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* IEEE 1394 for Linux
* kernel ISO transmission/reception
* Copyright (C) 2002 Maas Digital LLC
* This code is licensed under the GPL. See the file COPYING in the root
* directory of the kernel sources for details.
#ifndef IEEE1394_ISO_H
#define IEEE1394_ISO_H
#include "hosts.h"
#include "dma.h"
/* high-level ISO interface */
/* This API sends and receives isochronous packets on a large,
virtually-contiguous kernel memory buffer. The buffer may be mapped
into a user-space process for zero-copy transmission and reception.
There are no explicit boundaries between packets in the buffer. A
packet may be transmitted or received at any location. However,
low-level drivers may impose certain restrictions on alignment or
size of packets. (e.g. in OHCI no packet may cross a page boundary,
and packets should be quadlet-aligned)
/* Packet descriptor - the API maintains a ring buffer of these packet
descriptors in kernel memory (hpsb_iso.infos[]). */
struct hpsb_iso_packet_info {
/* offset of data payload relative to the first byte of the buffer */
__u32 offset;
/* length of the data payload, in bytes (not including the isochronous header) */
__u16 len;
/* (recv only) the cycle number (mod 8000) on which the packet was received */
__u16 cycle;
/* (recv only) channel on which the packet was received */
__u8 channel;
/* 2-bit 'tag' and 4-bit 'sy' fields of the isochronous header */
__u8 tag;
__u8 sy;
enum hpsb_iso_type { HPSB_ISO_RECV = 0, HPSB_ISO_XMIT = 1 };
/* The mode of the dma when receiving iso data. Must be supported by chip */
enum raw1394_iso_dma_recv_mode {
struct hpsb_iso {
enum hpsb_iso_type type;
/* pointer to low-level driver and its private data */
struct hpsb_host *host;
void *hostdata;
/* a function to be called (from interrupt context) after
outgoing packets have been sent, or incoming packets have
arrived */
void (*callback)(struct hpsb_iso*);
/* wait for buffer space */
wait_queue_head_t waitq;
int speed; /* IEEE1394_SPEED_100, 200, or 400 */
int channel; /* -1 if multichannel */
int dma_mode; /* dma receive mode */
/* greatest # of packets between interrupts - controls
the maximum latency of the buffer */
int irq_interval;
/* the buffer for packet data payloads */
struct dma_region data_buf;
/* size of data_buf, in bytes (always a multiple of PAGE_SIZE) */
unsigned int buf_size;
/* # of packets in the ringbuffer */
unsigned int buf_packets;
/* protects packet cursors */
spinlock_t lock;
/* the index of the next packet that will be produced
or consumed by the user */
int first_packet;
/* the index of the next packet that will be transmitted
or received by the 1394 hardware */
int pkt_dma;
/* how many packets, starting at first_packet:
(transmit) are ready to be filled with data
(receive) contain received data */
int n_ready_packets;
/* how many times the buffer has overflowed or underflowed */
atomic_t overflows;
/* private flags to track initialization progress */
#define HPSB_ISO_DRIVER_INIT (1<<0)
unsigned int flags;
/* # of packets left to prebuffer (xmit only) */
int prebuffer;
/* starting cycle for DMA (xmit only) */
int start_cycle;
/* cycle at which next packet will be transmitted,
-1 if not known */
int xmit_cycle;
/* ringbuffer of packet descriptors in regular kernel memory
* XXX Keep this last, since we use over-allocated memory from
* this entry to fill this field. */
struct hpsb_iso_packet_info *infos;
/* functions available to high-level drivers (e.g. raw1394) */
/* allocate the buffer and DMA context */
struct hpsb_iso* hpsb_iso_xmit_init(struct hpsb_host *host,
unsigned int data_buf_size,
unsigned int buf_packets,
int channel,
int speed,
int irq_interval,
void (*callback)(struct hpsb_iso*));
/* note: if channel = -1, multi-channel receive is enabled */
struct hpsb_iso* hpsb_iso_recv_init(struct hpsb_host *host,
unsigned int data_buf_size,
unsigned int buf_packets,
int channel,
int dma_mode,
int irq_interval,
void (*callback)(struct hpsb_iso*));
/* multi-channel only */
int hpsb_iso_recv_listen_channel(struct hpsb_iso *iso, unsigned char channel);
int hpsb_iso_recv_unlisten_channel(struct hpsb_iso *iso, unsigned char channel);
int hpsb_iso_recv_set_channel_mask(struct hpsb_iso *iso, u64 mask);
/* start/stop DMA */
int hpsb_iso_xmit_start(struct hpsb_iso *iso, int start_on_cycle, int prebuffer);
int hpsb_iso_recv_start(struct hpsb_iso *iso, int start_on_cycle, int tag_mask, int sync);
void hpsb_iso_stop(struct hpsb_iso *iso);
/* deallocate buffer and DMA context */
void hpsb_iso_shutdown(struct hpsb_iso *iso);
/* queue a packet for transmission. 'offset' is relative to the beginning of the
DMA buffer, where the packet's data payload should already have been placed */
int hpsb_iso_xmit_queue_packet(struct hpsb_iso *iso, u32 offset, u16 len, u8 tag, u8 sy);
/* wait until all queued packets have been transmitted to the bus */
int hpsb_iso_xmit_sync(struct hpsb_iso *iso);
/* N packets have been read out of the buffer, re-use the buffer space */
int hpsb_iso_recv_release_packets(struct hpsb_iso *recv, unsigned int n_packets);
/* check for arrival of new packets immediately (even if irq_interval
has not yet been reached) */
int hpsb_iso_recv_flush(struct hpsb_iso *iso);
/* returns # of packets ready to send or receive */
int hpsb_iso_n_ready(struct hpsb_iso *iso);
/* the following are callbacks available to low-level drivers */
/* call after a packet has been transmitted to the bus (interrupt context is OK)
'cycle' is the _exact_ cycle the packet was sent on
'error' should be non-zero if some sort of error occurred when sending the packet
void hpsb_iso_packet_sent(struct hpsb_iso *iso, int cycle, int error);
/* call after a packet has been received (interrupt context OK) */
void hpsb_iso_packet_received(struct hpsb_iso *iso, u32 offset, u16 len,
u16 cycle, u8 channel, u8 tag, u8 sy);
/* call to wake waiting processes after buffer space has opened up. */
void hpsb_iso_wake(struct hpsb_iso *iso);
#endif /* IEEE1394_ISO_H */