140 lines
4.5 KiB
C
140 lines
4.5 KiB
C
/****************************************************************************
|
|
* drivers/misc/dev_ascii.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 <poll.h>
|
|
|
|
#include <nuttx/fs/fs.h>
|
|
#include <nuttx/drivers/drivers.h>
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
#define PRINTABLE_FIRST 0x20
|
|
#define PRINTABLE_COUNT (0x7f - 0x20)
|
|
|
|
/****************************************************************************
|
|
* Private Function Prototypes
|
|
****************************************************************************/
|
|
|
|
static ssize_t devascii_read(FAR struct file *filep, FAR char *buffer,
|
|
size_t buflen);
|
|
static ssize_t devascii_write(FAR struct file *filep, FAR const char *buffer,
|
|
size_t buflen);
|
|
static int devascii_poll(FAR struct file *filep, FAR struct pollfd *fds,
|
|
bool setup);
|
|
|
|
/****************************************************************************
|
|
* Private Data
|
|
****************************************************************************/
|
|
|
|
static const struct file_operations g_devascii_fops =
|
|
{
|
|
NULL, /* open */
|
|
NULL, /* close */
|
|
devascii_read, /* read */
|
|
devascii_write, /* write */
|
|
NULL, /* seek */
|
|
NULL, /* ioctl */
|
|
NULL, /* mmap */
|
|
NULL, /* truncate */
|
|
devascii_poll /* poll */
|
|
};
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: devascii_read
|
|
****************************************************************************/
|
|
|
|
static ssize_t devascii_read(FAR struct file *filep, FAR char *buffer,
|
|
size_t len)
|
|
{
|
|
size_t i;
|
|
for (i = 0; i < len; i++)
|
|
{
|
|
buffer[i] = PRINTABLE_FIRST + (filep->f_pos + i) % PRINTABLE_COUNT;
|
|
|
|
/* Replace the space character with a newline */
|
|
|
|
if (buffer[i] == PRINTABLE_FIRST)
|
|
{
|
|
buffer[i] = '\n';
|
|
}
|
|
}
|
|
|
|
filep->f_pos += len;
|
|
return len;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: devascii_write
|
|
****************************************************************************/
|
|
|
|
static ssize_t devascii_write(FAR struct file *filep, FAR const char *buffer,
|
|
size_t len)
|
|
{
|
|
UNUSED(filep);
|
|
UNUSED(buffer);
|
|
|
|
return len;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: devascii_poll
|
|
****************************************************************************/
|
|
|
|
static int devascii_poll(FAR struct file *filep, FAR struct pollfd *fds,
|
|
bool setup)
|
|
{
|
|
UNUSED(filep);
|
|
|
|
if (setup)
|
|
{
|
|
poll_notify(&fds, 1, POLLIN | POLLOUT);
|
|
}
|
|
|
|
return OK;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: devascii_register
|
|
*
|
|
* Description:
|
|
* Register /dev/ascii
|
|
*
|
|
****************************************************************************/
|
|
|
|
void devascii_register(void)
|
|
{
|
|
register_driver("/dev/ascii", &g_devascii_fops, 0666, NULL);
|
|
}
|