git] / drivers / i2c / i2c-core-acpi.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Linux I2C core ACPI support code
4  *
5  * Copyright (C) 2014 Intel Corp, Author: Lan Tianyu <tianyu.lan@intel.com>
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 };
43
44 /**
45  * i2c_acpi_get_i2c_resource - Gets I2cSerialBus resource if type matches
46  * @ares:       ACPI resource
47  * @i2c:        Pointer to I2cSerialBus resource will be returned here
48  *
49  * Checks if the given ACPI resource is of type I2cSerialBus.
50  * In this case, returns a pointer to it to the caller.
51  *
52  * Returns true if resource type is of I2cSerialBus, otherwise false.
53  */
54 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
55                                struct acpi_resource_i2c_serialbus **i2c)
56 {
57         struct acpi_resource_i2c_serialbus *sb;
58
59         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
60                 return false;
61
62         sb = &ares->data.i2c_serial_bus;
63         if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
64                 return false;
65
66         *i2c = sb;
67         return true;
68 }
69 EXPORT_SYMBOL_GPL(i2c_acpi_get_i2c_resource);
70
71 static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
72 {
73         struct i2c_acpi_lookup *lookup = data;
74         struct i2c_board_info *info = lookup->info;
75         struct acpi_resource_i2c_serialbus *sb;
76         acpi_status status;
77
78         if (info->addr || !i2c_acpi_get_i2c_resource(ares, &sb))
79                 return 1;
80
81         if (lookup->index != -1 && lookup->n++ != lookup->index)
82                 return 1;
83
84         status = acpi_get_handle(lookup->device_handle,
85                                  sb->resource_source.string_ptr,
86                                  &lookup->adapter_handle);
87         if (ACPI_FAILURE(status))
88                 return 1;
89
90         info->addr = sb->slave_address;
91         lookup->speed = sb->connection_speed;
92         if (sb->access_mode == ACPI_I2C_10BIT_MODE)
93                 info->flags |= I2C_CLIENT_TEN;
94
95         return 1;
96 }
97
98 static const struct acpi_device_id i2c_acpi_ignored_device_ids[] = {
99         /*
100          * ACPI video acpi_devices, which are handled by the acpi-video driver
101          * sometimes contain a SERIAL_TYPE_I2C ACPI resource, ignore these.
102          */
103         { ACPI_VIDEO_HID, 0 },
104         {}
105 };
106
107 static int i2c_acpi_do_lookup(struct acpi_device *adev,
108                               struct i2c_acpi_lookup *lookup)
109 {
110         struct i2c_board_info *info = lookup->info;
111         struct list_head resource_list;
112         int ret;
113
114         if (acpi_bus_get_status(adev) || !adev->status.present ||
115             acpi_device_enumerated(adev))
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         /* Look up for I2cSerialBus resource */
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_get_info(struct acpi_device *adev,
137                              struct i2c_board_info *info,
138                              struct i2c_adapter *adapter,
139                              acpi_handle *adapter_handle)
140 {
141         struct list_head resource_list;
142         struct resource_entry *entry;
143         struct i2c_acpi_lookup lookup;
144         int ret;
145
146         memset(&lookup, 0, sizeof(lookup));
147         lookup.info = info;
148         lookup.index = -1;
149
150         ret = i2c_acpi_do_lookup(adev, &lookup);
151         if (ret)
152                 return ret;
153
154         if (adapter) {
155                 /* The adapter must match the one in I2cSerialBus() connector */
156                 if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
157                         return -ENODEV;
158         } else {
159                 struct acpi_device *adapter_adev;
160
161                 /* The adapter must be present */
162                 if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev))
163                         return -ENODEV;
164                 if (acpi_bus_get_status(adapter_adev) ||
165                     !adapter_adev->status.present)
166                         return -ENODEV;
167         }
168
169         info->fwnode = acpi_fwnode_handle(adev);
170         if (adapter_handle)
171                 *adapter_handle = lookup.adapter_handle;
172
173         /* Then fill IRQ number if any */
174         INIT_LIST_HEAD(&resource_list);
175         ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
176         if (ret < 0)
177                 return -EINVAL;
178
179         resource_list_for_each_entry(entry, &resource_list) {
180                 if (resource_type(entry->res) == IORESOURCE_IRQ) {
181                         info->irq = entry->res->start;
182                         break;
183                 }
184         }
185
186         acpi_dev_free_resource_list(&resource_list);
187
188         acpi_set_modalias(adev, dev_name(&adev->dev), info->type,
189                           sizeof(info->type));
190
191         return 0;
192 }
193
194 static void i2c_acpi_register_device(struct i2c_adapter *adapter,
195                                      struct acpi_device *adev,
196                                      struct i2c_board_info *info)
197 {
198         adev->power.flags.ignore_parent = true;
199         acpi_device_set_enumerated(adev);
200
201         if (!i2c_new_device(adapter, info)) {
202                 adev->power.flags.ignore_parent = false;
203                 dev_err(&adapter->dev,
204                         "failed to add I2C device %s from ACPI\n",
205                         dev_name(&adev->dev));
206         }
207 }
208
209 static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
210                                        void *data, void **return_value)
211 {
212         struct i2c_adapter *adapter = data;
213         struct acpi_device *adev;
214         struct i2c_board_info info;
215
216         if (acpi_bus_get_device(handle, &adev))
217                 return AE_OK;
218
219         if (i2c_acpi_get_info(adev, &info, adapter, NULL))
220                 return AE_OK;
221
222         i2c_acpi_register_device(adapter, adev, &info);
223
224         return AE_OK;
225 }
226
227 #define I2C_ACPI_MAX_SCAN_DEPTH 32
228
229 /**
230  * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter
231  * @adap: pointer to adapter
232  *
233  * Enumerate all I2C slave devices behind this adapter by walking the ACPI
234  * namespace. When a device is found it will be added to the Linux device
235  * model and bound to the corresponding ACPI handle.
236  */
237 void i2c_acpi_register_devices(struct i2c_adapter *adap)
238 {
239         acpi_status status;
240
241         if (!has_acpi_companion(&adap->dev))
242                 return;
243
244         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
245                                      I2C_ACPI_MAX_SCAN_DEPTH,
246                                      i2c_acpi_add_device, NULL,
247                                      adap, NULL);
248         if (ACPI_FAILURE(status))
249                 dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
250 }
251
252 const struct acpi_device_id *
253 i2c_acpi_match_device(const struct acpi_device_id *matches,
254                       struct i2c_client *client)
255 {
256         if (!(client && matches))
257                 return NULL;
258
259         return acpi_match_device(matches, &client->dev);
260 }
261
262 static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
263                                            void *data, void **return_value)
264 {
265         struct i2c_acpi_lookup *lookup = data;
266         struct acpi_device *adev;
267
268         if (acpi_bus_get_device(handle, &adev))
269                 return AE_OK;
270
271         if (i2c_acpi_do_lookup(adev, lookup))
272                 return AE_OK;
273
274         if (lookup->search_handle != lookup->adapter_handle)
275                 return AE_OK;
276
277         if (lookup->speed <= lookup->min_speed)
278                 lookup->min_speed = lookup->speed;
279
280         return AE_OK;
281 }
282
283 /**
284  * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI
285  * @dev: The device owning the bus
286  *
287  * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves
288  * devices connected to this bus and use the speed of slowest device.
289  *
290  * Returns the speed in Hz or zero
291  */
292 u32 i2c_acpi_find_bus_speed(struct device *dev)
293 {
294         struct i2c_acpi_lookup lookup;
295         struct i2c_board_info dummy;
296         acpi_status status;
297
298         if (!has_acpi_companion(dev))
299                 return 0;
300
301         memset(&lookup, 0, sizeof(lookup));
302         lookup.search_handle = ACPI_HANDLE(dev);
303         lookup.min_speed = UINT_MAX;
304         lookup.info = &dummy;
305         lookup.index = -1;
306
307         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
308                                      I2C_ACPI_MAX_SCAN_DEPTH,
309                                      i2c_acpi_lookup_speed, NULL,
310                                      &lookup, NULL);
311
312         if (ACPI_FAILURE(status)) {
313                 dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
314                 return 0;
315         }
316
317         return lookup.min_speed != UINT_MAX ? lookup.min_speed : 0;
318 }
319 EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
320
321 static int i2c_acpi_find_match_adapter(struct device *dev, void *data)
322 {
323         struct i2c_adapter *adapter = i2c_verify_adapter(dev);
324
325         if (!adapter)
326                 return 0;
327
328         return ACPI_HANDLE(dev) == (acpi_handle)data;
329 }
330
331 static int i2c_acpi_find_match_device(struct device *dev, void *data)
332 {
333         return ACPI_COMPANION(dev) == data;
334 }
335
336 static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
337 {
338         struct device *dev;
339
340         dev = bus_find_device(&i2c_bus_type, NULL, handle,
341                               i2c_acpi_find_match_adapter);
342         return dev ? i2c_verify_adapter(dev) : NULL;
343 }
344
345 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
346 {
347         struct device *dev;
348
349         dev = bus_find_device(&i2c_bus_type, NULL, adev,
350                               i2c_acpi_find_match_device);
351         return dev ? i2c_verify_client(dev) : NULL;
352 }
353
354 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
355                            void *arg)
356 {
357         struct acpi_device *adev = arg;
358         struct i2c_board_info info;
359         acpi_handle adapter_handle;
360         struct i2c_adapter *adapter;
361         struct i2c_client *client;
362
363         switch (value) {
364         case ACPI_RECONFIG_DEVICE_ADD:
365                 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
366                         break;
367
368                 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
369                 if (!adapter)
370                         break;
371
372                 i2c_acpi_register_device(adapter, adev, &info);
373                 break;
374         case ACPI_RECONFIG_DEVICE_REMOVE:
375                 if (!acpi_device_enumerated(adev))
376                         break;
377
378                 client = i2c_acpi_find_client_by_adev(adev);
379                 if (!client)
380                         break;
381
382                 i2c_unregister_device(client);
383                 put_device(&client->dev);
384                 break;
385         }
386
387         return NOTIFY_OK;
388 }
389
390 struct notifier_block i2c_acpi_notifier = {
391         .notifier_call = i2c_acpi_notify,
392 };
393
394 /**
395  * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource
396  * @dev:     Device owning the ACPI resources to get the client from
397  * @index:   Index of ACPI resource to get
398  * @info:    describes the I2C device; note this is modified (addr gets set)
399  * Context: can sleep
400  *
401  * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
402  * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus
403  * resources, in that case this function can be used to create an i2c-client
404  * for other I2cSerialBus resources in the Current Resource Settings table.
405  *
406  * Also see i2c_new_device, which this function calls to create the i2c-client.
407  *
408  * Returns a pointer to the new i2c-client, or error pointer in case of failure.
409  * Specifically, -EPROBE_DEFER is returned if the adapter is not found.
410  */
411 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
412                                        struct i2c_board_info *info)
413 {
414         struct i2c_acpi_lookup lookup;
415         struct i2c_adapter *adapter;
416         struct i2c_client *client;
417         struct acpi_device *adev;
418         LIST_HEAD(resource_list);
419         int ret;
420
421         adev = ACPI_COMPANION(dev);
422         if (!adev)
423                 return ERR_PTR(-EINVAL);
424
425         memset(&lookup, 0, sizeof(lookup));
426         lookup.info = info;
427         lookup.device_handle = acpi_device_handle(adev);
428         lookup.index = index;
429
430         ret = acpi_dev_get_resources(adev, &resource_list,
431                                      i2c_acpi_fill_info, &lookup);
432         if (ret < 0)
433                 return ERR_PTR(ret);
434
435         acpi_dev_free_resource_list(&resource_list);
436
437         if (!info->addr)
438                 return ERR_PTR(-EADDRNOTAVAIL);
439
440         adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
441         if (!adapter)
442                 return ERR_PTR(-EPROBE_DEFER);
443
444         client = i2c_new_device(adapter, info);
445         if (!client)
446                 return ERR_PTR(-ENODEV);
447
448         return client;
449 }
450 EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
451
452 #ifdef CONFIG_ACPI_I2C_OPREGION
453 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
454                 u8 cmd, u8 *data, u8 data_len)
455 {
456
457         struct i2c_msg msgs[2];
458         int ret;
459         u8 *buffer;
460
461         buffer = kzalloc(data_len, GFP_KERNEL);
462         if (!buffer)
463                 return AE_NO_MEMORY;
464
465         msgs[0].addr = client->addr;
466         msgs[0].flags = client->flags;
467         msgs[0].len = 1;
468         msgs[0].buf = &cmd;
469
470         msgs[1].addr = client->addr;
471         msgs[1].flags = client->flags | I2C_M_RD;
472         msgs[1].len = data_len;
473         msgs[1].buf = buffer;
474
475         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
476         if (ret < 0) {
477                 /* Getting a NACK is unfortunately normal with some DSTDs */
478                 if (ret == -EREMOTEIO)
479                         dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
480                                 data_len, client->addr, cmd, ret);
481                 else
482                         dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
483                                 data_len, client->addr, cmd, ret);
484         /* 2 transfers must have completed successfully */
485         } else if (ret == 2) {
486                 memcpy(data, buffer, data_len);
487                 ret = 0;
488         } else {
489                 ret = -EIO;
490         }
491
492         kfree(buffer);
493         return ret;
494 }
495
496 static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
497                 u8 cmd, u8 *data, u8 data_len)
498 {
499
500         struct i2c_msg msgs[1];
501         u8 *buffer;
502         int ret = AE_OK;
503
504         buffer = kzalloc(data_len + 1, GFP_KERNEL);
505         if (!buffer)
506                 return AE_NO_MEMORY;
507
508         buffer[0] = cmd;
509         memcpy(buffer + 1, data, data_len);
510
511         msgs[0].addr = client->addr;
512         msgs[0].flags = client->flags;
513         msgs[0].len = data_len + 1;
514         msgs[0].buf = buffer;
515
516         ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
517
518         kfree(buffer);
519
520         if (ret < 0) {
521                 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
522                 return ret;
523         }
524
525         /* 1 transfer must have completed successfully */
526         return (ret == 1) ? 0 : -EIO;
527 }
528
529 static acpi_status
530 i2c_acpi_space_handler(u32 function, acpi_physical_address command,
531                         u32 bits, u64 *value64,
532                         void *handler_context, void *region_context)
533 {
534         struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
535         struct i2c_acpi_handler_data *data = handler_context;
536         struct acpi_connection_info *info = &data->info;
537         struct acpi_resource_i2c_serialbus *sb;
538         struct i2c_adapter *adapter = data->adapter;
539         struct i2c_client *client;
540         struct acpi_resource *ares;
541         u32 accessor_type = function >> 16;
542         u8 action = function & ACPI_IO_MASK;
543         acpi_status ret;
544         int status;
545
546         ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
547         if (ACPI_FAILURE(ret))
548                 return ret;
549
550         client = kzalloc(sizeof(*client), GFP_KERNEL);
551         if (!client) {
552                 ret = AE_NO_MEMORY;
553                 goto err;
554         }
555
556         if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
557                 ret = AE_BAD_PARAMETER;
558                 goto err;
559         }
560
561         client->adapter = adapter;
562         client->addr = sb->slave_address;
563
564         if (sb->access_mode == ACPI_I2C_10BIT_MODE)
565                 client->flags |= I2C_CLIENT_TEN;
566
567         switch (accessor_type) {
568         case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
569                 if (action == ACPI_READ) {
570                         status = i2c_smbus_read_byte(client);
571                         if (status >= 0) {
572                                 gsb->bdata = status;
573                                 status = 0;
574                         }
575                 } else {
576                         status = i2c_smbus_write_byte(client, gsb->bdata);
577                 }
578                 break;
579
580         case ACPI_GSB_ACCESS_ATTRIB_BYTE:
581                 if (action == ACPI_READ) {
582                         status = i2c_smbus_read_byte_data(client, command);
583                         if (status >= 0) {
584                                 gsb->bdata = status;
585                                 status = 0;
586                         }
587                 } else {
588                         status = i2c_smbus_write_byte_data(client, command,
589                                         gsb->bdata);
590                 }
591                 break;
592
593         case ACPI_GSB_ACCESS_ATTRIB_WORD:
594                 if (action == ACPI_READ) {
595                         status = i2c_smbus_read_word_data(client, command);
596                         if (status >= 0) {
597                                 gsb->wdata = status;
598                                 status = 0;
599                         }
600                 } else {
601                         status = i2c_smbus_write_word_data(client, command,
602                                         gsb->wdata);
603                 }
604                 break;
605
606         case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
607                 if (action == ACPI_READ) {
608                         status = i2c_smbus_read_block_data(client, command,
609                                         gsb->data);
610                         if (status >= 0) {
611                                 gsb->len = status;
612                                 status = 0;
613                         }
614                 } else {
615                         status = i2c_smbus_write_block_data(client, command,
616                                         gsb->len, gsb->data);
617                 }
618                 break;
619
620         case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
621                 if (action == ACPI_READ) {
622                         status = acpi_gsb_i2c_read_bytes(client, command,
623                                         gsb->data, info->access_length);
624                 } else {
625                         status = acpi_gsb_i2c_write_bytes(client, command,
626                                         gsb->data, info->access_length);
627                 }
628                 break;
629
630         default:
631                 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
632                          accessor_type, client->addr);
633                 ret = AE_BAD_PARAMETER;
634                 goto err;
635         }
636
637         gsb->status = status;
638
639  err:
640         kfree(client);
641         ACPI_FREE(ares);
642         return ret;
643 }
644
645
646 int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
647 {
648         acpi_handle handle;
649         struct i2c_acpi_handler_data *data;
650         acpi_status status;
651
652         if (!adapter->dev.parent)
653                 return -ENODEV;
654
655         handle = ACPI_HANDLE(adapter->dev.parent);
656
657         if (!handle)
658                 return -ENODEV;
659
660         data = kzalloc(sizeof(struct i2c_acpi_handler_data),
661                             GFP_KERNEL);
662         if (!data)
663                 return -ENOMEM;
664
665         data->adapter = adapter;
666         status = acpi_bus_attach_private_data(handle, (void *)data);
667         if (ACPI_FAILURE(status)) {
668                 kfree(data);
669                 return -ENOMEM;
670         }
671
672         status = acpi_install_address_space_handler(handle,
673                                 ACPI_ADR_SPACE_GSBUS,
674                                 &i2c_acpi_space_handler,
675                                 NULL,
676                                 data);
677         if (ACPI_FAILURE(status)) {
678                 dev_err(&adapter->dev, "Error installing i2c space handler\n");
679                 acpi_bus_detach_private_data(handle);
680                 kfree(data);
681                 return -ENOMEM;
682         }
683
684         acpi_walk_dep_device_list(handle);
685         return 0;
686 }
687
688 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
689 {
690         acpi_handle handle;
691         struct i2c_acpi_handler_data *data;
692         acpi_status status;
693
694         if (!adapter->dev.parent)
695                 return;
696
697         handle = ACPI_HANDLE(adapter->dev.parent);
698
699         if (!handle)
700                 return;
701
702         acpi_remove_address_space_handler(handle,
703                                 ACPI_ADR_SPACE_GSBUS,
704                                 &i2c_acpi_space_handler);
705
706         status = acpi_bus_get_private_data(handle, (void **)&data);
707         if (ACPI_SUCCESS(status))
708                 kfree(data);
709
710         acpi_bus_detach_private_data(handle);
711 }
712 #endif /* CONFIG_ACPI_I2C_OPREGION */