/** 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 mappedinto 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 packetdescriptors 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 };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 */					 /* 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)#define HPSB_ISO_DRIVER_STARTED  (1<<1)	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 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 theDMA 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_intervalhas 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 */