drivers: blink: blink-gpio-led: add initial implementation

Add a blink driver implementation for a GPIO-controlled LED.

Signed-off-by: Gerard Marull-Paretas <[email protected]>

Author: gmarull

drivers/blink/CMakeLists.txt

@@ -2,3 +2,4 @@
 # SPDX-License-Identifier: Apache-2.0
 
 zephyr_library()
+zephyr_library_sources_ifdef(CONFIG_BLINK_GPIO_LED gpio_led.c)

drivers/blink/Kconfig

@@ -18,4 +18,6 @@ module = BLINK
 module-str = blink
 source "subsys/logging/Kconfig.template.log_config"
 
+rsource "Kconfig.gpio_led"
+
 endif # BLINK

drivers/blink/Kconfig.gpio_led

@@ -0,0 +1,11 @@
+# Copyright (c) 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+config BLINK_GPIO_LED
+	bool "GPIO-controlled LED blink driver"
+	default y
+	depends on DT_HAS_BLINK_GPIO_LED_ENABLED
+	select GPIO
+	help
+	  Enable this option to use the GPIO-controlled LED blink driver. This
+	  demonstrates how to implement a driver for a custom driver class.

drivers/blink/gpio_led.c

@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor ASA
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT blink_gpio_led
+
+#include <zephyr/device.h>
+
+#include <zephyr/devicetree.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+
+#include <app/drivers/blink.h>
+
+LOG_MODULE_REGISTER(blink_gpio_led, CONFIG_BLINK_LOG_LEVEL);
+
+struct blink_gpio_led_data {
+	struct k_timer timer;
+};
+
+struct blink_gpio_led_config {
+	struct gpio_dt_spec led;
+	unsigned int period_ms;
+};
+
+static void blink_gpio_led_on_timer_expire(struct k_timer *timer)
+{
+	const struct device *dev = k_timer_user_data_get(timer);
+	const struct blink_gpio_led_config *config = dev->config;
+	int ret;
+
+	ret = gpio_pin_toggle_dt(&config->led);
+	if (ret < 0) {
+		LOG_ERR("Could not toggle LED GPIO (%d)", ret);
+	}
+}
+
+static int blink_gpio_led_set_period_ms(const struct device *dev,
+					unsigned int period_ms)
+{
+	const struct blink_gpio_led_config *config = dev->config;
+	struct blink_gpio_led_data *data = dev->data;
+
+	if (period_ms == 0) {
+		k_timer_stop(&data->timer);
+		return gpio_pin_set_dt(&config->led, 0);
+	}
+
+	k_timer_start(&data->timer, K_MSEC(period_ms), K_MSEC(period_ms));
+
+	return 0;
+}
+
+static const struct blink_driver_api blink_gpio_led_api = {
+	.set_period_ms = &blink_gpio_led_set_period_ms,
+};
+
+static int blink_gpio_led_init(const struct device *dev)
+{
+	const struct blink_gpio_led_config *config = dev->config;
+	struct blink_gpio_led_data *data = dev->data;
+	int ret;
+
+	if (!gpio_is_ready_dt(&config->led)) {
+		LOG_ERR("LED GPIO not ready");
+		return -ENODEV;
+	}
+
+	ret = gpio_pin_configure_dt(&config->led, GPIO_OUTPUT_INACTIVE);
+	if (ret < 0) {
+		LOG_ERR("Could not configure LED GPIO (%d)", ret);
+		return ret;
+	}
+
+	k_timer_init(&data->timer, blink_gpio_led_on_timer_expire, NULL);
+	k_timer_user_data_set(&data->timer, (void *)dev);
+
+	if (config->period_ms > 0) {
+		k_timer_start(&data->timer, K_MSEC(config->period_ms),
+			      K_MSEC(config->period_ms));
+	}
+
+	return 0;
+}
+
+#define BLINK_GPIO_LED_DEFINE(inst)                                            \
+	static struct blink_gpio_led_data data##inst;                          \
+                                                                               \
+	static const struct blink_gpio_led_config config##inst = {             \
+	    .led = GPIO_DT_SPEC_INST_GET(inst, led_gpios),                     \
+	    .period_ms = DT_INST_PROP_OR(inst, blink_period_ms, 0U),           \
+	};                                                                     \
+                                                                               \
+	DEVICE_DT_INST_DEFINE(inst, blink_gpio_led_init, NULL, &data##inst,    \
+			      &config##inst, POST_KERNEL,                      \
+			      CONFIG_BLINK_INIT_PRIORITY,                      \
+			      &blink_gpio_led_api);
+
+DT_INST_FOREACH_STATUS_OKAY(BLINK_GPIO_LED_DEFINE)

dts/bindings/blink/blink-gpio-leds.yaml

@@ -0,0 +1,28 @@
+# Copyright (c) 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+  A generic binding for a GPIO-controlled blinking LED. Note that this binding
+  has no vendor prefix, as it does not target a specific device or vendor.
+
+  Example definition in devicetree:
+
+    blink-gpio-led {
+        compatible = "blink-gpio-led";
+        led-gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>;
+        blink-period-ms = <1000>;
+    };
+
+compatible: "blink-gpio-led"
+
+include: base.yaml
+
+properties:
+  led-gpios:
+    type: phandle-array
+    required: true
+    description: GPIO-controlled LED.
+
+  blink-period-ms:
+    type: int
+    description: Initial blinking period in milliseconds.