/*
 * BK Id: SCCS/s.pmac_backlight.c 1.10 12/01/01 20:09:06 benh
 */
/*
 * Miscellaneous procedures for dealing with the PowerMac hardware.
 * Contains support for the backlight.
 * 
 *   Copyright (C) 2000 Benjamin Herrenschmidt
 *
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/stddef.h>
#include <linux/reboot.h>
#include <linux/nvram.h>
#include <asm/sections.h>
#include <asm/ptrace.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/nvram.h>
#include <asm/backlight.h>

#include <linux/adb.h>
#include <linux/pmu.h>

static struct backlight_controller *backlighter = NULL;
static void* backlighter_data = NULL;
static int backlight_autosave = 0;
static int backlight_level = BACKLIGHT_MAX;
static int backlight_enabled = 1;

void __pmac
register_backlight_controller(struct backlight_controller *ctrler, void *data, char *type)
{
	struct device_node* bk_node;
	char *prop;
	int valid = 0;

	bk_node = find_devices("backlight");
	
#ifdef CONFIG_ADB_PMU
	/* Special case for the old PowerBook since I can't test on it */
	backlight_autosave = machine_is_compatible("AAPL,3400/2400")
		|| machine_is_compatible("AAPL,3500");
	if ((backlight_autosave
	     || machine_is_compatible("AAPL,PowerBook1998")
	     || machine_is_compatible("PowerBook1,1"))
	    && !strcmp(type, "pmu"))
		valid = 1;
#endif
	if (bk_node) {
		prop = get_property(bk_node, "backlight-control", NULL);
		if (prop && !strncmp(prop, type, strlen(type)))
			valid = 1;
	}
	if (!valid)
		return;
	backlighter = ctrler;
	backlighter_data = data;
	
	if (bk_node && !backlight_autosave)
		prop = get_property(bk_node, "bklt", NULL);
	else
		prop = NULL;
	if (prop) {
		backlight_level = ((*prop)+1) >> 1;
		if (backlight_level > BACKLIGHT_MAX)
			backlight_level = BACKLIGHT_MAX;
	}
	
#ifdef CONFIG_ADB_PMU
	if (backlight_autosave) {
		struct adb_request req;
		pmu_request(&req, NULL, 2, 0xd9, 0);
		while (!req.complete)
			pmu_poll();
		backlight_level = req.reply[0] >> 4;
	}
#endif
	if (!backlighter->set_enable(1, backlight_level, data))
		backlight_enabled = 1;

	printk(KERN_INFO "Registered \"%s\" backlight controller, level: %d/15\n",
		type, backlight_level);
}

void __pmac
unregister_backlight_controller(struct backlight_controller *ctrler, void *data)
{
	/* We keep the current backlight level (for now) */
	if (ctrler == backlighter && data == backlighter_data)
		backlighter = NULL;
}

int __pmac
set_backlight_enable(int enable)
{
	int rc;
	
	if (!backlighter)
		return -ENODEV;
	rc = backlighter->set_enable(enable, backlight_level, backlighter_data);
	if (!rc)
		backlight_enabled = enable;
	return rc;
}

int __pmac
get_backlight_enable(void)
{
	if (!backlighter)
		return -ENODEV;
	return backlight_enabled;
}

int __pmac
set_backlight_level(int level)
{
	int rc = 0;
	
	if (!backlighter)
		return -ENODEV;
	if (level < BACKLIGHT_MIN)
		level = BACKLIGHT_OFF;
	if (level > BACKLIGHT_MAX)
		level = BACKLIGHT_MAX;
	if (backlight_enabled)
		rc = backlighter->set_level(level, backlighter_data);
	if (!rc)
		backlight_level = level;
	if (!rc && !backlight_autosave) {
		level <<=1;
		if (level & 0x10)
			level |= 0x01;
		// -- todo: save to property "bklt"
	}
	return rc;
}

int __pmac
get_backlight_level(void)
{
	if (!backlighter)
		return -ENODEV;
	return backlight_level;
}
