drivers/video/backlight/88pm860x_bl.c - linux - Git at Google

 /*
  * 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/of.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/fb.h>
 #include <linux/i2c.h>
 #include <linux/backlight.h>
 #include <linux/mfd/88pm860x.h>
 #include <linux/module.h>

 #define MAX_BRIGHTNESS		(0xFF)
 #define MIN_BRIGHTNESS		(0)

 #define CURRENT_BITMASK		(0x1F << 1)

 struct pm860x_backlight_data {
 	struct pm860x_chip *chip;
 	struct i2c_client *i2c;
 	int	current_brightness;
 	int	port;
 	int	pwm;
 	int	iset;
 	int	reg_duty_cycle;
 	int	reg_always_on;
 	int	reg_current;
 };

 static int backlight_power_set(struct pm860x_chip *chip, int port,
 		int on)
 {
 	int ret = -EINVAL;

 	switch (port) {
 	case 0:
 		ret = on ? pm8606_osc_enable(chip, WLED1_DUTY) :
 			pm8606_osc_disable(chip, WLED1_DUTY);
 		break;
 	case 1:
 		ret = on ? pm8606_osc_enable(chip, WLED2_DUTY) :
 			pm8606_osc_disable(chip, WLED2_DUTY);
 		break;
 	case 2:
 		ret = on ? pm8606_osc_enable(chip, WLED3_DUTY) :
 			pm8606_osc_disable(chip, WLED3_DUTY);
 		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;

 	if (brightness)
 		backlight_power_set(chip, data->port, 1);

 	ret = pm860x_reg_write(data->i2c, data->reg_duty_cycle, value);
 	if (ret < 0)
 		goto out;

 	if ((data->current_brightness == 0) && brightness) {
 		if (data->iset) {
 			ret = pm860x_set_bits(data->i2c, data->reg_current,
 					      CURRENT_BITMASK, 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, data->reg_always_on,
 					      PM8606_WLED_ON, PM8606_WLED_ON);
 		}
 	} else {
 		if (brightness == MAX_BRIGHTNESS) {
 			/* set WLED_ON bit as 100% */
 			ret = pm860x_set_bits(data->i2c, data->reg_always_on,
 					      PM8606_WLED_ON, PM8606_WLED_ON);
 		} else {
 			/* clear WLED_ON bit since it's not 100% */
 			ret = pm860x_set_bits(data->i2c, data->reg_always_on,
 					      PM8606_WLED_ON, 0);
 		}
 	}
 	if (ret < 0)
 		goto out;

 	if (brightness == 0)
 		backlight_power_set(chip, data->port, 0);

 	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, data->reg_duty_cycle);
 	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 const struct backlight_ops pm860x_backlight_ops = {
 	.options	= BL_CORE_SUSPENDRESUME,
 	.update_status	= pm860x_backlight_update_status,
 	.get_brightness	= pm860x_backlight_get_brightness,
 };

 #ifdef CONFIG_OF
 static int pm860x_backlight_dt_init(struct platform_device *pdev,
 				    struct pm860x_backlight_data *data,
 				    char *name)
 {
 	struct device_node *nproot, *np;
 	int iset = 0;

 	nproot = of_get_child_by_name(pdev->dev.parent->of_node, "backlights");
 	if (!nproot) {
 		dev_err(&pdev->dev, "failed to find backlights node\n");
 		return -ENODEV;
 	}
 	for_each_child_of_node(nproot, np) {
 		if (of_node_name_eq(np, name)) {
 			of_property_read_u32(np, "marvell,88pm860x-iset",
 					     &iset);
 			data->iset = PM8606_WLED_CURRENT(iset);
 			of_property_read_u32(np, "marvell,88pm860x-pwm",
 					     &data->pwm);
 			of_node_put(np);
 			break;
 		}
 	}
 	of_node_put(nproot);
 	return 0;
 }
 #else
 #define pm860x_backlight_dt_init(x, y, z)	(-1)
 #endif

 static int pm860x_backlight_probe(struct platform_device *pdev)
 {
 	struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
 	struct pm860x_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
 	struct pm860x_backlight_data *data;
 	struct backlight_device *bl;
 	struct resource *res;
 	struct backlight_properties props;
 	char name[MFD_NAME_SIZE];
 	int ret = 0;

 	data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data),
 			    GFP_KERNEL);
 	if (data == NULL)
 		return -ENOMEM;
 	res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle");
 	if (!res) {
 		dev_err(&pdev->dev, "No REG resource for duty cycle\n");
 		return -ENXIO;
 	}
 	data->reg_duty_cycle = res->start;
 	res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on");
 	if (!res) {
 		dev_err(&pdev->dev, "No REG resource for always on\n");
 		return -ENXIO;
 	}
 	data->reg_always_on = res->start;
 	res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current");
 	if (!res) {
 		dev_err(&pdev->dev, "No REG resource for current\n");
 		return -ENXIO;
 	}
 	data->reg_current = res->start;

 	memset(name, 0, MFD_NAME_SIZE);
 	sprintf(name, "backlight-%d", pdev->id);
 	data->port = pdev->id;
 	data->chip = chip;
 	data->i2c = (chip->id == CHIP_PM8606) ? chip->client : chip->companion;
 	data->current_brightness = MAX_BRIGHTNESS;
 	if (pm860x_backlight_dt_init(pdev, data, name)) {
 		if (pdata) {
 			data->pwm = pdata->pwm;
 			data->iset = pdata->iset;
 		}
 	}

 	memset(&props, 0, sizeof(struct backlight_properties));
 	props.type = BACKLIGHT_RAW;
 	props.max_brightness = MAX_BRIGHTNESS;
 	bl = devm_backlight_device_register(&pdev->dev, name, &pdev->dev, data,
 					&pm860x_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);

 	/* read current backlight */
 	ret = pm860x_backlight_get_brightness(bl);
 	if (ret < 0)
 		return ret;

 	backlight_update_status(bl);
 	return 0;
 }

 static struct platform_driver pm860x_backlight_driver = {
 	.driver		= {
 		.name	= "88pm860x-backlight",
 	},
 	.probe		= pm860x_backlight_probe,
 };

 module_platform_driver(pm860x_backlight_driver);

 MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:88pm860x-backlight");
	/*
	* 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/of.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/fb.h>
	#include <linux/i2c.h>
	#include <linux/backlight.h>
	#include <linux/mfd/88pm860x.h>
	#include <linux/module.h>

	#define MAX_BRIGHTNESS (0xFF)
	#define MIN_BRIGHTNESS (0)

	#define CURRENT_BITMASK (0x1F << 1)

	struct pm860x_backlight_data {
	struct pm860x_chip *chip;
	struct i2c_client *i2c;
	int current_brightness;
	int port;
	int pwm;
	int iset;
	int reg_duty_cycle;
	int reg_always_on;
	int reg_current;
	};

	static int backlight_power_set(struct pm860x_chip *chip, int port,
	int on)
	{
	int ret = -EINVAL;

	switch (port) {
	case 0:
	ret = on ? pm8606_osc_enable(chip, WLED1_DUTY) :
	pm8606_osc_disable(chip, WLED1_DUTY);
	break;
	case 1:
	ret = on ? pm8606_osc_enable(chip, WLED2_DUTY) :
	pm8606_osc_disable(chip, WLED2_DUTY);
	break;
	case 2:
	ret = on ? pm8606_osc_enable(chip, WLED3_DUTY) :
	pm8606_osc_disable(chip, WLED3_DUTY);
	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;

	if (brightness)
	backlight_power_set(chip, data->port, 1);

	ret = pm860x_reg_write(data->i2c, data->reg_duty_cycle, value);
	if (ret < 0)
	goto out;

	if ((data->current_brightness == 0) && brightness) {
	if (data->iset) {
	ret = pm860x_set_bits(data->i2c, data->reg_current,
	CURRENT_BITMASK, 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, data->reg_always_on,
	PM8606_WLED_ON, PM8606_WLED_ON);
	}
	} else {
	if (brightness == MAX_BRIGHTNESS) {
	/* set WLED_ON bit as 100% */
	ret = pm860x_set_bits(data->i2c, data->reg_always_on,
	PM8606_WLED_ON, PM8606_WLED_ON);
	} else {
	/* clear WLED_ON bit since it's not 100% */
	ret = pm860x_set_bits(data->i2c, data->reg_always_on,
	PM8606_WLED_ON, 0);
	}
	}
	if (ret < 0)
	goto out;

	if (brightness == 0)
	backlight_power_set(chip, data->port, 0);

	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, data->reg_duty_cycle);
	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 const struct backlight_ops pm860x_backlight_ops = {
	.options = BL_CORE_SUSPENDRESUME,
	.update_status = pm860x_backlight_update_status,
	.get_brightness = pm860x_backlight_get_brightness,
	};

	#ifdef CONFIG_OF
	static int pm860x_backlight_dt_init(struct platform_device *pdev,
	struct pm860x_backlight_data *data,
	char *name)
	{
	struct device_node nproot, np;
	int iset = 0;

	nproot = of_get_child_by_name(pdev->dev.parent->of_node, "backlights");
	if (!nproot) {
	dev_err(&pdev->dev, "failed to find backlights node\n");
	return -ENODEV;
	}
	for_each_child_of_node(nproot, np) {
	if (of_node_name_eq(np, name)) {
	of_property_read_u32(np, "marvell,88pm860x-iset",
	&iset);
	data->iset = PM8606_WLED_CURRENT(iset);
	of_property_read_u32(np, "marvell,88pm860x-pwm",
	&data->pwm);
	of_node_put(np);
	break;
	}
	}
	of_node_put(nproot);
	return 0;
	}
	#else
	#define pm860x_backlight_dt_init(x, y, z) (-1)
	#endif

	static int pm860x_backlight_probe(struct platform_device *pdev)
	{
	struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
	struct pm860x_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
	struct pm860x_backlight_data *data;
	struct backlight_device *bl;
	struct resource *res;
	struct backlight_properties props;
	char name[MFD_NAME_SIZE];
	int ret = 0;

	data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data),
	GFP_KERNEL);
	if (data == NULL)
	return -ENOMEM;
	res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle");
	if (!res) {
	dev_err(&pdev->dev, "No REG resource for duty cycle\n");
	return -ENXIO;
	}
	data->reg_duty_cycle = res->start;
	res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on");
	if (!res) {
	dev_err(&pdev->dev, "No REG resource for always on\n");
	return -ENXIO;
	}
	data->reg_always_on = res->start;
	res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current");
	if (!res) {
	dev_err(&pdev->dev, "No REG resource for current\n");
	return -ENXIO;
	}
	data->reg_current = res->start;

	memset(name, 0, MFD_NAME_SIZE);
	sprintf(name, "backlight-%d", pdev->id);
	data->port = pdev->id;
	data->chip = chip;
	data->i2c = (chip->id == CHIP_PM8606) ? chip->client : chip->companion;
	data->current_brightness = MAX_BRIGHTNESS;
	if (pm860x_backlight_dt_init(pdev, data, name)) {
	if (pdata) {
	data->pwm = pdata->pwm;
	data->iset = pdata->iset;
	}
	}

	memset(&props, 0, sizeof(struct backlight_properties));
	props.type = BACKLIGHT_RAW;
	props.max_brightness = MAX_BRIGHTNESS;
	bl = devm_backlight_device_register(&pdev->dev, name, &pdev->dev, data,
	&pm860x_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);

	/* read current backlight */
	ret = pm860x_backlight_get_brightness(bl);
	if (ret < 0)
	return ret;

	backlight_update_status(bl);
	return 0;
	}

	static struct platform_driver pm860x_backlight_driver = {
	.driver = {
	.name = "88pm860x-backlight",
	},
	.probe = pm860x_backlight_probe,
	};

	module_platform_driver(pm860x_backlight_driver);

	MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
	MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:88pm860x-backlight");