docs(allwinner): add SUNXI_SETUP_REGULATORS build option

Document the newly introduced SUNXI_SETUP_REGULATORS build option, that
allows to disable PMIC regulator setup at build time.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Change-Id: Ie5fb0b7220426b67cfffc95df4cabb31a6ec174a
This commit is contained in:
Andre Przywara 2021-12-27 15:09:53 +00:00
parent 67412e4d7a
commit aa61699027
1 changed files with 16 additions and 0 deletions

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@ -26,6 +26,22 @@ To build for machines with an H616 or H313 SoC:
make CROSS_COMPILE=aarch64-linux-gnu- PLAT=sun50i_h616 DEBUG=1 bl31
Platform-specific build options
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The default build options should generate a working firmware image. There are
some build options that allow to fine-tune the firmware, or to disable support
for optional features.
- ``SUNXI_SETUP_REGULATORS`` : On SoCs that typically ship with a PMIC
power management controller, BL31 tries to set up all needed power rails,
programming them to their respective voltages. That allows bootloader
software like U-Boot to ignore power control via the PMIC.
This setting defaults to 1. In some situations that enables too many
regulators, or some regulators need to be enabled in a very specific
sequence. To avoid problems with those boards, ``SUNXI_SETUP_REGULATORS``
can bet set to ``0`` on the build command line, to skip the PMIC setup
entirely. Any bootloader or OS would need to setup the PMIC on its own then.
Installation
------------