Re: [PATCH/RFC 4/5] regulator: bd9571mwv: Add support for backup mode

From: Mark Brown
Date: Tue Oct 24 2017 - 04:34:54 EST


On Wed, Oct 18, 2017 at 01:28:30PM +0200, Geert Uytterhoeven wrote:
> On Wed, Oct 18, 2017 at 1:24 PM, Mark Brown <broonie@xxxxxxxxxx> wrote:

> >> Hence you cannot enable wakeup mode while suspending, as the proper
> >> system suspend/resume procedure is:
> >> 1. Enable backup mode in the PMIC,
> >> 2. Switch ACC off (no-op as backup mode has been enabled),
> >> 3. Suspend to RAM (PSCI suspend) => system suspends,
> >> 4. Switch ACC on => system wakes up.
> >> If you would combine steps 1 and 3, you can no longer do step 2 in between.

> >> Yes, it's complicated :-(

> > I'm confused, I thought this was a physical switch but that's talking
> > about this as something software controlled (at least in step 2)?

> The ACC switch is a physical switch.
> Steps 1 and 3 are performed by software running on the board's SoC.
> Steps 2 and 4 are performed by the external user (human or remote board
> farm control hookup).

That's horrible. There's still the question about potentially using the
existing wakeup file to manage if the device is a wakeup source but
otherwise I guess the only other thing that'd make sense would be just
having a property in the DT.

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