feat: Support esp32c2 BLE power save example

examples/bluetooth/nimble/power_save/README.md

@@ -16,6 +16,7 @@ This example contains some build configurations. For each configuration, a few c
 - `sdkconfig.40m.esp32c3`: ESP32C3 uses main XTAL as low power clock in light sleep enabled.
 - `sdkconfig.defaults.esp32s3`: ESP32S3 uses 32kHz XTAL as low power clock in light sleep enabled.
 - `sdkconfig.40m.esp32s3`: ESP32S3 uses main XTAL as low power clock in light sleep enabled.
+- `sdkconfig.defaults.esp32c2`: ESP32C2 uses main XTAL as low power clock in light sleep enabled.
 ## How to use example
 
 ### Hardware Required
@@ -48,6 +49,15 @@ idf.py menuconfig
 7. Enable power up main XTAL during light sleep:
    - `Component config > Bluetooth > Controller Options > MODEM SLEEP Options > [*] power up main XTAL during light sleep`
 
+#### For Chip ESP32-C2
+
+4. Enable bluetooth modem sleep:
+   - `Component config > Bluetooth > Controller Options`
+     - `[*] Enable BLE sleep`
+5. Power down flash during light sleep:
+   - `Component config > Hardware Settings > Sleep Config`
+     - `[*] Power down flash in light sleep when there is no SPIRAM`
+
 ### Build and Flash
 
 ```
@@ -107,8 +117,10 @@ I (463) NimBLE:
 | ESP32   | 231 mA      | 14.1 mA      | X                      | 1.9 mA                  |
 | ESP32C3 | 262 mA      | 12 mA        | 2.3 mA                 | 140 uA                  |
 | ESP32S3 | 240 mA      | 17.9 mA      | 3.3 mA                 | 230 uA                  |
+| ESP32C2 | 130 mA      | 18.0 mA      | 2.5 mA                 | X                       |
 X: This feature is currently not supported.
 
 ## Example Breakdown
 
-- ESP32 does not support the use of main XTAL in light sleep mode, so an external 32kHz crystal is required.
+- ESP32 does not support the use of main XTAL in light sleep mode, so an external 32kHz crystal is required.
+- ESP32C2 does not support the use of 32KHz XTAL in light sleep mode, the XTAL frequency is set to 26MHz in default.

examples/bluetooth/nimble/power_save/main/Kconfig.projbuild

@@ -2,7 +2,8 @@ menu "Example Configuration"
 
     choice EXAMPLE_MAX_CPU_FREQ
         prompt "Maximum CPU frequency"
-        default EXAMPLE_MAX_CPU_FREQ_160
+        default EXAMPLE_MAX_CPU_FREQ_160 if !IDF_TARGET_ESP32C2
+        default EXAMPLE_MAX_CPU_FREQ_120 if IDF_TARGET_ESP32C2
         depends on PM_ENABLE
         help
             Maximum CPU frequency to use for dynamic frequency scaling.
@@ -11,6 +12,9 @@ menu "Example Configuration"
             bool "80 MHz"
         config EXAMPLE_MAX_CPU_FREQ_160
             bool "160 MHz"
+        config EXAMPLE_MAX_CPU_FREQ_120
+            bool "120 MHz"
+            depends on IDF_TARGET_ESP32C2
         config EXAMPLE_MAX_CPU_FREQ_240
             bool "240 MHz"
             depends on IDF_TARGET_ESP32 || IDF_TARGET_ESP32S3
@@ -19,12 +23,14 @@ menu "Example Configuration"
     config EXAMPLE_MAX_CPU_FREQ_MHZ
         int
         default 80 if EXAMPLE_MAX_CPU_FREQ_80
+        default 120 if EXAMPLE_MAX_CPU_FREQ_120
         default 160 if EXAMPLE_MAX_CPU_FREQ_160
         default 240 if EXAMPLE_MAX_CPU_FREQ_240
 
     choice EXAMPLE_MIN_CPU_FREQ
         prompt "Minimum CPU frequency"
-        default EXAMPLE_MIN_CPU_FREQ_40M
+        default EXAMPLE_MIN_CPU_FREQ_40M if !IDF_TARGET_ESP32C2
+        default EXAMPLE_MIN_CPU_FREQ_26M if IDF_TARGET_ESP32C2
         depends on PM_ENABLE
         help
             Minimum CPU frequency to use for dynamic frequency scaling.
@@ -42,6 +48,10 @@ menu "Example Configuration"
         config EXAMPLE_MIN_CPU_FREQ_40M
             bool "40 MHz (use with 40MHz XTAL)"
             depends on XTAL_FREQ_40 || XTAL_FREQ_AUTO
+        config EXAMPLE_MIN_CPU_FREQ_26M
+            bool "26 MHz (use with 26MHz XTAL)"
+            depends on IDF_TARGET_ESP32C2
+            depends on XTAL_FREQ_26 || XTAL_FREQ_AUTO
         config EXAMPLE_MIN_CPU_FREQ_20M
             bool "20 MHz (use with 40MHz XTAL)"
             depends on XTAL_FREQ_40 || XTAL_FREQ_AUTO
@@ -54,6 +64,7 @@ menu "Example Configuration"
         int
         default 80 if EXAMPLE_MIN_CPU_FREQ_80M
         default 40 if EXAMPLE_MIN_CPU_FREQ_40M
+        default 26 if EXAMPLE_MIN_CPU_FREQ_26M
         default 20 if EXAMPLE_MIN_CPU_FREQ_20M
         default 10 if EXAMPLE_MIN_CPU_FREQ_10M
 

examples/bluetooth/nimble/power_save/main/main.c

@@ -524,6 +524,8 @@ app_main(void)
     esp_pm_config_esp32c3_t pm_config = {
 #elif CONFIG_IDF_TARGET_ESP32S3
     esp_pm_config_esp32s3_t pm_config = {
+#elif CONFIG_IDF_TARGET_ESP32C2
+    esp_pm_config_esp32c2_t pm_config = {
 #endif
             .max_freq_mhz = CONFIG_EXAMPLE_MAX_CPU_FREQ_MHZ,
             .min_freq_mhz = CONFIG_EXAMPLE_MIN_CPU_FREQ_MHZ,

examples/bluetooth/nimble/power_save/sdkconfig.defaults.esp32c2

@@ -0,0 +1,19 @@
+CONFIG_IDF_TARGET="esp32h2"
+
+# Bluetooth Low Power Config
+CONFIG_BT_LE_SLEEP_ENABLE=y
+
+#
+# Power Management
+#
+CONFIG_PM_ENABLE=y
+CONFIG_PM_DFS_INIT_AUTO=y
+
+# XTAL Freq Config
+CONFIG_XTAL_FREQ_26=y
+CONFIG_XTAL_FREQ=26
+
+#
+# Sleep Config
+#
+CONFIG_ESP_SLEEP_POWER_DOWN_FLASH=y