kconfig: make 120 MSPI DDR as experimental feature

Kconfig

@@ -522,3 +522,12 @@ mainmenu "Espressif IoT Development Framework Configuration"
     menu "Component config"
         source "$COMPONENT_KCONFIGS_SOURCE_FILE"
     endmenu
+
+    config IDF_EXPERIMENTAL_FEATURES
+        bool "Make experimental features visible"
+        default "n"
+        help
+            By enabling this option, ESP-IDF experimental feature options will be visible.
+
+            Note you should still enable a certain experimental feature option to use it, and you
+            should read the corresponding risk warning and known issue list carefully.

components/esp_psram/esp32s3/Kconfig.spiram

@@ -82,7 +82,20 @@ menu "SPI RAM config"
             Select the speed for the SPI RAM chip.
 
         config SPIRAM_SPEED_120M
+            depends on SPIRAM_MODE_QUAD || IDF_EXPERIMENTAL_FEATURES
             bool "120MHz clock speed"
+
+            help
+                - Quad PSRAM 120 MHz is stable.
+
+                - Octal PSRAM 120 MHz is an experimental feature, it works when
+                  the temperature is stable.
+
+                    Risks:
+                        If your chip powers on at a certain temperature, then after the temperature
+                        increases or decreases by approximately 20 Celsius degrees (depending on the
+                        chip), the accesses to / from PSRAM will crash randomly.
+
         config SPIRAM_SPEED_80M
             bool "80MHz clock speed"
         config SPIRAM_SPEED_40M
@@ -96,5 +109,4 @@ menu "SPI RAM config"
         default 40 if SPIRAM_SPEED_40M
 
     source "$IDF_PATH/components/esp_psram/Kconfig.spiram.common"    # insert non-chip-specific items here
-
 endmenu

components/esptool_py/Kconfig.projbuild

@@ -95,7 +95,18 @@ menu "Serial flasher config"
         config ESPTOOLPY_FLASHFREQ_120M
             bool "120 MHz"
             select SPI_FLASH_HPM_ENABLE
-            depends on SOC_MEMSPI_SRC_FREQ_120M
+            depends on SOC_MEMSPI_SRC_FREQ_120M && \
+                (ESPTOOLPY_FLASH_SAMPLE_MODE_STR || IDF_EXPERIMENTAL_FEATURES)
+            help
+                - Flash 120 MHz SDR mode is stable.
+                - Flash 120 MHz DDR mode is an experimental feature, it works when
+                  the temperature is stable.
+
+                    Risks:
+                        If your chip powers on at a certain temperature, then after the temperature
+                        increases or decreases by approximately 20 Celsius degrees (depending on the
+                        chip), the program will crash randomly.
+
         config ESPTOOLPY_FLASHFREQ_80M
             bool "80 MHz"
             depends on SOC_MEMSPI_SRC_FREQ_80M_SUPPORTED

components/spi_flash/Kconfig

@@ -310,5 +310,4 @@ menu "SPI Flash driver"
         help
             This option is invisible, and will be selected automatically
             when ``ESPTOOLPY_FLASHFREQ_120M`` is selected.
-
 endmenu