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

On Wed, Oct 18, 2017 at 01:28:30PM +0200, Geert Uytterhoeven wrote:

On Wed, Oct 18, 2017 at 1:24 PM, Mark Brown [off-list ref] wrote:

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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.

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Yes, it's complicated :-(

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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.