linux/drivers/media/usb/au0828/au0828-vbi.c

139 lines
3.8 KiB
C

/*
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,
};