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/**
* @file
*
* @ingroup bsp_clock
*
* @brief Clock Tick Device Driver Shell
*/
/*
* COPYRIGHT (c) 1989-2014.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#include <stdlib.h>
#include <bsp.h>
#include <rtems/clockdrv.h>
#include <rtems/score/percpu.h>
#include <rtems/score/smpimpl.h>
#include <rtems/score/watchdogimpl.h>
#ifdef Clock_driver_nanoseconds_since_last_tick
#error "Update driver to use the timecounter instead of nanoseconds extension"
#endif
/**
* @defgroup bsp_clock Clock Support
*
* @ingroup bsp_shared
*
* @brief Clock support
*
*/
#if CLOCK_DRIVER_USE_FAST_IDLE && CLOCK_DRIVER_ISRS_PER_TICK
#error "Fast Idle PLUS n ISRs per tick is not supported"
#endif
/**
* @brief Do nothing by default.
*/
#ifndef Clock_driver_support_install_isr
#define Clock_driver_support_install_isr(isr)
#endif
/**
* @brief This method is rarely used so default it.
*/
#ifndef Clock_driver_support_find_timer
#define Clock_driver_support_find_timer()
#endif
/**
* @brief Do nothing by default.
*/
#ifndef Clock_driver_support_at_tick
#define Clock_driver_support_at_tick()
#endif
/**
* @brief Do nothing by default.
*/
#ifndef Clock_driver_support_set_interrupt_affinity
#define Clock_driver_support_set_interrupt_affinity(online_processors)
#endif
/*
* A specialized clock driver may use for example rtems_timecounter_tick_simple()
* instead of the default.
*/
#ifndef Clock_driver_timecounter_tick
static void Clock_driver_timecounter_tick( void )
{
#if defined(CLOCK_DRIVER_USE_DUMMY_TIMECOUNTER)
rtems_clock_tick();
#elif defined(RTEMS_SMP) && defined(CLOCK_DRIVER_USE_ONLY_BOOT_PROCESSOR)
uint32_t cpu_count = _SMP_Get_processor_count();
uint32_t cpu_index;
for ( cpu_index = 0 ; cpu_index < cpu_count ; ++cpu_index ) {
Per_CPU_Control *cpu;
cpu = _Per_CPU_Get_by_index( cpu_index );
if ( _Per_CPU_Is_boot_processor( cpu ) ) {
rtems_timecounter_tick();
} else if ( _Processor_mask_Is_set( _SMP_Get_online_processors(), cpu_index ) ) {
_Watchdog_Tick( cpu );
}
}
#else
rtems_timecounter_tick();
#endif
}
#endif
/**
* @brief ISRs until next clock tick
*/
#if CLOCK_DRIVER_ISRS_PER_TICK
volatile uint32_t Clock_driver_isrs;
#endif
/**
* @brief Clock ticks since initialization
*/
volatile uint32_t Clock_driver_ticks;
#ifdef Clock_driver_support_shutdown_hardware
void Clock_exit( void );
#endif
/**
* @brief Clock_isr
*
* This is the clock tick interrupt handler.
*
* @param vector Vector number.
*/
#if defined(BSP_FEATURE_IRQ_EXTENSION) || \
(CPU_SIMPLE_VECTORED_INTERRUPTS != TRUE)
void Clock_isr(void *arg);
void Clock_isr(void *arg)
{
#else
rtems_isr Clock_isr(rtems_vector_number vector);
rtems_isr Clock_isr(
rtems_vector_number vector
)
{
#endif
/*
* Accurate count of ISRs
*/
Clock_driver_ticks += 1;
#if CLOCK_DRIVER_USE_FAST_IDLE
{
struct timecounter *tc = _Timecounter;
uint64_t us_per_tick = rtems_configuration_get_microseconds_per_tick();
uint32_t interval = (uint32_t)
((tc->tc_frequency * us_per_tick) / 1000000);
Clock_driver_timecounter_tick();
if (!rtems_configuration_is_smp_enabled()) {
while (
_Thread_Heir == _Thread_Executing && _Thread_Executing->is_idle
) {
ISR_lock_Context lock_context;
_Timecounter_Acquire(&lock_context);
_Timecounter_Tick_simple(
interval,
(*tc->tc_get_timecount)(tc),
&lock_context
);
}
}
Clock_driver_support_at_tick();
}
#else
/*
* Do the hardware specific per-tick action.
*
* The counter/timer may or may not be set to automatically reload.
*/
Clock_driver_support_at_tick();
#if CLOCK_DRIVER_ISRS_PER_TICK
/*
* The driver is multiple ISRs per clock tick.
*/
if ( !Clock_driver_isrs ) {
Clock_driver_timecounter_tick();
Clock_driver_isrs = CLOCK_DRIVER_ISRS_PER_TICK;
}
Clock_driver_isrs--;
#else
/*
* The driver is one ISR per clock tick.
*/
Clock_driver_timecounter_tick();
#endif
#endif
}
#ifdef Clock_driver_support_shutdown_hardware
/**
* @brief Clock_exit
*
* This routine allows the clock driver to exit by masking the interrupt and
* disabling the clock's counter.
*/
void Clock_exit( void )
{
Clock_driver_support_shutdown_hardware();
/* do not restore old vector */
}
#endif
/**
* @brief Clock_initialize
*
* This routine initializes the clock driver.
*
* @param[in] major Clock device major number.
* @param[in] minor Clock device minor number.
* @param[in] parg Pointer to optional device driver arguments
*
* @retval rtems_device_driver status code
*/
rtems_device_driver Clock_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
Clock_driver_ticks = 0;
/*
* Find timer -- some BSPs search buses for hardware timer
*/
Clock_driver_support_find_timer();
/*
* Install vector
*/
Clock_driver_support_install_isr( Clock_isr );
#ifdef RTEMS_SMP
Clock_driver_support_set_interrupt_affinity(
_SMP_Get_online_processors()
);
#endif
/*
* Now initialize the hardware that is the source of the tick ISR.
*/
Clock_driver_support_initialize_hardware();
#ifdef Clock_driver_support_shutdown_hardware
atexit( Clock_exit );
#endif
/*
* If we are counting ISRs per tick, then initialize the counter.
*/
#if CLOCK_DRIVER_ISRS_PER_TICK
Clock_driver_isrs = CLOCK_DRIVER_ISRS_PER_TICK_VALUE;
#endif
return RTEMS_SUCCESSFUL;
}
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