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/*
* Copyright (c) 2011-2012 Sebastian Huber. 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.org/license/LICENSE.
*/
#include <rtems.h>
#include <rtems/timecounter.h>
#include <rtems/score/armv7m.h>
#include <bsp.h>
#ifdef ARM_MULTILIB_ARCH_V7M
/* This is defined in clockdrv_shell.h */
static void Clock_isr(void *arg);
typedef struct {
rtems_timecounter_simple base;
void (*tick)(void);
bool countflag;
} ARMV7M_Timecounter;
static ARMV7M_Timecounter _ARMV7M_TC;
static uint32_t _ARMV7M_TC_systick_get(rtems_timecounter_simple *tc)
{
volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
return systick->cvr;
}
static bool _ARMV7M_TC_systick_is_pending(rtems_timecounter_simple *base)
{
ARMV7M_Timecounter *tc = (ARMV7M_Timecounter *) base;
rtems_interrupt_level level;
bool countflag;
rtems_interrupt_disable(level);
countflag = tc->countflag;
if (!countflag) {
volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
countflag = ((systick->csr & ARMV7M_SYSTICK_CSR_COUNTFLAG) != 0);
tc->countflag = countflag;
}
rtems_interrupt_enable(level);
return countflag;
}
static uint32_t _ARMV7M_TC_systick_get_timecount(struct timecounter *tc)
{
return rtems_timecounter_simple_downcounter_get(
tc,
_ARMV7M_TC_systick_get,
_ARMV7M_TC_systick_is_pending
);
}
static void _ARMV7M_TC_systick_at_tick(rtems_timecounter_simple *base)
{
ARMV7M_Timecounter *tc = (ARMV7M_Timecounter *) base;
volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
tc->countflag = false;
/* Clear COUNTFLAG */
systick->csr;
}
static void _ARMV7M_TC_systick_tick(void)
{
rtems_timecounter_simple_downcounter_tick(
&_ARMV7M_TC.base,
_ARMV7M_TC_systick_get,
_ARMV7M_TC_systick_at_tick
);
}
static uint32_t _ARMV7M_TC_dwt_get_timecount(struct timecounter *tc)
{
volatile ARMV7M_DWT *dwt = _ARMV7M_DWT;
return dwt->cyccnt;
}
static void _ARMV7M_TC_dwt_tick(void)
{
rtems_timecounter_tick();
}
static void _ARMV7M_TC_tick(void)
{
(*_ARMV7M_TC.tick)();
}
static void _ARMV7M_Systick_handler(void)
{
_ARMV7M_Interrupt_service_enter();
Clock_isr(NULL);
_ARMV7M_Interrupt_service_leave();
}
static void _ARMV7M_Systick_handler_install(void)
{
_ARMV7M_Set_exception_priority_and_handler(
ARMV7M_VECTOR_SYSTICK,
BSP_ARMV7M_SYSTICK_PRIORITY,
_ARMV7M_Systick_handler
);
}
static void _ARMV7M_Systick_initialize(void)
{
volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
#ifdef BSP_ARMV7M_SYSTICK_FREQUENCY
uint64_t freq = BSP_ARMV7M_SYSTICK_FREQUENCY;
#else
uint64_t freq = ARMV7M_SYSTICK_CALIB_TENMS_GET(systick->calib) * 100ULL;
#endif
uint64_t us_per_tick = rtems_configuration_get_microseconds_per_tick();
uint64_t interval = (freq * us_per_tick) / 1000000ULL;
bool cyccnt_enabled;
systick->rvr = (uint32_t) interval;
systick->cvr = 0;
systick->csr = ARMV7M_SYSTICK_CSR_ENABLE
| ARMV7M_SYSTICK_CSR_TICKINT
| ARMV7M_SYSTICK_CSR_CLKSOURCE;
cyccnt_enabled = _ARMV7M_DWT_Enable_CYCCNT();
if (cyccnt_enabled) {
_ARMV7M_TC.base.tc.tc_get_timecount = _ARMV7M_TC_dwt_get_timecount;
_ARMV7M_TC.base.tc.tc_counter_mask = 0xffffffff;
_ARMV7M_TC.base.tc.tc_frequency = freq;
_ARMV7M_TC.base.tc.tc_quality = RTEMS_TIMECOUNTER_QUALITY_CLOCK_DRIVER;
_ARMV7M_TC.tick = _ARMV7M_TC_dwt_tick;
rtems_timecounter_install(&_ARMV7M_TC.base.tc);
} else {
_ARMV7M_TC.tick = _ARMV7M_TC_systick_tick;
rtems_timecounter_simple_install(
&_ARMV7M_TC.base,
freq,
interval,
_ARMV7M_TC_systick_get_timecount
);
}
}
static void _ARMV7M_Systick_cleanup(void)
{
volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
systick->csr = 0;
}
#define Clock_driver_timecounter_tick() _ARMV7M_TC_tick()
#define Clock_driver_support_initialize_hardware() \
_ARMV7M_Systick_initialize()
#define Clock_driver_support_install_isr(isr) \
_ARMV7M_Systick_handler_install()
#define Clock_driver_support_shutdown_hardware() \
_ARMV7M_Systick_cleanup()
/* Include shared source clock driver code */
#include "../../../../shared/clockdrv_shell.h"
#endif /* ARM_MULTILIB_ARCH_V7M */
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