[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;
};

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 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_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 = devm_kzalloc(&pdev->dev, 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.type = BACKLIGHT_RAW;
	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");
		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:
	backlight_device_unregister(bl);
	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
	30	int current_brightness;
	31	};
	32
	33	static int max8925_backlight_set(struct backlight_device *bl, int brightness)
	34	{
	35	struct max8925_backlight_data *data = bl_get_data(bl);
	36	struct max8925_chip *chip = data->chip;
	37	unsigned char value;
	38	int ret;
	39
	40	if (brightness > MAX_BRIGHTNESS)
	41	value = MAX_BRIGHTNESS;
	42	else
	43	value = brightness;
	44
	45	ret = max8925_reg_write(chip->i2c, MAX8925_WLED_CNTL, value);
	46	if (ret < 0)
	47	goto out;
	48
	49	if (!data->current_brightness && brightness)
	50	/* enable WLED output */
	51	ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 1, 1);
	52	else if (!brightness)
	53	/* disable WLED output */
	54	ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 1, 0);
	55	if (ret < 0)
	56	goto out;
	57	dev_dbg(chip->dev, "set brightness %d\n", value);
	58	data->current_brightness = value;
	59	return 0;
	60	out:
	61	dev_dbg(chip->dev, "set brightness %d failure with return value:%d\n",
	62	value, ret);
	63	return ret;
	64	}
	65
	66	static int max8925_backlight_update_status(struct backlight_device *bl)
	67	{
	68	int brightness = bl->props.brightness;
	69
	70	if (bl->props.power != FB_BLANK_UNBLANK)
	71	brightness = 0;
	72
	73	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
	74	brightness = 0;
	75
	76	if (bl->props.state & BL_CORE_SUSPENDED)
	77	brightness = 0;
	78
	79	return max8925_backlight_set(bl, brightness);
	80	}
	81
	82	static int max8925_backlight_get_brightness(struct backlight_device *bl)
	83	{
	84	struct max8925_backlight_data *data = bl_get_data(bl);
85	struct max8925_chip *chip = data->chip;
86	int ret;
87
88	ret = max8925_reg_read(chip->i2c, MAX8925_WLED_CNTL);
89	if (ret < 0)
90	return -EINVAL;
91	data->current_brightness = ret;
92	dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
93	return ret;
94	}
95
acc2472e	96	static const struct backlight_ops max8925_backlight_ops = {
4f811ef0 HZ	97	.options = BL_CORE_SUSPENDRESUME,
	98	.update_status = max8925_backlight_update_status,
	99	.get_brightness = max8925_backlight_get_brightness,
	100	};
	101
	102	static int __devinit max8925_backlight_probe(struct platform_device *pdev)
	103	{
	104	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
	105	struct max8925_platform_data *max8925_pdata;
	106	struct max8925_backlight_pdata *pdata = NULL;
	107	struct max8925_backlight_data *data;
	108	struct backlight_device *bl;
a19a6ee6	109	struct backlight_properties props;
4f811ef0 HZ	110	struct resource *res;
	111	char name[MAX8925_NAME_SIZE];
	112	unsigned char value;
	113	int ret;
	114
	115	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	116	if (res == NULL) {
	117	dev_err(&pdev->dev, "No I/O resource!\n");
	118	return -EINVAL;
	119	}
	120
	121	if (pdev->dev.parent->platform_data) {
	122	max8925_pdata = pdev->dev.parent->platform_data;
	123	pdata = max8925_pdata->backlight;
	124	}
	125
	126	if (!pdata) {
	127	dev_err(&pdev->dev, "platform data isn't assigned to "
	128	"backlight\n");
	129	return -EINVAL;
	130	}
	131
ce969228 JL	132	data = devm_kzalloc(&pdev->dev, sizeof(struct max8925_backlight_data),
ce969228 JL	133	GFP_KERNEL);
4f811ef0 HZ	134	if (data == NULL)
	135	return -ENOMEM;
	136	strncpy(name, res->name, MAX8925_NAME_SIZE);
	137	data->chip = chip;
	138	data->current_brightness = 0;
	139
a19a6ee6	140	memset(&props, 0, sizeof(struct backlight_properties));
bb7ca747	141	props.type = BACKLIGHT_RAW;
a19a6ee6	142	props.max_brightness = MAX_BRIGHTNESS;
4f811ef0	143	bl = backlight_device_register(name, &pdev->dev, data,
a19a6ee6	144	&max8925_backlight_ops, &props);
4f811ef0 HZ	145	if (IS_ERR(bl)) {
4f811ef0 HZ	146	dev_err(&pdev->dev, "failed to register backlight\n");
4f811ef0 HZ	147	return PTR_ERR(bl);
4f811ef0 HZ	148	}
4f811ef0 HZ	149	bl->props.brightness = MAX_BRIGHTNESS;
	150
	151	platform_set_drvdata(pdev, bl);
	152
	153	value = 0;
	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	ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 0xfe, value);
	161	if (ret < 0)
	162	goto out;
	163
	164	backlight_update_status(bl);
	165	return 0;
	166	out:
146e10a8	167	backlight_device_unregister(bl);
4f811ef0 HZ	168	return ret;
	169	}
	170
	171	static int __devexit max8925_backlight_remove(struct platform_device *pdev)
	172	{
	173	struct backlight_device *bl = platform_get_drvdata(pdev);
4f811ef0 HZ	174
4f811ef0 HZ	175	backlight_device_unregister(bl);
4f811ef0 HZ	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
81178e02	188	module_platform_driver(max8925_backlight_driver);
4f811ef0 HZ	189
	190	MODULE_DESCRIPTION("Backlight Driver for Maxim MAX8925");
	191	MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
	192	MODULE_LICENSE("GPL");
	193	MODULE_ALIAS("platform:max8925-backlight");