V4L2 file handles and event interface

PATCH In review Sakari Ailus 3 participants 11 messages Feb 24, 2010 – Mar 9, 2010

Subsystems (2)

Documentation Media (V4L/DVB)

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Sakari Ailus

author

2010-02-24 22:46 UTC #0 lore raw

v8 cover V4L2 file handles and event interface

Hi,

Here's the tenth version of the V4L2 file handle and event interface patchset.

The patchset has been tested with the OMAP 3 ISP driver. Patches for OMAP 3 ISP are not part of this patchset but are available in Gitorious (branch is called event):

git://gitorious.org/omap3camera/mainline.git event

The patchset I'm posting now is against the v4l-dvb tree instead of linux-omap. The omap3camera tree thus has a slightly different version of these patches (just Makefiles) due to different baselines.

Some more comments from Hans and Randy. There are only improvements in documentation this time.

Comments are welcome as always.

Cheers,

Signature · 2 lines

Sakari Ailus
[email protected]

Sakari Ailus

author

2010-02-24 22:46 UTC #1 lore raw

PATCH v8 1/6 V4L: File handles

This patch adds a list of v4l2_fh structures to every video_device. It allows using file handle related information in V4L2. The event interface is one example of such use.

Video device drivers should use the v4l2_fh pointer as their file->private_data.

Signed-off-by Sakari Ailus <[email protected]>

---
 drivers/media/video/Makefile   |    2 +-
 drivers/media/video/v4l2-dev.c |    4 ++
 drivers/media/video/v4l2-fh.c  |   66 ++++++++++++++++++++++++++++++++++++++++
 include/media/v4l2-dev.h       |    5 +++
 include/media/v4l2-fh.h        |   42 +++++++++++++++++++++++++
 5 files changed, 118 insertions(+), 1 deletions(-)
 create mode 100644 drivers/media/video/v4l2-fh.c
 create mode 100644 include/media/v4l2-fh.h

drivers/media/video/Makefile +1 -1

index 5163289..14bf69a 100644
@@ -10,7 +10,7 @@ stkwebcam-objs	:=	stk-webcam.o stk-sensor.o
 
 omap2cam-objs	:=	omap24xxcam.o omap24xxcam-dma.o
 
-videodev-objs	:=	v4l2-dev.o v4l2-ioctl.o v4l2-device.o
+videodev-objs	:=	v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o
 
 # V4L2 core modules

drivers/media/video/v4l2-dev.c +4 -0

index 7090699..65a7b30 100644
@@ -421,6 +421,10 @@ static int __video_register_device(struct video_device *vdev, int type, int nr,
 	if (!vdev->release)
 		return -EINVAL;
 
+	/* v4l2_fh support */
+	spin_lock_init(&vdev->fh_lock);
+	INIT_LIST_HEAD(&vdev->fh_list);
+
 	/* Part 1: check device type */
 	switch (type) {
 	case VFL_TYPE_GRABBER:

drivers/media/video/v4l2-fh.c new file +66 -0

66 lines not on this page · raw message

include/media/v4l2-dev.h +5 -0

index 2dee938..bebe44b 100644
@@ -32,6 +32,7 @@ struct v4l2_device;
    Drivers can clear this flag if they want to block all future
    device access. It is cleared by video_unregister_device. */
 #define V4L2_FL_REGISTERED	(0)
+#define V4L2_FL_USES_V4L2_FH	(1)
 
 struct v4l2_file_operations {
 	struct module *owner;

@@ -77,6 +78,10 @@ struct video_device
 	/* attribute to differentiate multiple indices on one physical device */
 	int index;
 
+	/* V4L2 file handles */
+	spinlock_t		fh_lock; /* Lock for all v4l2_fhs */
+	struct list_head	fh_list; /* List of struct v4l2_fh */
+
 	int debug;			/* Activates debug level*/
 
 	/* Video standard vars */

include/media/v4l2-fh.h new file +42 -0

42 lines not on this page · raw message

Signature · 1 line

1.5.6.5

Sakari Ailus

author

2010-02-24 22:46 UTC #2 lore raw

PATCH v8 2/6 V4L: File handles: Add documentation

In reply to Sakari Ailus

Add documentation on using V4L2 file handles (v4l2_fh) in V4L2 drivers.

Signed-off-by Sakari Ailus <[email protected]>

---
 Documentation/video4linux/v4l2-framework.txt |   37 ++++++++++++++++++++++++++
 1 files changed, 37 insertions(+), 0 deletions(-)

Documentation/video4linux/v4l2-framework.txt +37 -0

index 74d677c..bfaf0c5 100644
@@ -695,3 +695,40 @@ The better way to understand it is to take a look at vivi driver. One
 of the main reasons for vivi is to be a videobuf usage example. the
 vivi_thread_tick() does the task that the IRQ callback would do on PCI
 drivers (or the irq callback on USB).
+
+struct v4l2_fh
+--------------
+
+struct v4l2_fh provides a way to easily keep file handle specific data
+that is used by the V4L2 framework.
+
+struct v4l2_fh is allocated as a part of the driver's own file handle
+structure and is set to file->private_data in the driver's open
+function by the driver. Drivers can extract their own file handle
+structure by using the container_of macro.
+
+Useful functions:
+
+- v4l2_fh_init()
+
+  Initialise the file handle. This *MUST* be performed in the driver's
+  v4l2_file_operations->open() handler.
+
+- v4l2_fh_add()
+
+  Add a v4l2_fh to video_device file handle list. May be called after
+  initialising the file handle.
+
+- v4l2_fh_del()
+
+  Unassociate the file handle from video_device(). The file handle
+  exit function may now be called.
+
+- v4l2_fh_exit()
+
+  Uninitialise the file handle. After uninitialisation the v4l2_fh
+  memory can be freed.
+
+The users of v4l2_fh know whether a driver uses v4l2_fh as its
+file->private_data pointer by testing the V4L2_FL_USES_V4L2_FH bit in
+video_device->flags.

Signature · 1 line

1.5.6.5

Sakari Ailus

author

2010-02-24 22:46 UTC #3 lore raw

PATCH v8 3/6 V4L: Events: Add new ioctls for events

In reply to Sakari Ailus

This patch adds a set of new ioctls to the V4L2 API. The ioctls conform to V4L2 Events RFC version 2.3:

<URL:http://www.spinics.net/lists/linux-media/msg12033.html>

Signed-off-by Sakari Ailus <[email protected]>

---
 drivers/media/video/v4l2-compat-ioctl32.c |    3 +++
 drivers/media/video/v4l2-ioctl.c          |    3 +++
 include/linux/videodev2.h                 |   26 ++++++++++++++++++++++++++
 3 files changed, 32 insertions(+), 0 deletions(-)

drivers/media/video/v4l2-compat-ioctl32.c +3 -0

index f77f84b..9004a5f 100644
@@ -1086,6 +1086,9 @@ long v4l2_compat_ioctl32(struct file *file, unsigned int cmd, unsigned long arg)
 	case VIDIOC_QUERY_DV_PRESET:
 	case VIDIOC_S_DV_TIMINGS:
 	case VIDIOC_G_DV_TIMINGS:
+	case VIDIOC_DQEVENT:
+	case VIDIOC_SUBSCRIBE_EVENT:
+	case VIDIOC_UNSUBSCRIBE_EVENT:
 		ret = do_video_ioctl(file, cmd, arg);
 		break;

drivers/media/video/v4l2-ioctl.c +3 -0

index 4b11257..34c7d6e 100644
@@ -290,6 +290,9 @@ static const char *v4l2_ioctls[] = {
 	[_IOC_NR(VIDIOC_QUERY_DV_PRESET)]  = "VIDIOC_QUERY_DV_PRESET",
 	[_IOC_NR(VIDIOC_S_DV_TIMINGS)]     = "VIDIOC_S_DV_TIMINGS",
 	[_IOC_NR(VIDIOC_G_DV_TIMINGS)]     = "VIDIOC_G_DV_TIMINGS",
+	[_IOC_NR(VIDIOC_DQEVENT)]	   = "VIDIOC_DQEVENT",
+	[_IOC_NR(VIDIOC_SUBSCRIBE_EVENT)]  = "VIDIOC_SUBSCRIBE_EVENT",
+	[_IOC_NR(VIDIOC_UNSUBSCRIBE_EVENT)] = "VIDIOC_UNSUBSCRIBE_EVENT",
 };
 #define V4L2_IOCTLS ARRAY_SIZE(v4l2_ioctls)

include/linux/videodev2.h +26 -0

index 3c26560..d3b1446 100644
@@ -1622,6 +1622,29 @@ struct v4l2_streamparm {
 };
 
 /*
+ *	E V E N T S
+ */
+
+struct v4l2_event {
+	__u32				type;
+	union {
+		__u8			data[64];
+	} u;
+	__u32				pending;
+	__u32				sequence;
+	struct timespec			timestamp;
+	__u32				reserved[9];
+};
+
+struct v4l2_event_subscription {
+	__u32				type;
+	__u32				reserved[7];
+};
+
+#define V4L2_EVENT_ALL				0
+#define V4L2_EVENT_PRIVATE_START		0x08000000
+
+/*
  *	A D V A N C E D   D E B U G G I N G
  *
  *	NOTE: EXPERIMENTAL API, NEVER RELY ON THIS IN APPLICATIONS!

@@ -1743,6 +1766,9 @@ struct v4l2_dbg_chip_ident {
 #define	VIDIOC_QUERY_DV_PRESET	_IOR('V',  86, struct v4l2_dv_preset)
 #define	VIDIOC_S_DV_TIMINGS	_IOWR('V', 87, struct v4l2_dv_timings)
 #define	VIDIOC_G_DV_TIMINGS	_IOWR('V', 88, struct v4l2_dv_timings)
+#define	VIDIOC_DQEVENT		 _IOR('V', 89, struct v4l2_event)
+#define	VIDIOC_SUBSCRIBE_EVENT	 _IOW('V', 90, struct v4l2_event_subscription)
+#define	VIDIOC_UNSUBSCRIBE_EVENT _IOW('V', 91, struct v4l2_event_subscription)
 
 /* Reminder: when adding new ioctls please add support for them to
    drivers/media/video/v4l2-compat-ioctl32.c as well! */

Signature · 1 line

1.5.6.5

Sakari Ailus

author

2010-02-24 22:46 UTC #4 lore raw

PATCH v8 4/6 V4L: Events: Add backend

In reply to Sakari Ailus

Add event handling backend to V4L2. The backend handles event subscription and delivery to file handles. Event subscriptions are based on file handle. Events may be delivered to all subscribed file handles on a device independent of where they originate from.

Signed-off-by Sakari Ailus <[email protected]>

---
 drivers/media/video/Makefile     |    3 +-
 drivers/media/video/v4l2-event.c |  289 ++++++++++++++++++++++++++++++++++++++
 drivers/media/video/v4l2-fh.c    |    6 +-
 include/media/v4l2-event.h       |   67 +++++++++
 include/media/v4l2-fh.h          |    2 +
 5 files changed, 365 insertions(+), 2 deletions(-)
 create mode 100644 drivers/media/video/v4l2-event.c
 create mode 100644 include/media/v4l2-event.h

drivers/media/video/Makefile +2 -1

index 14bf69a..b84abfe 100644
@@ -10,7 +10,8 @@ stkwebcam-objs	:=	stk-webcam.o stk-sensor.o
 
 omap2cam-objs	:=	omap24xxcam.o omap24xxcam-dma.o
 
-videodev-objs	:=	v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o
+videodev-objs	:=	v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o \
+			v4l2-event.o
 
 # V4L2 core modules

drivers/media/video/v4l2-event.c new file +289 -0

289 lines not on this page · raw message

drivers/media/video/v4l2-fh.c +5 -1

index 93ea0af..aab2fb6 100644
@@ -25,6 +25,8 @@
 #include <linux/bitops.h>
 #include <media/v4l2-dev.h>
 #include <media/v4l2-fh.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-ioctl.h>
 
 int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
 {

@@ -32,7 +34,7 @@ int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
 	INIT_LIST_HEAD(&fh->list);
 	set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags);
 
-	return 0;
+	return v4l2_event_init(fh);
 }
 EXPORT_SYMBOL_GPL(v4l2_fh_init);

@@ -62,5 +64,7 @@ void v4l2_fh_exit(struct v4l2_fh *fh)
 		return;
 
 	fh->vdev = NULL;
+
+	v4l2_event_free(fh);
 }
 EXPORT_SYMBOL_GPL(v4l2_fh_exit);

include/media/v4l2-event.h new file +67 -0

67 lines not on this page · raw message

include/media/v4l2-fh.h +2 -0

index 410e86c..1d48c15 100644
@@ -28,10 +28,12 @@
 #include <linux/list.h>
 
 struct video_device;
+struct v4l2_events;
 
 struct v4l2_fh {
 	struct list_head	list;
 	struct video_device	*vdev;
+	struct v4l2_events      *events; /* events, pending and subscribed */
 };
 
 int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);

Signature · 1 line

1.5.6.5

Sakari Ailus

2010-03-01 08:17 UTC #5 lore raw

Re: [PATCH v8 4/6] V4L: Events: Add backend

Quoted 4 lines · Sakari Ailus

Add event handling backend to V4L2. The backend handles event subscription and delivery to file handles. Event subscriptions are based on file handle. Events may be delivered to all subscribed file handles on a device independent of where they originate from.

Hi,

Some style problems accidentally slipped into this one. I'm not resending the whole set, just the broken patch, now v8.1.

Signature · 2 lines

Sakari Ailus
[email protected]

Sakari Ailus

author

2010-03-01 08:19 UTC #6 lore raw

PATCH v8 4/6 V4L: Events: Add backend

In reply to Sakari Ailus

Signed-off-by Sakari Ailus <[email protected]>

---
 drivers/media/video/Makefile     |    3 +-
 drivers/media/video/v4l2-event.c |  289 ++++++++++++++++++++++++++++++++++++++
 drivers/media/video/v4l2-fh.c    |    6 +-
 include/media/v4l2-event.h       |   67 +++++++++
 include/media/v4l2-fh.h          |    2 +
 5 files changed, 365 insertions(+), 2 deletions(-)
 create mode 100644 drivers/media/video/v4l2-event.c
 create mode 100644 include/media/v4l2-event.h

drivers/media/video/Makefile +2 -1

index 14bf69a..b84abfe 100644
@@ -10,7 +10,8 @@ stkwebcam-objs	:=	stk-webcam.o stk-sensor.o
 
 omap2cam-objs	:=	omap24xxcam.o omap24xxcam-dma.o
 
-videodev-objs	:=	v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o
+videodev-objs	:=	v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o \
+			v4l2-event.o
 
 # V4L2 core modules

drivers/media/video/v4l2-event.c new file +289 -0

289 lines not on this page · raw message

drivers/media/video/v4l2-fh.c +5 -1

index 93ea0af..aab2fb6 100644
@@ -25,6 +25,8 @@
 #include <linux/bitops.h>
 #include <media/v4l2-dev.h>
 #include <media/v4l2-fh.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-ioctl.h>
 
 int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
 {

@@ -32,7 +34,7 @@ int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
 	INIT_LIST_HEAD(&fh->list);
 	set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags);
 
-	return 0;
+	return v4l2_event_init(fh);
 }
 EXPORT_SYMBOL_GPL(v4l2_fh_init);

@@ -62,5 +64,7 @@ void v4l2_fh_exit(struct v4l2_fh *fh)
 		return;
 
 	fh->vdev = NULL;
+
+	v4l2_event_free(fh);
 }
 EXPORT_SYMBOL_GPL(v4l2_fh_exit);

include/media/v4l2-event.h new file +67 -0

67 lines not on this page · raw message

include/media/v4l2-fh.h +2 -0

index 410e86c..1d48c15 100644
@@ -28,10 +28,12 @@
 #include <linux/list.h>
 
 struct video_device;
+struct v4l2_events;
 
 struct v4l2_fh {
 	struct list_head	list;
 	struct video_device	*vdev;
+	struct v4l2_events      *events; /* events, pending and subscribed */
 };
 
 int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);

Signature · 1 line

1.5.6.5

Sakari Ailus

author

2010-02-24 22:46 UTC #7 lore raw

PATCH v8 5/6 V4L: Events: Support event handling in do_ioctl

In reply to Sakari Ailus

Add support for event handling to do_ioctl.

Signed-off-by Sakari Ailus <[email protected]>

---
 drivers/media/video/v4l2-fh.c    |   11 +++++++-
 drivers/media/video/v4l2-ioctl.c |   50 ++++++++++++++++++++++++++++++++++++++
 include/media/v4l2-ioctl.h       |    7 +++++
 3 files changed, 67 insertions(+), 1 deletions(-)

drivers/media/video/v4l2-fh.c +10 -1

index aab2fb6..1423c44 100644
@@ -34,7 +34,16 @@ int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
 	INIT_LIST_HEAD(&fh->list);
 	set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags);
 
-	return v4l2_event_init(fh);
+	/*
+	 * fh->events only needs to be initialized if the driver
+	 * supports the VIDIOC_SUBSCRIBE_EVENT ioctl.
+	 */
+	if (vdev->ioctl_ops && vdev->ioctl_ops->vidioc_subscribe_event)
+		return v4l2_event_init(fh);
+	else
+		fh->events = NULL;
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(v4l2_fh_init);

drivers/media/video/v4l2-ioctl.c +50 -0

63 lines not on this page · raw message

include/media/v4l2-ioctl.h +7 -0

index e8ba0f2..06daa6e 100644
@@ -21,6 +21,8 @@
 #include <linux/videodev2.h>
 #endif
 
+struct v4l2_fh;
+
 struct v4l2_ioctl_ops {
 	/* ioctl callbacks */

@@ -254,6 +256,11 @@ struct v4l2_ioctl_ops {
 	int (*vidioc_g_dv_timings) (struct file *file, void *fh,
 				    struct v4l2_dv_timings *timings);
 
+	int (*vidioc_subscribe_event)  (struct v4l2_fh *fh,
+					struct v4l2_event_subscription *sub);
+	int (*vidioc_unsubscribe_event)(struct v4l2_fh *fh,
+					struct v4l2_event_subscription *sub);
+
 	/* For other private ioctls */
 	long (*vidioc_default)	       (struct file *file, void *fh,
 					int cmd, void *arg);

Signature · 1 line

1.5.6.5

Sakari Ailus

author

2010-02-24 22:46 UTC #8 lore raw

PATCH v8 6/6 V4L: Events: Add documentation

In reply to Sakari Ailus

Add documentation on how to use V4L2 events, both for V4L2 drivers and for V4L2 applications.

Signed-off-by Sakari Ailus <[email protected]>

---
 Documentation/DocBook/media-entities.tmpl          |    9 ++
 Documentation/DocBook/v4l/dev-event.xml            |   31 +++++
 Documentation/DocBook/v4l/v4l2.xml                 |    3 +
 Documentation/DocBook/v4l/vidioc-dqevent.xml       |  124 ++++++++++++++++++++
 .../DocBook/v4l/vidioc-subscribe-event.xml         |  104 ++++++++++++++++
 Documentation/video4linux/v4l2-framework.txt       |   60 ++++++++++
 6 files changed, 331 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/DocBook/v4l/dev-event.xml
 create mode 100644 Documentation/DocBook/v4l/vidioc-dqevent.xml
 create mode 100644 Documentation/DocBook/v4l/vidioc-subscribe-event.xml

Documentation/DocBook/media-entities.tmpl +9 -0

index c725cb8..770be3c 100644
@@ -17,6 +17,7 @@
 <!ENTITY VIDIOC-DBG-G-REGISTER "<link linkend='vidioc-dbg-g-register'><constant>VIDIOC_DBG_G_REGISTER</constant></link>">
 <!ENTITY VIDIOC-DBG-S-REGISTER "<link linkend='vidioc-dbg-g-register'><constant>VIDIOC_DBG_S_REGISTER</constant></link>">
 <!ENTITY VIDIOC-DQBUF "<link linkend='vidioc-qbuf'><constant>VIDIOC_DQBUF</constant></link>">
+<!ENTITY VIDIOC-DQEVENT "<link linkend='vidioc-dqevent'><constant>VIDIOC_DQEVENT</constant></link>">
 <!ENTITY VIDIOC-ENCODER-CMD "<link linkend='vidioc-encoder-cmd'><constant>VIDIOC_ENCODER_CMD</constant></link>">
 <!ENTITY VIDIOC-ENUMAUDIO "<link linkend='vidioc-enumaudio'><constant>VIDIOC_ENUMAUDIO</constant></link>">
 <!ENTITY VIDIOC-ENUMAUDOUT "<link linkend='vidioc-enumaudioout'><constant>VIDIOC_ENUMAUDOUT</constant></link>">

@@ -60,6 +61,7 @@
 <!ENTITY VIDIOC-REQBUFS "<link linkend='vidioc-reqbufs'><constant>VIDIOC_REQBUFS</constant></link>">
 <!ENTITY VIDIOC-STREAMOFF "<link linkend='vidioc-streamon'><constant>VIDIOC_STREAMOFF</constant></link>">
 <!ENTITY VIDIOC-STREAMON "<link linkend='vidioc-streamon'><constant>VIDIOC_STREAMON</constant></link>">
+<!ENTITY VIDIOC-SUBSCRIBE-EVENT "<link linkend='vidioc-subscribe-event'><constant>VIDIOC_SUBSCRIBE_EVENT</constant></link>">
 <!ENTITY VIDIOC-S-AUDIO "<link linkend='vidioc-g-audio'><constant>VIDIOC_S_AUDIO</constant></link>">
 <!ENTITY VIDIOC-S-AUDOUT "<link linkend='vidioc-g-audioout'><constant>VIDIOC_S_AUDOUT</constant></link>">
 <!ENTITY VIDIOC-S-CROP "<link linkend='vidioc-g-crop'><constant>VIDIOC_S_CROP</constant></link>">

@@ -141,6 +143,8 @@
 <!ENTITY v4l2-enc-idx "struct&nbsp;<link linkend='v4l2-enc-idx'>v4l2_enc_idx</link>">
 <!ENTITY v4l2-enc-idx-entry "struct&nbsp;<link linkend='v4l2-enc-idx-entry'>v4l2_enc_idx_entry</link>">
 <!ENTITY v4l2-encoder-cmd "struct&nbsp;<link linkend='v4l2-encoder-cmd'>v4l2_encoder_cmd</link>">
+<!ENTITY v4l2-event "struct&nbsp;<link linkend='v4l2-event'>v4l2_event</link>">
+<!ENTITY v4l2-event-subscription "struct&nbsp;<link linkend='v4l2-event-subscription'>v4l2_event_subscription</link>">
 <!ENTITY v4l2-ext-control "struct&nbsp;<link linkend='v4l2-ext-control'>v4l2_ext_control</link>">
 <!ENTITY v4l2-ext-controls "struct&nbsp;<link linkend='v4l2-ext-controls'>v4l2_ext_controls</link>">
 <!ENTITY v4l2-fmtdesc "struct&nbsp;<link linkend='v4l2-fmtdesc'>v4l2_fmtdesc</link>">

@@ -200,6 +204,7 @@
 <!ENTITY sub-controls SYSTEM "v4l/controls.xml">
 <!ENTITY sub-dev-capture SYSTEM "v4l/dev-capture.xml">
 <!ENTITY sub-dev-codec SYSTEM "v4l/dev-codec.xml">
+<!ENTITY sub-dev-event SYSTEM "v4l/dev-event.xml">
 <!ENTITY sub-dev-effect SYSTEM "v4l/dev-effect.xml">
 <!ENTITY sub-dev-osd SYSTEM "v4l/dev-osd.xml">
 <!ENTITY sub-dev-output SYSTEM "v4l/dev-output.xml">

@@ -292,6 +297,8 @@
 <!ENTITY sub-v4l2grab-c SYSTEM "v4l/v4l2grab.c.xml">
 <!ENTITY sub-videodev2-h SYSTEM "v4l/videodev2.h.xml">
 <!ENTITY sub-v4l2 SYSTEM "v4l/v4l2.xml">
+<!ENTITY sub-dqevent SYSTEM "v4l/vidioc-dqevent.xml">
+<!ENTITY sub-subscribe-event SYSTEM "v4l/vidioc-subscribe-event.xml">
 <!ENTITY sub-intro SYSTEM "dvb/intro.xml">
 <!ENTITY sub-frontend SYSTEM "dvb/frontend.xml">
 <!ENTITY sub-dvbproperty SYSTEM "dvb/dvbproperty.xml">

@@ -381,3 +388,5 @@
 <!ENTITY reqbufs SYSTEM "v4l/vidioc-reqbufs.xml">
 <!ENTITY s-hw-freq-seek SYSTEM "v4l/vidioc-s-hw-freq-seek.xml">
 <!ENTITY streamon SYSTEM "v4l/vidioc-streamon.xml">
+<!ENTITY dqevent SYSTEM "v4l/vidioc-dqevent.xml">
+<!ENTITY subscribe_event SYSTEM "v4l/vidioc-subscribe-event.xml">

Documentation/DocBook/v4l/dev-event.xml new file +31 -0

new file mode 100644
index 0000000..be5a98f
@@ -0,0 +1,31 @@
+  <title>Event Interface</title>
+
+  <para>The V4L2 event interface provides means for user to get
+  immediately notified on certain conditions taking place on a device.
+  This might include start of frame or loss of signal events, for
+  example.
+  </para>
+
+  <para>To receive events, the events the user is interested in first must
+  be subscribed using the &VIDIOC-SUBSCRIBE-EVENT; ioctl. Once an event is
+  subscribed, the events of subscribed types are dequeueable using the
+  &VIDIOC-DQEVENT; ioctl. Events may be unsubscribed using
+  VIDIOC_UNSUBSCRIBE_EVENT ioctl. The special event type V4L2_EVENT_ALL may
+  be used to unsubscribe all the events the driver supports.</para>
+
+  <para>The event subscriptions and event queues are specific to file
+  handles. Subscribing an event on one file handle does not affect
+  other file handles.
+  </para>
+
+  <para>The information on dequeueable events is obtained by using select or
+  poll system calls on video devices. The V4L2 events use POLLPRI events on
+  poll system call and exceptions on select system call.  </para>
+
+  <!--
+Local Variables:
+mode: sgml
+sgml-parent-document: "v4l2.sgml"
+indent-tabs-mode: nil
+End:
+  -->

Documentation/DocBook/v4l/v4l2.xml +3 -0

index 060105a..9737243 100644
@@ -401,6 +401,7 @@ and discussions on the V4L mailing list.</revremark>
     <section id="ttx"> &sub-dev-teletext; </section>
     <section id="radio"> &sub-dev-radio; </section>
     <section id="rds"> &sub-dev-rds; </section>
+    <section id="event"> &sub-dev-event; </section>
   </chapter>
 
   <chapter id="driver">

@@ -426,6 +427,7 @@ and discussions on the V4L mailing list.</revremark>
     &sub-cropcap;
     &sub-dbg-g-chip-ident;
     &sub-dbg-g-register;
+    &sub-dqevent;
     &sub-encoder-cmd;
     &sub-enumaudio;
     &sub-enumaudioout;

@@ -467,6 +469,7 @@ and discussions on the V4L mailing list.</revremark>
     &sub-reqbufs;
     &sub-s-hw-freq-seek;
     &sub-streamon;
+    &sub-subscribe-event;
     <!-- End of ioctls. -->
     &sub-mmap;
     &sub-munmap;

Documentation/DocBook/v4l/vidioc-dqevent.xml new file +124 -0

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Documentation/DocBook/v4l/vidioc-subscribe-event.xml new file +104 -0

104 lines not on this page · raw message

Documentation/video4linux/v4l2-framework.txt +60 -0

63 lines not on this page · raw message

Signature · 1 line

1.5.6.5

Sakari Ailus

2010-02-26 16:02 UTC #9 lore raw

V4L2 file handle and event patches

In reply to Sakari Ailus

Quoted 9 lines · Sakari Ailus

Hi,
Here's the tenth version of the V4L2 file handle and event interface patchset.
The patchset has been tested with the OMAP 3 ISP driver. Patches for OMAP 3 ISP are not part of this patchset but are available in Gitorious (branch is called event):

Quoted 5 lines

git://gitorious.org/omap3camera/mainline.git event
The patchset I'm posting now is against the v4l-dvb tree instead of linux-omap. The omap3camera tree thus has a slightly different version of these patches (just Makefiles) due to different baselines.

Hi Mauro,

What is your opinion on the file handle and event patchset? Could we get them integrated for 2.6.34? Hans Verkuil as well as many others have no more comments on them.

The patchset in question is v8.

Sincerely,

Signature · 2 lines

Sakari Ailus
[email protected]

Mauro Carvalho Chehab

2010-03-09 15:45 UTC #10 lore raw

In reply to Sakari Ailus

Sakari,

As usual, I'm marking those patches as RFC. Please add them on some tree and ask me to pull from it, when you think that event interface is ready for upstream merge.

Cheers,
Mauro.

Quoted 22 lines · Sakari Ailus

Hi,
Here's the tenth version of the V4L2 file handle and event interface patchset.
The patchset has been tested with the OMAP 3 ISP driver. Patches for OMAP 3 ISP are not part of this patchset but are available in Gitorious (branch is called event):
git://gitorious.org/omap3camera/mainline.git event
The patchset I'm posting now is against the v4l-dvb tree instead of linux-omap. The omap3camera tree thus has a slightly different version of these patches (just Makefiles) due to different baselines.
Some more comments from Hans and Randy. There are only improvements in documentation this time.
Comments are welcome as always.
Cheers,

Signature · 2 lines

Cheers,
Mauro