RP2040 PWM driver now supports pre-scaler

Author: Richard Unger

src/drivers/hardware_specific/rp2040/rp2040_mcu.cpp

@@ -9,10 +9,11 @@
 #include "../../hardware_api.h"
 #include "./rp2040_mcu.h"
 #include "hardware/pwm.h"
+#include "hardware/clocks.h"
 
 #define _PWM_FREQUENCY 24000
 #define _PWM_FREQUENCY_MAX 66000
-#define _PWM_FREQUENCY_MIN 5000
+#define _PWM_FREQUENCY_MIN 1
 
 
 
@@ -30,12 +31,12 @@ void setupPWM(int pin, long pwm_frequency, bool invert, RP2040DriverParams* para
 	params->pins[index] = pin;
 	params->slice[index] = slice;
 	params->chan[index] = chan;
-	uint32_t sysclock_hz = machine.freq();
+	uint32_t sysclock_hz = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_CLK_SYS) * 1000;
 	uint32_t factor = 4096 * 2 * pwm_frequency;
 	uint32_t div = sysclock_hz / factor;
 	if (sysclock_hz % factor !=0) div+=1;
 	if (div < 16) div = 16;
-	uint32_t wrapvalue = sysclock_hz *16 / div / pwm_frequency - 1;
+	uint32_t wrapvalue = (sysclock_hz * 8) / div / pwm_frequency - 1;
 #ifdef SIMPLEFOC_DEBUG_RP2040
 	SimpleFOCDebug::print("Configuring pin ");
 	SimpleFOCDebug::print(pin);
@@ -50,7 +51,7 @@ void setupPWM(int pin, long pwm_frequency, bool invert, RP2040DriverParams* para
 	SimpleFOCDebug::print(".");
 	SimpleFOCDebug::print((int)(div&0xF));
 	SimpleFOCDebug::print(" top value ");
-	SimpleFOCDebug::println(wrapvalue);
+	SimpleFOCDebug::println((int)wrapvalue);
 #endif
 	if (wrapvalue < 999)
 		SimpleFOCDebug::println("Warning: PWM resolution is low.");