#include "bsp/uart.h"

#include "bsp/mmio.h"
#include "bsp/soc.h"

#define UART_TXDATA    (BSP_UART_BASE + 0x00u)
#define UART_RXDATA    (BSP_UART_BASE + 0x04u)
#define UART_TXREADY   (BSP_UART_BASE + 0x08u)
#define UART_RXVALID   (BSP_UART_BASE + 0x0cu)
#define UART_CLOCKFREQ (BSP_UART_BASE + 0x10u)
#define UART_BAUDRATE  (BSP_UART_BASE + 0x14u)
#define UART_DIVISOR   (BSP_UART_BASE + 0x18u)

void bsp_uart_putc(char c)
{
  if (c == '\n') {
    bsp_uart_putc('\r');
  }
  while ((bsp_read32(UART_TXREADY) & 1u) == 0u) {
  }
  bsp_write32(UART_TXDATA, (uint32_t)(uint8_t)c);
}

int bsp_uart_getc_nonblocking(void)
{
  if ((bsp_read32(UART_RXVALID) & 1u) == 0u) {
    return -1;
  }
  return (int)(bsp_read32(UART_RXDATA) & 0xffu);
}

void bsp_uart_wait_tx_idle(void)
{
  while ((bsp_read32(UART_TXREADY) & 1u) == 0u) {
  }
}

void bsp_uart_init_baudrate(uint32_t clock_hz, uint32_t baudrate)
{
  if (clock_hz == 0u || baudrate == 0u) {
    return;
  }

  uint32_t divisor = (clock_hz + (baudrate / 2u)) / baudrate;
  if (divisor < 2u) {
    divisor = 2u;
  }

  bsp_uart_wait_tx_idle();
  bsp_write32(UART_CLOCKFREQ, clock_hz);
  bsp_write32(UART_BAUDRATE, baudrate);
  bsp_write32(UART_DIVISOR, divisor);
}

uint32_t bsp_uart_clock_hz(void)
{
  return bsp_read32(UART_CLOCKFREQ);
}

uint32_t bsp_uart_baudrate(void)
{
  return bsp_read32(UART_BAUDRATE);
}

uint32_t bsp_uart_divisor(void)
{
  return bsp_read32(UART_DIVISOR);
}