drivers/platform/x86/panasonic-laptop.c - arm/linux-arm-legacy - Git at Google

 /*
  *  Panasonic HotKey and LCD brightness control driver
  *  (C) 2004 Hiroshi Miura <miura@da-cha.org>
  *  (C) 2004 NTT DATA Intellilink Co. http://www.intellilink.co.jp/
  *  (C) YOKOTA Hiroshi <yokota (at) netlab. is. tsukuba. ac. jp>
  *  (C) 2004 David Bronaugh <dbronaugh>
  *  (C) 2006-2008 Harald Welte <laforge@gnumonks.org>
  *
  *  derived from toshiba_acpi.c, Copyright (C) 2002-2004 John Belmonte
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2 as
  *  publicshed by the Free Software Foundation.
  *
  *  This program is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
  *
  *---------------------------------------------------------------------------
  *
  * ChangeLog:
  *	Sep.23, 2008	Harald Welte <laforge@gnumonks.org>
  *		-v0.95	rename driver from drivers/acpi/pcc_acpi.c to
  *			drivers/misc/panasonic-laptop.c
  *
  * 	Jul.04, 2008	Harald Welte <laforge@gnumonks.org>
  * 		-v0.94	replace /proc interface with device attributes
  * 			support {set,get}keycode on th input device
  *
  *      Jun.27, 2008	Harald Welte <laforge@gnumonks.org>
  *      	-v0.92	merge with 2.6.26-rc6 input API changes
  *      		remove broken <= 2.6.15 kernel support
  *      		resolve all compiler warnings
  *      		various coding style fixes (checkpatch.pl)
  *      		add support for backlight api
  *      		major code restructuring
  *
  * 	Dac.28, 2007	Harald Welte <laforge@gnumonks.org>
  * 		-v0.91	merge with 2.6.24-rc6 ACPI changes
  *
  * 	Nov.04, 2006	Hiroshi Miura <miura@da-cha.org>
  * 		-v0.9	remove warning about section reference.
  * 			remove acpi_os_free
  * 			add /proc/acpi/pcc/brightness interface for HAL access
  * 			merge dbronaugh's enhancement
  * 			Aug.17, 2004 David Bronaugh (dbronaugh)
  *  				- Added screen brightness setting interface
  *				  Thanks to FreeBSD crew (acpi_panasonic.c)
  * 				  for the ideas I needed to accomplish it
  *
  *	May.29, 2006	Hiroshi Miura <miura@da-cha.org>
  *		-v0.8.4 follow to change keyinput structure
  *			thanks Fabian Yamaguchi <fabs@cs.tu-berlin.de>,
  *			Jacob Bower <jacob.bower@ic.ac.uk> and
  *			Hiroshi Yokota for providing solutions.
  *
  *	Oct.02, 2004	Hiroshi Miura <miura@da-cha.org>
  *		-v0.8.2	merge code of YOKOTA Hiroshi
  *					<yokota@netlab.is.tsukuba.ac.jp>.
  *			Add sticky key mode interface.
  *			Refactoring acpi_pcc_generate_keyinput().
  *
  *	Sep.15, 2004	Hiroshi Miura <miura@da-cha.org>
  *		-v0.8	Generate key input event on input subsystem.
  *			This is based on yet another driver written by
  *							Ryuta Nakanishi.
  *
  *	Sep.10, 2004	Hiroshi Miura <miura@da-cha.org>
  *		-v0.7	Change proc interface functions using seq_file
  *			facility as same as other ACPI drivers.
  *
  *	Aug.28, 2004	Hiroshi Miura <miura@da-cha.org>
  *		-v0.6.4 Fix a silly error with status checking
  *
  *	Aug.25, 2004	Hiroshi Miura <miura@da-cha.org>
  *		-v0.6.3 replace read_acpi_int by standard function
  *							acpi_evaluate_integer
  *			some clean up and make smart copyright notice.
  *			fix return value of pcc_acpi_get_key()
  *			fix checking return value of acpi_bus_register_driver()
  *
  *      Aug.22, 2004    David Bronaugh <dbronaugh@linuxboxen.org>
  *              -v0.6.2 Add check on ACPI data (num_sifr)
  *                      Coding style cleanups, better error messages/handling
  *			Fixed an off-by-one error in memory allocation
  *
  *      Aug.21, 2004    David Bronaugh <dbronaugh@linuxboxen.org>
  *              -v0.6.1 Fix a silly error with status checking
  *
  *      Aug.20, 2004    David Bronaugh <dbronaugh@linuxboxen.org>
  *              - v0.6  Correct brightness controls to reflect reality
  *                      based on information gleaned by Hiroshi Miura
  *                      and discussions with Hiroshi Miura
  *
  *	Aug.10, 2004	Hiroshi Miura <miura@da-cha.org>
  *		- v0.5  support LCD brightness control
  *			based on the disclosed information by MEI.
  *
  *	Jul.25, 2004	Hiroshi Miura <miura@da-cha.org>
  *		- v0.4  first post version
  *		        add function to retrive SIFR
  *
  *	Jul.24, 2004	Hiroshi Miura <miura@da-cha.org>
  *		- v0.3  get proper status of hotkey
  *
  *      Jul.22, 2004	Hiroshi Miura <miura@da-cha.org>
  *		- v0.2  add HotKey handler
  *
  *      Jul.17, 2004	Hiroshi Miura <miura@da-cha.org>
  *		- v0.1  start from toshiba_acpi driver written by John Belmonte
  *
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/backlight.h>
 #include <linux/ctype.h>
 #include <linux/seq_file.h>
 #include <linux/uaccess.h>
 #include <linux/slab.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>
 #include <linux/input.h>
 #include <linux/input/sparse-keymap.h>


 #ifndef ACPI_HOTKEY_COMPONENT
 #define ACPI_HOTKEY_COMPONENT	0x10000000
 #endif

 #define _COMPONENT		ACPI_HOTKEY_COMPONENT

 MODULE_AUTHOR("Hiroshi Miura, David Bronaugh and Harald Welte");
 MODULE_DESCRIPTION("ACPI HotKey driver for Panasonic Let's Note laptops");
 MODULE_LICENSE("GPL");

 #define LOGPREFIX "pcc_acpi: "

 /* Define ACPI PATHs */
 /* Lets note hotkeys */
 #define METHOD_HKEY_QUERY	"HINF"
 #define METHOD_HKEY_SQTY	"SQTY"
 #define METHOD_HKEY_SINF	"SINF"
 #define METHOD_HKEY_SSET	"SSET"
 #define HKEY_NOTIFY		 0x80

 #define ACPI_PCC_DRIVER_NAME	"Panasonic Laptop Support"
 #define ACPI_PCC_DEVICE_NAME	"Hotkey"
 #define ACPI_PCC_CLASS		"pcc"

 #define ACPI_PCC_INPUT_PHYS	"panasonic/hkey0"

 /* LCD_TYPEs: 0 = Normal, 1 = Semi-transparent
    ENV_STATEs: Normal temp=0x01, High temp=0x81, N/A=0x00
 */
 enum SINF_BITS { SINF_NUM_BATTERIES = 0,
 		 SINF_LCD_TYPE,
 		 SINF_AC_MAX_BRIGHT,
 		 SINF_AC_MIN_BRIGHT,
 		 SINF_AC_CUR_BRIGHT,
 		 SINF_DC_MAX_BRIGHT,
 		 SINF_DC_MIN_BRIGHT,
 		 SINF_DC_CUR_BRIGHT,
 		 SINF_MUTE,
 		 SINF_RESERVED,
 		 SINF_ENV_STATE,
 		 SINF_STICKY_KEY = 0x80,
 	};
 /* R1 handles SINF_AC_CUR_BRIGHT as SINF_CUR_BRIGHT, doesn't know AC state */

 static int acpi_pcc_hotkey_add(struct acpi_device *device);
 static int acpi_pcc_hotkey_remove(struct acpi_device *device);
 static void acpi_pcc_hotkey_notify(struct acpi_device *device, u32 event);

 static const struct acpi_device_id pcc_device_ids[] = {
 	{ "MAT0012", 0},
 	{ "MAT0013", 0},
 	{ "MAT0018", 0},
 	{ "MAT0019", 0},
 	{ "", 0},
 };
 MODULE_DEVICE_TABLE(acpi, pcc_device_ids);

 #ifdef CONFIG_PM_SLEEP
 static int acpi_pcc_hotkey_resume(struct device *dev);
 #endif
 static SIMPLE_DEV_PM_OPS(acpi_pcc_hotkey_pm, NULL, acpi_pcc_hotkey_resume);

 static struct acpi_driver acpi_pcc_driver = {
 	.name =		ACPI_PCC_DRIVER_NAME,
 	.class =	ACPI_PCC_CLASS,
 	.ids =		pcc_device_ids,
 	.ops =		{
 				.add =		acpi_pcc_hotkey_add,
 				.remove =	acpi_pcc_hotkey_remove,
 				.notify =	acpi_pcc_hotkey_notify,
 			},
 	.drv.pm =	&acpi_pcc_hotkey_pm,
 };

 static const struct key_entry panasonic_keymap[] = {
 	{ KE_KEY, 0, { KEY_RESERVED } },
 	{ KE_KEY, 1, { KEY_BRIGHTNESSDOWN } },
 	{ KE_KEY, 2, { KEY_BRIGHTNESSUP } },
 	{ KE_KEY, 3, { KEY_DISPLAYTOGGLE } },
 	{ KE_KEY, 4, { KEY_MUTE } },
 	{ KE_KEY, 5, { KEY_VOLUMEDOWN } },
 	{ KE_KEY, 6, { KEY_VOLUMEUP } },
 	{ KE_KEY, 7, { KEY_SLEEP } },
 	{ KE_KEY, 8, { KEY_PROG1 } }, /* Change CPU boost */
 	{ KE_KEY, 9, { KEY_BATTERY } },
 	{ KE_KEY, 10, { KEY_SUSPEND } },
 	{ KE_END, 0 }
 };

 struct pcc_acpi {
 	acpi_handle		handle;
 	unsigned long		num_sifr;
 	int			sticky_mode;
 	u32			*sinf;
 	struct acpi_device	*device;
 	struct input_dev	*input_dev;
 	struct backlight_device	*backlight;
 };

 struct pcc_keyinput {
 	struct acpi_hotkey      *hotkey;
 };

 /* method access functions */
 static int acpi_pcc_write_sset(struct pcc_acpi *pcc, int func, int val)
 {
 	union acpi_object in_objs[] = {
 		{ .integer.type  = ACPI_TYPE_INTEGER,
 		  .integer.value = func, },
 		{ .integer.type  = ACPI_TYPE_INTEGER,
 		  .integer.value = val, },
 	};
 	struct acpi_object_list params = {
 		.count   = ARRAY_SIZE(in_objs),
 		.pointer = in_objs,
 	};
 	acpi_status status = AE_OK;

 	status = acpi_evaluate_object(pcc->handle, METHOD_HKEY_SSET,
 				      &params, NULL);

 	return (status == AE_OK) ? 0 : -EIO;
 }

 static inline int acpi_pcc_get_sqty(struct acpi_device *device)
 {
 	unsigned long long s;
 	acpi_status status;

 	status = acpi_evaluate_integer(device->handle, METHOD_HKEY_SQTY,
 				       NULL, &s);
 	if (ACPI_SUCCESS(status))
 		return s;
 	else {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 				  "evaluation error HKEY.SQTY\n"));
 		return -EINVAL;
 	}
 }

 static int acpi_pcc_retrieve_biosdata(struct pcc_acpi *pcc)
 {
 	acpi_status status;
 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 	union acpi_object *hkey = NULL;
 	int i;

 	status = acpi_evaluate_object(pcc->handle, METHOD_HKEY_SINF, NULL,
 				      &buffer);
 	if (ACPI_FAILURE(status)) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 				  "evaluation error HKEY.SINF\n"));
 		return 0;
 	}

 	hkey = buffer.pointer;
 	if (!hkey || (hkey->type != ACPI_TYPE_PACKAGE)) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid HKEY.SINF\n"));
 		status = AE_ERROR;
 		goto end;
 	}

 	if (pcc->num_sifr < hkey->package.count) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 				 "SQTY reports bad SINF length\n"));
 		status = AE_ERROR;
 		goto end;
 	}

 	for (i = 0; i < hkey->package.count; i++) {
 		union acpi_object *element = &(hkey->package.elements[i]);
 		if (likely(element->type == ACPI_TYPE_INTEGER)) {
 			pcc->sinf[i] = element->integer.value;
 		} else
 			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 					 "Invalid HKEY.SINF data\n"));
 	}
 	pcc->sinf[hkey->package.count] = -1;

 end:
 	kfree(buffer.pointer);
 	return status == AE_OK;
 }

 /* backlight API interface functions */

 /* This driver currently treats AC and DC brightness identical,
  * since we don't need to invent an interface to the core ACPI
  * logic to receive events in case a power supply is plugged in
  * or removed */

 static int bl_get(struct backlight_device *bd)
 {
 	struct pcc_acpi *pcc = bl_get_data(bd);

 	if (!acpi_pcc_retrieve_biosdata(pcc))
 		return -EIO;

 	return pcc->sinf[SINF_AC_CUR_BRIGHT];
 }

 static int bl_set_status(struct backlight_device *bd)
 {
 	struct pcc_acpi *pcc = bl_get_data(bd);
 	int bright = bd->props.brightness;
 	int rc;

 	if (!acpi_pcc_retrieve_biosdata(pcc))
 		return -EIO;

 	if (bright < pcc->sinf[SINF_AC_MIN_BRIGHT])
 		bright = pcc->sinf[SINF_AC_MIN_BRIGHT];

 	if (bright < pcc->sinf[SINF_DC_MIN_BRIGHT])
 		bright = pcc->sinf[SINF_DC_MIN_BRIGHT];

 	if (bright < pcc->sinf[SINF_AC_MIN_BRIGHT] ||
 	    bright > pcc->sinf[SINF_AC_MAX_BRIGHT])
 		return -EINVAL;

 	rc = acpi_pcc_write_sset(pcc, SINF_AC_CUR_BRIGHT, bright);
 	if (rc < 0)
 		return rc;

 	return acpi_pcc_write_sset(pcc, SINF_DC_CUR_BRIGHT, bright);
 }

 static const struct backlight_ops pcc_backlight_ops = {
 	.get_brightness	= bl_get,
 	.update_status	= bl_set_status,
 };


 /* sysfs user interface functions */

 static ssize_t show_numbatt(struct device *dev, struct device_attribute *attr,
 			    char *buf)
 {
 	struct acpi_device *acpi = to_acpi_device(dev);
 	struct pcc_acpi *pcc = acpi_driver_data(acpi);

 	if (!acpi_pcc_retrieve_biosdata(pcc))
 		return -EIO;

 	return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_NUM_BATTERIES]);
 }

 static ssize_t show_lcdtype(struct device *dev, struct device_attribute *attr,
 			    char *buf)
 {
 	struct acpi_device *acpi = to_acpi_device(dev);
 	struct pcc_acpi *pcc = acpi_driver_data(acpi);

 	if (!acpi_pcc_retrieve_biosdata(pcc))
 		return -EIO;

 	return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_LCD_TYPE]);
 }

 static ssize_t show_mute(struct device *dev, struct device_attribute *attr,
 			 char *buf)
 {
 	struct acpi_device *acpi = to_acpi_device(dev);
 	struct pcc_acpi *pcc = acpi_driver_data(acpi);

 	if (!acpi_pcc_retrieve_biosdata(pcc))
 		return -EIO;

 	return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_MUTE]);
 }

 static ssize_t show_sticky(struct device *dev, struct device_attribute *attr,
 			   char *buf)
 {
 	struct acpi_device *acpi = to_acpi_device(dev);
 	struct pcc_acpi *pcc = acpi_driver_data(acpi);

 	if (!acpi_pcc_retrieve_biosdata(pcc))
 		return -EIO;

 	return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_STICKY_KEY]);
 }

 static ssize_t set_sticky(struct device *dev, struct device_attribute *attr,
 			  const char *buf, size_t count)
 {
 	struct acpi_device *acpi = to_acpi_device(dev);
 	struct pcc_acpi *pcc = acpi_driver_data(acpi);
 	int val;

 	if (count && sscanf(buf, "%i", &val) == 1 &&
 	    (val == 0 || val == 1)) {
 		acpi_pcc_write_sset(pcc, SINF_STICKY_KEY, val);
 		pcc->sticky_mode = val;
 	}

 	return count;
 }

 static DEVICE_ATTR(numbatt, S_IRUGO, show_numbatt, NULL);
 static DEVICE_ATTR(lcdtype, S_IRUGO, show_lcdtype, NULL);
 static DEVICE_ATTR(mute, S_IRUGO, show_mute, NULL);
 static DEVICE_ATTR(sticky_key, S_IRUGO | S_IWUSR, show_sticky, set_sticky);

 static struct attribute *pcc_sysfs_entries[] = {
 	&dev_attr_numbatt.attr,
 	&dev_attr_lcdtype.attr,
 	&dev_attr_mute.attr,
 	&dev_attr_sticky_key.attr,
 	NULL,
 };

 static struct attribute_group pcc_attr_group = {
 	.name	= NULL,		/* put in device directory */
 	.attrs	= pcc_sysfs_entries,
 };


 /* hotkey input device driver */

 static void acpi_pcc_generate_keyinput(struct pcc_acpi *pcc)
 {
 	struct input_dev *hotk_input_dev = pcc->input_dev;
 	int rc;
 	unsigned long long result;

 	rc = acpi_evaluate_integer(pcc->handle, METHOD_HKEY_QUERY,
 				   NULL, &result);
 	if (!ACPI_SUCCESS(rc)) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 				 "error getting hotkey status\n"));
 		return;
 	}
 	if (!sparse_keymap_report_event(hotk_input_dev,
 					result & 0xf, result & 0x80, false))
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 				  "Unknown hotkey event: %d\n", result));
 }

 static void acpi_pcc_hotkey_notify(struct acpi_device *device, u32 event)
 {
 	struct pcc_acpi *pcc = acpi_driver_data(device);

 	switch (event) {
 	case HKEY_NOTIFY:
 		acpi_pcc_generate_keyinput(pcc);
 		break;
 	default:
 		/* nothing to do */
 		break;
 	}
 }

 static int acpi_pcc_init_input(struct pcc_acpi *pcc)
 {
 	struct input_dev *input_dev;
 	int error;

 	input_dev = input_allocate_device();
 	if (!input_dev) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 				  "Couldn't allocate input device for hotkey"));
 		return -ENOMEM;
 	}

 	input_dev->name = ACPI_PCC_DRIVER_NAME;
 	input_dev->phys = ACPI_PCC_INPUT_PHYS;
 	input_dev->id.bustype = BUS_HOST;
 	input_dev->id.vendor = 0x0001;
 	input_dev->id.product = 0x0001;
 	input_dev->id.version = 0x0100;

 	error = sparse_keymap_setup(input_dev, panasonic_keymap, NULL);
 	if (error) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 				  "Unable to setup input device keymap\n"));
 		goto err_free_dev;
 	}

 	error = input_register_device(input_dev);
 	if (error) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 				  "Unable to register input device\n"));
 		goto err_free_keymap;
 	}

 	pcc->input_dev = input_dev;
 	return 0;

  err_free_keymap:
 	sparse_keymap_free(input_dev);
  err_free_dev:
 	input_free_device(input_dev);
 	return error;
 }

 static void acpi_pcc_destroy_input(struct pcc_acpi *pcc)
 {
 	sparse_keymap_free(pcc->input_dev);
 	input_unregister_device(pcc->input_dev);
 	/*
 	 * No need to input_free_device() since core input API refcounts
 	 * and free()s the device.
 	 */
 }

 /* kernel module interface */

 #ifdef CONFIG_PM_SLEEP
 static int acpi_pcc_hotkey_resume(struct device *dev)
 {
 	struct pcc_acpi *pcc;

 	if (!dev)
 		return -EINVAL;

 	pcc = acpi_driver_data(to_acpi_device(dev));
 	if (!pcc)
 		return -EINVAL;

 	ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Sticky mode restore: %d\n",
 			  pcc->sticky_mode));

 	return acpi_pcc_write_sset(pcc, SINF_STICKY_KEY, pcc->sticky_mode);
 }
 #endif

 static int acpi_pcc_hotkey_add(struct acpi_device *device)
 {
 	struct backlight_properties props;
 	struct pcc_acpi *pcc;
 	int num_sifr, result;

 	if (!device)
 		return -EINVAL;

 	num_sifr = acpi_pcc_get_sqty(device);

 	if (num_sifr < 0 || num_sifr > 255) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "num_sifr out of range"));
 		return -ENODEV;
 	}

 	pcc = kzalloc(sizeof(struct pcc_acpi), GFP_KERNEL);
 	if (!pcc) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 				  "Couldn't allocate mem for pcc"));
 		return -ENOMEM;
 	}

 	pcc->sinf = kzalloc(sizeof(u32) * (num_sifr + 1), GFP_KERNEL);
 	if (!pcc->sinf) {
 		result = -ENOMEM;
 		goto out_hotkey;
 	}

 	pcc->device = device;
 	pcc->handle = device->handle;
 	pcc->num_sifr = num_sifr;
 	device->driver_data = pcc;
 	strcpy(acpi_device_name(device), ACPI_PCC_DEVICE_NAME);
 	strcpy(acpi_device_class(device), ACPI_PCC_CLASS);

 	result = acpi_pcc_init_input(pcc);
 	if (result) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 				  "Error installing keyinput handler\n"));
 		goto out_sinf;
 	}

 	if (!acpi_pcc_retrieve_biosdata(pcc)) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 				 "Couldn't retrieve BIOS data\n"));
 		result = -EIO;
 		goto out_input;
 	}
 	/* initialize backlight */
 	memset(&props, 0, sizeof(struct backlight_properties));
 	props.type = BACKLIGHT_PLATFORM;
 	props.max_brightness = pcc->sinf[SINF_AC_MAX_BRIGHT];
 	pcc->backlight = backlight_device_register("panasonic", NULL, pcc,
 						   &pcc_backlight_ops, &props);
 	if (IS_ERR(pcc->backlight)) {
 		result = PTR_ERR(pcc->backlight);
 		goto out_input;
 	}

 	/* read the initial brightness setting from the hardware */
 	pcc->backlight->props.brightness = pcc->sinf[SINF_AC_CUR_BRIGHT];

 	/* read the initial sticky key mode from the hardware */
 	pcc->sticky_mode = pcc->sinf[SINF_STICKY_KEY];

 	/* add sysfs attributes */
 	result = sysfs_create_group(&device->dev.kobj, &pcc_attr_group);
 	if (result)
 		goto out_backlight;

 	return 0;

 out_backlight:
 	backlight_device_unregister(pcc->backlight);
 out_input:
 	acpi_pcc_destroy_input(pcc);
 out_sinf:
 	kfree(pcc->sinf);
 out_hotkey:
 	kfree(pcc);

 	return result;
 }

 static int acpi_pcc_hotkey_remove(struct acpi_device *device)
 {
 	struct pcc_acpi *pcc = acpi_driver_data(device);

 	if (!device || !pcc)
 		return -EINVAL;

 	sysfs_remove_group(&device->dev.kobj, &pcc_attr_group);

 	backlight_device_unregister(pcc->backlight);

 	acpi_pcc_destroy_input(pcc);

 	kfree(pcc->sinf);
 	kfree(pcc);

 	return 0;
 }

 module_acpi_driver(acpi_pcc_driver);
	/*
	* Panasonic HotKey and LCD brightness control driver
	* (C) 2004 Hiroshi Miura <miura@da-cha.org>
	* (C) 2004 NTT DATA Intellilink Co. http://www.intellilink.co.jp/
	* (C) YOKOTA Hiroshi <yokota (at) netlab. is. tsukuba. ac. jp>
	* (C) 2004 David Bronaugh <dbronaugh>
	* (C) 2006-2008 Harald Welte <laforge@gnumonks.org>
	*
	* derived from toshiba_acpi.c, Copyright (C) 2002-2004 John Belmonte
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* publicshed by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	*---------------------------------------------------------------------------
	*
	* ChangeLog:
	* Sep.23, 2008 Harald Welte <laforge@gnumonks.org>
	* -v0.95 rename driver from drivers/acpi/pcc_acpi.c to
	* drivers/misc/panasonic-laptop.c
	*
	* Jul.04, 2008 Harald Welte <laforge@gnumonks.org>
	* -v0.94 replace /proc interface with device attributes
	* support {set,get}keycode on th input device
	*
	* Jun.27, 2008 Harald Welte <laforge@gnumonks.org>
	* -v0.92 merge with 2.6.26-rc6 input API changes
	* remove broken <= 2.6.15 kernel support
	* resolve all compiler warnings
	* various coding style fixes (checkpatch.pl)
	* add support for backlight api
	* major code restructuring
	*
	* Dac.28, 2007 Harald Welte <laforge@gnumonks.org>
	* -v0.91 merge with 2.6.24-rc6 ACPI changes
	*
	* Nov.04, 2006 Hiroshi Miura <miura@da-cha.org>
	* -v0.9 remove warning about section reference.
	* remove acpi_os_free
	* add /proc/acpi/pcc/brightness interface for HAL access
	* merge dbronaugh's enhancement
	* Aug.17, 2004 David Bronaugh (dbronaugh)
	* - Added screen brightness setting interface
	* Thanks to FreeBSD crew (acpi_panasonic.c)
	* for the ideas I needed to accomplish it
	*
	* May.29, 2006 Hiroshi Miura <miura@da-cha.org>
	* -v0.8.4 follow to change keyinput structure
	* thanks Fabian Yamaguchi <fabs@cs.tu-berlin.de>,
	* Jacob Bower <jacob.bower@ic.ac.uk> and
	* Hiroshi Yokota for providing solutions.
	*
	* Oct.02, 2004 Hiroshi Miura <miura@da-cha.org>
	* -v0.8.2 merge code of YOKOTA Hiroshi
	* <yokota@netlab.is.tsukuba.ac.jp>.
	* Add sticky key mode interface.
	* Refactoring acpi_pcc_generate_keyinput().
	*
	* Sep.15, 2004 Hiroshi Miura <miura@da-cha.org>
	* -v0.8 Generate key input event on input subsystem.
	* This is based on yet another driver written by
	* Ryuta Nakanishi.
	*
	* Sep.10, 2004 Hiroshi Miura <miura@da-cha.org>
	* -v0.7 Change proc interface functions using seq_file
	* facility as same as other ACPI drivers.
	*
	* Aug.28, 2004 Hiroshi Miura <miura@da-cha.org>
	* -v0.6.4 Fix a silly error with status checking
	*
	* Aug.25, 2004 Hiroshi Miura <miura@da-cha.org>
	* -v0.6.3 replace read_acpi_int by standard function
	* acpi_evaluate_integer
	* some clean up and make smart copyright notice.
	* fix return value of pcc_acpi_get_key()
	* fix checking return value of acpi_bus_register_driver()
	*
	* Aug.22, 2004 David Bronaugh <dbronaugh@linuxboxen.org>
	* -v0.6.2 Add check on ACPI data (num_sifr)
	* Coding style cleanups, better error messages/handling
	* Fixed an off-by-one error in memory allocation
	*
	* Aug.21, 2004 David Bronaugh <dbronaugh@linuxboxen.org>
	* -v0.6.1 Fix a silly error with status checking
	*
	* Aug.20, 2004 David Bronaugh <dbronaugh@linuxboxen.org>
	* - v0.6 Correct brightness controls to reflect reality
	* based on information gleaned by Hiroshi Miura
	* and discussions with Hiroshi Miura
	*
	* Aug.10, 2004 Hiroshi Miura <miura@da-cha.org>
	* - v0.5 support LCD brightness control
	* based on the disclosed information by MEI.
	*
	* Jul.25, 2004 Hiroshi Miura <miura@da-cha.org>
	* - v0.4 first post version
	* add function to retrive SIFR
	*
	* Jul.24, 2004 Hiroshi Miura <miura@da-cha.org>
	* - v0.3 get proper status of hotkey
	*
	* Jul.22, 2004 Hiroshi Miura <miura@da-cha.org>
	* - v0.2 add HotKey handler
	*
	* Jul.17, 2004 Hiroshi Miura <miura@da-cha.org>
	* - v0.1 start from toshiba_acpi driver written by John Belmonte
	*
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/types.h>
	#include <linux/backlight.h>
	#include <linux/ctype.h>
	#include <linux/seq_file.h>
	#include <linux/uaccess.h>
	#include <linux/slab.h>
	#include <acpi/acpi_bus.h>
	#include <acpi/acpi_drivers.h>
	#include <linux/input.h>
	#include <linux/input/sparse-keymap.h>


	#ifndef ACPI_HOTKEY_COMPONENT
	#define ACPI_HOTKEY_COMPONENT 0x10000000
	#endif

	#define _COMPONENT ACPI_HOTKEY_COMPONENT

	MODULE_AUTHOR("Hiroshi Miura, David Bronaugh and Harald Welte");
	MODULE_DESCRIPTION("ACPI HotKey driver for Panasonic Let's Note laptops");
	MODULE_LICENSE("GPL");

	#define LOGPREFIX "pcc_acpi: "

	/* Define ACPI PATHs */
	/* Lets note hotkeys */
	#define METHOD_HKEY_QUERY "HINF"
	#define METHOD_HKEY_SQTY "SQTY"
	#define METHOD_HKEY_SINF "SINF"
	#define METHOD_HKEY_SSET "SSET"
	#define HKEY_NOTIFY 0x80

	#define ACPI_PCC_DRIVER_NAME "Panasonic Laptop Support"
	#define ACPI_PCC_DEVICE_NAME "Hotkey"
	#define ACPI_PCC_CLASS "pcc"

	#define ACPI_PCC_INPUT_PHYS "panasonic/hkey0"

	/* LCD_TYPEs: 0 = Normal, 1 = Semi-transparent
	ENV_STATEs: Normal temp=0x01, High temp=0x81, N/A=0x00
	*/
	enum SINF_BITS { SINF_NUM_BATTERIES = 0,
	SINF_LCD_TYPE,
	SINF_AC_MAX_BRIGHT,
	SINF_AC_MIN_BRIGHT,
	SINF_AC_CUR_BRIGHT,
	SINF_DC_MAX_BRIGHT,
	SINF_DC_MIN_BRIGHT,
	SINF_DC_CUR_BRIGHT,
	SINF_MUTE,
	SINF_RESERVED,
	SINF_ENV_STATE,
	SINF_STICKY_KEY = 0x80,
	};
	/* R1 handles SINF_AC_CUR_BRIGHT as SINF_CUR_BRIGHT, doesn't know AC state */

	static int acpi_pcc_hotkey_add(struct acpi_device *device);
	static int acpi_pcc_hotkey_remove(struct acpi_device *device);
	static void acpi_pcc_hotkey_notify(struct acpi_device *device, u32 event);

	static const struct acpi_device_id pcc_device_ids[] = {
	{ "MAT0012", 0},
	{ "MAT0013", 0},
	{ "MAT0018", 0},
	{ "MAT0019", 0},
	{ "", 0},
	};
	MODULE_DEVICE_TABLE(acpi, pcc_device_ids);

	#ifdef CONFIG_PM_SLEEP
	static int acpi_pcc_hotkey_resume(struct device *dev);
	#endif
	static SIMPLE_DEV_PM_OPS(acpi_pcc_hotkey_pm, NULL, acpi_pcc_hotkey_resume);

	static struct acpi_driver acpi_pcc_driver = {
	.name = ACPI_PCC_DRIVER_NAME,
	.class = ACPI_PCC_CLASS,
	.ids = pcc_device_ids,
	.ops = {
	.add = acpi_pcc_hotkey_add,
	.remove = acpi_pcc_hotkey_remove,
	.notify = acpi_pcc_hotkey_notify,
	},
	.drv.pm = &acpi_pcc_hotkey_pm,
	};

	static const struct key_entry panasonic_keymap[] = {
	{ KE_KEY, 0, { KEY_RESERVED } },
	{ KE_KEY, 1, { KEY_BRIGHTNESSDOWN } },
	{ KE_KEY, 2, { KEY_BRIGHTNESSUP } },
	{ KE_KEY, 3, { KEY_DISPLAYTOGGLE } },
	{ KE_KEY, 4, { KEY_MUTE } },
	{ KE_KEY, 5, { KEY_VOLUMEDOWN } },
	{ KE_KEY, 6, { KEY_VOLUMEUP } },
	{ KE_KEY, 7, { KEY_SLEEP } },
	{ KE_KEY, 8, { KEY_PROG1 } }, /* Change CPU boost */
	{ KE_KEY, 9, { KEY_BATTERY } },
	{ KE_KEY, 10, { KEY_SUSPEND } },
	{ KE_END, 0 }
	};

	struct pcc_acpi {
	acpi_handle handle;
	unsigned long num_sifr;
	int sticky_mode;
	u32 *sinf;
	struct acpi_device *device;
	struct input_dev *input_dev;
	struct backlight_device *backlight;
	};

	struct pcc_keyinput {
	struct acpi_hotkey *hotkey;
	};

	/* method access functions */
	static int acpi_pcc_write_sset(struct pcc_acpi *pcc, int func, int val)
	{
	union acpi_object in_objs[] = {
	{ .integer.type = ACPI_TYPE_INTEGER,
	.integer.value = func, },
	{ .integer.type = ACPI_TYPE_INTEGER,
	.integer.value = val, },
	};
	struct acpi_object_list params = {
	.count = ARRAY_SIZE(in_objs),
	.pointer = in_objs,
	};
	acpi_status status = AE_OK;

	status = acpi_evaluate_object(pcc->handle, METHOD_HKEY_SSET,
	&params, NULL);

	return (status == AE_OK) ? 0 : -EIO;
	}

	static inline int acpi_pcc_get_sqty(struct acpi_device *device)
	{
	unsigned long long s;
	acpi_status status;

	status = acpi_evaluate_integer(device->handle, METHOD_HKEY_SQTY,
	NULL, &s);
	if (ACPI_SUCCESS(status))
	return s;
	else {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"evaluation error HKEY.SQTY\n"));
	return -EINVAL;
	}
	}

	static int acpi_pcc_retrieve_biosdata(struct pcc_acpi *pcc)
	{
	acpi_status status;
	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	union acpi_object *hkey = NULL;
	int i;

	status = acpi_evaluate_object(pcc->handle, METHOD_HKEY_SINF, NULL,
	&buffer);
	if (ACPI_FAILURE(status)) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"evaluation error HKEY.SINF\n"));
	return 0;
	}

	hkey = buffer.pointer;
	if (!hkey \|\| (hkey->type != ACPI_TYPE_PACKAGE)) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid HKEY.SINF\n"));
	status = AE_ERROR;
	goto end;
	}

	if (pcc->num_sifr < hkey->package.count) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"SQTY reports bad SINF length\n"));
	status = AE_ERROR;
	goto end;
	}

	for (i = 0; i < hkey->package.count; i++) {
	union acpi_object *element = &(hkey->package.elements[i]);
	if (likely(element->type == ACPI_TYPE_INTEGER)) {
	pcc->sinf[i] = element->integer.value;
	} else
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"Invalid HKEY.SINF data\n"));
	}
	pcc->sinf[hkey->package.count] = -1;

	end:
	kfree(buffer.pointer);
	return status == AE_OK;
	}

	/* backlight API interface functions */

	/* This driver currently treats AC and DC brightness identical,
	* since we don't need to invent an interface to the core ACPI
	* logic to receive events in case a power supply is plugged in
	* or removed */

	static int bl_get(struct backlight_device *bd)
	{
	struct pcc_acpi *pcc = bl_get_data(bd);

	if (!acpi_pcc_retrieve_biosdata(pcc))
	return -EIO;

	return pcc->sinf[SINF_AC_CUR_BRIGHT];
	}

	static int bl_set_status(struct backlight_device *bd)
	{
	struct pcc_acpi *pcc = bl_get_data(bd);
	int bright = bd->props.brightness;
	int rc;

	if (!acpi_pcc_retrieve_biosdata(pcc))
	return -EIO;

	if (bright < pcc->sinf[SINF_AC_MIN_BRIGHT])
	bright = pcc->sinf[SINF_AC_MIN_BRIGHT];

	if (bright < pcc->sinf[SINF_DC_MIN_BRIGHT])
	bright = pcc->sinf[SINF_DC_MIN_BRIGHT];

	if (bright < pcc->sinf[SINF_AC_MIN_BRIGHT] \|\|
	bright > pcc->sinf[SINF_AC_MAX_BRIGHT])
	return -EINVAL;

	rc = acpi_pcc_write_sset(pcc, SINF_AC_CUR_BRIGHT, bright);
	if (rc < 0)
	return rc;

	return acpi_pcc_write_sset(pcc, SINF_DC_CUR_BRIGHT, bright);
	}

	static const struct backlight_ops pcc_backlight_ops = {
	.get_brightness = bl_get,
	.update_status = bl_set_status,
	};


	/* sysfs user interface functions */

	static ssize_t show_numbatt(struct device dev, struct device_attribute attr,
	char *buf)
	{
	struct acpi_device *acpi = to_acpi_device(dev);
	struct pcc_acpi *pcc = acpi_driver_data(acpi);

	if (!acpi_pcc_retrieve_biosdata(pcc))
	return -EIO;

	return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_NUM_BATTERIES]);
	}

	static ssize_t show_lcdtype(struct device dev, struct device_attribute attr,
	char *buf)
	{
	struct acpi_device *acpi = to_acpi_device(dev);
	struct pcc_acpi *pcc = acpi_driver_data(acpi);

	if (!acpi_pcc_retrieve_biosdata(pcc))
	return -EIO;

	return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_LCD_TYPE]);
	}

	static ssize_t show_mute(struct device dev, struct device_attribute attr,
	char *buf)
	{
	struct acpi_device *acpi = to_acpi_device(dev);
	struct pcc_acpi *pcc = acpi_driver_data(acpi);

	if (!acpi_pcc_retrieve_biosdata(pcc))
	return -EIO;

	return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_MUTE]);
	}

	static ssize_t show_sticky(struct device dev, struct device_attribute attr,
	char *buf)
	{
	struct acpi_device *acpi = to_acpi_device(dev);
	struct pcc_acpi *pcc = acpi_driver_data(acpi);

	if (!acpi_pcc_retrieve_biosdata(pcc))
	return -EIO;

	return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_STICKY_KEY]);
	}

	static ssize_t set_sticky(struct device dev, struct device_attribute attr,
	const char *buf, size_t count)
	{
	struct acpi_device *acpi = to_acpi_device(dev);
	struct pcc_acpi *pcc = acpi_driver_data(acpi);
	int val;

	if (count && sscanf(buf, "%i", &val) == 1 &&
	(val == 0 \|\| val == 1)) {
	acpi_pcc_write_sset(pcc, SINF_STICKY_KEY, val);
	pcc->sticky_mode = val;
	}

	return count;
	}

	static DEVICE_ATTR(numbatt, S_IRUGO, show_numbatt, NULL);
	static DEVICE_ATTR(lcdtype, S_IRUGO, show_lcdtype, NULL);
	static DEVICE_ATTR(mute, S_IRUGO, show_mute, NULL);
	static DEVICE_ATTR(sticky_key, S_IRUGO \| S_IWUSR, show_sticky, set_sticky);

	static struct attribute *pcc_sysfs_entries[] = {
	&dev_attr_numbatt.attr,
	&dev_attr_lcdtype.attr,
	&dev_attr_mute.attr,
	&dev_attr_sticky_key.attr,
	NULL,
	};

	static struct attribute_group pcc_attr_group = {
	.name = NULL, /* put in device directory */
	.attrs = pcc_sysfs_entries,
	};


	/* hotkey input device driver */

	static void acpi_pcc_generate_keyinput(struct pcc_acpi *pcc)
	{
	struct input_dev *hotk_input_dev = pcc->input_dev;
	int rc;
	unsigned long long result;

	rc = acpi_evaluate_integer(pcc->handle, METHOD_HKEY_QUERY,
	NULL, &result);
	if (!ACPI_SUCCESS(rc)) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"error getting hotkey status\n"));
	return;
	}
	if (!sparse_keymap_report_event(hotk_input_dev,
	result & 0xf, result & 0x80, false))
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"Unknown hotkey event: %d\n", result));
	}

	static void acpi_pcc_hotkey_notify(struct acpi_device *device, u32 event)
	{
	struct pcc_acpi *pcc = acpi_driver_data(device);

	switch (event) {
	case HKEY_NOTIFY:
	acpi_pcc_generate_keyinput(pcc);
	break;
	default:
	/* nothing to do */
	break;
	}
	}

	static int acpi_pcc_init_input(struct pcc_acpi *pcc)
	{
	struct input_dev *input_dev;
	int error;

	input_dev = input_allocate_device();
	if (!input_dev) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"Couldn't allocate input device for hotkey"));
	return -ENOMEM;
	}

	input_dev->name = ACPI_PCC_DRIVER_NAME;
	input_dev->phys = ACPI_PCC_INPUT_PHYS;
	input_dev->id.bustype = BUS_HOST;
	input_dev->id.vendor = 0x0001;
	input_dev->id.product = 0x0001;
	input_dev->id.version = 0x0100;

	error = sparse_keymap_setup(input_dev, panasonic_keymap, NULL);
	if (error) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"Unable to setup input device keymap\n"));
	goto err_free_dev;
	}

	error = input_register_device(input_dev);
	if (error) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"Unable to register input device\n"));
	goto err_free_keymap;
	}

	pcc->input_dev = input_dev;
	return 0;

	err_free_keymap:
	sparse_keymap_free(input_dev);
	err_free_dev:
	input_free_device(input_dev);
	return error;
	}

	static void acpi_pcc_destroy_input(struct pcc_acpi *pcc)
	{
	sparse_keymap_free(pcc->input_dev);
	input_unregister_device(pcc->input_dev);
	/*
	* No need to input_free_device() since core input API refcounts
	* and free()s the device.
	*/
	}

	/* kernel module interface */

	#ifdef CONFIG_PM_SLEEP
	static int acpi_pcc_hotkey_resume(struct device *dev)
	{
	struct pcc_acpi *pcc;

	if (!dev)
	return -EINVAL;

	pcc = acpi_driver_data(to_acpi_device(dev));
	if (!pcc)
	return -EINVAL;

	ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Sticky mode restore: %d\n",
	pcc->sticky_mode));

	return acpi_pcc_write_sset(pcc, SINF_STICKY_KEY, pcc->sticky_mode);
	}
	#endif

	static int acpi_pcc_hotkey_add(struct acpi_device *device)
	{
	struct backlight_properties props;
	struct pcc_acpi *pcc;
	int num_sifr, result;

	if (!device)
	return -EINVAL;

	num_sifr = acpi_pcc_get_sqty(device);

	if (num_sifr < 0 \|\| num_sifr > 255) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "num_sifr out of range"));
	return -ENODEV;
	}

	pcc = kzalloc(sizeof(struct pcc_acpi), GFP_KERNEL);
	if (!pcc) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"Couldn't allocate mem for pcc"));
	return -ENOMEM;
	}

	pcc->sinf = kzalloc(sizeof(u32) * (num_sifr + 1), GFP_KERNEL);
	if (!pcc->sinf) {
	result = -ENOMEM;
	goto out_hotkey;
	}

	pcc->device = device;
	pcc->handle = device->handle;
	pcc->num_sifr = num_sifr;
	device->driver_data = pcc;
	strcpy(acpi_device_name(device), ACPI_PCC_DEVICE_NAME);
	strcpy(acpi_device_class(device), ACPI_PCC_CLASS);

	result = acpi_pcc_init_input(pcc);
	if (result) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"Error installing keyinput handler\n"));
	goto out_sinf;
	}

	if (!acpi_pcc_retrieve_biosdata(pcc)) {
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
	"Couldn't retrieve BIOS data\n"));
	result = -EIO;
	goto out_input;
	}
	/* initialize backlight */
	memset(&props, 0, sizeof(struct backlight_properties));
	props.type = BACKLIGHT_PLATFORM;
	props.max_brightness = pcc->sinf[SINF_AC_MAX_BRIGHT];
	pcc->backlight = backlight_device_register("panasonic", NULL, pcc,
	&pcc_backlight_ops, &props);
	if (IS_ERR(pcc->backlight)) {
	result = PTR_ERR(pcc->backlight);
	goto out_input;
	}

	/* read the initial brightness setting from the hardware */
	pcc->backlight->props.brightness = pcc->sinf[SINF_AC_CUR_BRIGHT];

	/* read the initial sticky key mode from the hardware */
	pcc->sticky_mode = pcc->sinf[SINF_STICKY_KEY];

	/* add sysfs attributes */
	result = sysfs_create_group(&device->dev.kobj, &pcc_attr_group);
	if (result)
	goto out_backlight;

	return 0;

	out_backlight:
	backlight_device_unregister(pcc->backlight);
	out_input:
	acpi_pcc_destroy_input(pcc);
	out_sinf:
	kfree(pcc->sinf);
	out_hotkey:
	kfree(pcc);

	return result;
	}

	static int acpi_pcc_hotkey_remove(struct acpi_device *device)
	{
	struct pcc_acpi *pcc = acpi_driver_data(device);

	if (!device \|\| !pcc)
	return -EINVAL;

	sysfs_remove_group(&device->dev.kobj, &pcc_attr_group);

	backlight_device_unregister(pcc->backlight);

	acpi_pcc_destroy_input(pcc);

	kfree(pcc->sinf);
	kfree(pcc);

	return 0;
	}

	module_acpi_driver(acpi_pcc_driver);