drivers/video/backlight/sky81452-backlight.c - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

 /*
  * sky81452-backlight.c	SKY81452 backlight driver
  *
  * Copyright 2014 Skyworks Solutions Inc.
  * Author : Gyungoh Yoo <jack.yoo@skyworksinc.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.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License along
  * with this program; if not, see <http://www.gnu.org/licenses/>.
  */

 #include <linux/backlight.h>
 #include <linux/err.h>
 #include <linux/gpio.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/platform_data/sky81452-backlight.h>
 #include <linux/slab.h>

 /* registers */
 #define SKY81452_REG0	0x00
 #define SKY81452_REG1	0x01
 #define SKY81452_REG2	0x02
 #define SKY81452_REG4	0x04
 #define SKY81452_REG5	0x05

 /* bit mask */
 #define SKY81452_CS	0xFF
 #define SKY81452_EN	0x3F
 #define SKY81452_IGPW	0x20
 #define SKY81452_PWMMD	0x10
 #define SKY81452_PHASE	0x08
 #define SKY81452_ILIM	0x04
 #define SKY81452_VSHRT	0x03
 #define SKY81452_OCP	0x80
 #define SKY81452_OTMP	0x40
 #define SKY81452_SHRT	0x3F
 #define SKY81452_OPN	0x3F

 #define SKY81452_DEFAULT_NAME "lcd-backlight"
 #define SKY81452_MAX_BRIGHTNESS	(SKY81452_CS + 1)

 #define CTZ(b) __builtin_ctz(b)

 static int sky81452_bl_update_status(struct backlight_device *bd)
 {
 	const struct sky81452_bl_platform_data *pdata =
 			dev_get_platdata(bd->dev.parent);
 	const unsigned int brightness = (unsigned int)bd->props.brightness;
 	struct regmap *regmap = bl_get_data(bd);
 	int ret;

 	if (brightness > 0) {
 		ret = regmap_write(regmap, SKY81452_REG0, brightness - 1);
 		if (ret < 0)
 			return ret;

 		return regmap_update_bits(regmap, SKY81452_REG1, SKY81452_EN,
 					pdata->enable << CTZ(SKY81452_EN));
 	}

 	return regmap_update_bits(regmap, SKY81452_REG1, SKY81452_EN, 0);
 }

 static const struct backlight_ops sky81452_bl_ops = {
 	.update_status = sky81452_bl_update_status,
 };

 static ssize_t sky81452_bl_store_enable(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
 	struct regmap *regmap = bl_get_data(to_backlight_device(dev));
 	unsigned long value;
 	int ret;

 	ret = kstrtoul(buf, 16, &value);
 	if (ret < 0)
 		return ret;

 	ret = regmap_update_bits(regmap, SKY81452_REG1, SKY81452_EN,
 					value << CTZ(SKY81452_EN));
 	if (ret < 0)
 		return ret;

 	return count;
 }

 static ssize_t sky81452_bl_show_open_short(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct regmap *regmap = bl_get_data(to_backlight_device(dev));
 	unsigned int reg, value = 0;
 	char tmp[3];
 	int i, ret;

 	reg = !strcmp(attr->attr.name, "open") ? SKY81452_REG5 : SKY81452_REG4;
 	ret = regmap_read(regmap, reg, &value);
 	if (ret < 0)
 		return ret;

 	if (value & SKY81452_SHRT) {
 		*buf = 0;
 		for (i = 0; i < 6; i++) {
 			if (value & 0x01) {
 				sprintf(tmp, "%d ", i + 1);
 				strcat(buf, tmp);
 			}
 			value >>= 1;
 		}
 		strcat(buf, "\n");
 	} else {
 		strcpy(buf, "none\n");
 	}

 	return strlen(buf);
 }

 static ssize_t sky81452_bl_show_fault(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct regmap *regmap = bl_get_data(to_backlight_device(dev));
 	unsigned int value = 0;
 	int ret;

 	ret = regmap_read(regmap, SKY81452_REG4, &value);
 	if (ret < 0)
 		return ret;

 	*buf = 0;

 	if (value & SKY81452_OCP)
 		strcat(buf, "over-current ");

 	if (value & SKY81452_OTMP)
 		strcat(buf, "over-temperature");

 	strcat(buf, "\n");
 	return strlen(buf);
 }

 static DEVICE_ATTR(enable, S_IWGRP | S_IWUSR, NULL, sky81452_bl_store_enable);
 static DEVICE_ATTR(open, S_IRUGO, sky81452_bl_show_open_short, NULL);
 static DEVICE_ATTR(short, S_IRUGO, sky81452_bl_show_open_short, NULL);
 static DEVICE_ATTR(fault, S_IRUGO, sky81452_bl_show_fault, NULL);

 static struct attribute *sky81452_bl_attribute[] = {
 	&dev_attr_enable.attr,
 	&dev_attr_open.attr,
 	&dev_attr_short.attr,
 	&dev_attr_fault.attr,
 	NULL
 };

 static const struct attribute_group sky81452_bl_attr_group = {
 	.attrs = sky81452_bl_attribute,
 };

 #ifdef CONFIG_OF
 static struct sky81452_bl_platform_data *sky81452_bl_parse_dt(
 							struct device *dev)
 {
 	struct device_node *np = of_node_get(dev->of_node);
 	struct sky81452_bl_platform_data *pdata;
 	int num_entry;
 	unsigned int sources[6];
 	int ret;

 	if (!np) {
 		dev_err(dev, "backlight node not found.\n");
 		return ERR_PTR(-ENODATA);
 	}

 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata) {
 		of_node_put(np);
 		return ERR_PTR(-ENOMEM);
 	}

 	of_property_read_string(np, "name", &pdata->name);
 	pdata->ignore_pwm = of_property_read_bool(np, "skyworks,ignore-pwm");
 	pdata->dpwm_mode = of_property_read_bool(np, "skyworks,dpwm-mode");
 	pdata->phase_shift = of_property_read_bool(np, "skyworks,phase-shift");
 	pdata->gpio_enable = of_get_gpio(np, 0);

 	ret = of_property_count_u32_elems(np, "led-sources");
 	if (ret < 0) {
 		pdata->enable = SKY81452_EN >> CTZ(SKY81452_EN);
 	} else {
 		num_entry = ret;
 		if (num_entry > 6)
 			num_entry = 6;

 		ret = of_property_read_u32_array(np, "led-sources", sources,
 					num_entry);
 		if (ret < 0) {
 			dev_err(dev, "led-sources node is invalid.\n");
 			of_node_put(np);
 			return ERR_PTR(-EINVAL);
 		}

 		pdata->enable = 0;
 		while (--num_entry)
 			pdata->enable |= (1 << sources[num_entry]);
 	}

 	ret = of_property_read_u32(np,
 			"skyworks,short-detection-threshold-volt",
 			&pdata->short_detection_threshold);
 	if (ret < 0)
 		pdata->short_detection_threshold = 7;

 	ret = of_property_read_u32(np, "skyworks,current-limit-mA",
 			&pdata->boost_current_limit);
 	if (ret < 0)
 		pdata->boost_current_limit = 2750;

 	of_node_put(np);
 	return pdata;
 }
 #else
 static struct sky81452_bl_platform_data *sky81452_bl_parse_dt(
 							struct device *dev)
 {
 	return ERR_PTR(-EINVAL);
 }
 #endif

 static int sky81452_bl_init_device(struct regmap *regmap,
 		struct sky81452_bl_platform_data *pdata)
 {
 	unsigned int value;

 	value = pdata->ignore_pwm ? SKY81452_IGPW : 0;
 	value |= pdata->dpwm_mode ? SKY81452_PWMMD : 0;
 	value |= pdata->phase_shift ? 0 : SKY81452_PHASE;

 	if (pdata->boost_current_limit == 2300)
 		value |= SKY81452_ILIM;
 	else if (pdata->boost_current_limit != 2750)
 		return -EINVAL;

 	if (pdata->short_detection_threshold < 4 ||
 				pdata->short_detection_threshold > 7)
 		return -EINVAL;
 	value |= (7 - pdata->short_detection_threshold) << CTZ(SKY81452_VSHRT);

 	return regmap_write(regmap, SKY81452_REG2, value);
 }

 static int sky81452_bl_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct regmap *regmap = dev_get_drvdata(dev->parent);
 	struct sky81452_bl_platform_data *pdata = dev_get_platdata(dev);
 	struct backlight_device *bd;
 	struct backlight_properties props;
 	const char *name;
 	int ret;

 	if (!pdata) {
 		pdata = sky81452_bl_parse_dt(dev);
 		if (IS_ERR(pdata))
 			return PTR_ERR(pdata);
 	}

 	if (gpio_is_valid(pdata->gpio_enable)) {
 		ret = devm_gpio_request_one(dev, pdata->gpio_enable,
 					GPIOF_OUT_INIT_HIGH, "sky81452-en");
 		if (ret < 0) {
 			dev_err(dev, "failed to request GPIO. err=%d\n", ret);
 			return ret;
 		}
 	}

 	ret = sky81452_bl_init_device(regmap, pdata);
 	if (ret < 0) {
 		dev_err(dev, "failed to initialize. err=%d\n", ret);
 		return ret;
 	}

 	memset(&props, 0, sizeof(props));
 	props.max_brightness = SKY81452_MAX_BRIGHTNESS,
 	name = pdata->name ? pdata->name : SKY81452_DEFAULT_NAME;
 	bd = devm_backlight_device_register(dev, name, dev, regmap,
 						&sky81452_bl_ops, &props);
 	if (IS_ERR(bd)) {
 		dev_err(dev, "failed to register. err=%ld\n", PTR_ERR(bd));
 		return PTR_ERR(bd);
 	}

 	platform_set_drvdata(pdev, bd);

 	ret = sysfs_create_group(&bd->dev.kobj, &sky81452_bl_attr_group);
 	if (ret < 0) {
 		dev_err(dev, "failed to create attribute. err=%d\n", ret);
 		return ret;
 	}

 	return ret;
 }

 static int sky81452_bl_remove(struct platform_device *pdev)
 {
 	const struct sky81452_bl_platform_data *pdata =
 						dev_get_platdata(&pdev->dev);
 	struct backlight_device *bd = platform_get_drvdata(pdev);

 	sysfs_remove_group(&bd->dev.kobj, &sky81452_bl_attr_group);

 	bd->props.power = FB_BLANK_UNBLANK;
 	bd->props.brightness = 0;
 	backlight_update_status(bd);

 	if (gpio_is_valid(pdata->gpio_enable))
 		gpio_set_value_cansleep(pdata->gpio_enable, 0);

 	return 0;
 }

 #ifdef CONFIG_OF
 static const struct of_device_id sky81452_bl_of_match[] = {
 	{ .compatible = "skyworks,sky81452-backlight", },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sky81452_bl_of_match);
 #endif

 static struct platform_driver sky81452_bl_driver = {
 	.driver = {
 		.name = "sky81452-backlight",
 		.of_match_table = of_match_ptr(sky81452_bl_of_match),
 	},
 	.probe = sky81452_bl_probe,
 	.remove = sky81452_bl_remove,
 };

 module_platform_driver(sky81452_bl_driver);

 MODULE_DESCRIPTION("Skyworks SKY81452 backlight driver");
 MODULE_AUTHOR("Gyungoh Yoo <jack.yoo@skyworksinc.com>");
 MODULE_LICENSE("GPL v2");
	/*
	* sky81452-backlight.c SKY81452 backlight driver
	*
	* Copyright 2014 Skyworks Solutions Inc.
	* Author : Gyungoh Yoo <jack.yoo@skyworksinc.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.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License along
	* with this program; if not, see <http://www.gnu.org/licenses/>.
	*/

	#include <linux/backlight.h>
	#include <linux/err.h>
	#include <linux/gpio.h>
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/of_gpio.h>
	#include <linux/platform_device.h>
	#include <linux/regmap.h>
	#include <linux/platform_data/sky81452-backlight.h>
	#include <linux/slab.h>

	/* registers */
	#define SKY81452_REG0 0x00
	#define SKY81452_REG1 0x01
	#define SKY81452_REG2 0x02
	#define SKY81452_REG4 0x04
	#define SKY81452_REG5 0x05

	/* bit mask */
	#define SKY81452_CS 0xFF
	#define SKY81452_EN 0x3F
	#define SKY81452_IGPW 0x20
	#define SKY81452_PWMMD 0x10
	#define SKY81452_PHASE 0x08
	#define SKY81452_ILIM 0x04
	#define SKY81452_VSHRT 0x03
	#define SKY81452_OCP 0x80
	#define SKY81452_OTMP 0x40
	#define SKY81452_SHRT 0x3F
	#define SKY81452_OPN 0x3F

	#define SKY81452_DEFAULT_NAME "lcd-backlight"
	#define SKY81452_MAX_BRIGHTNESS (SKY81452_CS + 1)

	#define CTZ(b) __builtin_ctz(b)

	static int sky81452_bl_update_status(struct backlight_device *bd)
	{
	const struct sky81452_bl_platform_data *pdata =
	dev_get_platdata(bd->dev.parent);
	const unsigned int brightness = (unsigned int)bd->props.brightness;
	struct regmap *regmap = bl_get_data(bd);
	int ret;

	if (brightness > 0) {
	ret = regmap_write(regmap, SKY81452_REG0, brightness - 1);
	if (ret < 0)
	return ret;

	return regmap_update_bits(regmap, SKY81452_REG1, SKY81452_EN,
	pdata->enable << CTZ(SKY81452_EN));
	}

	return regmap_update_bits(regmap, SKY81452_REG1, SKY81452_EN, 0);
	}

	static const struct backlight_ops sky81452_bl_ops = {
	.update_status = sky81452_bl_update_status,
	};

	static ssize_t sky81452_bl_store_enable(struct device *dev,
	struct device_attribute attr, const char buf, size_t count)
	{
	struct regmap *regmap = bl_get_data(to_backlight_device(dev));
	unsigned long value;
	int ret;

	ret = kstrtoul(buf, 16, &value);
	if (ret < 0)
	return ret;

	ret = regmap_update_bits(regmap, SKY81452_REG1, SKY81452_EN,
	value << CTZ(SKY81452_EN));
	if (ret < 0)
	return ret;

	return count;
	}

	static ssize_t sky81452_bl_show_open_short(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct regmap *regmap = bl_get_data(to_backlight_device(dev));
	unsigned int reg, value = 0;
	char tmp[3];
	int i, ret;

	reg = !strcmp(attr->attr.name, "open") ? SKY81452_REG5 : SKY81452_REG4;
	ret = regmap_read(regmap, reg, &value);
	if (ret < 0)
	return ret;

	if (value & SKY81452_SHRT) {
	*buf = 0;
	for (i = 0; i < 6; i++) {
	if (value & 0x01) {
	sprintf(tmp, "%d ", i + 1);
	strcat(buf, tmp);
	}
	value >>= 1;
	}
	strcat(buf, "\n");
	} else {
	strcpy(buf, "none\n");
	}

	return strlen(buf);
	}

	static ssize_t sky81452_bl_show_fault(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct regmap *regmap = bl_get_data(to_backlight_device(dev));
	unsigned int value = 0;
	int ret;

	ret = regmap_read(regmap, SKY81452_REG4, &value);
	if (ret < 0)
	return ret;

	*buf = 0;

	if (value & SKY81452_OCP)
	strcat(buf, "over-current ");

	if (value & SKY81452_OTMP)
	strcat(buf, "over-temperature");

	strcat(buf, "\n");
	return strlen(buf);
	}

	static DEVICE_ATTR(enable, S_IWGRP \| S_IWUSR, NULL, sky81452_bl_store_enable);
	static DEVICE_ATTR(open, S_IRUGO, sky81452_bl_show_open_short, NULL);
	static DEVICE_ATTR(short, S_IRUGO, sky81452_bl_show_open_short, NULL);
	static DEVICE_ATTR(fault, S_IRUGO, sky81452_bl_show_fault, NULL);

	static struct attribute *sky81452_bl_attribute[] = {
	&dev_attr_enable.attr,
	&dev_attr_open.attr,
	&dev_attr_short.attr,
	&dev_attr_fault.attr,
	NULL
	};

	static const struct attribute_group sky81452_bl_attr_group = {
	.attrs = sky81452_bl_attribute,
	};

	#ifdef CONFIG_OF
	static struct sky81452_bl_platform_data *sky81452_bl_parse_dt(
	struct device *dev)
	{
	struct device_node *np = of_node_get(dev->of_node);
	struct sky81452_bl_platform_data *pdata;
	int num_entry;
	unsigned int sources[6];
	int ret;

	if (!np) {
	dev_err(dev, "backlight node not found.\n");
	return ERR_PTR(-ENODATA);
	}

	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata) {
	of_node_put(np);
	return ERR_PTR(-ENOMEM);
	}

	of_property_read_string(np, "name", &pdata->name);
	pdata->ignore_pwm = of_property_read_bool(np, "skyworks,ignore-pwm");
	pdata->dpwm_mode = of_property_read_bool(np, "skyworks,dpwm-mode");
	pdata->phase_shift = of_property_read_bool(np, "skyworks,phase-shift");
	pdata->gpio_enable = of_get_gpio(np, 0);

	ret = of_property_count_u32_elems(np, "led-sources");
	if (ret < 0) {
	pdata->enable = SKY81452_EN >> CTZ(SKY81452_EN);
	} else {
	num_entry = ret;
	if (num_entry > 6)
	num_entry = 6;

	ret = of_property_read_u32_array(np, "led-sources", sources,
	num_entry);
	if (ret < 0) {
	dev_err(dev, "led-sources node is invalid.\n");
	of_node_put(np);
	return ERR_PTR(-EINVAL);
	}

	pdata->enable = 0;
	while (--num_entry)
	pdata->enable \|= (1 << sources[num_entry]);
	}

	ret = of_property_read_u32(np,
	"skyworks,short-detection-threshold-volt",
	&pdata->short_detection_threshold);
	if (ret < 0)
	pdata->short_detection_threshold = 7;

	ret = of_property_read_u32(np, "skyworks,current-limit-mA",
	&pdata->boost_current_limit);
	if (ret < 0)
	pdata->boost_current_limit = 2750;

	of_node_put(np);
	return pdata;
	}
	#else
	static struct sky81452_bl_platform_data *sky81452_bl_parse_dt(
	struct device *dev)
	{
	return ERR_PTR(-EINVAL);
	}
	#endif

	static int sky81452_bl_init_device(struct regmap *regmap,
	struct sky81452_bl_platform_data *pdata)
	{
	unsigned int value;

	value = pdata->ignore_pwm ? SKY81452_IGPW : 0;
	value \|= pdata->dpwm_mode ? SKY81452_PWMMD : 0;
	value \|= pdata->phase_shift ? 0 : SKY81452_PHASE;

	if (pdata->boost_current_limit == 2300)
	value \|= SKY81452_ILIM;
	else if (pdata->boost_current_limit != 2750)
	return -EINVAL;

	if (pdata->short_detection_threshold < 4 \|\|
	pdata->short_detection_threshold > 7)
	return -EINVAL;
	value \|= (7 - pdata->short_detection_threshold) << CTZ(SKY81452_VSHRT);

	return regmap_write(regmap, SKY81452_REG2, value);
	}

	static int sky81452_bl_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct regmap *regmap = dev_get_drvdata(dev->parent);
	struct sky81452_bl_platform_data *pdata = dev_get_platdata(dev);
	struct backlight_device *bd;
	struct backlight_properties props;
	const char *name;
	int ret;

	if (!pdata) {
	pdata = sky81452_bl_parse_dt(dev);
	if (IS_ERR(pdata))
	return PTR_ERR(pdata);
	}

	if (gpio_is_valid(pdata->gpio_enable)) {
	ret = devm_gpio_request_one(dev, pdata->gpio_enable,
	GPIOF_OUT_INIT_HIGH, "sky81452-en");
	if (ret < 0) {
	dev_err(dev, "failed to request GPIO. err=%d\n", ret);
	return ret;
	}
	}

	ret = sky81452_bl_init_device(regmap, pdata);
	if (ret < 0) {
	dev_err(dev, "failed to initialize. err=%d\n", ret);
	return ret;
	}

	memset(&props, 0, sizeof(props));
	props.max_brightness = SKY81452_MAX_BRIGHTNESS,
	name = pdata->name ? pdata->name : SKY81452_DEFAULT_NAME;
	bd = devm_backlight_device_register(dev, name, dev, regmap,
	&sky81452_bl_ops, &props);
	if (IS_ERR(bd)) {
	dev_err(dev, "failed to register. err=%ld\n", PTR_ERR(bd));
	return PTR_ERR(bd);
	}

	platform_set_drvdata(pdev, bd);

	ret = sysfs_create_group(&bd->dev.kobj, &sky81452_bl_attr_group);
	if (ret < 0) {
	dev_err(dev, "failed to create attribute. err=%d\n", ret);
	return ret;
	}

	return ret;
	}

	static int sky81452_bl_remove(struct platform_device *pdev)
	{
	const struct sky81452_bl_platform_data *pdata =
	dev_get_platdata(&pdev->dev);
	struct backlight_device *bd = platform_get_drvdata(pdev);

	sysfs_remove_group(&bd->dev.kobj, &sky81452_bl_attr_group);

	bd->props.power = FB_BLANK_UNBLANK;
	bd->props.brightness = 0;
	backlight_update_status(bd);

	if (gpio_is_valid(pdata->gpio_enable))
	gpio_set_value_cansleep(pdata->gpio_enable, 0);

	return 0;
	}

	#ifdef CONFIG_OF
	static const struct of_device_id sky81452_bl_of_match[] = {
	{ .compatible = "skyworks,sky81452-backlight", },
	{ }
	};
	MODULE_DEVICE_TABLE(of, sky81452_bl_of_match);
	#endif

	static struct platform_driver sky81452_bl_driver = {
	.driver = {
	.name = "sky81452-backlight",
	.of_match_table = of_match_ptr(sky81452_bl_of_match),
	},
	.probe = sky81452_bl_probe,
	.remove = sky81452_bl_remove,
	};

	module_platform_driver(sky81452_bl_driver);

	MODULE_DESCRIPTION("Skyworks SKY81452 backlight driver");
	MODULE_AUTHOR("Gyungoh Yoo <jack.yoo@skyworksinc.com>");
	MODULE_LICENSE("GPL v2");