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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
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 * i2c_acpi_get_i2c_resource - Gets I2cSerialBus resource if type matches
47 * @ares: ACPI resource
48 * @i2c: Pointer to I2cSerialBus resource will be returned here
49 *
50 * Checks if the given ACPI resource is of type I2cSerialBus.
51 * In this case, returns a pointer to it to the caller.
52 *
53 * Returns true if resource type is of I2cSerialBus, otherwise false.
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 * ACPI video acpi_devices, which are handled by the acpi-video driver
102 * sometimes contain a SERIAL_TYPE_I2C ACPI resource, ignore these.
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 /* 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
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; /* No need to add resource to the list */
145}
146
147/**
148 * i2c_acpi_get_irq - get device IRQ number from ACPI
149 * @client: Pointer to the I2C client device
150 *
151 * Find the IRQ number used by a specific client device.
152 *
153 * Return: The IRQ number or an error code.
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 /* The adapter must match the one in I2cSerialBus() connector */
198 if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
199 return -ENODEV;
200 } else {
201 struct acpi_device *adapter_adev;
202
203 /* The adapter must be present */
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}
231
232static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
233 void *data, void **return_value)
234{
235 struct i2c_adapter *adapter = data;
236 struct acpi_device *adev;
237 struct i2c_board_info info;
238
239 if (acpi_bus_get_device(handle, &adev))
240 return AE_OK;
241
242 if (i2c_acpi_get_info(adev, &info, adapter, NULL))
243 return AE_OK;
244
245 i2c_acpi_register_device(adapter, adev, &info);
246
247 return AE_OK;
248}
249
250#define I2C_ACPI_MAX_SCAN_DEPTH 32
251
252/**
253 * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter
254 * @adap: pointer to adapter
255 *
256 * Enumerate all I2C slave devices behind this adapter by walking the ACPI
257 * namespace. When a device is found it will be added to the Linux device
258 * model and bound to the corresponding ACPI handle.
259 */
260void i2c_acpi_register_devices(struct i2c_adapter *adap)
261{
262 struct acpi_device *adev;
263 acpi_status status;
264
265 if (!has_acpi_companion(&adap->dev))
266 return;
267
268 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
269 I2C_ACPI_MAX_SCAN_DEPTH,
270 i2c_acpi_add_device, NULL,
271 adap, NULL);
272 if (ACPI_FAILURE(status))
273 dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
274
275 if (!adap->dev.parent)
276 return;
277
278 adev = ACPI_COMPANION(adap->dev.parent);
279 if (!adev)
280 return;
281
282 acpi_dev_clear_dependencies(adev);
283}
284
285static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
286 /*
287 * These Silead touchscreen controllers only work at 400KHz, for
288 * some reason they do not work at 100KHz. On some devices the ACPI
289 * tables list another device at their bus as only being capable
290 * of 100KHz, testing has shown that these other devices work fine
291 * at 400KHz (as can be expected of any recent i2c hw) so we force
292 * the speed of the bus to 400 KHz if a Silead device is present.
293 */
294 { "MSSL1680", 0 },
295 {}
296};
297
298static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
299 void *data, void **return_value)
300{
301 struct i2c_acpi_lookup *lookup = data;
302 struct acpi_device *adev;
303
304 if (acpi_bus_get_device(handle, &adev))
305 return AE_OK;
306
307 if (i2c_acpi_do_lookup(adev, lookup))
308 return AE_OK;
309
310 if (lookup->search_handle != lookup->adapter_handle)
311 return AE_OK;
312
313 if (lookup->speed <= lookup->min_speed)
314 lookup->min_speed = lookup->speed;
315
316 if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)
317 lookup->force_speed = I2C_MAX_FAST_MODE_FREQ;
318
319 return AE_OK;
320}
321
322/**
323 * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI
324 * @dev: The device owning the bus
325 *
326 * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves
327 * devices connected to this bus and use the speed of slowest device.
328 *
329 * Returns the speed in Hz or zero
330 */
331u32 i2c_acpi_find_bus_speed(struct device *dev)
332{
333 struct i2c_acpi_lookup lookup;
334 struct i2c_board_info dummy;
335 acpi_status status;
336
337 if (!has_acpi_companion(dev))
338 return 0;
339
340 memset(&lookup, 0, sizeof(lookup));
341 lookup.search_handle = ACPI_HANDLE(dev);
342 lookup.min_speed = UINT_MAX;
343 lookup.info = &dummy;
344 lookup.index = -1;
345
346 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
347 I2C_ACPI_MAX_SCAN_DEPTH,
348 i2c_acpi_lookup_speed, NULL,
349 &lookup, NULL);
350
351 if (ACPI_FAILURE(status)) {
352 dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
353 return 0;
354 }
355
356 if (lookup.force_speed) {
357 if (lookup.force_speed != lookup.min_speed)
358 dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n",
359 lookup.min_speed, lookup.force_speed);
360 return lookup.force_speed;
361 } else if (lookup.min_speed != UINT_MAX) {
362 return lookup.min_speed;
363 } else {
364 return 0;
365 }
366}
367EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
368
369static int i2c_acpi_find_match_adapter(struct device *dev, const void *data)
370{
371 struct i2c_adapter *adapter = i2c_verify_adapter(dev);
372
373 if (!adapter)
374 return 0;
375
376 return ACPI_HANDLE(dev) == (acpi_handle)data;
377}
378
379struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
380{
381 struct device *dev;
382
383 dev = bus_find_device(&i2c_bus_type, NULL, handle,
384 i2c_acpi_find_match_adapter);
385
386 return dev ? i2c_verify_adapter(dev) : NULL;
387}
388EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
389
390static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
391{
392 struct device *dev;
393 struct i2c_client *client;
394
395 dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev);
396 if (!dev)
397 return NULL;
398
399 client = i2c_verify_client(dev);
400 if (!client)
401 put_device(dev);
402
403 return client;
404}
405
406static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
407 void *arg)
408{
409 struct acpi_device *adev = arg;
410 struct i2c_board_info info;
411 acpi_handle adapter_handle;
412 struct i2c_adapter *adapter;
413 struct i2c_client *client;
414
415 switch (value) {
416 case ACPI_RECONFIG_DEVICE_ADD:
417 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
418 break;
419
420 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
421 if (!adapter)
422 break;
423
424 i2c_acpi_register_device(adapter, adev, &info);
425 put_device(&adapter->dev);
426 break;
427 case ACPI_RECONFIG_DEVICE_REMOVE:
428 if (!acpi_device_enumerated(adev))
429 break;
430
431 client = i2c_acpi_find_client_by_adev(adev);
432 if (!client)
433 break;
434
435 i2c_unregister_device(client);
436 put_device(&client->dev);
437 break;
438 }
439
440 return NOTIFY_OK;
441}
442
443struct notifier_block i2c_acpi_notifier = {
444 .notifier_call = i2c_acpi_notify,
445};
446
447/**
448 * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource
449 * @dev: Device owning the ACPI resources to get the client from
450 * @index: Index of ACPI resource to get
451 * @info: describes the I2C device; note this is modified (addr gets set)
452 * Context: can sleep
453 *
454 * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
455 * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus
456 * resources, in that case this function can be used to create an i2c-client
457 * for other I2cSerialBus resources in the Current Resource Settings table.
458 *
459 * Also see i2c_new_client_device, which this function calls to create the
460 * i2c-client.
461 *
462 * Returns a pointer to the new i2c-client, or error pointer in case of failure.
463 * Specifically, -EPROBE_DEFER is returned if the adapter is not found.
464 */
465struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
466 struct i2c_board_info *info)
467{
468 struct acpi_device *adev = ACPI_COMPANION(dev);
469 struct i2c_acpi_lookup lookup;
470 struct i2c_adapter *adapter;
471 LIST_HEAD(resource_list);
472 int ret;
473
474 memset(&lookup, 0, sizeof(lookup));
475 lookup.info = info;
476 lookup.device_handle = acpi_device_handle(adev);
477 lookup.index = index;
478
479 ret = acpi_dev_get_resources(adev, &resource_list,
480 i2c_acpi_fill_info, &lookup);
481 if (ret < 0)
482 return ERR_PTR(ret);
483
484 acpi_dev_free_resource_list(&resource_list);
485
486 if (!info->addr)
487 return ERR_PTR(-EADDRNOTAVAIL);
488
489 adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
490 if (!adapter)
491 return ERR_PTR(-EPROBE_DEFER);
492
493 return i2c_new_client_device(adapter, info);
494}
495EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
496
497#ifdef CONFIG_ACPI_I2C_OPREGION
498static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
499 u8 cmd, u8 *data, u8 data_len)
500{
501
502 struct i2c_msg msgs[2];
503 int ret;
504 u8 *buffer;
505
506 buffer = kzalloc(data_len, GFP_KERNEL);
507 if (!buffer)
508 return AE_NO_MEMORY;
509
510 msgs[0].addr = client->addr;
511 msgs[0].flags = client->flags;
512 msgs[0].len = 1;
513 msgs[0].buf = &cmd;
514
515 msgs[1].addr = client->addr;
516 msgs[1].flags = client->flags | I2C_M_RD;
517 msgs[1].len = data_len;
518 msgs[1].buf = buffer;
519
520 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
521 if (ret < 0) {
522 /* Getting a NACK is unfortunately normal with some DSTDs */
523 if (ret == -EREMOTEIO)
524 dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
525 data_len, client->addr, cmd, ret);
526 else
527 dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
528 data_len, client->addr, cmd, ret);
529 /* 2 transfers must have completed successfully */
530 } else if (ret == 2) {
531 memcpy(data, buffer, data_len);
532 ret = 0;
533 } else {
534 ret = -EIO;
535 }
536
537 kfree(buffer);
538 return ret;
539}
540
541static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
542 u8 cmd, u8 *data, u8 data_len)
543{
544
545 struct i2c_msg msgs[1];
546 u8 *buffer;
547 int ret = AE_OK;
548
549 buffer = kzalloc(data_len + 1, GFP_KERNEL);
550 if (!buffer)
551 return AE_NO_MEMORY;
552
553 buffer[0] = cmd;
554 memcpy(buffer + 1, data, data_len);
555
556 msgs[0].addr = client->addr;
557 msgs[0].flags = client->flags;
558 msgs[0].len = data_len + 1;
559 msgs[0].buf = buffer;
560
561 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
562
563 kfree(buffer);
564
565 if (ret < 0) {
566 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
567 return ret;
568 }
569
570 /* 1 transfer must have completed successfully */
571 return (ret == 1) ? 0 : -EIO;
572}
573
574static acpi_status
575i2c_acpi_space_handler(u32 function, acpi_physical_address command,
576 u32 bits, u64 *value64,
577 void *handler_context, void *region_context)
578{
579 struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
580 struct i2c_acpi_handler_data *data = handler_context;
581 struct acpi_connection_info *info = &data->info;
582 struct acpi_resource_i2c_serialbus *sb;
583 struct i2c_adapter *adapter = data->adapter;
584 struct i2c_client *client;
585 struct acpi_resource *ares;
586 u32 accessor_type = function >> 16;
587 u8 action = function & ACPI_IO_MASK;
588 acpi_status ret;
589 int status;
590
591 ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
592 if (ACPI_FAILURE(ret))
593 return ret;
594
595 client = kzalloc(sizeof(*client), GFP_KERNEL);
596 if (!client) {
597 ret = AE_NO_MEMORY;
598 goto err;
599 }
600
601 if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
602 ret = AE_BAD_PARAMETER;
603 goto err;
604 }
605
606 client->adapter = adapter;
607 client->addr = sb->slave_address;
608
609 if (sb->access_mode == ACPI_I2C_10BIT_MODE)
610 client->flags |= I2C_CLIENT_TEN;
611
612 switch (accessor_type) {
613 case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
614 if (action == ACPI_READ) {
615 status = i2c_smbus_read_byte(client);
616 if (status >= 0) {
617 gsb->bdata = status;
618 status = 0;
619 }
620 } else {
621 status = i2c_smbus_write_byte(client, gsb->bdata);
622 }
623 break;
624
625 case ACPI_GSB_ACCESS_ATTRIB_BYTE:
626 if (action == ACPI_READ) {
627 status = i2c_smbus_read_byte_data(client, command);
628 if (status >= 0) {
629 gsb->bdata = status;
630 status = 0;
631 }
632 } else {
633 status = i2c_smbus_write_byte_data(client, command,
634 gsb->bdata);
635 }
636 break;
637
638 case ACPI_GSB_ACCESS_ATTRIB_WORD:
639 if (action == ACPI_READ) {
640 status = i2c_smbus_read_word_data(client, command);
641 if (status >= 0) {
642 gsb->wdata = status;
643 status = 0;
644 }
645 } else {
646 status = i2c_smbus_write_word_data(client, command,
647 gsb->wdata);
648 }
649 break;
650
651 case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
652 if (action == ACPI_READ) {
653 status = i2c_smbus_read_block_data(client, command,
654 gsb->data);
655 if (status >= 0) {
656 gsb->len = status;
657 status = 0;
658 }
659 } else {
660 status = i2c_smbus_write_block_data(client, command,
661 gsb->len, gsb->data);
662 }
663 break;
664
665 case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
666 if (action == ACPI_READ) {
667 status = acpi_gsb_i2c_read_bytes(client, command,
668 gsb->data, info->access_length);
669 } else {
670 status = acpi_gsb_i2c_write_bytes(client, command,
671 gsb->data, info->access_length);
672 }
673 break;
674
675 default:
676 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
677 accessor_type, client->addr);
678 ret = AE_BAD_PARAMETER;
679 goto err;
680 }
681
682 gsb->status = status;
683
684 err:
685 kfree(client);
686 ACPI_FREE(ares);
687 return ret;
688}
689
690
691int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
692{
693 acpi_handle handle;
694 struct i2c_acpi_handler_data *data;
695 acpi_status status;
696
697 if (!adapter->dev.parent)
698 return -ENODEV;
699
700 handle = ACPI_HANDLE(adapter->dev.parent);
701
702 if (!handle)
703 return -ENODEV;
704
705 data = kzalloc(sizeof(struct i2c_acpi_handler_data),
706 GFP_KERNEL);
707 if (!data)
708 return -ENOMEM;
709
710 data->adapter = adapter;
711 status = acpi_bus_attach_private_data(handle, (void *)data);
712 if (ACPI_FAILURE(status)) {
713 kfree(data);
714 return -ENOMEM;
715 }
716
717 status = acpi_install_address_space_handler(handle,
718 ACPI_ADR_SPACE_GSBUS,
719 &i2c_acpi_space_handler,
720 NULL,
721 data);
722 if (ACPI_FAILURE(status)) {
723 dev_err(&adapter->dev, "Error installing i2c space handler\n");
724 acpi_bus_detach_private_data(handle);
725 kfree(data);
726 return -ENOMEM;
727 }
728
729 return 0;
730}
731
732void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
733{
734 acpi_handle handle;
735 struct i2c_acpi_handler_data *data;
736 acpi_status status;
737
738 if (!adapter->dev.parent)
739 return;
740
741 handle = ACPI_HANDLE(adapter->dev.parent);
742
743 if (!handle)
744 return;
745
746 acpi_remove_address_space_handler(handle,
747 ACPI_ADR_SPACE_GSBUS,
748 &i2c_acpi_space_handler);
749
750 status = acpi_bus_get_private_data(handle, (void **)&data);
751 if (ACPI_SUCCESS(status))
752 kfree(data);
753
754 acpi_bus_detach_private_data(handle);
755}
756#endif /* CONFIG_ACPI_I2C_OPREGION */