/****************************************************************************
 * drivers/pipes/fifo.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 <sys/types.h>
#include <sys/stat.h>
#include <stdint.h>
#include <errno.h>
#include <fs/driver.h>
#include "pipe_common.h"

#if CONFIG_DEV_FIFO_SIZE > 0

/****************************************************************************
 * Private Data
 ****************************************************************************/

static ssize_t fifo_map(struct file* filep, LosVmMapRegion *region)
{
  PRINTK("%s %d, mmap is not support\n", __FUNCTION__, __LINE__);
  return 0;
}

static const struct file_operations_vfs fifo_fops =
{
  .open = pipecommon_open,      /* open */
  .close = pipecommon_close,    /* close */
  .read = pipecommon_read,      /* read */
  .write = pipecommon_write,    /* write */
  .seek = NULL,                 /* seek */
  .ioctl = NULL,                /* ioctl */
  .mmap = fifo_map,             /* mmap */
  .poll = NULL,                 /* poll */
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
  .unlink = pipecommon_unlink,  /* unlink */
#endif
};

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: mkfifo2
 *
 * Description:
 *   mkfifo() makes a FIFO device driver file with name 'pathname.'  Unlike
 *   Linux, a NuttX FIFO is not a special file type but simply a device
 *   driver instance.  'mode' specifies the FIFO's permissions.
 *
 *   Once the FIFO has been created by mkfifo(), any thread can open it for
 *   reading or writing, in the same way as an ordinary file. However, it
 *   must have been opened from both reading and writing before input or
 *   output can be performed.  This FIFO implementation will block all
 *   attempts to open a FIFO read-only until at least one thread has opened
 *   the FIFO for  writing.
 *
 *   If all threads that write to the FIFO have closed, subsequent calls to
 *   read() on the FIFO will return 0 (end-of-file).
 *
 *   NOTE: mkfifo2 is a special, non-standard, NuttX-only interface.  Since
 *   the NuttX FIFOs are based in in-memory, circular buffers, the ability
 *   to control the size of those buffers is critical for system tuning.
 *
 * Input Parameters:
 *   pathname - The full path to the FIFO instance to attach to or to create
 *     (if not already created).
 *   mode - Ignored for now
 *   bufsize - The size of the in-memory, circular buffer in bytes.
 *
 * Returned Value:
 *   0 is returned on success; otherwise, -1 is returned with errno set
 *   appropriately.
 *
 ****************************************************************************/

int mkfifo(const char *pathname, mode_t mode)
{
  struct pipe_dev_s *dev = NULL;
  int ret;
  size_t bufsize = 1024;

  if (mode > 0777)
    {
      return -EINVAL;
    }

  if (pathname == NULL)
    {
      return -EINVAL;
    }

  if (strlen(pathname) > PATH_MAX)
    {
      return -EINVAL;
    }

  /* Allocate and initialize a new device structure instance */

  dev = pipecommon_allocdev(bufsize, pathname);
  if (!dev)
    {
      return -ENOMEM;
    }

  ret = register_driver(pathname, &fifo_fops, mode, (void *)dev);
  if (ret != 0)
    {
      pipecommon_freedev(dev);
    }

  return ret;
}

#endif /* CONFIG_DEV_FIFO_SIZE > 0 */