Chitu V5 with extra GPIO init (#18299)

Co-authored-by: Scott Lahteine <github@thinkyhead.com>

Marlin/src/pins/pins.h

@@ -541,7 +541,7 @@
 #elif MB(CCROBOT_MEEB_3DP)
   #include "stm32f1/pins_CCROBOT_MEEB_3DP.h"    // STM32F1                                env:STM32F103RC_meeb
 #elif MB(CHITU3D_V5)
-  #include "stm32f1/pins_CHITU3D_V5.h"          // STM32F1                                env:chitu_f103
+  #include "stm32f1/pins_CHITU3D_V5.h"          // STM32F1                                env:chitu_f103 env:chitu_v5_gpio_init
 #elif MB(CHITU3D_V6)
   #include "stm32f1/pins_CHITU3D_V6.h"          // STM32F1                                env:chitu_f103
 

buildroot/share/PlatformIO/variants/CHITU_F103/wirish/boards_setup.cpp

@@ -84,32 +84,38 @@ namespace wirish {
             rcc_set_prescaler(RCC_PRESCALER_APB1, RCC_APB1_HCLK_DIV_2);
             rcc_set_prescaler(RCC_PRESCALER_APB2, RCC_APB2_HCLK_DIV_1);
             rcc_clk_disable(RCC_USB);
-      #if F_CPU == 72000000
+#if F_CPU == 72000000
             rcc_set_prescaler(RCC_PRESCALER_USB, RCC_USB_SYSCLK_DIV_1_5);
-      #elif F_CPU == 48000000
+#elif F_CPU == 48000000
             rcc_set_prescaler(RCC_PRESCALER_USB, RCC_USB_SYSCLK_DIV_1);
-      #endif
+#endif
         }
 
         __weak void board_setup_gpio(void) {
+            /**
+             * PA14 is a pull up pin. But, some V5 boards it start with LOW state! And just behave properly when the Z- PROBE is actived at least once.
+             * So, if the sensor isnt actived, the PA14 pin will be forever in LOW state, telling Marlin the probe IS ALWAYS ACTIVE, that isnt the case!
+             * Chitu original firmware seems to start with every pullup PIN with HIGH to workaround this.
+             * So we are doing the same here.
+             * This hack only works if applied *before* the GPIO Init, it's the reason I did it here.
+             */
+            #ifdef CHITU_V5_Z_MIN_BUGFIX
+              GPIOA->regs->BSRR = (1U << PA14);
+            #endif
             gpio_init_all();
         }
 
         __weak void board_setup_usb(void) {
-
-
-
 #ifdef SERIAL_USB
 #ifdef GENERIC_BOOTLOADER
-      //Reset the USB interface on generic boards - developed by Victor PV
+          // Reset the USB interface on generic boards - developed by Victor PV
           gpio_set_mode(PIN_MAP[PA12].gpio_device, PIN_MAP[PA12].gpio_bit, GPIO_OUTPUT_PP);
           gpio_write_bit(PIN_MAP[PA12].gpio_device, PIN_MAP[PA12].gpio_bit,0);
 
-      for(volatile unsigned int i=0;i<512;i++);// Only small delay seems to be needed, and USB pins will get configured in Serial.begin
+          for (volatile unsigned int i = 0; i < 512; i++); // Only small delay seems to be needed, and USB pins will get configured in Serial.begin
           gpio_set_mode(PIN_MAP[PA12].gpio_device, PIN_MAP[PA12].gpio_bit, GPIO_INPUT_FLOATING);
 #endif
-
-      Serial.begin();// Roger Clark. Changed SerialUSB to Serial for Arduino sketch compatibility
+          Serial.begin(); // Roger Clark. Changed SerialUSB to Serial for Arduino sketch compatibility
 #endif
         }
 
@@ -118,6 +124,5 @@ namespace wirish {
             // interrupts work out of the box.
             afio_init();
         }
-
     }
 }

platformio.ini

@@ -664,6 +664,15 @@ build_flags   = ${common_stm32f1.build_flags}
 build_unflags = ${common_stm32f1.build_unflags}
   -DCONFIG_MAPLE_MINI_NO_DISABLE_DEBUG= -DERROR_LED_PORT=GPIOE -DERROR_LED_PIN=6
 
+#
+# Some Chitu V5 boards have a problem with GPIO init.
+# Use this target if G28 or G29 are always failing.
+#
+[env:chitu_v5_gpio_init]
+platform      = ${common_stm32f1.platform}
+extends       = env:chitu_f103
+build_flags   = ${env:chitu_f103.build_flags} -DCHITU_V5_Z_MIN_BUGFIX
+
 #
 # STM32F401VE
 # 'STEVAL-3DP001V1' STM32F401VE board - https://www.st.com/en/evaluation-tools/steval-3dp001v1.html