Subversion Repositories openrisc_2011-10-31

/*

 * UART interrupt test

 *

 * Tests UART and interrupt routines servicing them.

 *

 * Relies on UART 0 receiving external stimulus.

 *

 * Julius Baxter, julius.baxter@orsoc.se

 *

*/

#include "cpu-utils.h"

#include "spr-defs.h"

#include "board.h"

#include "uart.h"

#include "printf.h"

#include "int.h"

#include "orpsoc-defines.h"

#ifndef UART0

# error

# error UART0 missing and is required for UART interrupt (loopback) test

# error

#endif

#define UART_TX_BUF_MAX 256

struct uart_tx_ctrl

{

  char buf[UART_TX_BUF_MAX]; /* 256byte buffer to print */

  int buf_count;

  int tx_count;

};

volatile struct uart_tx_ctrl uart0_tx_ctrl;

/* Reset buffer counter */

void uart0_tx_buffer_init(void)

{

  uart0_tx_ctrl.buf_count = 0;

  uart0_tx_ctrl.tx_count = 0;

}

/* Add characters to be transmitted */

void uart0_tx_buffer_add(int numchars, char* buf)

{

  // If we're not currently transmitting, ie. nothign in the buffer, then

  // we should transmit after this.

  int start_tx = (numchars && !uart0_tx_ctrl.buf_count);

  while(numchars)

    {

      /* Not good if this gets used outside of interrupt. */

      uart0_tx_ctrl.buf[uart0_tx_ctrl.buf_count%UART_TX_BUF_MAX] = *buf++;

      uart0_tx_ctrl.buf_count++;

      numchars--;

    }

  if (start_tx)

    {

      uart_txint_enable(0);

      uart_putc_noblock(0, uart0_tx_ctrl.buf[uart0_tx_ctrl.tx_count%UART_TX_BUF_MAX]);

      uart0_tx_ctrl.tx_count++;

    }

}

void uart_int_handler(void* corenum);

void uart_int_handler(void* corenum)

{

  int core = *((int*)corenum);

  if (core)report(core);

  char iir = uart_get_iir(core);

  if ( (iir & UART_IIR_RLSI)  == UART_IIR_RLSI)

    uart_get_lsr(core); // Should clear this interrupt

  else if ( (iir & UART_IIR_RDI) == UART_IIR_RDI )

    {

      // Was potentially also a timeout. Do we care?

      // Data received. Pull from the fifo and echo back.

      char rxchar;

      while (uart_check_for_char(core))

        {

          rxchar = uart_getc(core);

          report(0xff & rxchar);

          //printf("RX char: %c\n",rxchar);

          uart0_tx_buffer_add(1, &rxchar);

          if (rxchar == 0x2a) // Exit simulation when RX char is '*'

            {

              report(0x8000000d);

              exit(0);

            }

        }

    }

  else if ( (iir & UART_IIR_THRI) ==  UART_IIR_THRI)

    {

      // Only trigered if we've set something to be transmitted

      // and enabled the interrupt.

      // Put next thing to be transmitted into buffer, check if it's

      // the last, if so, disable interrupts.

      if (uart0_tx_ctrl.buf_count == uart0_tx_ctrl.tx_count)

        {

          uart_txint_disable(core);

        }

      else // Transmit this byte

        {

          uart_putc_noblock(0, uart0_tx_ctrl.buf[uart0_tx_ctrl.tx_count%UART_TX_BUF_MAX]);

          uart0_tx_ctrl.tx_count++;

        }

    }

  else if ( (iir & UART_IIR_MSI) == UART_IIR_MSI )

    {

      // Just read the modem status register to clear this

      uart_get_msr(core);

    }

}

int main()

{

  int uart0_core = 0;

  int uart1_core = 1;

  /* Set up interrupt handler */

  int_init();

  /* Install UART core 0 interrupt handler */

  int_add(UART0_IRQ, uart_int_handler,(void*) &uart0_core);

  /* Install UART core 1 interrupt handler */

  //int_add(UART1_IRQ, uart_int_handler,(void*) &uart1_core);

  /* Enable interrupts in supervisor register */

  mtspr (SPR_SR, mfspr (SPR_SR) | SPR_SR_IEE);

  uart_init(uart0_core);

  uart_rxint_enable(uart0_core);

  uart0_tx_buffer_init();

  printf("\n\tUART interrupt test.\n");

  printf("\n\tType to see characters echoed\n");

  while(1); // will exit in the rx interrupt routine

}