4 * kernel ISO transmission/reception
6 * Copyright (C) 2002 Maas Digital LLC
8 * This code is licensed under the GPL. See the file COPYING in the root
9 * directory of the kernel sources for details.
12 #ifndef IEEE1394_ISO_H
13 #define IEEE1394_ISO_H
18 /* high-level ISO interface */
20 /* This API sends and receives isochronous packets on a large,
21 virtually-contiguous kernel memory buffer. The buffer may be mapped
22 into a user-space process for zero-copy transmission and reception.
24 There are no explicit boundaries between packets in the buffer. A
25 packet may be transmitted or received at any location. However,
26 low-level drivers may impose certain restrictions on alignment or
27 size of packets. (e.g. in OHCI no packet may cross a page boundary,
28 and packets should be quadlet-aligned)
31 /* Packet descriptor - the API maintains a ring buffer of these packet
32 descriptors in kernel memory (hpsb_iso.infos[]). */
34 struct hpsb_iso_packet_info {
35 /* offset of data payload relative to the first byte of the buffer */
38 /* length of the data payload, in bytes (not including the isochronous header) */
41 /* (recv only) the cycle number (mod 8000) on which the packet was received */
44 /* (recv only) channel on which the packet was received */
47 /* 2-bit 'tag' and 4-bit 'sy' fields of the isochronous header */
52 enum hpsb_iso_type { HPSB_ISO_RECV = 0, HPSB_ISO_XMIT = 1 };
55 enum hpsb_iso_type type;
57 /* pointer to low-level driver and its private data */
58 struct hpsb_host *host;
61 /* a function to be called (from interrupt context) after
62 outgoing packets have been sent, or incoming packets have
64 void (*callback)(struct hpsb_iso*);
66 /* wait for buffer space */
67 wait_queue_head_t waitq;
69 int speed; /* IEEE1394_SPEED_100, 200, or 400 */
70 int channel; /* -1 if multichannel */
72 /* greatest # of packets between interrupts - controls
73 the maximum latency of the buffer */
76 /* the buffer for packet data payloads */
77 struct dma_region data_buf;
79 /* size of data_buf, in bytes (always a multiple of PAGE_SIZE) */
80 unsigned int buf_size;
82 /* # of packets in the ringbuffer */
83 unsigned int buf_packets;
85 /* protects packet cursors */
88 /* the index of the next packet that will be produced
89 or consumed by the user */
92 /* the index of the next packet that will be transmitted
93 or received by the 1394 hardware */
96 /* how many packets, starting at first_packet:
97 (transmit) are ready to be filled with data
98 (receive) contain received data */
101 /* how many times the buffer has overflowed or underflowed */
104 /* private flags to track initialization progress */
105 #define HPSB_ISO_DRIVER_INIT (1<<0)
106 #define HPSB_ISO_DRIVER_STARTED (1<<1)
109 /* # of packets left to prebuffer (xmit only) */
112 /* starting cycle for DMA (xmit only) */
115 /* cycle at which next packet will be transmitted,
119 /* ringbuffer of packet descriptors in regular kernel memory
120 * XXX Keep this last, since we use over-allocated memory from
121 * this entry to fill this field. */
122 struct hpsb_iso_packet_info *infos;
125 /* functions available to high-level drivers (e.g. raw1394) */
127 /* allocate the buffer and DMA context */
129 struct hpsb_iso* hpsb_iso_xmit_init(struct hpsb_host *host,
130 unsigned int data_buf_size,
131 unsigned int buf_packets,
135 void (*callback)(struct hpsb_iso*));
137 /* note: if channel = -1, multi-channel receive is enabled */
138 struct hpsb_iso* hpsb_iso_recv_init(struct hpsb_host *host,
139 unsigned int data_buf_size,
140 unsigned int buf_packets,
143 void (*callback)(struct hpsb_iso*));
145 /* multi-channel only */
146 int hpsb_iso_recv_listen_channel(struct hpsb_iso *iso, unsigned char channel);
147 int hpsb_iso_recv_unlisten_channel(struct hpsb_iso *iso, unsigned char channel);
148 int hpsb_iso_recv_set_channel_mask(struct hpsb_iso *iso, u64 mask);
151 int hpsb_iso_xmit_start(struct hpsb_iso *iso, int start_on_cycle, int prebuffer);
152 int hpsb_iso_recv_start(struct hpsb_iso *iso, int start_on_cycle, int tag_mask, int sync);
153 void hpsb_iso_stop(struct hpsb_iso *iso);
155 /* deallocate buffer and DMA context */
156 void hpsb_iso_shutdown(struct hpsb_iso *iso);
158 /* queue a packet for transmission. 'offset' is relative to the beginning of the
159 DMA buffer, where the packet's data payload should already have been placed */
160 int hpsb_iso_xmit_queue_packet(struct hpsb_iso *iso, u32 offset, u16 len, u8 tag, u8 sy);
162 /* wait until all queued packets have been transmitted to the bus */
163 int hpsb_iso_xmit_sync(struct hpsb_iso *iso);
165 /* N packets have been read out of the buffer, re-use the buffer space */
166 int hpsb_iso_recv_release_packets(struct hpsb_iso *recv, unsigned int n_packets);
168 /* check for arrival of new packets immediately (even if irq_interval
169 has not yet been reached) */
170 int hpsb_iso_recv_flush(struct hpsb_iso *iso);
172 /* returns # of packets ready to send or receive */
173 int hpsb_iso_n_ready(struct hpsb_iso *iso);
175 /* the following are callbacks available to low-level drivers */
177 /* call after a packet has been transmitted to the bus (interrupt context is OK)
178 'cycle' is the _exact_ cycle the packet was sent on
179 'error' should be non-zero if some sort of error occurred when sending the packet
181 void hpsb_iso_packet_sent(struct hpsb_iso *iso, int cycle, int error);
183 /* call after a packet has been received (interrupt context OK) */
184 void hpsb_iso_packet_received(struct hpsb_iso *iso, u32 offset, u16 len,
185 u16 cycle, u8 channel, u8 tag, u8 sy);
187 /* call to wake waiting processes after buffer space has opened up. */
188 void hpsb_iso_wake(struct hpsb_iso *iso);
190 #endif /* IEEE1394_ISO_H */