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/* tick.c -- Tests all aspects of the tick timer

   Copyright (C) 2005 György `nog' Jeney, nog@sdf.lonestar.org

This file is part of OpenRISC 1000 Architectural Simulator.

This program is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2 of the License, or

(at your option) any later version.

This program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program; if not, write to the Free Software

Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */

#include "spr_defs.h"

#include "support.h"

#define ASSERT(x) ((x)? printf(" Test succeeded %s:%i\n", __FILE__, __LINE__) : fail (__FILE__, __LINE__))

void fail (char *func, int line)

{

#ifndef __FUNCTION__

#define __FUNCTION__ "?"

#endif

  printf ("Test failed in %s:%i\n", func, line);

  report(0xeeeeeeee);

  exit (1);

}

static volatile int tick_cnt = 0;

static int clear_ip = 1;

void tick_int(void)

{

  int ttcr = mfspr(SPR_TTCR);

  int ttmr = mfspr(SPR_TTMR);

  /* Make sure that the tick timer interrupt pending bit is set */

  ASSERT(mfspr(SPR_TTMR) & SPR_TTMR_IP);

  tick_cnt++;

  /* Clear interrupt (Write a 0 to SPR_TTMR_IP) */

  /* If we programmed a one-shot timer, make sure to disable the interrupts,

   * else we'd get a spurious interrupt */

  if((ttmr & SPR_TTMR_M) != 0x80000000)

    mtspr(SPR_TTMR, mfspr(SPR_TTMR) & ~SPR_TTMR_IP);

  else

    mtspr(SPR_TTMR, mfspr(SPR_TTMR) & ~(SPR_TTMR_IP | SPR_TTMR_IE));

}

void tick_int_spurious(void)

{

  /* Make sure that the tick timer interrupt pending bit is set */

  ASSERT(mfspr(SPR_TTMR) & SPR_TTMR_IP);

  /* Clear interrupt (Write a 0 to SPR_TTMR_IP) */

  if(clear_ip)

    mtspr(SPR_TTMR, mfspr(SPR_TTMR) & ~SPR_TTMR_IP);

  /* Make sure we actually get a spurious interrupt */

  if(++tick_cnt == 5)

    /* We should get spurious tick interrupts so disable it */

    mtspr(SPR_TTMR, 0);

}

/* Does nothing for a small amount of time (waiting for TTCR to increment) */

void waste_time(void)

{

  int i;

  volatile int x;

  for(i = 0; i < 50; i++)

    x = i;

}

/* Waits for a tick timer exception */

void wait_match(void)

{

  while(!tick_cnt);

  tick_cnt = 0;

}

int main()

{

  int ttcr;

  excpt_tick = (unsigned long)tick_int;

  /* Enable tick interrupt */

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

  /* Disable timer */

  mtspr(SPR_TTMR, 0);

  mtspr(SPR_TTCR, 0);

  /* Waste some time to check if the timer is really disabled */

  waste_time();

  /* Timer is disabled and shouldn't count, TTCR should still be 0 */

  ASSERT(mfspr(SPR_TTCR) == 0);

  /* Start timer in continous timeing mode.  Enable timer interrupt and set the

   * value to match */

  mtspr(SPR_TTMR, (3 << 30) | SPR_TTMR_IE | 0x100);

  /* Wait for the timer to count up to the match value */

  wait_match();

  ttcr = mfspr(SPR_TTCR);

  waste_time();

  /* The timer should have kept counting and our saved ttcr should not be the

   * same as SPR_TTCR */

  ASSERT(ttcr < mfspr(SPR_TTCR));

  mtspr(SPR_TTMR, 0);

  ttcr = mfspr(SPR_TTCR);

  /* Restart the timer */

  mtspr(SPR_TTMR, (3 << 30));

  waste_time();

  /* The timer should have carried on from what was SPR_TTCR when we started it.

   */

  ASSERT(ttcr < mfspr(SPR_TTCR));

  mtspr(SPR_TTMR, 0);

  ttcr = mfspr(SPR_TTCR);

  waste_time();

  /* Timer should be disabled and should not have counted */

  ASSERT(ttcr == mfspr(SPR_TTCR));

  /* Stop the timer when a match occured */

  mtspr(SPR_TTCR, 0);

  mtspr(SPR_TTMR, (2 << 30) | SPR_TTMR_IE | 0x100);

  wait_match();

  ttcr = mfspr(SPR_TTCR);

  waste_time();

  /* The timer should have stoped and thus SPR_TTCR sould = ttcr */

  ASSERT(ttcr == mfspr(SPR_TTCR));

  /* The counter should still indicate one-shot mode */

  ASSERT((mfspr(SPR_TTMR) >> 30) == 2);

  /* Set auto-restarting timer */

  mtspr(SPR_TTMR, 0);

  mtspr(SPR_TTCR, 0);

  mtspr(SPR_TTMR, (1 << 30) | SPR_TTMR_IE | 0x1000);

  wait_match();

  ttcr = mfspr(SPR_TTCR);

  wait_match();

  /* Disable timer */

  mtspr(SPR_TTMR, 0);

  /* Start a one-shot counter but keep interrupts disabled */

  mtspr(SPR_TTCR, 0);

  mtspr(SPR_TTMR, (2 << 30) | 0x100);

  /* Wait for the counter to stop */

  while(mfspr(SPR_TTCR) != 0x100);

  /* Make sure the counter has actually stopped */

  waste_time();

  ASSERT(mfspr(SPR_TTCR) == 0x100);

  ASSERT(tick_cnt == 0);

  /* SPR_TTMR_IP should not be set */

  ASSERT(!(mfspr(SPR_TTMR) & SPR_TTMR_IP));

  /* Start a perpetual counter (makeing sure that no interrupts occur while it's

   * counting) */

  mtspr(SPR_TTMR, 0);

  mtspr(SPR_TTCR, 0);

  mtspr(SPR_TTMR, (3 << 30) | 0x100);

  while(mfspr(SPR_TTCR) < 0x100);

  waste_time();

  ASSERT(mfspr(SPR_TTCR) > 0x100);

  ASSERT(tick_cnt == 0);

  ASSERT(!(mfspr(SPR_TTMR) & SPR_TTMR_IP));

  /* Disable the timer interrupt */

  mtspr(SPR_SR, mfspr(SPR_SR) & ~SPR_SR_TEE);

  /* Set one-shot timer */

  mtspr(SPR_TTCR, 0);

  mtspr(SPR_TTMR, (2 << 30) | SPR_TTMR_IE | 0x100);

  while(!(mfspr(SPR_TTMR) & SPR_TTMR_IP));

  /* Give some time for a potential interrupt to occur */

  waste_time();

  /* No interrupt should have occured */

  ASSERT(tick_cnt == 0);

  /* Enable tick interrupt */

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

  /* Test Setting TTCR while counting */

  mtspr(SPR_TTMR, 0);

  mtspr(SPR_TTCR, 0);

  mtspr(SPR_TTMR, (3 << 30) | 0x3000);

  while(mfspr(SPR_TTCR) < 0x30000);

  waste_time();

  mtspr(SPR_TTCR, 0x50);

  waste_time();

  ttcr = mfspr(SPR_TTCR);

  ASSERT(ttcr > 0x50 && ttcr < 0x30000);

  mtspr(SPR_TTMR, 0);

  /* Set ttcr to a high value */

  mtspr(SPR_TTCR, 0x20000);

  /* Now, start timer in one-shot mode */

  mtspr(SPR_TTMR, (2 << 30) | SPR_TTMR_IE | 0x100);

  /* The counter should start counting from 0x20000 and wrap around to 0x100

   * causeing an interrupt */

  waste_time();

  ASSERT(mfspr(SPR_TTCR) > 0x20000);

  wait_match();

  ASSERT(1);

  /* If TTCR is greater than TTMR_PERIOD then the interrupt gets delivered after

   * TTCR wraps around to 0 and counts to SPR_TTMR_PERIOD */

  mtspr(SPR_TTMR, 0);

  mtspr(SPR_TTCR, 0xffffc00);

  mtspr(SPR_TTMR, (1 << 30) | SPR_TTMR_IE | 0x10000);

  wait_match();

  ASSERT(1);

  /* test continuous mode */

  mtspr(SPR_TTMR, 0);

  mtspr(SPR_TTCR, 0xffffc00);

  mtspr(SPR_TTMR, (3 << 30) | SPR_TTMR_IE | 0x10000);

  wait_match();

  mtspr(SPR_TTMR, 0);

  ASSERT(1);

  excpt_tick = (unsigned long)tick_int_spurious;

  /* Make sure sure that TTMR_PERIOD is not 0!! */

  mtspr(SPR_TTMR, 1);

  /* Set SPR_TTMR_PERIOD to some value, while keeping the timer disabled */

  mtspr(SPR_TTCR, 0);

  mtspr(SPR_TTMR, SPR_TTMR_IE | 0x100);

  /* Set SPR_TTCR with the same value */

  mtspr(SPR_TTCR, 0x100);

  while(tick_cnt != 5);

  tick_cnt = 0;

  ASSERT(mfspr(SPR_TTCR) == 0x100);

  /* Test setting TTCR first then TTMR */

  mtspr(SPR_TTCR, 0x101);

  mtspr(SPR_TTMR, SPR_TTMR_IE | 0x101);

  while(tick_cnt != 5);

  tick_cnt = 0;

  ASSERT(mfspr(SPR_TTCR) == 0x101);

  /* Set countinous counter, but make sure we never clear the TTMR_IP bit */

  clear_ip = 0;

  mtspr(SPR_TTCR, 0);

  mtspr(SPR_TTMR, (3 << 30) | SPR_TTMR_IE | 0x100);

  while(tick_cnt != 5);

  report(0xdeaddead);

  return 0;

}