Added some code snippets

snippets/button/code.txt

@@ -0,0 +1,65 @@
+void button_pressed(const struct device *dev, struct gpio_callback *cb,
+		    uint32_t pins)
+{
+	printk("Button pressed at %" PRIu32 "\n", k_cycle_get_32());
+}
+
+int button(void)
+{
+	int ret;
+
+	if (!gpio_is_ready_dt(&button)) {
+		printk("Error: button device %s is not ready\n",
+		       button.port->name);
+		return 0;
+	}
+
+	ret = gpio_pin_configure_dt(&button, GPIO_INPUT);
+	if (ret != 0) {
+		printk("Error %d: failed to configure %s pin %d\n",
+		       ret, button.port->name, button.pin);
+		return 0;
+	}
+
+	ret = gpio_pin_interrupt_configure_dt(&button,
+					      GPIO_INT_EDGE_TO_ACTIVE);
+	if (ret != 0) {
+		printk("Error %d: failed to configure interrupt on %s pin %d\n",
+			ret, button.port->name, button.pin);
+		return 0;
+	}
+
+	gpio_init_callback(&button_cb_data, button_pressed, BIT(button.pin));
+	gpio_add_callback(button.port, &button_cb_data);
+	printk("Set up button at %s pin %d\n", button.port->name, button.pin);
+
+	if (led.port && !device_is_ready(led.port)) {
+		printk("Error %d: LED device %s is not ready; ignoring it\n",
+		       ret, led.port->name);
+		led.port = NULL;
+	}
+	if (led.port) {
+		ret = gpio_pin_configure_dt(&led, GPIO_OUTPUT);
+		if (ret != 0) {
+			printk("Error %d: failed to configure LED device %s pin %d\n",
+			       ret, led.port->name, led.pin);
+			led.port = NULL;
+		} else {
+			printk("Set up LED at %s pin %d\n", led.port->name, led.pin);
+		}
+	}
+
+	printk("Press the button\n");
+	if (led.port) {
+		while (1) {
+			/* If we have an LED, match its state to the button's. */
+			int val = gpio_pin_get_dt(&button);
+
+			if (val >= 0) {
+				gpio_pin_set_dt(&led, val);
+			}
+			k_msleep(SLEEP_TIME_MS);
+		}
+	}
+	return 0;
+}

snippets/button/imports.txt

@@ -0,0 +1,25 @@
+#include <zephyr/device.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/sys/util.h>
+#include <zephyr/sys/printk.h>
+#include <inttypes.h>
+
+#define SLEEP_TIME_MS	1
+
+/*
+ * Get button configuration from the devicetree sw0 alias. This is mandatory.
+ */
+#define SW0_NODE	DT_ALIAS(sw0)
+#if !DT_NODE_HAS_STATUS(SW0_NODE, okay)
+#error "Unsupported board: sw0 devicetree alias is not defined"
+#endif
+static const struct gpio_dt_spec button = GPIO_DT_SPEC_GET_OR(SW0_NODE, gpios,
+							      {0});
+static struct gpio_callback button_cb_data;
+
+/*
+ * The led0 devicetree alias is optional. If present, we'll use it
+ * to turn on the LED whenever the button is pressed.
+ */
+static struct gpio_dt_spec led = GPIO_DT_SPEC_GET_OR(DT_ALIAS(led0), gpios,
+						     {0});

snippets/led/code.txt

@@ -0,0 +1,21 @@
+int blink_led(void) {
+    int ret;
+
+    if (!gpio_is_ready_dt(&led)) {
+        return 0;
+    }
+
+    ret = gpio_pin_configure_dt(&led, GPIO_OUTPUT_ACTIVE);
+    if (ret < 0) {
+        return 0;
+    }
+
+    while (1) {
+        ret = gpio_pin_toggle_dt(&led);
+        if (ret < 0) {
+            return 0;
+        }
+        k_msleep(1000);
+    }
+    return 0;
+}

snippets/led/imports.txt

@@ -0,0 +1,2 @@
+#include <zephyr/drivers/gpio.h>
+#define LED0_NODE DT_ALIAS(led0)