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path: root/drivers/media/usb/em28xx/em28xx-vbi.c
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Diffstat (limited to 'drivers/media/usb/em28xx/em28xx-vbi.c')
-rw-r--r--drivers/media/usb/em28xx/em28xx-vbi.c145
1 files changed, 145 insertions, 0 deletions
diff --git a/drivers/media/usb/em28xx/em28xx-vbi.c b/drivers/media/usb/em28xx/em28xx-vbi.c
new file mode 100644
index 000000000000..2b4c9cba2d67
--- /dev/null
+++ b/drivers/media/usb/em28xx/em28xx-vbi.c
@@ -0,0 +1,145 @@
+/*
+ em28xx-vbi.c - VBI driver for em28xx
+
+ Copyright (C) 2009 Devin Heitmueller <dheitmueller@kernellabs.com>
+
+ This work was sponsored by EyeMagnet Limited.
+
+ 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/hardirq.h>
+#include <linux/init.h>
+
+#include "em28xx.h"
+
+static unsigned int vbibufs = 5;
+module_param(vbibufs, int, 0644);
+MODULE_PARM_DESC(vbibufs, "number of vbi buffers, range 2-32");
+
+static unsigned int vbi_debug;
+module_param(vbi_debug, int, 0644);
+MODULE_PARM_DESC(vbi_debug, "enable debug messages [vbi]");
+
+#define dprintk(level, fmt, arg...) if (vbi_debug >= level) \
+ printk(KERN_DEBUG "%s: " fmt, dev->core->name , ## arg)
+
+/* ------------------------------------------------------------------ */
+
+static void
+free_buffer(struct videobuf_queue *vq, struct em28xx_buffer *buf)
+{
+ struct em28xx_fh *fh = vq->priv_data;
+ struct em28xx *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 em28xx_fh *fh = q->priv_data;
+ struct em28xx *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 em28xx_fh *fh = q->priv_data;
+ struct em28xx *dev = fh->dev;
+ struct em28xx_buffer *buf = container_of(vb, struct em28xx_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 em28xx_buffer *buf = container_of(vb,
+ struct em28xx_buffer,
+ vb);
+ struct em28xx_fh *fh = vq->priv_data;
+ struct em28xx *dev = fh->dev;
+ struct em28xx_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 em28xx_buffer *buf = container_of(vb, struct em28xx_buffer, vb);
+ free_buffer(q, buf);
+}
+
+struct videobuf_queue_ops em28xx_vbi_qops = {
+ .buf_setup = vbi_setup,
+ .buf_prepare = vbi_prepare,
+ .buf_queue = vbi_queue,
+ .buf_release = vbi_release,
+};