/*

 * Copyright (c) Intel Corp. 2007.

 * All Rights Reserved.

 *

 * Intel funded Tungsten Graphics (http://www.tungstengraphics.com) to

 * develop this driver.

 *

 * This file is part of the Carillo Ranch video subsystem driver.

 * The Carillo Ranch video subsystem driver 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.

 *

 * The Carillo Ranch video subsystem driver 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 driver; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 *

 * Authors:

 *   Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>

 *   Alan Hourihane <alanh-at-tungstengraphics-dot-com>

 */

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/platform_device.h>

#include <linux/mutex.h>

#include <linux/fb.h>

#include <linux/backlight.h>

#include <linux/lcd.h>

#include <linux/pci.h>

/* The LVDS- and panel power controls sits on the

 * GPIO port of the ISA bridge.

 */

#define CRVML_DEVICE_LPC    0x27B8

#define CRVML_REG_GPIOBAR   0x48

#define CRVML_REG_GPIOEN    0x4C

#define CRVML_GPIOEN_BIT    (1 << 4)

#define CRVML_PANEL_PORT    0x38

#define CRVML_LVDS_ON       0x00000001

#define CRVML_PANEL_ON      0x00000002

#define CRVML_BACKLIGHT_OFF 0x00000004

/* The PLL Clock register sits on Host bridge */

#define CRVML_DEVICE_MCH   0x5001

#define CRVML_REG_MCHBAR   0x44

#define CRVML_REG_MCHEN    0x54

#define CRVML_MCHEN_BIT    (1 << 28)

#define CRVML_MCHMAP_SIZE  4096

#define CRVML_REG_CLOCK    0xc3c

#define CRVML_CLOCK_SHIFT  8

#define CRVML_CLOCK_MASK   0x00000f00

static struct pci_dev *lpc_dev;

static u32 gpio_bar;

struct cr_panel {

	struct backlight_device *cr_backlight_device;

	struct lcd_device *cr_lcd_device;

};

static int cr_backlight_set_intensity(struct backlight_device *bd)

{

	int intensity = bd->props.brightness;

	u32 addr = gpio_bar + CRVML_PANEL_PORT;

	u32 cur = inl(addr);

	if (bd->props.power == FB_BLANK_UNBLANK)

		intensity = FB_BLANK_UNBLANK;

	if (bd->props.fb_blank == FB_BLANK_UNBLANK)

		intensity = FB_BLANK_UNBLANK;

	if (bd->props.power == FB_BLANK_POWERDOWN)

		intensity = FB_BLANK_POWERDOWN;

	if (bd->props.fb_blank == FB_BLANK_POWERDOWN)

		intensity = FB_BLANK_POWERDOWN;

	if (intensity == FB_BLANK_UNBLANK) { /* FULL ON */

		cur &= ~CRVML_BACKLIGHT_OFF;

		outl(cur, addr);

	} else if (intensity == FB_BLANK_POWERDOWN) { /* OFF */

		cur |= CRVML_BACKLIGHT_OFF;

		outl(cur, addr);

	} /* anything else, don't bother */

	return 0;

}

static int cr_backlight_get_intensity(struct backlight_device *bd)

{

	u32 addr = gpio_bar + CRVML_PANEL_PORT;

	u32 cur = inl(addr);

	u8 intensity;

	if (cur & CRVML_BACKLIGHT_OFF)

		intensity = FB_BLANK_POWERDOWN;

	else

		intensity = FB_BLANK_UNBLANK;

	return intensity;

}

static struct backlight_ops cr_backlight_ops = {

	.get_brightness = cr_backlight_get_intensity,

	.update_status = cr_backlight_set_intensity,

};

static void cr_panel_on(void)

{

	u32 addr = gpio_bar + CRVML_PANEL_PORT;

	u32 cur = inl(addr);

	if (!(cur & CRVML_PANEL_ON)) {

		/* Make sure LVDS controller is down. */

		if (cur & 0x00000001) {

			cur &= ~CRVML_LVDS_ON;

			outl(cur, addr);

		}

		/* Power up Panel */

		schedule_timeout(HZ / 10);

		cur |= CRVML_PANEL_ON;

		outl(cur, addr);

	}

	/* Power up LVDS controller */

	if (!(cur & CRVML_LVDS_ON)) {

		schedule_timeout(HZ / 10);

		outl(cur | CRVML_LVDS_ON, addr);

	}

}

static void cr_panel_off(void)

{

	u32 addr = gpio_bar + CRVML_PANEL_PORT;

	u32 cur = inl(addr);

	/* Power down LVDS controller first to avoid high currents */

	if (cur & CRVML_LVDS_ON) {

		cur &= ~CRVML_LVDS_ON;

		outl(cur, addr);

	}

	if (cur & CRVML_PANEL_ON) {

		schedule_timeout(HZ / 10);

		outl(cur & ~CRVML_PANEL_ON, addr);

	}

}

static int cr_lcd_set_power(struct lcd_device *ld, int power)

{

	if (power == FB_BLANK_UNBLANK)

		cr_panel_on();

	if (power == FB_BLANK_POWERDOWN)

		cr_panel_off();

	return 0;

}

static struct lcd_ops cr_lcd_ops = {

	.set_power = cr_lcd_set_power,

};

static int cr_backlight_probe(struct platform_device *pdev)

{

	struct backlight_device *bdp;

	struct lcd_device *ldp;

	struct cr_panel *crp;

	u8 dev_en;

	lpc_dev = pci_get_device(PCI_VENDOR_ID_INTEL,

					CRVML_DEVICE_LPC, NULL);

	if (!lpc_dev) {

		printk("INTEL CARILLO RANCH LPC not found.\n");

		return -ENODEV;

	}

	pci_read_config_byte(lpc_dev, CRVML_REG_GPIOEN, &dev_en);

	if (!(dev_en & CRVML_GPIOEN_BIT)) {

		printk(KERN_ERR

		       "Carillo Ranch GPIO device was not enabled.\n");

		pci_dev_put(lpc_dev);

		return -ENODEV;

	}

	bdp = backlight_device_register("cr-backlight",

					&pdev->dev, NULL, &cr_backlight_ops);

	if (IS_ERR(bdp)) {

		pci_dev_put(lpc_dev);

		return PTR_ERR(bdp);

	}

	ldp = lcd_device_register("cr-lcd", &pdev->dev, NULL, &cr_lcd_ops);

	if (IS_ERR(ldp)) {

		backlight_device_unregister(bdp);

		pci_dev_put(lpc_dev);

		return PTR_ERR(bdp);

	}

	pci_read_config_dword(lpc_dev, CRVML_REG_GPIOBAR,

			      &gpio_bar);

	gpio_bar &= ~0x3F;

	crp = kzalloc(sizeof(*crp), GFP_KERNEL);

	if (!crp) {

		lcd_device_unregister(ldp);

		backlight_device_unregister(bdp);

		pci_dev_put(lpc_dev);

		return -ENOMEM;

	}

	crp->cr_backlight_device = bdp;

	crp->cr_lcd_device = ldp;

	crp->cr_backlight_device->props.power = FB_BLANK_UNBLANK;

	crp->cr_backlight_device->props.brightness = 0;

	crp->cr_backlight_device->props.max_brightness = 0;

	cr_backlight_set_intensity(crp->cr_backlight_device);

	cr_lcd_set_power(crp->cr_lcd_device, FB_BLANK_UNBLANK);

	platform_set_drvdata(pdev, crp);

	return 0;

}

static int cr_backlight_remove(struct platform_device *pdev)

{

	struct cr_panel *crp = platform_get_drvdata(pdev);

	crp->cr_backlight_device->props.power = FB_BLANK_POWERDOWN;

	crp->cr_backlight_device->props.brightness = 0;

	crp->cr_backlight_device->props.max_brightness = 0;

	cr_backlight_set_intensity(crp->cr_backlight_device);

	cr_lcd_set_power(crp->cr_lcd_device, FB_BLANK_POWERDOWN);

	backlight_device_unregister(crp->cr_backlight_device);

	lcd_device_unregister(crp->cr_lcd_device);

	pci_dev_put(lpc_dev);

	return 0;

}

static struct platform_driver cr_backlight_driver = {

	.probe = cr_backlight_probe,

	.remove = cr_backlight_remove,

	.driver = {

		   .name = "cr_backlight",

		   },

};

static struct platform_device *crp;

static int __init cr_backlight_init(void)

{

	int ret = platform_driver_register(&cr_backlight_driver);

	if (ret)

		return ret;

	crp = platform_device_register_simple("cr_backlight", -1, NULL, 0);

	if (IS_ERR(crp)) {

		platform_driver_unregister(&cr_backlight_driver);

		return PTR_ERR(crp);

	}

	printk("Carillo Ranch Backlight Driver Initialized.\n");

	return 0;

}

static void __exit cr_backlight_exit(void)

{

	platform_device_unregister(crp);

	platform_driver_unregister(&cr_backlight_driver);

}

module_init(cr_backlight_init);

module_exit(cr_backlight_exit);

MODULE_AUTHOR("Tungsten Graphics Inc.");

MODULE_DESCRIPTION("Carillo Ranch Backlight Driver");

MODULE_LICENSE("GPL");