/*
 *  acpi_system.c - ACPI System Driver ($Revision: 63 $)
 *
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  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.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/proc_fs.h>
#include <linux/init.h>
#include <asm/uaccess.h>

#include <acpi/acpi_drivers.h>


#define _COMPONENT		ACPI_SYSTEM_COMPONENT
ACPI_MODULE_NAME		("acpi_system")

#define ACPI_SYSTEM_CLASS		"system"
#define ACPI_SYSTEM_DRIVER_NAME		"ACPI System Driver"
#define ACPI_SYSTEM_DEVICE_NAME		"System"
#define ACPI_SYSTEM_FILE_INFO		"info"
#define ACPI_SYSTEM_FILE_EVENT		"event"
#define ACPI_SYSTEM_FILE_DSDT		"dsdt"
#define ACPI_SYSTEM_FILE_FADT		"fadt"

extern FADT_DESCRIPTOR		acpi_fadt;

/* --------------------------------------------------------------------------
                              FS Interface (/proc)
   -------------------------------------------------------------------------- */

static int
acpi_system_read_info (
	char			*page,
	char			**start,
	off_t			off,
	int 			count,
	int 			*eof,
	void			*data)
{
	char			*p = page;
	int			size = 0;

	ACPI_FUNCTION_TRACE("acpi_system_read_info");

	if (off != 0)
		goto end;

	p += sprintf(p, "version:                 %x\n", ACPI_CA_VERSION);

end:
	size = (p - page);
	if (size <= off+count) *eof = 1;
	*start = page + off;
	size -= off;
	if (size>count) size = count;
	if (size<0) size = 0;

	return_VALUE(size);
}

static ssize_t acpi_system_read_dsdt (struct file*, char*, size_t, loff_t*);

static struct file_operations acpi_system_dsdt_ops = {
	.read =			acpi_system_read_dsdt,
};

static ssize_t
acpi_system_read_dsdt (
	struct file		*file,
	char			*buffer,
	size_t			count,
	loff_t			*ppos)
{
	acpi_status		status = AE_OK;
	struct acpi_buffer	dsdt = {ACPI_ALLOCATE_BUFFER, NULL};
	void			*data = 0;
	size_t			size = 0;

	ACPI_FUNCTION_TRACE("acpi_system_read_dsdt");

	status = acpi_get_table(ACPI_TABLE_DSDT, 1, &dsdt);
	if (ACPI_FAILURE(status))
		return_VALUE(-ENODEV);

	if (*ppos < dsdt.length) {
		data = dsdt.pointer + file->f_pos;
		size = dsdt.length - file->f_pos;
		if (size > count)
			size = count;
		if (copy_to_user(buffer, data, size)) {
			acpi_os_free(dsdt.pointer);
			return_VALUE(-EFAULT);
		}
	}

	acpi_os_free(dsdt.pointer);

	*ppos += size;

	return_VALUE(size);
}


static ssize_t acpi_system_read_fadt (struct file*, char*, size_t, loff_t*);

static struct file_operations acpi_system_fadt_ops = {
	.read =			acpi_system_read_fadt,
};

static ssize_t
acpi_system_read_fadt (
	struct file		*file,
	char			*buffer,
	size_t			count,
	loff_t			*ppos)
{
	acpi_status		status = AE_OK;
	struct acpi_buffer	fadt = {ACPI_ALLOCATE_BUFFER, NULL};
	void			*data = 0;
	size_t			size = 0;

	ACPI_FUNCTION_TRACE("acpi_system_read_fadt");

	status = acpi_get_table(ACPI_TABLE_FADT, 1, &fadt);
	if (ACPI_FAILURE(status))
		return_VALUE(-ENODEV);

	if (*ppos < fadt.length) {
		data = fadt.pointer + file->f_pos;
		size = fadt.length - file->f_pos;
		if (size > count)
			size = count;
		if (copy_to_user(buffer, data, size)) {
			acpi_os_free(fadt.pointer);
			return_VALUE(-EFAULT);
		}
	}

	acpi_os_free(fadt.pointer);

	*ppos += size;

	return_VALUE(size);
}


static int __init acpi_system_init (void)
{
	struct proc_dir_entry	*entry;
	int error = 0;
	char * name;

	ACPI_FUNCTION_TRACE("acpi_system_init");

	if (acpi_disabled)
		return_VALUE(0);

	/* 'info' [R] */
	name = ACPI_SYSTEM_FILE_INFO;
	entry = create_proc_read_entry(name,
		S_IRUGO, acpi_root_dir, acpi_system_read_info,NULL);
	if (!entry)
		goto Error;

	/* 'dsdt' [R] */
	name = ACPI_SYSTEM_FILE_DSDT;
	entry = create_proc_entry(name, S_IRUSR, acpi_root_dir);
	if (entry)
		entry->proc_fops = &acpi_system_dsdt_ops;
	else 
		goto Error;

	/* 'fadt' [R] */
	name = ACPI_SYSTEM_FILE_FADT;
	entry = create_proc_entry(name, S_IRUSR, acpi_root_dir);
	if (entry)
		entry->proc_fops = &acpi_system_fadt_ops;
	else
		goto Error;

 Done:
	return_VALUE(error);

 Error:
	ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 
			 "Unable to create '%s' proc fs entry\n", name));

	remove_proc_entry(ACPI_SYSTEM_FILE_FADT, acpi_root_dir);
	remove_proc_entry(ACPI_SYSTEM_FILE_DSDT, acpi_root_dir);
	remove_proc_entry(ACPI_SYSTEM_FILE_INFO, acpi_root_dir);

	error = -EFAULT;
	goto Done;
}


subsys_initcall(acpi_system_init);