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arch/riscv: Add mtimer driver

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Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
This commit is contained in:
Xiang Xiao 2022-04-05 07:18:39 +08:00 committed by Petro Karashchenko
parent d4978bfba4
commit a90bdda1ae
2 changed files with 357 additions and 0 deletions
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306
arch/risc-v/src/common/riscv_mtimer.c Normal file
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/****************************************************************************
* arch/risc-v/src/common/riscv_mtimer.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/irq.h>
#include <nuttx/kmalloc.h>
#include "riscv_mtimer.h"
#include "riscv_internal.h"
/****************************************************************************
* Private Types
****************************************************************************/
/* This structure provides the private representation of the "lower-half"
* driver state structure. This structure must be cast-compatible with the
* oneshot_lowerhalf_s structure.
*/
struct riscv_mtimer_lowerhalf_s
{
struct oneshot_lowerhalf_s lower;
uintptr_t mtime;
uintptr_t mtimecmp;
uint64_t freq;
uint64_t alarm;
oneshot_callback_t callback;
void *arg;
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int riscv_mtimer_max_delay(struct oneshot_lowerhalf_s *lower,
struct timespec *ts);
static int riscv_mtimer_start(struct oneshot_lowerhalf_s *lower,
oneshot_callback_t callback, void *arg,
const struct timespec *ts);
static int riscv_mtimer_cancel(struct oneshot_lowerhalf_s *lower,
struct timespec *ts);
static int riscv_mtimer_current(struct oneshot_lowerhalf_s *lower,
struct timespec *ts);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct oneshot_operations_s g_riscv_mtimer_ops =
{
.max_delay = riscv_mtimer_max_delay,
.start = riscv_mtimer_start,
.cancel = riscv_mtimer_cancel,
.current = riscv_mtimer_current,
};
/****************************************************************************
* Private Functions
****************************************************************************/
static uint64_t riscv_mtimer_get_mtime(struct riscv_mtimer_lowerhalf_s *priv)
{
#ifdef CONFIG_ARCH_RV64
return getreg64(priv->mtime);
#else
uint32_t hi;
uint32_t lo;
do
{
hi = getreg32(priv->mtime + 4);
lo = getreg32(priv->mtime);
}
while (getreg32(priv->mtime + 4) != hi);
return ((uint64_t)hi << 32) | lo;
#endif
}
static void riscv_mtimer_set_mtimecmp(struct riscv_mtimer_lowerhalf_s *priv,
uint64_t value)
{
#ifdef CONFIG_ARCH_RV64
putreg64(value, priv->mtimecmp);
#else
putreg32(UINT32_MAX, priv->mtimecmp + 4);
putreg32(value, priv->mtimecmp);
putreg32(value >> 32, priv->mtimecmp + 4);
#endif
}
/****************************************************************************
* Name: riscv_mtimer_max_delay
*
* Description:
* Determine the maximum delay of the one-shot 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();
* ts The location in which to return the maximum delay.
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned
* on failure.
*
****************************************************************************/
static int riscv_mtimer_max_delay(struct oneshot_lowerhalf_s *lower,
struct timespec *ts)
{
ts->tv_sec = UINT32_MAX;
ts->tv_nsec = NSEC_PER_SEC - 1;
return 0;
}
/****************************************************************************
* Name: riscv_mtimer_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 riscv_mtimer_start(struct oneshot_lowerhalf_s *lower,
oneshot_callback_t callback, void *arg,
const struct timespec *ts)
{
struct riscv_mtimer_lowerhalf_s *priv =
(struct riscv_mtimer_lowerhalf_s *)lower;
uint64_t mtime = riscv_mtimer_get_mtime(priv);
priv->alarm = mtime + ts->tv_sec * priv->freq +
ts->tv_nsec * priv->freq / NSEC_PER_SEC;
if (priv->alarm < mtime)
{
priv->alarm = UINT64_MAX;
}
priv->callback = callback;
priv->arg = arg;
riscv_mtimer_set_mtimecmp(priv, priv->alarm);
return 0;
}
/****************************************************************************
* Name: riscv_mtimer_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 riscv_mtimer_cancel(struct oneshot_lowerhalf_s *lower,
struct timespec *ts)
{
struct riscv_mtimer_lowerhalf_s *priv =
(struct riscv_mtimer_lowerhalf_s *)lower;
uint64_t mtime;
riscv_mtimer_set_mtimecmp(priv, UINT64_MAX);
mtime = riscv_mtimer_get_mtime(priv);
if (priv->alarm > mtime)
{
uint64_t nsec = (priv->alarm - mtime) *
NSEC_PER_SEC / priv->freq;
ts->tv_sec = nsec / NSEC_PER_SEC;
ts->tv_nsec = nsec % NSEC_PER_SEC;
}
else
{
ts->tv_sec = 0;
ts->tv_nsec = 0;
}
priv->alarm = 0;
priv->callback = NULL;
priv->arg = NULL;
return 0;
}
/****************************************************************************
* Name: riscv_mtimer_current
*
* Description:
* Get the current time.
*
* 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 current time. A time of zero
* is returned for the initialization moment.
*
* Returned Value:
* Zero (OK) is returned on success, a negated errno value is returned on
* any failure.
*
****************************************************************************/
static int riscv_mtimer_current(struct oneshot_lowerhalf_s *lower,
struct timespec *ts)
{
struct riscv_mtimer_lowerhalf_s *priv =
(struct riscv_mtimer_lowerhalf_s *)lower;
uint64_t mtime = riscv_mtimer_get_mtime(priv);
uint64_t nsec = mtime * NSEC_PER_SEC / priv->freq;
ts->tv_sec = nsec / NSEC_PER_SEC;
ts->tv_nsec = nsec % NSEC_PER_SEC;
return 0;
}
static int riscv_mtimer_interrupt(int irq, void *context, void *arg)
{
struct riscv_mtimer_lowerhalf_s *priv = arg;
riscv_mtimer_set_mtimecmp(priv, UINT64_MAX);
if (priv->callback != NULL)
{
priv->callback(&priv->lower, priv->arg);
}
return 0;
}
/****************************************************************************
* Public Functions
****************************************************************************/
struct oneshot_lowerhalf_s *
riscv_mtimer_initialize(uintptr_t mtime, uintptr_t mtimecmp,
int irq, uint64_t freq)
{
struct riscv_mtimer_lowerhalf_s *priv;
priv = kmm_zalloc(sizeof(*priv));
if (priv != NULL)
{
priv->lower.ops = &g_riscv_mtimer_ops;
priv->mtime = mtime;
priv->mtimecmp = mtimecmp;
priv->freq = freq;
riscv_mtimer_set_mtimecmp(priv, UINT64_MAX);
irq_attach(irq, riscv_mtimer_interrupt, priv);
up_enable_irq(irq);
}
return (struct oneshot_lowerhalf_s *)priv;
}

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arch/risc-v/src/common/riscv_mtimer.h Normal file
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/****************************************************************************
* arch/risc-v/src/common/riscv_mtimer.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __ARCH_RISCV_SRC_COMMON_RISCV_MTIMER_H
#define __ARCH_RISCV_SRC_COMMON_RISCV_MTIMER_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/timers/oneshot.h>
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
struct oneshot_lowerhalf_s *
riscv_mtimer_initialize(uintptr_t mtime, uintptr_t mtimecmp,
int irq, uint64_t freq);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __ARCH_RISCV_SRC_COMMON_RISCV_MTIMER_H */