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ACPI doesn’t have any bindings available for the regulator specifically and the regulator enable/disable etc. are typically handled by the ACPI device power methods.Looking at a diverse set of devices like low-speed/high-speed IO, sound cards, video, backlight, etc. for multiple Arm platforms, there doesn’t seem to any need for voltage regulator binding beyond what is required for power saving which is already handled by the device power methods
Example - SDHCI (SD/MMC/eMMC)
SD card interface requires 1.8V or 3.3V signaling depending on the usage mode as shown below.
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I.MX8MP Platform
I.MX8MP platform provides a control bit (VSELECT) on a memory-mapped register VEND_SPEC to select the required voltage.
The value of the output signal VSELECT from the controller can be configured by changing the value in the register and there must be a control circuit out of SDHC controller to change the voltage on pads.