1 files changed, 64 insertions, 0 deletions
diff --git a/src/io.c b/src/io.c
new file mode 100644
index 0000000..0da33d1
--- /dev/null
+++ b/src/io.c
@@ -0,0 +1,64 @@
+#include <stdint.h>
+#include <stdio.h>
+
+#include "ch573/gpio.h"
+#include "ch573/uart.h"
+
+#include "io.h"
+
+#ifndef DEBUG_UART
+#define DEBUG_UART UART1
+#endif
+
+#define UART1 ch573_uart__uart1
+#define UART CH573_UART__UART_T_INTF
+
+#define GPIO_PORT_A ch573_gpio__gpio_port_a
+#define GPIO_PORT CH573_GPIO__GPIO_PORT_T_INTF
+
+#define gpio_usart1_tx_pin 9
+
+static int uart1_FILE_put(char ch, FILE* unused)
+{
+  if (ch == '\n') {
+    uart1_FILE_put('\r', unused);
+  }
+
+  while (!UART.lsr.thr_empty.get(UART1));
+  UART.thr.set(UART1, ch);
+
+  return 1;
+}
+
+static int uart1_FILE_get(FILE* f)
+{
+  return -1;
+}
+
+static int uart1_FILE_flush(FILE* f)
+{
+  return 0;
+}
+
+FILE _uart1_FILE = (FILE){
+    .put = uart1_FILE_put,
+    .get = uart1_FILE_get,
+    .flush = uart1_FILE_flush,
+    .flags = __SWR,
+};
+
+FILE* const stdout = &_uart1_FILE;
+
+void init_uart1_for_stdout(void)
+{
+  GPIO_PORT.dir.set(GPIO_PORT_A, DIR_OUT, gpio_usart1_tx_pin);
+  GPIO_PORT.pd_drv.set(GPIO_PORT_A, 0, gpio_usart1_tx_pin);
+
+  UART.div.set(UART1, 1);
+  UART.fcr.set(UART1, 0x07);
+  UART.ier.txd_en.set(UART1, ON);
+  UART.lcr.word_sz.set(UART1, WORD_SZ_8_BITS);
+
+  volatile uint32_t dl = (10 * 6400000 / 8 / BAUD_RATE + 5) / 10;
+  UART.dl.set(UART1, dl);
+}