472 lines
13 KiB
C
472 lines
13 KiB
C
/****************************************************************************
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* drivers/analog/comp.c
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*
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* Copyright (C) 2017 Gregory Nutt. All rights reserved.
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* Author: Mateusz Szafoni <raiden00@railab.me>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <sys/types.h>
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#include <stdint.h>
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#include <unistd.h>
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#include <semaphore.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <debug.h>
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#include <poll.h>
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#include <nuttx/arch.h>
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#include <nuttx/semaphore.h>
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#include <nuttx/fs/fs.h>
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#include <nuttx/analog/comp.h>
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#include <nuttx/irq.h>
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/****************************************************************************
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* Private Function Prototypes
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****************************************************************************/
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static int comp_open(FAR struct file *filep);
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static int comp_close(FAR struct file *filep);
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static ssize_t comp_read(FAR struct file *filep, FAR char *buffer,
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size_t buflen);
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static int comp_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
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#ifndef CONFIG_DISABLE_POLL
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static int comp_poll(FAR struct file *filep, FAR struct pollfd *fds,
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bool setup);
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static int comp_notify(FAR struct comp_dev_s *dev, uint8_t val);
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#endif
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/****************************************************************************
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* Private Data
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****************************************************************************/
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static const struct file_operations comp_fops =
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{
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comp_open, /* open */
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comp_close, /* close */
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comp_read, /* read */
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NULL, /* write */
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NULL, /* seek */
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comp_ioctl /* ioctl */
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#ifndef CONFIG_DISABLE_POLL
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, comp_poll /* poll */
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#endif
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#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
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, NULL /* unlink */
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#endif
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};
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#ifndef CONFIG_DISABLE_POLL
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static const struct comp_callback_s g_comp_callback =
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{
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comp_notify /* au_notify */
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};
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#endif
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: comp_pollnotify
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*
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* Description:
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* This function is called to notificy any waiters of poll-reated events.
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*
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****************************************************************************/
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#ifndef CONFIG_DISABLE_POLL
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static void comp_pollnotify(FAR struct comp_dev_s *dev,
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pollevent_t eventset)
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{
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int i;
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if (eventset & POLLERR)
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{
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eventset &= ~(POLLOUT | POLLIN);
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}
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for (i = 0; i < CONFIG_DEV_COMP_NPOLLWAITERS; i++)
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{
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FAR struct pollfd *fds = dev->d_fds[i];
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if (fds)
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{
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fds->revents |= eventset & (fds->events | POLLERR | POLLHUP);
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if ((fds->revents & (POLLOUT | POLLHUP)) == (POLLOUT | POLLHUP))
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{
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/* POLLOUT and POLLHUP are mutually exclusive. */
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fds->revents &= ~POLLOUT;
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}
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if (fds->revents != 0)
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{
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ainfo("Report events: %02x\n", fds->revents);
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nxsem_post(fds->sem);
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}
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}
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}
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}
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#endif
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/****************************************************************************
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* Name: comp_semtake
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****************************************************************************/
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#ifndef CONFIG_DISABLE_POLL
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static void comp_semtake(FAR sem_t *sem)
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{
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int ret;
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do
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{
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/* Take the semaphore (perhaps waiting) */
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ret = nxsem_wait(sem);
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/* The only case that an error should occur here is if the wait was
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* awakened by a signal.
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*/
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DEBUGASSERT(ret == OK || ret == -EINTR);
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}
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while (ret == -EINTR);
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}
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#endif
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/****************************************************************************
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* Name: comp_poll
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****************************************************************************/
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#ifndef CONFIG_DISABLE_POLL
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static int comp_poll(FAR struct file *filep, FAR struct pollfd *fds,
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bool setup)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct comp_dev_s *dev = inode->i_private;
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int ret = OK;
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int i;
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DEBUGASSERT(dev && fds);
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/* Are we setting up the poll? Or tearing it down? */
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comp_semtake(&dev->ad_sem);
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if (setup)
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{
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/* This is a request to set up the poll. Find an available
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* slot for the poll structure reference
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*/
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for (i = 0; i < CONFIG_DEV_COMP_NPOLLWAITERS; i++)
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{
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/* Find an available slot */
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if (!dev->d_fds[i])
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{
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/* Bind the poll structure and this slot */
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dev->d_fds[i] = fds;
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fds->priv = &dev->d_fds[i];
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break;
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}
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}
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if (i >= CONFIG_DEV_COMP_NPOLLWAITERS)
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{
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fds->priv = NULL;
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ret = -EBUSY;
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goto errout;
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}
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}
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else
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{
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/* This is a request to tear down the poll. */
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FAR struct pollfd **slot = (FAR struct pollfd **)fds->priv;
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#ifdef CONFIG_DEBUG_FEATURES
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if (!slot)
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{
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ret = -EIO;
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goto errout;
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}
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#endif
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/* Remove all memory of the poll setup */
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*slot = NULL;
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fds->priv = NULL;
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}
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errout:
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nxsem_post(&dev->ad_sem);
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return ret;
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}
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#endif
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/****************************************************************************
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* Name: comp_notify
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*
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* Description:
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* This function is called from the lower half driver to notify
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* the change of the comparator output.
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*
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****************************************************************************/
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#ifndef CONFIG_DISABLE_POLL
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static int comp_notify(FAR struct comp_dev_s *dev, uint8_t val)
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{
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/* TODO: store values in FIFO? */
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dev->val = val;
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comp_pollnotify(dev, POLLIN);
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nxsem_post(&dev->ad_readsem);
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return 0;
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}
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#endif
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/****************************************************************************
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* Name: comp_open
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*
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* Description:
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* This function is called whenever the COMP device is opened.
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*
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****************************************************************************/
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static int comp_open(FAR struct file *filep)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct comp_dev_s *dev = inode->i_private;
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uint8_t tmp;
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int ret;
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/* If the port is the middle of closing, wait until the close is finished */
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ret = nxsem_wait(&dev->ad_sem);
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if (ret >= 0)
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{
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/* Increment the count of references to the device. If this the first
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* time that the driver has been opened for this device, then initialize
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* the device.
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*/
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tmp = dev->ad_ocount + 1;
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if (tmp == 0)
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{
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/* More than 255 opens; uint8_t overflows to zero */
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ret = -EMFILE;
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}
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else
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{
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/* Check if this is the first time that the driver has been opened. */
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if (tmp == 1)
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{
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/* Yes.. perform one time hardware initialization. */
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irqstate_t flags = enter_critical_section();
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ret = dev->ad_ops->ao_setup(dev);
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if (ret == OK)
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{
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/* Save the new open count on success */
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dev->ad_ocount = tmp;
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}
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leave_critical_section(flags);
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}
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}
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nxsem_post(&dev->ad_sem);
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}
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return ret;
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}
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/****************************************************************************
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* Name: comp_close
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*
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* Description:
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* This routine is called when the COMP device is closed.
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* It waits for the last remaining data to be sent.
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*
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****************************************************************************/
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static int comp_close(FAR struct file *filep)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct comp_dev_s *dev = inode->i_private;
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irqstate_t flags;
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int ret;
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ret = nxsem_wait(&dev->ad_sem);
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if (ret >= 0)
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{
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/* Decrement the references to the driver. If the reference count will
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* decrement to 0, then uninitialize the driver.
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*/
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if (dev->ad_ocount > 1)
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{
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dev->ad_ocount--;
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nxsem_post(&dev->ad_sem);
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}
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else
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{
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/* There are no more references to the port */
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dev->ad_ocount = 0;
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/* Free the IRQ and disable the COMP device */
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flags = enter_critical_section(); /* Disable interrupts */
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dev->ad_ops->ao_shutdown(dev); /* Disable the COMP */
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leave_critical_section(flags);
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nxsem_post(&dev->ad_sem);
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}
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}
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return ret;
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}
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/****************************************************************************
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* Name: comp_read
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****************************************************************************/
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static ssize_t comp_read(FAR struct file *filep, FAR char *buffer, size_t buflen)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct comp_dev_s *dev = inode->i_private;
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int ret;
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/* If non-blocking read, read the value immediately and return. */
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#ifndef CONFIG_DISABLE_POLL
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if (filep->f_oflags & O_NONBLOCK)
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#endif
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{
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ret = dev->ad_ops->ao_read(dev);
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buffer[0] = (uint8_t)ret;
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return 1;
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}
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#ifndef CONFIG_DISABLE_POLL
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ret = nxsem_wait(&dev->ad_readsem);
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if (ret < 0)
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{
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aerr("nxsem_wait() failed: %d\n", ret);
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return ret;
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}
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buffer[0] = dev->val;
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return 1;
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#endif
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}
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/****************************************************************************
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* Name: comp_ioctl
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****************************************************************************/
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static int comp_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct comp_dev_s *dev = inode->i_private;
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int ret;
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ret = dev->ad_ops->ao_ioctl(dev, cmd, arg);
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return ret;
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: comp_register
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****************************************************************************/
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int comp_register(FAR const char *path, FAR struct comp_dev_s *dev)
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{
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int ret;
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/* Initialize the COMP device structure */
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dev->ad_ocount = 0;
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/* Initialize semaphores */
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nxsem_init(&dev->ad_sem, 0, 1);
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(void)nxsem_setprotocol(&dev->ad_sem, SEM_PRIO_NONE);
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nxsem_init(&dev->ad_readsem, 0, 0);
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(void)nxsem_setprotocol(&dev->ad_readsem, SEM_PRIO_NONE);
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/* Bind the upper-half callbacks to the lower half COMP driver */
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DEBUGASSERT(dev->ad_ops != NULL);
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#ifndef CONFIG_DISABLE_POLL
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if (dev->ad_ops->ao_bind != NULL)
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{
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ret = dev->ad_ops->ao_bind(dev, &g_comp_callback);
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if (ret < 0)
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{
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aerr("ERROR: Failed to bind callbacks: %d\n", ret);
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return ret;
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}
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}
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#endif
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/* Register the COMP character driver */
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ret = register_driver(path, &comp_fops, 0444, dev);
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if (ret < 0)
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{
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nxsem_destroy(&dev->ad_sem);
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}
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return ret;
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}
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