Add leds_gpio driver and modify blinky application

drivers/led/CMakeLists.txt

@@ -1,3 +1,4 @@
+zephyr_sources_ifdef(CONFIG_LED_GPIO leds_gpio.c)
 zephyr_sources_ifdef(CONFIG_LP3943 lp3943.c)
 zephyr_sources_ifdef(CONFIG_LP5562 lp5562.c)
 zephyr_sources_ifdef(CONFIG_PCA9633 pca9633.c)

drivers/led/Kconfig

@@ -23,6 +23,7 @@ config LED_INIT_PRIORITY
 	help
 	  System initialization priority for LED drivers.
 
+source "drivers/led/Kconfig.gpio"
 source "drivers/led/Kconfig.lp3943"
 source "drivers/led/Kconfig.lp5562"
 source "drivers/led/Kconfig.pca9633"

drivers/led/Kconfig.gpio

@@ -0,0 +1,27 @@
+#
+# Copyright (c) 2018 Manivannan Sadhasivam
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+config LED_GPIO
+	bool "LED GPIO driver"
+	depends on GPIO
+	help
+	  Enable software driven LED using GPIO pin.
+
+# ---------- LED 0 ----------
+
+config LED_GPIO_0
+	bool "Enable LED GPIO 0"
+	depends on LED_GPIO
+	help
+	  Enable LED GPIO 0.
+
+# ---------- LED 1 ----------
+
+config LED_GPIO_1
+	bool "Enable LED GPIO 1"
+	depends on LED_GPIO
+	help
+	  Enable LED GPIO 1.

drivers/led/Kconfig.lp3943

@@ -14,7 +14,7 @@ menuconfig LP3943
 	  states at a specified rate. Each channel can drive up to 25 mA
 	  per LED.
 
-if !HAS_DTS_I2C
+if I2C && !HAS_DTS_I2C
 
 config LP3943_DEV_NAME
 	string "LP3943 device name"

drivers/led/leds_gpio.c

@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2018 Manivannan Sadhasivam
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file
+ * @brief LEDs driver for GPIOs
+ *
+ * This driver controls LED devices attached to GPIO pins which
+ * are declared under leds node in board devicetree. The driver
+ * takes care of configuring the pin to output state before using it.
+ *
+ * TODO: Implement Software Blinking
+ */
+
+#include <device.h>
+#include <gpio.h>
+#include <led.h>
+#include <misc/util.h>
+#include <zephyr.h>
+
+#define SYS_LOG_LEVEL CONFIG_SYS_LOG_LED_LEVEL
+#include <logging/sys_log.h>
+
+#include "led_context.h"
+
+enum led_gpio_modes {
+	LED_OFF,
+	LED_ON,
+};
+
+struct led_gpio_cfg {
+	char *gpio_port;
+	u8_t gpio_pin;
+	u8_t gpio_polarity;
+};
+
+struct led_gpio_data {
+	struct device *gpio;
+	struct led_data dev_data;
+};
+
+static inline int led_gpio_on(struct device *dev, u32_t led)
+{
+	const struct led_gpio_cfg *cfg = dev->config->config_info;
+	struct led_gpio_data *data = dev->driver_data;
+
+	/* Make sure that the LED is valid */
+	if (led != cfg->gpio_pin) {
+		return -EINVAL;
+	}
+
+	/*
+	 * Check for active high or active low defined in DT. For
+	 * simplicity, non zero cases are considered as active high
+	 * and zeroes are active low.
+	 */
+	gpio_pin_write(data->gpio, led,
+		       (cfg->gpio_polarity & GPIO_INT_ACTIVE_HIGH) != 0);
+
+	return 0;
+}
+
+static inline int led_gpio_off(struct device *dev, u32_t led)
+{
+	const struct led_gpio_cfg *cfg = dev->config->config_info;
+	struct led_gpio_data *data = dev->driver_data;
+
+	/* Make sure that the LED is valid */
+	if (led != cfg->gpio_pin) {
+		return -EINVAL;
+	}
+
+	/*
+	 * Check for active high or active low defined in DT. For
+	 * simplicity, non zero cases are considered as active high
+	 * and zeroes are active low.
+	 */
+	gpio_pin_write(data->gpio, led,
+		       (cfg->gpio_polarity & GPIO_INT_ACTIVE_HIGH) == 0);
+
+	return 0;
+}
+
+static int led_gpio_init(struct device *dev)
+{
+	const struct led_gpio_cfg *cfg = dev->config->config_info;
+	struct led_gpio_data *data = dev->driver_data;
+	struct led_data *dev_data = &data->dev_data;
+
+	data->gpio = device_get_binding(cfg->gpio_port);
+	if (!data->gpio) {
+		SYS_LOG_DBG("Failed to get GPIO device");
+		return -EINVAL;
+	}
+
+	/* Set LED pin as output */
+	gpio_pin_configure(data->gpio, cfg->gpio_pin, GPIO_DIR_OUT);
+
+	/* Blinking and Brightness are not supported yet */
+	dev_data->min_period = 0;
+	dev_data->max_period = 0;
+	dev_data->min_brightness = 0;
+	dev_data->max_brightness = 0;
+
+	return 0;
+}
+
+static const struct led_driver_api led_gpio_api = {
+	.on = led_gpio_on,
+	.off = led_gpio_off,
+};
+
+#define	DEFINE_LED_GPIO(_num)						\
+									\
+static struct led_gpio_data led_gpio_data_##_num;			\
+									\
+static const struct led_gpio_cfg led_gpio_cfg_##_num = {		\
+	.gpio_port	= LED##_num##_GPIO_CONTROLLER,			\
+	.gpio_pin	= LED##_num##_GPIO_PIN,				\
+	.gpio_polarity	= LED##_num##_GPIO_FLAGS,			\
+};									\
+									\
+DEVICE_AND_API_INIT(led_gpio_##_num, LED##_num##_LABEL,			\
+	    led_gpio_init,						\
+	    &led_gpio_data_##_num,					\
+	    &led_gpio_cfg_##_num,					\
+	    POST_KERNEL, CONFIG_LED_INIT_PRIORITY,			\
+	    &led_gpio_api)
+
+#ifdef CONFIG_LED_GPIO_0
+DEFINE_LED_GPIO(0);
+#endif
+
+#ifdef CONFIG_LED_GPIO_1
+DEFINE_LED_GPIO(1);
+#endif

samples/basic/blinky/README.rst

@@ -6,9 +6,8 @@ Blinky Application
 Overview
 ********
 
-The Blinky example shows how to configure GPIO pins as outputs which can also be
-used to drive LEDs on the hardware usually delivered as "User LEDs" on many of
-the supported boards in Zephyr.
+The Blinky example shows how to drive LEDs on the hardware usually
+delivered as "User LEDs" on many of the supported boards in Zephyr.
 
 Requirements
 ************

samples/basic/blinky/prj.conf

@@ -1,2 +1,5 @@
 CONFIG_GPIO=y
 CONFIG_SERIAL=n
+CONFIG_LED=y
+CONFIG_LED_GPIO=y
+CONFIG_LED_GPIO_0=y

samples/basic/blinky/src/main.c

@@ -6,27 +6,26 @@
 
 #include <zephyr.h>
 #include <device.h>
-#include <gpio.h>
+#include <led.h>
 
-#define LED_PORT LED0_GPIO_CONTROLLER
-#define LED	LED0_GPIO_PIN
+#define LED_DEV_NAME	LED0_LABEL
+#define LED		LED0_GPIO_PIN
 
 /* 1000 msec = 1 sec */
 #define SLEEP_TIME 	1000
 
 void main(void)
 {
-	int cnt = 0;
 	struct device *dev;
 
-	dev = device_get_binding(LED_PORT);
-	/* Set LED pin as output */
-	gpio_pin_configure(dev, LED, GPIO_DIR_OUT);
+	dev = device_get_binding(LED_DEV_NAME);
 
 	while (1) {
 		/* Set pin to HIGH/LOW every 1 second */
-		gpio_pin_write(dev, LED, cnt % 2);
-		cnt++;
+		led_on(dev, LED);
+		k_sleep(SLEEP_TIME);
+
+		led_off(dev, LED);
 		k_sleep(SLEEP_TIME);
 	}
 }