[media] v4l: subdev: Events support

Provide v4l2_subdevs with v4l2_event support. Subdev drivers only need very
little to support events.

Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: David Cohen <dacohen@gmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Sakari Ailus 2010-03-03 12:49:38 -03:00 committed by Mauro Carvalho Chehab
parent ea8aa4349e
commit 02adb1cc76
3 changed files with 105 additions and 1 deletions

View file

@ -350,6 +350,24 @@ VIDIOC_TRY_EXT_CTRLS
controls can be also be accessed through one (or several) V4L2 device
nodes.
VIDIOC_DQEVENT
VIDIOC_SUBSCRIBE_EVENT
VIDIOC_UNSUBSCRIBE_EVENT
The events ioctls are identical to the ones defined in V4L2. They
behave identically, with the only exception that they deal only with
events generated by the sub-device. Depending on the driver, those
events can also be reported by one (or several) V4L2 device nodes.
Sub-device drivers that want to use events need to set the
V4L2_SUBDEV_USES_EVENTS v4l2_subdev::flags and initialize
v4l2_subdev::nevents to events queue depth before registering the
sub-device. After registration events can be queued as usual on the
v4l2_subdev::devnode device node.
To properly support events, the poll() file operation is also
implemented.
I2C sub-device drivers
----------------------

View file

@ -20,21 +20,66 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/types.h>
#include <linux/ioctl.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/videodev2.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>
static int subdev_open(struct file *file)
{
struct video_device *vdev = video_devdata(file);
struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
struct v4l2_fh *vfh;
int ret;
if (sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS) {
vfh = kzalloc(sizeof(*vfh), GFP_KERNEL);
if (vfh == NULL)
return -ENOMEM;
ret = v4l2_fh_init(vfh, vdev);
if (ret)
goto err;
ret = v4l2_event_init(vfh);
if (ret)
goto err;
ret = v4l2_event_alloc(vfh, sd->nevents);
if (ret)
goto err;
v4l2_fh_add(vfh);
file->private_data = vfh;
}
return 0;
err:
if (vfh != NULL) {
v4l2_fh_exit(vfh);
kfree(vfh);
}
return ret;
}
static int subdev_close(struct file *file)
{
struct v4l2_fh *vfh = file->private_data;
if (vfh != NULL) {
v4l2_fh_del(vfh);
v4l2_fh_exit(vfh);
kfree(vfh);
}
return 0;
}
@ -42,6 +87,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
{
struct video_device *vdev = video_devdata(file);
struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
struct v4l2_fh *fh = file->private_data;
switch (cmd) {
case VIDIOC_QUERYCTRL:
@ -65,6 +111,18 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
case VIDIOC_TRY_EXT_CTRLS:
return v4l2_subdev_try_ext_ctrls(sd, arg);
case VIDIOC_DQEVENT:
if (!(sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS))
return -ENOIOCTLCMD;
return v4l2_event_dequeue(fh, arg, file->f_flags & O_NONBLOCK);
case VIDIOC_SUBSCRIBE_EVENT:
return v4l2_subdev_call(sd, core, subscribe_event, fh, arg);
case VIDIOC_UNSUBSCRIBE_EVENT:
return v4l2_subdev_call(sd, core, unsubscribe_event, fh, arg);
default:
return -ENOIOCTLCMD;
}
@ -78,11 +136,29 @@ static long subdev_ioctl(struct file *file, unsigned int cmd,
return video_usercopy(file, cmd, arg, subdev_do_ioctl);
}
static unsigned int subdev_poll(struct file *file, poll_table *wait)
{
struct video_device *vdev = video_devdata(file);
struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
struct v4l2_fh *fh = file->private_data;
if (!(sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS))
return POLLERR;
poll_wait(file, &fh->events->wait, wait);
if (v4l2_event_pending(fh))
return POLLPRI;
return 0;
}
const struct v4l2_file_operations v4l2_subdev_fops = {
.owner = THIS_MODULE,
.open = subdev_open,
.unlocked_ioctl = subdev_ioctl,
.release = subdev_close,
.poll = subdev_poll,
};
void v4l2_subdev_init(struct v4l2_subdev *sd, const struct v4l2_subdev_ops *ops)

View file

@ -37,6 +37,8 @@
struct v4l2_device;
struct v4l2_ctrl_handler;
struct v4l2_event_subscription;
struct v4l2_fh;
struct v4l2_subdev;
struct tuner_setup;
@ -161,6 +163,10 @@ struct v4l2_subdev_core_ops {
int (*s_power)(struct v4l2_subdev *sd, int on);
int (*interrupt_service_routine)(struct v4l2_subdev *sd,
u32 status, bool *handled);
int (*subscribe_event)(struct v4l2_subdev *sd, struct v4l2_fh *fh,
struct v4l2_event_subscription *sub);
int (*unsubscribe_event)(struct v4l2_subdev *sd, struct v4l2_fh *fh,
struct v4l2_event_subscription *sub);
};
/* s_mode: switch the tuner to a specific tuner mode. Replacement of s_radio.
@ -437,6 +443,8 @@ struct v4l2_subdev_internal_ops {
#define V4L2_SUBDEV_FL_IS_SPI (1U << 1)
/* Set this flag if this subdev needs a device node. */
#define V4L2_SUBDEV_FL_HAS_DEVNODE (1U << 2)
/* Set this flag if this subdev generates events. */
#define V4L2_SUBDEV_FL_HAS_EVENTS (1U << 3)
/* Each instance of a subdev driver should create this struct, either
stand-alone or embedded in a larger struct.
@ -460,6 +468,8 @@ struct v4l2_subdev {
void *host_priv;
/* subdev device node */
struct video_device devnode;
/* number of events to be allocated on open */
unsigned int nevents;
};
#define vdev_to_v4l2_subdev(vdev) \