Add support for multi-color LEDs

drivers/led/CMakeLists.txt

@@ -9,6 +9,7 @@ zephyr_library_sources_ifdef(CONFIG_HT16K33 ht16k33.c)
 zephyr_library_sources_ifdef(CONFIG_IS31FL3194 is31fl3194.c)
 zephyr_library_sources_ifdef(CONFIG_IS31FL3216A is31fl3216a.c)
 zephyr_library_sources_ifdef(CONFIG_IS31FL3733 is31fl3733.c)
+zephyr_library_sources_ifdef(CONFIG_LEDS_GROUP_MULTICOLOR leds_group_multicolor.c)
 zephyr_library_sources_ifdef(CONFIG_LED_AXP192_AXP2101 led_axp192.c)
 zephyr_library_sources_ifdef(CONFIG_LED_DAC led_dac.c)
 zephyr_library_sources_ifdef(CONFIG_LED_GPIO led_gpio.c)

drivers/led/Kconfig

@@ -34,6 +34,7 @@ source "drivers/led/Kconfig.ht16k33"
 source "drivers/led/Kconfig.is31fl3194"
 source "drivers/led/Kconfig.is31fl3216a"
 source "drivers/led/Kconfig.is31fl3733"
+source "drivers/led/Kconfig.leds-group-multicolor"
 source "drivers/led/Kconfig.lp3943"
 source "drivers/led/Kconfig.lp50xx"
 source "drivers/led/Kconfig.lp5562"

drivers/led/Kconfig.leds-group-multicolor

@@ -0,0 +1,12 @@
+# Copyright (c) 2025 Seagate Technology LLC
+# SPDX-License-Identifier: Apache-2.0
+
+config LEDS_GROUP_MULTICOLOR
+	bool "LEDs group multi-color driver"
+	default y
+	depends on DT_HAS_LEDS_GROUP_MULTICOLOR_ENABLED
+	help
+	  Enable this driver to supports multi-color LEDs built with several
+	  monochromatic LEDs.
+
+	  See the leds-group-multicolor DT binding for details.

drivers/led/Kconfig.pwm

@@ -4,6 +4,7 @@
 config LED_PWM
 	bool "PWM LED driver"
 	default y
-	depends on PWM && DT_HAS_PWM_LEDS_ENABLED
+	depends on DT_HAS_PWM_LEDS_ENABLED
+	select PWM
 	help
 	  Enable driver for PWM LEDs.

drivers/led/leds_group_multicolor.c

@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2025 Seagate Technology LLC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT leds_group_multicolor
+
+/**
+ * @file
+ * @brief Driver for multi-color LED built from monochromatic LEDs.
+ */
+
+#include <zephyr/drivers/led.h>
+#include <zephyr/device.h>
+#include <zephyr/kernel.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(leds_group_multicolor, CONFIG_LED_LOG_LEVEL);
+
+struct leds_group_multicolor_config {
+	uint8_t num_leds;
+	const struct led_dt_spec *led;
+};
+
+static int leds_group_multicolor_set_color(const struct device *dev, uint32_t led,
+					   uint8_t num_colors, const uint8_t *color)
+{
+	const struct leds_group_multicolor_config *config = dev->config;
+
+	if (led != 0) {
+		return -EINVAL;
+	}
+	if (num_colors != config->num_leds) {
+		return -EINVAL;
+	}
+
+	for (uint8_t i = 0; i < num_colors; i++) {
+		int err;
+
+		err = led_set_brightness_dt(&config->led[i], color[i]);
+		if (err) {
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+static int leds_group_multicolor_init(const struct device *dev)
+{
+	const struct leds_group_multicolor_config *config = dev->config;
+
+	for (uint8_t i = 0; i < config->num_leds; i++) {
+		const struct led_dt_spec *led = &config->led[i];
+
+		if (!led_is_ready_dt(led)) {
+			LOG_ERR("%s: LED device %s is not ready", dev->name, led->dev->name);
+			return -ENODEV;
+		}
+	}
+
+	return 0;
+}
+
+static DEVICE_API(led, leds_group_multicolor_api) = {
+	.set_color = leds_group_multicolor_set_color,
+};
+
+#define LED_DT_SPEC_GET_BY_PHANDLE_IDX(node_id, prop, idx)			\
+	LED_DT_SPEC_GET(DT_PHANDLE_BY_IDX(node_id, prop, idx))
+
+#define LEDS_GROUP_MULTICOLOR_DEVICE(inst)					\
+										\
+	BUILD_ASSERT(DT_INST_PROP_LEN(inst, leds) > 0,				\
+			"at least one LED phandle must be present");		\
+										\
+	static const struct led_dt_spec led_group_multicolor_##inst[] = {	\
+		DT_INST_FOREACH_PROP_ELEM_SEP(					\
+			inst, leds, LED_DT_SPEC_GET_BY_PHANDLE_IDX, (,))	\
+	};									\
+										\
+	static const struct leds_group_multicolor_config			\
+				leds_group_multicolor_config_##inst = {		\
+		.num_leds	= ARRAY_SIZE(led_group_multicolor_##inst),	\
+		.led		= led_group_multicolor_##inst,			\
+	};									\
+										\
+	DEVICE_DT_INST_DEFINE(inst, &leds_group_multicolor_init, NULL,		\
+			      NULL, &leds_group_multicolor_config_##inst,	\
+			      POST_KERNEL, CONFIG_LED_INIT_PRIORITY,		\
+			      &leds_group_multicolor_api);
+
+DT_INST_FOREACH_STATUS_OKAY(LEDS_GROUP_MULTICOLOR_DEVICE)

dts/bindings/led/gpio-leds.yaml

@@ -36,13 +36,13 @@ compatible: "gpio-leds"
 
 child-binding:
   description: GPIO LED child node
+
+  include:
+    - name: led-node.yaml
+      property-allowlist:
+        - label
+
   properties:
     gpios:
       type: phandle-array
       required: true
-    label:
-      type: string
-      description: |
-        Human readable string describing the LED. It can be used by an
-        application to identify this LED or to retrieve its number/index
-        (i.e. child node number) on the parent device.

dts/bindings/led/led-controller.yaml

@@ -5,10 +5,10 @@
 
 child-binding:
   description: LED child node
+
+  include: led-node.yaml
+
   properties:
-    label:
-      type: string
-      description: Human readable string describing the LED
     index:
       type: int
       description: |
@@ -17,16 +17,3 @@ child-binding:
         controller. For example, this allows to handle boards where the
         LEDs in an array/strip are not wired following the LED order of
         the controller.
-    color-mapping:
-      type: array
-      description: |
-        Channel to color mapping of a multicolor LED. If a LED supports
-        several colors, then the color-mapping property can be used to
-        describe how the hardware channels and the colors are mapped.
-
-        For example the channel to color mapping of RGB LEDs would be
-
-           color-mapping =
-                <LED_COLOR_ID_RED>,
-                <LED_COLOR_ID_GREEN>,
-                <LED_COLOR_ID_BLUE>;

dts/bindings/led/led-node.yaml

@@ -0,0 +1,25 @@
+# Copyright (c) 2025 Seagate Technology LLC
+# SPDX-License-Identifier: Apache-2.0
+
+# Common fields for LED nodes
+
+properties:
+  label:
+    type: string
+    description: |
+      Human readable string describing the LED. It can be used by an
+      application to identify this LED or to retrieve its number/index
+      (i.e. child node number) on the parent device.
+  color-mapping:
+    type: array
+    description: |
+      Channel to color mapping of a multicolor LED. If a LED supports
+      several colors, then the color-mapping property can be used to
+      describe how the hardware channels and the colors are mapped.
+
+      For example the channel to color mapping of RGB LEDs would be
+
+         color-mapping =
+              <LED_COLOR_ID_RED>,
+              <LED_COLOR_ID_GREEN>,
+              <LED_COLOR_ID_BLUE>;

dts/bindings/led/leds-group-multicolor.yaml

@@ -0,0 +1,49 @@
+# Copyright (c) 2025 Seagate Technology LLC
+# SPDX-License-Identifier: Apache-2.0
+
+title: Combines several monochromatic LEDs into one multi-color LED.
+
+description: |
+  Here is an example that defines an RGB LED with a group of monochromatic
+  PWM LEDs. Note that the pwms property definition handle depends on the PWM
+  controller model. In this example, an STM32 PWM controller is assumed.
+
+  #include <zephyr/dt-bindings/led/led.h>
+
+  / {
+          monochromatic-leds {
+                  compatible = "pwm-leds";
+
+                  red_pwm_led: led-0 {
+                          pwms = <&pwm1 1 PWM_MSEC(20) PWM_POLARITY_NORMAL>;
+                  };
+
+                  green_pwm_led: led-1 {
+                          pwms = <&pwm2 1 PWM_MSEC(20) PWM_POLARITY_NORMAL>;
+                  };
+
+                  blue_pwm_led: led-2 {
+                          pwms = <&pwm3 1 PWM_MSEC(20) PWM_POLARITY_NORMAL>;
+                  };
+          };
+
+          rgb-led {
+                  compatible = "leds-group-multicolor";
+
+                  leds = <&red_pwm_led>, <&green_pwm_led>, <&blue_pwm_led>;
+                  color-mapping = <LED_COLOR_ID_RED>,
+                                  <LED_COLOR_ID_GREEN>,
+                                  <LED_COLOR_ID_BLUE>;
+          };
+  };
+
+compatible: "leds-group-multicolor"
+
+include: led-node.yaml
+
+properties:
+  leds:
+    required: true
+    type: phandles
+    description: |
+      References to monochromatic LED nodes.

dts/bindings/led/pwm-leds.yaml

@@ -10,6 +10,12 @@ compatible: "pwm-leds"
 
 child-binding:
   description: PWM LED child node
+
+  include:
+    - name: led-node.yaml
+      property-allowlist:
+        - label
+
   properties:
     pwms:
       required: true
@@ -22,10 +28,3 @@ child-binding:
         brigtness granularity) and lesser than 50 milliseconds (average visual
         persistence time of the human eye). Typical values for the PWM period
         are 10 or 20 milliseconds.
-
-    label:
-      type: string
-      description: |
-        Human readable string describing the LED. It can be used by an
-        application to identify this LED or to retrieve its number/index
-        (i.e. child node number) on the parent device.

samples/drivers/led/pwm/prj.conf

@@ -1,7 +1,5 @@
 CONFIG_LOG=y
 
-CONFIG_PWM=y
-
 CONFIG_LED=y
 
 CONFIG_LOG_MODE_IMMEDIATE=y

tests/drivers/build_all/led/app.overlay

@@ -207,6 +207,14 @@
 			test_pwm_led0: test_pwm_led_0 {
 				pwms = <&test_pwm 0 0 0>;
 			};
+			test_pwm_led1: test_pwm_led_1 {
+				pwms = <&test_pwm 1 0 0>;
+			};
+		};
+
+		multi-led {
+			compatible = "leds-group-multicolor";
+			leds = <&test_pwm_led0>, <&test_pwm_led1>;
 		};
 	};
 };

tests/drivers/build_all/led/prj.conf

@@ -1,4 +1,3 @@
 CONFIG_TEST=y
 CONFIG_TEST_USERSPACE=y
 CONFIG_LED=y
-CONFIG_PWM=y