[deliverable/linux.git] / drivers / video / backlight / max8925_bl.c

/*
 * Backlight driver for Maxim MAX8925
 *
 * Copyright (C) 2009 Marvell International Ltd.
 *      Haojian Zhuang <haojian.zhuang@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/init.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/fb.h>
#include <linux/i2c.h>
#include <linux/backlight.h>
#include <linux/mfd/max8925.h>
#include <linux/slab.h>
#include <linux/module.h>

#define MAX_BRIGHTNESS		(0xff)
#define MIN_BRIGHTNESS		(0)

#define LWX_FREQ(x)		(((x - 601) / 100) & 0x7)

struct max8925_backlight_data {
	struct max8925_chip	*chip;

	int	current_brightness;
	int	reg_mode_cntl;
	int	reg_cntl;
};

static int max8925_backlight_set(struct backlight_device *bl, int brightness)
{
	struct max8925_backlight_data *data = bl_get_data(bl);
	struct max8925_chip *chip = data->chip;
	unsigned char value;
	int ret;

	if (brightness > MAX_BRIGHTNESS)
		value = MAX_BRIGHTNESS;
	else
		value = brightness;

	ret = max8925_reg_write(chip->i2c, data->reg_cntl, value);
	if (ret < 0)
		goto out;

	if (!data->current_brightness && brightness)
		/* enable WLED output */
		ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 1, 1);
	else if (!brightness)
		/* disable WLED output */
		ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 1, 0);
	if (ret < 0)
		goto out;
	dev_dbg(chip->dev, "set brightness %d\n", value);
	data->current_brightness = value;
	return 0;
out:
	dev_dbg(chip->dev, "set brightness %d failure with return value:%d\n",
		value, ret);
	return ret;
}

static int max8925_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;

	if (bl->props.state & BL_CORE_SUSPENDED)
		brightness = 0;

	return max8925_backlight_set(bl, brightness);
}

static int max8925_backlight_get_brightness(struct backlight_device *bl)
{
	struct max8925_backlight_data *data = bl_get_data(bl);
	struct max8925_chip *chip = data->chip;
	int ret;

	ret = max8925_reg_read(chip->i2c, data->reg_cntl);
	if (ret < 0)
		return -EINVAL;
	data->current_brightness = ret;
	dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
	return ret;
}

static const struct backlight_ops max8925_backlight_ops = {
	.options	= BL_CORE_SUSPENDRESUME,
	.update_status	= max8925_backlight_update_status,
	.get_brightness	= max8925_backlight_get_brightness,
};

static int __devinit max8925_backlight_probe(struct platform_device *pdev)
{
	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
	struct max8925_backlight_pdata *pdata = pdev->dev.platform_data;
	struct max8925_backlight_data *data;
	struct backlight_device *bl;
	struct backlight_properties props;
	struct resource *res;
	unsigned char value;
	int ret = 0;

	data = devm_kzalloc(&pdev->dev, sizeof(struct max8925_backlight_data),
			    GFP_KERNEL);
	if (data == NULL)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
	if (!res) {
		dev_err(&pdev->dev, "No REG resource for mode control!\n");
		ret = -ENXIO;
		goto out;
	}
	data->reg_mode_cntl = res->start;
	res = platform_get_resource(pdev, IORESOURCE_REG, 1);
	if (!res) {
		dev_err(&pdev->dev, "No REG resource for control!\n");
		ret = -ENXIO;
		goto out;
	}
	data->reg_cntl = res->start;

	data->chip = chip;
	data->current_brightness = 0;

	memset(&props, 0, sizeof(struct backlight_properties));
	props.type = BACKLIGHT_RAW;
	props.max_brightness = MAX_BRIGHTNESS;
	bl = backlight_device_register("max8925-backlight", &pdev->dev, data,
					&max8925_backlight_ops, &props);
	if (IS_ERR(bl)) {
		dev_err(&pdev->dev, "failed to register backlight\n");
		ret = PTR_ERR(bl);
		goto out;
	}
	bl->props.brightness = MAX_BRIGHTNESS;

	platform_set_drvdata(pdev, bl);

	value = 0;
	if (pdata) {
		if (pdata->lxw_scl)
			value |= (1 << 7);
		if (pdata->lxw_freq)
			value |= (LWX_FREQ(pdata->lxw_freq) << 4);
		if (pdata->dual_string)
			value |= (1 << 1);
	}
	ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 0xfe, value);
	if (ret < 0)
		goto out_brt;

	backlight_update_status(bl);
	return 0;
out_brt:
	backlight_device_unregister(bl);
out:
	devm_kfree(&pdev->dev, data);
	return ret;
}

static int __devexit max8925_backlight_remove(struct platform_device *pdev)
{
	struct backlight_device *bl = platform_get_drvdata(pdev);

	backlight_device_unregister(bl);
	return 0;
}

static struct platform_driver max8925_backlight_driver = {
	.driver		= {
		.name	= "max8925-backlight",
		.owner	= THIS_MODULE,
	},
	.probe		= max8925_backlight_probe,
	.remove		= __devexit_p(max8925_backlight_remove),
};

module_platform_driver(max8925_backlight_driver);

MODULE_DESCRIPTION("Backlight Driver for Maxim MAX8925");
MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:max8925-backlight");
Commit	Line	Data
4f811ef0 HZ	1	/*
	2	* Backlight driver for Maxim MAX8925
	3	*
	4	* Copyright (C) 2009 Marvell International Ltd.
	5	* Haojian Zhuang <haojian.zhuang@marvell.com>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11
	12	#include <linux/init.h>
	13	#include <linux/kernel.h>
	14	#include <linux/platform_device.h>
	15	#include <linux/fb.h>
	16	#include <linux/i2c.h>
	17	#include <linux/backlight.h>
	18	#include <linux/mfd/max8925.h>
5a0e3ad6	19	#include <linux/slab.h>
355b200b	20	#include <linux/module.h>
4f811ef0 HZ	21
	22	#define MAX_BRIGHTNESS (0xff)
	23	#define MIN_BRIGHTNESS (0)
	24
	25	#define LWX_FREQ(x) (((x - 601) / 100) & 0x7)
	26
	27	struct max8925_backlight_data {
	28	struct max8925_chip *chip;
	29
63b501e2 HZ	30	int current_brightness;
	31	int reg_mode_cntl;
	32	int reg_cntl;
4f811ef0 HZ	33	};
	34
	35	static int max8925_backlight_set(struct backlight_device *bl, int brightness)
	36	{
	37	struct max8925_backlight_data *data = bl_get_data(bl);
	38	struct max8925_chip *chip = data->chip;
	39	unsigned char value;
	40	int ret;
	41
	42	if (brightness > MAX_BRIGHTNESS)
	43	value = MAX_BRIGHTNESS;
	44	else
	45	value = brightness;
	46
63b501e2	47	ret = max8925_reg_write(chip->i2c, data->reg_cntl, value);
4f811ef0 HZ	48	if (ret < 0)
	49	goto out;
	50
	51	if (!data->current_brightness && brightness)
	52	/* enable WLED output */
63b501e2	53	ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 1, 1);
4f811ef0 HZ	54	else if (!brightness)
4f811ef0 HZ	55	/* disable WLED output */
63b501e2	56	ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 1, 0);
4f811ef0 HZ	57	if (ret < 0)
	58	goto out;
	59	dev_dbg(chip->dev, "set brightness %d\n", value);
	60	data->current_brightness = value;
	61	return 0;
	62	out:
	63	dev_dbg(chip->dev, "set brightness %d failure with return value:%d\n",
	64	value, ret);
	65	return ret;
	66	}
	67
	68	static int max8925_backlight_update_status(struct backlight_device *bl)
	69	{
	70	int brightness = bl->props.brightness;
	71
	72	if (bl->props.power != FB_BLANK_UNBLANK)
	73	brightness = 0;
	74
	75	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
	76	brightness = 0;
	77
	78	if (bl->props.state & BL_CORE_SUSPENDED)
	79	brightness = 0;
	80
	81	return max8925_backlight_set(bl, brightness);
	82	}
	83
	84	static int max8925_backlight_get_brightness(struct backlight_device *bl)
	85	{
	86	struct max8925_backlight_data *data = bl_get_data(bl);
	87	struct max8925_chip *chip = data->chip;
	88	int ret;
	89
63b501e2	90	ret = max8925_reg_read(chip->i2c, data->reg_cntl);
4f811ef0 HZ	91	if (ret < 0)
	92	return -EINVAL;
	93	data->current_brightness = ret;
	94	dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
	95	return ret;
	96	}
	97
acc2472e	98	static const struct backlight_ops max8925_backlight_ops = {
4f811ef0 HZ	99	.options = BL_CORE_SUSPENDRESUME,
	100	.update_status = max8925_backlight_update_status,
	101	.get_brightness = max8925_backlight_get_brightness,
	102	};
	103
	104	static int __devinit max8925_backlight_probe(struct platform_device *pdev)
	105	{
	106	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
63b501e2	107	struct max8925_backlight_pdata *pdata = pdev->dev.platform_data;
4f811ef0 HZ	108	struct max8925_backlight_data *data;
4f811ef0 HZ	109	struct backlight_device *bl;
a19a6ee6	110	struct backlight_properties props;
4f811ef0	111	struct resource *res;
4f811ef0	112	unsigned char value;
63b501e2	113	int ret = 0;
4f811ef0	114
ce969228 JL	115	data = devm_kzalloc(&pdev->dev, sizeof(struct max8925_backlight_data),
ce969228 JL	116	GFP_KERNEL);
4f811ef0 HZ	117	if (data == NULL)
4f811ef0 HZ	118	return -ENOMEM;
63b501e2 HZ	119
	120	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
	121	if (!res) {
	122	dev_err(&pdev->dev, "No REG resource for mode control!\n");
	123	ret = -ENXIO;
	124	goto out;
	125	}
	126	data->reg_mode_cntl = res->start;
	127	res = platform_get_resource(pdev, IORESOURCE_REG, 1);
	128	if (!res) {
	129	dev_err(&pdev->dev, "No REG resource for control!\n");
	130	ret = -ENXIO;
	131	goto out;
	132	}
	133	data->reg_cntl = res->start;
	134
4f811ef0 HZ	135	data->chip = chip;
	136	data->current_brightness = 0;
	137
a19a6ee6	138	memset(&props, 0, sizeof(struct backlight_properties));
bb7ca747	139	props.type = BACKLIGHT_RAW;
a19a6ee6	140	props.max_brightness = MAX_BRIGHTNESS;
63b501e2	141	bl = backlight_device_register("max8925-backlight", &pdev->dev, data,
a19a6ee6	142	&max8925_backlight_ops, &props);
4f811ef0 HZ	143	if (IS_ERR(bl)) {
4f811ef0 HZ	144	dev_err(&pdev->dev, "failed to register backlight\n");
63b501e2 HZ	145	ret = PTR_ERR(bl);
63b501e2 HZ	146	goto out;
4f811ef0	147	}
4f811ef0 HZ	148	bl->props.brightness = MAX_BRIGHTNESS;
	149
	150	platform_set_drvdata(pdev, bl);
	151
	152	value = 0;
63b501e2 HZ	153	if (pdata) {
	154	if (pdata->lxw_scl)
	155	value \|= (1 << 7);
	156	if (pdata->lxw_freq)
	157	value \|= (LWX_FREQ(pdata->lxw_freq) << 4);
	158	if (pdata->dual_string)
	159	value \|= (1 << 1);
	160	}
	161	ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 0xfe, value);
4f811ef0	162	if (ret < 0)
63b501e2	163	goto out_brt;
4f811ef0 HZ	164
	165	backlight_update_status(bl);
	166	return 0;
63b501e2	167	out_brt:
146e10a8	168	backlight_device_unregister(bl);
63b501e2 HZ	169	out:
63b501e2 HZ	170	devm_kfree(&pdev->dev, data);
4f811ef0 HZ	171	return ret;
	172	}
	173
	174	static int __devexit max8925_backlight_remove(struct platform_device *pdev)
	175	{
	176	struct backlight_device *bl = platform_get_drvdata(pdev);
4f811ef0 HZ	177
4f811ef0 HZ	178	backlight_device_unregister(bl);
4f811ef0 HZ	179	return 0;
	180	}
	181
	182	static struct platform_driver max8925_backlight_driver = {
	183	.driver = {
	184	.name = "max8925-backlight",
	185	.owner = THIS_MODULE,
	186	},
	187	.probe = max8925_backlight_probe,
	188	.remove = __devexit_p(max8925_backlight_remove),
	189	};
	190
81178e02	191	module_platform_driver(max8925_backlight_driver);
4f811ef0 HZ	192
	193	MODULE_DESCRIPTION("Backlight Driver for Maxim MAX8925");
	194	MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
	195	MODULE_LICENSE("GPL");
	196	MODULE_ALIAS("platform:max8925-backlight");