[RFC][PATCH v3 1/3] runtime interpreted power sequences

Greg Kroah-Hartman gregkh at linuxfoundation.org
Sat Jul 28 04:19:23 EST 2012


On Fri, Jul 27, 2012 at 09:05:48PM +0900, Alexandre Courbot wrote:
> Some device drivers (panel backlights especially) need to follow precise
> sequences for powering on and off, involving gpios, regulators, PWMs
> with a precise powering order and delays to respect between each steps.
> These sequences are board-specific, and do not belong to a particular
> driver - therefore they have been performed by board-specific hook
> functions to far.
> 
> With the advent of the device tree and of ARM kernels that are not
> board-tied, we cannot rely on these board-specific hooks anymore but
> need a way to implement these sequences in a portable manner. This patch
> introduces a simple interpreter that can execute such power sequences
> encoded either as platform data or within the device tree.
> 
> Signed-off-by: Alexandre Courbot <acourbot at nvidia.com>
> ---
>  Documentation/power/power_seq.txt | 120 +++++++++++++++
>  drivers/base/Kconfig              |   4 +
>  drivers/base/Makefile             |   1 +
>  drivers/base/power_seq.c          | 300 ++++++++++++++++++++++++++++++++++++++
>  include/linux/power_seq.h         | 139 ++++++++++++++++++

What's wrong with drivers/power/?  I sure don't want to maintain this
code, and it seems to not be part of the "driver core" infrastructure.

thanks,

greg k-h


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