xref: /openbmc/linux/drivers/i2c/i2c-core-acpi.c (revision d9565bf4)
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 	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  */
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_resource_count(struct acpi_resource *ares, void *data)
73 {
74 	struct acpi_resource_i2c_serialbus *sb;
75 	int *count = data;
76 
77 	if (i2c_acpi_get_i2c_resource(ares, &sb))
78 		*count = *count + 1;
79 
80 	return 1;
81 }
82 
83 /**
84  * i2c_acpi_client_count - Count the number of I2cSerialBus resources
85  * @adev:	ACPI device
86  *
87  * Returns the number of I2cSerialBus resources in the ACPI-device's
88  * resource-list; or a negative error code.
89  */
90 int i2c_acpi_client_count(struct acpi_device *adev)
91 {
92 	int ret, count = 0;
93 	LIST_HEAD(r);
94 
95 	ret = acpi_dev_get_resources(adev, &r, i2c_acpi_resource_count, &count);
96 	if (ret < 0)
97 		return ret;
98 
99 	acpi_dev_free_resource_list(&r);
100 	return count;
101 }
102 EXPORT_SYMBOL_GPL(i2c_acpi_client_count);
103 
104 static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
105 {
106 	struct i2c_acpi_lookup *lookup = data;
107 	struct i2c_board_info *info = lookup->info;
108 	struct acpi_resource_i2c_serialbus *sb;
109 	acpi_status status;
110 
111 	if (info->addr || !i2c_acpi_get_i2c_resource(ares, &sb))
112 		return 1;
113 
114 	if (lookup->index != -1 && lookup->n++ != lookup->index)
115 		return 1;
116 
117 	status = acpi_get_handle(lookup->device_handle,
118 				 sb->resource_source.string_ptr,
119 				 &lookup->adapter_handle);
120 	if (ACPI_FAILURE(status))
121 		return 1;
122 
123 	info->addr = sb->slave_address;
124 	lookup->speed = sb->connection_speed;
125 	if (sb->access_mode == ACPI_I2C_10BIT_MODE)
126 		info->flags |= I2C_CLIENT_TEN;
127 
128 	return 1;
129 }
130 
131 static const struct acpi_device_id i2c_acpi_ignored_device_ids[] = {
132 	/*
133 	 * ACPI video acpi_devices, which are handled by the acpi-video driver
134 	 * sometimes contain a SERIAL_TYPE_I2C ACPI resource, ignore these.
135 	 */
136 	{ ACPI_VIDEO_HID, 0 },
137 	{}
138 };
139 
140 static int i2c_acpi_do_lookup(struct acpi_device *adev,
141 			      struct i2c_acpi_lookup *lookup)
142 {
143 	struct i2c_board_info *info = lookup->info;
144 	struct list_head resource_list;
145 	int ret;
146 
147 	if (acpi_bus_get_status(adev))
148 		return -EINVAL;
149 
150 	if (!acpi_dev_ready_for_enumeration(adev))
151 		return -ENODEV;
152 
153 	if (acpi_match_device_ids(adev, i2c_acpi_ignored_device_ids) == 0)
154 		return -ENODEV;
155 
156 	memset(info, 0, sizeof(*info));
157 	lookup->device_handle = acpi_device_handle(adev);
158 
159 	/* Look up for I2cSerialBus resource */
160 	INIT_LIST_HEAD(&resource_list);
161 	ret = acpi_dev_get_resources(adev, &resource_list,
162 				     i2c_acpi_fill_info, lookup);
163 	acpi_dev_free_resource_list(&resource_list);
164 
165 	if (ret < 0 || !info->addr)
166 		return -EINVAL;
167 
168 	return 0;
169 }
170 
171 static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
172 {
173 	int *irq = data;
174 	struct resource r;
175 
176 	if (*irq <= 0 && acpi_dev_resource_interrupt(ares, 0, &r))
177 		*irq = i2c_dev_irq_from_resources(&r, 1);
178 
179 	return 1; /* No need to add resource to the list */
180 }
181 
182 /**
183  * i2c_acpi_get_irq - get device IRQ number from ACPI
184  * @client: Pointer to the I2C client device
185  *
186  * Find the IRQ number used by a specific client device.
187  *
188  * Return: The IRQ number or an error code.
189  */
190 int i2c_acpi_get_irq(struct i2c_client *client)
191 {
192 	struct acpi_device *adev = ACPI_COMPANION(&client->dev);
193 	struct list_head resource_list;
194 	int irq = -ENOENT;
195 	int ret;
196 
197 	INIT_LIST_HEAD(&resource_list);
198 
199 	ret = acpi_dev_get_resources(adev, &resource_list,
200 				     i2c_acpi_add_resource, &irq);
201 	if (ret < 0)
202 		return ret;
203 
204 	acpi_dev_free_resource_list(&resource_list);
205 
206 	if (irq == -ENOENT)
207 		irq = acpi_dev_gpio_irq_get(adev, 0);
208 
209 	return irq;
210 }
211 
212 static int i2c_acpi_get_info(struct acpi_device *adev,
213 			     struct i2c_board_info *info,
214 			     struct i2c_adapter *adapter,
215 			     acpi_handle *adapter_handle)
216 {
217 	struct i2c_acpi_lookup lookup;
218 	int ret;
219 
220 	memset(&lookup, 0, sizeof(lookup));
221 	lookup.info = info;
222 	lookup.index = -1;
223 
224 	if (acpi_device_enumerated(adev))
225 		return -EINVAL;
226 
227 	ret = i2c_acpi_do_lookup(adev, &lookup);
228 	if (ret)
229 		return ret;
230 
231 	if (adapter) {
232 		/* The adapter must match the one in I2cSerialBus() connector */
233 		if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
234 			return -ENODEV;
235 	} else {
236 		struct acpi_device *adapter_adev;
237 
238 		/* The adapter must be present */
239 		if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev))
240 			return -ENODEV;
241 		if (acpi_bus_get_status(adapter_adev) ||
242 		    !adapter_adev->status.present)
243 			return -ENODEV;
244 	}
245 
246 	info->fwnode = acpi_fwnode_handle(adev);
247 	if (adapter_handle)
248 		*adapter_handle = lookup.adapter_handle;
249 
250 	acpi_set_modalias(adev, dev_name(&adev->dev), info->type,
251 			  sizeof(info->type));
252 
253 	return 0;
254 }
255 
256 static void i2c_acpi_register_device(struct i2c_adapter *adapter,
257 				     struct acpi_device *adev,
258 				     struct i2c_board_info *info)
259 {
260 	/*
261 	 * Skip registration on boards where the ACPI tables are
262 	 * known to contain bogus I2C devices.
263 	 */
264 	if (acpi_quirk_skip_i2c_client_enumeration(adev))
265 		return;
266 
267 	adev->power.flags.ignore_parent = true;
268 	acpi_device_set_enumerated(adev);
269 
270 	if (IS_ERR(i2c_new_client_device(adapter, info)))
271 		adev->power.flags.ignore_parent = false;
272 }
273 
274 static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
275 				       void *data, void **return_value)
276 {
277 	struct i2c_adapter *adapter = data;
278 	struct acpi_device *adev;
279 	struct i2c_board_info info;
280 
281 	if (acpi_bus_get_device(handle, &adev))
282 		return AE_OK;
283 
284 	if (i2c_acpi_get_info(adev, &info, adapter, NULL))
285 		return AE_OK;
286 
287 	i2c_acpi_register_device(adapter, adev, &info);
288 
289 	return AE_OK;
290 }
291 
292 #define I2C_ACPI_MAX_SCAN_DEPTH 32
293 
294 /**
295  * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter
296  * @adap: pointer to adapter
297  *
298  * Enumerate all I2C slave devices behind this adapter by walking the ACPI
299  * namespace. When a device is found it will be added to the Linux device
300  * model and bound to the corresponding ACPI handle.
301  */
302 void i2c_acpi_register_devices(struct i2c_adapter *adap)
303 {
304 	struct acpi_device *adev;
305 	acpi_status status;
306 
307 	if (!has_acpi_companion(&adap->dev))
308 		return;
309 
310 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
311 				     I2C_ACPI_MAX_SCAN_DEPTH,
312 				     i2c_acpi_add_device, NULL,
313 				     adap, NULL);
314 	if (ACPI_FAILURE(status))
315 		dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
316 
317 	if (!adap->dev.parent)
318 		return;
319 
320 	adev = ACPI_COMPANION(adap->dev.parent);
321 	if (!adev)
322 		return;
323 
324 	acpi_dev_clear_dependencies(adev);
325 }
326 
327 static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
328 	/*
329 	 * These Silead touchscreen controllers only work at 400KHz, for
330 	 * some reason they do not work at 100KHz. On some devices the ACPI
331 	 * tables list another device at their bus as only being capable
332 	 * of 100KHz, testing has shown that these other devices work fine
333 	 * at 400KHz (as can be expected of any recent i2c hw) so we force
334 	 * the speed of the bus to 400 KHz if a Silead device is present.
335 	 */
336 	{ "MSSL1680", 0 },
337 	{}
338 };
339 
340 static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
341 					   void *data, void **return_value)
342 {
343 	struct i2c_acpi_lookup *lookup = data;
344 	struct acpi_device *adev;
345 
346 	if (acpi_bus_get_device(handle, &adev))
347 		return AE_OK;
348 
349 	if (i2c_acpi_do_lookup(adev, lookup))
350 		return AE_OK;
351 
352 	if (lookup->search_handle != lookup->adapter_handle)
353 		return AE_OK;
354 
355 	if (lookup->speed <= lookup->min_speed)
356 		lookup->min_speed = lookup->speed;
357 
358 	if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)
359 		lookup->force_speed = I2C_MAX_FAST_MODE_FREQ;
360 
361 	return AE_OK;
362 }
363 
364 /**
365  * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI
366  * @dev: The device owning the bus
367  *
368  * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves
369  * devices connected to this bus and use the speed of slowest device.
370  *
371  * Returns the speed in Hz or zero
372  */
373 u32 i2c_acpi_find_bus_speed(struct device *dev)
374 {
375 	struct i2c_acpi_lookup lookup;
376 	struct i2c_board_info dummy;
377 	acpi_status status;
378 
379 	if (!has_acpi_companion(dev))
380 		return 0;
381 
382 	memset(&lookup, 0, sizeof(lookup));
383 	lookup.search_handle = ACPI_HANDLE(dev);
384 	lookup.min_speed = UINT_MAX;
385 	lookup.info = &dummy;
386 	lookup.index = -1;
387 
388 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
389 				     I2C_ACPI_MAX_SCAN_DEPTH,
390 				     i2c_acpi_lookup_speed, NULL,
391 				     &lookup, NULL);
392 
393 	if (ACPI_FAILURE(status)) {
394 		dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
395 		return 0;
396 	}
397 
398 	if (lookup.force_speed) {
399 		if (lookup.force_speed != lookup.min_speed)
400 			dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n",
401 				 lookup.min_speed, lookup.force_speed);
402 		return lookup.force_speed;
403 	} else if (lookup.min_speed != UINT_MAX) {
404 		return lookup.min_speed;
405 	} else {
406 		return 0;
407 	}
408 }
409 EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
410 
411 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
412 {
413 	struct i2c_adapter *adapter;
414 	struct device *dev;
415 
416 	dev = bus_find_device(&i2c_bus_type, NULL, handle, device_match_acpi_handle);
417 	if (!dev)
418 		return NULL;
419 
420 	adapter = i2c_verify_adapter(dev);
421 	if (!adapter)
422 		put_device(dev);
423 
424 	return adapter;
425 }
426 EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
427 
428 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
429 {
430 	struct device *dev;
431 	struct i2c_client *client;
432 
433 	dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev);
434 	if (!dev)
435 		return NULL;
436 
437 	client = i2c_verify_client(dev);
438 	if (!client)
439 		put_device(dev);
440 
441 	return client;
442 }
443 
444 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
445 			   void *arg)
446 {
447 	struct acpi_device *adev = arg;
448 	struct i2c_board_info info;
449 	acpi_handle adapter_handle;
450 	struct i2c_adapter *adapter;
451 	struct i2c_client *client;
452 
453 	switch (value) {
454 	case ACPI_RECONFIG_DEVICE_ADD:
455 		if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
456 			break;
457 
458 		adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
459 		if (!adapter)
460 			break;
461 
462 		i2c_acpi_register_device(adapter, adev, &info);
463 		put_device(&adapter->dev);
464 		break;
465 	case ACPI_RECONFIG_DEVICE_REMOVE:
466 		if (!acpi_device_enumerated(adev))
467 			break;
468 
469 		client = i2c_acpi_find_client_by_adev(adev);
470 		if (!client)
471 			break;
472 
473 		i2c_unregister_device(client);
474 		put_device(&client->dev);
475 		break;
476 	}
477 
478 	return NOTIFY_OK;
479 }
480 
481 struct notifier_block i2c_acpi_notifier = {
482 	.notifier_call = i2c_acpi_notify,
483 };
484 
485 /**
486  * i2c_acpi_new_device_by_fwnode - Create i2c-client for the Nth I2cSerialBus resource
487  * @fwnode:  fwnode with the ACPI resources to get the client from
488  * @index:   Index of ACPI resource to get
489  * @info:    describes the I2C device; note this is modified (addr gets set)
490  * Context: can sleep
491  *
492  * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
493  * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus
494  * resources, in that case this function can be used to create an i2c-client
495  * for other I2cSerialBus resources in the Current Resource Settings table.
496  *
497  * Also see i2c_new_client_device, which this function calls to create the
498  * i2c-client.
499  *
500  * Returns a pointer to the new i2c-client, or error pointer in case of failure.
501  * Specifically, -EPROBE_DEFER is returned if the adapter is not found.
502  */
503 struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,
504 						 int index,
505 						 struct i2c_board_info *info)
506 {
507 	struct i2c_acpi_lookup lookup;
508 	struct i2c_adapter *adapter;
509 	struct acpi_device *adev;
510 	LIST_HEAD(resource_list);
511 	int ret;
512 
513 	adev = to_acpi_device_node(fwnode);
514 	if (!adev)
515 		return ERR_PTR(-ENODEV);
516 
517 	memset(&lookup, 0, sizeof(lookup));
518 	lookup.info = info;
519 	lookup.device_handle = acpi_device_handle(adev);
520 	lookup.index = index;
521 
522 	ret = acpi_dev_get_resources(adev, &resource_list,
523 				     i2c_acpi_fill_info, &lookup);
524 	if (ret < 0)
525 		return ERR_PTR(ret);
526 
527 	acpi_dev_free_resource_list(&resource_list);
528 
529 	if (!info->addr)
530 		return ERR_PTR(-EADDRNOTAVAIL);
531 
532 	adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
533 	if (!adapter)
534 		return ERR_PTR(-EPROBE_DEFER);
535 
536 	return i2c_new_client_device(adapter, info);
537 }
538 EXPORT_SYMBOL_GPL(i2c_acpi_new_device_by_fwnode);
539 
540 bool i2c_acpi_waive_d0_probe(struct device *dev)
541 {
542 	struct i2c_driver *driver = to_i2c_driver(dev->driver);
543 	struct acpi_device *adev = ACPI_COMPANION(dev);
544 
545 	return driver->flags & I2C_DRV_ACPI_WAIVE_D0_PROBE &&
546 		adev && adev->power.state_for_enumeration >= adev->power.state;
547 }
548 EXPORT_SYMBOL_GPL(i2c_acpi_waive_d0_probe);
549 
550 #ifdef CONFIG_ACPI_I2C_OPREGION
551 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
552 		u8 cmd, u8 *data, u8 data_len)
553 {
554 
555 	struct i2c_msg msgs[2];
556 	int ret;
557 	u8 *buffer;
558 
559 	buffer = kzalloc(data_len, GFP_KERNEL);
560 	if (!buffer)
561 		return AE_NO_MEMORY;
562 
563 	msgs[0].addr = client->addr;
564 	msgs[0].flags = client->flags;
565 	msgs[0].len = 1;
566 	msgs[0].buf = &cmd;
567 
568 	msgs[1].addr = client->addr;
569 	msgs[1].flags = client->flags | I2C_M_RD;
570 	msgs[1].len = data_len;
571 	msgs[1].buf = buffer;
572 
573 	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
574 	if (ret < 0) {
575 		/* Getting a NACK is unfortunately normal with some DSTDs */
576 		if (ret == -EREMOTEIO)
577 			dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
578 				data_len, client->addr, cmd, ret);
579 		else
580 			dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
581 				data_len, client->addr, cmd, ret);
582 	/* 2 transfers must have completed successfully */
583 	} else if (ret == 2) {
584 		memcpy(data, buffer, data_len);
585 		ret = 0;
586 	} else {
587 		ret = -EIO;
588 	}
589 
590 	kfree(buffer);
591 	return ret;
592 }
593 
594 static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
595 		u8 cmd, u8 *data, u8 data_len)
596 {
597 
598 	struct i2c_msg msgs[1];
599 	u8 *buffer;
600 	int ret = AE_OK;
601 
602 	buffer = kzalloc(data_len + 1, GFP_KERNEL);
603 	if (!buffer)
604 		return AE_NO_MEMORY;
605 
606 	buffer[0] = cmd;
607 	memcpy(buffer + 1, data, data_len);
608 
609 	msgs[0].addr = client->addr;
610 	msgs[0].flags = client->flags;
611 	msgs[0].len = data_len + 1;
612 	msgs[0].buf = buffer;
613 
614 	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
615 
616 	kfree(buffer);
617 
618 	if (ret < 0) {
619 		dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
620 		return ret;
621 	}
622 
623 	/* 1 transfer must have completed successfully */
624 	return (ret == 1) ? 0 : -EIO;
625 }
626 
627 static acpi_status
628 i2c_acpi_space_handler(u32 function, acpi_physical_address command,
629 			u32 bits, u64 *value64,
630 			void *handler_context, void *region_context)
631 {
632 	struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
633 	struct i2c_acpi_handler_data *data = handler_context;
634 	struct acpi_connection_info *info = &data->info;
635 	struct acpi_resource_i2c_serialbus *sb;
636 	struct i2c_adapter *adapter = data->adapter;
637 	struct i2c_client *client;
638 	struct acpi_resource *ares;
639 	u32 accessor_type = function >> 16;
640 	u8 action = function & ACPI_IO_MASK;
641 	acpi_status ret;
642 	int status;
643 
644 	ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
645 	if (ACPI_FAILURE(ret))
646 		return ret;
647 
648 	client = kzalloc(sizeof(*client), GFP_KERNEL);
649 	if (!client) {
650 		ret = AE_NO_MEMORY;
651 		goto err;
652 	}
653 
654 	if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
655 		ret = AE_BAD_PARAMETER;
656 		goto err;
657 	}
658 
659 	client->adapter = adapter;
660 	client->addr = sb->slave_address;
661 
662 	if (sb->access_mode == ACPI_I2C_10BIT_MODE)
663 		client->flags |= I2C_CLIENT_TEN;
664 
665 	switch (accessor_type) {
666 	case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
667 		if (action == ACPI_READ) {
668 			status = i2c_smbus_read_byte(client);
669 			if (status >= 0) {
670 				gsb->bdata = status;
671 				status = 0;
672 			}
673 		} else {
674 			status = i2c_smbus_write_byte(client, gsb->bdata);
675 		}
676 		break;
677 
678 	case ACPI_GSB_ACCESS_ATTRIB_BYTE:
679 		if (action == ACPI_READ) {
680 			status = i2c_smbus_read_byte_data(client, command);
681 			if (status >= 0) {
682 				gsb->bdata = status;
683 				status = 0;
684 			}
685 		} else {
686 			status = i2c_smbus_write_byte_data(client, command,
687 					gsb->bdata);
688 		}
689 		break;
690 
691 	case ACPI_GSB_ACCESS_ATTRIB_WORD:
692 		if (action == ACPI_READ) {
693 			status = i2c_smbus_read_word_data(client, command);
694 			if (status >= 0) {
695 				gsb->wdata = status;
696 				status = 0;
697 			}
698 		} else {
699 			status = i2c_smbus_write_word_data(client, command,
700 					gsb->wdata);
701 		}
702 		break;
703 
704 	case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
705 		if (action == ACPI_READ) {
706 			status = i2c_smbus_read_block_data(client, command,
707 					gsb->data);
708 			if (status >= 0) {
709 				gsb->len = status;
710 				status = 0;
711 			}
712 		} else {
713 			status = i2c_smbus_write_block_data(client, command,
714 					gsb->len, gsb->data);
715 		}
716 		break;
717 
718 	case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
719 		if (action == ACPI_READ) {
720 			status = acpi_gsb_i2c_read_bytes(client, command,
721 					gsb->data, info->access_length);
722 		} else {
723 			status = acpi_gsb_i2c_write_bytes(client, command,
724 					gsb->data, info->access_length);
725 		}
726 		break;
727 
728 	default:
729 		dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
730 			 accessor_type, client->addr);
731 		ret = AE_BAD_PARAMETER;
732 		goto err;
733 	}
734 
735 	gsb->status = status;
736 
737  err:
738 	kfree(client);
739 	ACPI_FREE(ares);
740 	return ret;
741 }
742 
743 
744 int i2c_acpi_install_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 -ENODEV;
752 
753 	handle = ACPI_HANDLE(adapter->dev.parent);
754 
755 	if (!handle)
756 		return -ENODEV;
757 
758 	data = kzalloc(sizeof(struct i2c_acpi_handler_data),
759 			    GFP_KERNEL);
760 	if (!data)
761 		return -ENOMEM;
762 
763 	data->adapter = adapter;
764 	status = acpi_bus_attach_private_data(handle, (void *)data);
765 	if (ACPI_FAILURE(status)) {
766 		kfree(data);
767 		return -ENOMEM;
768 	}
769 
770 	status = acpi_install_address_space_handler(handle,
771 				ACPI_ADR_SPACE_GSBUS,
772 				&i2c_acpi_space_handler,
773 				NULL,
774 				data);
775 	if (ACPI_FAILURE(status)) {
776 		dev_err(&adapter->dev, "Error installing i2c space handler\n");
777 		acpi_bus_detach_private_data(handle);
778 		kfree(data);
779 		return -ENOMEM;
780 	}
781 
782 	return 0;
783 }
784 
785 void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
786 {
787 	acpi_handle handle;
788 	struct i2c_acpi_handler_data *data;
789 	acpi_status status;
790 
791 	if (!adapter->dev.parent)
792 		return;
793 
794 	handle = ACPI_HANDLE(adapter->dev.parent);
795 
796 	if (!handle)
797 		return;
798 
799 	acpi_remove_address_space_handler(handle,
800 				ACPI_ADR_SPACE_GSBUS,
801 				&i2c_acpi_space_handler);
802 
803 	status = acpi_bus_get_private_data(handle, (void **)&data);
804 	if (ACPI_SUCCESS(status))
805 		kfree(data);
806 
807 	acpi_bus_detach_private_data(handle);
808 }
809 #endif /* CONFIG_ACPI_I2C_OPREGION */
810