aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/media/dvb/firewire/cmp.c
blob: 821e033d81958005736ef9542e965e7864874d2b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
/*
 * FireDTV driver (formerly known as FireSAT)
 *
 * Copyright (C) 2004 Andreas Monitzer <andy@monitzer.com>
 * Copyright (C) 2008 Henrik Kurelid <henrik@kurelid.se>
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License as
 *	published by the Free Software Foundation; either version 2 of
 *	the License, or (at your option) any later version.
 */

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/mutex.h>
#include <linux/types.h>

#include <asm/byteorder.h>

#include <ieee1394.h>
#include <nodemgr.h>

#include "avc.h"
#include "cmp.h"
#include "firedtv.h"

#define CMP_OUTPUT_PLUG_CONTROL_REG_0	0xfffff0000904ULL

static int cmp_read(struct firedtv *fdtv, void *buf, u64 addr, size_t len)
{
	int ret;

	if (mutex_lock_interruptible(&fdtv->avc_mutex))
		return -EINTR;

	ret = hpsb_node_read(fdtv->ud->ne, addr, buf, len);
	if (ret < 0)
		dev_err(&fdtv->ud->device, "CMP: read I/O error\n");

	mutex_unlock(&fdtv->avc_mutex);
	return ret;
}

static int cmp_lock(struct firedtv *fdtv, void *data, u64 addr, __be32 arg,
		    int ext_tcode)
{
	int ret;

	if (mutex_lock_interruptible(&fdtv->avc_mutex))
		return -EINTR;

	ret = hpsb_node_lock(fdtv->ud->ne, addr, ext_tcode, data,
			     (__force quadlet_t)arg);
	if (ret < 0)
		dev_err(&fdtv->ud->device, "CMP: lock I/O error\n");

	mutex_unlock(&fdtv->avc_mutex);
	return ret;
}

static inline u32 get_opcr(__be32 opcr, u32 mask, u32 shift)
{
	return (be32_to_cpu(opcr) >> shift) & mask;
}

static inline void set_opcr(__be32 *opcr, u32 value, u32 mask, u32 shift)
{
	*opcr &= ~cpu_to_be32(mask << shift);
	*opcr |= cpu_to_be32((value & mask) << shift);
}

#define get_opcr_online(v)		get_opcr((v), 0x1, 31)
#define get_opcr_p2p_connections(v)	get_opcr((v), 0x3f, 24)
#define get_opcr_channel(v)		get_opcr((v), 0x3f, 16)

#define set_opcr_p2p_connections(p, v)	set_opcr((p), (v), 0x3f, 24)
#define set_opcr_channel(p, v)		set_opcr((p), (v), 0x3f, 16)
#define set_opcr_data_rate(p, v)	set_opcr((p), (v), 0x3, 14)
#define set_opcr_overhead_id(p, v)	set_opcr((p), (v), 0xf, 10)

int cmp_establish_pp_connection(struct firedtv *fdtv, int plug, int channel)
{
	__be32 old_opcr, opcr;
	u64 opcr_address = CMP_OUTPUT_PLUG_CONTROL_REG_0 + (plug << 2);
	int attempts = 0;
	int ret;

	ret = cmp_read(fdtv, &opcr, opcr_address, 4);
	if (ret < 0)
		return ret;

repeat:
	if (!get_opcr_online(opcr)) {
		dev_err(&fdtv->ud->device, "CMP: output offline\n");
		return -EBUSY;
	}

	old_opcr = opcr;

	if (get_opcr_p2p_connections(opcr)) {
		if (get_opcr_channel(opcr) != channel) {
			dev_err(&fdtv->ud->device,
				"CMP: cannot change channel\n");
			return -EBUSY;
		}
		dev_info(&fdtv->ud->device,
			 "CMP: overlaying existing connection\n");

		/* We don't allocate isochronous resources. */
	} else {
		set_opcr_channel(&opcr, channel);
		set_opcr_data_rate(&opcr, IEEE1394_SPEED_400);

		/* FIXME: this is for the worst case - optimize */
		set_opcr_overhead_id(&opcr, 0);

		/* FIXME: allocate isochronous channel and bandwidth at IRM */
	}

	set_opcr_p2p_connections(&opcr, get_opcr_p2p_connections(opcr) + 1);

	ret = cmp_lock(fdtv, &opcr, opcr_address, old_opcr, 2);
	if (ret < 0)
		return ret;

	if (old_opcr != opcr) {
		/*
		 * FIXME: if old_opcr.P2P_Connections > 0,
		 * deallocate isochronous channel and bandwidth at IRM
		 */

		if (++attempts < 6) /* arbitrary limit */
			goto repeat;
		return -EBUSY;
	}

	return 0;
}

void cmp_break_pp_connection(struct firedtv *fdtv, int plug, int channel)
{
	__be32 old_opcr, opcr;
	u64 opcr_address = CMP_OUTPUT_PLUG_CONTROL_REG_0 + (plug << 2);
	int attempts = 0;

	if (cmp_read(fdtv, &opcr, opcr_address, 4) < 0)
		return;

repeat:
	if (!get_opcr_online(opcr) || !get_opcr_p2p_connections(opcr) ||
	    get_opcr_channel(opcr) != channel) {
		dev_err(&fdtv->ud->device, "CMP: no connection to break\n");
		return;
	}

	old_opcr = opcr;
	set_opcr_p2p_connections(&opcr, get_opcr_p2p_connections(opcr) - 1);

	if (cmp_lock(fdtv, &opcr, opcr_address, old_opcr, 2) < 0)
		return;

	if (old_opcr != opcr) {
		/*
		 * FIXME: if old_opcr.P2P_Connections == 1, i.e. we were last
		 * owner, deallocate isochronous channel and bandwidth at IRM
		 */

		if (++attempts < 6) /* arbitrary limit */
			goto repeat;
	}
}