[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 void max8925_backlight_dt_init(struct platform_device *pdev)
{
	struct device_node *nproot = pdev->dev.parent->of_node, *np;
	struct max8925_backlight_pdata *pdata;
	u32 val;

	if (!nproot || !IS_ENABLED(CONFIG_OF))
		return;

	pdata = devm_kzalloc(&pdev->dev,
			     sizeof(struct max8925_backlight_pdata),
			     GFP_KERNEL);
	if (!pdata)
		return;

	np = of_find_node_by_name(nproot, "backlight");
	if (!np) {
		dev_err(&pdev->dev, "failed to find backlight node\n");
		return;
	}

	if (!of_property_read_u32(np, "maxim,max8925-dual-string", &val))
		pdata->dual_string = val;

	pdev->dev.platform_data = pdata;
}

static int max8925_backlight_probe(struct platform_device *pdev)
{
	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
	struct max8925_backlight_pdata *pdata;
	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");
		return -ENXIO;
	}
	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");
		return -ENXIO;
	}
	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 = devm_backlight_device_register(&pdev->dev, "max8925-backlight",
					&pdev->dev, data,
					&max8925_backlight_ops, &props);
	if (IS_ERR(bl)) {
		dev_err(&pdev->dev, "failed to register backlight\n");
		return PTR_ERR(bl);
	}
	bl->props.brightness = MAX_BRIGHTNESS;

	platform_set_drvdata(pdev, bl);

	value = 0;
	if (!pdev->dev.platform_data)
		max8925_backlight_dt_init(pdev);

	pdata = pdev->dev.platform_data;
	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)
		return ret;
	backlight_update_status(bl);
	return 0;
}

static struct platform_driver max8925_backlight_driver = {
	.driver		= {
		.name	= "max8925-backlight",
	},
	.probe		= max8925_backlight_probe,
};

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
515c0967	104	static void max8925_backlight_dt_init(struct platform_device *pdev)
47ec340c QX	105	{
47ec340c QX	106	struct device_node nproot = pdev->dev.parent->of_node, np;
515c0967 OJ	107	struct max8925_backlight_pdata *pdata;
	108	u32 val;
	109
	110	if (!nproot \|\| !IS_ENABLED(CONFIG_OF))
	111	return;
	112
	113	pdata = devm_kzalloc(&pdev->dev,
	114	sizeof(struct max8925_backlight_pdata),
	115	GFP_KERNEL);
	116	if (!pdata)
	117	return;
47ec340c	118
47ec340c QX	119	np = of_find_node_by_name(nproot, "backlight");
	120	if (!np) {
	121	dev_err(&pdev->dev, "failed to find backlight node\n");
515c0967	122	return;
47ec340c QX	123	}
47ec340c QX	124
515c0967 OJ	125	if (!of_property_read_u32(np, "maxim,max8925-dual-string", &val))
	126	pdata->dual_string = val;
	127
	128	pdev->dev.platform_data = pdata;
47ec340c	129	}
47ec340c	130
1b9e450d	131	static int max8925_backlight_probe(struct platform_device *pdev)
4f811ef0 HZ	132	{
4f811ef0 HZ	133	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
515c0967	134	struct max8925_backlight_pdata *pdata;
4f811ef0 HZ	135	struct max8925_backlight_data *data;
4f811ef0 HZ	136	struct backlight_device *bl;
a19a6ee6	137	struct backlight_properties props;
4f811ef0	138	struct resource *res;
4f811ef0	139	unsigned char value;
63b501e2	140	int ret = 0;
4f811ef0	141
ce969228 JL	142	data = devm_kzalloc(&pdev->dev, sizeof(struct max8925_backlight_data),
ce969228 JL	143	GFP_KERNEL);
4f811ef0 HZ	144	if (data == NULL)
4f811ef0 HZ	145	return -ENOMEM;
63b501e2 HZ	146
	147	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
	148	if (!res) {
	149	dev_err(&pdev->dev, "No REG resource for mode control!\n");
2c114cb4	150	return -ENXIO;
63b501e2 HZ	151	}
	152	data->reg_mode_cntl = res->start;
	153	res = platform_get_resource(pdev, IORESOURCE_REG, 1);
	154	if (!res) {
	155	dev_err(&pdev->dev, "No REG resource for control!\n");
2c114cb4	156	return -ENXIO;
63b501e2 HZ	157	}
	158	data->reg_cntl = res->start;
	159
4f811ef0 HZ	160	data->chip = chip;
	161	data->current_brightness = 0;
	162
a19a6ee6	163	memset(&props, 0, sizeof(struct backlight_properties));
bb7ca747	164	props.type = BACKLIGHT_RAW;
a19a6ee6	165	props.max_brightness = MAX_BRIGHTNESS;
18d9dbce JH	166	bl = devm_backlight_device_register(&pdev->dev, "max8925-backlight",
18d9dbce JH	167	&pdev->dev, data,
a19a6ee6	168	&max8925_backlight_ops, &props);
4f811ef0 HZ	169	if (IS_ERR(bl)) {
4f811ef0 HZ	170	dev_err(&pdev->dev, "failed to register backlight\n");
2c114cb4	171	return PTR_ERR(bl);
4f811ef0	172	}
4f811ef0 HZ	173	bl->props.brightness = MAX_BRIGHTNESS;
	174
	175	platform_set_drvdata(pdev, bl);
	176
	177	value = 0;
515c0967 OJ	178	if (!pdev->dev.platform_data)
515c0967 OJ	179	max8925_backlight_dt_init(pdev);
47ec340c	180
515c0967	181	pdata = pdev->dev.platform_data;
63b501e2 HZ	182	if (pdata) {
	183	if (pdata->lxw_scl)
	184	value \|= (1 << 7);
	185	if (pdata->lxw_freq)
	186	value \|= (LWX_FREQ(pdata->lxw_freq) << 4);
	187	if (pdata->dual_string)
	188	value \|= (1 << 1);
	189	}
	190	ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 0xfe, value);
4f811ef0	191	if (ret < 0)
18d9dbce	192	return ret;
4f811ef0 HZ	193	backlight_update_status(bl);
4f811ef0 HZ	194	return 0;
4f811ef0 HZ	195	}
	196
	197	static struct platform_driver max8925_backlight_driver = {
	198	.driver = {
	199	.name = "max8925-backlight",
4f811ef0 HZ	200	},
4f811ef0 HZ	201	.probe = max8925_backlight_probe,
4f811ef0 HZ	202	};
4f811ef0 HZ	203
81178e02	204	module_platform_driver(max8925_backlight_driver);
4f811ef0 HZ	205
	206	MODULE_DESCRIPTION("Backlight Driver for Maxim MAX8925");
	207	MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
	208	MODULE_LICENSE("GPL");
	209	MODULE_ALIAS("platform:max8925-backlight");