[U-Boot] [PATCH 2/3] ARM: Tegra: USB: Add driver support for Tegra30/Tegra114

[Tom Warren]

Tom,


On Tue, Apr 30, 2013 at 10:20 AM, Tom Rini <trini at ti.com> wrote:

> On Tue, Apr 30, 2013 at 09:21:18AM -0700, Tom Warren wrote:
>
> > Marek,
> >
> > > -----Original Message-----
> > > From: Marek Vasut [mailto:marex at denx.de]
> > > Sent: Monday, April 29, 2013 4:47 PM
> > > To: Jim Lin
> > > Cc: u-boot at lists.denx.de; Tom Warren; Stephen Warren
> > > Subject: Re: [PATCH 2/3] ARM: Tegra: USB: Add driver support for
> > > Tegra30/Tegra114
> > >
> > > Dear Jim Lin,
> > >
> > > > Tegra30 and Tegra114 are compatible except 1. T30 takes 55 ms to
> > > > finish Port Reset. T114 takes
> > > >    50 ms.
> > > > 2. PLL parameters
> > > >
> > > > Tested on Tegra20 Harmony/Seaboard, Tegra30 Cardhu, and Tegra114
> > > > Dalmore platforms. All works well.
> > > >
> > > > Signed-off-by: Jim Lin <jilin at nvidia.com>
> > > > ---
> > > >  arch/arm/include/asm/arch-tegra/clk_rst.h  |   10 +
> > > >  arch/arm/include/asm/arch-tegra/usb.h      |  249 ------------------
> > > >  arch/arm/include/asm/arch-tegra114/tegra.h |    1 +
> > > >  arch/arm/include/asm/arch-tegra114/usb.h   |  287
> > > +++++++++++++++++++++
> > > >  arch/arm/include/asm/arch-tegra20/usb.h    |  279
> > > +++++++++++++++++++++
> > > >  arch/arm/include/asm/arch-tegra30/usb.h    |  294
> > > ++++++++++++++++++++++
> > >
> > > Do we now have three copies of the same stuff ?
> >
> > When only T20 was supported (for USB), there was a common
> > (arch-tegra/usb.h) header. That's been moved to arch-tegra20/usb.h,
> > and (unfortunately) there are 2 new usb.h files due to the HW
> > differences in the registers between T20 and T30/T114.  I don't see
> > any easy way to have a common usb.h file for Tegra w/o adding ugly
> > #ifdefs to the USB register space struct(s).
>
> Just how different are they?  Are all of the related defines and masks
> different too?  Do we have conflicts? Moved registers?  Just conflicting
> values?  A quick peek shows '30' and '114' are pretty similar, except
> for masks.  Maybe splitting the struct up so you can discard some of the
> reserved gaps, run-time checking to see if we can or cannot use a
> particular part of the struct?
>

This is really Jim's patchset (and his specialty), but here's what I know
about Tegra USB regs:

T20 had a gap in the registers @ offset 0x130. T30 (and T114) moved the
offset of the command/status/interrupt regs down to fill in this gap, which
dragged all the subsequent registers back 16 bytes. The two SoCs 'families'
sync up again at offset 0x400 and are pretty much equal from there on out
to 0x840.

The defines are probably 90% the same, with some weirdness for the first
USB controller (USB1) and its PTS/STS bits that differs in offset from the
other 2 controllers (again, no clue why the HW guys would do this).

So we could have the 3 different USB headers in the arch-tegraXX area
contain the register structs, and have a common arch-tegra/usb.h that has
the #defines that are the same, and is included in the arch-tegraxx/usb.h
files. That would reduce this down somewhat, without the ugliness of
#ifdefs in the structs.

What do you think?

Tom

>
> --
> Tom
>