libmisc/devnull/devzero.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup libmisc_devnull Device Driver
0007  *
0008  * @brief Devzero
0009  */
0010
0011 /*
0012  * Copyright (c) 2011 embedded brains GmbH & Co. KG
0013  *
0014  * Redistribution and use in source and binary forms, with or without
0015  * modification, are permitted provided that the following conditions
0016  * are met:
0017  * 1. Redistributions of source code must retain the above copyright
0018  *    notice, this list of conditions and the following disclaimer.
0019  * 2. Redistributions in binary form must reproduce the above copyright
0020  *    notice, this list of conditions and the following disclaimer in the
0021  *    documentation and/or other materials provided with the distribution.
0022  *
0023  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0024  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0025  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0026  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0027  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0028  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0029  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0030  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0031  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0032  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0033  * POSSIBILITY OF SUCH DAMAGE.
0034  */
0035
0036 #ifdef HAVE_CONFIG_H
0037 #include "config.h"
0038 #endif
0039
0040 #include <rtems/devzero.h>
0041
0042 #include <string.h>
0043
0044 #include <rtems/libio.h>
0045
0046 rtems_device_driver dev_zero_initialize(
0047   rtems_device_major_number major,
0048   rtems_device_minor_number minor RTEMS_UNUSED,
0049   void *arg RTEMS_UNUSED
0050 )
0051 {
0052   return rtems_io_register_name(DEVZERO_DEVICE_NAME, major, 0);
0053 }
0054
0055 rtems_device_driver dev_zero_open(
0056   rtems_device_major_number major RTEMS_UNUSED,
0057   rtems_device_minor_number minor RTEMS_UNUSED,
0058   void *arg RTEMS_UNUSED
0059 )
0060 {
0061   return RTEMS_SUCCESSFUL;
0062 }
0063
0064 rtems_device_driver dev_zero_close(
0065   rtems_device_major_number major RTEMS_UNUSED,
0066   rtems_device_minor_number minor RTEMS_UNUSED,
0067   void *arg RTEMS_UNUSED
0068 )
0069 {
0070   return RTEMS_SUCCESSFUL;
0071 }
0072
0073 rtems_device_driver dev_zero_read(
0074   rtems_device_major_number major RTEMS_UNUSED,
0075   rtems_device_minor_number minor RTEMS_UNUSED,
0076   void *arg RTEMS_UNUSED
0077 )
0078 {
0079   rtems_libio_rw_args_t *rw = arg;
0080
0081   rw->bytes_moved = rw->count;
0082   memset(rw->buffer, 0, rw->count);
0083
0084   return RTEMS_SUCCESSFUL;
0085 }
0086
0087 rtems_device_driver dev_zero_write(
0088   rtems_device_major_number major RTEMS_UNUSED,
0089   rtems_device_minor_number minor RTEMS_UNUSED,
0090   void *arg
0091 )
0092 {
0093   rtems_libio_rw_args_t *rw = arg;
0094
0095   rw->bytes_moved = rw->count;
0096
0097   return RTEMS_SUCCESSFUL;
0098 }
0099
0100 rtems_device_driver dev_zero_control(
0101   rtems_device_major_number major RTEMS_UNUSED,
0102   rtems_device_minor_number minor RTEMS_UNUSED,
0103   void *arg RTEMS_UNUSED
0104 )
0105 {
0106   return RTEMS_IO_ERROR;
0107 }