arch/arm/src/imxrt/imxrt_timerisr.c

/****************************************************************************
 * arch/arm/src/imxrt/imxrt_timerisr.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/config.h>

#include <stdint.h>
#include <time.h>
#include <assert.h>
#include <debug.h>

#include <nuttx/arch.h>
#include <nuttx/power/pm.h>

#include <arch/board/board.h>

#include "nvic.h"
#include "clock/clock.h"
#include "arm_internal.h"
#include "chip.h"
#include "hardware/imxrt_ccm.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

#warning REVISIT these clock settings

/* Select MCU-specific settings
 *
 * The SysTick timer is driven by the output of the Main Clock (main_clk).
 */

#define IMXRT_SYSTICK_CLOCK  BOARD_CPU_FREQUENCY

/* The desired timer interrupt frequency is provided by the definition
 * CLK_TCK (see include/time.h).  CLK_TCK defines the desired number of
 * system clock ticks per second.  That value is a user configurable setting
 * that defaults to 100 (100 ticks per second = 10 MS interval).
 */

#define SYSTICK_RELOAD ((IMXRT_SYSTICK_CLOCK / CLK_TCK) - 1)

/* The size of the reload field is 24 bits.  Verify that the reload value
 * will fit in the reload register.
 */

#if SYSTICK_RELOAD > 0x00ffffff
#  error SYSTICK_RELOAD exceeds the range of the RELOAD register
#endif

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/

static int imxrt_timerisr(int irq, uint32_t *regs, void *arg);

#ifdef CONFIG_PM
static void up_pm_notify(struct pm_callback_s *cb, int dowmin,
                         enum pm_state_e pmstate);
static int  up_pm_prepare(struct pm_callback_s *cb, int domain,
                          enum pm_state_e pmstate);
#endif

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

#ifdef CONFIG_PM
static  struct pm_callback_s g_timer_pmcb =
{
  .notify  = up_pm_notify,
  .prepare = up_pm_prepare,
};
#endif

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Function:  imxrt_timerisr
 *
 * Description:
 *   The timer ISR will perform a variety of services for various portions
 *   of the systems.
 *
 ****************************************************************************/

static int imxrt_timerisr(int irq, uint32_t *regs, void *arg)
{
  /* Process timer interrupt */

  nxsched_process_timer();
  return 0;
}

/****************************************************************************
 * Name: up_pm_notify
 *
 * Description:
 *   Notify the driver of new power state. This callback is  called after
 *   all drivers have had the opportunity to prepare for the new power state.
 *
 * Input Parameters:
 *
 *    cb - Returned to the driver. The driver version of the callback
 *         structure may include additional, driver-specific state data at
 *         the end of the structure.
 *
 *    pmstate - Identifies the new PM state
 *
 * Returned Value:
 *   None - The driver already agreed to transition to the low power
 *   consumption state when when it returned OK to the prepare() call.
 *
 *
 ****************************************************************************/

#ifdef CONFIG_PM
static void up_pm_notify(struct pm_callback_s *cb, int domain,
                         enum pm_state_e pmstate)
{
  switch (pmstate)
    {
      case(PM_NORMAL):
        {
          /* Logic for PM_NORMAL goes here */
        }
        break;

      case(PM_IDLE):
        {
          /* Logic for PM_IDLE goes here */
        }
        break;

      case(PM_STANDBY):
        {
          /* Logic for PM_STANDBY goes here */
        }
        break;

      case(PM_SLEEP):
        {
          /* Logic for PM_SLEEP goes here */
        }
        break;

      default:

        /* Should not get here */

        break;
    }
}
#endif

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

/****************************************************************************
 * Function:  up_timer_initialize
 *
 * Description:
 *   This function is called during start-up to initialize the timer
 *   interrupt.
 *
 ****************************************************************************/

void up_timer_initialize(void)
{
  uint32_t regval;
#ifdef CONFIG_PM
  int ret;
#endif

  /* Configure SysTick to interrupt at the requested rate */

  putreg32(SYSTICK_RELOAD, NVIC_SYSTICK_RELOAD);
  putreg32(0, NVIC_SYSTICK_CURRENT);

  /* Attach the timer interrupt vector */

  irq_attach(IMXRT_IRQ_SYSTICK, (xcpt_t)imxrt_timerisr, NULL);

  /* Enable SysTick interrupts */

  regval = (NVIC_SYSTICK_CTRL_CLKSOURCE | NVIC_SYSTICK_CTRL_TICKINT |
            NVIC_SYSTICK_CTRL_ENABLE);
  putreg32(regval, NVIC_SYSTICK_CTRL);

#ifdef CONFIG_PM
  /* Register to receive power management callbacks */

  ret = pm_register(&g_timer_pmcb);
  DEBUGASSERT(ret == OK);
  UNUSED(ret);
#endif

  /* And enable the timer interrupt */

  up_enable_irq(IMXRT_IRQ_SYSTICK);
}