drivers/leds/leds-max77705.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Based on leds-max77650 driver
 *
 * LED driver for MAXIM 77705 PMIC.
 * Copyright (C) 2025 Dzmitry Sankouski <dsankouski@gmail.org>
 */

#include <linux/i2c.h>
#include <linux/led-class-multicolor.h>
#include <linux/leds.h>
#include <linux/mfd/max77705-private.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#define MAX77705_LED_NUM_LEDS			4
#define MAX77705_LED_EN_MASK			GENMASK(1, 0)
#define MAX77705_LED_MAX_BRIGHTNESS		0xff
#define MAX77705_LED_EN_SHIFT(reg)		(reg * MAX77705_RGBLED_EN_WIDTH)
#define MAX77705_LED_REG_BRIGHTNESS(reg)	(reg + MAX77705_RGBLED_REG_LED0BRT)

struct max77705_led {
	struct led_classdev cdev;
	struct led_classdev_mc mcdev;
	struct regmap *regmap;

	struct mc_subled *subled_info;
};

static const struct regmap_config max77705_leds_regmap_config = {
	.reg_base = MAX77705_RGBLED_REG_BASE,
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = MAX77705_LED_REG_END,
};

static int max77705_rgb_blink(struct led_classdev *cdev,
				unsigned long *delay_on,
				unsigned long *delay_off)
{
	struct max77705_led *led = container_of(cdev, struct max77705_led, cdev);
	int value, on_value, off_value;

	if (*delay_on < MAX77705_RGB_DELAY_100_STEP)
		on_value = 0;
	else if (*delay_on < MAX77705_RGB_DELAY_100_STEP_LIM)
		on_value = *delay_on / MAX77705_RGB_DELAY_100_STEP - 1;
	else if (*delay_on < MAX77705_RGB_DELAY_250_STEP_LIM)
		on_value = (*delay_on - MAX77705_RGB_DELAY_100_STEP_LIM) /
				MAX77705_RGB_DELAY_250_STEP +
				MAX77705_RGB_DELAY_100_STEP_COUNT;
	else
		on_value = 15;

	on_value <<= 4;

	if (*delay_off < 1)
		off_value = 0;
	else if (*delay_off < MAX77705_RGB_DELAY_500_STEP)
		off_value = 1;
	else if (*delay_off < MAX77705_RGB_DELAY_500_STEP_LIM)
		off_value = *delay_off / MAX77705_RGB_DELAY_500_STEP;
	else if (*delay_off < MAX77705_RGB_DELAY_1000_STEP_LIM)
		off_value = (*delay_off - MAX77705_RGB_DELAY_1000_STEP_LIM) /
				MAX77705_RGB_DELAY_1000_STEP +
				MAX77705_RGB_DELAY_500_STEP_COUNT;
	else if (*delay_off < MAX77705_RGB_DELAY_2000_STEP_LIM)
		off_value = (*delay_off - MAX77705_RGB_DELAY_2000_STEP_LIM) /
				MAX77705_RGB_DELAY_2000_STEP +
				MAX77705_RGB_DELAY_1000_STEP_COUNT;
	else
		off_value = 15;

	value = on_value | off_value;
	return regmap_write(led->regmap, MAX77705_RGBLED_REG_LEDBLNK, value);
}

static int max77705_led_brightness_set(struct regmap *regmap, struct mc_subled *subled,
				int num_colors)
{
	int ret;

	for (int i = 0; i < num_colors; i++) {
		unsigned int channel, brightness;

		channel = subled[i].channel;
		brightness = subled[i].brightness;

		if (brightness == LED_OFF) {
			/* Flash OFF */
			ret = regmap_update_bits(regmap,
					MAX77705_RGBLED_REG_LEDEN,
					MAX77705_LED_EN_MASK << MAX77705_LED_EN_SHIFT(channel), 0);
		} else {
			/* Set current */
			ret = regmap_write(regmap, MAX77705_LED_REG_BRIGHTNESS(channel),
					brightness);
			if (ret < 0)
				return ret;

			ret = regmap_update_bits(regmap,
					MAX77705_RGBLED_REG_LEDEN,
					LED_ON << MAX77705_LED_EN_SHIFT(channel),
					MAX77705_LED_EN_MASK << MAX77705_LED_EN_SHIFT(channel));
		}
	}

	return ret;
}

static int max77705_led_brightness_set_single(struct led_classdev *cdev,
					enum led_brightness brightness)
{
	struct max77705_led *led = container_of(cdev, struct max77705_led, cdev);

	led->subled_info->brightness = brightness;

	return max77705_led_brightness_set(led->regmap, led->subled_info, 1);
}

static int max77705_led_brightness_set_multi(struct led_classdev *cdev,
					enum led_brightness brightness)
{
	struct led_classdev_mc *mcdev = lcdev_to_mccdev(cdev);
	struct max77705_led *led = container_of(mcdev, struct max77705_led, mcdev);

	led_mc_calc_color_components(mcdev, brightness);

	return max77705_led_brightness_set(led->regmap, led->mcdev.subled_info, mcdev->num_colors);
}

static int max77705_parse_subled(struct device *dev, struct fwnode_handle *np,
				struct mc_subled *info)
{
	u32 color = LED_COLOR_ID_GREEN;
	u32 reg;
	int ret;

	ret = fwnode_property_read_u32(np, "reg", &reg);
	if (ret || !reg || reg >= MAX77705_LED_NUM_LEDS)
		return dev_err_probe(dev, -EINVAL, "invalid \"reg\" of %pOFn\n", np);

	info->channel = reg;

	ret = fwnode_property_read_u32(np, "color", &color);
	if (ret < 0 && ret != -EINVAL)
		return dev_err_probe(dev, ret,
				     "failed to parse \"color\" of %pOF\n", np);

	info->color_index = color;

	return 0;
}

static int max77705_add_led(struct device *dev, struct regmap *regmap, struct fwnode_handle *np)
{
	int ret, i = 0;
	unsigned int color, reg;
	struct max77705_led *led;
	struct led_classdev *cdev;
	struct mc_subled *info;
	struct fwnode_handle *child;
	struct led_init_data init_data = {};

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

	ret = fwnode_property_read_u32(np, "color", &color);
	if (ret < 0 && ret != -EINVAL)
		return dev_err_probe(dev, ret,
			      "failed to parse \"color\" of %pOF\n", np);

	led->regmap = regmap;
	init_data.fwnode = np;

	if (color == LED_COLOR_ID_RGB) {
		int num_channels = of_get_available_child_count(to_of_node(np));

		ret = fwnode_property_read_u32(np, "reg", &reg);
		if (ret || reg >= MAX77705_LED_NUM_LEDS)
			return -EINVAL;

		info = devm_kcalloc(dev, num_channels, sizeof(*info), GFP_KERNEL);
		if (!info)
			return -ENOMEM;

		cdev = &led->mcdev.led_cdev;
		cdev->max_brightness = MAX77705_LED_MAX_BRIGHTNESS;
		cdev->brightness_set_blocking = max77705_led_brightness_set_multi;
		cdev->blink_set = max77705_rgb_blink;

		fwnode_for_each_available_child_node(np, child) {
			ret = max77705_parse_subled(dev, child, &info[i]);
			if (ret < 0)
				return ret;

			info[i].intensity = 0;
			i++;
		}

		led->mcdev.subled_info = info;
		led->mcdev.num_colors = num_channels;
		led->cdev = *cdev;

		ret = devm_led_classdev_multicolor_register_ext(dev, &led->mcdev, &init_data);
		if (ret)
			return ret;

		ret = max77705_led_brightness_set_multi(&led->cdev, LED_OFF);
		if (ret)
			return ret;
	} else {
		info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
		if (!info)
			return -ENOMEM;

		max77705_parse_subled(dev, np, info);

		led->subled_info = info;
		led->cdev.brightness_set_blocking = max77705_led_brightness_set_single;
		led->cdev.blink_set = max77705_rgb_blink;
		led->cdev.max_brightness = MAX77705_LED_MAX_BRIGHTNESS;

		ret = devm_led_classdev_register_ext(dev, &led->cdev, &init_data);
		if (ret)
			return ret;

		ret = max77705_led_brightness_set_single(&led->cdev, LED_OFF);
		if (ret)
			return ret;
	}

	return 0;
}

static int max77705_led_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct i2c_client *i2c = to_i2c_client(pdev->dev.parent);
	struct regmap *regmap;
	int ret;

	regmap = devm_regmap_init_i2c(i2c, &max77705_leds_regmap_config);
	if (IS_ERR(regmap))
		return dev_err_probe(dev, PTR_ERR(regmap), "Failed to register LEDs regmap\n");

	device_for_each_child_node_scoped(dev, child) {
		ret = max77705_add_led(dev, regmap, child);
		if (ret)
			return ret;
	}

	return 0;
}

static const struct of_device_id max77705_led_of_match[] = {
	{ .compatible = "maxim,max77705-rgb" },
	{ }
};
MODULE_DEVICE_TABLE(of, max77705_led_of_match);

static struct platform_driver max77705_led_driver = {
	.driver = {
		.name = "max77705-led",
		.of_match_table = max77705_led_of_match,
	},
	.probe = max77705_led_probe,
};
module_platform_driver(max77705_led_driver);

MODULE_DESCRIPTION("Maxim MAX77705 LED driver");
MODULE_AUTHOR("Dzmitry Sankouski <dsankouski@gmail.com>");
MODULE_LICENSE("GPL");