[U-Boot] [PATCH v2 00/40] ARM: tegra: Add PCIe support

[Simon Glass]

Hi Thierry,

On 29 September 2014 02:11, Thierry Reding <thierry.reding at gmail.com> wrote:

> On Sun, Sep 28, 2014 at 04:48:47PM -0600, Simon Glass wrote:
> > Hi Thierry,
> >
> > On 26 August 2014 09:33, Thierry Reding <thierry.reding at gmail.com>
> wrote:
> >
> > > From: Thierry Reding <treding at nvidia.com>
> > >
> > > This series adds PCIe support for Tegra20, Tegra30 and Tegra124. The
> size
> > > is
> > > mostly due to the large number of infrastructure that's added (libfdt,
> > > Tegra
> > > specific drivers required by the PCIe driver). In this version I've
> > > included
> > > all patches that were previously split into three separate series.
> > > Spreading
> > > them over multiple series is probably not worth it since there might be
> > > some
> > > dependencies between them and only the end result gives a completely
> > > working
> > > setup.
> > >
> >
> > FYI I have applied this series on top of driver model - it is at
> > u-boot-dm.git branch 'norrin-working'. There were a quite few conflicts
> > which I resolved (mostly with mainline I think). I tested it on beaver,
> > trimslice and jetson-tk1.
> >
> > Are you going to respin it?
>
> I started looking at DM for I2C as Heiko suggested but it became too
> complex and time consuming, so what I'm planning to do is drop the I2C
> "enhancements" and use plain i2c_set_bus_num() and friends.
>

OK. I looked at the series and you should really be using the pmic
framework. I've pushed a branch to 'dm/norrin-working' that changes it (see
the as3722 patch near the top). See tps65090 for an example. It should
avoid any messing with I2C. Then, when the new PMIC framework rolls out
your code will ride along for free. Plus you can drop the i2c additions
that way.

Also, there is a clock function that seems to bash various registers -
tegra_plle_enable. I think this should use clock_set_rate() - i.e. build in
support for the new clock rather than creating a parallel function.

The power gate stuff looks good. Are you planning to replace the power gate
code in arch/arm/cpu/arm720t/tegra124/cpu.c and the like? The only minor
issue I see is the availability of get_timer() - but in
tegra_powergate_set() 25ms seems like a very long delay to me anyway.


> If there's any interest I can push a branch with the work-in-progress
> I2C DM patches, perhaps it could serve as the basis if someone else
> wanted to continue with that effort.
>

Yes I think that would be useful.

Regards,
Simon