🚸🐛 SW SPI Mode 3 for U8G on STM32 (#27111)

Marlin/src/HAL/STM32/HAL_SPI.cpp

@@ -37,7 +37,7 @@ static SPISettings spiConfig;
 // Public functions
 // ------------------------
 
-#if ENABLED(SOFTWARE_SPI)
+#if ANY(SOFTWARE_SPI, FORCE_SOFT_SPI)
 
   // ------------------------
   // Software SPI

Marlin/src/HAL/STM32/dogm/u8g_com_stm32duino_swspi.cpp

@@ -0,0 +1,136 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2024 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm / Ryan Power
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifdef HAL_STM32
+
+#include "../../../inc/MarlinConfig.h"
+
+#if ALL(HAS_MARLINUI_U8GLIB, FORCE_SOFT_SPI)
+
+#include <U8glib-HAL.h>
+#include "../../shared/HAL_SPI.h"
+
+#define nop asm volatile ("\tnop\n")
+
+static inline uint8_t swSpiTransfer_mode_0(uint8_t b) {
+  for (uint8_t i = 0; i < 8; ++i) {
+    const uint8_t state = (b & 0x80) ? HIGH : LOW;
+    WRITE(DOGLCD_SCK, HIGH);
+    WRITE(DOGLCD_MOSI, state);
+    b <<= 1;
+    WRITE(DOGLCD_SCK, LOW);
+  }
+  return b;
+}
+
+static inline uint8_t swSpiTransfer_mode_3(uint8_t b) {
+  for (uint8_t i = 0; i < 8; ++i) {
+    const uint8_t state = (b & 0x80) ? HIGH : LOW;
+    WRITE(DOGLCD_SCK, LOW);
+    WRITE(DOGLCD_MOSI, state);
+    b <<= 1;
+    WRITE(DOGLCD_SCK, HIGH);
+  }
+  return b;
+}
+
+static void u8g_sw_spi_shift_out(uint8_t val) {
+  #if U8G_SPI_USE_MODE_3
+    swSpiTransfer_mode_3(val);
+  #else
+    swSpiTransfer_mode_0(val);
+  #endif
+}
+
+static void swSpiInit() {
+  #if PIN_EXISTS(LCD_RESET)
+    SET_OUTPUT(LCD_RESET_PIN);
+  #endif
+  SET_OUTPUT(DOGLCD_A0);
+  OUT_WRITE(DOGLCD_SCK, LOW);
+  OUT_WRITE(DOGLCD_MOSI, LOW);
+  OUT_WRITE(DOGLCD_CS, HIGH);
+}
+
+uint8_t u8g_com_HAL_STM32_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr) {
+  switch (msg) {
+    case U8G_COM_MSG_INIT:
+      swSpiInit();
+      break;
+
+    case U8G_COM_MSG_STOP:
+      break;
+
+    case U8G_COM_MSG_RESET:
+      #if PIN_EXISTS(LCD_RESET)
+        WRITE(LCD_RESET_PIN, arg_val);
+      #endif
+      break;
+
+    case U8G_COM_MSG_CHIP_SELECT:
+      #if U8G_SPI_USE_MODE_3        // This LCD SPI is running mode 3 while SD card is running mode 0
+        if (arg_val) {              // SCK idle state needs to be set to the proper idle state before
+                                    //  the next chip select goes active
+          WRITE(DOGLCD_SCK, HIGH);  // Set SCK to mode 3 idle state before CS goes active
+          WRITE(DOGLCD_CS, LOW);
+          nop; // hold SCK high for a few ns
+          nop;
+         }
+        else {
+          WRITE(DOGLCD_CS, HIGH);
+          WRITE(DOGLCD_SCK, LOW);   // Set SCK to mode 0 idle state after CS goes inactive
+        }
+      #else
+        WRITE(DOGLCD_CS, !arg_val);
+      #endif
+      break;
+
+    case U8G_COM_MSG_WRITE_BYTE:
+      u8g_sw_spi_shift_out(arg_val);
+      break;
+
+    case U8G_COM_MSG_WRITE_SEQ: {
+      uint8_t *ptr = (uint8_t *)arg_ptr;
+      while (arg_val > 0) {
+        u8g_sw_spi_shift_out(*ptr++);
+        arg_val--;
+      }
+    } break;
+
+    case U8G_COM_MSG_WRITE_SEQ_P: {
+      uint8_t *ptr = (uint8_t *)arg_ptr;
+      while (arg_val > 0) {
+        u8g_sw_spi_shift_out(u8g_pgm_read(ptr));
+        ptr++;
+        arg_val--;
+      }
+    } break;
+
+    case U8G_COM_MSG_ADDRESS: /* define cmd (arg_val = 0) or data mode (arg_val = 1) */
+      WRITE(DOGLCD_A0, arg_val);
+      break;
+  }
+  return 1;
+}
+
+#endif // HAS_MARLINUI_U8GLIB && FORCE_SOFT_SPI
+#endif // HAL_STM32

Marlin/src/HAL/STM32/u8g/LCD_defines.h

@@ -25,8 +25,8 @@
  * STM32 LCD-specific defines
  */
 
-uint8_t u8g_com_std_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);         // See U8glib-HAL
-uint8_t u8g_com_stm32duino_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);  // See U8glib-HAL
+uint8_t u8g_com_HAL_STM32_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);   // u8g_com_stm32duino_swspi.cpp
+#define U8G_COM_HAL_SW_SPI_FN u8g_com_HAL_STM32_sw_spi_fn
 
-#define U8G_COM_HAL_SW_SPI_FN u8g_com_std_sw_spi_fn
+uint8_t u8g_com_stm32duino_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);  // See U8glib-HAL
 #define U8G_COM_HAL_HW_SPI_FN u8g_com_stm32duino_hw_spi_fn