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