/*

 *  Backlight Driver for the KB3886 Backlight

 *

 *  Copyright (c) 2007-2008 Claudio Nieder

 *

 *  Based on corgi_bl.c by Richard Purdie and kb3886 driver by Robert Woerle

 *

 *  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

 *  published by the Free Software Foundation.

 *

 */

#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/delay.h>

#include <linux/dmi.h>

#define KB3886_PARENT 0x64

#define KB3886_IO 0x60

#define KB3886_ADC_DAC_PWM 0xC4

#define KB3886_PWM0_WRITE 0x81

#define KB3886_PWM0_READ 0x41

static DEFINE_MUTEX(bl_mutex);

static void kb3886_bl_set_intensity(int intensity)

{

	mutex_lock(&bl_mutex);

	intensity = intensity&0xff;

	outb(KB3886_ADC_DAC_PWM, KB3886_PARENT);

	msleep(10);

	outb(KB3886_PWM0_WRITE, KB3886_IO);

	msleep(10);

	outb(intensity, KB3886_IO);

	mutex_unlock(&bl_mutex);

}

struct kb3886bl_machinfo {

	int max_intensity;

	int default_intensity;

	int limit_mask;

	void (*set_bl_intensity)(int intensity);

};

static struct kb3886bl_machinfo kb3886_bl_machinfo = {

	.max_intensity = 0xff,

	.default_intensity = 0xa0,

	.limit_mask = 0x7f,

	.set_bl_intensity = kb3886_bl_set_intensity,

};

static struct platform_device kb3886bl_device = {

	.name		= "kb3886-bl",

	.dev		= {

		.platform_data	= &kb3886_bl_machinfo,

	},

	.id		= -1,

};

static struct platform_device *devices[] __initdata = {

	&kb3886bl_device,

};

/*

 * Back to driver

 */

static int kb3886bl_intensity;

static struct backlight_device *kb3886_backlight_device;

static struct kb3886bl_machinfo *bl_machinfo;

static unsigned long kb3886bl_flags;

#define KB3886BL_SUSPENDED     0x01

static struct dmi_system_id __initdata kb3886bl_device_table[] = {

	{

		.ident = "Sahara Touch-iT",

		.matches = {

			DMI_MATCH(DMI_SYS_VENDOR, "SDV"),

			DMI_MATCH(DMI_PRODUCT_NAME, "iTouch T201"),

		},

	},

	{ }

};

static int kb3886bl_send_intensity(struct backlight_device *bd)

{

	int intensity = bd->props.brightness;

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

		intensity = 0;

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

		intensity = 0;

	if (kb3886bl_flags & KB3886BL_SUSPENDED)

		intensity = 0;

	bl_machinfo->set_bl_intensity(intensity);

	kb3886bl_intensity = intensity;

	return 0;

}

#ifdef CONFIG_PM

static int kb3886bl_suspend(struct platform_device *pdev, pm_message_t state)

{

	struct backlight_device *bd = platform_get_drvdata(pdev);

	kb3886bl_flags |= KB3886BL_SUSPENDED;

	backlight_update_status(bd);

	return 0;

}

static int kb3886bl_resume(struct platform_device *pdev)

{

	struct backlight_device *bd = platform_get_drvdata(pdev);

	kb3886bl_flags &= ~KB3886BL_SUSPENDED;

	backlight_update_status(bd);

	return 0;

}

#else

#define kb3886bl_suspend	NULL

#define kb3886bl_resume		NULL

#endif

static int kb3886bl_get_intensity(struct backlight_device *bd)

{

	return kb3886bl_intensity;

}

static struct backlight_ops kb3886bl_ops = {

	.get_brightness = kb3886bl_get_intensity,

	.update_status  = kb3886bl_send_intensity,

};

static int kb3886bl_probe(struct platform_device *pdev)

{

	struct kb3886bl_machinfo *machinfo = pdev->dev.platform_data;

	bl_machinfo = machinfo;

	if (!machinfo->limit_mask)

		machinfo->limit_mask = -1;

	kb3886_backlight_device = backlight_device_register("kb3886-bl",

		&pdev->dev, NULL, &kb3886bl_ops);

	if (IS_ERR(kb3886_backlight_device))

		return PTR_ERR(kb3886_backlight_device);

	platform_set_drvdata(pdev, kb3886_backlight_device);

	kb3886_backlight_device->props.max_brightness = machinfo->max_intensity;

	kb3886_backlight_device->props.power = FB_BLANK_UNBLANK;

	kb3886_backlight_device->props.brightness = machinfo->default_intensity;

	backlight_update_status(kb3886_backlight_device);

	return 0;

}

static int kb3886bl_remove(struct platform_device *pdev)

{

	struct backlight_device *bd = platform_get_drvdata(pdev);

	backlight_device_unregister(bd);

	return 0;

}

static struct platform_driver kb3886bl_driver = {

	.probe		= kb3886bl_probe,

	.remove		= kb3886bl_remove,

	.suspend	= kb3886bl_suspend,

	.resume		= kb3886bl_resume,

	.driver		= {

		.name	= "kb3886-bl",

	},

};

static int __init kb3886_init(void)

{

	if (!dmi_check_system(kb3886bl_device_table))

		return -ENODEV;

	platform_add_devices(devices, ARRAY_SIZE(devices));

	return platform_driver_register(&kb3886bl_driver);

}

static void __exit kb3886_exit(void)

{

	platform_driver_unregister(&kb3886bl_driver);

}

module_init(kb3886_init);

module_exit(kb3886_exit);

MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>");

MODULE_DESCRIPTION("Tabletkiosk Sahara Touch-iT Backlight Driver");

MODULE_LICENSE("GPL");

MODULE_ALIAS("dmi:*:svnSDV:pniTouchT201:*");