You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
38 lines
719 B
38 lines
719 B
#include "uart.h"
|
|
#include "fdt.h"
|
|
|
|
volatile uint32_t* uart;
|
|
|
|
void uart_putchar(uint8_t ch)
|
|
{
|
|
#ifdef __riscv_atomic
|
|
int32_t r;
|
|
do {
|
|
__asm__ __volatile__ (
|
|
"amoor.w %0, %2, %1\n"
|
|
: "=r" (r), "+A" (uart[UART_REG_TXFIFO])
|
|
: "r" (ch));
|
|
} while (r < 0);
|
|
#else
|
|
volatile uint32_t *tx = uart + UART_REG_TXFIFO;
|
|
while ((int32_t)(*tx) < 0);
|
|
*tx = ch;
|
|
#endif
|
|
}
|
|
|
|
int uart_getchar()
|
|
{
|
|
int32_t ch = uart[UART_REG_RXFIFO];
|
|
if (ch < 0) return -1;
|
|
return ch;
|
|
}
|
|
|
|
void query_uart(uintptr_t dtb)
|
|
{
|
|
uart = 0; // (void*)fdt_get_reg(dtb, "sifive,uart0");
|
|
if (!uart) return;
|
|
|
|
// Enable Rx/Tx channels
|
|
uart[UART_REG_TXCTRL] = UART_TXEN;
|
|
uart[UART_REG_RXCTRL] = UART_RXEN;
|
|
}
|
|
|