V4L/DVB: Add closed captioning support for the HVR-950q

Add NTSC closed captioning support for au0828 based products.  Note that this
also required reworking the locking to support streaming on both the video and
VBI devices (the logic for which I copied from my changes made to the em28xx
several months ago).

This work was sponsored by GetWellNetwork Inc.

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/au0828/Makefile

@@ -1,4 +1,4 @@
-au0828-objs	:= au0828-core.o au0828-i2c.o au0828-cards.o au0828-dvb.o au0828-video.o
+au0828-objs	:= au0828-core.o au0828-i2c.o au0828-cards.o au0828-dvb.o au0828-video.o au0828-vbi.o
 
 obj-$(CONFIG_VIDEO_AU0828) += au0828.o
 

drivers/media/video/au0828/au0828-vbi.c

@@ -0,0 +1,138 @@
+/*
+   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,
+};