xref: /linux/drivers/media/usb/em28xx/em28xx-vbi.c (revision 6ed7ffddcf61f668114edb676417e5fb33773b59)
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 int vbi_queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
45 			   unsigned int *nbuffers, unsigned int *nplanes,
46 			   unsigned int sizes[], void *alloc_ctxs[])
47 {
48 	struct em28xx *dev = vb2_get_drv_priv(vq);
49 	unsigned long size;
50 
51 	if (fmt)
52 		size = fmt->fmt.pix.sizeimage;
53 	else
54 		size = dev->vbi_width * dev->vbi_height * 2;
55 
56 	if (0 == *nbuffers)
57 		*nbuffers = 32;
58 	if (*nbuffers < 2)
59 		*nbuffers = 2;
60 	if (*nbuffers > 32)
61 		*nbuffers = 32;
62 
63 	*nplanes = 1;
64 	sizes[0] = size;
65 
66 	return 0;
67 }
68 
69 static int vbi_buffer_prepare(struct vb2_buffer *vb)
70 {
71 	struct em28xx        *dev = vb2_get_drv_priv(vb->vb2_queue);
72 	struct em28xx_buffer *buf = container_of(vb, struct em28xx_buffer, vb);
73 	unsigned long        size;
74 
75 	size = dev->vbi_width * dev->vbi_height * 2;
76 
77 	if (vb2_plane_size(vb, 0) < size) {
78 		printk(KERN_INFO "%s data will not fit into plane (%lu < %lu)\n",
79 		       __func__, vb2_plane_size(vb, 0), size);
80 		return -EINVAL;
81 	}
82 	vb2_set_plane_payload(&buf->vb, 0, size);
83 
84 	return 0;
85 }
86 
87 static void
88 vbi_buffer_queue(struct vb2_buffer *vb)
89 {
90 	struct em28xx *dev = vb2_get_drv_priv(vb->vb2_queue);
91 	struct em28xx_buffer *buf = container_of(vb, struct em28xx_buffer, vb);
92 	struct em28xx_dmaqueue *vbiq = &dev->vbiq;
93 	unsigned long flags = 0;
94 
95 	buf->mem = vb2_plane_vaddr(vb, 0);
96 	buf->length = vb2_plane_size(vb, 0);
97 
98 	spin_lock_irqsave(&dev->slock, flags);
99 	list_add_tail(&buf->list, &vbiq->active);
100 	spin_unlock_irqrestore(&dev->slock, flags);
101 }
102 
103 
104 struct vb2_ops em28xx_vbi_qops = {
105 	.queue_setup    = vbi_queue_setup,
106 	.buf_prepare    = vbi_buffer_prepare,
107 	.buf_queue      = vbi_buffer_queue,
108 	.start_streaming = em28xx_start_analog_streaming,
109 	.stop_streaming = em28xx_stop_vbi_streaming,
110 	.wait_prepare   = vb2_ops_wait_prepare,
111 	.wait_finish    = vb2_ops_wait_finish,
112 };
113