Add NVS support for relay channel config persistence

- Introduced NVS configuration options in Kconfig.
- Implemented NVS initialization and deinitialization in relay_chn_core.
- Added functions for storing and retrieving relay channel direction and tilt sensitivity in NVS.
- Updated relay_chn_tilt and relay_chn_output to utilize NVS for state management.
- Created relay_chn_nvs.c and relay_chn_nvs.h for NVS-related functionalities.

Closes #1074.

src/relay_chn_nvs.c

@@ -0,0 +1,125 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Kozmotronik Tech
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "esp_check.h"
+#include "relay_chn_nvs.h"
+
+#define RELAY_CHN_KEY_DIR          "dir"
+#ifdef RELAY_CHN_ENABLE_TILTING
+#define RELAY_CHN_KEY_SENS(ch)     "sens_%d"
+#define RELAY_CHN_KEY_TFWD(ch)     "tfwd_%d"
+#define RELAY_CHN_KEY_TREV(ch)     "trev_%d"
+#endif
+
+static const char *TAG = "RELAY_CHN_STORAGE_NVS";
+
+static nvs_handle_t relay_chn_nvs;
+
+esp_err_t relay_chn_nvs_init()
+{
+    esp_err_t ret;
+#if RELAY_CHN_NVS_CUSTOM_PARTITION == 1
+    ret = nvs_open_from_partition(RELAY_CHN_NVS_CUSTOM_PARTITION_NAME,
+                                  RELAY_CHN_NVS_NAMESPACE,
+                                  NVS_READWRITE,
+                                  &relay_chn_nvs);
+
+    ESP_RETURN_ON_ERROR(ret,
+                        TAG,
+                        "Failed to open NVS namespace '%s' from partition '%s' with error %s",
+                        RELAY_CHN_NVS_NAMESPACE,
+                        RELAY_CHN_NVS_CUSTOM_PARTITION_NAME,
+                        esp_err_to_name(ret));
+#else
+    ret = nvs_open(RELAY_CHN_NVS_NAMESPACE, NVS_READWRITE, &relay_chn_nvs);
+    ESP_RETURN_ON_ERROR(ret, TAG, "Failed to open NVS namespace '%s'", RELAY_CHN_NVS_NAMESPACE);
+#endif // RELAY_CHN_NVS_CUSTOM_PARTITION
+    return ESP_OK;
+}
+
+esp_err_t relay_chn_nvs_set_direction(uint8_t ch, relay_chn_direction_t direction)
+{
+    uint8_t direction_val;
+    esp_err_t ret = nvs_get_u8(relay_chn_nvs, RELAY_CHN_KEY_DIR, &direction_val);
+    if (ret == ESP_ERR_NVS_NOT_FOUND) {
+        // The key does not exist yet, set it to zero which is the default direction
+        direction_val = RELAY_CHN_DIRECTION_DEFAULT;
+    } else if (ret != ESP_OK) {
+        ESP_RETURN_ON_ERROR(ret, TAG, "Failed to get direction from NVS with error: %s", esp_err_to_name(ret));
+    }
+    direction_val &= ~(1 << ch); // Clear the bit for the channel
+    direction_val |= (((uint8_t) direction) << ch); // Set the new direction bit
+    ret = nvs_set_u8(relay_chn_nvs, RELAY_CHN_KEY_DIR, direction_val);
+    ESP_RETURN_ON_ERROR(ret, TAG, "Failed to set direction for channel %d", ch);
+    return nvs_commit(relay_chn_nvs);
+}
+
+esp_err_t relay_chn_nvs_get_direction(uint8_t ch, relay_chn_direction_t *direction)
+{
+    ESP_RETURN_ON_FALSE(direction != NULL, ESP_ERR_INVALID_ARG, TAG, "Direction pointer is NULL");
+
+    uint8_t direction_val;
+    esp_err_t ret = nvs_get_u8(relay_chn_nvs, RELAY_CHN_KEY_DIR, &direction_val);
+    if (ret != ESP_OK) {
+        return ret; // Return error if the key does not exist
+    }
+    *direction = (relay_chn_direction_t)((direction_val >> ch) & 0x01);
+    return ESP_OK;
+}
+
+#ifdef RELAY_CHN_ENABLE_TILTING
+esp_err_t relay_chn_nvs_set_tilt_sensitivity(uint8_t ch, uint8_t sensitivity)
+{
+    esp_err_t ret = nvs_set_u8(relay_chn_nvs, RELAY_CHN_KEY_SENS(ch), sensitivity);
+    ESP_RETURN_ON_ERROR(ret, TAG, "Failed to set tilt sensitivity for channel %d", ch);
+    return nvs_commit(relay_chn_nvs);
+}
+
+esp_err_t relay_chn_nvs_get_tilt_sensitivity(uint8_t ch, uint8_t *sensitivity)
+{
+    ESP_RETURN_ON_FALSE(sensitivity != NULL, ESP_ERR_INVALID_ARG, TAG, "Sensitivity pointer is NULL");
+
+    return nvs_get_u8(relay_chn_nvs, RELAY_CHN_KEY_SENS(ch), sensitivity);
+}
+
+esp_err_t relay_chn_nvs_set_tilt_count(uint8_t ch, uint32_t forward_count, uint32_t reverse_count)
+{
+    esp_err_t ret;
+    ret = nvs_set_u32(relay_chn_nvs, RELAY_CHN_KEY_TFWD(ch), forward_count);
+    ESP_RETURN_ON_ERROR(ret, TAG, "Failed to save forward_count tilt counter");
+    ret = nvs_set_u32(relay_chn_nvs, RELAY_CHN_KEY_TREV(ch), reverse_count);
+    ESP_RETURN_ON_ERROR(ret, TAG, "Failed to save reverse_count tilt counter");
+    return nvs_commit(relay_chn_nvs);
+}
+
+esp_err_t relay_chn_nvs_get_tilt_count(uint8_t ch, uint32_t *forward_count, uint32_t *reverse_count)
+{
+    ESP_RETURN_ON_FALSE(forward_count != NULL && reverse_count != NULL,
+                        ESP_ERR_INVALID_ARG, TAG, "Counter pointers are NULL");
+
+    esp_err_t ret = nvs_get_u32(relay_chn_nvs, RELAY_CHN_KEY_TFWD(ch), forward_count);
+    if (ret != ESP_OK) {
+        return ret; // Return error if the key does not exist
+    }
+    return nvs_get_u32(relay_chn_nvs, RELAY_CHN_KEY_TREV(ch), reverse_count);
+}
+#endif // RELAY_CHN_ENABLE_TILTING
+
+esp_err_t relay_chn_nvs_erase_all()
+{
+    // Erase all key-value pairs in the relay_chn NVS namespace
+    esp_err_t ret = nvs_erase_all(relay_chn_nvs);
+    ESP_RETURN_ON_ERROR(ret, TAG, "Failed to erase all keys in NVS namespace '%s'", RELAY_CHN_NVS_NAMESPACE);
+    
+    // Commit the changes
+    return nvs_commit(relay_chn_nvs);
+}
+
+esp_err_t relay_chn_nvs_deinit()
+{
+    nvs_close(relay_chn_nvs);
+    return ESP_OK;
+}