/* * 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 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[]). */ 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 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); /* check for arrival of new packets immediately (even if irq_interval has 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 */