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
  22 struct 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[]).  */
  40 struct 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
  66 enum 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 */
  69 enum 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
  76 struct 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
 156 struct 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*));
 163 struct 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*));
 170 int hpsb_iso_recv_listen_channel(struct hpsb_iso *iso, unsigned char channel);
 171 int hpsb_iso_recv_unlisten_channel(struct hpsb_iso *iso, unsigned char channel);
 172 int hpsb_iso_recv_set_channel_mask(struct hpsb_iso *iso, u64 mask);
 173 int hpsb_iso_xmit_start(struct hpsb_iso *iso, int start_on_cycle,
 174                         int prebuffer);
 175 int hpsb_iso_recv_start(struct hpsb_iso *iso, int start_on_cycle,
 176                         int tag_mask, int sync);
 177 void hpsb_iso_stop(struct hpsb_iso *iso);
 178 void hpsb_iso_shutdown(struct hpsb_iso *iso);
 179 int hpsb_iso_xmit_queue_packet(struct hpsb_iso *iso, u32 offset, u16 len,
 180                                u8 tag, u8 sy);
 181 int hpsb_iso_xmit_sync(struct hpsb_iso *iso);
 182 int hpsb_iso_recv_release_packets(struct hpsb_iso *recv,
 183                                   unsigned int n_packets);
 184 int hpsb_iso_recv_flush(struct hpsb_iso *iso);
 185 int hpsb_iso_n_ready(struct hpsb_iso *iso);
 186
 187 /* the following are callbacks available to low-level drivers */
 188
 189 void hpsb_iso_packet_sent(struct hpsb_iso *iso, int cycle, int error);
 190 void 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);
 193 void hpsb_iso_wake(struct hpsb_iso *iso);
 194
 195 #endif /* IEEE1394_ISO_H */