incubator-nuttx/drivers/timers/goldfish_timer.c

255 lines
8.3 KiB
C

/****************************************************************************
* drivers/timers/goldfish_timer.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/config.h>
#include <nuttx/arch.h>
#include <nuttx/irq.h>
#include <nuttx/kmalloc.h>
#include <nuttx/timers/oneshot.h>
#include <nuttx/spinlock.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef getreg32
#define getreg32(a) (*(volatile uint32_t *)(a))
#endif
#ifndef putreg32
#define putreg32(v,a) (*(volatile uint32_t *)(a) = (v))
#endif
#define GOLDFISH_TIMER_TIME_LOW 0x0 /* Get current time, then return low-order 32-bits. */
#define GOLDFISH_TIMER_TIME_HIGH 0x4 /* Return high 32-bits from previous TIME_LOW read. */
#define GOLDFISH_TIMER_ALARM_LOW 0x8 /* Set low 32-bit value of alarm, then arm it. */
#define GOLDFISH_TIMER_ALARM_HIGH 0xc /* Set high 32-bit value of alarm. */
#define GOLDFISH_TIMER_IRQ_ENABLED 0x10 /* Enable interrupts. */
#define GOLDFISH_TIMER_CLEAR_ALARM 0x14 /* Clear alarm. */
#define GOLDFISH_TIMER_ALARM_STATUS 0x18 /* Return 1 if alarm is armed, 0 if not. */
#define GOLDFISH_TIMER_CLEAR_INTERRUPT 0x1c /* Clear interrupt. */
/****************************************************************************
* 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 goldfish_timer_lowerhalf_s
{
struct oneshot_lowerhalf_s lh; /* Lower half operations */
oneshot_callback_t callback; /* Current user interrupt callback */
FAR void *arg; /* Argument passed to upper half callback */
uintptr_t base; /* Base address of registers */
spinlock_t lock; /* Lock for interrupt handling */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int goldfish_timer_maxdelay(FAR struct oneshot_lowerhalf_s *lower,
FAR struct timespec *ts);
static int goldfish_timer_start(FAR struct oneshot_lowerhalf_s *lower,
FAR oneshot_callback_t callback,
FAR void *arg,
FAR const struct timespec *ts);
static int goldfish_timer_cancel(FAR struct oneshot_lowerhalf_s *lower,
FAR struct timespec *ts);
static int goldfish_timer_current(FAR struct oneshot_lowerhalf_s *lower,
FAR struct timespec *ts);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct oneshot_operations_s g_goldfish_timer_ops =
{
.max_delay = goldfish_timer_maxdelay,
.start = goldfish_timer_start,
.cancel = goldfish_timer_cancel,
.current = goldfish_timer_current,
};
/****************************************************************************
* Private Functions
****************************************************************************/
static int goldfish_timer_maxdelay(FAR struct oneshot_lowerhalf_s *lower_,
FAR struct timespec *ts)
{
ts->tv_sec = UINT32_MAX;
ts->tv_nsec = UINT32_MAX;
return 0;
}
static int goldfish_timer_start(FAR struct oneshot_lowerhalf_s *lower_,
FAR oneshot_callback_t callback,
FAR void *arg,
FAR const struct timespec *ts)
{
FAR struct goldfish_timer_lowerhalf_s *lower =
(FAR struct goldfish_timer_lowerhalf_s *)lower_;
irqstate_t flags;
uint64_t nsec;
uint32_t l32;
uint32_t h32;
DEBUGASSERT(lower != NULL);
flags = spin_lock_irqsave(&lower->lock);
lower->callback = callback;
lower->arg = arg;
nsec = ts->tv_sec * 1000000000 + ts->tv_nsec;
l32 = getreg32(lower->base + GOLDFISH_TIMER_TIME_LOW);
h32 = getreg32(lower->base + GOLDFISH_TIMER_TIME_HIGH);
nsec += ((uint64_t)h32 << 32) | l32;
putreg32(1, lower->base + GOLDFISH_TIMER_IRQ_ENABLED);
putreg32(nsec >> 32, lower->base + GOLDFISH_TIMER_ALARM_HIGH);
putreg32(nsec, lower->base + GOLDFISH_TIMER_ALARM_LOW);
spin_unlock_irqrestore(&lower->lock, flags);
return 0;
}
static int goldfish_timer_cancel(FAR struct oneshot_lowerhalf_s *lower_,
FAR struct timespec *ts)
{
struct goldfish_timer_lowerhalf_s *lower =
(struct goldfish_timer_lowerhalf_s *)lower_;
irqstate_t flags;
DEBUGASSERT(lower != NULL);
flags = spin_lock_irqsave(&lower->lock);
lower->callback = NULL;
lower->arg = NULL;
putreg32(0, lower->base + GOLDFISH_TIMER_IRQ_ENABLED);
putreg32(1, lower->base + GOLDFISH_TIMER_CLEAR_ALARM);
spin_unlock_irqrestore(&lower->lock, flags);
return 0;
}
static int goldfish_timer_current(FAR struct oneshot_lowerhalf_s *lower_,
FAR struct timespec *ts)
{
FAR struct goldfish_timer_lowerhalf_s *lower =
(FAR struct goldfish_timer_lowerhalf_s *)lower_;
irqstate_t flags;
uint32_t l32;
uint32_t h32;
uint64_t nsec;
DEBUGASSERT(lower != NULL);
flags = spin_lock_irqsave(&lower->lock);
l32 = getreg32(lower->base + GOLDFISH_TIMER_TIME_LOW);
h32 = getreg32(lower->base + GOLDFISH_TIMER_TIME_HIGH);
nsec = ((uint64_t)h32 << 32) | l32;
ts->tv_sec = nsec / NSEC_PER_SEC;
ts->tv_nsec = nsec % NSEC_PER_SEC;
spin_unlock_irqrestore(&lower->lock, flags);
return 0;
}
static int goldfish_timer_interrupt(int irq,
FAR void *context,
FAR void *arg)
{
FAR struct goldfish_timer_lowerhalf_s *lower = arg;
oneshot_callback_t callback = NULL;
irqstate_t flags;
void *cbarg;
DEBUGASSERT(lower != NULL);
flags = spin_lock_irqsave(&lower->lock);
putreg32(1, lower->base + GOLDFISH_TIMER_CLEAR_ALARM);
if (lower->callback != NULL)
{
callback = lower->callback;
cbarg = lower->arg;
lower->callback = NULL;
lower->arg = NULL;
}
spin_unlock_irqrestore(&lower->lock, flags);
/* Then perform the callback */
if (callback)
{
callback(&lower->lh, cbarg);
}
return 0;
}
/****************************************************************************
* Public Functions
****************************************************************************/
FAR struct oneshot_lowerhalf_s *
goldfish_timer_initialize(uintptr_t base, int irq)
{
FAR struct goldfish_timer_lowerhalf_s *lower;
lower = kmm_zalloc(sizeof(*lower));
if (lower == NULL)
{
return NULL;
}
lower->lh.ops = &g_goldfish_timer_ops;
lower->base = base;
spin_lock_init(&lower->lock);
/* Enable timer, but disable interrupt */
irq_attach(irq, goldfish_timer_interrupt, lower);
up_enable_irq(irq);
putreg32(0, base + GOLDFISH_TIMER_IRQ_ENABLED);
return (struct oneshot_lowerhalf_s *)lower;
}