/*

 * Backlight driver for Dialog Semiconductor DA9030/DA9034

 *

 * Copyright (C) 2008 Compulab, Ltd.

 * 	Mike Rapoport <mike@compulab.co.il>

 *

 * Copyright (C) 2006-2008 Marvell International Ltd.

 * 	Eric Miao <eric.miao@marvell.com>

 *

 * 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/kernel.h>

#include <linux/init.h>

#include <linux/platform_device.h>

#include <linux/fb.h>

#include <linux/backlight.h>

#include <linux/mfd/da903x.h>

#define DA9030_WLED_CONTROL	0x25

#define DA9030_WLED_CP_EN	(1 << 6)

#define DA9030_WLED_TRIM(x)	((x) & 0x7)

#define DA9034_WLED_CONTROL1	0x3C

#define DA9034_WLED_CONTROL2	0x3D

#define DA9034_WLED_BOOST_EN	(1 << 5)

#define DA9030_MAX_BRIGHTNESS	7

#define DA9034_MAX_BRIGHTNESS	0x7f

struct da903x_backlight_data {

	struct device *da903x_dev;

	int id;

	int current_brightness;

};

static int da903x_backlight_set(struct backlight_device *bl, int brightness)

{

	struct da903x_backlight_data *data = bl_get_data(bl);

	struct device *dev = data->da903x_dev;

	uint8_t val;

	int ret = 0;

	switch (data->id) {

	case DA9034_ID_WLED:

		ret = da903x_update(dev, DA9034_WLED_CONTROL1,

				brightness, 0x7f);

		if (ret)

			return ret;

		if (data->current_brightness && brightness == 0)

			ret = da903x_clr_bits(dev,

					DA9034_WLED_CONTROL2,

					DA9034_WLED_BOOST_EN);

		if (data->current_brightness == 0 && brightness)

			ret = da903x_set_bits(dev,

					DA9034_WLED_CONTROL2,

					DA9034_WLED_BOOST_EN);

		break;

	case DA9030_ID_WLED:

		val = DA9030_WLED_TRIM(brightness);

		val |= brightness ? DA9030_WLED_CP_EN : 0;

		ret = da903x_write(dev, DA9030_WLED_CONTROL, val);

		break;

	}

	if (ret)

		return ret;

	data->current_brightness = brightness;

	return 0;

}

static int da903x_backlight_update_status(struct backlight_device *bl)

{

	int brightness = bl->props.brightness;

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

		brightness = 0;

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

		brightness = 0;

	return da903x_backlight_set(bl, brightness);

}

static int da903x_backlight_get_brightness(struct backlight_device *bl)

{

	struct da903x_backlight_data *data = bl_get_data(bl);

	return data->current_brightness;

}

static struct backlight_ops da903x_backlight_ops = {

	.update_status	= da903x_backlight_update_status,

	.get_brightness	= da903x_backlight_get_brightness,

};

static int da903x_backlight_probe(struct platform_device *pdev)

{

	struct da903x_backlight_data *data;

	struct backlight_device *bl;

	int max_brightness;

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

	if (data == NULL)

		return -ENOMEM;

	switch (pdev->id) {

	case DA9030_ID_WLED:

		max_brightness = DA9030_MAX_BRIGHTNESS;

		break;

	case DA9034_ID_WLED:

		max_brightness = DA9034_MAX_BRIGHTNESS;

		break;

	default:

		dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",

				pdev->id);

		kfree(data);

		return -EINVAL;

	}

	data->id = pdev->id;

	data->da903x_dev = pdev->dev.parent;

	data->current_brightness = 0;

	bl = backlight_device_register(pdev->name, data->da903x_dev,

			data, &da903x_backlight_ops);

	if (IS_ERR(bl)) {

		dev_err(&pdev->dev, "failed to register backlight\n");

		kfree(data);

		return PTR_ERR(bl);

	}

	bl->props.max_brightness = max_brightness;

	bl->props.brightness = max_brightness;

	platform_set_drvdata(pdev, bl);

	backlight_update_status(bl);

	return 0;

}

static int da903x_backlight_remove(struct platform_device *pdev)

{

	struct backlight_device *bl = platform_get_drvdata(pdev);

	struct da903x_backlight_data *data = bl_get_data(bl);

	backlight_device_unregister(bl);

	kfree(data);

	return 0;

}

#ifdef CONFIG_PM

static int da903x_backlight_suspend(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct backlight_device *bl = platform_get_drvdata(pdev);

	return da903x_backlight_set(bl, 0);

}

static int da903x_backlight_resume(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct backlight_device *bl = platform_get_drvdata(pdev);

	backlight_update_status(bl);

	return 0;

}

static struct dev_pm_ops da903x_backlight_pm_ops = {

	.suspend	= da903x_backlight_suspend,

	.resume		= da903x_backlight_resume,

};

#endif

static struct platform_driver da903x_backlight_driver = {

	.driver		= {

		.name	= "da903x-backlight",

		.owner	= THIS_MODULE,

#ifdef CONFIG_PM

		.pm	= &da903x_backlight_pm_ops,

#endif

	},

	.probe		= da903x_backlight_probe,

	.remove		= da903x_backlight_remove,

};

static int __init da903x_backlight_init(void)

{

	return platform_driver_register(&da903x_backlight_driver);

}

module_init(da903x_backlight_init);

static void __exit da903x_backlight_exit(void)

{

	platform_driver_unregister(&da903x_backlight_driver);

}

module_exit(da903x_backlight_exit);

MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");

MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>"

	      "Mike Rapoport <mike@compulab.co.il>");

MODULE_LICENSE("GPL");

MODULE_ALIAS("platform:da903x-backlight");