xserver-multidpi/hw/xfree86/common/xisb.c
2004-04-23 19:54:30 +00:00

177 lines
4.9 KiB
C

/*
* Copyright (c) 1997 Metro Link Incorporated
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
* OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* Except as contained in this notice, the name of the Metro Link shall not be
* used in advertising or otherwise to promote the sale, use or other dealings
* in this Software without prior written authorization from Metro Link.
*
*/
/* $XFree86: xc/programs/Xserver/hw/xfree86/common/xisb.c,v 1.5 2000/11/06 19:24:07 dawes Exp $ */
/*
X Input Serial Buffer routines for use in any XInput driver that accesses
a serial device.
*/
/*****************************************************************************
* Standard Headers
****************************************************************************/
#ifdef __UNIXOS2__
#define I_NEED_OS2_H
#endif
#include <misc.h>
#include <xf86.h>
#include <xf86Version.h>
#include <xf86_OSproc.h>
#include <xf86_OSlib.h>
#include <xf86Xinput.h>
#include "xisb.h"
/*****************************************************************************
* Local Headers
****************************************************************************/
/*****************************************************************************
* Variables without includable headers
****************************************************************************/
/*****************************************************************************
* Local Variables
****************************************************************************/
/*****************************************************************************
* Function Definitions
****************************************************************************/
XISBuffer *
XisbNew (int fd, xf86ssize_t size)
{
XISBuffer *b;
b = xalloc (sizeof (XISBuffer));
if (!b)
return (NULL);
b->buf = xalloc ((sizeof (unsigned char) * size));
if (!b->buf)
{
xfree (b);
return (NULL);
}
b->fd = fd;
b->trace = 0;
b->block_duration = 0;
b->current = 1; /* force it to be past the end to trigger initial read */
b->end = 0;
b->buffer_size = size;
return (b);
}
void
XisbFree (XISBuffer *b)
{
xfree (b->buf);
xfree (b);
}
int
XisbRead (XISBuffer *b)
{
int ret;
if (b->current >= b->end)
{
if (b->block_duration >= 0)
{
if (xf86WaitForInput (b->fd, b->block_duration) < 1)
return (-1);
}
else
{
/*
* automatically clear it so if XisbRead is called in a loop
* the next call will make sure there is data with select and
* thus prevent a blocking read
*/
b->block_duration = 0;
}
ret = xf86ReadSerial (b->fd, b->buf, b->buffer_size);
switch (ret)
{
case 0:
return (-1); /* timeout */
case -1:
return (-2); /* error */
default:
b->end = ret;
b->current = 0;
break;
}
}
if (b->trace)
ErrorF ("read 0x%02x (%c)\n", b->buf[b->current],
isprint(b->buf[b->current])?b->buf[b->current]:'.');
return (b->buf[b->current++]);
}
/* the only purpose of this function is to provide output tracing */
xf86ssize_t
XisbWrite (XISBuffer *b, unsigned char *msg, xf86ssize_t len)
{
if (b->trace)
{
int i = 0;
for (i = 0; i < len; i++)
ErrorF ("\t\twrote 0x%02x (%c)\n", msg[i], msg[i]);
}
return (xf86WriteSerial (b->fd, msg, len));
}
/* turn tracing of this buffer on (1) or off (0) */
void
XisbTrace (XISBuffer *b, int trace)
{
b->trace = trace;
}
/*
* specify a block_duration of -1 when you know the buffer's fd is ready to
* read. After a read, it is automatically set to 0 so that the next read
* will use check to select for data and prevent a block.
* It is the caller's responsibility to set the block_duration to -1 if it
* knows that there is data to read (because the main select loop triggered
* the read) and want's to avoid the unnecessary overhead of the select call
*
* a zero or positive block duration will cause the select to block for the
* give duration in usecs.
*/
void
XisbBlockDuration (XISBuffer *b, int block_duration)
{
b->block_duration = block_duration;
}