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
31 static unsigned int vbibufs = 5;
32 module_param(vbibufs, int, 0644);
33 MODULE_PARM_DESC(vbibufs, "number of vbi buffers, range 2-32");
34
35 /* ------------------------------------------------------------------ */
36
37 static void
free_buffer(struct videobuf_queue * vq,struct au0828_buffer * buf)38 free_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
64 static int
vbi_setup(struct videobuf_queue * q,unsigned int * count,unsigned int * size)65 vbi_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
81 static int
vbi_prepare(struct videobuf_queue * q,struct videobuf_buffer * vb,enum v4l2_field field)82 vbi_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
108 fail:
109 free_buffer(q, buf);
110 return rc;
111 }
112
113 static void
vbi_queue(struct videobuf_queue * vq,struct videobuf_buffer * vb)114 vbi_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
vbi_release(struct videobuf_queue * q,struct videobuf_buffer * vb)127 static 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
133 struct 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