1 files changed, 119 insertions, 0 deletions
diff --git a/hw/bsp/ch32v30x/debug_uart.c b/hw/bsp/ch32v30x/debug_uart.c
new file mode 100644
index 000000000..2fd3a9d64
--- /dev/null
+++ b/hw/bsp/ch32v30x/debug_uart.c
@@ -0,0 +1,119 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Greg Davill
+ *
+ * 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 "debug_uart.h"
+
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wstrict-prototypes"
+#endif
+
+#include <ch32v30x.h>
+
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
+
+#define UART_RINGBUFFER_SIZE_TX 128
+#define UART_RINGBUFFER_MASK_TX (UART_RINGBUFFER_SIZE_TX-1)
+
+static char tx_buf[UART_RINGBUFFER_SIZE_TX];
+static unsigned int tx_produce;
+static volatile unsigned int tx_consume;
+
+void USART1_IRQHandler(void) __attribute__((naked));
+void USART1_IRQHandler(void) {
+      __asm volatile ("call USART1_IRQHandler_impl; mret");
+}
+
+__attribute__((used)) void USART1_IRQHandler_impl(void)
+{
+	if(USART_GetITStatus(USART1, USART_IT_TC) != RESET)
+    {
+        USART_ClearITPendingBit(USART1, USART_IT_TC);
+
+		if(tx_consume != tx_produce) {
+			USART_SendData(USART1, 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(USART1_IRQn);
+    if((tx_consume != tx_produce) || (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET)) {
+		tx_buf[tx_produce] = c;
+		tx_produce = tx_produce_next;
+	} else {
+		USART_SendData(USART1, c);
+	}
+    NVIC_EnableIRQ(USART1_IRQn);
+}
+
+
+void uart_sync(void)
+{
+	while(tx_consume != tx_produce);
+}
+
+
+void usart_printf_init(uint32_t baudrate)
+{
+  GPIO_InitTypeDef GPIO_InitStructure;
+  USART_InitTypeDef USART_InitStructure;
+
+  tx_produce = 0;
+  tx_consume = 0;
+
+  RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 | RCC_APB2Periph_GPIOA, ENABLE);
+
+  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
+  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
+  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
+  GPIO_Init(GPIOA, &GPIO_InitStructure);
+
+  USART_InitStructure.USART_BaudRate = baudrate;
+  USART_InitStructure.USART_WordLength = USART_WordLength_8b;
+  USART_InitStructure.USART_StopBits = USART_StopBits_1;
+  USART_InitStructure.USART_Parity = USART_Parity_No;
+  USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
+  USART_InitStructure.USART_Mode = USART_Mode_Tx;
+
+  USART_Init(USART1, &USART_InitStructure);
+  USART_ITConfig(USART1, USART_IT_TC, ENABLE);
+  USART_Cmd(USART1, ENABLE);
+
+  NVIC_InitTypeDef NVIC_InitStructure = { 0 };
+  NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
+  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
+  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;
+  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
+  NVIC_Init(&NVIC_InitStructure);
+}