/**
 * @file
 *
 * @ingroup QorIQ
 *
 * @brief QorIQ clock configuration.
 */

/*
 * Copyright (c) 2011-2012 embedded brains GmbH.  All rights reserved.
 *
 *  embedded brains GmbH
 *  Obere Lagerstr. 30
 *  82178 Puchheim
 *  Germany
 *  <rtems@embedded-brains.de>
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rtems.com/license/LICENSE.
 *
 * $Id$
 */

#include <libcpu/powerpc-utility.h>

#include <bsp.h>
#include <bsp/qoriq.h>
#include <bsp/irq.h>

/* This is defined in clockdrv_shell.h */
static rtems_isr Clock_isr(void *arg);

static uint32_t qoriq_clock_nanoseconds_per_timer_tick;

static volatile qoriq_pic_global_timer *const qoriq_clock =
  #if QORIQ_CLOCK_TIMER < 4
    &qoriq.pic.gta [QORIQ_CLOCK_TIMER];
  #else
    &qoriq.pic.gtb [QORIQ_CLOCK_TIMER - 4];
  #endif

#define CLOCK_INTERRUPT (QORIQ_IRQ_GT_BASE + QORIQ_CLOCK_TIMER)

static void qoriq_clock_handler_install(rtems_isr_entry *old_isr)
{
  rtems_status_code sc = RTEMS_SUCCESSFUL;

  *old_isr = NULL;

  sc = qoriq_pic_set_affinity(
    CLOCK_INTERRUPT,
    ppc_processor_id()
  );
  if (sc != RTEMS_SUCCESSFUL) {
    rtems_fatal_error_occurred(0xdeadbeef);
  }

  sc = qoriq_pic_set_priority(
    CLOCK_INTERRUPT,
    QORIQ_PIC_PRIORITY_LOWEST,
    NULL
  );
  if (sc != RTEMS_SUCCESSFUL) {
    rtems_fatal_error_occurred(0xdeadbeef);
  }

  sc = rtems_interrupt_handler_install(
    CLOCK_INTERRUPT,
    "Clock",
    RTEMS_INTERRUPT_UNIQUE,
    Clock_isr,
    NULL
  );
  if (sc != RTEMS_SUCCESSFUL) {
    rtems_fatal_error_occurred(0xdeadbeef);
  }
}

static void qoriq_clock_initialize(void)
{
  uint32_t timer_frequency = BSP_bus_frequency / 8;
  uint32_t nanoseconds_per_second = 1000000000;
  uint32_t interval = (uint32_t) (((uint64_t) timer_frequency
    * (uint64_t) rtems_configuration_get_microseconds_per_tick()) / 1000000);

  qoriq_clock_nanoseconds_per_timer_tick =
    nanoseconds_per_second / timer_frequency;

  qoriq_clock->bcr = GTBCR_COUNT(interval);
}

static void qoriq_clock_cleanup(void)
{
  rtems_status_code sc = RTEMS_SUCCESSFUL;

  qoriq_clock->bcr = GTBCR_CI;

  sc = rtems_interrupt_handler_remove(
    CLOCK_INTERRUPT,
    Clock_isr,
    NULL
  );
  if (sc != RTEMS_SUCCESSFUL) {
    rtems_fatal_error_occurred(0xdeadbeef);
  }
}

static uint32_t qoriq_clock_nanoseconds_since_last_tick(void)
{
  uint32_t current = GTCCR_COUNT_GET(qoriq_clock->ccr);
  uint32_t base = qoriq_clock->bcr;

  return (base - current) * qoriq_clock_nanoseconds_per_timer_tick;
}

#define Clock_driver_support_at_tick()
#define Clock_driver_support_initialize_hardware() \
  qoriq_clock_initialize()
#define Clock_driver_support_install_isr(clock_isr, old_isr) \
  qoriq_clock_handler_install(&old_isr)
#define Clock_driver_support_shutdown_hardware() \
  qoriq_clock_cleanup()
#define Clock_driver_nanoseconds_since_last_tick \
  qoriq_clock_nanoseconds_since_last_tick

/* Include shared source clock driver code */
#include "../../../shared/clockdrv_shell.h"