Re: [PATCH v3 1/5] dt-bindings: mfd: rk806: allow to customize PMIC reset mode
From: Krzysztof Kozlowski
Date: Thu Jun 19 2025 - 05:54:37 EST
On Wed, Jun 18, 2025 at 12:32:40PM GMT, Quentin Schulz wrote:
> From: Quentin Schulz <quentin.schulz@xxxxxxxxx>
>
> The RK806 PMIC allows to configure its reset/restart behavior whenever
> the PMIC is reset either programmatically or via some external pins
> (e.g. PWRCTRL or RESETB).
>
> The following modes exist:
> - 0; restart PMU,
> - 1; reset all power off reset registers and force state to switch to
> ACTIVE mode,
> - 2; same as mode 1 and also pull RESETB pin down for 5ms,
>
> For example, some hardware may require a full restart (mode 0) in order
> to function properly as regulators are shortly interrupted in this mode.
>
> This is the case for RK3588 Jaguar and RK3588 Tiger which have a
> companion microcontroller running on an independent power supply and
> monitoring the PMIC power rail to know the state of the main system.
> When it detects a restart, it resets its own IPs exposed to the main
> system as if to simulate its own reset. Failing to perform this fake
> reset of the microcontroller may break things (e.g. watchdog not
> automatically disabled, buzzer still running until manually disabled,
> leftover configuration from previous main system state, etc...).
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Best regards,
Krzysztof