char_dev.c

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/*
 * Copyright (c) 2010 Lenka Trochtova
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <ipc/dev_iface.h>
#include <device/char_dev.h>
#include <errno.h>
#include <async.h>
#include <malloc.h>
#include <stdio.h>

static ssize_t char_dev_rw(int dev_phone, void *buf, size_t size, bool read)
{
        async_serialize_start();
        
        ipc_call_t answer;
        aid_t req;
        int ret;
        
        if (read) {
                req = async_send_1(dev_phone, DEV_IFACE_ID(CHAR_DEV_IFACE),
                    CHAR_DEV_READ, &answer);
                ret = async_data_read_start(dev_phone, buf, size);
        } else {
                req = async_send_1(dev_phone, DEV_IFACE_ID(CHAR_DEV_IFACE),
                    CHAR_DEV_WRITE, &answer);
                ret = async_data_write_start(dev_phone, buf, size);
        }
        
        sysarg_t rc;
        if (ret != EOK) {
                async_wait_for(req, &rc);
                async_serialize_end();
                if (rc == EOK)
                        return (ssize_t) ret;
                
                return (ssize_t) rc;
        }
        
        async_wait_for(req, &rc);
        async_serialize_end();
        
        ret = (int) rc;
        if (ret != EOK)
                return (ssize_t) ret;
        
        return (ssize_t) IPC_GET_ARG1(answer);
}

ssize_t char_dev_read(int dev_phone, void *buf, size_t size)
{
        return char_dev_rw(dev_phone, buf, size, true);
}

ssize_t char_dev_write(int dev_phone, void *buf, size_t size)
{
        return char_dev_rw(dev_phone, buf, size, false);
}

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