Staging: add pcc-acpi driver

Adds the pcc-acpi driver to the staging tree.

From: Hiroshi Miura <miura@da-cha.org>
Cc: YOKOTA Hiroshi <yokota@netlab.is.tsukuba.ac.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/Kconfig

@@ -43,4 +43,6 @@ source "drivers/staging/echo/Kconfig"
 
 source "drivers/staging/at76_usb/Kconfig"
 
+source "drivers/staging/pcc-acpi/Kconfig"
+
 endif # STAGING

drivers/staging/Makefile

@@ -13,3 +13,4 @@ obj-$(CONFIG_W35UND)		+= winbond/
 obj-$(CONFIG_PRISM2_USB)	+= wlan-ng/
 obj-$(CONFIG_ECHO)		+= echo/
 obj-$(CONFIG_USB_ATMEL)		+= at76_usb/
+obj-$(CONFIG_PCC_ACPI)		+= pcc-acpi/

drivers/staging/pcc-acpi/Kconfig

@@ -0,0 +1,11 @@
+config PCC_ACPI
+	tristate "Panasonic ACPI Hotkey support"
+	depends on ACPI
+	default n
+	---help---
+	  This driver provides support for Panasonic hotkeys through the
+	  ACPI interface.  This works for the Panasonic R1 (N variant),
+	  R2, R3, T2, W2, and Y2 laptops.
+
+	  To compile this driver as a module, choose M here. The module
+	  will be called pcc-acpi.

drivers/staging/pcc-acpi/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_PCC_ACPI)		+= pcc-acpi.o

drivers/staging/pcc-acpi/TODO

@@ -0,0 +1,7 @@
+TODO:
+	- Lindent fixes
+	- checkpatch.pl fixes
+	- verify that the acpi interface is correct
+	- remove /proc dependancy if needed (not sure yet.)
+
+Please send any patches for this driver to Greg Kroah-Hartman <greg@kroah.com>

drivers/staging/pcc-acpi/pcc-acpi.c

@@ -0,0 +1,974 @@
+/*
+ *  Panasonic HotKey and lcd brightness control Extra 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>
+ *
+ *  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:
+ *
+ * 	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 to allow HAL to access.
+ * 			merge dbronaugh's enhancement
+ * 			Aug.17, 2004 David Bronaugh (dbronaugh)
+ *  				- Added screen brightness setting interface
+ *				  Thanks to the FreeBSD crew (acpi_panasonic.c authors)
+ * 				  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_generete_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
+ *
+ */
+
+#define ACPI_PCC_VERSION	"0.9"
+
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/proc_fs.h>
+#include <linux/ctype.h>
+#include <linux/seq_file.h>
+#include <asm/uaccess.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+#include <linux/input.h>
+
+
+/*************************************************************************
+ * "seq" file template definition.
+ */
+/* "seq" initializer */
+#define SEQ_OPEN_FS(_open_func_name_, _show_func_name_) \
+static int _open_func_name_(struct inode *inode, struct file *file) \
+{								      \
+	return single_open(file, _show_func_name_, PDE(inode)->data);  \
+}
+
+/*-------------------------------------------------------------------------
+ * "seq" fops template for read-only files.
+ */
+#define SEQ_FILEOPS_R(_open_func_name_) \
+{ \
+	.open	 = _open_func_name_,		  \
+	.read	 = seq_read,			  \
+	.llseek	 = seq_lseek,			  \
+	.release = single_release,		  \
+}
+
+/*------------------------------------------------------------------------
+ * "seq" fops template for read-write files.
+ */
+#define SEQ_FILEOPS_RW(_open_func_name_, _write_func_name_) \
+{ \
+	.open	 = _open_func_name_ ,		  \
+	.read	 = seq_read,			  \
+	.write	 = _write_func_name_,		  \
+	.llseek	 = seq_lseek,			  \
+	.release = single_release,		  \
+}
+
+/*
+ * "seq" file template definition ended.
+ ***************************************************************************
+ */
+#ifndef ACPI_HOTKEY_COMPONENT
+#define ACPI_HOTKEY_COMPONENT	0x10000000
+#endif
+
+#define _COMPONENT		ACPI_HOTKEY_COMPONENT
+ACPI_MODULE_NAME("pcc_acpi")
+
+MODULE_AUTHOR("Hiroshi Miura");
+MODULE_DESCRIPTION("ACPI HotKey driver for Panasonic Lets 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
+
+/* for brightness control */
+#define LCD_MAX_BRIGHTNESS 255
+/* This may be magical -- beware */
+#define LCD_BRIGHTNESS_INCREMENT 17
+/* Registers of SINF */
+#define SINF_LCD_BRIGHTNESS 4
+
+/*******************************************************************
+ *
+ * definitions for /proc/ interface
+ *
+ *******************************************************************/
+#define ACPI_PCC_DRIVER_NAME	"PCC Extra Driver"
+#define ACPI_PCC_DEVICE_NAME	"PCCExtra"
+#define ACPI_PCC_CLASS		"pcc"
+#define PROC_PCC		ACPI_PCC_CLASS
+
+#define ACPI_PCC_INPUT_PHYS	"panasonic/hkey0"
+
+/* This is transitional definition */
+#ifndef KEY_BATT
+# define KEY_BATT 227
+#endif
+
+#define PROC_STR_MAX_LEN  8
+
+/* 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,      /* 1 */
+		 SINF_AC_MAX_BRIGHT, SINF_AC_MIN_BRIGHT, SINF_AC_CUR_BRIGHT,  /* 2, 3, 4 */
+		             /* 4 = R1 only handle SINF_AC_CUR_BRIGHT as SINF_CUR_BRIGHT and don't know AC state */
+		 SINF_DC_MAX_BRIGHT, SINF_DC_MIN_BRIGHT, SINF_DC_CUR_BRIGHT,  /* 5, 6, 7 */
+		 SINF_MUTE,
+		 SINF_RESERVED,      SINF_ENV_STATE, /* 9, 10 */
+		 SINF_STICKY_KEY = 0x80,
+};
+
+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},
+};
+MODULE_DEVICE_TABLE(acpi, pcc_device_ids);
+
+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,
+			},
+};
+
+struct acpi_hotkey {
+	acpi_handle		handle;
+	struct acpi_device	*device;
+	struct proc_dir_entry   *proc_dir_entry;
+	unsigned long		num_sifr;
+	unsigned long		status;
+	struct input_dev	*input_dev;
+	int			sticky_mode;
+};
+
+struct pcc_keyinput {
+	struct acpi_hotkey      *hotkey;
+	int key_mode;
+};
+
+/* --------------------------------------------------------------------------
+                           method access functions
+   -------------------------------------------------------------------------- */
+static int acpi_pcc_write_sset(struct acpi_hotkey *hotkey, 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(hotkey->handle, METHOD_HKEY_SSET, &params, NULL);
+
+	return_VALUE(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_VALUE(s);
+	} else {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+				  "evaluation error HKEY.SQTY\n"));
+		return_VALUE(-EINVAL);
+	}
+}
+
+static int acpi_pcc_retrieve_biosdata(struct acpi_hotkey *hotkey, 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(hotkey->handle, METHOD_HKEY_SINF, 0 , &buffer);
+	if (ACPI_FAILURE(status)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "evaluation error HKEY.SINF\n"));
+		return_VALUE(0);
+	}
+
+	hkey = buffer.pointer;
+	if (!hkey || (hkey->type != ACPI_TYPE_PACKAGE)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid HKEY.SINF\n"));
+		goto end;
+	}
+
+	if (hotkey->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_VALUE(status == AE_OK);
+}
+
+static int acpi_pcc_read_sinf_field(struct seq_file *seq, int field)
+{
+	struct acpi_hotkey *hotkey = (struct acpi_hotkey *) seq->private;
+	u32* sinf = kmalloc(sizeof(u32) * (hotkey->num_sifr + 1), GFP_KERNEL);
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_read_sinf_field");
+
+	if (!sinf) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Couldn't allocate %li bytes\n",
+		       sizeof(u32) * hotkey->num_sifr));
+		return_VALUE(0);
+	}
+
+	if (acpi_pcc_retrieve_biosdata(hotkey, sinf)) {
+		seq_printf(seq, "%u\n",	sinf[field]);
+	} else {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Couldn't retrieve BIOS data\n"));
+	}
+
+	kfree(sinf);
+	return_VALUE(0);
+}
+
+/* --------------------------------------------------------------------------
+                       user interface functions
+   -------------------------------------------------------------------------- */
+/* read methods */
+/* Sinf read methods */
+#define PCC_SINF_READ_F(_name_, FUNC) \
+static int _name_  (struct seq_file *seq, void *offset) \
+{ \
+	return acpi_pcc_read_sinf_field(seq, (FUNC)); \
+}
+
+PCC_SINF_READ_F(acpi_pcc_numbatteries_show,      SINF_NUM_BATTERIES);
+PCC_SINF_READ_F(acpi_pcc_lcdtype_show,           SINF_LCD_TYPE);
+PCC_SINF_READ_F(acpi_pcc_ac_brightness_max_show, SINF_AC_MAX_BRIGHT);
+PCC_SINF_READ_F(acpi_pcc_ac_brightness_min_show, SINF_AC_MIN_BRIGHT);
+PCC_SINF_READ_F(acpi_pcc_ac_brightness_show,     SINF_AC_CUR_BRIGHT);
+PCC_SINF_READ_F(acpi_pcc_dc_brightness_max_show, SINF_DC_MAX_BRIGHT);
+PCC_SINF_READ_F(acpi_pcc_dc_brightness_min_show, SINF_DC_MIN_BRIGHT);
+PCC_SINF_READ_F(acpi_pcc_dc_brightness_show,     SINF_DC_CUR_BRIGHT);
+PCC_SINF_READ_F(acpi_pcc_brightness_show,        SINF_AC_CUR_BRIGHT);
+PCC_SINF_READ_F(acpi_pcc_mute_show,              SINF_MUTE);
+
+static int acpi_pcc_sticky_key_show(struct seq_file *seq, void *offset)
+{
+	struct acpi_hotkey *hotkey = seq->private;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_sticky_key_show");
+
+	if (!hotkey || !hotkey->device) {
+		return_VALUE(0);
+	}
+
+	seq_printf(seq, "%d\n", hotkey->sticky_mode);
+
+	return_VALUE(0);
+}
+
+static int acpi_pcc_keyinput_show(struct seq_file *seq, void *offset)
+{
+	struct acpi_hotkey 	*hotkey = (struct acpi_hotkey *) seq->private;
+	struct input_dev 	*hotk_input_dev = hotkey->input_dev;
+	struct pcc_keyinput 	*keyinput = input_get_drvdata(hotk_input_dev);
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_keyinput_show");
+
+	seq_printf(seq, "%d\n", keyinput->key_mode);
+
+	return_VALUE(0);
+}
+
+static int acpi_pcc_version_show(struct seq_file *seq, void *offset)
+{
+	struct acpi_hotkey *hotkey = (struct acpi_hotkey *) seq->private;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_version_show");
+
+	if (!hotkey || !hotkey->device)
+		return 0;
+
+	seq_printf(seq, "%s version %s\n", ACPI_PCC_DRIVER_NAME, ACPI_PCC_VERSION);
+	seq_printf(seq, "%li functions\n", hotkey->num_sifr);
+
+	return_VALUE(0);
+}
+
+/* write methods */
+static ssize_t acpi_pcc_write_single_flag (struct file *file,
+                                           const char __user *buffer,
+                                           size_t count,
+                                           int sinf_func)
+{
+	struct seq_file		*seq = file->private_data;
+	struct acpi_hotkey	*hotkey = seq->private;
+	char			write_string[PROC_STR_MAX_LEN];
+	u32 			val;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_write_single_flag");
+
+	if (!hotkey || (count > sizeof(write_string) - 1)) {
+		return_VALUE(-EINVAL);
+        }
+
+	if (copy_from_user(write_string, buffer, count)) {
+		return_VALUE(-EFAULT);
+        }
+	write_string[count] = '\0';
+
+	if (sscanf(write_string, "%i", &val) == 1 && (val == 0 || val == 1)) {
+		acpi_pcc_write_sset(hotkey, sinf_func, val);
+	}
+
+	return_VALUE(count);
+}
+
+static unsigned long acpi_pcc_write_brightness(struct file *file, const char __user *buffer,
+					       size_t count,
+					       int min_index, int max_index,
+					       int cur_index)
+{
+	struct seq_file		*seq = (struct seq_file *)file->private_data;
+	struct acpi_hotkey	*hotkey = (struct acpi_hotkey *)seq->private;
+	char			write_string[PROC_STR_MAX_LEN];
+	u32 bright;
+	u32* sinf = kmalloc(sizeof(u32) * (hotkey->num_sifr + 1), GFP_KERNEL);
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_write_brightness");
+
+	if (!hotkey || (count > sizeof(write_string) - 1))
+		return_VALUE(-EINVAL);
+
+	if (!sinf) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Couldn't allocate %li bytes\n",
+		       sizeof(u32) * hotkey->num_sifr));
+		return_VALUE(-EFAULT);
+	}
+
+	if (copy_from_user(write_string, buffer, count))
+		return_VALUE(-EFAULT);
+
+	write_string[count] = '\0';
+
+	if (!acpi_pcc_retrieve_biosdata(hotkey, sinf)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Couldn't retrieve BIOS data\n"));
+		goto end;
+	}
+
+	if (sscanf(write_string, "%i", &bright) == 1 &&
+		bright >= sinf[min_index] && bright <= sinf[max_index]) {
+			acpi_pcc_write_sset(hotkey, cur_index, bright);
+	}
+
+end:
+	kfree(sinf);
+	return_VALUE(count);
+}
+
+static ssize_t acpi_pcc_write_ac_brightness(struct file *file, const char __user *buffer,
+					 size_t count, loff_t *ppos)
+{
+	return acpi_pcc_write_brightness(file, buffer, count, SINF_AC_MIN_BRIGHT,
+					 SINF_AC_MAX_BRIGHT,
+					 SINF_AC_CUR_BRIGHT);
+}
+
+static ssize_t acpi_pcc_write_dc_brightness(struct file *file, const char __user *buffer,
+					 size_t count, loff_t *ppos)
+{
+	return acpi_pcc_write_brightness(file, buffer, count, SINF_DC_MIN_BRIGHT,
+					 SINF_DC_MAX_BRIGHT,
+					 SINF_DC_CUR_BRIGHT);
+}
+
+static ssize_t acpi_pcc_write_no_brightness(struct file *file, const char __user *buffer,
+					 size_t count, loff_t *ppos)
+{
+	return acpi_pcc_write_brightness(file, buffer, count, SINF_AC_MIN_BRIGHT,
+					 SINF_AC_MAX_BRIGHT,
+					 SINF_AC_CUR_BRIGHT);
+}
+
+static ssize_t acpi_pcc_write_mute (struct file *file,
+				    const char __user *buffer,
+				    size_t count, loff_t *ppos)
+{
+	return acpi_pcc_write_single_flag(file, buffer, count, SINF_MUTE);
+}
+
+static ssize_t acpi_pcc_write_sticky_key (struct file *file,
+					  const char __user *buffer,
+					  size_t count, loff_t *ppos)
+{
+	return acpi_pcc_write_single_flag(file, buffer, count, SINF_STICKY_KEY);
+}
+
+static ssize_t acpi_pcc_write_keyinput(struct file *file, const char __user *buffer,
+					 size_t count, loff_t *ppos)
+{
+	struct seq_file		*seq = (struct seq_file *)file->private_data;
+	struct acpi_hotkey	*hotkey = (struct acpi_hotkey *)seq->private;
+	struct pcc_keyinput 	*keyinput;
+	char			write_string[PROC_STR_MAX_LEN];
+	int			key_mode;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_write_keyinput");
+
+	if (!hotkey || (count > sizeof(write_string) - 1))
+		return_VALUE(-EINVAL);
+
+	if (copy_from_user(write_string, buffer, count))
+		return_VALUE(-EFAULT);
+
+	write_string[count] = '\0';
+
+	if (sscanf(write_string, "%i", &key_mode) == 1 && (key_mode == 0 || key_mode == 1)) {
+		keyinput = (struct pcc_keyinput *)input_get_drvdata(hotkey->input_dev);
+		keyinput->key_mode = key_mode;
+	}
+
+	return_VALUE(count);
+}
+
+/* --------------------------------------------------------------------------
+                            hotkey driver
+   -------------------------------------------------------------------------- */
+static void acpi_pcc_generete_keyinput(struct acpi_hotkey *hotkey)
+{
+	struct input_dev    *hotk_input_dev = hotkey->input_dev;
+	struct pcc_keyinput *keyinput = input_get_drvdata(hotk_input_dev);
+	int hinf = hotkey->status;
+	int key_code, hkey_num;
+	const int key_map[] = {
+		/*  0 */ -1,
+		/*  1 */ KEY_BRIGHTNESSDOWN,
+		/*  2 */ KEY_BRIGHTNESSUP,
+		/*  3 */ -1, /* vga/lcd switch event is not occur on hotkey driver. */
+		/*  4 */ KEY_MUTE,
+		/*  5 */ KEY_VOLUMEDOWN,
+		/*  6 */ KEY_VOLUMEUP,
+		/*  7 */ KEY_SLEEP,
+		/*  8 */ -1, /* Change CPU boost: do nothing */
+		/*  9 */ KEY_BATT,
+		/* 10 */ KEY_SUSPEND,
+	};
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_generete_keyinput");
+
+	if (keyinput->key_mode == 0) { return_VOID; }
+
+	hkey_num = hinf & 0xf;
+
+	if ((       0 > hkey_num	   ) ||
+	    (hkey_num > ARRAY_SIZE(key_map))) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+				  "hotkey number out of range: %d\n",
+				  hkey_num));
+		return_VOID;
+	}
+
+	key_code = key_map[hkey_num];
+
+	if (key_code != -1) {
+		int pushed = (hinf & 0x80) ? TRUE : FALSE;
+
+		input_report_key(hotk_input_dev, key_code, pushed);
+		input_sync(hotk_input_dev);
+	}
+}
+
+static int acpi_pcc_hotkey_get_key(struct acpi_hotkey *hotkey)
+{
+	unsigned long result;
+	acpi_status status = AE_OK;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_hotkey_get_key");
+
+	status = acpi_evaluate_integer(hotkey->handle, METHOD_HKEY_QUERY, NULL, &result);
+	if (likely(ACPI_SUCCESS(status))) {
+		hotkey->status = result;
+	} else {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "error getting hotkey status\n"));
+	}
+
+	return_VALUE(status == AE_OK);
+}
+
+void acpi_pcc_hotkey_notify(acpi_handle handle, u32 event, void *data)
+{
+	struct acpi_hotkey *hotkey = (struct acpi_hotkey *) data;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_hotkey_notify");
+
+	switch(event) {
+	case HKEY_NOTIFY:
+		if (acpi_pcc_hotkey_get_key(hotkey)) {
+			/* generate event like '"pcc HKEY 00000080 00000084"' when Fn+F4 pressed */
+			acpi_bus_generate_proc_event(hotkey->device, event, hotkey->status);
+		}
+		acpi_pcc_generete_keyinput(hotkey);
+		break;
+	default:
+		/* nothing to do */
+		break;
+	}
+	return_VOID;
+}
+
+/* --------------------------------------------------------------------------
+                              FS Interface (/proc)
+   -------------------------------------------------------------------------- */
+/* oepn proc file fs*/
+SEQ_OPEN_FS(acpi_pcc_dc_brightness_open_fs, acpi_pcc_dc_brightness_show);
+SEQ_OPEN_FS(acpi_pcc_numbatteries_open_fs,  acpi_pcc_numbatteries_show);
+SEQ_OPEN_FS(acpi_pcc_lcdtype_open_fs,  acpi_pcc_lcdtype_show);
+SEQ_OPEN_FS(acpi_pcc_ac_brightness_max_open_fs, acpi_pcc_ac_brightness_max_show);
+SEQ_OPEN_FS(acpi_pcc_ac_brightness_min_open_fs,  acpi_pcc_ac_brightness_min_show);
+SEQ_OPEN_FS(acpi_pcc_ac_brightness_open_fs, acpi_pcc_ac_brightness_show);
+SEQ_OPEN_FS(acpi_pcc_dc_brightness_max_open_fs, acpi_pcc_dc_brightness_max_show);
+SEQ_OPEN_FS(acpi_pcc_dc_brightness_min_open_fs, acpi_pcc_dc_brightness_min_show);
+SEQ_OPEN_FS(acpi_pcc_brightness_open_fs,  acpi_pcc_brightness_show);
+SEQ_OPEN_FS(acpi_pcc_mute_open_fs, acpi_pcc_mute_show);
+SEQ_OPEN_FS(acpi_pcc_version_open_fs, acpi_pcc_version_show);
+SEQ_OPEN_FS(acpi_pcc_keyinput_open_fs, acpi_pcc_keyinput_show);
+SEQ_OPEN_FS(acpi_pcc_sticky_key_open_fs, acpi_pcc_sticky_key_show);
+
+typedef struct file_operations fops_t;
+static fops_t acpi_pcc_numbatteries_fops = SEQ_FILEOPS_R (acpi_pcc_numbatteries_open_fs);
+static fops_t acpi_pcc_lcdtype_fops = SEQ_FILEOPS_R (acpi_pcc_lcdtype_open_fs);
+static fops_t acpi_pcc_mute_fops = SEQ_FILEOPS_RW(acpi_pcc_mute_open_fs, acpi_pcc_write_mute);
+static fops_t acpi_pcc_ac_brightness_fops = SEQ_FILEOPS_RW(acpi_pcc_ac_brightness_open_fs, acpi_pcc_write_ac_brightness);
+static fops_t acpi_pcc_ac_brightness_max_fops = SEQ_FILEOPS_R(acpi_pcc_ac_brightness_max_open_fs);
+static fops_t acpi_pcc_ac_brightness_min_fops = SEQ_FILEOPS_R(acpi_pcc_ac_brightness_min_open_fs);
+static fops_t acpi_pcc_dc_brightness_fops = SEQ_FILEOPS_RW(acpi_pcc_dc_brightness_open_fs, acpi_pcc_write_dc_brightness);
+static fops_t acpi_pcc_dc_brightness_max_fops = SEQ_FILEOPS_R(acpi_pcc_dc_brightness_max_open_fs);
+static fops_t acpi_pcc_dc_brightness_min_fops = SEQ_FILEOPS_R(acpi_pcc_dc_brightness_min_open_fs);
+static fops_t acpi_pcc_brightness_fops = SEQ_FILEOPS_RW(acpi_pcc_brightness_open_fs, acpi_pcc_write_no_brightness);
+static fops_t acpi_pcc_sticky_key_fops = SEQ_FILEOPS_RW(acpi_pcc_sticky_key_open_fs, acpi_pcc_write_sticky_key);
+static fops_t acpi_pcc_keyinput_fops = SEQ_FILEOPS_RW(acpi_pcc_keyinput_open_fs, acpi_pcc_write_keyinput);
+static fops_t acpi_pcc_version_fops = SEQ_FILEOPS_R (acpi_pcc_version_open_fs);
+
+typedef struct _ProcItem
+{
+	const char* name;
+	struct file_operations *fops;
+	mode_t flag;
+} ProcItem;
+
+/* Note: These functions map *exactly* to the SINF/SSET functions */
+ProcItem pcc_proc_items_sifr[] =
+{
+	{ "num_batteries",      &acpi_pcc_numbatteries_fops,     S_IRUGO },
+	{ "lcd_type",           &acpi_pcc_lcdtype_fops,          S_IRUGO },
+	{ "ac_brightness_max" , &acpi_pcc_ac_brightness_max_fops,S_IRUGO },
+	{ "ac_brightness_min" , &acpi_pcc_ac_brightness_min_fops,S_IRUGO },
+	{ "ac_brightness" ,     &acpi_pcc_ac_brightness_fops,    S_IFREG | S_IRUGO | S_IWUSR },
+	{ "dc_brightness_max" , &acpi_pcc_dc_brightness_max_fops,S_IRUGO },
+	{ "dc_brightness_min" , &acpi_pcc_dc_brightness_min_fops,S_IRUGO },
+	{ "dc_brightness" ,     &acpi_pcc_dc_brightness_fops,    S_IFREG | S_IRUGO | S_IWUSR },
+	{ "brightness" ,        &acpi_pcc_brightness_fops,    S_IFREG | S_IRUGO | S_IWUSR },
+	{ "mute",               &acpi_pcc_mute_fops,             S_IFREG | S_IRUGO | S_IWUSR },
+	{ NULL, NULL, 0 },
+};
+
+ProcItem pcc_proc_items[] =
+{
+	{ "sticky_key",		&acpi_pcc_sticky_key_fops,	 S_IFREG | S_IRUGO | S_IWUSR },
+	{ "keyinput",           &acpi_pcc_keyinput_fops,         S_IFREG | S_IRUGO | S_IWUSR },
+	{ "version",            &acpi_pcc_version_fops,          S_IRUGO },
+	{ NULL, NULL, 0 },
+};
+
+static int acpi_pcc_add_device(struct acpi_device *device,
+                                      ProcItem *proc_items,
+                                      int num)
+{
+	struct proc_dir_entry* proc;
+	ProcItem* item;
+	int i;
+	struct acpi_hotkey *hotkey = (struct acpi_hotkey*)acpi_driver_data(device);
+
+	for (item = proc_items, i = 0; item->name && i < num; ++item, ++i) {
+		proc = create_proc_entry(item->name, item->flag, hotkey->proc_dir_entry);
+		if (likely(proc)) {
+			proc->proc_fops = item->fops;
+			proc->data = hotkey;
+			proc->owner = THIS_MODULE;
+		} else {
+			while (i-- > 0) {
+				item--;
+				remove_proc_entry(item->name, hotkey->proc_dir_entry);
+			}
+			return -ENODEV;
+		}
+	}
+	return 0;
+}
+
+static int acpi_pcc_proc_init(struct acpi_device *device)
+{
+	struct proc_dir_entry* acpi_pcc_dir;
+	struct acpi_hotkey *hotkey = (struct acpi_hotkey*)acpi_driver_data(device);
+	acpi_status status;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_proc_init");
+
+	acpi_pcc_dir = proc_mkdir(PROC_PCC, acpi_root_dir);
+
+	if (unlikely(!acpi_pcc_dir)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Couldn't create dir in /proc\n"));
+		return_VALUE(-ENODEV);
+	}
+
+	acpi_pcc_dir->owner = THIS_MODULE;
+	hotkey->proc_dir_entry = acpi_pcc_dir;
+
+	status =  acpi_pcc_add_device(device, pcc_proc_items_sifr, hotkey->num_sifr);
+	status |= acpi_pcc_add_device(device, pcc_proc_items, sizeof(pcc_proc_items)/sizeof(ProcItem));
+	if (unlikely(status)) {
+		remove_proc_entry(PROC_PCC, acpi_root_dir);
+		hotkey->proc_dir_entry = NULL;
+		return_VALUE(-ENODEV);
+	}
+
+	return_VALUE(status);
+}
+
+static void acpi_pcc_remove_device(struct acpi_device *device,
+                                          ProcItem *proc_items,
+                                          int num)
+{
+	struct acpi_hotkey *hotkey = (struct acpi_hotkey*)acpi_driver_data(device);
+	ProcItem* item;
+	int i;
+
+	for (item = proc_items, i = 0; item->name != NULL && i < num; ++item, ++i) {
+		remove_proc_entry(item->name, hotkey->proc_dir_entry);
+	}
+
+	return;
+}
+
+/* --------------------------------------------------------------------------
+                             input init
+   -------------------------------------------------------------------------- */
+static int acpi_pcc_init_input(struct acpi_hotkey *hotkey)
+{
+	struct input_dev *hotk_input_dev;
+	struct pcc_keyinput *pcc_keyinput;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_init_input");
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,15)
+	hotk_input_dev = input_allocate_device();
+	if (!hotk_input_dev) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Couldn't allocate input device for hotkey"));
+		return_VALUE(-ENOMEM);
+	}
+#else
+	hotk_input_dev = kcalloc(1, sizeof(struct input_dev),GFP_KERNEL);
+	if (hotk_input_dev == NULL) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Couldn't allocate mem for hotkey"));
+		return_VALUE(-ENOMEM);
+	}
+#endif
+
+	pcc_keyinput = kcalloc(1,sizeof(struct pcc_keyinput),GFP_KERNEL);
+
+	if (pcc_keyinput == NULL) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Couldn't allocate mem for hotkey"));
+		input_unregister_device(hotk_input_dev);
+		return_VALUE(-ENOMEM);
+	}
+
+	hotk_input_dev->evbit[0] = BIT(EV_KEY);
+
+	set_bit(KEY_BRIGHTNESSDOWN, hotk_input_dev->keybit);
+	set_bit(KEY_BRIGHTNESSUP, hotk_input_dev->keybit);
+	set_bit(KEY_MUTE, hotk_input_dev->keybit);
+	set_bit(KEY_VOLUMEDOWN, hotk_input_dev->keybit);
+	set_bit(KEY_VOLUMEUP, hotk_input_dev->keybit);
+	set_bit(KEY_SLEEP, hotk_input_dev->keybit);
+	set_bit(KEY_BATT, hotk_input_dev->keybit);
+	set_bit(KEY_SUSPEND, hotk_input_dev->keybit);
+
+	hotk_input_dev->name = ACPI_PCC_DRIVER_NAME;
+	hotk_input_dev->phys = ACPI_PCC_INPUT_PHYS;
+	hotk_input_dev->id.bustype = 0x1a; /* XXX FIXME: BUS_I8042? */
+	hotk_input_dev->id.vendor = 0x0001;
+	hotk_input_dev->id.product = 0x0001;
+	hotk_input_dev->id.version = 0x0100;
+
+	pcc_keyinput->key_mode = 1; /* default on */
+	pcc_keyinput->hotkey = hotkey;
+
+	input_set_drvdata(hotk_input_dev, pcc_keyinput);
+
+	hotkey->input_dev = hotk_input_dev;
+
+
+	input_register_device(hotk_input_dev);
+
+	return_VALUE(0);
+}
+
+/* --------------------------------------------------------------------------
+                         module init
+   -------------------------------------------------------------------------- */
+
+static int acpi_pcc_hotkey_resume(struct acpi_device *device)
+{
+	struct acpi_hotkey *hotkey = acpi_driver_data(device);
+	acpi_status	    status = AE_OK;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_hotkey_resume");
+
+	if (device == NULL || hotkey == NULL) { return_VALUE(-EINVAL); }
+
+	ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Sticky mode restore: %d\n", hotkey->sticky_mode));
+
+	status = acpi_pcc_write_sset(hotkey, SINF_STICKY_KEY, hotkey->sticky_mode);
+
+	return_VALUE(status == AE_OK ? 0 : -EINVAL);
+}
+
+static int acpi_pcc_hotkey_add (struct acpi_device *device)
+{
+	acpi_status		status = AE_OK;
+	struct acpi_hotkey	*hotkey = NULL;
+	int num_sifr, result;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_hotkey_add");
+
+	if (!device) {
+		return_VALUE(-EINVAL);
+	}
+
+	num_sifr = acpi_pcc_get_sqty(device);
+
+	if (num_sifr > 255) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "num_sifr too large"));
+		return_VALUE(-ENODEV);
+	}
+
+	hotkey = kmalloc(sizeof(struct acpi_hotkey), GFP_KERNEL);
+	if (!hotkey) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Couldn't allocate mem for hotkey"));
+		return_VALUE(-ENOMEM);
+	}
+
+	memset(hotkey, 0, sizeof(struct acpi_hotkey));
+
+	hotkey->device = device;
+	hotkey->handle = device->handle;
+	hotkey->num_sifr = num_sifr;
+	acpi_driver_data(device) = hotkey;
+	strcpy(acpi_device_name(device), ACPI_PCC_DEVICE_NAME);
+	strcpy(acpi_device_class(device), ACPI_PCC_CLASS);
+
+	status = acpi_install_notify_handler (
+			hotkey->handle,
+			ACPI_DEVICE_NOTIFY,
+			acpi_pcc_hotkey_notify,
+			hotkey);
+
+	if (ACPI_FAILURE(status)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error installing notify handler\n"));
+		kfree(hotkey);
+		return_VALUE(-ENODEV);
+	}
+
+	result = acpi_pcc_init_input(hotkey);
+	if (result) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error installing keyinput handler\n"));
+		kfree(hotkey);
+		return_VALUE(result);
+	}
+
+	return_VALUE(acpi_pcc_proc_init(device));
+}
+
+static int __init acpi_pcc_init(void)
+{
+	int result = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_init");
+
+	if (acpi_disabled) {
+		return_VALUE(-ENODEV);
+	}
+
+	result = acpi_bus_register_driver(&acpi_pcc_driver);
+	if (result < 0) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error registering hotkey driver\n"));
+		return_VALUE(-ENODEV);
+	}
+
+	return_VALUE(0);
+}
+
+module_init(acpi_pcc_init);
+
+static int acpi_pcc_hotkey_remove(struct acpi_device *device, int type)
+{
+	acpi_status		status = AE_OK;
+	struct acpi_hotkey	*hotkey = acpi_driver_data(device);
+
+	ACPI_FUNCTION_TRACE("acpi_pcc_hotkey_remove");
+
+	if (!device || !hotkey)
+		return_VALUE(-EINVAL);
+
+	if (hotkey->proc_dir_entry) {
+		acpi_pcc_remove_device(device, pcc_proc_items_sifr, hotkey->num_sifr);
+		acpi_pcc_remove_device(device, pcc_proc_items, sizeof(pcc_proc_items)/sizeof(ProcItem));
+		remove_proc_entry(PROC_PCC, acpi_root_dir);
+	}
+
+	status = acpi_remove_notify_handler(hotkey->handle,
+		    ACPI_DEVICE_NOTIFY, acpi_pcc_hotkey_notify);
+
+	if (ACPI_FAILURE(status))
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error removing notify handler\n"));
+
+	input_unregister_device(hotkey->input_dev);
+
+	kfree(hotkey);
+	return_VALUE(status == AE_OK);
+}
+
+static void __exit acpi_pcc_exit(void)
+{
+	ACPI_FUNCTION_TRACE("acpi_pcc_exit");
+
+	acpi_bus_unregister_driver(&acpi_pcc_driver);
+
+	return_VOID;
+}
+
+module_exit(acpi_pcc_exit);