OpenModem/bertos/fs/fat.c

144 lines
3.8 KiB
C

/**
* \file
* <!--
* This file is part of BeRTOS.
*
* Bertos is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* As a special exception, you may use this file as part of a free software
* library without restriction. Specifically, if other files instantiate
* templates or use macros or inline functions from this file, or you compile
* this file and link it with other files to produce an executable, this
* file does not by itself cause the resulting executable to be covered by
* the GNU General Public License. This exception does not however
* invalidate any other reasons why the executable file might be covered by
* the GNU General Public License.
*
* Copyright 2009 Develer S.r.l. (http://www.develer.com/)
*
* -->
*
* \brief FatFS: kfile interface for FatFS module by ChaN.
*
*
* \author Luca Ottaviano <lottaviano@develer.com>
*
*/
#include "fat.h"
static size_t fatfile_read(struct KFile *_fd, void *buf, size_t size)
{
FatFile *fd = FATFILE_CAST(_fd);
UINT count;
fd->error_code = f_read(&fd->fat_file, buf, size, &count);
return count;
}
static size_t fatfile_write(struct KFile *_fd, const void *buf, size_t size)
{
FatFile *fd = FATFILE_CAST(_fd);
UINT count;
fd->error_code = f_write(&fd->fat_file, buf, size, &count);
return count;
}
static int fatfile_close(struct KFile *_fd)
{
FatFile *fd = FATFILE_CAST(_fd);
fd->error_code = f_close(&fd->fat_file);
if (fd->error_code)
return EOF;
else
return 0;
}
static kfile_off_t fatfile_seek(struct KFile *_fd, kfile_off_t offset, KSeekMode whence)
{
/* clip at start-of-file
* don't clip at end-of-file when in write mode
*/
FatFile *fd = FATFILE_CAST(_fd);
DWORD lseek_offset = 0;
switch (whence)
{
case KSM_SEEK_SET:
if (offset > 0)
lseek_offset = (DWORD) offset;
break;
case KSM_SEEK_CUR:
if (offset > 0)
lseek_offset = fd->fat_file.fptr + (DWORD) offset;
else
{
if (fd->fat_file.fptr > (DWORD) (-offset))
lseek_offset = fd->fat_file.fptr - (DWORD)(-offset);
}
break;
case KSM_SEEK_END:
if (offset > 0)
lseek_offset = fd->fat_file.fsize + (DWORD) offset;
else
{
if (fd->fat_file.fsize > (DWORD) (-offset))
lseek_offset = fd->fat_file.fsize + (DWORD) offset;
}
break;
}
fd->error_code = f_lseek(&fd->fat_file, lseek_offset);
if ((fd->error_code) || (fd->fat_file.fptr != lseek_offset))
return EOF;
else
/* TODO: this conversion may overflow */
return (kfile_off_t)fd->fat_file.fptr;
}
static int fatfile_flush(struct KFile *_fd)
{
FatFile *fd = FATFILE_CAST(_fd);
fd->error_code = f_sync(&fd->fat_file);
if (fd->error_code)
return EOF;
else
return 0;
}
static int fatfile_error(struct KFile *_fd)
{
FatFile *fd = FATFILE_CAST(_fd);
return (int)fd->error_code;
}
static void fatfile_clearerr(struct KFile *_fd)
{
FatFile *fd = FATFILE_CAST(_fd);
fd->error_code = FR_OK;
}
FRESULT fatfile_open(FatFile *file, const char *file_path, BYTE mode)
{
DB(file->fd._type = KFT_FATFILE);
file->fd.read = fatfile_read;
file->fd.write = fatfile_write;
file->fd.reopen = 0;
file->fd.close = fatfile_close;
file->fd.seek = fatfile_seek;
file->fd.flush = fatfile_flush;
file->fd.error = fatfile_error;
file->fd.clearerr = fatfile_clearerr;
return f_open(&file->fat_file, file_path, mode);
}