From: masneyb@onstation.org (Brian Masney)
To: kernelnewbies@lists.kernelnewbies.org
Subject: How to control power of a device from sysfs ?
Date: Mon, 5 Dec 2016 05:29:14 -0500 [thread overview]
Message-ID: <20161205102914.GA23211@basecamp.onstation.org> (raw)
In-Reply-To: <CAJ2oMh+HuJhWHGqATxi27W_=kj2R=8XOw0NLW0tc6HY4HJZPqg@mail.gmail.com>
On Mon, Dec 05, 2016 at 09:26:27AM +0200, Ran Shalit wrote:
> Hello,
>
> I am trying to turn off screen using sysfs entries,
> but I'm having some difficulties with it:
>
> 1.
> command:
> echo 0 > /sys/devices/platform/s5p-dsim.0/ea8061/backlight/panel/brightness
> result:
> screen is dimmed - BUT not turned off
>
> 2.
> command:
> cat
> /sys/devices/platform/s5p-dsim.0/ea8061/backlight/panel/actual_brightness
> 20
>
> This strengthen the fast that we didn't turned off brightness completely
>
> 3. In this point I though that maybe I can turn off the whole brightness
> device
>
> ls /sys/devices/platform/s5p-dsim.0/ea8061/backlight/panel/
> actual_brightness
> auto_brightness
> bl_power
> brightness
> device
> dimming
> max_brightness
> power
> subsystem
> type
> uevent
>
> I made some trials , but didn't made it turned off yet.
> Is there any idea if it's possible to turn it off completely ?
If the driver supports power management, then you can control the power
state with the power/runtime_status sysfs entry. Some of the sysfs
entries in the power/ directory are documented in
Documentation/ABI/testing/sysfs-devices-power.
Brian
prev parent reply other threads:[~2016-12-05 10:29 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-05 7:26 How to control power of a device from sysfs ? Ran Shalit
2016-12-05 8:24 ` Umair Khan
2016-12-05 8:48 ` Ran Shalit
2016-12-05 10:29 ` Brian Masney [this message]
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