diff options
Diffstat (limited to 'drivers/ieee1394/iso.h')
| -rw-r--r-- | drivers/ieee1394/iso.h | 80 |
1 files changed, 43 insertions, 37 deletions
diff --git a/drivers/ieee1394/iso.h b/drivers/ieee1394/iso.h index 3efc60b..ed639c4 100644 --- a/drivers/ieee1394/iso.h +++ b/drivers/ieee1394/iso.h @@ -17,28 +17,30 @@ /* 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) -*/ +/* + * 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[]). */ - + * 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) */ + /* 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 */ + /* (recv only) the cycle number (mod 8000) on which the packet was + * received */ __u16 cycle; /* (recv only) channel on which the packet was received */ @@ -48,12 +50,10 @@ struct hpsb_iso_packet_info { __u8 tag; __u8 sy; - /* - * length in bytes of the packet including header/trailer. - * MUST be at structure end, since the first part of this structure is also - * defined in raw1394.h (i.e. struct raw1394_iso_packet_info), is copied to - * userspace and is accessed there through libraw1394. - */ + /* length in bytes of the packet including header/trailer. + * MUST be at structure end, since the first part of this structure is + * also defined in raw1394.h (i.e. struct raw1394_iso_packet_info), is + * copied to userspace and is accessed there through libraw1394. */ __u16 total_len; }; @@ -75,8 +75,8 @@ struct hpsb_iso { void *hostdata; /* a function to be called (from interrupt context) after - outgoing packets have been sent, or incoming packets have - arrived */ + * outgoing packets have been sent, or incoming packets have + * arrived */ void (*callback)(struct hpsb_iso*); /* wait for buffer space */ @@ -88,7 +88,7 @@ struct hpsb_iso { /* greatest # of packets between interrupts - controls - the maximum latency of the buffer */ + * the maximum latency of the buffer */ int irq_interval; /* the buffer for packet data payloads */ @@ -112,8 +112,8 @@ struct hpsb_iso { int pkt_dma; /* how many packets, starting at first_packet: - (transmit) are ready to be filled with data - (receive) contain received data */ + * (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 */ @@ -134,7 +134,7 @@ struct hpsb_iso { int start_cycle; /* cycle at which next packet will be transmitted, - -1 if not known */ + * -1 if not known */ int xmit_cycle; /* ringbuffer of packet descriptors in regular kernel memory @@ -170,25 +170,30 @@ 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); +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); +/* 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); +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) */ + * has not yet been reached) */ int hpsb_iso_recv_flush(struct hpsb_iso *iso); /* returns # of packets ready to send or receive */ @@ -197,14 +202,15 @@ 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 -*/ + * '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 total_len, u16 cycle, u8 channel, u8 tag, u8 sy); + u16 total_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); |
