[linux-2.6-block.git] / drivers / acpi / sbshc.c

/*
 * SMBus driver for ACPI Embedded Controller (v0.1)
 *
 * Copyright (c) 2007 Alexey Starikovskiy
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation version 2.
 */

#include <linux/acpi.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/dmi.h>
#include "sbshc.h"

#define PREFIX "ACPI: "

#define ACPI_SMB_HC_CLASS	"smbus_host_ctl"
#define ACPI_SMB_HC_DEVICE_NAME	"ACPI SMBus HC"

struct acpi_smb_hc {
	struct acpi_ec *ec;
	struct mutex lock;
	wait_queue_head_t wait;
	u8 offset;
	u8 query_bit;
	smbus_alarm_callback callback;
	void *context;
};

static int acpi_smbus_hc_add(struct acpi_device *device);
static int acpi_smbus_hc_remove(struct acpi_device *device);

static const struct acpi_device_id sbs_device_ids[] = {
	{"ACPI0001", 0},
	{"ACPI0005", 0},
	{"", 0},
};

MODULE_DEVICE_TABLE(acpi, sbs_device_ids);

static struct acpi_driver acpi_smb_hc_driver = {
	.name = "smbus_hc",
	.class = ACPI_SMB_HC_CLASS,
	.ids = sbs_device_ids,
	.ops = {
		.add = acpi_smbus_hc_add,
		.remove = acpi_smbus_hc_remove,
		},
};

union acpi_smb_status {
	u8 raw;
	struct {
		u8 status:5;
		u8 reserved:1;
		u8 alarm:1;
		u8 done:1;
	} fields;
};

enum acpi_smb_status_codes {
	SMBUS_OK = 0,
	SMBUS_UNKNOWN_FAILURE = 0x07,
	SMBUS_DEVICE_ADDRESS_NACK = 0x10,
	SMBUS_DEVICE_ERROR = 0x11,
	SMBUS_DEVICE_COMMAND_ACCESS_DENIED = 0x12,
	SMBUS_UNKNOWN_ERROR = 0x13,
	SMBUS_DEVICE_ACCESS_DENIED = 0x17,
	SMBUS_TIMEOUT = 0x18,
	SMBUS_HOST_UNSUPPORTED_PROTOCOL = 0x19,
	SMBUS_BUSY = 0x1a,
	SMBUS_PEC_ERROR = 0x1f,
};

enum acpi_smb_offset {
	ACPI_SMB_PROTOCOL = 0,	/* protocol, PEC */
	ACPI_SMB_STATUS = 1,	/* status */
	ACPI_SMB_ADDRESS = 2,	/* address */
	ACPI_SMB_COMMAND = 3,	/* command */
	ACPI_SMB_DATA = 4,	/* 32 data registers */
	ACPI_SMB_BLOCK_COUNT = 0x24,	/* number of data bytes */
	ACPI_SMB_ALARM_ADDRESS = 0x25,	/* alarm address */
	ACPI_SMB_ALARM_DATA = 0x26,	/* 2 bytes alarm data */
};

static bool macbook;

static inline int smb_hc_read(struct acpi_smb_hc *hc, u8 address, u8 *data)
{
	return ec_read(hc->offset + address, data);
}

static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data)
{
	return ec_write(hc->offset + address, data);
}

static inline int smb_check_done(struct acpi_smb_hc *hc)
{
	union acpi_smb_status status = {.raw = 0};
	smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw);
	return status.fields.done && (status.fields.status == SMBUS_OK);
}

static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout)
{
	if (wait_event_timeout(hc->wait, smb_check_done(hc),
			       msecs_to_jiffies(timeout)))
		return 0;
	/*
	 * After the timeout happens, OS will try to check the status of SMbus.
	 * If the status is what OS expected, it will be regarded as the bogus
	 * timeout.
	 */
	if (smb_check_done(hc))
		return 0;
	else
		return -ETIME;
}

static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
				  u8 address, u8 command, u8 *data, u8 length)
{
	int ret = -EFAULT, i;
	u8 temp, sz = 0;

	if (!hc) {
		printk(KERN_ERR PREFIX "host controller is not configured\n");
		return ret;
	}

	mutex_lock(&hc->lock);
	if (macbook)
		udelay(5);
	if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
		goto end;
	if (temp) {
		ret = -EBUSY;
		goto end;
	}
	smb_hc_write(hc, ACPI_SMB_COMMAND, command);
	if (!(protocol & 0x01)) {
		smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length);
		for (i = 0; i < length; ++i)
			smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]);
	}
	smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
	smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
	/*
	 * Wait for completion. Save the status code, data size,
	 * and data into the return package (if required by the protocol).
	 */
	ret = wait_transaction_complete(hc, 1000);
	if (ret || !(protocol & 0x01))
		goto end;
	switch (protocol) {
	case SMBUS_RECEIVE_BYTE:
	case SMBUS_READ_BYTE:
		sz = 1;
		break;
	case SMBUS_READ_WORD:
		sz = 2;
		break;
	case SMBUS_READ_BLOCK:
		if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) {
			ret = -EFAULT;
			goto end;
		}
		sz &= 0x1f;
		break;
	}
	for (i = 0; i < sz; ++i)
		smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]);
      end:
	mutex_unlock(&hc->lock);
	return ret;
}

int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
		    u8 command, u8 *data)
{
	return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
}

EXPORT_SYMBOL_GPL(acpi_smbus_read);

int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
		     u8 command, u8 *data, u8 length)
{
	return acpi_smbus_transaction(hc, protocol, address, command, data, length);
}

EXPORT_SYMBOL_GPL(acpi_smbus_write);

int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
			         smbus_alarm_callback callback, void *context)
{
	mutex_lock(&hc->lock);
	hc->callback = callback;
	hc->context = context;
	mutex_unlock(&hc->lock);
	return 0;
}

EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);

int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
{
	mutex_lock(&hc->lock);
	hc->callback = NULL;
	hc->context = NULL;
	mutex_unlock(&hc->lock);
	return 0;
}

EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);

static inline void acpi_smbus_callback(void *context)
{
	struct acpi_smb_hc *hc = context;
	if (hc->callback)
		hc->callback(hc->context);
}

static int smbus_alarm(void *context)
{
	struct acpi_smb_hc *hc = context;
	union acpi_smb_status status;
	u8 address;
	if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw))
		return 0;
	/* Check if it is only a completion notify */
	if (status.fields.done)
		wake_up(&hc->wait);
	if (!status.fields.alarm)
		return 0;
	mutex_lock(&hc->lock);
	smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address);
	status.fields.alarm = 0;
	smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
	/* We are only interested in events coming from known devices */
	switch (address >> 1) {
		case ACPI_SBS_CHARGER:
		case ACPI_SBS_MANAGER:
		case ACPI_SBS_BATTERY:
			acpi_os_execute(OSL_NOTIFY_HANDLER,
					acpi_smbus_callback, hc);
		default:;
	}
	mutex_unlock(&hc->lock);
	return 0;
}

typedef int (*acpi_ec_query_func) (void *data);

extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
			      acpi_handle handle, acpi_ec_query_func func,
			      void *data);

static int macbook_dmi_match(const struct dmi_system_id *d)
{
	pr_debug("Detected MacBook, enabling workaround\n");
	macbook = true;
	return 0;
}

static struct dmi_system_id acpi_smbus_dmi_table[] = {
	{ macbook_dmi_match, "Apple MacBook", {
	  DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
	  DMI_MATCH(DMI_PRODUCT_NAME, "MacBook") },
	},
	{ },
};

static int acpi_smbus_hc_add(struct acpi_device *device)
{
	int status;
	unsigned long long val;
	struct acpi_smb_hc *hc;

	dmi_check_system(acpi_smbus_dmi_table);

	if (!device)
		return -EINVAL;

	status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val);
	if (ACPI_FAILURE(status)) {
		printk(KERN_ERR PREFIX "error obtaining _EC.\n");
		return -EIO;
	}

	strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
	strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);

	hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL);
	if (!hc)
		return -ENOMEM;
	mutex_init(&hc->lock);
	init_waitqueue_head(&hc->wait);

	hc->ec = acpi_driver_data(device->parent);
	hc->offset = (val >> 8) & 0xff;
	hc->query_bit = val & 0xff;
	device->driver_data = hc;

	acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc);
	printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n",
		hc->ec, hc->offset, hc->query_bit);

	return 0;
}

extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);

static int acpi_smbus_hc_remove(struct acpi_device *device)
{
	struct acpi_smb_hc *hc;

	if (!device)
		return -EINVAL;

	hc = acpi_driver_data(device);
	acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
	kfree(hc);
	device->driver_data = NULL;
	return 0;
}

module_acpi_driver(acpi_smb_hc_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alexey Starikovskiy");
MODULE_DESCRIPTION("ACPI SMBus HC driver");
Commit	Line	Data
91087dfa AS	1	/*
	2	* SMBus driver for ACPI Embedded Controller (v0.1)
	3	*
	4	* Copyright (c) 2007 Alexey Starikovskiy
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation version 2.
	9	*/
	10
8b48463f	11	#include <linux/acpi.h>
91087dfa	12	#include <linux/wait.h>
5a0e3ad6	13	#include <linux/slab.h>
91087dfa	14	#include <linux/delay.h>
cc4b859c	15	#include <linux/module.h>
91087dfa	16	#include <linux/interrupt.h>
3349fb64	17	#include <linux/dmi.h>
91087dfa AS	18	#include "sbshc.h"
91087dfa AS	19
a192a958 LB	20	#define PREFIX "ACPI: "
a192a958 LB	21
97c227cb	22	#define ACPI_SMB_HC_CLASS "smbus_host_ctl"
91087dfa AS	23	#define ACPI_SMB_HC_DEVICE_NAME "ACPI SMBus HC"
	24
	25	struct acpi_smb_hc {
	26	struct acpi_ec *ec;
	27	struct mutex lock;
	28	wait_queue_head_t wait;
	29	u8 offset;
	30	u8 query_bit;
	31	smbus_alarm_callback callback;
	32	void *context;
	33	};
	34
	35	static int acpi_smbus_hc_add(struct acpi_device *device);
51fac838	36	static int acpi_smbus_hc_remove(struct acpi_device *device);
91087dfa AS	37
	38	static const struct acpi_device_id sbs_device_ids[] = {
	39	{"ACPI0001", 0},
	40	{"ACPI0005", 0},
	41	{"", 0},
	42	};
	43
	44	MODULE_DEVICE_TABLE(acpi, sbs_device_ids);
	45
	46	static struct acpi_driver acpi_smb_hc_driver = {
	47	.name = "smbus_hc",
	48	.class = ACPI_SMB_HC_CLASS,
	49	.ids = sbs_device_ids,
	50	.ops = {
	51	.add = acpi_smbus_hc_add,
	52	.remove = acpi_smbus_hc_remove,
	53	},
	54	};
	55
	56	union acpi_smb_status {
	57	u8 raw;
	58	struct {
	59	u8 status:5;
	60	u8 reserved:1;
	61	u8 alarm:1;
	62	u8 done:1;
	63	} fields;
	64	};
	65
	66	enum acpi_smb_status_codes {
	67	SMBUS_OK = 0,
	68	SMBUS_UNKNOWN_FAILURE = 0x07,
	69	SMBUS_DEVICE_ADDRESS_NACK = 0x10,
	70	SMBUS_DEVICE_ERROR = 0x11,
	71	SMBUS_DEVICE_COMMAND_ACCESS_DENIED = 0x12,
	72	SMBUS_UNKNOWN_ERROR = 0x13,
	73	SMBUS_DEVICE_ACCESS_DENIED = 0x17,
	74	SMBUS_TIMEOUT = 0x18,
	75	SMBUS_HOST_UNSUPPORTED_PROTOCOL = 0x19,
	76	SMBUS_BUSY = 0x1a,
	77	SMBUS_PEC_ERROR = 0x1f,
	78	};
	79
	80	enum acpi_smb_offset {
	81	ACPI_SMB_PROTOCOL = 0, /* protocol, PEC */
	82	ACPI_SMB_STATUS = 1, /* status */
	83	ACPI_SMB_ADDRESS = 2, /* address */
	84	ACPI_SMB_COMMAND = 3, /* command */
	85	ACPI_SMB_DATA = 4, /* 32 data registers */
	86	ACPI_SMB_BLOCK_COUNT = 0x24, /* number of data bytes */
	87	ACPI_SMB_ALARM_ADDRESS = 0x25, /* alarm address */
	88	ACPI_SMB_ALARM_DATA = 0x26, /* 2 bytes alarm data */
	89	};
	90
3349fb64 CB	91	static bool macbook;
3349fb64 CB	92
91087dfa AS	93	static inline int smb_hc_read(struct acpi_smb_hc hc, u8 address, u8 data)
	94	{
	95	return ec_read(hc->offset + address, data);
	96	}
	97
	98	static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data)
	99	{
	100	return ec_write(hc->offset + address, data);
	101	}
	102
	103	static inline int smb_check_done(struct acpi_smb_hc *hc)
	104	{
	105	union acpi_smb_status status = {.raw = 0};
	106	smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw);
	107	return status.fields.done && (status.fields.status == SMBUS_OK);
	108	}
	109
	110	static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout)
	111	{
	112	if (wait_event_timeout(hc->wait, smb_check_done(hc),
	113	msecs_to_jiffies(timeout)))
	114	return 0;
266feefe ZY	115	/*
	116	* After the timeout happens, OS will try to check the status of SMbus.
	117	* If the status is what OS expected, it will be regarded as the bogus
	118	* timeout.
	119	*/
	120	if (smb_check_done(hc))
	121	return 0;
91087dfa AS	122	else
	123	return -ETIME;
	124	}
	125
e5685b9d AB	126	static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
e5685b9d AB	127	u8 address, u8 command, u8 *data, u8 length)
91087dfa AS	128	{
	129	int ret = -EFAULT, i;
	130	u8 temp, sz = 0;
	131
bbafbecb AS	132	if (!hc) {
	133	printk(KERN_ERR PREFIX "host controller is not configured\n");
	134	return ret;
	135	}
	136
91087dfa	137	mutex_lock(&hc->lock);
3349fb64 CB	138	if (macbook)
3349fb64 CB	139	udelay(5);
91087dfa AS	140	if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
	141	goto end;
	142	if (temp) {
	143	ret = -EBUSY;
	144	goto end;
	145	}
	146	smb_hc_write(hc, ACPI_SMB_COMMAND, command);
91087dfa AS	147	if (!(protocol & 0x01)) {
	148	smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length);
	149	for (i = 0; i < length; ++i)
	150	smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]);
	151	}
	152	smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
	153	smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
	154	/*
	155	* Wait for completion. Save the status code, data size,
	156	* and data into the return package (if required by the protocol).
	157	*/
	158	ret = wait_transaction_complete(hc, 1000);
	159	if (ret \|\| !(protocol & 0x01))
	160	goto end;
	161	switch (protocol) {
	162	case SMBUS_RECEIVE_BYTE:
	163	case SMBUS_READ_BYTE:
	164	sz = 1;
	165	break;
	166	case SMBUS_READ_WORD:
	167	sz = 2;
	168	break;
	169	case SMBUS_READ_BLOCK:
	170	if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) {
	171	ret = -EFAULT;
	172	goto end;
	173	}
	174	sz &= 0x1f;
	175	break;
	176	}
	177	for (i = 0; i < sz; ++i)
	178	smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]);
	179	end:
	180	mutex_unlock(&hc->lock);
	181	return ret;
	182	}
	183
	184	int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
	185	u8 command, u8 *data)
	186	{
	187	return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
	188	}
	189
	190	EXPORT_SYMBOL_GPL(acpi_smbus_read);
	191
	192	int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
	193	u8 command, u8 *data, u8 length)
	194	{
	195	return acpi_smbus_transaction(hc, protocol, address, command, data, length);
	196	}
	197
	198	EXPORT_SYMBOL_GPL(acpi_smbus_write);
	199
	200	int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
	201	smbus_alarm_callback callback, void *context)
	202	{
	203	mutex_lock(&hc->lock);
	204	hc->callback = callback;
	205	hc->context = context;
	206	mutex_unlock(&hc->lock);
	207	return 0;
	208	}
	209
	210	EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);
211
212	int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
213	{
214	mutex_lock(&hc->lock);
215	hc->callback = NULL;
216	hc->context = NULL;
217	mutex_unlock(&hc->lock);
218	return 0;
219	}
220
221	EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);
222
c2d00f2d	223	static inline void acpi_smbus_callback(void *context)
91087dfa AS	224	{
91087dfa AS	225	struct acpi_smb_hc *hc = context;
91087dfa AS	226	if (hc->callback)
	227	hc->callback(hc->context);
	228	}
	229
	230	static int smbus_alarm(void *context)
	231	{
	232	struct acpi_smb_hc *hc = context;
	233	union acpi_smb_status status;
c2d00f2d	234	u8 address;
91087dfa AS	235	if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw))
	236	return 0;
	237	/* Check if it is only a completion notify */
	238	if (status.fields.done)
	239	wake_up(&hc->wait);
	240	if (!status.fields.alarm)
	241	return 0;
	242	mutex_lock(&hc->lock);
c2d00f2d	243	smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address);
09f1fb41	244	status.fields.alarm = 0;
91087dfa	245	smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
c2d00f2d AS	246	/* We are only interested in events coming from known devices */
	247	switch (address >> 1) {
	248	case ACPI_SBS_CHARGER:
	249	case ACPI_SBS_MANAGER:
	250	case ACPI_SBS_BATTERY:
f5347867	251	acpi_os_execute(OSL_NOTIFY_HANDLER,
c2d00f2d AS	252	acpi_smbus_callback, hc);
	253	default:;
	254	}
91087dfa AS	255	mutex_unlock(&hc->lock);
	256	return 0;
	257	}
	258
	259	typedef int (acpi_ec_query_func) (void data);
	260
	261	extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
	262	acpi_handle handle, acpi_ec_query_func func,
	263	void *data);
	264
3349fb64 CB	265	static int macbook_dmi_match(const struct dmi_system_id *d)
	266	{
	267	pr_debug("Detected MacBook, enabling workaround\n");
	268	macbook = true;
	269	return 0;
	270	}
	271
	272	static struct dmi_system_id acpi_smbus_dmi_table[] = {
	273	{ macbook_dmi_match, "Apple MacBook", {
	274	DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
	275	DMI_MATCH(DMI_PRODUCT_NAME, "MacBook") },
	276	},
	277	{ },
	278	};
	279
91087dfa AS	280	static int acpi_smbus_hc_add(struct acpi_device *device)
	281	{
	282	int status;
27663c58	283	unsigned long long val;
91087dfa AS	284	struct acpi_smb_hc *hc;
91087dfa AS	285
3349fb64 CB	286	dmi_check_system(acpi_smbus_dmi_table);
3349fb64 CB	287
91087dfa AS	288	if (!device)
	289	return -EINVAL;
	290
	291	status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val);
	292	if (ACPI_FAILURE(status)) {
	293	printk(KERN_ERR PREFIX "error obtaining _EC.\n");
	294	return -EIO;
	295	}
	296
	297	strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
	298	strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
	299
	300	hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL);
	301	if (!hc)
	302	return -ENOMEM;
	303	mutex_init(&hc->lock);
	304	init_waitqueue_head(&hc->wait);
	305
	306	hc->ec = acpi_driver_data(device->parent);
	307	hc->offset = (val >> 8) & 0xff;
	308	hc->query_bit = val & 0xff;
db89b4f0	309	device->driver_data = hc;
91087dfa AS	310
	311	acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc);
	312	printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n",
	313	hc->ec, hc->offset, hc->query_bit);
	314
	315	return 0;
	316	}
	317
	318	extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
	319
51fac838	320	static int acpi_smbus_hc_remove(struct acpi_device *device)
91087dfa AS	321	{
	322	struct acpi_smb_hc *hc;
	323
	324	if (!device)
	325	return -EINVAL;
	326
	327	hc = acpi_driver_data(device);
	328	acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
	329	kfree(hc);
db89b4f0	330	device->driver_data = NULL;
91087dfa AS	331	return 0;
	332	}
	333
e84a239e	334	module_acpi_driver(acpi_smb_hc_driver);
91087dfa AS	335
	336	MODULE_LICENSE("GPL");
	337	MODULE_AUTHOR("Alexey Starikovskiy");
	338	MODULE_DESCRIPTION("ACPI SMBus HC driver");