Fix SPI communication with overclocked Pico W

lib/rp2040/platform_def.txt

@@ -1,5 +1,6 @@
 -DPICO_CYW43_ARCH_THREADSAFE_BACKGROUND=1
 -DCYW43_LWIP=1
+-DCYW43_PIO_CLOCK_DIV_DYNAMIC=1
 -DCFG_TUSB_MCU=OPT_MCU_RP2040
 -DARM_MATH_CM0_FAMILY
 -DARM_MATH_CM0_PLUS

tools/libpico/CMakeLists.txt

@@ -52,6 +52,7 @@ if (${cpu} MATCHES "rp2040")
         PICO_RP2040_B2_SUPPORTED=1
         PICO_CYW43_ARCH_THREADSAFE_BACKGROUND=1
         CYW43_WARN=//
+        CYW43_PIO_CLOCK_DIV_DYNAMIC=1
         PICO_XOSC_STARTUP_DELAY_MULTIPLIER=64
         PICO_FLOAT_SUPPORT_ROM_V1=1
         PICO_DOUBLE_SUPPORT_ROM_V1=1

tools/platformio-build.py

@@ -363,6 +363,7 @@ def configure_network_flags(cpp_defines):
     env.Append(CPPDEFINES=[
         ("PICO_CYW43_ARCH_THREADSAFE_BACKGROUND", 1),
         ("CYW43_LWIP", 1),
+        ("CYW43_PIO_CLOCK_DIV_DYNAMIC", 1),
         ("LWIP_IPV4", 1),
         ("LWIP_IGMP", 1),
         ("LWIP_CHECKSUM_CTRL_PER_NETIF", 1)

variants/rpipicow/picow_init.cpp

@@ -19,7 +19,9 @@
 */
 
 #include <pico/cyw43_arch.h>
+#include <pico/cyw43_driver.h>
 #include <pico/lwip_nosys.h>
+#include "hardware/clocks.h"
 #include "hardware/resets.h"
 #include "hardware/gpio.h"
 #include "hardware/adc.h"
@@ -62,6 +64,11 @@ bool __isPicoW = true;
 extern "C" void initVariant() {
     __isPicoW = CheckPicoW();
     if (__isPicoW) {
+        // Fix for overclocked CPU: SPI communication breaks down with default "div by 2" speed
+        // So, divide clock by 4 for anything including and above 250MHz CPU frequency.
+        if (clock_get_hz(clk_sys) >= 250000000) {
+            cyw43_set_pio_clock_divisor(4, 0); // div by 4.0
+        }
         cyw43_arch_init_with_country(WIFICC);
     }
 }