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1da177e4 LT |
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; | |
1934b8b6 BC |
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; | |
1da177e4 LT |
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 | ||
1934b8b6 BC |
122 | /* Current number of bytes lost in discarded packets */ |
123 | int bytes_discarded; | |
124 | ||
1da177e4 LT |
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, | |
1934b8b6 | 207 | u16 total_len, u16 cycle, u8 channel, u8 tag, u8 sy); |
1da177e4 LT |
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 */ |