Add support for CPU Frequency switching

Experimental!

Author: me-no-dev

cores/esp32/esp32-hal-misc.c

@@ -25,6 +25,7 @@
 #include"esp_bt.h"
 #endif//CONFIG_BT_ENABLED
 #include<sys/time.h>
+#include"soc/rtc.h"
 #include"esp32-hal.h"
 
 //Undocumented!!! Get chip temperature in Farenheit
@@ -41,19 +42,41 @@ void yield()
 vPortYield();
 }
 
+staticuint32_t_cpu_freq_mhz=240;
+
+boolcpuFrequencySet(uint32_tcpu_freq_mhz){
+if(_cpu_freq_mhz==cpu_freq_mhz){
+return true;
+ }
+rtc_cpu_freq_config_tconf;
+if(!rtc_clk_cpu_freq_mhz_to_config(cpu_freq_mhz, &conf)){
+log_e("CPU clock could not be set to %u MHz", cpu_freq_mhz);
+return false;
+ }
+rtc_clk_cpu_freq_set_config(&conf);
+_cpu_freq_mhz=conf.freq_mhz;
+return true;
+}
+
+uint32_tcpuFrequencyGet(){
+rtc_cpu_freq_config_tconf;
+rtc_clk_cpu_freq_get_config(&conf);
+returnconf.freq_mhz;
+}
+
 unsigned long IRAM_ATTRmicros()
 {
-return (unsigned long) esp_timer_get_time();
+return (unsigned long) (esp_timer_get_time() * (240 / _cpu_freq_mhz));
 }
 
 unsigned long IRAM_ATTRmillis()
 {
-return (unsigned long) (esp_timer_get_time() / 1000);
+return (unsigned long) (micros() / 1000);
 }
 
 voiddelay(uint32_tms)
 {
-vTaskDelay(ms / portTICK_PERIOD_MS);
+vTaskDelay(ms / portTICK_PERIOD_MS / (240 / _cpu_freq_mhz));
 }
 
 voidIRAM_ATTRdelayMicroseconds(uint32_tus)

cores/esp32/esp32-hal.h

@@ -72,6 +72,9 @@ void yield(void);
 //returns chip temperature in Celsius
 floattemperatureRead();
 
+boolcpuFrequencySet(uint32_tcpu_freq_mhz);
+uint32_tcpuFrequencyGet();
+
 unsigned longmicros();
 unsigned longmillis();
 voiddelay(uint32_t);