The DRIVEVBUS power rail of the AXP803 PMIC is mostly used to supply
the USB bus power on micro USB sockets, when used in host mode. As this
is a dynamic operation, and mostly we want micro USB sockets to act in
client mode initially, BL31 should not actually enable this power line.
However, on some boards DRIVEVBUS is used to supply power to normal
USB-A sockets. Failing to activate this line there results in
non-functional USB in U-Boot on those boards.

For that reason we were enabling DRIVEVBUS so far, as it did not seem to
cause any harm to the other boards. However it turns out that on the
Pinephone (and other systems with a battery), actually enabling DRIVEVBUS
unconditionally causes serious problems (reboot loop).

To accommodate both use cases, without reverting to a build time option,
check the default OTG configuration in the devicetree. For boards with
USB-A sockets this is set to "host", on boards with micro-B sockets to
"otg". Depending on this setting, we either enable DRIVEVBUS or leave it
alone.

This fixes TF-A on the Pinephone and potentially other battery powered
devices.

Change-Id: Iec0e07f218b2b4393bf4e05c3386261f8ed19e9f
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

This adds the new regulator list, as well as changes to make the switch
(equivalent to DC1SW on the AXP803) work on both PMICs.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: I9a1eac8ddfc54b27096c10a8eebdd51aaf9b8311

Previously, the A64/H5 and H6 platforms' PMIC setup code was entirely
independent. However, some H6 boards also need early regulator setup.

Most of the register interface and all of the device tree traversal code
can be reused between the AXP803 and AXP805. The main difference is the
hardware bus interface, so that part is left to the platforms. The
remainder is moved into a driver.

I factored out the bits that were obviously specific to the AXP803;
additional changes for compatibility with other PMICs can be made as
needed.

The only functional change is that rsb_init() now checks the PMIC's chip
ID register against the expected value. This was already being done in
the H6 version of the code.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: Icdcf9edd6565f78cccc503922405129ac27e08a2