[U-Boot] [PATCH 23/23] ARM: tegra: Enable PCIe on Jetson TK1

Thierry Reding
2014-08-22T19:40:31Z

On Fri, Aug 22, 2014 at 01:27:57PM -0600, Simon Glass wrote:
> On 22 August 2014 06:09, Thierry Reding <thierry.reding@gmail.com> wrote:
[...]
> > Note that I haven't turned the AS3722 support into a "PMIC" driver,
> > because the framework for that seems to be unusable. It doesn't seem to
> > abstract away driver-specifics at all but rather provides a way to
> > access registers in a uniform way (sort of what regmap does in Linux).
> > Using that framework would therefore require knowledge about the exact
> > register accesses within drivers and therefore wouldn't be an
> > improvement over the current situation.
> >
>
> It doesn't provide a PMIC API as such - just a way to find a PMIC and the
> access registers. I think it is useful for that at least.

But that's not very useful in itself, is it? I mean, there's no
abstraction whatsoever for the PMIC functionality, so all users will
need to implement direct register accesses, which essentially means
there's about zero code reuse. So the abstraction is at the wrong point
in my opinion and the only use-case where I think it would be beneficial
is if the same PMIC could be used on different interfaces (I2C vs. SPI)
and therefore the register access abstraction could allow a single
driver to control both types.

I've opted instead to provide an somewhat higher-level API that users
can call to set voltages on the regulators and enable them.

Thierry
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