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arm: Simplify CPU counter support

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Use the standard ARMv7-M systick module for the ARMv7-M CPU counter
instead of DWT counter since the DWT counter is affected by power saving
states.

Use an inline function for _CPU_Counter_difference() for all ARM BSPs.

Update #3456.
This commit is contained in:
Sebastian Huber
2018-05-22 08:52:13 +02:00
parent 65f868cac6
commit 762fa62cca
24 changed files with 137 additions and 162 deletions
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78
bsps/arm/include/bsp/clock-armv7m.h Normal file
View File

@@ -0,0 +1,78 @@
/*
* Copyright (c) 2011, 2018 Sebastian Huber. All rights reserved.
*
* embedded brains GmbH
* Dornierstr. 4
* 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.
*/
#ifndef BSP_CLOCK_ARMV7M_H
#define BSP_CLOCK_ARMV7M_H
#include <rtems/score/armv7m.h>
#include <rtems/timecounter.h>
#include <bsp.h>
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
#ifdef ARM_MULTILIB_ARCH_V7M
typedef struct {
struct timecounter base;
uint32_t ticks;
} ARMV7M_Timecounter;
extern ARMV7M_Timecounter _ARMV7M_TC;
static inline uint32_t _ARMV7M_Clock_frequency(void)
{
#ifdef BSP_ARMV7M_SYSTICK_FREQUENCY
return BSP_ARMV7M_SYSTICK_FREQUENCY;
#else
volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
return ARMV7M_SYSTICK_CALIB_TENMS_GET(systick->calib) * 100;
#endif
}
static uint32_t _ARMV7M_Clock_counter(ARMV7M_Timecounter *tc)
{
volatile ARMV7M_Systick *systick;
rtems_interrupt_level level;
uint32_t interval;
uint32_t counter;
uint32_t ticks;
systick = _ARMV7M_Systick;
interval = systick->rvr;
rtems_interrupt_disable(level);
counter = systick->cvr;
ticks = tc->ticks;
if ((systick->csr & ARMV7M_SYSTICK_CSR_COUNTFLAG) != 0) {
ticks += interval;
tc->ticks = ticks;
}
counter = interval - counter + ticks;
rtems_interrupt_enable(level);
return counter;
}
#endif /* ARM_MULTILIB_ARCH_V7M */
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* BSP_CLOCK_ARMV7M_H */

9
bsps/arm/lpc176x/start/system-clocks.c
View File

@@ -118,12 +118,3 @@ CPU_Counter_ticks _CPU_Counter_read( void )
{
return lpc176x_get_timer1();
}
inline CPU_Counter_ticks _CPU_Counter_difference(
CPU_Counter_ticks second,
CPU_Counter_ticks first
)
{
return second - first;
}

149
bsps/arm/shared/clock/clock-armv7m.c
View File

@@ -1,8 +1,8 @@
/*
* Copyright (c) 2011-2012 Sebastian Huber. All rights reserved.
* Copyright (c) 2011, 2018 Sebastian Huber. All rights reserved.
*
* embedded brains GmbH
* Obere Lagerstr. 30
* Dornierstr. 4
* 82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
@@ -12,146 +12,97 @@
* http://www.rtems.org/license/LICENSE.
*/
#include <rtems.h>
#include <rtems/timecounter.h>
#include <rtems/score/armv7m.h>
#include <bsp/clock-armv7m.h>
#include <bsp.h>
#include <rtems.h>
#include <rtems/sysinit.h>
#ifdef ARM_MULTILIB_ARCH_V7M
/* This is defined in dev/clock/clockimpl.h */
static void Clock_isr(void *arg);
typedef struct {
rtems_timecounter_simple base;
void (*tick)(void);
bool countflag;
} ARMV7M_Timecounter;
ARMV7M_Timecounter _ARMV7M_TC;
static ARMV7M_Timecounter _ARMV7M_TC;
static uint32_t _ARMV7M_TC_systick_get(rtems_timecounter_simple *tc)
static uint32_t _ARMV7M_TC_get_timecount(struct timecounter *base)
{
volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
return systick->cvr;
return _ARMV7M_Clock_counter((ARMV7M_Timecounter *) base);
}
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 void _ARMV7M_TC_tick(void)
{
(*_ARMV7M_TC.tick)();
}
static void _ARMV7M_Systick_handler(void)
static void _ARMV7M_Clock_handler(void)
{
_ARMV7M_Interrupt_service_enter();
Clock_isr(NULL);
_ARMV7M_Interrupt_service_leave();
}
static void _ARMV7M_Systick_handler_install(void)
static void _ARMV7M_Clock_handler_install(void)
{
_ARMV7M_Set_exception_priority_and_handler(
ARMV7M_VECTOR_SYSTICK,
BSP_ARMV7M_SYSTICK_PRIORITY,
_ARMV7M_Systick_handler
_ARMV7M_Clock_handler
);
}
static void _ARMV7M_Systick_initialize(void)
static void _ARMV7M_Clock_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;
volatile ARMV7M_Systick *systick;
ARMV7M_Timecounter *tc;
systick = _ARMV7M_Systick;
tc = &_ARMV7M_TC;
systick->rvr = (uint32_t) interval;
systick->cvr = 0;
systick->csr = ARMV7M_SYSTICK_CSR_ENABLE
| ARMV7M_SYSTICK_CSR_TICKINT
| ARMV7M_SYSTICK_CSR_CLKSOURCE;
_ARMV7M_TC.tick = _ARMV7M_TC_systick_tick;
rtems_timecounter_simple_install(
&_ARMV7M_TC.base,
freq,
interval,
_ARMV7M_TC_systick_get_timecount
);
tc->base.tc_get_timecount = _ARMV7M_TC_get_timecount;
tc->base.tc_counter_mask = 0xffffffff;
tc->base.tc_frequency = _ARMV7M_Clock_frequency();
tc->base.tc_quality = RTEMS_TIMECOUNTER_QUALITY_CLOCK_DRIVER;
rtems_timecounter_install(&tc->base);
}
static void _ARMV7M_Systick_cleanup(void)
static void _ARMV7M_Clock_initialize_early(void)
{
volatile ARMV7M_Systick *systick;
uint32_t us_per_tick;
uint64_t freq;
uint32_t interval;
systick = _ARMV7M_Systick;
us_per_tick = rtems_configuration_get_microseconds_per_tick();
freq = _ARMV7M_Clock_frequency();
interval = (uint32_t) ((freq * us_per_tick) / 1000000);
systick->rvr = interval;
systick->cvr = 0;
systick->csr = ARMV7M_SYSTICK_CSR_ENABLE | ARMV7M_SYSTICK_CSR_CLKSOURCE;
}
RTEMS_SYSINIT_ITEM(
_ARMV7M_Clock_initialize_early,
RTEMS_SYSINIT_CPU_COUNTER,
RTEMS_SYSINIT_ORDER_FIRST
);
static void _ARMV7M_Clock_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()
_ARMV7M_Clock_initialize()
#define Clock_driver_support_install_isr(isr) \
_ARMV7M_Systick_handler_install()
_ARMV7M_Clock_handler_install()
#define Clock_driver_support_shutdown_hardware() \
_ARMV7M_Systick_cleanup()
_ARMV7M_Clock_cleanup()
/* Include shared source clock driver code */
#include "../../../shared/dev/clock/clockimpl.h"

37
bsps/arm/shared/cpucounter/cpucounter-armv7m.c
View File

@@ -1,5 +1,5 @@
/*
* Copyright (c) 2016 embedded brains GmbH. All rights reserved.
* Copyright (c) 2016, 2018 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Dornierstr. 4
@@ -12,43 +12,14 @@
* http://www.rtems.org/license/LICENSE.
*/
#include <rtems/score/armv7m.h>
#include <rtems/counter.h>
#include <rtems/sysinit.h>
#include <bsp.h>
#include <bsp/fatal.h>
#include <bsp/clock-armv7m.h>
uint32_t _CPU_Counter_frequency(void)
{
#ifdef BSP_ARMV7M_SYSTICK_FREQUENCY
return = BSP_ARMV7M_SYSTICK_FREQUENCY;
#else
volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
return ARMV7M_SYSTICK_CALIB_TENMS_GET(systick->calib) * 100;
#endif
return _ARMV7M_Clock_frequency();
}
CPU_Counter_ticks _CPU_Counter_read(void)
{
volatile ARMV7M_DWT *dwt = _ARMV7M_DWT;
return dwt->cyccnt;
return _ARMV7M_Clock_counter(&_ARMV7M_TC);
}
static void armv7m_cpu_counter_initialize(void)
{
bool cyccnt_enabled;
cyccnt_enabled = _ARMV7M_DWT_Enable_CYCCNT();
if (!cyccnt_enabled) {
bsp_fatal(BSP_ARM_ARMV7M_CPU_COUNTER_INIT);
}
}
RTEMS_SYSINIT_ITEM(
armv7m_cpu_counter_initialize,
RTEMS_SYSINIT_CPU_COUNTER,
RTEMS_SYSINIT_ORDER_FIRST
);