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/*
* libraw1394 - library for raw access to the 1394 bus with the Linux subsystem.
*
* Copyright (C) 1999,2000,2001,2002 Andreas Bombe
* new ISO API by Dan Maas
*
* This library is licensed under the GNU Lesser General Public License (LGPL),
* version 2.1 or later. See the file COPYING.LIB in the distribution for
* details.
*/
#include <config.h>
#include <errno.h>
#include <unistd.h>
#include <byteswap.h>
#include "raw1394.h"
#include "kernel-raw1394.h"
#include "raw1394_private.h"
/* legacy ISO API - emulated for backwards compatibility
*
* (this code emulates the behavior of the old API using
* the new "rawiso" API)
*/
static enum raw1394_iso_disposition legacy_iso_handler(raw1394handle_t handle,
unsigned char *data,
unsigned int len,
unsigned char channel,
unsigned char tag,
unsigned char sy,
unsigned int cycle,
unsigned int dropped);
/**
* raw1394_set_iso_handler - set isochronous packet handler
* @new_h: pointer to new handler
*
* Sets the handler to be called when an isochronous packet is received to
* @new_h and returns the old handler. The default handler does nothing.
*
* In order to actually get iso packet events, receiving on a specific channel
* first has to be enabled with raw1394_start_iso_rcv() and can be stopped again
* with raw1394_stop_iso_rcv().
**/
iso_handler_t raw1394_set_iso_handler(struct raw1394_handle *handle,
unsigned int channel, iso_handler_t new)
{
if (channel >= 64)
goto err;
/* is this channel already being used? */
if (handle->iso_handler[channel] != NULL)
goto err;
/* start up the recv context, if necessary */
if (!handle->legacy_iso_active) {
/* hmm, is there a good average value for max_packet_size? */
if (raw1394_iso_multichannel_recv_init(handle,
legacy_iso_handler,
1024,
500,
-1))
goto err;
if (raw1394_iso_recv_start(handle, -1)) {
raw1394_iso_shutdown(handle);
goto err;
}
handle->legacy_iso_active = 1;
}
if (new == NULL) {
iso_handler_t old = handle->iso_handler[channel];
handle->iso_handler[channel] = NULL;
return old;
} else {
handle->iso_handler[channel] = new;
return NULL;
}
err:
return (iso_handler_t)-1;
}
/**
* raw1394_start_iso_rcv - enable isochronous receiving
* @channel: channel number to start receiving on
*
* Enables the reception of isochronous packets in @channel on @handle.
* Isochronous packets are then passed to the callback specified with
* raw1394_set_iso_handler().
**/
int raw1394_start_iso_rcv(struct raw1394_handle *handle, unsigned int channel)
{
if (!handle->legacy_iso_active || channel > 63) {
errno = EINVAL;
return -1;
}
return raw1394_iso_recv_listen_channel(handle, channel);
}
/**
* raw1394_stop_iso_rcv - stop isochronous receiving
* @channel: channel to stop receiving on
*
* Stops the reception of isochronous packets in @channel on @handle.
**/
int raw1394_stop_iso_rcv(struct raw1394_handle *handle, unsigned int channel)
{
if (!handle->legacy_iso_active || channel > 63) {
errno = EINVAL;
return -1;
}
return raw1394_iso_recv_unlisten_channel(handle, channel);
}
static enum raw1394_iso_disposition legacy_iso_handler(raw1394handle_t handle,
unsigned char *data,
unsigned int len,
unsigned char channel,
unsigned char tag,
unsigned char sy,
unsigned int cycle,
unsigned int dropped)
{
size_t length;
quadlet_t *buf;
if (!handle->iso_handler[channel])
return RAW1394_ISO_OK;
length = len;
buf = (quadlet_t*) data;
/* back up one quadlet to get the ISO header */
/* (note: we assume the card is keeping ISO headers!) */
buf -= 1;
length += 4;
/* pad length to quadlet boundary */
if (length % 4)
length += 4 - (length%4);
/* make the ISO header big-endian, regardless of host byte order */
#ifndef WORDS_BIGENDIAN
buf[0] = bswap_32(buf[0]);
#endif
if (handle->iso_handler[channel](handle, channel, length, buf))
return RAW1394_ISO_ERROR;
return RAW1394_ISO_OK;
}
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