summaryrefslogtreecommitdiff
path: root/drivers/media/usb/au0828/au0828-vbi.c
blob: 63f593070ee8b14be8f98e70dc1ab8e8c28c644e (plain)
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
/*
   au0828-vbi.c - VBI driver for au0828

   Copyright (C) 2010 Devin Heitmueller <dheitmueller@kernellabs.com>

   This work was sponsored by GetWellNetwork Inc.

   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.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301, USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>

#include "au0828.h"

static unsigned int vbibufs = 5;
module_param(vbibufs, int, 0644);
MODULE_PARM_DESC(vbibufs, "number of vbi buffers, range 2-32");

/* ------------------------------------------------------------------ */

static void
free_buffer(struct videobuf_queue *vq, struct au0828_buffer *buf)
{
	struct au0828_fh     *fh  = vq->priv_data;
	struct au0828_dev    *dev = fh->dev;
	unsigned long flags = 0;
	if (in_interrupt())
		BUG();

	/* We used to wait for the buffer to finish here, but this didn't work
	   because, as we were keeping the state as VIDEOBUF_QUEUED,
	   videobuf_queue_cancel marked it as finished for us.
	   (Also, it could wedge forever if the hardware was misconfigured.)

	   This should be safe; by the time we get here, the buffer isn't
	   queued anymore. If we ever start marking the buffers as
	   VIDEOBUF_ACTIVE, it won't be, though.
	*/
	spin_lock_irqsave(&dev->slock, flags);
	if (dev->isoc_ctl.vbi_buf == buf)
		dev->isoc_ctl.vbi_buf = NULL;
	spin_unlock_irqrestore(&dev->slock, flags);

	videobuf_vmalloc_free(&buf->vb);
	buf->vb.state = VIDEOBUF_NEEDS_INIT;
}

static int
vbi_setup(struct videobuf_queue *q, unsigned int *count, unsigned int *size)
{
	struct au0828_fh     *fh  = q->priv_data;
	struct au0828_dev    *dev = fh->dev;

	*size = dev->vbi_width * dev->vbi_height * 2;

	if (0 == *count)
		*count = vbibufs;
	if (*count < 2)
		*count = 2;
	if (*count > 32)
		*count = 32;
	return 0;
}

static int
vbi_prepare(struct videobuf_queue *q, struct videobuf_buffer *vb,
	    enum v4l2_field field)
{
	struct au0828_fh     *fh  = q->priv_data;
	struct au0828_dev    *dev = fh->dev;
	struct au0828_buffer *buf = container_of(vb, struct au0828_buffer, vb);
	int                  rc = 0;

	buf->vb.size = dev->vbi_width * dev->vbi_height * 2;

	if (0 != buf->vb.baddr  &&  buf->vb.bsize < buf->vb.size)
		return -EINVAL;

	buf->vb.width  = dev->vbi_width;
	buf->vb.height = dev->vbi_height;
	buf->vb.field  = field;

	if (VIDEOBUF_NEEDS_INIT == buf->vb.state) {
		rc = videobuf_iolock(q, &buf->vb, NULL);
		if (rc < 0)
			goto fail;
	}

	buf->vb.state = VIDEOBUF_PREPARED;
	return 0;

fail:
	free_buffer(q, buf);
	return rc;
}

static void
vbi_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb)
{
	struct au0828_buffer    *buf     = container_of(vb,
							struct au0828_buffer,
							vb);
	struct au0828_fh        *fh      = vq->priv_data;
	struct au0828_dev       *dev     = fh->dev;
	struct au0828_dmaqueue  *vbiq    = &dev->vbiq;

	buf->vb.state = VIDEOBUF_QUEUED;
	list_add_tail(&buf->vb.queue, &vbiq->active);
}

static void vbi_release(struct videobuf_queue *q, struct videobuf_buffer *vb)
{
	struct au0828_buffer *buf = container_of(vb, struct au0828_buffer, vb);
	free_buffer(q, buf);
}

struct videobuf_queue_ops au0828_vbi_qops = {
	.buf_setup    = vbi_setup,
	.buf_prepare  = vbi_prepare,
	.buf_queue    = vbi_queue,
	.buf_release  = vbi_release,
};