[U-Boot] [PATCH v2 0/6] rk3399-puma: Enable PWM regulator for RK3399-Q7

[Philipp Tomsich]

Christoph,

> On 12.12.2018, at 01:57, Christoph Muellner <christoph.muellner at theobroma-systems.com> wrote:
> 
> This patch series allows to tune VDD_LOG on RK3399-Q7 Puma boards
> to a voltage level defined in the DTS using a PWM adjustable regulator.
> 
> To do so a reimplemenation of the RK3399 pinctrl driver has been done.
> Although the new pinctrl driver is written in a way, that we could
> merge it with other rockchip pinctrl drivers, this is has not been done
> as part of this series.

As discussed today, when I came by your desk: thanks for taking this
on; it had been on my wish-list for a long time.

Given the fact that this may have unintended side-effects for some of
the other RK3399 boards, I am considering to hold this back until the
next merge window (even though I know that we’d like to change the
vdd_log setting as soon as possible to properly support the one use-case
that triggered this entire effort).

> The effect of the series is, that VDD_LOG will be set to about 950 mV
> on Puma. This is required to address stability issues on Puma.
> As a side effect, the pinctrl settings of all RK3399 boards will
> be configured according to the description in the DTS.

I wonder if we should add a transitional Kconfig entry to enable this only
for boards that opt-in for the current release… this would allow us to pull
this in for 2019.1 and then make it an unconditional feature starting early
in the next merge-window.

Philipp.