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- /****************************************************************************
- * drivers/timers/oneshot.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 <sys/types.h>
- #include <stdint.h>
- #include <stdbool.h>
- #include <fcntl.h>
- #include <assert.h>
- #include <debug.h>
- #include <nuttx/kmalloc.h>
- #include <nuttx/signal.h>
- #include <nuttx/fs/fs.h>
- #include <nuttx/semaphore.h>
- #include <nuttx/timers/oneshot.h>
- #ifdef CONFIG_ONESHOT
- /****************************************************************************
- * Private Type Definitions
- ****************************************************************************/
- /* This structure describes the state of the upper half driver */
- struct oneshot_dev_s
- {
- FAR struct oneshot_lowerhalf_s *od_lower; /* Lower-half driver state */
- sem_t od_exclsem; /* Supports mutual exclusion */
- /* Oneshot timer expiration notification information */
- struct sigevent od_event; /* Signal info */
- struct sigwork_s od_work; /* Signal work */
- pid_t od_pid; /* PID to be notified */
- };
- /****************************************************************************
- * Private Function Prototypes
- ****************************************************************************/
- static int oneshot_open(FAR struct file *filep);
- static int oneshot_close(FAR struct file *filep);
- static ssize_t oneshot_read(FAR struct file *filep, FAR char *buffer,
- size_t buflen);
- static ssize_t oneshot_write(FAR struct file *filep, FAR const char *buffer,
- size_t buflen);
- static int oneshot_ioctl(FAR struct file *filep, int cmd,
- unsigned long arg);
- static void oneshot_callback(FAR struct oneshot_lowerhalf_s *lower,
- FAR void *arg);
- /****************************************************************************
- * Private Data
- ****************************************************************************/
- static const struct file_operations g_oneshot_ops =
- {
- oneshot_open, /* open */
- oneshot_close, /* close */
- oneshot_read, /* read */
- oneshot_write, /* write */
- NULL, /* seek */
- oneshot_ioctl, /* ioctl */
- NULL /* poll */
- #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
- , NULL /* unlink */
- #endif
- };
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: oneshot_callback
- ****************************************************************************/
- static void oneshot_callback(FAR struct oneshot_lowerhalf_s *lower,
- FAR void *arg)
- {
- FAR struct oneshot_dev_s *priv = (FAR struct oneshot_dev_s *)arg;
- DEBUGASSERT(priv != NULL);
- /* Signal the waiter.. if there is one */
- nxsig_notification(priv->od_pid, &priv->od_event,
- SI_QUEUE, &priv->od_work);
- }
- /****************************************************************************
- * Name: oneshot_open
- *
- * Description:
- * This function is called whenever the PWM device is opened.
- *
- ****************************************************************************/
- static int oneshot_open(FAR struct file *filep)
- {
- tmrinfo("Opening...\n");
- DEBUGASSERT(filep != NULL && filep->f_inode != NULL);
- return OK;
- }
- /****************************************************************************
- * Name: oneshot_close
- *
- * Description:
- * This function is called when the PWM device is closed.
- *
- ****************************************************************************/
- static int oneshot_close(FAR struct file *filep)
- {
- tmrinfo("Closing...\n");
- DEBUGASSERT(filep != NULL && filep->f_inode != NULL);
- return OK;
- }
- /****************************************************************************
- * Name: oneshot_read
- *
- * Description:
- * A dummy read method. This is provided only to satsify the VFS layer.
- *
- ****************************************************************************/
- static ssize_t oneshot_read(FAR struct file *filep, FAR char *buffer,
- size_t buflen)
- {
- /* Return zero -- usually meaning end-of-file */
- tmrinfo("buflen=%ld\n", (unsigned long)buflen);
- DEBUGASSERT(filep != NULL && filep->f_inode != NULL);
- return 0;
- }
- /****************************************************************************
- * Name: oneshot_write
- *
- * Description:
- * A dummy write method. This is provided only to satsify the VFS layer.
- *
- ****************************************************************************/
- static ssize_t oneshot_write(FAR struct file *filep, FAR const char *buffer,
- size_t buflen)
- {
- /* Return a failure */
- tmrinfo("buflen=%ld\n", (unsigned long)buflen);
- DEBUGASSERT(filep != NULL && filep->f_inode != NULL);
- return -EPERM;
- }
- /****************************************************************************
- * Name: oneshot_ioctl
- *
- * Description:
- * The standard ioctl method. This is where ALL of the PWM work is done.
- *
- ****************************************************************************/
- static int oneshot_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
- {
- FAR struct inode *inode;
- FAR struct oneshot_dev_s *priv;
- int ret;
- tmrinfo("cmd=%d arg=%08lx\n", cmd, (unsigned long)arg);
- DEBUGASSERT(filep != NULL && filep->f_inode != NULL);
- inode = filep->f_inode;
- priv = (FAR struct oneshot_dev_s *)inode->i_private;
- DEBUGASSERT(priv != NULL);
- /* Get exclusive access to the device structures */
- ret = nxsem_wait(&priv->od_exclsem);
- if (ret < 0)
- {
- return ret;
- }
- /* Handle oneshot timer ioctl commands */
- switch (cmd)
- {
- /* OSIOC_MAXDELAY - Return the maximum delay that can be supported
- * by this timer.
- * Argument: A reference to a struct timespec in
- * which the maximum time will be returned.
- */
- case OSIOC_MAXDELAY:
- {
- FAR struct timespec *ts = (FAR struct timespec *)((uintptr_t)arg);
- DEBUGASSERT(ts != NULL);
- ret = ONESHOT_MAX_DELAY(priv->od_lower, ts);
- }
- break;
- /* OSIOC_START - Start the oneshot timer
- * Argument: A reference to struct oneshot_start_s
- */
- case OSIOC_START:
- {
- FAR struct oneshot_start_s *start;
- pid_t pid;
- start = (FAR struct oneshot_start_s *)((uintptr_t)arg);
- DEBUGASSERT(start != NULL);
- /* Save signaling information */
- priv->od_event = start->event;
- pid = start->pid;
- if (pid == 0)
- {
- pid = getpid();
- }
- priv->od_pid = pid;
- /* Start the oneshot timer */
- ret = ONESHOT_START(priv->od_lower, oneshot_callback, priv,
- &start->ts);
- }
- break;
- /* OSIOC_CANCEL - Stop the timer
- * Argument: A reference to a struct timespec in
- * which the time remaining will be returned.
- */
- case OSIOC_CANCEL:
- {
- FAR struct timespec *ts = (FAR struct timespec *)((uintptr_t)arg);
- /* Cancel the oneshot timer */
- ret = ONESHOT_CANCEL(priv->od_lower, ts);
- nxsig_cancel_notification(&priv->od_work);
- }
- break;
- /* OSIOC_CURRENT - Get the current time
- * Argument: A reference to a struct timespec in
- * which the current time will be returned.
- */
- case OSIOC_CURRENT:
- {
- FAR struct timespec *ts = (FAR struct timespec *)((uintptr_t)arg);
- /* Get the current time */
- ret = ONESHOT_CURRENT(priv->od_lower, ts);
- }
- break;
- default:
- {
- tmrerr("ERROR: Unrecognized cmd: %d arg: %ld\n", cmd, arg);
- ret = -ENOTTY;
- }
- break;
- }
- nxsem_post(&priv->od_exclsem);
- return ret;
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: oneshot_register
- *
- * Description:
- * Register the oneshot device as 'devpath'
- *
- * Input Parameters:
- * devpath - The full path to the driver to register. E.g., "/dev/oneshot0"
- * lower - An instance of the lower half interface
- *
- * Returned Value:
- * Zero (OK) on success; a negated errno value on failure. The following
- * possible error values may be returned (most are returned by
- * register_driver()):
- *
- * EINVAL - 'path' is invalid for this operation
- * EEXIST - An inode already exists at 'path'
- * ENOMEM - Failed to allocate in-memory resources for the operation
- *
- ****************************************************************************/
- int oneshot_register(FAR const char *devname,
- FAR struct oneshot_lowerhalf_s *lower)
- {
- FAR struct oneshot_dev_s *priv;
- int ret;
- sninfo("devname=%s lower=%p\n", devname, lower);
- DEBUGASSERT(devname != NULL && lower != NULL);
- /* Allocate a new oneshot timer driver instance */
- priv = (FAR struct oneshot_dev_s *)
- kmm_zalloc(sizeof(struct oneshot_dev_s));
- if (!priv)
- {
- snerr("ERROR: Failed to allocate device structure\n");
- return -ENOMEM;
- }
- /* Initialize the new oneshot timer driver instance */
- priv->od_lower = lower;
- nxsem_init(&priv->od_exclsem, 0, 1);
- /* And register the oneshot timer driver */
- ret = register_driver(devname, &g_oneshot_ops, 0666, priv);
- if (ret < 0)
- {
- snerr("ERROR: register_driver failed: %d\n", ret);
- nxsem_destroy(&priv->od_exclsem);
- kmm_free(priv);
- }
- return ret;
- }
- #endif /* CONFIG_ONESHOT */
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