On Tue, Feb 02, 2021 at 02:29:54PM +0100, Mauro Carvalho Chehab wrote: > On Hikey 970, there's a power supply controlled by Hi6421v600 > regulator that turns on the PCI devices on the board. Without > that, no PCI hardware would work. > > As this is device-dependent, such regulator line should be > optional. Supplies should only be optional if they may be physically absent from the system, if they are just sometimes not described well in firmware they should be requested via the normal regulator_get() interface, the core will supply a dummy regulator if there is nothing at all in the firmware description. Supplies should also generally be referred to with the naming used in the datasheet for the part.