feat: add Kconfig option to allow VDD_SPI_AS_GPIO write (IDFGH-16349)

components/efuse/Kconfig

@@ -70,4 +70,25 @@ menu "eFuse Bit Manager"
         default 128 if EFUSE_CODE_SCHEME_COMPAT_REPEAT
         default 256 if !IDF_TARGET_ESP32
 
+    choice ESP_EFUSE_VDD_SPI_AS_GPIO_DANGEROUS_WRITE
+        bool "[DANGER] Allow Writing to ESP_EFUSE_VDD_SPI_AS_GPIO"
+        default ESP_EFUSE_VDD_SPI_AS_GPIO_DANGEROUS_WRITE_NOT_ALLOWED
+        depends on IDF_TARGET_ESP32C3 || IDF_TARGET_ESP32C6 || IDF_TARGET_ESP32C5 || IDF_TARGET_ESP32C61 || IDF_TARGET_ESP32H2 || IDF_TARGET_ESP32H21
+        help
+            Allows writing to the VDD_SPI_AS_GPIO efuse field.
+
+            WARNING: This is an irreversible operation! Once written, it cannot be undone.
+
+            CRITICAL: If you use Embedded Flash, it will immediately stop working and can never be recovered.
+            This flag changes the VDD_SPI pin to function as a GPIO, which will permanently disable power to the Embedded Flash.
+
+            Ensure that you fully understand the implications of setting this flag.
+
+            If unsure, choice 'Not allowed'.
+        config ESP_EFUSE_VDD_SPI_AS_GPIO_DANGEROUS_WRITE_NOT_ALLOWED
+            bool "Not allowed"
+        config ESP_EFUSE_VDD_SPI_AS_GPIO_DANGEROUS_WRITE_ALLOWED
+            bool "Allowed"
+    endchoice
+
 endmenu

components/efuse/src/esp_efuse_api.c

@@ -145,6 +145,18 @@ esp_err_t esp_efuse_write_field_bit(const esp_efuse_desc_t* field[])
     uint8_t existing = 0;
     const uint8_t one = 1;
 
+    #if defined(ESP_EFUSE_VDD_SPI_AS_GPIO_DANGEROUS_WRITE_NOT_ALLOWED)
+    if (field == ESP_EFUSE_VDD_SPI_AS_GPIO) {
+        ESP_LOGE(TAG, "Writing to VDD_SPI_AS_GPIO is not allowed.");
+        ESP_LOGW(TAG, "[DANGER] Enable CONFIG_ESP_EFUSE_VDD_SPI_AS_GPIO_ALLOWED in menuconfig.");
+        ESP_LOGW(TAG, "WARNING: This is an irreversible operation! Once written, it cannot be undone.");
+        ESP_LOGW(TAG, "CRITICAL: If you use Embedded Flash, it will immediately stop working and can never be recovered.");
+        ESP_LOGW(TAG, "This flag changes the VDD_SPI pin to function as a GPIO, which will permanently disable power to the Embedded Flash.");
+        ESP_LOGW(TAG, "Ensure that you fully understand the implications of setting this flag.");
+        return ESP_ERR_NOT_SUPPORTED;
+    }
+    #endif
+
     if (field == NULL || field[0]->bit_count != 1) {
         return ESP_ERR_INVALID_ARG;
     }