nuttx/arch/arm/src/imxrt/imxrt_timerisr.c

/****************************************************************************
 * arch/arm/src/imxrt/imxrt_timerisr.c
 *
 *   Copyright (C) 2018 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

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

#include <nuttx/config.h>

#include <stdint.h>
#include <time.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 "up_internal.h"
#include "up_arch.h"

#include "chip.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 */

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

void arm_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 */

  (void)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);
}