diff options
Diffstat (limited to 'drivers/media/usb/em28xx/em28xx-vbi.c')
| -rw-r--r-- | drivers/media/usb/em28xx/em28xx-vbi.c | 145 |
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, +}; |