text: /*
   * Backlight driver for Analog Devices ADP5520/ADP5501 MFD PMICs
   *
   * Copyright 2009 Analog Devices Inc.
   *
   * Licensed under the GPL-2 or later.
   */
  
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/platform_device.h>
  #include <linux/fb.h>
  #include <linux/backlight.h>
  #include <linux/mfd/adp5520.h>
  #include <linux/slab.h>
  #include <linux/module.h>
  
  struct adp5520_bl {
  	struct device *master;
  	struct adp5520_backlight_platform_data *pdata;
  	struct mutex lock;
  	unsigned long cached_daylight_max;
  	int id;
  	int current_brightness;
  };
  
  static int adp5520_bl_set(struct backlight_device *bl, int brightness)
  {
  	struct adp5520_bl *data = bl_get_data(bl);
  	struct device *master = data->master;
  	int ret = 0;
  
  	if (data->pdata->en_ambl_sens) {
  		if ((brightness > 0) && (brightness < ADP5020_MAX_BRIGHTNESS)) {
  			/* Disable Ambient Light auto adjust */
  			ret |= adp5520_clr_bits(master, ADP5520_BL_CONTROL,
  					ADP5520_BL_AUTO_ADJ);
  			ret |= adp5520_write(master, ADP5520_DAYLIGHT_MAX,
  					brightness);
  		} else {
  			/*
  			 * MAX_BRIGHTNESS -> Enable Ambient Light auto adjust
  			 * restore daylight l3 sysfs brightness
  			 */
  			ret |= adp5520_write(master, ADP5520_DAYLIGHT_MAX,
  					 data->cached_daylight_max);
  			ret |= adp5520_set_bits(master, ADP5520_BL_CONTROL,
  					 ADP5520_BL_AUTO_ADJ);
  		}
  	} else {
  		ret |= adp5520_write(master, ADP5520_DAYLIGHT_MAX, brightness);
  	}
  
  	if (data->current_brightness && brightness == 0)
  		ret |= adp5520_set_bits(master,
  				ADP5520_MODE_STATUS, ADP5520_DIM_EN);
  	else if (data->current_brightness == 0 && brightness)
  		ret |= adp5520_clr_bits(master,
  				ADP5520_MODE_STATUS, ADP5520_DIM_EN);
  
  	if (!ret)
  		data->current_brightness = brightness;
  
  	return ret;
  }
  
  static int adp5520_bl_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;
  
  	return adp5520_bl_set(bl, brightness);
  }
  
  static int adp5520_bl_get_brightness(struct backlight_device *bl)
  {
  	struct adp5520_bl *data = bl_get_data(bl);
  	int error;
  	uint8_t reg_val;
  
  	error = adp5520_read(data->master, ADP5520_BL_VALUE, &reg_val);
  
  	return error ? data->current_brightness : reg_val;
  }
  
  static const struct backlight_ops adp5520_bl_ops = {
  	.update_status	= adp5520_bl_update_status,
  	.get_brightness	= adp5520_bl_get_brightness,
  };
  
  static int adp5520_bl_setup(struct backlight_device *bl)
  {
  	struct adp5520_bl *data = bl_get_data(bl);
  	struct device *master = data->master;
  	struct adp5520_backlight_platform_data *pdata = data->pdata;
  	int ret = 0;
  
  	ret |= adp5520_write(master, ADP5520_DAYLIGHT_MAX,
  				pdata->l1_daylight_max);
  	ret |= adp5520_write(master, ADP5520_DAYLIGHT_DIM,
  				pdata->l1_daylight_dim);
  
  	if (pdata->en_ambl_sens) {
  		data->cached_daylight_max = pdata->l1_daylight_max;
  		ret |= adp5520_write(master, ADP5520_OFFICE_MAX,
  				pdata->l2_office_max);
  		ret |= adp5520_write(master, ADP5520_OFFICE_DIM,
  				pdata->l2_office_dim);
  		ret |= adp5520_write(master, ADP5520_DARK_MAX,
  				pdata->l3_dark_max);
  		ret |= adp5520_write(master, ADP5520_DARK_DIM,
  				pdata->l3_dark_dim);
  		ret |= adp5520_write(master, ADP5520_L2_TRIP,
  				pdata->l2_trip);
  		ret |= adp5520_write(master, ADP5520_L2_HYS,
  				pdata->l2_hyst);
  		ret |= adp5520_write(master, ADP5520_L3_TRIP,
  				 pdata->l3_trip);
  		ret |= adp5520_write(master, ADP5520_L3_HYS,
  				pdata->l3_hyst);
  		ret |= adp5520_write(master, ADP5520_ALS_CMPR_CFG,
  				ALS_CMPR_CFG_VAL(pdata->abml_filt,
  				ADP5520_L3_EN));
  	}
  
  	ret |= adp5520_write(master, ADP5520_BL_CONTROL,
  			BL_CTRL_VAL(pdata->fade_led_law,
  					pdata->en_ambl_sens));
  
  	ret |= adp5520_write(master, ADP5520_BL_FADE, FADE_VAL(pdata->fade_in,
  			pdata->fade_out));
  
  	ret |= adp5520_set_bits(master, ADP5520_MODE_STATUS,
  			ADP5520_BL_EN | ADP5520_DIM_EN);
  
  	return ret;
  }
  
  static ssize_t adp5520_show(struct device *dev, char *buf, int reg)
  {
  	struct adp5520_bl *data = dev_get_drvdata(dev);
  	int ret;
  	uint8_t reg_val;
  
  	mutex_lock(&data->lock);
  	ret = adp5520_read(data->master, reg, &reg_val);
  	mutex_unlock(&data->lock);
  
  	if (ret < 0)
  		return ret;
  
  	return sprintf(buf, "%u\n", reg_val);
  }
  
  static ssize_t adp5520_store(struct device *dev, const char *buf,
  			 size_t count, int reg)
  {
  	struct adp5520_bl *data = dev_get_drvdata(dev);
  	unsigned long val;
  	int ret;
  
  	ret = kstrtoul(buf, 10, &val);
  	if (ret)
  		return ret;
  
  	mutex_lock(&data->lock);
  	adp5520_write(data->master, reg, val);
  	mutex_unlock(&data->lock);
  
  	return count;
  }
  
  static ssize_t adp5520_bl_dark_max_show(struct device *dev,
  			struct device_attribute *attr, char *buf)
  {
  	return adp5520_show(dev, buf, ADP5520_DARK_MAX);
  }
  
  static ssize_t adp5520_bl_dark_max_store(struct device *dev,
  			struct device_attribute *attr,
  			const char *buf, size_t count)
  {
  	return adp5520_store(dev, buf, count, ADP5520_DARK_MAX);
  }
  static DEVICE_ATTR(dark_max, 0664, adp5520_bl_dark_max_show,
  			adp5520_bl_dark_max_store);
  
  static ssize_t adp5520_bl_office_max_show(struct device *dev,
  			struct device_attribute *attr, char *buf)
  {
  	return adp5520_show(dev, buf, ADP5520_OFFICE_MAX);
  }
  
  static ssize_t adp5520_bl_office_max_store(struct device *dev,
  			struct device_attribute *attr,
  			const char *buf, size_t count)
  {
  	return adp5520_store(dev, buf, count, ADP5520_OFFICE_MAX);
  }
  static DEVICE_ATTR(office_max, 0664, adp5520_bl_office_max_show,
  			adp5520_bl_office_max_store);
  
  static ssize_t adp5520_bl_daylight_max_show(struct device *dev,
  			struct device_attribute *attr, char *buf)
  {
  	return adp5520_show(dev, buf, ADP5520_DAYLIGHT_MAX);
  }
  
  static ssize_t adp5520_bl_daylight_max_store(struct device *dev,
  			struct device_attribute *attr,
  			const char *buf, size_t count)
  {
  	struct adp5520_bl *data = dev_get_drvdata(dev);
  	int ret;
  
  	ret = kstrtoul(buf, 10, &data->cached_daylight_max);
  	if (ret < 0)
  		return ret;
  
  	return adp5520_store(dev, buf, count, ADP5520_DAYLIGHT_MAX);
  }
  static DEVICE_ATTR(daylight_max, 0664, adp5520_bl_daylight_max_show,
  			adp5520_bl_daylight_max_store);
  
  static ssize_t adp5520_bl_dark_dim_show(struct device *dev,
  			struct device_attribute *attr, char *buf)
  {
  	return adp5520_show(dev, buf, ADP5520_DARK_DIM);
  }
  
  static ssize_t adp5520_bl_dark_dim_store(struct device *dev,
  			struct device_attribute *attr,
  			const char *buf, size_t count)
  {
  	return adp5520_store(dev, buf, count, ADP5520_DARK_DIM);
  }
  static DEVICE_ATTR(dark_dim, 0664, adp5520_bl_dark_dim_show,
  			adp5520_bl_dark_dim_store);
  
  static ssize_t adp5520_bl_office_dim_show(struct device *dev,
  			struct device_attribute *attr, char *buf)
  {
  	return adp5520_show(dev, buf, ADP5520_OFFICE_DIM);
  }
  
  static ssize_t adp5520_bl_office_dim_store(struct device *dev,
  			struct device_attribute *attr,
  			const char *buf, size_t count)
  {
  	return adp5520_store(dev, buf, count, ADP5520_OFFICE_DIM);
  }
  static DEVICE_ATTR(office_dim, 0664, adp5520_bl_office_dim_show,
  			adp5520_bl_office_dim_store);
  
  static ssize_t adp5520_bl_daylight_dim_show(struct device *dev,
  			struct device_attribute *attr, char *buf)
  {
  	return adp5520_show(dev, buf, ADP5520_DAYLIGHT_DIM);
  }
  
  static ssize_t adp5520_bl_daylight_dim_store(struct device *dev,
  			struct device_attribute *attr,
  			const char *buf, size_t count)
  {
  	return adp5520_store(dev, buf, count, ADP5520_DAYLIGHT_DIM);
  }
  static DEVICE_ATTR(daylight_dim, 0664, adp5520_bl_daylight_dim_show,
  			adp5520_bl_daylight_dim_store);
  
  static struct attribute *adp5520_bl_attributes[] = {
  	&dev_attr_dark_max.attr,
  	&dev_attr_dark_dim.attr,
  	&dev_attr_office_max.attr,
  	&dev_attr_office_dim.attr,
  	&dev_attr_daylight_max.attr,
  	&dev_attr_daylight_dim.attr,
  	NULL
  };
  
  static const struct attribute_group adp5520_bl_attr_group = {
  	.attrs = adp5520_bl_attributes,
  };
  
  static int adp5520_bl_probe(struct platform_device *pdev)
  {
  	struct backlight_properties props;
  	struct backlight_device *bl;
  	struct adp5520_bl *data;
  	int ret = 0;
  
  	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
  	if (data == NULL)
  		return -ENOMEM;
  
  	data->master = pdev->dev.parent;
  	data->pdata = dev_get_platdata(&pdev->dev);
  
  	if (data->pdata  == NULL) {
  		dev_err(&pdev->dev, "missing platform data\n");
  		return -ENODEV;
  	}
  
  	data->id = pdev->id;
  	data->current_brightness = 0;
  
  	mutex_init(&data->lock);
  
  	memset(&props, 0, sizeof(struct backlight_properties));
  	props.type = BACKLIGHT_RAW;
  	props.max_brightness = ADP5020_MAX_BRIGHTNESS;
  	bl = devm_backlight_device_register(&pdev->dev, pdev->name,
  					data->master, data, &adp5520_bl_ops,
  					&props);
  	if (IS_ERR(bl)) {
  		dev_err(&pdev->dev, "failed to register backlight\n");
  		return PTR_ERR(bl);
  	}
  
  	bl->props.brightness = ADP5020_MAX_BRIGHTNESS;
  	if (data->pdata->en_ambl_sens)
  		ret = sysfs_create_group(&bl->dev.kobj,
  			&adp5520_bl_attr_group);
  
  	if (ret) {
  		dev_err(&pdev->dev, "failed to register sysfs\n");
  		return ret;
  	}
  
  	platform_set_drvdata(pdev, bl);
  	ret = adp5520_bl_setup(bl);
  	if (ret) {
  		dev_err(&pdev->dev, "failed to setup\n");
  		if (data->pdata->en_ambl_sens)
  			sysfs_remove_group(&bl->dev.kobj,
  					&adp5520_bl_attr_group);
  		return ret;
  	}
  
  	backlight_update_status(bl);
  
  	return 0;
  }
  
  static int adp5520_bl_remove(struct platform_device *pdev)
  {
  	struct backlight_device *bl = platform_get_drvdata(pdev);
  	struct adp5520_bl *data = bl_get_data(bl);
  
  	adp5520_clr_bits(data->master, ADP5520_MODE_STATUS, ADP5520_BL_EN);
  
  	if (data->pdata->en_ambl_sens)
  		sysfs_remove_group(&bl->dev.kobj,
  				&adp5520_bl_attr_group);
  
  	return 0;
  }
  
  #ifdef CONFIG_PM_SLEEP
  static int adp5520_bl_suspend(struct device *dev)
  {
  	struct backlight_device *bl = dev_get_drvdata(dev);
  
  	return adp5520_bl_set(bl, 0);
  }
  
  static int adp5520_bl_resume(struct device *dev)
  {
  	struct backlight_device *bl = dev_get_drvdata(dev);
  
  	backlight_update_status(bl);
  	return 0;
  }
  #endif
  
  static SIMPLE_DEV_PM_OPS(adp5520_bl_pm_ops, adp5520_bl_suspend,
  			adp5520_bl_resume);
  
  static struct platform_driver adp5520_bl_driver = {
  	.driver		= {
  		.name	= "adp5520-backlight",
  		.pm	= &adp5520_bl_pm_ops,
  	},
  	.probe		= adp5520_bl_probe,
  	.remove		= adp5520_bl_remove,
  };
  
  module_platform_driver(adp5520_bl_driver);
  
  MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
  MODULE_DESCRIPTION("ADP5520(01) Backlight Driver");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:adp5520-backlight");
  