276 lines
		
	
	
		
			7.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			276 lines
		
	
	
		
			7.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Backlight driver for Marvell Semiconductor 88PM8606
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 *
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 * Copyright (C) 2009 Marvell International Ltd.
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 *	Haojian Zhuang <haojian.zhuang@marvell.com>
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License version 2 as
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 * published by the Free Software Foundation.
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 */
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/fb.h>
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#include <linux/i2c.h>
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#include <linux/backlight.h>
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#include <linux/mfd/88pm860x.h>
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#include <linux/module.h>
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#define MAX_BRIGHTNESS		(0xFF)
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#define MIN_BRIGHTNESS		(0)
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#define CURRENT_BITMASK		(0x1F << 1)
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struct pm860x_backlight_data {
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	struct pm860x_chip *chip;
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	struct i2c_client *i2c;
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	int	current_brightness;
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	int	port;
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	int	pwm;
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	int	iset;
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	int	reg_duty_cycle;
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	int	reg_always_on;
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	int	reg_current;
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};
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static int backlight_power_set(struct pm860x_chip *chip, int port,
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		int on)
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{
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	int ret = -EINVAL;
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	switch (port) {
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	case 0:
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		ret = on ? pm8606_osc_enable(chip, WLED1_DUTY) :
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			pm8606_osc_disable(chip, WLED1_DUTY);
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		break;
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	case 1:
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		ret = on ? pm8606_osc_enable(chip, WLED2_DUTY) :
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			pm8606_osc_disable(chip, WLED2_DUTY);
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		break;
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	case 2:
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		ret = on ? pm8606_osc_enable(chip, WLED3_DUTY) :
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			pm8606_osc_disable(chip, WLED3_DUTY);
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		break;
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	}
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	return ret;
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}
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static int pm860x_backlight_set(struct backlight_device *bl, int brightness)
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{
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	struct pm860x_backlight_data *data = bl_get_data(bl);
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	struct pm860x_chip *chip = data->chip;
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	unsigned char value;
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	int ret;
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	if (brightness > MAX_BRIGHTNESS)
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		value = MAX_BRIGHTNESS;
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	else
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		value = brightness;
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	if (brightness)
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		backlight_power_set(chip, data->port, 1);
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	ret = pm860x_reg_write(data->i2c, data->reg_duty_cycle, value);
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	if (ret < 0)
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		goto out;
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	if ((data->current_brightness == 0) && brightness) {
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		if (data->iset) {
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			ret = pm860x_set_bits(data->i2c, data->reg_current,
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					      CURRENT_BITMASK, data->iset);
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			if (ret < 0)
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				goto out;
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		}
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		if (data->pwm) {
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			ret = pm860x_set_bits(data->i2c, PM8606_PWM,
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					      PM8606_PWM_FREQ_MASK, data->pwm);
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			if (ret < 0)
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				goto out;
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		}
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		if (brightness == MAX_BRIGHTNESS) {
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			/* set WLED_ON bit as 100% */
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			ret = pm860x_set_bits(data->i2c, data->reg_always_on,
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					      PM8606_WLED_ON, PM8606_WLED_ON);
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		}
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	} else {
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		if (brightness == MAX_BRIGHTNESS) {
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			/* set WLED_ON bit as 100% */
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			ret = pm860x_set_bits(data->i2c, data->reg_always_on,
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					      PM8606_WLED_ON, PM8606_WLED_ON);
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		} else {
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			/* clear WLED_ON bit since it's not 100% */
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			ret = pm860x_set_bits(data->i2c, data->reg_always_on,
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					      PM8606_WLED_ON, 0);
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		}
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	}
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	if (ret < 0)
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		goto out;
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	if (brightness == 0)
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		backlight_power_set(chip, data->port, 0);
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	dev_dbg(chip->dev, "set brightness %d\n", value);
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	data->current_brightness = value;
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	return 0;
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out:
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	dev_dbg(chip->dev, "set brightness %d failure with return value: %d\n",
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		value, ret);
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	return ret;
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}
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static int pm860x_backlight_update_status(struct backlight_device *bl)
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{
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	int brightness = bl->props.brightness;
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	if (bl->props.power != FB_BLANK_UNBLANK)
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		brightness = 0;
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	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
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		brightness = 0;
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	if (bl->props.state & BL_CORE_SUSPENDED)
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		brightness = 0;
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	return pm860x_backlight_set(bl, brightness);
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}
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static int pm860x_backlight_get_brightness(struct backlight_device *bl)
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{
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	struct pm860x_backlight_data *data = bl_get_data(bl);
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	struct pm860x_chip *chip = data->chip;
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	int ret;
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	ret = pm860x_reg_read(data->i2c, data->reg_duty_cycle);
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	if (ret < 0)
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		goto out;
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	data->current_brightness = ret;
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	dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
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	return data->current_brightness;
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out:
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	return -EINVAL;
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}
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static const struct backlight_ops pm860x_backlight_ops = {
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	.options	= BL_CORE_SUSPENDRESUME,
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	.update_status	= pm860x_backlight_update_status,
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	.get_brightness	= pm860x_backlight_get_brightness,
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};
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#ifdef CONFIG_OF
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static int pm860x_backlight_dt_init(struct platform_device *pdev,
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				    struct pm860x_backlight_data *data,
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				    char *name)
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{
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	struct device_node *nproot, *np;
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	int iset = 0;
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	nproot = of_get_child_by_name(pdev->dev.parent->of_node, "backlights");
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	if (!nproot) {
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		dev_err(&pdev->dev, "failed to find backlights node\n");
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		return -ENODEV;
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	}
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	for_each_child_of_node(nproot, np) {
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		if (!of_node_cmp(np->name, name)) {
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			of_property_read_u32(np, "marvell,88pm860x-iset",
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					     &iset);
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			data->iset = PM8606_WLED_CURRENT(iset);
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			of_property_read_u32(np, "marvell,88pm860x-pwm",
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					     &data->pwm);
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			of_node_put(np);
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			break;
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		}
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	}
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	of_node_put(nproot);
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	return 0;
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}
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#else
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#define pm860x_backlight_dt_init(x, y, z)	(-1)
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#endif
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static int pm860x_backlight_probe(struct platform_device *pdev)
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{
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	struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
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	struct pm860x_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
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	struct pm860x_backlight_data *data;
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	struct backlight_device *bl;
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	struct resource *res;
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	struct backlight_properties props;
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	char name[MFD_NAME_SIZE];
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	int ret = 0;
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	data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data),
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			    GFP_KERNEL);
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	if (data == NULL)
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		return -ENOMEM;
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	res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle");
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	if (!res) {
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		dev_err(&pdev->dev, "No REG resource for duty cycle\n");
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		return -ENXIO;
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	}
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	data->reg_duty_cycle = res->start;
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	res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on");
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	if (!res) {
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		dev_err(&pdev->dev, "No REG resource for always on\n");
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		return -ENXIO;
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	}
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	data->reg_always_on = res->start;
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	res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current");
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	if (!res) {
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		dev_err(&pdev->dev, "No REG resource for current\n");
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		return -ENXIO;
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	}
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	data->reg_current = res->start;
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	memset(name, 0, MFD_NAME_SIZE);
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	sprintf(name, "backlight-%d", pdev->id);
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	data->port = pdev->id;
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	data->chip = chip;
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	data->i2c = (chip->id == CHIP_PM8606) ? chip->client : chip->companion;
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	data->current_brightness = MAX_BRIGHTNESS;
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	if (pm860x_backlight_dt_init(pdev, data, name)) {
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		if (pdata) {
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			data->pwm = pdata->pwm;
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			data->iset = pdata->iset;
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		}
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	}
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	memset(&props, 0, sizeof(struct backlight_properties));
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	props.type = BACKLIGHT_RAW;
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	props.max_brightness = MAX_BRIGHTNESS;
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	bl = devm_backlight_device_register(&pdev->dev, name, &pdev->dev, data,
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					&pm860x_backlight_ops, &props);
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	if (IS_ERR(bl)) {
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		dev_err(&pdev->dev, "failed to register backlight\n");
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		return PTR_ERR(bl);
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	}
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	bl->props.brightness = MAX_BRIGHTNESS;
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	platform_set_drvdata(pdev, bl);
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	/* read current backlight */
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	ret = pm860x_backlight_get_brightness(bl);
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	if (ret < 0)
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		return ret;
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	backlight_update_status(bl);
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	return 0;
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}
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static struct platform_driver pm860x_backlight_driver = {
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	.driver		= {
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		.name	= "88pm860x-backlight",
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	},
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	.probe		= pm860x_backlight_probe,
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};
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module_platform_driver(pm860x_backlight_driver);
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MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
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MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:88pm860x-backlight");
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