leds: max77705: Add LEDs support

This adds basic support for LEDs for the max77705 PMIC.

Signed-off-by: Dzmitry Sankouski <[e-mail]>
Acked-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

MAINTAINERS

···
 F:	Documentation/devicetree/bindings/*/maxim,max77705*.yaml
 F:	Documentation/devicetree/bindings/*/maxim,max77843.yaml
 F:	Documentation/devicetree/bindings/clock/maxim,max77686.txt
+F:	drivers/leds/leds-max77705.c
 F:	drivers/*/*max77843.c
 F:	drivers/*/max14577*.c
 F:	drivers/*/max77686*.c

drivers/leds/Kconfig

···
 	help
 	  LEDs driver for MAX77650 family of PMICs from Maxim Integrated.
 
+config LEDS_MAX77705
+	tristate "LED support for Maxim MAX77705 PMIC"
+	depends on MFD_MAX77705
+	depends on LEDS_CLASS
+	depends on LEDS_CLASS_MULTICOLOR
+	help
+	  LED driver for MAX77705 PMIC from Maxim Integrated.
+
 config LEDS_MAX8997
 	tristate "LED support for MAX8997 PMIC"
 	depends on LEDS_CLASS && MFD_MAX8997

drivers/leds/Makefile

···
 obj-$(CONFIG_LEDS_LT3593)		+= leds-lt3593.o
 obj-$(CONFIG_LEDS_MAX5970)		+= leds-max5970.o
 obj-$(CONFIG_LEDS_MAX77650)		+= leds-max77650.o
+obj-$(CONFIG_LEDS_MAX77705)		+= leds-max77705.o
 obj-$(CONFIG_LEDS_MAX8997)		+= leds-max8997.o
 obj-$(CONFIG_LEDS_MC13783)		+= leds-mc13783.o
 obj-$(CONFIG_LEDS_MENF21BMC)		+= leds-menf21bmc.o

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 <[e-mail]>
+ */
+
+#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)
+			ret = -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 <[e-mail]>");
+MODULE_LICENSE("GPL");

include/linux/mfd/max77705-private.h

···
 #define MAX77705_SYSTEM_IRQ_SYSOVLO_INT	BIT(5)
 #define MAX77705_SYSTEM_IRQ_TSHDN_INT	BIT(6)
 #define MAX77705_SYSTEM_IRQ_TM_INT	BIT(7)
+/* MAX77705_RGBLED_REG_LEDEN register */
+#define MAX77705_RGBLED_EN_WIDTH	2
+/* MAX77705_RGBLED_REG_LEDBLNK register */
+#define MAX77705_RGB_DELAY_100_STEP_LIM 500
+#define MAX77705_RGB_DELAY_100_STEP_COUNT 4
+#define MAX77705_RGB_DELAY_100_STEP 100
+#define MAX77705_RGB_DELAY_250_STEP_LIM 3250
+#define MAX77705_RGB_DELAY_250_STEP 250
+#define MAX77705_RGB_DELAY_500_STEP 500
+#define MAX77705_RGB_DELAY_500_STEP_COUNT 10
+#define MAX77705_RGB_DELAY_500_STEP_LIM 5000
+#define MAX77705_RGB_DELAY_1000_STEP_LIM 8000
+#define MAX77705_RGB_DELAY_1000_STEP_COUNT 13
+#define MAX77705_RGB_DELAY_1000_STEP 1000
+#define MAX77705_RGB_DELAY_2000_STEP 2000
+#define MAX77705_RGB_DELAY_2000_STEP_COUNT 13
+#define MAX77705_RGB_DELAY_2000_STEP_LIM 12000
 
 enum max77705_hw_rev {
 	MAX77705_PASS1 = 1,