| 1 |
2 |
alfik |
/******************************************************************************
|
| 2 |
|
|
* *
|
| 3 |
|
|
* License Agreement *
|
| 4 |
|
|
* *
|
| 5 |
|
|
* Copyright (c) 2004-2005 Altera Corporation, San Jose, California, USA. *
|
| 6 |
|
|
* All rights reserved. *
|
| 7 |
|
|
* *
|
| 8 |
|
|
* Permission is hereby granted, free of charge, to any person obtaining a *
|
| 9 |
|
|
* copy of this software and associated documentation files (the "Software"), *
|
| 10 |
|
|
* to deal in the Software without restriction, including without limitation *
|
| 11 |
|
|
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
|
| 12 |
|
|
* and/or sell copies of the Software, and to permit persons to whom the *
|
| 13 |
|
|
* Software is furnished to do so, subject to the following conditions: *
|
| 14 |
|
|
* *
|
| 15 |
|
|
* The above copyright notice and this permission notice shall be included in *
|
| 16 |
|
|
* all copies or substantial portions of the Software. *
|
| 17 |
|
|
* *
|
| 18 |
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
|
| 19 |
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
|
| 20 |
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE *
|
| 21 |
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER *
|
| 22 |
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING *
|
| 23 |
|
|
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER *
|
| 24 |
|
|
* DEALINGS IN THE SOFTWARE. *
|
| 25 |
|
|
* *
|
| 26 |
|
|
* This agreement shall be governed in all respects by the laws of the State *
|
| 27 |
|
|
* of California and by the laws of the United States of America. *
|
| 28 |
|
|
* *
|
| 29 |
|
|
* Altera does not recommend, suggest or require that this reference design *
|
| 30 |
|
|
* file be used in conjunction or combination with any other product. *
|
| 31 |
|
|
******************************************************************************/
|
| 32 |
|
|
|
| 33 |
|
|
#include <unistd.h>
|
| 34 |
|
|
|
| 35 |
|
|
#include "sys/alt_errno.h"
|
| 36 |
|
|
#include "sys/alt_warning.h"
|
| 37 |
|
|
#include "priv/alt_file.h"
|
| 38 |
|
|
#include "os/alt_syscall.h"
|
| 39 |
|
|
|
| 40 |
|
|
#ifdef ALT_USE_DIRECT_DRIVERS
|
| 41 |
|
|
|
| 42 |
|
|
off_t ALT_LSEEK (int file, off_t ptr, int dir)
|
| 43 |
|
|
{
|
| 44 |
|
|
/* Generate a link time warning, should this function ever be called. */
|
| 45 |
|
|
|
| 46 |
|
|
ALT_STUB_WARNING(lseek);
|
| 47 |
|
|
|
| 48 |
|
|
/* Indicate an error */
|
| 49 |
|
|
|
| 50 |
|
|
ALT_ERRNO = ENOSYS;
|
| 51 |
|
|
return -1;
|
| 52 |
|
|
}
|
| 53 |
|
|
|
| 54 |
|
|
#else /* !ALT_USE_DIRECT_DRIVERS */
|
| 55 |
|
|
|
| 56 |
|
|
/*
|
| 57 |
|
|
* lseek() can be called to move the read/write pointer associated with the
|
| 58 |
|
|
* file descriptor "file". This function simply vectors the call to the lseek()
|
| 59 |
|
|
* function provided by the driver associated with the file descriptor.
|
| 60 |
|
|
*
|
| 61 |
|
|
* If the driver does not provide an implementation of lseek() an error is
|
| 62 |
|
|
* indicated.
|
| 63 |
|
|
*
|
| 64 |
|
|
* lseek() corresponds to the standard lseek() function.
|
| 65 |
|
|
*
|
| 66 |
|
|
* ALT_LSEEK is mapped onto the lseek() system call in alt_syscall.h
|
| 67 |
|
|
*
|
| 68 |
|
|
*/
|
| 69 |
|
|
|
| 70 |
|
|
off_t ALT_LSEEK (int file, off_t ptr, int dir)
|
| 71 |
|
|
{
|
| 72 |
|
|
alt_fd* fd;
|
| 73 |
|
|
off_t rc = 0;
|
| 74 |
|
|
|
| 75 |
|
|
/*
|
| 76 |
|
|
* A common error case is that when the file descriptor was created, the call
|
| 77 |
|
|
* to open() failed resulting in a negative file descriptor. This is trapped
|
| 78 |
|
|
* below so that we don't try and process an invalid file descriptor.
|
| 79 |
|
|
*/
|
| 80 |
|
|
|
| 81 |
|
|
fd = (file < 0) ? NULL : &alt_fd_list[file];
|
| 82 |
|
|
|
| 83 |
|
|
if (fd)
|
| 84 |
|
|
{
|
| 85 |
|
|
/*
|
| 86 |
|
|
* If the device driver provides an implementation of the lseek() function,
|
| 87 |
|
|
* then call that to process the request.
|
| 88 |
|
|
*/
|
| 89 |
|
|
|
| 90 |
|
|
if (fd->dev->lseek)
|
| 91 |
|
|
{
|
| 92 |
|
|
rc = fd->dev->lseek(fd, ptr, dir);
|
| 93 |
|
|
}
|
| 94 |
|
|
/*
|
| 95 |
|
|
* Otherwise return an error.
|
| 96 |
|
|
*/
|
| 97 |
|
|
|
| 98 |
|
|
else
|
| 99 |
|
|
{
|
| 100 |
|
|
rc = -ENOTSUP;
|
| 101 |
|
|
}
|
| 102 |
|
|
}
|
| 103 |
|
|
else
|
| 104 |
|
|
{
|
| 105 |
|
|
rc = -EBADFD;
|
| 106 |
|
|
}
|
| 107 |
|
|
|
| 108 |
|
|
if (rc < 0)
|
| 109 |
|
|
{
|
| 110 |
|
|
ALT_ERRNO = -rc;
|
| 111 |
|
|
rc = -1;
|
| 112 |
|
|
}
|
| 113 |
|
|
|
| 114 |
|
|
return rc;
|
| 115 |
|
|
}
|
| 116 |
|
|
|
| 117 |
|
|
#endif /* ALT_USE_DIRECT_DRIVERS */
|
