1/*
2   au0828-vbi.c - VBI driver for au0828
3
4   Copyright (C) 2010 Devin Heitmueller <dheitmueller@kernellabs.com>
5
6   This work was sponsored by GetWellNetwork Inc.
7
8   This program is free software; you can redistribute it and/or modify
9   it under the terms of the GNU General Public License as published by
10   the Free Software Foundation; either version 2 of the License, or
11   (at your option) any later version.
12
13   This program is distributed in the hope that it will be useful,
14   but WITHOUT ANY WARRANTY; without even the implied warranty of
15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16   GNU General Public License for more details.
17
18   You should have received a copy of the GNU General Public License
19   along with this program; if not, write to the Free Software
20   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21   02110-1301, USA.
22 */
23
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/init.h>
27#include <linux/slab.h>
28
29#include "au0828.h"
30
31static unsigned int vbibufs = 5;
32module_param(vbibufs, int, 0644);
33MODULE_PARM_DESC(vbibufs, "number of vbi buffers, range 2-32");
34
35/* ------------------------------------------------------------------ */
36
37static void
38free_buffer(struct videobuf_queue *vq, struct au0828_buffer *buf)
39{
40	struct au0828_fh     *fh  = vq->priv_data;
41	struct au0828_dev    *dev = fh->dev;
42	unsigned long flags = 0;
43	if (in_interrupt())
44		BUG();
45
46	/* We used to wait for the buffer to finish here, but this didn't work
47	   because, as we were keeping the state as VIDEOBUF_QUEUED,
48	   videobuf_queue_cancel marked it as finished for us.
49	   (Also, it could wedge forever if the hardware was misconfigured.)
50
51	   This should be safe; by the time we get here, the buffer isn't
52	   queued anymore. If we ever start marking the buffers as
53	   VIDEOBUF_ACTIVE, it won't be, though.
54	*/
55	spin_lock_irqsave(&dev->slock, flags);
56	if (dev->isoc_ctl.vbi_buf == buf)
57		dev->isoc_ctl.vbi_buf = NULL;
58	spin_unlock_irqrestore(&dev->slock, flags);
59
60	videobuf_vmalloc_free(&buf->vb);
61	buf->vb.state = VIDEOBUF_NEEDS_INIT;
62}
63
64static int
65vbi_setup(struct videobuf_queue *q, unsigned int *count, unsigned int *size)
66{
67	struct au0828_fh     *fh  = q->priv_data;
68	struct au0828_dev    *dev = fh->dev;
69
70	*size = dev->vbi_width * dev->vbi_height * 2;
71
72	if (0 == *count)
73		*count = vbibufs;
74	if (*count < 2)
75		*count = 2;
76	if (*count > 32)
77		*count = 32;
78	return 0;
79}
80
81static int
82vbi_prepare(struct videobuf_queue *q, struct videobuf_buffer *vb,
83	    enum v4l2_field field)
84{
85	struct au0828_fh     *fh  = q->priv_data;
86	struct au0828_dev    *dev = fh->dev;
87	struct au0828_buffer *buf = container_of(vb, struct au0828_buffer, vb);
88	int                  rc = 0;
89
90	buf->vb.size = dev->vbi_width * dev->vbi_height * 2;
91
92	if (0 != buf->vb.baddr  &&  buf->vb.bsize < buf->vb.size)
93		return -EINVAL;
94
95	buf->vb.width  = dev->vbi_width;
96	buf->vb.height = dev->vbi_height;
97	buf->vb.field  = field;
98
99	if (VIDEOBUF_NEEDS_INIT == buf->vb.state) {
100		rc = videobuf_iolock(q, &buf->vb, NULL);
101		if (rc < 0)
102			goto fail;
103	}
104
105	buf->vb.state = VIDEOBUF_PREPARED;
106	return 0;
107
108fail:
109	free_buffer(q, buf);
110	return rc;
111}
112
113static void
114vbi_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb)
115{
116	struct au0828_buffer    *buf     = container_of(vb,
117							struct au0828_buffer,
118							vb);
119	struct au0828_fh        *fh      = vq->priv_data;
120	struct au0828_dev       *dev     = fh->dev;
121	struct au0828_dmaqueue  *vbiq    = &dev->vbiq;
122
123	buf->vb.state = VIDEOBUF_QUEUED;
124	list_add_tail(&buf->vb.queue, &vbiq->active);
125}
126
127static void vbi_release(struct videobuf_queue *q, struct videobuf_buffer *vb)
128{
129	struct au0828_buffer *buf = container_of(vb, struct au0828_buffer, vb);
130	free_buffer(q, buf);
131}
132
133struct videobuf_queue_ops au0828_vbi_qops = {
134	.buf_setup    = vbi_setup,
135	.buf_prepare  = vbi_prepare,
136	.buf_queue    = vbi_queue,
137	.buf_release  = vbi_release,
138};
139