276 lines
		
	
	
		
			7.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			276 lines
		
	
	
		
			7.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * 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_cmp(np->name, 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");
 | 
