From: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxxxxxxxxxxxxx>
Provide v4l2_subdevs with v4l2_event support. Subdev drivers only need very
little to support events.
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: David Cohen <david.cohen@xxxxxxxxx>
Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
---
Documentation/video4linux/v4l2-framework.txt | 18 ++++++
drivers/media/video/v4l2-subdev.c | 75 +++++++++++++++++++++++++-
include/media/v4l2-subdev.h | 10 ++++
3 files changed, 102 insertions(+), 1 deletions(-)
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt
index f683f63..4db1def 100644
--- a/Documentation/video4linux/v4l2-framework.txt
+++ b/Documentation/video4linux/v4l2-framework.txt
@@ -352,6 +352,24 @@ 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
----------------------
diff --git a/drivers/media/video/v4l2-subdev.c b/drivers/media/video/v4l2-subdev.c
index fc57ce7..fbccefd 100644
--- a/drivers/media/video/v4l2-subdev.c
+++ b/drivers/media/video/v4l2-subdev.c
@@ -20,27 +20,69 @@
* 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->initialized)
return -EAGAIN;
+ 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;
}
@@ -48,6 +90,7 @@ 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:
@@ -71,6 +114,18 @@ 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;
}
@@ -84,11 +139,29 @@ 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)
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index 90022f5..68cbe48 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -37,6 +37,8 @@
struct v4l2_device;
struct v4l2_ctrl_handler;
+struct v4l2_event_subscription;
+struct v4l2_fh;
struct v4l2_subdev;
struct tuner_setup;
@@ -165,6 +167,10 @@ 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.
@@ -424,6 +430,8 @@ struct v4l2_subdev_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.
@@ -446,6 +454,8 @@ struct v4l2_subdev {
/* subdev device node */
struct video_device devnode;
unsigned int initialized;
+ /* number of events to be allocated on open */
+ unsigned int nevents;
};
#define vdev_to_v4l2_subdev(vdev) \
--
1.7.2.2
--
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