Re: [PATCH v6 1/4] Runtime Interpreted Power Sequences

From: Alex Courbot
Date: Thu Sep 13 2012 - 02:06:30 EST


On Thursday 13 September 2012 13:45:39 Tomi Valkeinen wrote:
> * PGP Signed by an unknown key
>
> On Wed, 2012-09-12 at 18:57 +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.
>
>
> The sequences are not board-specific, they are device (backlight, etc.)
> specific. The sequences have been handled in board-specific hook
> functions so far because there hasn't been proper drivers for the
> devices.
>
> If I were to take the same panel (and backlight) you have and install it
> on my board, I would need the same power sequence.

You could also have power sequences that control a set of GPIOs for an
external interface (and would then be more board-specific), but you are right
that for most of the case power seqs apply to devices and this statement is
misleading. I will fix that in the commit message and wherever this might
appear.

Alex.

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