1 files changed, 105 insertions, 0 deletions
diff --git a/hw/bsp/ch32f20x/debug_uart.c b/hw/bsp/ch32f20x/debug_uart.c
new file mode 100644
index 000000000..a595eb6f7
--- /dev/null
+++ b/hw/bsp/ch32f20x/debug_uart.c
@@ -0,0 +1,105 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2023 Denis Krasutski
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+#include <ch32f20x.h>
+
+#include "board.h"
+#include "debug_uart.h"
+
+#define UART_RINGBUFFER_SIZE_TX 64
+#define UART_RINGBUFFER_MASK_TX (UART_RINGBUFFER_SIZE_TX-1)
+
+static char tx_buf[UART_RINGBUFFER_SIZE_TX];
+static unsigned int tx_produce = 0;
+static volatile unsigned int tx_consume = 0;
+
+void UART_DEV_IRQHandler(void)
+{
+  if(USART_GetITStatus(UART_DEV, USART_IT_TC) != RESET) {
+    USART_ClearITPendingBit(UART_DEV, USART_IT_TC);
+
+    if(tx_consume != tx_produce) {
+      USART_SendData(UART_DEV, tx_buf[tx_consume]);
+      tx_consume = (tx_consume + 1) & UART_RINGBUFFER_MASK_TX;
+    }
+  }
+}
+
+void uart_write(char c)
+{
+  unsigned int tx_produce_next = (tx_produce + 1) & UART_RINGBUFFER_MASK_TX;
+
+  NVIC_DisableIRQ(UART_DEV_IRQn);
+  if((tx_consume != tx_produce) || (USART_GetFlagStatus(UART_DEV, USART_FLAG_TXE) == RESET)) {
+    tx_buf[tx_produce] = c;
+    tx_produce = tx_produce_next;
+  } else {
+    USART_SendData(UART_DEV, c);
+  }
+  NVIC_EnableIRQ(UART_DEV_IRQn);
+}
+
+void uart_sync(void)
+{
+  while(tx_consume != tx_produce) {
+    //Waiting for transfer complete
+  }
+}
+
+void usart_printf_init(uint32_t baudrate)
+{
+  tx_produce = 0;
+  tx_consume = 0;
+
+  UART_DEV_CLK_EN();
+
+  GPIO_InitTypeDef gpio_config = {
+    .GPIO_Pin = UART_DEV_TX_PIN,
+    .GPIO_Speed = GPIO_Speed_50MHz,
+    .GPIO_Mode = GPIO_Mode_AF_PP,
+  };
+  GPIO_Init(UART_DEV_GPIO_PORT, &gpio_config);
+
+  USART_InitTypeDef uart_config = {
+    .USART_BaudRate = baudrate,
+    .USART_WordLength = USART_WordLength_8b,
+    .USART_StopBits = USART_StopBits_1,
+    .USART_Parity = USART_Parity_No,
+    .USART_HardwareFlowControl = USART_HardwareFlowControl_None,
+    .USART_Mode = USART_Mode_Tx,
+  };
+
+  USART_Init(UART_DEV, &uart_config);
+  USART_ITConfig(UART_DEV, USART_IT_TC, ENABLE);
+  USART_Cmd(UART_DEV, ENABLE);
+
+  NVIC_InitTypeDef nvic_config = {
+    .NVIC_IRQChannel = UART_DEV_IRQn,
+    .NVIC_IRQChannelPreemptionPriority = 1,
+    .NVIC_IRQChannelSubPriority = 3,
+    .NVIC_IRQChannelCmd = ENABLE,
+  };
+  NVIC_Init(&nvic_config);
+}