[U-Boot] [PATCH 1/3] dm: gpio: Add driver for MPC85XX GPIO controller

Timur Tabi timur at tabi.org
Sun May 8 15:28:25 CEST 2016


On Mon, May 2, 2016 at 6:43 AM, Mario Six <mario.six at gdsys.cc> wrote:
> Regarding the address width discrepancy: The system I'm working on is a
> P1022 Qoriq, which has 36 bit width, which implies that phys_addr_t needs
> to be 64 bit. But the everything else (including the GPIO controller) uses
> 32 bits, thus the device tree addresses are 32 bit wide. I'm not quite sure
> how to handle this difference; DM support for this platform is brand-new,
> so there are no drivers to look to for guidance.

I did primary development on the P1022DS, so maybe I can help.  It's
been a while since I've worked on it, though.

First, note that there are two versions of the P1022DS DTS: one is
32-bit, and the other is 36-bit.  This was back when Freescale's SOCs
were transitioning to 36-bit physical addresses.  So if you're never
going to have more than 2GB of RAM in your system, you can use 32-bit
physical addresses in the DTS.

Can you explain the problem again?  Like I said, it's been a while,
but I have a hard time believing that you've discovered a new problem
on the P1022 that hasn't already been solved.


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