/*
 * pommed - Apple laptops hotkeys handler daemon
 *
 * MacBook Backlight Control (Intel GMA950 & GMA965)
 *
 * Copyright (C) 2006-2007 Ryan Lortie <desrt@desrt.ca>
 * Copyright (C) 2006-2007 Julien BLACHE <jb@jblache.org>
 *  + Adapted for pommed
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 *
 * The GMA950 has a backlight control register at offset 0x00061254 in its
 * PCI memory space (512K region):
 *  - bits 0-15 represent the backlight value
 *  - bits 16 indicates legacy mode is in use when set
 *  - bits 17-31 hold the max backlight value << 1
 *
 * Bit 16 indicates whether the backlight control should be used in legacy
 * mode or not. This bit is 0 on MacBooks, indicating native mode should be
 * used. This is the only method supported here.
 *
 *
 * The GMA965 is slightly different; the backlight control register is at
 * offset 0x00061250 in its PCI memory space (first 512K in the 1M region):
 *  - bits 0-15 represent the backlight value
 *  - bits 16-31 hold the max backlight value
 *  - bit 30 indicates legacy mode is in use when set
 *
 *
 * For BOTH cards, the register for the backlight value is at offset 0x00061254.
 *
 *
 * For both cards, in the code below, max value and current value are expressed
 * on 15 bits; the values are shifted as appropriate when appropriate.
 */

#include <stdio.h>
#include <sys/io.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#include <syslog.h>

#include <errno.h>

#include <pci/pci.h>

#include "../pommed.h"
#include "../conffile.h"
#include "../lcd_backlight.h"
#include "../dbus.h"


static unsigned int GMA950_BACKLIGHT_MAX;

static int fd = -1;
static char *memory = NULL;
static char sysfs_resource[64];
static long length = 0;

#define REGISTER_OFFSET           0x00061254

#define GMA950_LEGACY_MODE        (1 << 16)
#define GMA950_CONTROL_REGISTER   0x00061254

#define GMA965_LEGACY_MODE        (1 << 30)
#define GMA965_CONTROL_REGISTER   0x00061250

static inline unsigned int
readl(const volatile void *addr)
{
  return *(volatile unsigned int*) addr;
}

static inline void
writel(unsigned int b, volatile void *addr)
{
  *(volatile unsigned int*) addr = b;
}

#define INREG(addr)     readl(memory+addr)
#define OUTREG(addr,val)    writel(val, memory+addr)


static unsigned int
gma950_backlight_get(void)
{
  return (INREG(REGISTER_OFFSET) >> 1) & 0x7fff;
}

static unsigned int
gma950_backlight_get_max(void)
{
  return (INREG(REGISTER_OFFSET) >> 17);
}

static void
gma950_backlight_set(unsigned int value)
{
  OUTREG(REGISTER_OFFSET, (GMA950_BACKLIGHT_MAX << 17) | (value << 1));
}


static int
gma950_backlight_map(void)
{
  return 0;
}

static void
gma950_backlight_unmap(void)
{
}


void
gma950_backlight_step(int dir)
{

}


void
gma950_backlight_toggle(int lvl)
{

}


/*
 * We are hardware-dependent for GMA950_BACKLIGHT_MAX,
 * so here _fix_config() is static and called at probe time.
 */
static void
gma950_backlight_fix_config(void)
{

}


#define PCI_ID_VENDOR_INTEL      0x8086
#define PCI_ID_PRODUCT_GMA950    0x27A2
#define PCI_ID_PRODUCT_GMA965    0x2A02

/* Look for an Intel GMA950 or GMA965 */
int
gma950_backlight_probe(void)
{
  return 0;
}