nuttx-apps/graphics/ft80x/ft80x_ramdl.c

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/****************************************************************************
* apps/graphics/ft80x/ft80x_ramdl.c
*
* Copyright (C) 2018 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER OR CONTRIBUTORS 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/ioctl.h>
#include <stdint.h>
#include <unistd.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/lcd/ft80x.h>
#include "graphics/ft80x.h"
#include "ft80x.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: ft80x_ramdl_rewind
*
* Description:
* Reset to the start of RAM DL memory
*
* Input Parameters:
* fd - The file descriptor of the FT80x device. Opened by the caller
* with write access.
*
* Returned Value:
* Zero (OK) on success. A negated errno value on failure.
*
****************************************************************************/
int ft80x_ramdl_rewind(int fd)
{
off_t pos;
/* Reposition the VFSso that subsequent writes will be to the beginning of
* the hardware display list.
*/
pos = lseek(fd, 0, SEEK_SET);
if (pos < 0)
{
int errcode = errno;
ft80x_err("ERROR: lseek failed: %d\n", errcode);
return -errcode;
}
return OK;
}
/****************************************************************************
* Name: ft80x_ramdl_append
*
* Description:
* Append new display list data to RAM DL
*
* Input Parameters:
* fd - The file descriptor of the FT80x device. Opened by the caller
* with write access.
* data - A pointer to the start of the data to be written.
* len - The number of bytes to be written.
*
* Returned Value:
* Zero (OK) on success. A negated errno value on failure.
*
****************************************************************************/
int ft80x_ramdl_append(int fd, FAR const void *data, size_t len)
{
size_t nwritten;
DEBUGASSERT(data != NULL && ((uintptr_t)data & 3) == 0 &&
len > 0 && (len & 3) == 0);
/* Write the aligned data directly to the FT80x hardware display list.
*
* NOTE: We have inside knowledge that the write will complete in a
* single operation so that no piecewise writes will ever be necessary.
*/
nwritten = write(fd, data, len);
if (nwritten < 0)
{
int errcode = errno;
ft80x_err("ERROR: write failed: %d\n", errcode);
return -errcode;
}
DEBUGASSERT(nwritten == len);
return OK;
}