384 lines
13 KiB
C
384 lines
13 KiB
C
/****************************************************************************
|
|
* arch/arm/src/stm32/stm32_tickless.c
|
|
*
|
|
* Copyright (C) 2016 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.
|
|
*
|
|
****************************************************************************/
|
|
/****************************************************************************
|
|
* Tickless OS Support.
|
|
*
|
|
* When CONFIG_SCHED_TICKLESS is enabled, all support for timer interrupts
|
|
* is suppressed and the platform specific code is expected to provide the
|
|
* following custom functions.
|
|
*
|
|
* void up_timer_initialize(void): Initializes the timer facilities.
|
|
* Called early in the initialization sequence (by up_intialize()).
|
|
* int up_timer_gettime(FAR struct timespec *ts): Returns the current
|
|
* time from the platform specific time source.
|
|
* int up_timer_cancel(void): Cancels the interval timer.
|
|
* int up_timer_start(FAR const struct timespec *ts): Start (or re-starts)
|
|
* the interval timer.
|
|
*
|
|
* The RTOS will provide the following interfaces for use by the platform-
|
|
* specific interval timer implementation:
|
|
*
|
|
* void sched_timer_expiration(void): Called by the platform-specific
|
|
* logic when the interval timer expires.
|
|
*
|
|
****************************************************************************/
|
|
/****************************************************************************
|
|
* SAM34 Timer Usage
|
|
*
|
|
* This current implementation uses two timers: A one-shot timer to provide
|
|
* the timed events and a free running timer to provide the current time.
|
|
* Since timers are a limited resource, that could be an issue on some
|
|
* systems.
|
|
*
|
|
* We could do the job with a single timer if we were to keep the single
|
|
* timer in a free-running at all times. The STM32 timer/counters have
|
|
* 16-bit/32-bit counters with the capability to generate a compare interrupt
|
|
* when the timer matches a compare value but also to continue counting
|
|
* without stopping (giving another, different interrupt when the timer
|
|
* rolls over from 0xffffffff to zero). So we could potentially just set
|
|
* the compare at the number of ticks you want PLUS the current value of
|
|
* timer. Then you could have both with a single timer: An interval timer
|
|
* and a free-running counter with the same timer!
|
|
*
|
|
* Patches are welcome!
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <stdint.h>
|
|
#include <stdbool.h>
|
|
|
|
#include <nuttx/arch.h>
|
|
#include <debug.h>
|
|
|
|
#include "stm32_oneshot.h"
|
|
#include "stm32_freerun.h"
|
|
|
|
#ifdef CONFIG_SCHED_TICKLESS
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
#ifndef CONFIG_STM32_ONESHOT
|
|
# error CONFIG_STM32_ONESHOT must be selected for the Tickless OS option
|
|
#endif
|
|
|
|
#ifndef CONFIG_STM32_FREERUN
|
|
# error CONFIG_STM32_FREERUN must be selected for the Tickless OS option
|
|
#endif
|
|
|
|
#ifndef CONFIG_STM32_TICKLESS_FREERUN
|
|
# error CONFIG_STM32_TICKLESS_FREERUN must be selected for the Tickless OS option
|
|
#endif
|
|
|
|
#ifndef CONFIG_STM32_TICKLESS_ONESHOT
|
|
# error CONFIG_STM32_TICKLESS_ONESHOT must be selected for the Tickless OS option
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Private Types
|
|
****************************************************************************/
|
|
|
|
struct stm32_tickless_s
|
|
{
|
|
struct stm32_oneshot_s oneshot;
|
|
struct stm32_freerun_s freerun;
|
|
};
|
|
|
|
/****************************************************************************
|
|
* Private Data
|
|
****************************************************************************/
|
|
|
|
static struct stm32_tickless_s g_tickless;
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: stm32_oneshot_handler
|
|
*
|
|
* Description:
|
|
* Called when the one shot timer expires
|
|
*
|
|
* Input Parameters:
|
|
* None
|
|
*
|
|
* Returned Value:
|
|
* None
|
|
*
|
|
* Assumptions:
|
|
* Called early in the initialization sequence before any special
|
|
* concurrency protections are required.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static void stm32_oneshot_handler(void *arg)
|
|
{
|
|
tmrinfo("Expired...\n");
|
|
sched_timer_expiration();
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: up_timer_initialize
|
|
*
|
|
* Description:
|
|
* Initializes all platform-specific timer facilities. This function is
|
|
* called early in the initialization sequence by up_intialize().
|
|
* On return, the current up-time should be available from
|
|
* up_timer_gettime() and the interval timer is ready for use (but not
|
|
* actively timing.
|
|
*
|
|
* Provided by platform-specific code and called from the architecture-
|
|
* specific logic.
|
|
*
|
|
* Input Parameters:
|
|
* None
|
|
*
|
|
* Returned Value:
|
|
* None
|
|
*
|
|
* Assumptions:
|
|
* Called early in the initialization sequence before any special
|
|
* concurrency protections are required.
|
|
*
|
|
****************************************************************************/
|
|
|
|
void up_timer_initialize(void)
|
|
{
|
|
#ifdef CONFIG_SCHED_TICKLESS_LIMIT_MAX_SLEEP
|
|
uint64_t max_delay;
|
|
#endif
|
|
int ret;
|
|
|
|
/* Initialize the one-shot timer */
|
|
|
|
ret = stm32_oneshot_initialize(&g_tickless.oneshot,
|
|
CONFIG_STM32_TICKLESS_ONESHOT,
|
|
CONFIG_USEC_PER_TICK);
|
|
if (ret < 0)
|
|
{
|
|
tmrerr("ERROR: stm32_oneshot_initialize failed\n");
|
|
PANIC();
|
|
}
|
|
|
|
#ifdef CONFIG_SCHED_TICKLESS_LIMIT_MAX_SLEEP
|
|
/* Get the maximum delay of the one-shot timer in microseconds */
|
|
|
|
ret = stm32_oneshot_max_delay(&g_tickless.oneshot, &max_delay);
|
|
if (ret < 0)
|
|
{
|
|
tmrerr("ERROR: stm32_oneshot_max_delay failed\n");
|
|
PANIC();
|
|
}
|
|
|
|
/* Convert this to configured clock ticks for use by the OS timer logic */
|
|
|
|
max_delay /= CONFIG_USEC_PER_TICK;
|
|
if (max_delay > UINT32_MAX)
|
|
{
|
|
g_oneshot_maxticks = UINT32_MAX;
|
|
}
|
|
else
|
|
{
|
|
g_oneshot_maxticks = max_delay;
|
|
}
|
|
#endif
|
|
|
|
/* Initialize the free-running timer */
|
|
|
|
ret = stm32_freerun_initialize(&g_tickless.freerun,
|
|
CONFIG_STM32_TICKLESS_FREERUN,
|
|
CONFIG_USEC_PER_TICK);
|
|
if (ret < 0)
|
|
{
|
|
tmrerr("ERROR: stm32_freerun_initialize failed\n");
|
|
PANIC();
|
|
}
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: up_timer_gettime
|
|
*
|
|
* Description:
|
|
* Return the elapsed time since power-up (or, more correctly, since
|
|
* up_timer_initialize() was called). This function is functionally
|
|
* equivalent to:
|
|
*
|
|
* int clock_gettime(clockid_t clockid, FAR struct timespec *ts);
|
|
*
|
|
* when clockid is CLOCK_MONOTONIC.
|
|
*
|
|
* This function provides the basis for reporting the current time and
|
|
* also is used to eliminate error build-up from small errors in interval
|
|
* time calculations.
|
|
*
|
|
* Provided by platform-specific code and called from the RTOS base code.
|
|
*
|
|
* Input Parameters:
|
|
* ts - Provides the location in which to return the up-time.
|
|
*
|
|
* Returned Value:
|
|
* Zero (OK) is returned on success; a negated errno value is returned on
|
|
* any failure.
|
|
*
|
|
* Assumptions:
|
|
* Called from the the normal tasking context. The implementation must
|
|
* provide whatever mutual exclusion is necessary for correct operation.
|
|
* This can include disabling interrupts in order to assure atomic register
|
|
* operations.
|
|
*
|
|
****************************************************************************/
|
|
|
|
#ifndef CONFIG_CLOCK_TIMEKEEPING
|
|
|
|
int up_timer_gettime(FAR struct timespec *ts)
|
|
{
|
|
return stm32_freerun_counter(&g_tickless.freerun, ts);
|
|
}
|
|
|
|
#else
|
|
|
|
int up_timer_getcounter(FAR uint64_t *cycles)
|
|
{
|
|
return stm32_freerun_counter(&g_tickless.freerun, cycles);
|
|
}
|
|
|
|
#endif /* CONFIG_CLOCK_TIMEKEEPING */
|
|
|
|
/****************************************************************************
|
|
* Name: up_timer_getmask
|
|
*
|
|
* Description:
|
|
* To be provided
|
|
*
|
|
* Input Parameters:
|
|
* mask - Location to return the 64-bit mask
|
|
*
|
|
* Returned Value:
|
|
* None
|
|
*
|
|
****************************************************************************/
|
|
|
|
#ifdef CONFIG_CLOCK_TIMEKEEPING
|
|
void up_timer_getmask(FAR uint64_t *mask)
|
|
{
|
|
DEBUGASSERT(mask != NULL);
|
|
*mask = g_tickless.freerun.counter_mask;
|
|
}
|
|
#endif /* CONFIG_CLOCK_TIMEKEEPING */
|
|
|
|
/****************************************************************************
|
|
* Name: up_timer_cancel
|
|
*
|
|
* Description:
|
|
* Cancel the interval timer and return the time remaining on the timer.
|
|
* These two steps need to be as nearly atomic as possible.
|
|
* sched_timer_expiration() will not be called unless the timer is
|
|
* restarted with up_timer_start().
|
|
*
|
|
* If, as a race condition, the timer has already expired when this
|
|
* function is called, then that pending interrupt must be cleared so
|
|
* that up_timer_start() and the remaining time of zero should be
|
|
* returned.
|
|
*
|
|
* NOTE: This function may execute at a high rate with no timer running (as
|
|
* when pre-emption is enabled and disabled).
|
|
*
|
|
* Provided by platform-specific code and called from the RTOS base code.
|
|
*
|
|
* Input Parameters:
|
|
* ts - Location to return the remaining time. Zero should be returned
|
|
* if the timer is not active. ts may be zero in which case the
|
|
* time remaining is not returned.
|
|
*
|
|
* Returned Value:
|
|
* Zero (OK) is returned on success. A call to up_timer_cancel() when
|
|
* the timer is not active should also return success; a negated errno
|
|
* value is returned on any failure.
|
|
*
|
|
* Assumptions:
|
|
* May be called from interrupt level handling or from the normal tasking
|
|
* level. Interrupts may need to be disabled internally to assure
|
|
* non-reentrancy.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int up_timer_cancel(FAR struct timespec *ts)
|
|
{
|
|
return stm32_oneshot_cancel(&g_tickless.oneshot, ts);
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: up_timer_start
|
|
*
|
|
* Description:
|
|
* Start the interval timer. sched_timer_expiration() will be
|
|
* called at the completion of the timeout (unless up_timer_cancel
|
|
* is called to stop the timing.
|
|
*
|
|
* Provided by platform-specific code and called from the RTOS base code.
|
|
*
|
|
* Input Parameters:
|
|
* ts - Provides the time interval until sched_timer_expiration() is
|
|
* called.
|
|
*
|
|
* Returned Value:
|
|
* Zero (OK) is returned on success; a negated errno value is returned on
|
|
* any failure.
|
|
*
|
|
* Assumptions:
|
|
* May be called from interrupt level handling or from the normal tasking
|
|
* level. Interrupts may need to be disabled internally to assure
|
|
* non-reentrancy.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int up_timer_start(FAR const struct timespec *ts)
|
|
{
|
|
return stm32_oneshot_start(&g_tickless.oneshot, stm32_oneshot_handler, NULL, ts);
|
|
}
|
|
#endif /* CONFIG_SCHED_TICKLESS */
|