1 /*
2 em28xx-vbi.c - VBI driver for em28xx
3
4 Copyright (C) 2009 Devin Heitmueller <dheitmueller@kernellabs.com>
5
6 This work was sponsored by EyeMagnet Limited.
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/hardirq.h>
27 #include <linux/init.h>
28
29 #include "em28xx.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 static unsigned int vbi_debug;
36 module_param(vbi_debug, int, 0644);
37 MODULE_PARM_DESC(vbi_debug, "enable debug messages [vbi]");
38
39 #define dprintk(level, fmt, arg...) if (vbi_debug >= level) \
40 printk(KERN_DEBUG "%s: " fmt, dev->core->name , ## arg)
41
42 /* ------------------------------------------------------------------ */
43
44 static void
free_buffer(struct videobuf_queue * vq,struct em28xx_buffer * buf)45 free_buffer(struct videobuf_queue *vq, struct em28xx_buffer *buf)
46 {
47 struct em28xx_fh *fh = vq->priv_data;
48 struct em28xx *dev = fh->dev;
49 unsigned long flags = 0;
50 if (in_interrupt())
51 BUG();
52
53 /* We used to wait for the buffer to finish here, but this didn't work
54 because, as we were keeping the state as VIDEOBUF_QUEUED,
55 videobuf_queue_cancel marked it as finished for us.
56 (Also, it could wedge forever if the hardware was misconfigured.)
57
58 This should be safe; by the time we get here, the buffer isn't
59 queued anymore. If we ever start marking the buffers as
60 VIDEOBUF_ACTIVE, it won't be, though.
61 */
62 spin_lock_irqsave(&dev->slock, flags);
63 if (dev->isoc_ctl.vbi_buf == buf)
64 dev->isoc_ctl.vbi_buf = NULL;
65 spin_unlock_irqrestore(&dev->slock, flags);
66
67 videobuf_vmalloc_free(&buf->vb);
68 buf->vb.state = VIDEOBUF_NEEDS_INIT;
69 }
70
71 static int
vbi_setup(struct videobuf_queue * q,unsigned int * count,unsigned int * size)72 vbi_setup(struct videobuf_queue *q, unsigned int *count, unsigned int *size)
73 {
74 struct em28xx_fh *fh = q->priv_data;
75 struct em28xx *dev = fh->dev;
76
77 *size = dev->vbi_width * dev->vbi_height * 2;
78
79 if (0 == *count)
80 *count = vbibufs;
81 if (*count < 2)
82 *count = 2;
83 if (*count > 32)
84 *count = 32;
85 return 0;
86 }
87
88 static int
vbi_prepare(struct videobuf_queue * q,struct videobuf_buffer * vb,enum v4l2_field field)89 vbi_prepare(struct videobuf_queue *q, struct videobuf_buffer *vb,
90 enum v4l2_field field)
91 {
92 struct em28xx_fh *fh = q->priv_data;
93 struct em28xx *dev = fh->dev;
94 struct em28xx_buffer *buf = container_of(vb, struct em28xx_buffer, vb);
95 int rc = 0;
96
97 buf->vb.size = dev->vbi_width * dev->vbi_height * 2;
98
99 if (0 != buf->vb.baddr && buf->vb.bsize < buf->vb.size)
100 return -EINVAL;
101
102 buf->vb.width = dev->vbi_width;
103 buf->vb.height = dev->vbi_height;
104 buf->vb.field = field;
105
106 if (VIDEOBUF_NEEDS_INIT == buf->vb.state) {
107 rc = videobuf_iolock(q, &buf->vb, NULL);
108 if (rc < 0)
109 goto fail;
110 }
111
112 buf->vb.state = VIDEOBUF_PREPARED;
113 return 0;
114
115 fail:
116 free_buffer(q, buf);
117 return rc;
118 }
119
120 static void
vbi_queue(struct videobuf_queue * vq,struct videobuf_buffer * vb)121 vbi_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb)
122 {
123 struct em28xx_buffer *buf = container_of(vb,
124 struct em28xx_buffer,
125 vb);
126 struct em28xx_fh *fh = vq->priv_data;
127 struct em28xx *dev = fh->dev;
128 struct em28xx_dmaqueue *vbiq = &dev->vbiq;
129
130 buf->vb.state = VIDEOBUF_QUEUED;
131 list_add_tail(&buf->vb.queue, &vbiq->active);
132 }
133
vbi_release(struct videobuf_queue * q,struct videobuf_buffer * vb)134 static void vbi_release(struct videobuf_queue *q, struct videobuf_buffer *vb)
135 {
136 struct em28xx_buffer *buf = container_of(vb, struct em28xx_buffer, vb);
137 free_buffer(q, buf);
138 }
139
140 struct videobuf_queue_ops em28xx_vbi_qops = {
141 .buf_setup = vbi_setup,
142 .buf_prepare = vbi_prepare,
143 .buf_queue = vbi_queue,
144 .buf_release = vbi_release,
145 };
146