On Sun, May 8, 2016 at 3:28 PM, Timur Tabi <[email protected]> wrote: > On Mon, May 2, 2016 at 6:43 AM, Mario Six <[email protected]> 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. >
The problem is that in 36-bit mode the physical addresses are 64-bit, which means that you get 64-bit integers when you read something from the device tree with fdtdec_get_addr. But the device tree addresses themselves seem to be 32-bit, because if I read a property like 'reg = <0xf000 0x100>', I get a 64-bit value that contains two 32-bit values, so I have to do 'addr = reg >> 32; size = reg & 0xFFFFFFFF;' to extract them (see the patch). Doing that poses a problem if you use the 32-bit mode, though, since then the physical addresses are 32-bit. After reading your comment (and a bit of digging), I found the fdtdec_get_addr_size_auto_noparent function, which seems to fix that problem (by taking the parent's address-size values into account). I'll respin the patches with that function and Simon's concerns addressed. Thanks for the help! Best regards, Mario _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
