213 lines
6.7 KiB
C
213 lines
6.7 KiB
C
/*
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* IEEE 1394 for Linux
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*
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* kernel ISO transmission/reception
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*
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* Copyright (C) 2002 Maas Digital LLC
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*
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* This code is licensed under the GPL. See the file COPYING in the root
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* directory of the kernel sources for details.
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*/
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#ifndef IEEE1394_ISO_H
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#define IEEE1394_ISO_H
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#include "hosts.h"
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#include "dma.h"
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/* high-level ISO interface */
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/* This API sends and receives isochronous packets on a large,
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virtually-contiguous kernel memory buffer. The buffer may be mapped
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into a user-space process for zero-copy transmission and reception.
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There are no explicit boundaries between packets in the buffer. A
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packet may be transmitted or received at any location. However,
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low-level drivers may impose certain restrictions on alignment or
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size of packets. (e.g. in OHCI no packet may cross a page boundary,
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and packets should be quadlet-aligned)
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*/
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/* Packet descriptor - the API maintains a ring buffer of these packet
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descriptors in kernel memory (hpsb_iso.infos[]). */
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struct hpsb_iso_packet_info {
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/* offset of data payload relative to the first byte of the buffer */
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__u32 offset;
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/* length of the data payload, in bytes (not including the isochronous header) */
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__u16 len;
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/* (recv only) the cycle number (mod 8000) on which the packet was received */
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__u16 cycle;
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/* (recv only) channel on which the packet was received */
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__u8 channel;
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/* 2-bit 'tag' and 4-bit 'sy' fields of the isochronous header */
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__u8 tag;
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__u8 sy;
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/*
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* length in bytes of the packet including header/trailer.
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* MUST be at structure end, since the first part of this structure is also
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* defined in raw1394.h (i.e. struct raw1394_iso_packet_info), is copied to
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* userspace and is accessed there through libraw1394.
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*/
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__u16 total_len;
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};
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enum hpsb_iso_type { HPSB_ISO_RECV = 0, HPSB_ISO_XMIT = 1 };
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/* The mode of the dma when receiving iso data. Must be supported by chip */
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enum raw1394_iso_dma_recv_mode {
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HPSB_ISO_DMA_DEFAULT = -1,
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HPSB_ISO_DMA_OLD_ABI = 0,
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HPSB_ISO_DMA_BUFFERFILL = 1,
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HPSB_ISO_DMA_PACKET_PER_BUFFER = 2
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};
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struct hpsb_iso {
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enum hpsb_iso_type type;
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/* pointer to low-level driver and its private data */
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struct hpsb_host *host;
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void *hostdata;
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/* a function to be called (from interrupt context) after
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outgoing packets have been sent, or incoming packets have
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arrived */
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void (*callback)(struct hpsb_iso*);
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/* wait for buffer space */
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wait_queue_head_t waitq;
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int speed; /* IEEE1394_SPEED_100, 200, or 400 */
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int channel; /* -1 if multichannel */
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int dma_mode; /* dma receive mode */
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/* greatest # of packets between interrupts - controls
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the maximum latency of the buffer */
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int irq_interval;
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/* the buffer for packet data payloads */
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struct dma_region data_buf;
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/* size of data_buf, in bytes (always a multiple of PAGE_SIZE) */
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unsigned int buf_size;
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/* # of packets in the ringbuffer */
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unsigned int buf_packets;
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/* protects packet cursors */
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spinlock_t lock;
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/* the index of the next packet that will be produced
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or consumed by the user */
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int first_packet;
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/* the index of the next packet that will be transmitted
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or received by the 1394 hardware */
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int pkt_dma;
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/* how many packets, starting at first_packet:
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(transmit) are ready to be filled with data
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(receive) contain received data */
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int n_ready_packets;
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/* how many times the buffer has overflowed or underflowed */
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atomic_t overflows;
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/* Current number of bytes lost in discarded packets */
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int bytes_discarded;
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/* private flags to track initialization progress */
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#define HPSB_ISO_DRIVER_INIT (1<<0)
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#define HPSB_ISO_DRIVER_STARTED (1<<1)
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unsigned int flags;
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/* # of packets left to prebuffer (xmit only) */
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int prebuffer;
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/* starting cycle for DMA (xmit only) */
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int start_cycle;
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/* cycle at which next packet will be transmitted,
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-1 if not known */
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int xmit_cycle;
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/* ringbuffer of packet descriptors in regular kernel memory
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* XXX Keep this last, since we use over-allocated memory from
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* this entry to fill this field. */
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struct hpsb_iso_packet_info *infos;
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};
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/* functions available to high-level drivers (e.g. raw1394) */
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/* allocate the buffer and DMA context */
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struct hpsb_iso* hpsb_iso_xmit_init(struct hpsb_host *host,
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unsigned int data_buf_size,
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unsigned int buf_packets,
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int channel,
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int speed,
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int irq_interval,
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void (*callback)(struct hpsb_iso*));
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/* note: if channel = -1, multi-channel receive is enabled */
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struct hpsb_iso* hpsb_iso_recv_init(struct hpsb_host *host,
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unsigned int data_buf_size,
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unsigned int buf_packets,
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int channel,
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int dma_mode,
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int irq_interval,
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void (*callback)(struct hpsb_iso*));
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/* multi-channel only */
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int hpsb_iso_recv_listen_channel(struct hpsb_iso *iso, unsigned char channel);
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int hpsb_iso_recv_unlisten_channel(struct hpsb_iso *iso, unsigned char channel);
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int hpsb_iso_recv_set_channel_mask(struct hpsb_iso *iso, u64 mask);
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/* start/stop DMA */
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int hpsb_iso_xmit_start(struct hpsb_iso *iso, int start_on_cycle, int prebuffer);
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int hpsb_iso_recv_start(struct hpsb_iso *iso, int start_on_cycle, int tag_mask, int sync);
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void hpsb_iso_stop(struct hpsb_iso *iso);
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/* deallocate buffer and DMA context */
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void hpsb_iso_shutdown(struct hpsb_iso *iso);
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/* queue a packet for transmission. 'offset' is relative to the beginning of the
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DMA buffer, where the packet's data payload should already have been placed */
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int hpsb_iso_xmit_queue_packet(struct hpsb_iso *iso, u32 offset, u16 len, u8 tag, u8 sy);
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/* wait until all queued packets have been transmitted to the bus */
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int hpsb_iso_xmit_sync(struct hpsb_iso *iso);
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/* N packets have been read out of the buffer, re-use the buffer space */
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int hpsb_iso_recv_release_packets(struct hpsb_iso *recv, unsigned int n_packets);
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/* check for arrival of new packets immediately (even if irq_interval
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has not yet been reached) */
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int hpsb_iso_recv_flush(struct hpsb_iso *iso);
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/* returns # of packets ready to send or receive */
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int hpsb_iso_n_ready(struct hpsb_iso *iso);
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/* the following are callbacks available to low-level drivers */
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/* call after a packet has been transmitted to the bus (interrupt context is OK)
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'cycle' is the _exact_ cycle the packet was sent on
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'error' should be non-zero if some sort of error occurred when sending the packet
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*/
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void hpsb_iso_packet_sent(struct hpsb_iso *iso, int cycle, int error);
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/* call after a packet has been received (interrupt context OK) */
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void hpsb_iso_packet_received(struct hpsb_iso *iso, u32 offset, u16 len,
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u16 total_len, u16 cycle, u8 channel, u8 tag, u8 sy);
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/* call to wake waiting processes after buffer space has opened up. */
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void hpsb_iso_wake(struct hpsb_iso *iso);
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#endif /* IEEE1394_ISO_H */
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