/**************************************************************************** * drivers/ipcc/ipcc_open.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 #include #include #include #include #include #include #include "ipcc_priv.h" /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: ipcc_open * * Description: * Opens driver for use by userspace applications. * * Input Parameters: * filep - pointer to a file structure to open. * * Returned Value: * OK on successfull open, or negated errno on failure. * * Assumptions/Limitations: * ****************************************************************************/ int ipcc_open(FAR struct file *filep) { FAR struct ipcc_driver_s *priv; int ret; /* Get our private data structure */ DEBUGASSERT(filep != NULL && filep->f_inode != NULL); priv = filep->f_inode->i_private; /* Get exclusive access to the IPCC driver state structure */ if ((ret = nxsem_wait(&priv->exclsem)) < 0) { return ret; } /* Increment the count of open references on the driver */ priv->crefs++; DEBUGASSERT(priv->crefs > 0); nxsem_post(&priv->exclsem); return OK; }