Commit 4f811ef0 authored by Haojian Zhuang's avatar Haojian Zhuang Committed by Samuel Ortiz
Browse files

backlight: Enable max8925 backlight 



Enable max8925 backlight sub device.

Signed-off-by: default avatarHaojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent 1ad99893

drivers/video/backlight/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -212,6 +212,13 @@ config BACKLIGHT_DA903X 
	  If you have a LCD backlight connected to the WLED output of DA9030

	  or DA9034 WLED output, say Y here to enable this driver.



config BACKLIGHT_MAX8925

	tristate "Backlight driver for MAX8925"

	depends on BACKLIGHT_CLASS_DEVICE && MFD_MAX8925

	help

	  If you have a LCD backlight connected to the WLED output of MAX8925

	  WLED output, say Y here to enable this driver.



config BACKLIGHT_MBP_NVIDIA

       tristate "MacBook Pro Nvidia Backlight Driver"

       depends on BACKLIGHT_CLASS_DEVICE && X86

drivers/video/backlight/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ obj-$(CONFIG_BACKLIGHT_PROGEAR) += progear_bl.o 
obj-$(CONFIG_BACKLIGHT_CARILLO_RANCH) += cr_bllcd.o

obj-$(CONFIG_BACKLIGHT_PWM)	+= pwm_bl.o

obj-$(CONFIG_BACKLIGHT_DA903X)	+= da903x_bl.o

obj-$(CONFIG_BACKLIGHT_MAX8925)	+= max8925_bl.o

obj-$(CONFIG_BACKLIGHT_MBP_NVIDIA) += mbp_nvidia_bl.o

obj-$(CONFIG_BACKLIGHT_TOSA)	+= tosa_bl.o

obj-$(CONFIG_BACKLIGHT_SAHARA)	+= kb3886_bl.o

drivers/video/backlight/max8925_bl.c

0 → 100644
+200 −0
Original line number Diff line number Diff line 
/*

 * 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>



#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 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;



	bl = backlight_device_register(name, &pdev->dev, data,

					&max8925_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);



	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");