123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616 |
- /****************************************************************************
- * drivers/timers/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 <sys/types.h>
- #include <stdint.h>
- #include <stdbool.h>
- #include <string.h>
- #include <fcntl.h>
- #include <assert.h>
- #include <errno.h>
- #include <debug.h>
- #include <nuttx/irq.h>
- #include <nuttx/kmalloc.h>
- #include <nuttx/signal.h>
- #include <nuttx/fs/fs.h>
- #include <nuttx/semaphore.h>
- #include <nuttx/timers/timer.h>
- #ifdef CONFIG_TIMER
- /****************************************************************************
- * Private Type Definitions
- ****************************************************************************/
- /* This structure describes the state of the upper half driver */
- struct timer_upperhalf_s
- {
- sem_t exclsem; /* Supports mutual exclusion */
- uint8_t crefs; /* The number of times the device has been opened */
- FAR char *path; /* Registration path */
- /* The contained signal info */
- struct timer_notify_s notify;
- struct sigwork_s work;
- /* The contained lower-half driver */
- FAR struct timer_lowerhalf_s *lower;
- };
- /****************************************************************************
- * Private Function Prototypes
- ****************************************************************************/
- static bool timer_notifier(FAR uint32_t *next_interval_us, FAR void *arg);
- static int timer_open(FAR struct file *filep);
- static int timer_close(FAR struct file *filep);
- static ssize_t timer_read(FAR struct file *filep, FAR char *buffer,
- size_t buflen);
- static ssize_t timer_write(FAR struct file *filep, FAR const char *buffer,
- size_t buflen);
- static int timer_ioctl(FAR struct file *filep, int cmd,
- unsigned long arg);
- /****************************************************************************
- * Private Data
- ****************************************************************************/
- static const struct file_operations g_timerops =
- {
- timer_open, /* open */
- timer_close, /* close */
- timer_read, /* read */
- timer_write, /* write */
- NULL, /* seek */
- timer_ioctl, /* ioctl */
- NULL /* poll */
- #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
- , NULL /* unlink */
- #endif
- };
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: timer_notifier
- *
- * Description:
- * Notify the application via a signal when the timer interrupt occurs
- *
- * REVISIT: This function prototype is insufficient to support signaling
- *
- ****************************************************************************/
- static bool timer_notifier(FAR uint32_t *next_interval_us, FAR void *arg)
- {
- FAR struct timer_upperhalf_s *upper = (FAR struct timer_upperhalf_s *)arg;
- FAR struct timer_notify_s *notify = &upper->notify;
- DEBUGASSERT(upper != NULL);
- /* Signal the waiter.. if there is one */
- nxsig_notification(notify->pid, ¬ify->event,
- SI_QUEUE, &upper->work);
- return true;
- }
- /****************************************************************************
- * Name: timer_open
- *
- * Description:
- * This function is called whenever the timer device is opened.
- *
- ****************************************************************************/
- static int timer_open(FAR struct file *filep)
- {
- FAR struct inode *inode = filep->f_inode;
- FAR struct timer_upperhalf_s *upper = inode->i_private;
- uint8_t tmp;
- int ret;
- tmrinfo("crefs: %d\n", upper->crefs);
- /* Get exclusive access to the device structures */
- ret = nxsem_wait(&upper->exclsem);
- if (ret < 0)
- {
- goto errout;
- }
- /* Increment the count of references to the device. If this the first
- * time that the driver has been opened for this device, then initialize
- * the device.
- */
- tmp = upper->crefs + 1;
- if (tmp == 0)
- {
- /* More than 255 opens; uint8_t overflows to zero */
- ret = -EMFILE;
- goto errout_with_sem;
- }
- /* Save the new open count */
- upper->crefs = tmp;
- ret = OK;
- errout_with_sem:
- nxsem_post(&upper->exclsem);
- errout:
- return ret;
- }
- /****************************************************************************
- * Name: timer_close
- *
- * Description:
- * This function is called when the timer device is closed.
- *
- ****************************************************************************/
- static int timer_close(FAR struct file *filep)
- {
- FAR struct inode *inode = filep->f_inode;
- FAR struct timer_upperhalf_s *upper = inode->i_private;
- int ret;
- tmrinfo("crefs: %d\n", upper->crefs);
- /* Get exclusive access to the device structures */
- ret = nxsem_wait(&upper->exclsem);
- if (ret < 0)
- {
- return ret;
- }
- /* Decrement the references to the driver. If the reference count will
- * decrement to 0, then uninitialize the driver.
- */
- if (upper->crefs > 0)
- {
- upper->crefs--;
- }
- nxsem_post(&upper->exclsem);
- return OK;
- }
- /****************************************************************************
- * Name: timer_read
- *
- * Description:
- * A dummy read method. This is provided only to satisfy the VFS layer.
- *
- ****************************************************************************/
- static ssize_t timer_read(FAR struct file *filep, FAR char *buffer,
- size_t buflen)
- {
- /* Return zero -- usually meaning end-of-file */
- return 0;
- }
- /****************************************************************************
- * Name: timer_write
- *
- * Description:
- * A dummy write method. This is provided only to satisfy the VFS layer.
- *
- ****************************************************************************/
- static ssize_t timer_write(FAR struct file *filep, FAR const char *buffer,
- size_t buflen)
- {
- return 0;
- }
- /****************************************************************************
- * Name: timer_ioctl
- *
- * Description:
- * The standard ioctl method. This is where ALL of the timer work is
- * done.
- *
- ****************************************************************************/
- static int timer_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
- {
- FAR struct inode *inode = filep->f_inode;
- FAR struct timer_upperhalf_s *upper;
- FAR struct timer_lowerhalf_s *lower;
- int ret;
- tmrinfo("cmd: %d arg: %ld\n", cmd, arg);
- upper = inode->i_private;
- DEBUGASSERT(upper != NULL);
- lower = upper->lower;
- DEBUGASSERT(lower != NULL);
- /* Get exclusive access to the device structures */
- ret = nxsem_wait(&upper->exclsem);
- if (ret < 0)
- {
- return ret;
- }
- /* Handle built-in ioctl commands */
- switch (cmd)
- {
- /* cmd: TCIOC_START
- * Description: Start the timer
- * Argument: Ignored
- */
- case TCIOC_START:
- {
- /* Start the timer, resetting the time to the current timeout */
- if (lower->ops->start)
- {
- ret = lower->ops->start(lower);
- }
- else
- {
- ret = -ENOSYS;
- }
- }
- break;
- /* cmd: TCIOC_STOP
- * Description: Stop the timer
- * Argument: Ignored
- */
- case TCIOC_STOP:
- {
- /* Stop the timer */
- DEBUGASSERT(lower->ops->stop != NULL); /* Required */
- ret = lower->ops->stop(lower);
- nxsig_cancel_notification(&upper->work);
- }
- break;
- /* cmd: TCIOC_GETSTATUS
- * Description: Get the status of the timer.
- * Argument: A writeable pointer to struct timer_status_s.
- */
- case TCIOC_GETSTATUS:
- {
- FAR struct timer_status_s *status;
- /* Get the current timer status */
- if (lower->ops->getstatus) /* Optional */
- {
- status = (FAR struct timer_status_s *)((uintptr_t)arg);
- if (status)
- {
- ret = lower->ops->getstatus(lower, status);
- }
- else
- {
- ret = -EINVAL;
- }
- }
- else
- {
- ret = -ENOSYS;
- }
- }
- break;
- /* cmd: TCIOC_SETTIMEOUT
- * Description: Reset the timeout to this value
- * Argument: A 32-bit timeout value in microseconds.
- *
- * TODO: pass pointer to uint64 ns? Need to determine if these timers
- * are 16 or 32 bit...
- */
- case TCIOC_SETTIMEOUT:
- {
- /* Set a new timeout value (and reset the timer) */
- if (lower->ops->settimeout) /* Optional */
- {
- ret = lower->ops->settimeout(lower, (uint32_t)arg);
- }
- else
- {
- ret = -ENOSYS;
- }
- }
- break;
- /* cmd: TCIOC_NOTIFICATION
- * Description: Notify application via a signal when the timer expires.
- * Argument: signal information
- */
- case TCIOC_NOTIFICATION:
- {
- FAR struct timer_notify_s *notify =
- (FAR struct timer_notify_s *)((uintptr_t)arg);
- if (notify != NULL)
- {
- memcpy(&upper->notify, notify, sizeof(*notify));
- ret = timer_setcallback((FAR void *)upper,
- timer_notifier, upper);
- }
- else
- {
- ret = -EINVAL;
- }
- }
- break;
- /* cmd: TCIOC_MAXTIMEOUT
- * Description: Get the maximum supported timeout value
- * Argument: A 32-bit timeout value in microseconds.
- */
- case TCIOC_MAXTIMEOUT:
- {
- /* Get the maximum supported timeout value */
- if (lower->ops->maxtimeout) /* Optional */
- {
- ret = lower->ops->maxtimeout(lower, (uint32_t *)arg);
- }
- else
- {
- ret = -ENOSYS;
- }
- }
- break;
- /* Any unrecognized IOCTL commands might be platform-specific ioctl
- * commands
- */
- default:
- {
- tmrinfo("Forwarding unrecognized cmd: %d arg: %ld\n", cmd, arg);
- /* An ioctl commands that are not recognized by the "upper-half"
- * driver are forwarded to the lower half driver through this
- * method.
- */
- if (lower->ops->ioctl) /* Optional */
- {
- ret = lower->ops->ioctl(lower, cmd, arg);
- }
- else
- {
- ret = -ENOTTY;
- }
- }
- break;
- }
- nxsem_post(&upper->exclsem);
- return ret;
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: timer_register
- *
- * Description:
- * This function binds an instance of a "lower half" timer driver with the
- * "upper half" timer device and registers that device so that can be used
- * by application code.
- *
- * When this function is called, the "lower half" driver should be in the
- * disabled state (as if the stop() method had already been called).
- *
- * Input Parameters:
- * dev path - The full path to the driver to be registers in the NuttX
- * pseudo-filesystem. The recommended convention is to name all timer
- * drivers as "/dev/tc0", "/dev/tc1", etc. where the driver
- * path differs only in the "minor" number at the end of the device name.
- * lower - A pointer to an instance of lower half timer driver. This
- * instance is bound to the timer driver and must persists as long as
- * the driver persists.
- *
- * Returned Value:
- * On success, a non-NULL handle is returned to the caller. In the event
- * of any failure, a NULL value is returned.
- *
- ****************************************************************************/
- FAR void *timer_register(FAR const char *path,
- FAR struct timer_lowerhalf_s *lower)
- {
- FAR struct timer_upperhalf_s *upper;
- int ret;
- DEBUGASSERT(path && lower);
- tmrinfo("Entry: path=%s\n", path);
- /* Allocate the upper-half data structure */
- upper = (FAR struct timer_upperhalf_s *)
- kmm_zalloc(sizeof(struct timer_upperhalf_s));
- if (!upper)
- {
- tmrerr("ERROR: Upper half allocation failed\n");
- goto errout;
- }
- /* Initialize the timer device structure (it was already zeroed
- * by kmm_zalloc()).
- */
- upper->lower = lower;
- nxsem_init(&upper->exclsem, 0, 1);
- /* Copy the registration path */
- upper->path = strdup(path);
- if (!upper->path)
- {
- tmrerr("ERROR: Path allocation failed\n");
- goto errout_with_upper;
- }
- /* Register the timer device */
- ret = register_driver(path, &g_timerops, 0666, upper);
- if (ret < 0)
- {
- tmrerr("ERROR: register_driver failed: %d\n", ret);
- goto errout_with_path;
- }
- return (FAR void *)upper;
- errout_with_path:
- kmm_free(upper->path);
- errout_with_upper:
- nxsem_destroy(&upper->exclsem);
- kmm_free(upper);
- errout:
- return NULL;
- }
- /****************************************************************************
- * Name: timer_unregister
- *
- * Description:
- * This function can be called to disable and unregister the timer
- * device driver.
- *
- * Input Parameters:
- * handle - This is the handle that was returned by timer_register()
- *
- * Returned Value:
- * None
- *
- ****************************************************************************/
- void timer_unregister(FAR void *handle)
- {
- FAR struct timer_upperhalf_s *upper;
- FAR struct timer_lowerhalf_s *lower;
- /* Recover the pointer to the upper-half driver state */
- upper = (FAR struct timer_upperhalf_s *)handle;
- DEBUGASSERT(upper != NULL && upper->lower != NULL);
- lower = upper->lower;
- tmrinfo("Unregistering: %s\n", upper->path);
- /* Disable the timer */
- DEBUGASSERT(lower->ops->stop); /* Required */
- lower->ops->stop(lower);
- nxsig_cancel_notification(&upper->work);
- /* Unregister the timer device */
- unregister_driver(upper->path);
- /* Then free all of the driver resources */
- nxsem_destroy(&upper->exclsem);
- kmm_free(upper->path);
- kmm_free(upper);
- }
- /****************************************************************************
- * Name: timer_setcallback
- *
- * Description:
- * This function can be called to add a callback into driver-related code
- * to handle timer expirations. This is a strictly OS internal interface
- * and may NOT be used by application code.
- *
- * Input Parameters:
- * handle - This is the handle that was returned by timer_register()
- * callback - The new timer interrupt callback
- * arg - Argument to be provided with the callback
- *
- * Returned Value:
- * Zero (OK), if the callback was successfully set, or -ENOSYS if the lower
- * half driver does not support the operation.
- *
- ****************************************************************************/
- int timer_setcallback(FAR void *handle, tccb_t callback, FAR void *arg)
- {
- FAR struct timer_upperhalf_s *upper;
- FAR struct timer_lowerhalf_s *lower;
- /* Recover the pointer to the upper-half driver state */
- upper = (FAR struct timer_upperhalf_s *)handle;
- DEBUGASSERT(upper != NULL && upper->lower != NULL);
- lower = upper->lower;
- DEBUGASSERT(lower->ops != NULL);
- /* Check if the lower half driver supports the setcallback method */
- if (lower->ops->setcallback != NULL) /* Optional */
- {
- /* Yes.. Defer the handler attachment to the lower half driver */
- lower->ops->setcallback(lower, callback, arg);
- return OK;
- }
- return -ENOSYS;
- }
- #endif /* CONFIG_TIMER */
|