Commit d07e8bf8 authored by Haojian Zhuang's avatar Haojian Zhuang Committed by Samuel Ortiz
Browse files

backlight: Enable backlight in 88pm860x 



At most, three backlight device can be supported in 88pm860x driver.

Signed-off-by: default avatarHaojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent a16122bc

drivers/video/backlight/88pm860x_bl.c

0 → 100644
+304 −0
Original line number Diff line number Diff line 
/*

 * Backlight driver for Marvell Semiconductor 88PM8606

 *

 * 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/88pm860x.h>



#define MAX_BRIGHTNESS		(0xFF)

#define MIN_BRIGHTNESS		(0)



#define CURRENT_MASK		(0x1F << 1)



struct pm860x_backlight_data {

	struct pm860x_chip *chip;

	struct i2c_client *i2c;

	int	current_brightness;

	int	port;

	int	pwm;

	int	iset;

};



static inline int wled_a(int port)

{

	int ret;



	ret = ((port - PM8606_BACKLIGHT1) << 1) + 2;

	return ret;

}



static inline int wled_b(int port)

{

	int ret;



	ret = ((port - PM8606_BACKLIGHT1) << 1) + 3;

	return ret;

}



/* WLED2 & WLED3 share the same IDC */

static inline int wled_idc(int port)

{

	int ret;



	switch (port) {

	case PM8606_BACKLIGHT1:

	case PM8606_BACKLIGHT2:

		ret = ((port - PM8606_BACKLIGHT1) << 1) + 3;

		break;

	case PM8606_BACKLIGHT3:

	default:

		ret = ((port - PM8606_BACKLIGHT2) << 1) + 3;

		break;

	}

	return ret;

}



static int pm860x_backlight_set(struct backlight_device *bl, int brightness)

{

	struct pm860x_backlight_data *data = bl_get_data(bl);

	struct pm860x_chip *chip = data->chip;

	unsigned char value;

	int ret;



	if (brightness > MAX_BRIGHTNESS)

		value = MAX_BRIGHTNESS;

	else

		value = brightness;



	ret = pm860x_reg_write(data->i2c, wled_a(data->port), value);

	if (ret < 0)

		goto out;



	if ((data->current_brightness == 0) && brightness) {

		if (data->iset) {

			ret = pm860x_set_bits(data->i2c, wled_idc(data->port),

					      CURRENT_MASK, data->iset);

			if (ret < 0)

				goto out;

		}

		if (data->pwm) {

			ret = pm860x_set_bits(data->i2c, PM8606_PWM,

					      PM8606_PWM_FREQ_MASK, data->pwm);

			if (ret < 0)

				goto out;

		}

		if (brightness == MAX_BRIGHTNESS) {

			/* set WLED_ON bit as 100% */

			ret = pm860x_set_bits(data->i2c, wled_b(data->port),

					      PM8606_WLED_ON, PM8606_WLED_ON);

		}

	} else {

		if (brightness == MAX_BRIGHTNESS) {

			/* set WLED_ON bit as 100% */

			ret = pm860x_set_bits(data->i2c, wled_b(data->port),

					      PM8606_WLED_ON, PM8606_WLED_ON);

		} else {

			/* clear WLED_ON bit since it's not 100% */

			ret = pm860x_set_bits(data->i2c, wled_b(data->port),

					      PM8606_WLED_ON, 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 pm860x_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 pm860x_backlight_set(bl, brightness);

}



static int pm860x_backlight_get_brightness(struct backlight_device *bl)

{

	struct pm860x_backlight_data *data = bl_get_data(bl);

	struct pm860x_chip *chip = data->chip;

	int ret;



	ret = pm860x_reg_read(data->i2c, wled_a(data->port));

	if (ret < 0)

		goto out;

	data->current_brightness = ret;

	dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);

	return data->current_brightness;

out:

	return -EINVAL;

}



static struct backlight_ops pm860x_backlight_ops = {

	.options	= BL_CORE_SUSPENDRESUME,

	.update_status	= pm860x_backlight_update_status,

	.get_brightness	= pm860x_backlight_get_brightness,

};



static int __check_device(struct pm860x_backlight_pdata *pdata, char *name)

{

	struct pm860x_backlight_pdata *p = pdata;

	int ret = -EINVAL;



	while (p && p->id) {

		if ((p->id != PM8606_ID_BACKLIGHT) || (p->flags < 0))

			break;



		if (!strncmp(name, pm860x_backlight_name[p->flags],

			MFD_NAME_SIZE)) {

			ret = (int)p->flags;

			break;

		}

		p++;

	}

	return ret;

}



static int pm860x_backlight_probe(struct platform_device *pdev)

{

	struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);

	struct pm860x_platform_data *pm860x_pdata;

	struct pm860x_backlight_pdata *pdata = NULL;

	struct pm860x_backlight_data *data;

	struct backlight_device *bl;

	struct resource *res;

	unsigned char value;

	char name[MFD_NAME_SIZE];

	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) {

		pm860x_pdata = pdev->dev.parent->platform_data;

		pdata = pm860x_pdata->backlight;

	}

	if (pdata == NULL) {

		dev_err(&pdev->dev, "platform data isn't assigned to "

			"backlight\n");

		return -EINVAL;

	}



	data = kzalloc(sizeof(struct pm860x_backlight_data), GFP_KERNEL);

	if (data == NULL)

		return -ENOMEM;

	strncpy(name, res->name, MFD_NAME_SIZE);

	data->chip = chip;

	data->i2c = (chip->id == CHIP_PM8606) ? chip->client	\

			: chip->companion;

	data->current_brightness = MAX_BRIGHTNESS;

	data->pwm = pdata->pwm;

	data->iset = pdata->iset;

	data->port = __check_device(pdata, name);

	if (data->port < 0) {

		dev_err(&pdev->dev, "wrong platform data is assigned");

		return -EINVAL;

	}



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

					&pm860x_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);



	/* Enable reference VSYS */

	ret = pm860x_reg_read(data->i2c, PM8606_VSYS);

	if (ret < 0)

		goto out;

	if ((ret & PM8606_VSYS_EN) == 0) {

		value = ret | PM8606_VSYS_EN;

		ret = pm860x_reg_write(data->i2c, PM8606_VSYS, value);

		if (ret < 0)

			goto out;

	}

	/* Enable reference OSC */

	ret = pm860x_reg_read(data->i2c, PM8606_MISC);

	if (ret < 0)

		goto out;

	if ((ret & PM8606_MISC_OSC_EN) == 0) {

		value = ret | PM8606_MISC_OSC_EN;

		ret = pm860x_reg_write(data->i2c, PM8606_MISC, value);

		if (ret < 0)

			goto out;

	}

	/* read current backlight */

	ret = pm860x_backlight_get_brightness(bl);

	if (ret < 0)

		goto out;



	backlight_update_status(bl);

	return 0;

out:

	kfree(data);

	return ret;

}



static int pm860x_backlight_remove(struct platform_device *pdev)

{

	struct backlight_device *bl = platform_get_drvdata(pdev);

	struct pm860x_backlight_data *data = bl_get_data(bl);



	backlight_device_unregister(bl);

	kfree(data);

	return 0;

}



static struct platform_driver pm860x_backlight_driver = {

	.driver		= {

		.name	= "88pm860x-backlight",

		.owner	= THIS_MODULE,

	},

	.probe		= pm860x_backlight_probe,

	.remove		= pm860x_backlight_remove,

};



static int __init pm860x_backlight_init(void)

{

	return platform_driver_register(&pm860x_backlight_driver);

}

module_init(pm860x_backlight_init);



static void __exit pm860x_backlight_exit(void)

{

	platform_driver_unregister(&pm860x_backlight_driver);

}

module_exit(pm860x_backlight_exit);



MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");

MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");

MODULE_LICENSE("GPL");

MODULE_ALIAS("platform:88pm860x-backlight");

drivers/video/backlight/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -262,3 +262,9 @@ config BACKLIGHT_ADP5520 
	  To compile this driver as a module, choose M here: the module will

	  be called adp5520_bl.



config BACKLIGHT_88PM860X

	tristate "Backlight Driver for 88PM8606 using WLED"

	depends on BACKLIGHT_CLASS_DEVICE && MFD_88PM860X

	help

	  Say Y to enable the backlight driver for Marvell 88PM8606.

drivers/video/backlight/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -28,4 +28,5 @@ obj-$(CONFIG_BACKLIGHT_SAHARA) += kb3886_bl.o 
obj-$(CONFIG_BACKLIGHT_WM831X)	+= wm831x_bl.o

obj-$(CONFIG_BACKLIGHT_ADX)    += adx_bl.o

obj-$(CONFIG_BACKLIGHT_ADP5520)	+= adp5520_bl.o

obj-$(CONFIG_BACKLIGHT_88PM860X) += 88pm860x_bl.o