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 <linux/spinlock_types.h>
16#include <asm/atomic.h>
17#include <asm/types.h>
18
19#include "dma.h"
20
21struct hpsb_host;
22
23/* high-level ISO interface */
24
25/*
26 * This API sends and receives isochronous packets on a large,
27 * virtually-contiguous kernel memory buffer. The buffer may be mapped
28 * into a user-space process for zero-copy transmission and reception.
29 *
30 * There are no explicit boundaries between packets in the buffer. A
31 * packet may be transmitted or received at any location. However,
32 * low-level drivers may impose certain restrictions on alignment or
33 * size of packets. (e.g. in OHCI no packet may cross a page boundary,
34 * and packets should be quadlet-aligned)
35 */
36
37/* Packet descriptor - the API maintains a ring buffer of these packet
38 * descriptors in kernel memory (hpsb_iso.infos[]).  */
39struct hpsb_iso_packet_info {
40	/* offset of data payload relative to the first byte of the buffer */
41	__u32 offset;
42
43	/* length of the data payload, in bytes (not including the isochronous
44	 * header) */
45	__u16 len;
46
47	/* (recv only) the cycle number (mod 8000) on which the packet was
48	 * received */
49	__u16 cycle;
50
51	/* (recv only) channel on which the packet was received */
52	__u8 channel;
53
54	/* 2-bit 'tag' and 4-bit 'sy' fields of the isochronous header */
55	__u8 tag;
56	__u8 sy;
57
58	/* length in bytes of the packet including header/trailer.
59	 * MUST be at structure end, since the first part of this structure is
60	 * also defined in raw1394.h (i.e. struct raw1394_iso_packet_info), is
61	 * copied to userspace and is accessed there through libraw1394. */
62	__u16 total_len;
63};
64
65enum hpsb_iso_type { HPSB_ISO_RECV = 0, HPSB_ISO_XMIT = 1 };
66
67/* The mode of the dma when receiving iso data. Must be supported by chip */
68enum raw1394_iso_dma_recv_mode {
69	HPSB_ISO_DMA_DEFAULT = -1,
70	HPSB_ISO_DMA_OLD_ABI = 0,
71	HPSB_ISO_DMA_BUFFERFILL = 1,
72	HPSB_ISO_DMA_PACKET_PER_BUFFER = 2
73};
74
75struct hpsb_iso {
76	enum hpsb_iso_type type;
77
78	/* pointer to low-level driver and its private data */
79	struct hpsb_host *host;
80	void *hostdata;
81
82	/* a function to be called (from interrupt context) after
83	 * outgoing packets have been sent, or incoming packets have
84	 * arrived */
85	void (*callback)(struct hpsb_iso*);
86
87	/* wait for buffer space */
88	wait_queue_head_t waitq;
89
90	int speed; /* IEEE1394_SPEED_100, 200, or 400 */
91	int channel; /* -1 if multichannel */
92	int dma_mode; /* dma receive mode */
93
94
95	/* greatest # of packets between interrupts - controls
96	 * the maximum latency of the buffer */
97	int irq_interval;
98
99	/* the buffer for packet data payloads */
100	struct dma_region data_buf;
101
102	/* size of data_buf, in bytes (always a multiple of PAGE_SIZE) */
103	unsigned int buf_size;
104
105	/* # of packets in the ringbuffer */
106	unsigned int buf_packets;
107
108	/* protects packet cursors */
109	spinlock_t lock;
110
111	/* the index of the next packet that will be produced
112	   or consumed by the user */
113	int first_packet;
114
115	/* the index of the next packet that will be transmitted
116	   or received by the 1394 hardware */
117	int pkt_dma;
118
119	/* how many packets, starting at first_packet:
120	 * (transmit) are ready to be filled with data
121	 * (receive)  contain received data */
122	int n_ready_packets;
123
124	/* how many times the buffer has overflowed or underflowed */
125	atomic_t overflows;
126
127	/* Current number of bytes lost in discarded packets */
128	int bytes_discarded;
129
130	/* private flags to track initialization progress */
131#define HPSB_ISO_DRIVER_INIT     (1<<0)
132#define HPSB_ISO_DRIVER_STARTED  (1<<1)
133	unsigned int flags;
134
135	/* # of packets left to prebuffer (xmit only) */
136	int prebuffer;
137
138	/* starting cycle for DMA (xmit only) */
139	int start_cycle;
140
141	/* cycle at which next packet will be transmitted,
142	 * -1 if not known */
143	int xmit_cycle;
144
145	struct hpsb_iso_packet_info *infos;
146};
147
148/* functions available to high-level drivers (e.g. raw1394) */
149
150struct 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*));
157struct hpsb_iso* hpsb_iso_recv_init(struct hpsb_host *host,
158				    unsigned int data_buf_size,
159				    unsigned int buf_packets,
160				    int channel,
161				    int dma_mode,
162				    int irq_interval,
163				    void (*callback)(struct hpsb_iso*));
164int hpsb_iso_recv_listen_channel(struct hpsb_iso *iso, unsigned char channel);
165int hpsb_iso_recv_unlisten_channel(struct hpsb_iso *iso, unsigned char channel);
166int hpsb_iso_recv_set_channel_mask(struct hpsb_iso *iso, u64 mask);
167int hpsb_iso_xmit_start(struct hpsb_iso *iso, int start_on_cycle,
168			int prebuffer);
169int hpsb_iso_recv_start(struct hpsb_iso *iso, int start_on_cycle,
170			int tag_mask, int sync);
171void hpsb_iso_stop(struct hpsb_iso *iso);
172void hpsb_iso_shutdown(struct hpsb_iso *iso);
173int hpsb_iso_xmit_queue_packet(struct hpsb_iso *iso, u32 offset, u16 len,
174			       u8 tag, u8 sy);
175int hpsb_iso_xmit_sync(struct hpsb_iso *iso);
176int hpsb_iso_recv_release_packets(struct hpsb_iso *recv,
177				  unsigned int n_packets);
178int hpsb_iso_recv_flush(struct hpsb_iso *iso);
179int hpsb_iso_n_ready(struct hpsb_iso *iso);
180
181/* the following are callbacks available to low-level drivers */
182
183void hpsb_iso_packet_sent(struct hpsb_iso *iso, int cycle, int error);
184void hpsb_iso_packet_received(struct hpsb_iso *iso, u32 offset, u16 len,
185			      u16 total_len, u16 cycle, u8 channel, u8 tag,
186			      u8 sy);
187void hpsb_iso_wake(struct hpsb_iso *iso);
188
189#endif /* IEEE1394_ISO_H */
190