[mirror_ubuntu-artful-kernel.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>

#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;
};

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, MAX8925_WLED_CNTL, value);
	if (ret < 0)
		goto out;

	if (!data->current_brightness && brightness)
		/* enable WLED output */
		ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 1, 1);
	else if (!brightness)
		/* disable WLED output */
		ret = max8925_set_bits(chip->i2c, MAX8925_WLED_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, MAX8925_WLED_CNTL);
	if (ret < 0)
		return -EINVAL;
	data->current_brightness = ret;
	dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
	return ret;
}

static 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_platform_data *max8925_pdata;
	struct max8925_backlight_pdata *pdata = NULL;
	struct max8925_backlight_data *data;
	struct backlight_device *bl;
	struct backlight_properties props;
	struct resource *res;
	char name[MAX8925_NAME_SIZE];
	unsigned char value;
	int ret;

	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	if (res == NULL) {
		dev_err(&pdev->dev, "No I/O resource!\n");
		return -EINVAL;
	}

	if (pdev->dev.parent->platform_data) {
		max8925_pdata = pdev->dev.parent->platform_data;
		pdata = max8925_pdata->backlight;
	}

	if (!pdata) {
		dev_err(&pdev->dev, "platform data isn't assigned to "
			"backlight\n");
		return -EINVAL;
	}

	data = kzalloc(sizeof(struct max8925_backlight_data), GFP_KERNEL);
	if (data == NULL)
		return -ENOMEM;
	strncpy(name, res->name, MAX8925_NAME_SIZE);
	data->chip = chip;
	data->current_brightness = 0;

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

	platform_set_drvdata(pdev, bl);

	value = 0;
	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, MAX8925_WLED_MODE_CNTL, 0xfe, value);
	if (ret < 0)
		goto out;

	backlight_update_status(bl);
	return 0;
out:
	kfree(data);
	return ret;
}

static int __devexit max8925_backlight_remove(struct platform_device *pdev)
{
	struct backlight_device *bl = platform_get_drvdata(pdev);
	struct max8925_backlight_data *data = bl_get_data(bl);

	backlight_device_unregister(bl);
	kfree(data);
	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),
};

static int __init max8925_backlight_init(void)
{
	return platform_driver_register(&max8925_backlight_driver);
}
module_init(max8925_backlight_init);

static void __exit max8925_backlight_exit(void)
{
	platform_driver_unregister(&max8925_backlight_driver);
};
module_exit(max8925_backlight_exit);

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>
4f811ef0 HZ	20
	21	#define MAX_BRIGHTNESS (0xff)
	22	#define MIN_BRIGHTNESS (0)
	23
	24	#define LWX_FREQ(x) (((x - 601) / 100) & 0x7)
	25
	26	struct max8925_backlight_data {
	27	struct max8925_chip *chip;
	28
	29	int current_brightness;
	30	};
	31
	32	static int max8925_backlight_set(struct backlight_device *bl, int brightness)
	33	{
	34	struct max8925_backlight_data *data = bl_get_data(bl);
	35	struct max8925_chip *chip = data->chip;
	36	unsigned char value;
	37	int ret;
	38
	39	if (brightness > MAX_BRIGHTNESS)
	40	value = MAX_BRIGHTNESS;
	41	else
	42	value = brightness;
	43
	44	ret = max8925_reg_write(chip->i2c, MAX8925_WLED_CNTL, value);
	45	if (ret < 0)
	46	goto out;
	47
	48	if (!data->current_brightness && brightness)
	49	/* enable WLED output */
	50	ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 1, 1);
	51	else if (!brightness)
	52	/* disable WLED output */
	53	ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 1, 0);
	54	if (ret < 0)
	55	goto out;
	56	dev_dbg(chip->dev, "set brightness %d\n", value);
	57	data->current_brightness = value;
	58	return 0;
	59	out:
	60	dev_dbg(chip->dev, "set brightness %d failure with return value:%d\n",
	61	value, ret);
	62	return ret;
	63	}
	64
	65	static int max8925_backlight_update_status(struct backlight_device *bl)
	66	{
	67	int brightness = bl->props.brightness;
	68
	69	if (bl->props.power != FB_BLANK_UNBLANK)
	70	brightness = 0;
	71
	72	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
	73	brightness = 0;
	74
	75	if (bl->props.state & BL_CORE_SUSPENDED)
	76	brightness = 0;
	77
	78	return max8925_backlight_set(bl, brightness);
	79	}
	80
	81	static int max8925_backlight_get_brightness(struct backlight_device *bl)
	82	{
	83	struct max8925_backlight_data *data = bl_get_data(bl);
84	struct max8925_chip *chip = data->chip;
85	int ret;
86
87	ret = max8925_reg_read(chip->i2c, MAX8925_WLED_CNTL);
88	if (ret < 0)
89	return -EINVAL;
90	data->current_brightness = ret;
91	dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
92	return ret;
93	}
94
95	static struct backlight_ops max8925_backlight_ops = {
96	.options = BL_CORE_SUSPENDRESUME,
97	.update_status = max8925_backlight_update_status,
98	.get_brightness = max8925_backlight_get_brightness,
99	};
100
101	static int __devinit max8925_backlight_probe(struct platform_device *pdev)
102	{
103	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
104	struct max8925_platform_data *max8925_pdata;
105	struct max8925_backlight_pdata *pdata = NULL;
106	struct max8925_backlight_data *data;
107	struct backlight_device *bl;
a19a6ee6	108	struct backlight_properties props;
4f811ef0 HZ	109	struct resource *res;
	110	char name[MAX8925_NAME_SIZE];
	111	unsigned char value;
	112	int ret;
	113
	114	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	115	if (res == NULL) {
	116	dev_err(&pdev->dev, "No I/O resource!\n");
	117	return -EINVAL;
	118	}
	119
	120	if (pdev->dev.parent->platform_data) {
	121	max8925_pdata = pdev->dev.parent->platform_data;
	122	pdata = max8925_pdata->backlight;
	123	}
	124
	125	if (!pdata) {
	126	dev_err(&pdev->dev, "platform data isn't assigned to "
	127	"backlight\n");
	128	return -EINVAL;
	129	}
	130
	131	data = kzalloc(sizeof(struct max8925_backlight_data), GFP_KERNEL);
	132	if (data == NULL)
	133	return -ENOMEM;
	134	strncpy(name, res->name, MAX8925_NAME_SIZE);
	135	data->chip = chip;
	136	data->current_brightness = 0;
	137
a19a6ee6 MG	138	memset(&props, 0, sizeof(struct backlight_properties));
a19a6ee6 MG	139	props.max_brightness = MAX_BRIGHTNESS;
4f811ef0	140	bl = backlight_device_register(name, &pdev->dev, data,
a19a6ee6	141	&max8925_backlight_ops, &props);
4f811ef0 HZ	142	if (IS_ERR(bl)) {
	143	dev_err(&pdev->dev, "failed to register backlight\n");
	144	kfree(data);
	145	return PTR_ERR(bl);
	146	}
4f811ef0 HZ	147	bl->props.brightness = MAX_BRIGHTNESS;
	148
	149	platform_set_drvdata(pdev, bl);
	150
	151	value = 0;
	152	if (pdata->lxw_scl)
	153	value \|= (1 << 7);
	154	if (pdata->lxw_freq)
	155	value \|= (LWX_FREQ(pdata->lxw_freq) << 4);
	156	if (pdata->dual_string)
	157	value \|= (1 << 1);
	158	ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 0xfe, value);
	159	if (ret < 0)
	160	goto out;
	161
	162	backlight_update_status(bl);
	163	return 0;
	164	out:
	165	kfree(data);
	166	return ret;
	167	}
	168
	169	static int __devexit max8925_backlight_remove(struct platform_device *pdev)
	170	{
	171	struct backlight_device *bl = platform_get_drvdata(pdev);
	172	struct max8925_backlight_data *data = bl_get_data(bl);
	173
	174	backlight_device_unregister(bl);
	175	kfree(data);
	176	return 0;
	177	}
	178
	179	static struct platform_driver max8925_backlight_driver = {
	180	.driver = {
	181	.name = "max8925-backlight",
	182	.owner = THIS_MODULE,
	183	},
	184	.probe = max8925_backlight_probe,
	185	.remove = __devexit_p(max8925_backlight_remove),
	186	};
	187
	188	static int __init max8925_backlight_init(void)
	189	{
	190	return platform_driver_register(&max8925_backlight_driver);
	191	}
	192	module_init(max8925_backlight_init);
	193
	194	static void __exit max8925_backlight_exit(void)
	195	{
	196	platform_driver_unregister(&max8925_backlight_driver);
	197	};
	198	module_exit(max8925_backlight_exit);
	199
	200	MODULE_DESCRIPTION("Backlight Driver for Maxim MAX8925");
	201	MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
	202	MODULE_LICENSE("GPL");
	203	MODULE_ALIAS("platform:max8925-backlight");