95 lines
2.8 KiB
C
95 lines
2.8 KiB
C
/****************************************************************************
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* drivers/ipcc/ipcc_close.c
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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 <errno.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_close
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*
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* Description:
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* Closes the driver device. If this is last reference and file has been
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* unlinked, we will also free resources allocated by ipcc_register()
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*
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* Input Parameters:
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* filep - pointer to a file structure to close.
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*
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* Returned Value:
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* OK on successfull close, or 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_close(FAR struct file *filep)
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{
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FAR struct ipcc_driver_s *priv;
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int ret;
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/* Get our private data structure */
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DEBUGASSERT(filep != NULL && filep->f_inode != NULL);
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priv = filep->f_inode->i_private;
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/* Get exclusive access to the IPCC driver state structure */
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if ((ret = nxsem_wait(&priv->exclsem)) < 0)
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{
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return ret;
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}
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/* Decrement the count of open references on the driver */
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DEBUGASSERT(priv->crefs > 0);
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priv->crefs--;
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if (priv->crefs <= 0 && priv->unlinked)
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{
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/* If count ref is zero and file has been unlinked, it
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* means nobody uses the driver and seems like nobody
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* wants to use it anymore, so free up resources.
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*/
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ipcc_cleanup(priv);
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return OK;
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}
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nxsem_post(&priv->exclsem);
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return OK;
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}
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