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author | Hans Verkuil <hverkuil@xs4all.nl> | 2018-02-21 08:49:25 +0100 |
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committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2018-03-21 17:05:39 +0100 |
commit | 3aab15af9ad8fa8dc0399cb4b679d7cb85c20a56 (patch) | |
tree | acd07cf67ae4ab9c752774d71a55489974359974 /include | |
parent | media: vb2-core: vb2_ops: document non-interrupt-context calling (diff) | |
download | linux-3aab15af9ad8fa8dc0399cb4b679d7cb85c20a56.tar.xz linux-3aab15af9ad8fa8dc0399cb4b679d7cb85c20a56.zip |
media: add tuner standby op, use where needed
The v4l2_subdev core s_power op was used for two different things: power on/off
sensors or video decoders/encoders and to put a tuner in standby (and only the
tuner!). There is no 'tuner wakeup' op, that's done automatically when the tuner
is accessed.
The danger with calling (s_power, 0) to put a tuner into standby is that it is
usually broadcast for all subdevs. So a video receiver subdev that supports
s_power will also be powered off, and since there is no corresponding (s_power, 1)
they will never be powered on again.
In addition, this is specifically meant for tuners only since they draw the most
current.
This patch adds a new tuner op called 'standby' and replaces all calls to
(core, s_power, 0) by (tuner, standby). This prevents confusion between the two
uses of s_power. Note that there is no overlap: bridge drivers either just want
to put the tuner into standby, or they deal with powering on/off sensors. Never
both.
This also makes it easier to replace s_power for the remaining bridge drivers
with some PM code later.
Whether we want something cleaner for tuners in the future is a separate topic.
There is a lot of legacy code surrounding tuners, and I am very hesitant about
making changes there.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'include')
-rw-r--r-- | include/media/v4l2-subdev.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h index 2561222322d5..9102d6ca566e 100644 --- a/include/media/v4l2-subdev.h +++ b/include/media/v4l2-subdev.h @@ -224,6 +224,9 @@ struct v4l2_subdev_core_ops { * struct v4l2_subdev_tuner_ops - Callbacks used when v4l device was opened * in radio mode. * + * @standby: puts the tuner in standby mode. It will be woken up + * automatically the next time it is used. + * * @s_radio: callback that switches the tuner to radio mode. * drivers should explicitly call it when a tuner ops should * operate on radio mode, before being able to handle it. @@ -268,6 +271,7 @@ struct v4l2_subdev_core_ops { * } */ struct v4l2_subdev_tuner_ops { + int (*standby)(struct v4l2_subdev *sd); int (*s_radio)(struct v4l2_subdev *sd); int (*s_frequency)(struct v4l2_subdev *sd, const struct v4l2_frequency *freq); int (*g_frequency)(struct v4l2_subdev *sd, struct v4l2_frequency *freq); |