/****************************************************************************
 * arch/arm/src/armv7-a/arm_perf.c
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/arch.h>
#include <nuttx/clock.h>

#include "arm_internal.h"
#include "sctlr.h"

#ifdef CONFIG_ARCH_PERF_EVENTS

/****************************************************************************
 * Private Data
 ****************************************************************************/

static unsigned long g_cpu_freq = ULONG_MAX;

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: up_perf_*
 *
 * Description:
 *   The first interface simply provides the current time value in unknown
 *   units.  NOTE:  This function may be called early before the timer has
 *   been initialized.  In that event, the function should just return a
 *   start time of zero.
 *
 *   Nothing is assumed about the units of this time value.  The following
 *   are assumed, however: (1) The time is an unsigned integer value, (2)
 *   the time is monotonically increasing, and (3) the elapsed time (also
 *   in unknown units) can be obtained by subtracting a start time from
 *   the current time.
 *
 *   The second interface simple converts an elapsed time into well known
 *   units.
 *
 ****************************************************************************/

void up_perf_init(void *arg)
{
  g_cpu_freq = (unsigned long)(uintptr_t)arg;

  cp15_pmu_uer(PMUER_UME);
  cp15_pmu_pmcr(PMCR_E);
  cp15_pmu_cesr(PMCESR_CCES);
}

unsigned long up_perf_getfreq(void)
{
  return g_cpu_freq;
}

unsigned long up_perf_gettime(void)
{
  return cp15_pmu_rdccr();
}

void up_perf_convert(unsigned long elapsed, struct timespec *ts)
{
  unsigned long left;

  ts->tv_sec  = elapsed / g_cpu_freq;
  left        = elapsed - ts->tv_sec * g_cpu_freq;
  ts->tv_nsec = NSEC_PER_SEC * (uint64_t)left / g_cpu_freq;
}
#endif