Re: [PATCH v5 6/7] pmdomain: rockchip: add regulator support

[Heiko Stübner]

Am Mittwoch, 11. Dezember 2024, 15:26:51 CET schrieb Sebastian Reichel:
> Some power domains require extra voltages to be applied. For example
> trying to enable the GPU power domain on RK3588 fails when the SoC
> does not have VDD GPU enabled. The same is expected to happen for
> the NPU, which also has a dedicated supply line.
> 
> We get the regulator using devm_of_regulator_get(), so a missing
> dependency in the devicetree is handled gracefully by printing a warning
> and creating a dummy regulator. This is necessary, since existing DTs do
> not have the regulator described. They might still work if the regulator
> is marked as always-on. It is also working if the regulator is enabled
> at boot time and the GPU driver is probed before the kernel disables
> unused regulators.
> 
> The regulator itself is not acquired at driver probe time, since that
> creates an unsolvable circular dependency. The power domain driver must
> be probed early, since SoC peripherals need it. Regulators on the other
> hand depend on SoC peripherals like SPI, I2C or GPIO. MediaTek does not
> run into this, since they have two power domain drivers.
> 
> Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>
> Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>

Reviewed-by: Heiko Stuebner <heiko@xxxxxxxxx>