incubator-nuttx/net/can/can_poll.c

90 lines
2.7 KiB
C

/****************************************************************************
* net/can/can_poll.c
* Poll for the availability of packet TX data
*
* 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>
#if defined(CONFIG_NET) && defined(CONFIG_NET_CAN)
#include <assert.h>
#include <debug.h>
#include <nuttx/net/netconfig.h>
#include <nuttx/net/netdev.h>
#include "devif/devif.h"
#include "can/can.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: can_poll
*
* Description:
* Poll a packet "connection" structure for availability of TX data
*
* Input Parameters:
* dev - The device driver structure to use in the send operation
* conn - The packet "connection" to poll for TX data
*
* Returned Value:
* None
*
* Assumptions:
* The network is locked.
* dev is not NULL.
* conn is not NULL.
* The connection (conn) is bound to the polling device (dev).
*
****************************************************************************/
void can_poll(FAR struct net_driver_s *dev, FAR struct can_conn_s *conn)
{
DEBUGASSERT(dev != NULL && conn != NULL && dev == conn->dev);
/* Setup for the application callback */
dev->d_appdata = IPBUF(0);
dev->d_len = 0;
dev->d_sndlen = 0;
/* Perform the application callback */
can_callback(dev, conn, CAN_POLL);
/* Check if the application has data to send */
if (dev->d_sndlen > 0)
{
return;
}
/* Make sure that d_len is zero meaning that there is nothing to be sent */
dev->d_len = 0;
}
#endif /* CONFIG_NET && CONFIG_NET_CAN */