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Commit 216ec6cc authored by Sean Wang's avatar Sean Wang Committed by Jacek Anaszewski
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leds: Add LED support for MT6323 PMIC 



MT6323 PMIC is a multi-function device that includes LED function.
It allows attaching up to 4 LEDs which can either be on, off or dimmed
and/or blinked with the controller.

Signed-off-by: default avatarSean Wang <sean.wang@mediatek.com>
Signed-off-by: default avatarJacek Anaszewski <jacek.anaszewski@gmail.com>
parent 7ea79ae8

drivers/leds/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -126,6 +126,14 @@ config LEDS_MIKROTIK_RB532 
	  This option enables support for the so called "User LED" of

	  Mikrotik's Routerboard 532.



config LEDS_MT6323

	tristate "LED Support for Mediatek MT6323 PMIC"

	depends on LEDS_CLASS

	depends on MFD_MT6397

	help

	  This option enables support for on-chip LED drivers found on

	  Mediatek MT6323 PMIC.



config LEDS_S3C24XX

	tristate "LED Support for Samsung S3C24XX GPIO LEDs"

	depends on LEDS_CLASS

drivers/leds/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -71,6 +71,7 @@ obj-$(CONFIG_LEDS_IS31FL32XX) += leds-is31fl32xx.o 
obj-$(CONFIG_LEDS_PM8058)		+= leds-pm8058.o

obj-$(CONFIG_LEDS_MLXCPLD)		+= leds-mlxcpld.o

obj-$(CONFIG_LEDS_NIC78BX)		+= leds-nic78bx.o

obj-$(CONFIG_LEDS_MT6323)		+= leds-mt6323.o



# LED SPI Drivers

obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o

drivers/leds/leds-mt6323.c

0 → 100644
+502 −0
Original line number Diff line number Diff line 
/*

 * 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 < 0 || 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");