Merge pull request #7430 from Lanzaa/rp2040_cpu_frequency

Add frequency setting for RP2040 boards.

Author: tannewt

ports/mimxrt10xx/common-hal/microcontroller/Processor.c

@@ -58,15 +58,14 @@ float common_hal_mcu_processor_get_temperature(void) {
     #endif
 }
 
-uint32_t common_hal_mcu_processor_set_frequency(mcu_processor_obj_t *self,
+void common_hal_mcu_processor_set_frequency(mcu_processor_obj_t *self,
     uint32_t frequency) {
     uint32_t freq = frequency / 1000000;
     if (freq != 24 && freq != 150 && freq != 396 && freq != 450 && freq != 528 && freq != 600 &&
         freq != 720 && freq != 816 && freq != 912 && freq != 960 && freq != 1008) {
         mp_raise_ValueError(translate("Frequency must be 24, 150, 396, 450, 528, 600, 720, 816, 912, 960 or 1008 Mhz"));
     }
     SystemCoreClock = setarmclock(frequency);
-    return SystemCoreClock;
 }
 
 

ports/raspberrypi/common-hal/microcontroller/Processor.c

@@ -28,12 +28,16 @@
 #include <string.h>
 
 #include "py/mphal.h"
+#include "py/runtime.h"
 #include "common-hal/microcontroller/Processor.h"
 #include "shared-bindings/microcontroller/Processor.h"
 #include "shared-bindings/microcontroller/ResetReason.h"
+#include "shared-bindings/time/__init__.h"
 
+#include "pico/stdlib.h"
 #include "src/rp2_common/hardware_adc/include/hardware/adc.h"
 #include "src/rp2_common/hardware_clocks/include/hardware/clocks.h"
+#include "src/rp2_common/hardware_vreg/include/hardware/vreg.h"
 #include "src/rp2_common/hardware_watchdog/include/hardware/watchdog.h"
 
 #include "src/rp2040/hardware_regs/include/hardware/regs/vreg_and_chip_reset.h"
@@ -60,6 +64,27 @@ uint32_t common_hal_mcu_processor_get_frequency(void) {
     return clock_get_hz(clk_sys);
 }
 
+void common_hal_mcu_processor_set_frequency(mcu_processor_obj_t *self, uint32_t frequency) {
+    uint vco, postdiv1, postdiv2;
+    uint32_t freq_khz = frequency / 1000;
+    if (!check_sys_clock_khz(freq_khz, &vco, &postdiv1, &postdiv2)) {
+        mp_arg_error_invalid(MP_QSTR_frequency);
+    }
+    // These voltages are approximate based on the PicoDVI examples.
+    enum vreg_voltage voltage = VREG_VOLTAGE_1_10;
+    if (freq_khz >= 400000) {
+        voltage = VREG_VOLTAGE_1_30;
+    } else if (freq_khz >= 300000) {
+        voltage = VREG_VOLTAGE_1_20;
+    } else if (freq_khz > 133000) {
+        voltage = VREG_VOLTAGE_1_20;
+    }
+    vreg_set_voltage(voltage);
+    // Wait for a stable voltage
+    common_hal_time_delay_ms(10);
+    set_sys_clock_khz(freq_khz, false);
+}
+
 void common_hal_mcu_processor_get_uid(uint8_t raw_id[]) {
     pico_unique_board_id_t retrieved_id;
     pico_get_unique_board_id(&retrieved_id);

ports/raspberrypi/mpconfigport.mk

@@ -49,3 +49,4 @@ CIRCUITPY_BUILD_EXTENSIONS ?= uf2
 USB_NUM_ENDPOINT_PAIRS = 8
 
 INTERNAL_FLASH_FILESYSTEM = 1
+CIRCUITPY_SETTABLE_PROCESSOR_FREQUENCY = 1

shared-bindings/microcontroller/Processor.c

@@ -67,8 +67,15 @@
 //|     frequency: int
 //|     """The CPU operating frequency in Hertz.
 //|
-//|     **Limitations:** Setting the ``frequency`` is possible only on some i.MX boards.
-//|     On most boards, ``frequency`` is read-only.
+//|     **Limitations:** On most boards, ``frequency`` is read-only. Setting
+//|     the ``frequency`` is possible on RP2040 boards and some i.MX boards.
+//|
+//|     .. warning:: Overclocking likely voids your warranties and may reduce
+//|       the lifetime of the chip.
+//|
+//|     .. warning:: Changing the frequency may cause issues with other
+//|       subsystems, such as USB, PWM, and PIO. To minimize issues, set the CPU
+//|       frequency before initializing other systems.
 //|     """
 
 #if CIRCUITPY_SETTABLE_PROCESSOR_FREQUENCY

shared-bindings/microcontroller/Processor.h

@@ -39,6 +39,6 @@ mcu_reset_reason_t common_hal_mcu_processor_get_reset_reason(void);
 float common_hal_mcu_processor_get_temperature(void);
 void common_hal_mcu_processor_get_uid(uint8_t raw_id[]);
 float common_hal_mcu_processor_get_voltage(void);
-uint32_t common_hal_mcu_processor_set_frequency(mcu_processor_obj_t *self, uint32_t frequency);
+void common_hal_mcu_processor_set_frequency(mcu_processor_obj_t *self, uint32_t frequency);
 
 #endif  // MICROPY_INCLUDED_SHARED_BINDINGS_MICROCONTROLLER_PROCESSOR_H