diff options
Diffstat (limited to 'drivers/ieee1394/iso.h')
| -rw-r--r-- | drivers/ieee1394/iso.h | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/drivers/ieee1394/iso.h b/drivers/ieee1394/iso.h new file mode 100644 index 000000000000..fb654d9639a7 --- /dev/null +++ b/drivers/ieee1394/iso.h @@ -0,0 +1,201 @@ +/* + * 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 }; + +/* The mode of the dma when receiving iso data. Must be supported by chip */ +enum raw1394_iso_dma_recv_mode { + HPSB_ISO_DMA_DEFAULT = -1, + HPSB_ISO_DMA_OLD_ABI = 0, + HPSB_ISO_DMA_BUFFERFILL = 1, + HPSB_ISO_DMA_PACKET_PER_BUFFER = 2 +}; + +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 */ + int dma_mode; /* dma receive mode */ + + + /* 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 dma_mode, + 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 */ |