Re: [RFC PATCH v2 0/6] ARM: OMAP3+: Introduce ABB driver

[Kevin Hilman <khilman@linaro.org>]

Andrii Tseglytskyi <andrii.tseglytskyi@ti.com> writes:

> From: "Andrii.Tseglytskyi" <andrii.tseglytskyi@ti.com>
>
> Following patch series introduces the Adaptive Body-Bias
> LDO driver, which handles LDOs voltage during OPP change routine.
> Current implementation is based on patch series from
> Mike Turquette:
>
> http://marc.info/?l=linux-omap&m=134931341818379&w=2
>
> ABB transition is a part of OPP changing sequence.
> ABB can operate in the following modes:
> - Bypass mode: Activated when ABB is not required
> - FBB mode: Fast Body Bias mode, used on fast OPPs

Fast?  I thought the 'F' was for Forward?

> - RBB mode: Reverse Body Bias mode, used on slow OPPs
>
> In current implementation ABB is converted to regulator.
> Standalone OPP table is used to store ABB mode, it is defined
> in device tree for each ABB regulator. It has the following format:
>
> operating-points = <
> 	       /* uV   ABB (0 - Bypass, 1 - FBB, 2 - RBB) */
> 	       880000		0
> 	       1060000		1
> 	       1250000		1
> 	       1260000		1
>>;
>
> ABB regulator is linked to regulator chain

In addition to Mike's comments (which I completely agree with), it would
be very helfpul to see how this is actually used.  e.g, how the
regulators are chained together, how the proper ordering is managed,
etc. etc.

IOW, This series gives a bunch of low-level details without
demonstrating the actual use case and showing the regulator API usage
that would make this work.

Kevin