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authorLinus Torvalds <torvalds@linux-foundation.org>2013-02-24 20:35:10 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-24 20:35:10 -0500
commit21fbd5809ad126b949206d78e0a0e07ec872ea11 (patch)
treea824045df99fc1f0690095a925cceb50207e332b /Documentation/video4linux/v4l2-controls.txt
parentd9978ec5680059d727b39d6c706777c6973587f2 (diff)
parented72d37a33fdf43dc47787fe220532cdec9da528 (diff)
Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab: - Some cleanups at V4L2 documentation - new drivers: ts2020 frontend, ov9650 sensor, s5c73m3 sensor, sh-mobile veu mem2mem driver, radio-ma901, davinci_vpfe staging driver - Lots of missing MAINTAINERS entries added - several em28xx driver improvements, including its conversion to videobuf2 - several fixups on drivers to make them to better comply with the API - DVB core: add support for DVBv5 stats, allowing the implementation of statistics for new standards like ISDB - mb86a20s: add statistics to the driver - lots of new board additions, cleanups, and driver improvements. * 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (596 commits) [media] media: Add 0x3009 USB PID to ttusb2 driver (fixed diff) [media] rtl28xxu: Add USB IDs for Compro VideoMate U620F [media] em28xx: add usb id for terratec h5 rev. 3 [media] media: rc: gpio-ir-recv: add support for device tree parsing [media] mceusb: move check earlier to make smatch happy [media] radio-si470x doc: add info about v4l2-ctl and sox+alsa [media] staging: media: Remove unnecessary OOM messages [media] sh_vou: Use vou_dev instead of vou_file wherever possible [media] sh_vou: Use video_drvdata() [media] drivers/media/platform/soc_camera/pxa_camera.c: use devm_ functions [media] mt9t112: mt9t111 format set up differs from mt9t112 [media] sh-mobile-ceu-camera: fix SHARPNESS control default Revert "[media] fc0011: Return early, if the frequency is already tuned" [media] cx18/ivtv: fix regression: remove __init from a non-init function [media] em28xx: fix analog streaming with USB bulk transfers [media] stv0900: remove unnecessary null pointer check [media] fc0011: Return early, if the frequency is already tuned [media] fc0011: Add some sanity checks and cleanups [media] fc0011: Fix xin value clamping Revert "[media] [PATH,1/2] mxl5007 move reset to attach" ...
Diffstat (limited to 'Documentation/video4linux/v4l2-controls.txt')
-rw-r--r--Documentation/video4linux/v4l2-controls.txt22
1 files changed, 14 insertions, 8 deletions
diff --git a/Documentation/video4linux/v4l2-controls.txt b/Documentation/video4linux/v4l2-controls.txt
index cfe52c798d74..676f87366025 100644
--- a/Documentation/video4linux/v4l2-controls.txt
+++ b/Documentation/video4linux/v4l2-controls.txt
@@ -715,14 +715,20 @@ a control of this type whenever the first control belonging to a new control
715class is added. 715class is added.
716 716
717 717
718Proposals for Extensions 718Adding Notify Callbacks
719======================== 719=======================
720
721Sometimes the platform or bridge driver needs to be notified when a control
722from a sub-device driver changes. You can set a notify callback by calling
723this function:
720 724
721Some ideas for future extensions to the spec: 725void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl,
726 void (*notify)(struct v4l2_ctrl *ctrl, void *priv), void *priv);
722 727
7231) Add a V4L2_CTRL_FLAG_HEX to have values shown as hexadecimal instead of 728Whenever the give control changes value the notify callback will be called
724decimal. Useful for e.g. video_mute_yuv. 729with a pointer to the control and the priv pointer that was passed with
730v4l2_ctrl_notify. Note that the control's handler lock is held when the
731notify function is called.
725 732
7262) It is possible to mark in the controls array which controls have been 733There can be only one notify function per control handler. Any attempt
727successfully written and which failed by for example adding a bit to the 734to set another notify function will cause a WARN_ON.
728control ID. Not sure if it is worth the effort, though.