1 files changed, 80 insertions, 0 deletions
diff --git a/hw/bsp/ch58x/debug_uart.c b/hw/bsp/ch58x/debug_uart.c
new file mode 100644
index 000000000..e63606f33
--- /dev/null
+++ b/hw/bsp/ch58x/debug_uart.c
@@ -0,0 +1,80 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2024 TinyUSB contributors
+ *
+ * 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"
+#include "CH58x_common.h"
+
+//--------------------------------------------------------------------+
+// Ring buffer based UART TX for non-blocking writes
+//--------------------------------------------------------------------+
+
+#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 uart_write(char c) {
+  unsigned int tx_produce_next = (tx_produce + 1) & UART_RINGBUFFER_MASK_TX;
+
+  // If ring buffer is full, wait
+  while (tx_produce_next == tx_consume) {}
+
+  // If UART TX FIFO is empty and no pending data, send directly
+  if ((tx_consume == tx_produce) && (R8_UART1_LSR & RB_LSR_TX_FIFO_EMP)) {
+    R8_UART1_THR = c;
+  } else {
+    tx_buf[tx_produce] = c;
+    tx_produce = tx_produce_next;
+  }
+}
+
+void uart_sync(void) {
+  // Wait for ring buffer to drain
+  while (tx_consume != tx_produce) {
+    if (R8_UART1_LSR & RB_LSR_TX_FIFO_EMP) {
+      R8_UART1_THR = tx_buf[tx_consume];
+      tx_consume = (tx_consume + 1) & UART_RINGBUFFER_MASK_TX;
+    }
+  }
+  // Wait for last byte to finish transmitting
+  while (!(R8_UART1_LSR & RB_LSR_TX_ALL_EMP)) {}
+}
+
+void usart_printf_init(uint32_t baudrate) {
+  tx_produce = 0;
+  tx_consume = 0;
+
+  // Configure UART1 pins: TX=PA9, RX=PA8
+  GPIOA_SetBits(GPIO_Pin_9);
+  GPIOA_ModeCfg(GPIO_Pin_9, GPIO_ModeOut_PP_5mA);
+  GPIOA_ModeCfg(GPIO_Pin_8, GPIO_ModeIN_PU);
+
+  // Init UART1 with specified baud rate
+  UART1_DefInit();
+  UART1_BaudRateCfg(baudrate);
+}