panasonic-laptop: add Panasonic Let's Note laptop extras driver v0.94

This is a driver for ACPI extras such as hotkeys and backlight
brightness control on various Panasonic "Let's Note" series laptop
computers.

It exports the backlight via the backlight class device API,
and the hotkeys as input event device.  Some more esoteric
items like number of installed batteries are exported via sysfs
device attributes.

Hotkey events also generate old-style ACPI enents through
/proc/acpi/event to interoperate with current versions of acpid.

Signed-off-by: Harald Welte <laforge@gnumonks.org>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>

3 files changed, 779 insertions, 0 deletions

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index a726f3b01a6b..4ed83575393c 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -245,6 +245,17 @@ config MSI_LAPTOP
 
 	  If you have an MSI S270 laptop, say Y or M here.
 
+config PANASONIC_LAPTOP
+	tristate "Panasonic Laptop Extras"
+	depends on X86 && INPUT
+        depends on BACKLIGHT_CLASS_DEVICE
+	---help---
+	  This driver adds support for access to backlight control and hotkeys
+	  on Panasonic Let's Note laptops.
+
+	  If you have a Panasonic Let's note laptop (such as the R1(N variant),
+	  R2, R3, R5, T2, W2 and Y2 series), say Y.
+
 config COMPAL_LAPTOP
 	tristate "Compal Laptop Extras"
 	depends on X86
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index c6c13f60b452..909e2468cdc9 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_SGI_IOC4)		+= ioc4.o
 obj-$(CONFIG_SONY_LAPTOP)	+= sony-laptop.o
 obj-$(CONFIG_THINKPAD_ACPI)	+= thinkpad_acpi.o
 obj-$(CONFIG_FUJITSU_LAPTOP)	+= fujitsu-laptop.o
+obj-$(CONFIG_PANASONIC_LAPTOP)	+= panasonic-laptop.o
 obj-$(CONFIG_EEPROM_93CX6)	+= eeprom_93cx6.o
 obj-$(CONFIG_INTEL_MENLOW)	+= intel_menlow.o
 obj-$(CONFIG_ENCLOSURE_SERVICES) += enclosure.o
diff --git a/drivers/misc/panasonic-laptop.c b/drivers/misc/panasonic-laptop.c
new file mode 100644
index 000000000000..9aecda5a399c
--- /dev/null
+++ b/drivers/misc/panasonic-laptop.c
@@ -0,0 +1,767 @@
+/*
+ *  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/version.h>
+#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 <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+#include <linux/input.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, int type);
+static int acpi_pcc_hotkey_resume(struct acpi_device *device);
+
+static const struct acpi_device_id pcc_device_ids[] = {
+	{ "MAT0012", 0},
+	{ "MAT0013", 0},
+	{ "MAT0018", 0},
+	{ "MAT0019", 0},
+	{ "", 0},
+};
+
+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,
+				.resume =       acpi_pcc_hotkey_resume,
+			},
+};
+
+#define KEYMAP_SIZE		11
+static const int initial_keymap[KEYMAP_SIZE] = {
+	/*  0 */ KEY_RESERVED,
+	/*  1 */ KEY_BRIGHTNESSDOWN,
+	/*  2 */ KEY_BRIGHTNESSUP,
+	/*  3 */ KEY_DISPLAYTOGGLE,
+	/*  4 */ KEY_MUTE,
+	/*  5 */ KEY_VOLUMEDOWN,
+	/*  6 */ KEY_VOLUMEUP,
+	/*  7 */ KEY_SLEEP,
+	/*  8 */ KEY_PROG1, /* Change CPU boost */
+	/*  9 */ KEY_BATTERY,
+	/* 10 */ KEY_SUSPEND,
+};
+
+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;
+	int			keymap[KEYMAP_SIZE];
+};
+
+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;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_write_sset");
+
+	status = acpi_evaluate_object(pcc->handle, METHOD_HKEY_SSET,
+				      &params, NULL);
+
+	return status == AE_OK;
+}
+
+static inline int acpi_pcc_get_sqty(struct acpi_device *device)
+{
+	unsigned long s;
+	acpi_status status;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_get_sqty");
+
+	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, u32 *sinf)
+{
+	acpi_status status;
+	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+	union acpi_object *hkey = NULL;
+	int i;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_retrieve_biosdata");
+
+	status = acpi_evaluate_object(pcc->handle, METHOD_HKEY_SINF, 0,
+				      &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"));
+		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)) {
+			sinf[i] = element->integer.value;
+		} else
+			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+					 "Invalid HKEY.SINF data\n"));
+	}
+	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, pcc->sinf))
+		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, pcc->sinf))
+		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 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, pcc->sinf))
+		return -EIO;
+
+	return sprintf(buf, "%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, pcc->sinf))
+		return -EIO;
+
+	return sprintf(buf, "%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, pcc->sinf))
+		return -EIO;
+
+	return sprintf(buf, "%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, pcc->sinf))
+		return -EIO;
+
+	return sprintf(buf, "%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 int pcc_getkeycode(struct input_dev *dev, int scancode, int *keycode)
+{
+	struct pcc_acpi *pcc = input_get_drvdata(dev);
+
+	if (scancode >= ARRAY_SIZE(pcc->keymap))
+		return -EINVAL;
+
+	*keycode = pcc->keymap[scancode];
+
+	return 0;
+}
+
+static int keymap_get_by_keycode(struct pcc_acpi *pcc, int keycode)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(pcc->keymap); i++) {
+		if (pcc->keymap[i] == keycode)
+			return i+1;
+	}
+
+	return 0;
+}
+
+static int pcc_setkeycode(struct input_dev *dev, int scancode, int keycode)
+{
+	struct pcc_acpi *pcc = input_get_drvdata(dev);
+	int oldkeycode;
+
+	if (scancode >= ARRAY_SIZE(pcc->keymap))
+		return -EINVAL;
+
+	if (keycode < 0 || keycode > KEY_MAX)
+		return -EINVAL;
+
+	oldkeycode = pcc->keymap[scancode];
+	pcc->keymap[scancode] = keycode;
+
+	set_bit(keycode, dev->keybit);
+
+	if (!keymap_get_by_keycode(pcc, oldkeycode))
+		clear_bit(oldkeycode, dev->keybit);
+
+	return 0;
+}
+
+static void acpi_pcc_generate_keyinput(struct pcc_acpi *pcc)
+{
+	struct input_dev *hotk_input_dev = pcc->input_dev;
+	int rc;
+	int key_code, hkey_num;
+	unsigned long result;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_generate_keyinput");
+
+	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;
+	}
+
+	acpi_bus_generate_proc_event(pcc->device, HKEY_NOTIFY, result);
+
+	hkey_num = result & 0xf;
+
+	if (hkey_num < 0 || hkey_num > ARRAY_SIZE(pcc->keymap)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+				  "hotkey number out of range: %d\n",
+				  hkey_num));
+		return;
+	}
+
+	key_code = pcc->keymap[hkey_num];
+
+	if (key_code != KEY_RESERVED) {
+		int pushed = (result & 0x80) ? TRUE : FALSE;
+
+		input_report_key(hotk_input_dev, key_code, pushed);
+		input_sync(hotk_input_dev);
+	}
+
+	return;
+}
+
+static void acpi_pcc_hotkey_notify(acpi_handle handle, u32 event, void *data)
+{
+	struct pcc_acpi *pcc = (struct pcc_acpi *) data;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_hotkey_notify");
+
+	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)
+{
+	int i, rc;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_init_input");
+
+	pcc->input_dev = input_allocate_device();
+	if (!pcc->input_dev) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+				  "Couldn't allocate input device for hotkey"));
+		return -ENOMEM;
+	}
+
+	pcc->input_dev->evbit[0] = BIT(EV_KEY);
+
+	pcc->input_dev->name = ACPI_PCC_DRIVER_NAME;
+	pcc->input_dev->phys = ACPI_PCC_INPUT_PHYS;
+	pcc->input_dev->id.bustype = BUS_HOST;
+	pcc->input_dev->id.vendor = 0x0001;
+	pcc->input_dev->id.product = 0x0001;
+	pcc->input_dev->id.version = 0x0100;
+	pcc->input_dev->getkeycode = pcc_getkeycode;
+	pcc->input_dev->setkeycode = pcc_setkeycode;
+
+	/* load initial keymap */
+	memcpy(pcc->keymap, initial_keymap, sizeof(pcc->keymap));
+
+	for (i = 0; i < ARRAY_SIZE(pcc->keymap); i++)
+		__set_bit(pcc->keymap[i], pcc->input_dev->keybit);
+	__clear_bit(KEY_RESERVED, pcc->input_dev->keybit);
+
+	input_set_drvdata(pcc->input_dev, pcc);
+
+	rc = input_register_device(pcc->input_dev);
+	if (rc < 0)
+		input_free_device(pcc->input_dev);
+
+	return rc;
+}
+
+/* kernel module interface */
+
+static int acpi_pcc_hotkey_resume(struct acpi_device *device)
+{
+	struct pcc_acpi *pcc = acpi_driver_data(device);
+	acpi_status status = AE_OK;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_hotkey_resume");
+
+	if (device == NULL || pcc == NULL)
+		return -EINVAL;
+
+	ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Sticky mode restore: %d\n",
+			  pcc->sticky_mode));
+
+	status = acpi_pcc_write_sset(pcc, SINF_STICKY_KEY, pcc->sticky_mode);
+
+	return status == AE_OK ? 0 : -EINVAL;
+}
+
+static int acpi_pcc_hotkey_add(struct acpi_device *device)
+{
+	acpi_status status;
+	struct pcc_acpi *pcc;
+	int num_sifr, result;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_hotkey_add");
+
+	if (!device)
+		return -EINVAL;
+
+	num_sifr = acpi_pcc_get_sqty(device);
+
+	if (num_sifr > 255) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "num_sifr too large"));
+		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;
+	acpi_driver_data(device) = 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;
+	}
+
+	/* initialize hotkey input device */
+	status = acpi_install_notify_handler(pcc->handle, ACPI_DEVICE_NOTIFY,
+					     acpi_pcc_hotkey_notify, pcc);
+
+	if (ACPI_FAILURE(status)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+				  "Error installing notify handler\n"));
+		result = -ENODEV;
+		goto out_input;
+	}
+
+	/* initialize backlight */
+	pcc->backlight = backlight_device_register("panasonic", NULL, pcc,
+						   &pcc_backlight_ops);
+	if (IS_ERR(pcc->backlight))
+		goto out_notify;
+
+	if (!acpi_pcc_retrieve_biosdata(pcc, pcc->sinf)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+				 "Couldn't retrieve BIOS data\n"));
+		goto out_backlight;
+	}
+
+	/* read the initial brightness setting from the hardware */
+	pcc->backlight->props.max_brightness =
+					pcc->sinf[SINF_AC_MAX_BRIGHT];
+	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_notify:
+	acpi_remove_notify_handler(pcc->handle, ACPI_DEVICE_NOTIFY,
+				   acpi_pcc_hotkey_notify);
+out_input:
+	input_unregister_device(pcc->input_dev);
+	/* no need to input_free_device() since core input API refcount and
+	 * free()s the device */
+out_sinf:
+	kfree(pcc->sinf);
+out_hotkey:
+	kfree(pcc);
+
+	return result;
+}
+
+static int __init acpi_pcc_init(void)
+{
+	int result = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_init");
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	result = acpi_bus_register_driver(&acpi_pcc_driver);
+	if (result < 0) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+				  "Error registering hotkey driver\n"));
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int acpi_pcc_hotkey_remove(struct acpi_device *device, int type)
+{
+	struct pcc_acpi *pcc = acpi_driver_data(device);
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_hotkey_remove");
+
+	if (!device || !pcc)
+		return -EINVAL;
+
+	sysfs_remove_group(&device->dev.kobj, &pcc_attr_group);
+
+	backlight_device_unregister(pcc->backlight);
+
+	acpi_remove_notify_handler(pcc->handle, ACPI_DEVICE_NOTIFY,
+				   acpi_pcc_hotkey_notify);
+
+	input_unregister_device(pcc->input_dev);
+	/* no need to input_free_device() since core input API refcount and
+	 * free()s the device */
+
+	kfree(pcc->sinf);
+	kfree(pcc);
+
+	return 0;
+}
+
+static void __exit acpi_pcc_exit(void)
+{
+	ACPI_FUNCTION_TRACE("acpi_pcc_exit");
+
+	acpi_bus_unregister_driver(&acpi_pcc_driver);
+}
+
+module_init(acpi_pcc_init);
+module_exit(acpi_pcc_exit);