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STM32: Add a experimental oneshot, lower-half driver for STM32

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This commit is contained in:
Gregory Nutt 2016-08-11 14:07:43 -06:00
parent 9de2c28656
commit 1bb93021df
2 changed files with 338 additions and 8 deletions
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325
arch/arm/src/stm32/stm32_oneshot_lowerhalf.c Normal file
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@ -0,0 +1,325 @@
/****************************************************************************
* arch/arm/src/stm32/stm32_waste.c
*
* Copyright (C) 2016 Gregory Nutt. All rights reserved.
* Authors: 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <time.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/irq.h>
#include <nuttx/timers/oneshot.h>
#include "stm32_oneshot.h"
/****************************************************************************
* Private Types
****************************************************************************/
/* This structure describes the state of the oneshot timer lower-half driver */
struct stm32_oneshot_lowerhalf_s
{
/* This is the part of the lower half driver that is visible to the upper-
* half client of the driver.
*/
struct stm32_oneshot_lowerhalf_s lh;
/* Private lower half data follows */
struct stm32_oneshot_s oneshot; /* STM32-specific oneshot state */
oneshot_callback_t callback; /* internal handler that receives callback */
FAR void *arg; /* Argument that is passed to the handler */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static void stm32_oneshot_handler(void *arg);
static int stm32_max_delay(FAR struct oneshot_lowerhalf_s *lower,
FAR uint64_t *usec);
static int stm32_start(FAR struct oneshot_lowerhalf_s *lower,
oneshot_callback_t callback, FAR void *arg,
FAR const struct timespec *ts);
static int stm32_cancel(struct oneshot_lowerhalf_s *lower,
FAR struct timespec *ts);
/****************************************************************************
* Private Data
****************************************************************************/
/* Lower half operations */
static const struct oneshot_operations_s g_oneshot_ops =
{
.max_delay = stm32_max_delay,
.start = stm32_start,
.cancel = stm32_cancel,
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: stm32_oneshot_handler
*
* Description:
* Timer expiration handler
*
* Input Parameters:
* arg - Should be the same argument provided when stm32_oneshot_start()
* was called.
*
* Returned Value:
* None
*
****************************************************************************/
static void stm32_oneshot_handler(void *arg)
{
FAR struct stm32_oneshot_lowerhalf_s *priv =
(FAR struct stm32_oneshot_lowerhalf_s *)lower;
oneshot_handler_t callback;
FAR void *arg;
DEBUGASSERT(priv != NULL);
/* Perhaps the callback was nullified in a race condition with
* stm32_cancel?
*/
if (priv->callback)
{
/* Sample and nullify BEFORE executing callback (in case the callback
* restarts the oneshot).
*/
callback = priv->callback;
arg = priv->arg;
priv->callback = NULL;
priv->arg = NULL;
/* Then perform the callback */
callback(&priv->lh, arg);
}
}
/****************************************************************************
* Name: stm32_max_delay
*
* Description:
* Determine the maximum delay of the one-shot timer (in microseconds)
*
* Input Parameters:
* lower An instance of the lower-half oneshot state structure. This
* structure must have been previously initialized via a call to
* oneshot_initialize();
* usec The user-provided location in which to return the maxumum delay
* in microseconds.
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned
* on failure.
*
****************************************************************************/
static int stm32_max_delay(FAR struct oneshot_lowerhalf_s *lower,
FAR uint64_t *usec)
{
FAR struct stm32_oneshot_lowerhalf_s *priv =
(FAR struct stm32_oneshot_lowerhalf_s *)lower;
DEBUGASSERT(priv != NULL);
return stm32_oneshot_max_delay(&priv->oneshot, usec);
}
/****************************************************************************
* Name: stm32_start
*
* Description:
* Start the oneshot timer
*
* Input Parameters:
* lower An instance of the lower-half oneshot state structure. This
* structure must have been previously initialized via a call to
* oneshot_initialize();
* handler The function to call when when the oneshot timer expires.
* arg An opaque argument that will accompany the callback.
* ts Provides the duration of the one shot timer.
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned
* on failure.
*
****************************************************************************/
static int stm32_start(FAR struct oneshot_lowerhalf_s *lower,
oneshot_callback_t callback, FAR void *arg,
FAR const struct timespec *ts)
{
FAR struct stm32_oneshot_lowerhalf_s *priv =
(FAR struct stm32_oneshot_lowerhalf_s *)lower;
irqstate_t flags;
int ret;
DEBUGASSERT(priv != NULL);
/* Save the callback information and start the timer */
flags = enter_critical_section();
priv->callback = callback;
priv->arg = arg;
ret = stm32_oneshot_start(&priv->lh, stm32_oneshot_handler,
priv, ts);
leave_critical_section(flags);
if (ret < 0)
{
tmrerr("ERROR: stm32_oneshot_start failed: %d\n", flags);
}
return ret;
}
/****************************************************************************
* Name: stm32_cancel
*
* Description:
* Cancel the oneshot timer and return the time remaining on the timer.
*
* NOTE: This function may execute at a high rate with no timer running (as
* when pre-emption is enabled and disabled).
*
* Input Parameters:
* lower Caller allocated instance of the oneshot state structure. This
* structure must have been previously initialized via a call to
* oneshot_initialize();
* ts The location in which to return the time remaining on the
* oneshot timer. A time of zero is returned if the timer is
* not running.
*
* 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.
*
****************************************************************************/
static int stm32_cancel(struct oneshot_lowerhalf_s *lower,
FAR struct timespec *ts);
{
FAR struct stm32_oneshot_lowerhalf_s *priv =
(FAR struct stm32_oneshot_lowerhalf_s *)lower;
irqstate_t flags;
int ret;
DEBUGASSERT(priv != NULL);
/* Cancel the timer */
flags = enter_critical_section();
ret = stm32_oneshot_cancel(&priv->oneshot, ts);
priv->callback = NULL;
priv->arg = NULL;
leave_critical_section(flags);
if (ret < 0)
{
tmrerr("ERROR: stm32_oneshot_cancel failed: %d\n", flags);
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: oneshot_initialize
*
* Description:
* Initialize the oneshot timer and return a oneshot lower half driver
* instance.
*
* Input Parameters:
* chan Timer counter channel to be used.
* resolution The required resolution of the timer in units of
* microseconds. NOTE that the range is restricted to the
* range of uint16_t (excluding zero).
*
* Returned Value:
* On success, a non-NULL instance of the oneshot lower-half driver is
* returned. NULL is return on any failure.
*
****************************************************************************/
FAR struct oneshot_lowerhalf_s *oneshot_initialize(int chan,
uint16_t resolution)
{
FAR struct stm32_oneshot_lowerhalf_s *priv;
int ret;
/* Allocate an instance of the lower half driver */
priv = (FAR struct stm32_oneshot_lowerhalf_s *)
kmm_zalloc(sizeof(struct stm32_oneshot_lowerhalf_s));
if (priv == NULL)
{
tmrerr("ERROR: Failed to initialized state structure\n");
return NULL;
}
ret = stm32_oneshot_initialize(&priv->oneshot, chan, resolution);
if (ret < 0)
{
tmrerr("ERROR: Failed to initialized state structure\n");
kmm_free(priv);
return NULL;
}
return &priv->lh;
}

21
include/nuttx/timers/oneshot.h
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@ -131,23 +131,27 @@
* arg - The opaque argument provided when the interrupt was registered
*/
typedef void (*oneshot_callback_t)(FAR struct oneshot_dev_s *lower,
void *arg);
struct oneshot_lowerhalf_s;
typedef void (*oneshot_callback_t)(FAR struct oneshot_lowerhalf_s *lower,
FAR void *arg);
/* The one short operations supported by the lower half driver */
struct timespec;
struct oneshot_operations_s
{
CODE int (*max_delay)(FAR struct oneshot_s *lower, uint64_t *usec);
CODE int (*start)(FAR struct oneshot_dev_s *lower,
CODE int (*max_delay)(FAR struct oneshot_lowerhalf_s *lower,
FAR uint64_t *usec);
CODE int (*start)(FAR struct oneshot_lowerhalf_s *lower,
oneshot_callback_t callback, FAR void *arg,
FAR const struct timespec *ts);
CODE int (*cancel)(struct oneshot_dev_s *lower, FAR struct timespec *ts);
CODE int (*cancel)(struct oneshot_lowerhalf_s *lower,
FAR struct timespec *ts);
};
/* This structure describes the state of the oneshot timer driver */
/* This structure describes the state of the oneshot timer lower-half driver */
struct oneshot_dev_s
struct oneshot_lowerhalf_s
{
/* This is the part of the lower half driver that is visible to the upper-
* half client of the driver.
@ -194,7 +198,8 @@ extern "C"
*
****************************************************************************/
FAR struct oneshot_dev_s *oneshot_initialize(int chan, uint16_t resolution);
FAR struct oneshot_lowerhalf_s *oneshot_initialize(int chan,
uint16_t resolution);
#undef EXTERN
#ifdef __cplusplus