example: refactor deep sleep example to make codes more structured

examples/system/deep_sleep/main/gpio_wakeup.c

@@ -0,0 +1,32 @@
+/*
+ * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+
+#include <stdio.h>
+#include "driver/gpio.h"
+#include "esp_sleep.h"
+#include "sdkconfig.h"
+
+#if CONFIG_EXAMPLE_GPIO_WAKEUP
+#define DEFAULT_WAKEUP_PIN      CONFIG_EXAMPLE_GPIO_WAKEUP_PIN
+#ifdef CONFIG_EXAMPLE_GPIO_WAKEUP_HIGH_LEVEL
+#define DEFAULT_WAKEUP_LEVEL    ESP_GPIO_WAKEUP_GPIO_HIGH
+#else
+#define DEFAULT_WAKEUP_LEVEL    ESP_GPIO_WAKEUP_GPIO_LOW
+#endif
+
+void example_deep_sleep_register_gpio_wakeup(void)
+{
+    const gpio_config_t config = {
+        .pin_bit_mask = BIT(DEFAULT_WAKEUP_PIN),
+        .mode = GPIO_MODE_INPUT,
+    };
+
+    ESP_ERROR_CHECK(gpio_config(&config));
+    ESP_ERROR_CHECK(esp_deep_sleep_enable_gpio_wakeup(BIT(DEFAULT_WAKEUP_PIN), DEFAULT_WAKEUP_LEVEL));
+
+    printf("Enabling GPIO wakeup on pins GPIO%d\n", DEFAULT_WAKEUP_PIN);
+}
+#endif