154 lines
4.0 KiB
C
154 lines
4.0 KiB
C
/****************************************************************************
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* drivers/ipcc/ipcc_poll.c
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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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 <nuttx/ipcc.h>
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#include <nuttx/kmalloc.h>
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#include <nuttx/semaphore.h>
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#include <assert.h>
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#include <debug.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <poll.h>
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#include <stdbool.h>
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#include <stdio.h>
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#include <sys/types.h>
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#include "ipcc_priv.h"
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: ipcc_poll
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*
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* Description:
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* Sets up or tears down poll for the driver associated with filep pointer
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*
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* Input Parameters:
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* filep - file associated with the driver instance
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* fds - The structure describing the events to be monitored, OR NULL if
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* this is a request to stop monitoring events.
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* setup - true: Setup up the poll; false: Teardown the poll
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*
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* Returned Value:
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* 0: Success; Negated errno on failure
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*
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* Assumptions/Limitations:
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*
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****************************************************************************/
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int ipcc_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 ipcc_driver_s *priv;
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FAR struct pollfd **slot;
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pollevent_t eventset;
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int ret;
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int i;
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/* Get our private data structure */
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priv = filep->f_inode->i_private;
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/* Get exclusive access to driver */
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if ((ret = nxmutex_lock(&priv->lock)) < 0)
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{
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/* nxmutex_lock() will return on signal, we did not start
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* any transfer yet, so we can safely return with error
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*/
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return ret;
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}
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/* Are we setting up the poll? Or tearing it down? */
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if (!setup)
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{
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/* We are tearing down the poll */
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slot = (FAR struct pollfd **)fds->priv;
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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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nxmutex_unlock(&priv->lock);
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return OK;
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}
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/* This is a request to set up the poll. Find an available slot
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* for the poll structure reference
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*/
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for (i = 0; i < CONFIG_IPCC_NPOLLWAITERS; i++)
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{
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/* Find an available slot */
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if (!priv->fds[i])
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{
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/* Bind the poll structure and this slot */
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priv->fds[i] = fds;
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fds->priv = &priv->fds[i];
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break;
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}
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}
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if (i >= CONFIG_IPCC_NPOLLWAITERS)
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{
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/* No free poll slot found */
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fds->priv = NULL;
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nxmutex_unlock(&priv->lock);
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return -EBUSY;
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}
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/* Should immediately notify on any of the requested events? */
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eventset = 0;
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#ifdef CONFIG_IPCC_BUFFERED
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if (circbuf_used(&priv->ipcc->rxbuf) > 0)
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{
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eventset |= POLLIN;
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}
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if (circbuf_space(&priv->ipcc->txbuf) > 0)
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{
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eventset |= POLLOUT;
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}
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#endif
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poll_notify(&fds, 1, eventset);
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nxmutex_unlock(&priv->lock);
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return OK;
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}
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