drivers/leds/leds-mt6323.c - linux - Git at Google

 /*
  * LED driver for Mediatek MT6323 PMIC
  *
  * Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation; either version 2 of
  * the License, or (at your option) any later version.
  *
  * 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.
  */
 #include <linux/kernel.h>
 #include <linux/leds.h>
 #include <linux/mfd/mt6323/registers.h>
 #include <linux/mfd/mt6397/core.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>

 /*
  * Register field for MT6323_TOP_CKPDN0 to enable
  * 32K clock common for LED device.
  */
 #define MT6323_RG_DRV_32K_CK_PDN	BIT(11)
 #define MT6323_RG_DRV_32K_CK_PDN_MASK	BIT(11)

 /*
  * Register field for MT6323_TOP_CKPDN2 to enable
  * individual clock for LED device.
  */
 #define MT6323_RG_ISINK_CK_PDN(i)	BIT(i)
 #define MT6323_RG_ISINK_CK_PDN_MASK(i)	BIT(i)

 /*
  * Register field for MT6323_TOP_CKCON1 to select
  * clock source.
  */
 #define MT6323_RG_ISINK_CK_SEL_MASK(i)	(BIT(10) << (i))

 /*
  * Register for MT6323_ISINK_CON0 to setup the
  * duty cycle of the blink.
  */
 #define MT6323_ISINK_CON0(i)		(MT6323_ISINK0_CON0 + 0x8 * (i))
 #define MT6323_ISINK_DIM_DUTY_MASK	(0x1f << 8)
 #define MT6323_ISINK_DIM_DUTY(i)	(((i) << 8) & \
 					MT6323_ISINK_DIM_DUTY_MASK)

 /* Register to setup the period of the blink. */
 #define MT6323_ISINK_CON1(i)		(MT6323_ISINK0_CON1 + 0x8 * (i))
 #define MT6323_ISINK_DIM_FSEL_MASK	(0xffff)
 #define MT6323_ISINK_DIM_FSEL(i)	((i) & MT6323_ISINK_DIM_FSEL_MASK)

 /* Register to control the brightness. */
 #define MT6323_ISINK_CON2(i)		(MT6323_ISINK0_CON2 + 0x8 * (i))
 #define MT6323_ISINK_CH_STEP_SHIFT	12
 #define MT6323_ISINK_CH_STEP_MASK	(0x7 << 12)
 #define MT6323_ISINK_CH_STEP(i)		(((i) << 12) & \
 					MT6323_ISINK_CH_STEP_MASK)
 #define MT6323_ISINK_SFSTR0_TC_MASK	(0x3 << 1)
 #define MT6323_ISINK_SFSTR0_TC(i)	(((i) << 1) & \
 					MT6323_ISINK_SFSTR0_TC_MASK)
 #define MT6323_ISINK_SFSTR0_EN_MASK	BIT(0)
 #define MT6323_ISINK_SFSTR0_EN		BIT(0)

 /* Register to LED channel enablement. */
 #define MT6323_ISINK_CH_EN_MASK(i)	BIT(i)
 #define MT6323_ISINK_CH_EN(i)		BIT(i)

 #define MT6323_MAX_PERIOD		10000
 #define MT6323_MAX_LEDS			4
 #define MT6323_MAX_BRIGHTNESS		6
 #define MT6323_UNIT_DUTY		3125
 #define MT6323_CAL_HW_DUTY(o, p)	DIV_ROUND_CLOSEST((o) * 100000ul,\
 					(p) * MT6323_UNIT_DUTY)

 struct mt6323_leds;

 /**
  * struct mt6323_led - state container for the LED device
  * @id:			the identifier in MT6323 LED device
  * @parent:		the pointer to MT6323 LED controller
  * @cdev:		LED class device for this LED device
  * @current_brightness: current state of the LED device
  */
 struct mt6323_led {
 	int			id;
 	struct mt6323_leds	*parent;
 	struct led_classdev	cdev;
 	enum led_brightness	current_brightness;
 };

 /**
  * struct mt6323_leds -	state container for holding LED controller
  *			of the driver
  * @dev:		the device pointer
  * @hw:			the underlying hardware providing shared
  *			bus for the register operations
  * @lock:		the lock among process context
  * @led:		the array that contains the state of individual
  *			LED device
  */
 struct mt6323_leds {
 	struct device		*dev;
 	struct mt6397_chip	*hw;
 	/* protect among process context */
 	struct mutex		lock;
 	struct mt6323_led	*led[MT6323_MAX_LEDS];
 };

 static int mt6323_led_hw_brightness(struct led_classdev *cdev,
 				    enum led_brightness brightness)
 {
 	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
 	struct mt6323_leds *leds = led->parent;
 	struct regmap *regmap = leds->hw->regmap;
 	u32 con2_mask = 0, con2_val = 0;
 	int ret;

 	/*
 	 * Setup current output for the corresponding
 	 * brightness level.
 	 */
 	con2_mask |= MT6323_ISINK_CH_STEP_MASK |
 		     MT6323_ISINK_SFSTR0_TC_MASK |
 		     MT6323_ISINK_SFSTR0_EN_MASK;
 	con2_val |=  MT6323_ISINK_CH_STEP(brightness - 1) |
 		     MT6323_ISINK_SFSTR0_TC(2) |
 		     MT6323_ISINK_SFSTR0_EN;

 	ret = regmap_update_bits(regmap, MT6323_ISINK_CON2(led->id),
 				 con2_mask, con2_val);
 	return ret;
 }

 static int mt6323_led_hw_off(struct led_classdev *cdev)
 {
 	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
 	struct mt6323_leds *leds = led->parent;
 	struct regmap *regmap = leds->hw->regmap;
 	unsigned int status;
 	int ret;

 	status = MT6323_ISINK_CH_EN(led->id);
 	ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL,
 				 MT6323_ISINK_CH_EN_MASK(led->id), ~status);
 	if (ret < 0)
 		return ret;

 	usleep_range(100, 300);
 	ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2,
 				 MT6323_RG_ISINK_CK_PDN_MASK(led->id),
 				 MT6323_RG_ISINK_CK_PDN(led->id));
 	if (ret < 0)
 		return ret;

 	return 0;
 }

 static enum led_brightness
 mt6323_get_led_hw_brightness(struct led_classdev *cdev)
 {
 	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
 	struct mt6323_leds *leds = led->parent;
 	struct regmap *regmap = leds->hw->regmap;
 	unsigned int status;
 	int ret;

 	ret = regmap_read(regmap, MT6323_TOP_CKPDN2, &status);
 	if (ret < 0)
 		return ret;

 	if (status & MT6323_RG_ISINK_CK_PDN_MASK(led->id))
 		return 0;

 	ret = regmap_read(regmap, MT6323_ISINK_EN_CTRL, &status);
 	if (ret < 0)
 		return ret;

 	if (!(status & MT6323_ISINK_CH_EN(led->id)))
 		return 0;

 	ret = regmap_read(regmap, MT6323_ISINK_CON2(led->id), &status);
 	if (ret < 0)
 		return ret;

 	return  ((status & MT6323_ISINK_CH_STEP_MASK)
 		  >> MT6323_ISINK_CH_STEP_SHIFT) + 1;
 }

 static int mt6323_led_hw_on(struct led_classdev *cdev,
 			    enum led_brightness brightness)
 {
 	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
 	struct mt6323_leds *leds = led->parent;
 	struct regmap *regmap = leds->hw->regmap;
 	unsigned int status;
 	int ret;

 	/*
 	 * Setup required clock source, enable the corresponding
 	 * clock and channel and let work with continuous blink as
 	 * the default.
 	 */
 	ret = regmap_update_bits(regmap, MT6323_TOP_CKCON1,
 				 MT6323_RG_ISINK_CK_SEL_MASK(led->id), 0);
 	if (ret < 0)
 		return ret;

 	status = MT6323_RG_ISINK_CK_PDN(led->id);
 	ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2,
 				 MT6323_RG_ISINK_CK_PDN_MASK(led->id),
 				 ~status);
 	if (ret < 0)
 		return ret;

 	usleep_range(100, 300);

 	ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL,
 				 MT6323_ISINK_CH_EN_MASK(led->id),
 				 MT6323_ISINK_CH_EN(led->id));
 	if (ret < 0)
 		return ret;

 	ret = mt6323_led_hw_brightness(cdev, brightness);
 	if (ret < 0)
 		return ret;

 	ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id),
 				 MT6323_ISINK_DIM_DUTY_MASK,
 				 MT6323_ISINK_DIM_DUTY(31));
 	if (ret < 0)
 		return ret;

 	ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id),
 				 MT6323_ISINK_DIM_FSEL_MASK,
 				 MT6323_ISINK_DIM_FSEL(1000));
 	if (ret < 0)
 		return ret;

 	return 0;
 }

 static int mt6323_led_set_blink(struct led_classdev *cdev,
 				unsigned long *delay_on,
 				unsigned long *delay_off)
 {
 	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
 	struct mt6323_leds *leds = led->parent;
 	struct regmap *regmap = leds->hw->regmap;
 	unsigned long period;
 	u8 duty_hw;
 	int ret;

 	/*
 	 * Units are in ms, if over the hardware able
 	 * to support, fallback into software blink
 	 */
 	period = *delay_on + *delay_off;

 	if (period > MT6323_MAX_PERIOD)
 		return -EINVAL;

 	/*
 	 * LED subsystem requires a default user
 	 * friendly blink pattern for the LED so using
 	 * 1Hz duty cycle 50% here if without specific
 	 * value delay_on and delay off being assigned.
 	 */
 	if (!*delay_on && !*delay_off) {
 		*delay_on = 500;
 		*delay_off = 500;
 	}

 	/*
 	 * Calculate duty_hw based on the percentage of period during
 	 * which the led is ON.
 	 */
 	duty_hw = MT6323_CAL_HW_DUTY(*delay_on, period);

 	/* hardware doesn't support zero duty cycle. */
 	if (!duty_hw)
 		return -EINVAL;

 	mutex_lock(&leds->lock);
 	/*
 	 * Set max_brightness as the software blink behavior
 	 * when no blink brightness.
 	 */
 	if (!led->current_brightness) {
 		ret = mt6323_led_hw_on(cdev, cdev->max_brightness);
 		if (ret < 0)
 			goto out;
 		led->current_brightness = cdev->max_brightness;
 	}

 	ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id),
 				 MT6323_ISINK_DIM_DUTY_MASK,
 				 MT6323_ISINK_DIM_DUTY(duty_hw - 1));
 	if (ret < 0)
 		goto out;

 	ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id),
 				 MT6323_ISINK_DIM_FSEL_MASK,
 				 MT6323_ISINK_DIM_FSEL(period - 1));
 out:
 	mutex_unlock(&leds->lock);

 	return ret;
 }

 static int mt6323_led_set_brightness(struct led_classdev *cdev,
 				     enum led_brightness brightness)
 {
 	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
 	struct mt6323_leds *leds = led->parent;
 	int ret;

 	mutex_lock(&leds->lock);

 	if (!led->current_brightness && brightness) {
 		ret = mt6323_led_hw_on(cdev, brightness);
 		if (ret < 0)
 			goto out;
 	} else if (brightness) {
 		ret = mt6323_led_hw_brightness(cdev, brightness);
 		if (ret < 0)
 			goto out;
 	} else {
 		ret = mt6323_led_hw_off(cdev);
 		if (ret < 0)
 			goto out;
 	}

 	led->current_brightness = brightness;
 out:
 	mutex_unlock(&leds->lock);

 	return ret;
 }

 static int mt6323_led_set_dt_default(struct led_classdev *cdev,
 				     struct device_node *np)
 {
 	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
 	const char *state;
 	int ret = 0;

 	led->cdev.name = of_get_property(np, "label", NULL) ? : np->name;
 	led->cdev.default_trigger = of_get_property(np,
 						    "linux,default-trigger",
 						    NULL);

 	state = of_get_property(np, "default-state", NULL);
 	if (state) {
 		if (!strcmp(state, "keep")) {
 			ret = mt6323_get_led_hw_brightness(cdev);
 			if (ret < 0)
 				return ret;
 			led->current_brightness = ret;
 			ret = 0;
 		} else if (!strcmp(state, "on")) {
 			ret =
 			mt6323_led_set_brightness(cdev, cdev->max_brightness);
 		} else  {
 			ret = mt6323_led_set_brightness(cdev, LED_OFF);
 		}
 	}

 	return ret;
 }

 static int mt6323_led_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *np = pdev->dev.of_node;
 	struct device_node *child;
 	struct mt6397_chip *hw = dev_get_drvdata(pdev->dev.parent);
 	struct mt6323_leds *leds;
 	struct mt6323_led *led;
 	int ret;
 	unsigned int status;
 	u32 reg;

 	leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL);
 	if (!leds)
 		return -ENOMEM;

 	platform_set_drvdata(pdev, leds);
 	leds->dev = dev;

 	/*
 	 * leds->hw points to the underlying bus for the register
 	 * controlled.
 	 */
 	leds->hw = hw;
 	mutex_init(&leds->lock);

 	status = MT6323_RG_DRV_32K_CK_PDN;
 	ret = regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
 				 MT6323_RG_DRV_32K_CK_PDN_MASK, ~status);
 	if (ret < 0) {
 		dev_err(leds->dev,
 			"Failed to update MT6323_TOP_CKPDN0 Register\n");
 		return ret;
 	}

 	for_each_available_child_of_node(np, child) {
 		ret = of_property_read_u32(child, "reg", &reg);
 		if (ret) {
 			dev_err(dev, "Failed to read led 'reg' property\n");
 			goto put_child_node;
 		}

 		if (reg >= MT6323_MAX_LEDS || leds->led[reg]) {
 			dev_err(dev, "Invalid led reg %u\n", reg);
 			ret = -EINVAL;
 			goto put_child_node;
 		}

 		led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
 		if (!led) {
 			ret = -ENOMEM;
 			goto put_child_node;
 		}

 		leds->led[reg] = led;
 		leds->led[reg]->id = reg;
 		leds->led[reg]->cdev.max_brightness = MT6323_MAX_BRIGHTNESS;
 		leds->led[reg]->cdev.brightness_set_blocking =
 					mt6323_led_set_brightness;
 		leds->led[reg]->cdev.blink_set = mt6323_led_set_blink;
 		leds->led[reg]->cdev.brightness_get =
 					mt6323_get_led_hw_brightness;
 		leds->led[reg]->parent = leds;

 		ret = mt6323_led_set_dt_default(&leds->led[reg]->cdev, child);
 		if (ret < 0) {
 			dev_err(leds->dev,
 				"Failed to LED set default from devicetree\n");
 			goto put_child_node;
 		}

 		ret = devm_led_classdev_register(dev, &leds->led[reg]->cdev);
 		if (ret) {
 			dev_err(&pdev->dev, "Failed to register LED: %d\n",
 				ret);
 			goto put_child_node;
 		}
 		leds->led[reg]->cdev.dev->of_node = child;
 	}

 	return 0;

 put_child_node:
 	of_node_put(child);
 	return ret;
 }

 static int mt6323_led_remove(struct platform_device *pdev)
 {
 	struct mt6323_leds *leds = platform_get_drvdata(pdev);
 	int i;

 	/* Turn the LEDs off on driver removal. */
 	for (i = 0 ; leds->led[i] ; i++)
 		mt6323_led_hw_off(&leds->led[i]->cdev);

 	regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
 			   MT6323_RG_DRV_32K_CK_PDN_MASK,
 			   MT6323_RG_DRV_32K_CK_PDN);

 	mutex_destroy(&leds->lock);

 	return 0;
 }

 static const struct of_device_id mt6323_led_dt_match[] = {
 	{ .compatible = "mediatek,mt6323-led" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, mt6323_led_dt_match);

 static struct platform_driver mt6323_led_driver = {
 	.probe		= mt6323_led_probe,
 	.remove		= mt6323_led_remove,
 	.driver		= {
 		.name	= "mt6323-led",
 		.of_match_table = mt6323_led_dt_match,
 	},
 };

 module_platform_driver(mt6323_led_driver);

 MODULE_DESCRIPTION("LED driver for Mediatek MT6323 PMIC");
 MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
 MODULE_LICENSE("GPL");
	/*
	* LED driver for Mediatek MT6323 PMIC
	*
	* Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License as
	* published by the Free Software Foundation; either version 2 of
	* the License, or (at your option) any later version.
	*
	* 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.
	*/
	#include <linux/kernel.h>
	#include <linux/leds.h>
	#include <linux/mfd/mt6323/registers.h>
	#include <linux/mfd/mt6397/core.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/regmap.h>

	/*
	* Register field for MT6323_TOP_CKPDN0 to enable
	* 32K clock common for LED device.
	*/
	#define MT6323_RG_DRV_32K_CK_PDN BIT(11)
	#define MT6323_RG_DRV_32K_CK_PDN_MASK BIT(11)

	/*
	* Register field for MT6323_TOP_CKPDN2 to enable
	* individual clock for LED device.
	*/
	#define MT6323_RG_ISINK_CK_PDN(i) BIT(i)
	#define MT6323_RG_ISINK_CK_PDN_MASK(i) BIT(i)

	/*
	* Register field for MT6323_TOP_CKCON1 to select
	* clock source.
	*/
	#define MT6323_RG_ISINK_CK_SEL_MASK(i) (BIT(10) << (i))

	/*
	* Register for MT6323_ISINK_CON0 to setup the
	* duty cycle of the blink.
	*/
	#define MT6323_ISINK_CON0(i) (MT6323_ISINK0_CON0 + 0x8 * (i))
	#define MT6323_ISINK_DIM_DUTY_MASK (0x1f << 8)
	#define MT6323_ISINK_DIM_DUTY(i) (((i) << 8) & \
	MT6323_ISINK_DIM_DUTY_MASK)

	/* Register to setup the period of the blink. */
	#define MT6323_ISINK_CON1(i) (MT6323_ISINK0_CON1 + 0x8 * (i))
	#define MT6323_ISINK_DIM_FSEL_MASK (0xffff)
	#define MT6323_ISINK_DIM_FSEL(i) ((i) & MT6323_ISINK_DIM_FSEL_MASK)

	/* Register to control the brightness. */
	#define MT6323_ISINK_CON2(i) (MT6323_ISINK0_CON2 + 0x8 * (i))
	#define MT6323_ISINK_CH_STEP_SHIFT 12
	#define MT6323_ISINK_CH_STEP_MASK (0x7 << 12)
	#define MT6323_ISINK_CH_STEP(i) (((i) << 12) & \
	MT6323_ISINK_CH_STEP_MASK)
	#define MT6323_ISINK_SFSTR0_TC_MASK (0x3 << 1)
	#define MT6323_ISINK_SFSTR0_TC(i) (((i) << 1) & \
	MT6323_ISINK_SFSTR0_TC_MASK)
	#define MT6323_ISINK_SFSTR0_EN_MASK BIT(0)
	#define MT6323_ISINK_SFSTR0_EN BIT(0)

	/* Register to LED channel enablement. */
	#define MT6323_ISINK_CH_EN_MASK(i) BIT(i)
	#define MT6323_ISINK_CH_EN(i) BIT(i)

	#define MT6323_MAX_PERIOD 10000
	#define MT6323_MAX_LEDS 4
	#define MT6323_MAX_BRIGHTNESS 6
	#define MT6323_UNIT_DUTY 3125
	#define MT6323_CAL_HW_DUTY(o, p) DIV_ROUND_CLOSEST((o) * 100000ul,\
	(p) * MT6323_UNIT_DUTY)

	struct mt6323_leds;

	/**
	* struct mt6323_led - state container for the LED device
	* @id: the identifier in MT6323 LED device
	* @parent: the pointer to MT6323 LED controller
	* @cdev: LED class device for this LED device
	* @current_brightness: current state of the LED device
	*/
	struct mt6323_led {
	int id;
	struct mt6323_leds *parent;
	struct led_classdev cdev;
	enum led_brightness current_brightness;
	};

	/**
	* struct mt6323_leds - state container for holding LED controller
	* of the driver
	* @dev: the device pointer
	* @hw: the underlying hardware providing shared
	* bus for the register operations
	* @lock: the lock among process context
	* @led: the array that contains the state of individual
	* LED device
	*/
	struct mt6323_leds {
	struct device *dev;
	struct mt6397_chip *hw;
	/* protect among process context */
	struct mutex lock;
	struct mt6323_led *led[MT6323_MAX_LEDS];
	};

	static int mt6323_led_hw_brightness(struct led_classdev *cdev,
	enum led_brightness brightness)
	{
	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
	struct mt6323_leds *leds = led->parent;
	struct regmap *regmap = leds->hw->regmap;
	u32 con2_mask = 0, con2_val = 0;
	int ret;

	/*
	* Setup current output for the corresponding
	* brightness level.
	*/
	con2_mask \|= MT6323_ISINK_CH_STEP_MASK \|
	MT6323_ISINK_SFSTR0_TC_MASK \|
	MT6323_ISINK_SFSTR0_EN_MASK;
	con2_val \|= MT6323_ISINK_CH_STEP(brightness - 1) \|
	MT6323_ISINK_SFSTR0_TC(2) \|
	MT6323_ISINK_SFSTR0_EN;

	ret = regmap_update_bits(regmap, MT6323_ISINK_CON2(led->id),
	con2_mask, con2_val);
	return ret;
	}

	static int mt6323_led_hw_off(struct led_classdev *cdev)
	{
	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
	struct mt6323_leds *leds = led->parent;
	struct regmap *regmap = leds->hw->regmap;
	unsigned int status;
	int ret;

	status = MT6323_ISINK_CH_EN(led->id);
	ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL,
	MT6323_ISINK_CH_EN_MASK(led->id), ~status);
	if (ret < 0)
	return ret;

	usleep_range(100, 300);
	ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2,
	MT6323_RG_ISINK_CK_PDN_MASK(led->id),
	MT6323_RG_ISINK_CK_PDN(led->id));
	if (ret < 0)
	return ret;

	return 0;
	}

	static enum led_brightness
	mt6323_get_led_hw_brightness(struct led_classdev *cdev)
	{
	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
	struct mt6323_leds *leds = led->parent;
	struct regmap *regmap = leds->hw->regmap;
	unsigned int status;
	int ret;

	ret = regmap_read(regmap, MT6323_TOP_CKPDN2, &status);
	if (ret < 0)
	return ret;

	if (status & MT6323_RG_ISINK_CK_PDN_MASK(led->id))
	return 0;

	ret = regmap_read(regmap, MT6323_ISINK_EN_CTRL, &status);
	if (ret < 0)
	return ret;

	if (!(status & MT6323_ISINK_CH_EN(led->id)))
	return 0;

	ret = regmap_read(regmap, MT6323_ISINK_CON2(led->id), &status);
	if (ret < 0)
	return ret;

	return ((status & MT6323_ISINK_CH_STEP_MASK)
	>> MT6323_ISINK_CH_STEP_SHIFT) + 1;
	}

	static int mt6323_led_hw_on(struct led_classdev *cdev,
	enum led_brightness brightness)
	{
	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
	struct mt6323_leds *leds = led->parent;
	struct regmap *regmap = leds->hw->regmap;
	unsigned int status;
	int ret;

	/*
	* Setup required clock source, enable the corresponding
	* clock and channel and let work with continuous blink as
	* the default.
	*/
	ret = regmap_update_bits(regmap, MT6323_TOP_CKCON1,
	MT6323_RG_ISINK_CK_SEL_MASK(led->id), 0);
	if (ret < 0)
	return ret;

	status = MT6323_RG_ISINK_CK_PDN(led->id);
	ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2,
	MT6323_RG_ISINK_CK_PDN_MASK(led->id),
	~status);
	if (ret < 0)
	return ret;

	usleep_range(100, 300);

	ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL,
	MT6323_ISINK_CH_EN_MASK(led->id),
	MT6323_ISINK_CH_EN(led->id));
	if (ret < 0)
	return ret;

	ret = mt6323_led_hw_brightness(cdev, brightness);
	if (ret < 0)
	return ret;

	ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id),
	MT6323_ISINK_DIM_DUTY_MASK,
	MT6323_ISINK_DIM_DUTY(31));
	if (ret < 0)
	return ret;

	ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id),
	MT6323_ISINK_DIM_FSEL_MASK,
	MT6323_ISINK_DIM_FSEL(1000));
	if (ret < 0)
	return ret;

	return 0;
	}

	static int mt6323_led_set_blink(struct led_classdev *cdev,
	unsigned long *delay_on,
	unsigned long *delay_off)
	{
	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
	struct mt6323_leds *leds = led->parent;
	struct regmap *regmap = leds->hw->regmap;
	unsigned long period;
	u8 duty_hw;
	int ret;

	/*
	* Units are in ms, if over the hardware able
	* to support, fallback into software blink
	*/
	period = delay_on + delay_off;

	if (period > MT6323_MAX_PERIOD)
	return -EINVAL;

	/*
	* LED subsystem requires a default user
	* friendly blink pattern for the LED so using
	* 1Hz duty cycle 50% here if without specific
	* value delay_on and delay off being assigned.
	*/
	if (!delay_on && !delay_off) {
	*delay_on = 500;
	*delay_off = 500;
	}

	/*
	* Calculate duty_hw based on the percentage of period during
	* which the led is ON.
	*/
	duty_hw = MT6323_CAL_HW_DUTY(*delay_on, period);

	/* hardware doesn't support zero duty cycle. */
	if (!duty_hw)
	return -EINVAL;

	mutex_lock(&leds->lock);
	/*
	* Set max_brightness as the software blink behavior
	* when no blink brightness.
	*/
	if (!led->current_brightness) {
	ret = mt6323_led_hw_on(cdev, cdev->max_brightness);
	if (ret < 0)
	goto out;
	led->current_brightness = cdev->max_brightness;
	}

	ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id),
	MT6323_ISINK_DIM_DUTY_MASK,
	MT6323_ISINK_DIM_DUTY(duty_hw - 1));
	if (ret < 0)
	goto out;

	ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id),
	MT6323_ISINK_DIM_FSEL_MASK,
	MT6323_ISINK_DIM_FSEL(period - 1));
	out:
	mutex_unlock(&leds->lock);

	return ret;
	}

	static int mt6323_led_set_brightness(struct led_classdev *cdev,
	enum led_brightness brightness)
	{
	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
	struct mt6323_leds *leds = led->parent;
	int ret;

	mutex_lock(&leds->lock);

	if (!led->current_brightness && brightness) {
	ret = mt6323_led_hw_on(cdev, brightness);
	if (ret < 0)
	goto out;
	} else if (brightness) {
	ret = mt6323_led_hw_brightness(cdev, brightness);
	if (ret < 0)
	goto out;
	} else {
	ret = mt6323_led_hw_off(cdev);
	if (ret < 0)
	goto out;
	}

	led->current_brightness = brightness;
	out:
	mutex_unlock(&leds->lock);

	return ret;
	}

	static int mt6323_led_set_dt_default(struct led_classdev *cdev,
	struct device_node *np)
	{
	struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
	const char *state;
	int ret = 0;

	led->cdev.name = of_get_property(np, "label", NULL) ? : np->name;
	led->cdev.default_trigger = of_get_property(np,
	"linux,default-trigger",
	NULL);

	state = of_get_property(np, "default-state", NULL);
	if (state) {
	if (!strcmp(state, "keep")) {
	ret = mt6323_get_led_hw_brightness(cdev);
	if (ret < 0)
	return ret;
	led->current_brightness = ret;
	ret = 0;
	} else if (!strcmp(state, "on")) {
	ret =
	mt6323_led_set_brightness(cdev, cdev->max_brightness);
	} else {
	ret = mt6323_led_set_brightness(cdev, LED_OFF);
	}
	}

	return ret;
	}

	static int mt6323_led_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct device_node *np = pdev->dev.of_node;
	struct device_node *child;
	struct mt6397_chip *hw = dev_get_drvdata(pdev->dev.parent);
	struct mt6323_leds *leds;
	struct mt6323_led *led;
	int ret;
	unsigned int status;
	u32 reg;

	leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL);
	if (!leds)
	return -ENOMEM;

	platform_set_drvdata(pdev, leds);
	leds->dev = dev;

	/*
	* leds->hw points to the underlying bus for the register
	* controlled.
	*/
	leds->hw = hw;
	mutex_init(&leds->lock);

	status = MT6323_RG_DRV_32K_CK_PDN;
	ret = regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
	MT6323_RG_DRV_32K_CK_PDN_MASK, ~status);
	if (ret < 0) {
	dev_err(leds->dev,
	"Failed to update MT6323_TOP_CKPDN0 Register\n");
	return ret;
	}

	for_each_available_child_of_node(np, child) {
	ret = of_property_read_u32(child, "reg", &reg);
	if (ret) {
	dev_err(dev, "Failed to read led 'reg' property\n");
	goto put_child_node;
	}

	if (reg >= MT6323_MAX_LEDS \|\| leds->led[reg]) {
	dev_err(dev, "Invalid led reg %u\n", reg);
	ret = -EINVAL;
	goto put_child_node;
	}

	led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
	if (!led) {
	ret = -ENOMEM;
	goto put_child_node;
	}

	leds->led[reg] = led;
	leds->led[reg]->id = reg;
	leds->led[reg]->cdev.max_brightness = MT6323_MAX_BRIGHTNESS;
	leds->led[reg]->cdev.brightness_set_blocking =
	mt6323_led_set_brightness;
	leds->led[reg]->cdev.blink_set = mt6323_led_set_blink;
	leds->led[reg]->cdev.brightness_get =
	mt6323_get_led_hw_brightness;
	leds->led[reg]->parent = leds;

	ret = mt6323_led_set_dt_default(&leds->led[reg]->cdev, child);
	if (ret < 0) {
	dev_err(leds->dev,
	"Failed to LED set default from devicetree\n");
	goto put_child_node;
	}

	ret = devm_led_classdev_register(dev, &leds->led[reg]->cdev);
	if (ret) {
	dev_err(&pdev->dev, "Failed to register LED: %d\n",
	ret);
	goto put_child_node;
	}
	leds->led[reg]->cdev.dev->of_node = child;
	}

	return 0;

	put_child_node:
	of_node_put(child);
	return ret;
	}

	static int mt6323_led_remove(struct platform_device *pdev)
	{
	struct mt6323_leds *leds = platform_get_drvdata(pdev);
	int i;

	/* Turn the LEDs off on driver removal. */
	for (i = 0 ; leds->led[i] ; i++)
	mt6323_led_hw_off(&leds->led[i]->cdev);

	regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
	MT6323_RG_DRV_32K_CK_PDN_MASK,
	MT6323_RG_DRV_32K_CK_PDN);

	mutex_destroy(&leds->lock);

	return 0;
	}

	static const struct of_device_id mt6323_led_dt_match[] = {
	{ .compatible = "mediatek,mt6323-led" },
	{},
	};
	MODULE_DEVICE_TABLE(of, mt6323_led_dt_match);

	static struct platform_driver mt6323_led_driver = {
	.probe = mt6323_led_probe,
	.remove = mt6323_led_remove,
	.driver = {
	.name = "mt6323-led",
	.of_match_table = mt6323_led_dt_match,
	},
	};

	module_platform_driver(mt6323_led_driver);

	MODULE_DESCRIPTION("LED driver for Mediatek MT6323 PMIC");
	MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
	MODULE_LICENSE("GPL");