LXR linux/drivers/ieee1394/iso.h

   1/*
   2 * IEEE 1394 for Linux
   3 *
   4 * kernel ISO transmission/reception
   5 *
   6 * Copyright (C) 2002 Maas Digital LLC
   7 *
   8 * This code is licensed under the GPL.  See the file COPYING in the root
   9 * directory of the kernel sources for details.
  10 */
  11
  12#ifndef IEEE1394_ISO_H
  13#define IEEE1394_ISO_H
  14
  15#include <linux/spinlock_types.h>
  16#include <linux/wait.h>
  17#include <asm/atomic.h>
  18#include <asm/types.h>
  19
  20#include "dma.h"
  21
  22struct hpsb_host;
  23
  24/* high-level ISO interface */
  25
  26/*
  27 * This API sends and receives isochronous packets on a large,
  28 * virtually-contiguous kernel memory buffer. The buffer may be mapped
  29 * into a user-space process for zero-copy transmission and reception.
  30 *
  31 * There are no explicit boundaries between packets in the buffer. A
  32 * packet may be transmitted or received at any location. However,
  33 * low-level drivers may impose certain restrictions on alignment or
  34 * size of packets. (e.g. in OHCI no packet may cross a page boundary,
  35 * and packets should be quadlet-aligned)
  36 */
  37
  38/* Packet descriptor - the API maintains a ring buffer of these packet
  39 * descriptors in kernel memory (hpsb_iso.infos[]).  */
  40struct hpsb_iso_packet_info {
  41        /* offset of data payload relative to the first byte of the buffer */
  42        __u32 offset;
  43
  44        /* length of the data payload, in bytes (not including the isochronous
  45         * header) */
  46        __u16 len;
  47
  48        /* (recv only) the cycle number (mod 8000) on which the packet was
  49         * received */
  50        __u16 cycle;
  51
  52        /* (recv only) channel on which the packet was received */
  53        __u8 channel;
  54
  55        /* 2-bit 'tag' and 4-bit 'sy' fields of the isochronous header */
  56        __u8 tag;
  57        __u8 sy;
  58
  59        /* length in bytes of the packet including header/trailer.
  60         * MUST be at structure end, since the first part of this structure is
  61         * also defined in raw1394.h (i.e. struct raw1394_iso_packet_info), is
  62         * copied to userspace and is accessed there through libraw1394. */
  63        __u16 total_len;
  64};
  65
  66enum hpsb_iso_type { HPSB_ISO_RECV = 0, HPSB_ISO_XMIT = 1 };
  67
  68/* The mode of the dma when receiving iso data. Must be supported by chip */
  69enum raw1394_iso_dma_recv_mode {
  70        HPSB_ISO_DMA_DEFAULT = -1,
  71        HPSB_ISO_DMA_OLD_ABI = 0,
  72        HPSB_ISO_DMA_BUFFERFILL = 1,
  73        HPSB_ISO_DMA_PACKET_PER_BUFFER = 2
  74};
  75
  76struct hpsb_iso {
  77        enum hpsb_iso_type type;
  78
  79        /* pointer to low-level driver and its private data */
  80        struct hpsb_host *host;
  81        void *hostdata;
  82
  83        /* a function to be called (from interrupt context) after
  84         * outgoing packets have been sent, or incoming packets have
  85         * arrived */
  86        void (*callback)(struct hpsb_iso*);
  87
  88        /* wait for buffer space */
  89        wait_queue_head_t waitq;
  90
  91        int speed; /* IEEE1394_SPEED_100, 200, or 400 */
  92        int channel; /* -1 if multichannel */
  93        int dma_mode; /* dma receive mode */
  94
  95
  96        /* greatest # of packets between interrupts - controls
  97         * the maximum latency of the buffer */
  98        int irq_interval;
  99
 100        /* the buffer for packet data payloads */
 101        struct dma_region data_buf;
 102
 103        /* size of data_buf, in bytes (always a multiple of PAGE_SIZE) */
 104        unsigned int buf_size;
 105
 106        /* # of packets in the ringbuffer */
 107        unsigned int buf_packets;
 108
 109        /* protects packet cursors */
 110        spinlock_t lock;
 111
 112        /* the index of the next packet that will be produced
 113           or consumed by the user */
 114        int first_packet;
 115
 116        /* the index of the next packet that will be transmitted
 117           or received by the 1394 hardware */
 118        int pkt_dma;
 119
 120        /* how many packets, starting at first_packet:
 121         * (transmit) are ready to be filled with data
 122         * (receive)  contain received data */
 123        int n_ready_packets;
 124
 125        /* how many times the buffer has overflowed or underflowed */
 126        atomic_t overflows;
 127        /* how many cycles were skipped for a given context */
 128        atomic_t skips;
 129
 130        /* Current number of bytes lost in discarded packets */
 131        int bytes_discarded;
 132
 133        /* private flags to track initialization progress */
 134#define HPSB_ISO_DRIVER_INIT     (1<<0)
 135#define HPSB_ISO_DRIVER_STARTED  (1<<1)
 136        unsigned int flags;
 137
 138        /* # of packets left to prebuffer (xmit only) */
 139        int prebuffer;
 140
 141        /* starting cycle for DMA (xmit only) */
 142        int start_cycle;
 143
 144        /* cycle at which next packet will be transmitted,
 145         * -1 if not known */
 146        int xmit_cycle;
 147
 148        /* ringbuffer of packet descriptors in regular kernel memory
 149         * XXX Keep this last, since we use over-allocated memory from
 150         * this entry to fill this field. */
 151        struct hpsb_iso_packet_info *infos;
 152};
 153
 154/* functions available to high-level drivers (e.g. raw1394) */
 155
 156struct hpsb_iso* hpsb_iso_xmit_init(struct hpsb_host *host,
 157                                    unsigned int data_buf_size,
 158                                    unsigned int buf_packets,
 159                                    int channel,
 160                                    int speed,
 161                                    int irq_interval,
 162                                    void (*callback)(struct hpsb_iso*));
 163struct hpsb_iso* hpsb_iso_recv_init(struct hpsb_host *host,
 164                                    unsigned int data_buf_size,
 165                                    unsigned int buf_packets,
 166                                    int channel,
 167                                    int dma_mode,
 168                                    int irq_interval,
 169                                    void (*callback)(struct hpsb_iso*));
 170int hpsb_iso_recv_listen_channel(struct hpsb_iso *iso, unsigned char channel);
 171int hpsb_iso_recv_unlisten_channel(struct hpsb_iso *iso, unsigned char channel);
 172int hpsb_iso_recv_set_channel_mask(struct hpsb_iso *iso, u64 mask);
 173int hpsb_iso_xmit_start(struct hpsb_iso *iso, int start_on_cycle,
 174                        int prebuffer);
 175int hpsb_iso_recv_start(struct hpsb_iso *iso, int start_on_cycle,
 176                        int tag_mask, int sync);
 177void hpsb_iso_stop(struct hpsb_iso *iso);
 178void hpsb_iso_shutdown(struct hpsb_iso *iso);
 179int hpsb_iso_xmit_queue_packet(struct hpsb_iso *iso, u32 offset, u16 len,
 180                               u8 tag, u8 sy);
 181int hpsb_iso_xmit_sync(struct hpsb_iso *iso);
 182int hpsb_iso_recv_release_packets(struct hpsb_iso *recv,
 183                                  unsigned int n_packets);
 184int hpsb_iso_recv_flush(struct hpsb_iso *iso);
 185int hpsb_iso_n_ready(struct hpsb_iso *iso);
 186
 187/* the following are callbacks available to low-level drivers */
 188
 189void hpsb_iso_packet_sent(struct hpsb_iso *iso, int cycle, int error);
 190void hpsb_iso_packet_received(struct hpsb_iso *iso, u32 offset, u16 len,
 191                              u16 total_len, u16 cycle, u8 channel, u8 tag,
 192                              u8 sy);
 193void hpsb_iso_wake(struct hpsb_iso *iso);
 194
 195#endif /* IEEE1394_ISO_H */
 196