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 "hosts.h"
16 #include "dma.h"
17
18 /* high-level ISO interface */
19
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.
23
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)
29 */
30
31 /* Packet descriptor - the API maintains a ring buffer of these packet
32 descriptors in kernel memory (hpsb_iso.infos[]). */
33
34 struct hpsb_iso_packet_info {
35 /* offset of data payload relative to the first byte of the buffer */
36 __u32 offset;
37
38 /* length of the data payload, in bytes (not including the isochronous header) */
39 __u16 len;
40
41 /* (recv only) the cycle number (mod 8000) on which the packet was received */
42 __u16 cycle;
43
44 /* (recv only) channel on which the packet was received */
45 __u8 channel;
46
47 /* 2-bit 'tag' and 4-bit 'sy' fields of the isochronous header */
48 __u8 tag;
49 __u8 sy;
50
51 /*
52 * length in bytes of the packet including header/trailer.
53 * MUST be at structure end, since the first part of this structure is also
54 * defined in raw1394.h (i.e. struct raw1394_iso_packet_info), is copied to
55 * userspace and is accessed there through libraw1394.
56 */
57 __u16 total_len;
58 };
59
60 enum hpsb_iso_type { HPSB_ISO_RECV = 0, HPSB_ISO_XMIT = 1 };
61
62 /* The mode of the dma when receiving iso data. Must be supported by chip */
63 enum raw1394_iso_dma_recv_mode {
64 HPSB_ISO_DMA_DEFAULT = -1,
65 HPSB_ISO_DMA_OLD_ABI = 0,
66 HPSB_ISO_DMA_BUFFERFILL = 1,
67 HPSB_ISO_DMA_PACKET_PER_BUFFER = 2
68 };
69
70 struct hpsb_iso {
71 enum hpsb_iso_type type;
72
73 /* pointer to low-level driver and its private data */
74 struct hpsb_host *host;
75 void *hostdata;
76
77 /* a function to be called (from interrupt context) after
78 outgoing packets have been sent, or incoming packets have
79 arrived */
80 void (*callback)(struct hpsb_iso*);
81
82 /* wait for buffer space */
83 wait_queue_head_t waitq;
84
85 int speed; /* IEEE1394_SPEED_100, 200, or 400 */
86 int channel; /* -1 if multichannel */
87 int dma_mode; /* dma receive mode */
88
89
90 /* greatest # of packets between interrupts - controls
91 the maximum latency of the buffer */
92 int irq_interval;
93
94 /* the buffer for packet data payloads */
95 struct dma_region data_buf;
96
97 /* size of data_buf, in bytes (always a multiple of PAGE_SIZE) */
98 unsigned int buf_size;
99
100 /* # of packets in the ringbuffer */
101 unsigned int buf_packets;
102
103 /* protects packet cursors */
104 spinlock_t lock;
105
106 /* the index of the next packet that will be produced
107 or consumed by the user */
108 int first_packet;
109
110 /* the index of the next packet that will be transmitted
111 or received by the 1394 hardware */
112 int pkt_dma;
113
114 /* how many packets, starting at first_packet:
115 (transmit) are ready to be filled with data
116 (receive) contain received data */
117 int n_ready_packets;
118
119 /* how many times the buffer has overflowed or underflowed */
120 atomic_t overflows;
121
122 /* Current number of bytes lost in discarded packets */
123 int bytes_discarded;
124
125 /* private flags to track initialization progress */
126 #define HPSB_ISO_DRIVER_INIT (1<<0)
127 #define HPSB_ISO_DRIVER_STARTED (1<<1)
128 unsigned int flags;
129
130 /* # of packets left to prebuffer (xmit only) */
131 int prebuffer;
132
133 /* starting cycle for DMA (xmit only) */
134 int start_cycle;
135
136 /* cycle at which next packet will be transmitted,
137 -1 if not known */
138 int xmit_cycle;
139
140 /* ringbuffer of packet descriptors in regular kernel memory
141 * XXX Keep this last, since we use over-allocated memory from
142 * this entry to fill this field. */
143 struct hpsb_iso_packet_info *infos;
144 };
145
146 /* functions available to high-level drivers (e.g. raw1394) */
147
148 /* allocate the buffer and DMA context */
149
150 struct hpsb_iso* hpsb_iso_xmit_init(struct hpsb_host *host,
151 unsigned int data_buf_size,
152 unsigned int buf_packets,
153 int channel,
154 int speed,
155 int irq_interval,
156 void (*callback)(struct hpsb_iso*));
157
158 /* note: if channel = -1, multi-channel receive is enabled */
159 struct hpsb_iso* hpsb_iso_recv_init(struct hpsb_host *host,
160 unsigned int data_buf_size,
161 unsigned int buf_packets,
162 int channel,
163 int dma_mode,
164 int irq_interval,
165 void (*callback)(struct hpsb_iso*));
166
167 /* multi-channel only */
168 int hpsb_iso_recv_listen_channel(struct hpsb_iso *iso, unsigned char channel);
169 int hpsb_iso_recv_unlisten_channel(struct hpsb_iso *iso, unsigned char channel);
170 int hpsb_iso_recv_set_channel_mask(struct hpsb_iso *iso, u64 mask);
171
172 /* start/stop DMA */
173 int hpsb_iso_xmit_start(struct hpsb_iso *iso, int start_on_cycle, int prebuffer);
174 int hpsb_iso_recv_start(struct hpsb_iso *iso, int start_on_cycle, int tag_mask, int sync);
175 void hpsb_iso_stop(struct hpsb_iso *iso);
176
177 /* deallocate buffer and DMA context */
178 void hpsb_iso_shutdown(struct hpsb_iso *iso);
179
180 /* queue a packet for transmission. 'offset' is relative to the beginning of the
181 DMA buffer, where the packet's data payload should already have been placed */
182 int hpsb_iso_xmit_queue_packet(struct hpsb_iso *iso, u32 offset, u16 len, u8 tag, u8 sy);
183
184 /* wait until all queued packets have been transmitted to the bus */
185 int hpsb_iso_xmit_sync(struct hpsb_iso *iso);
186
187 /* N packets have been read out of the buffer, re-use the buffer space */
188 int hpsb_iso_recv_release_packets(struct hpsb_iso *recv, unsigned int n_packets);
189
190 /* check for arrival of new packets immediately (even if irq_interval
191 has not yet been reached) */
192 int hpsb_iso_recv_flush(struct hpsb_iso *iso);
193
194 /* returns # of packets ready to send or receive */
195 int hpsb_iso_n_ready(struct hpsb_iso *iso);
196
197 /* the following are callbacks available to low-level drivers */
198
199 /* call after a packet has been transmitted to the bus (interrupt context is OK)
200 'cycle' is the _exact_ cycle the packet was sent on
201 'error' should be non-zero if some sort of error occurred when sending the packet
202 */
203 void hpsb_iso_packet_sent(struct hpsb_iso *iso, int cycle, int error);
204
205 /* call after a packet has been received (interrupt context OK) */
206 void hpsb_iso_packet_received(struct hpsb_iso *iso, u32 offset, u16 len,
207 u16 total_len, u16 cycle, u8 channel, u8 tag, u8 sy);
208
209 /* call to wake waiting processes after buffer space has opened up. */
210 void hpsb_iso_wake(struct hpsb_iso *iso);
211
212 #endif /* IEEE1394_ISO_H */
213
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