[PATCH v2 2/2] ARM: mxs: Pass the system revision
From: festevam@gmail.com (Fabio Estevam)
Date: 2013-06-01 14:58:18
Hi Michael, On Sat, Jun 1, 2013 at 9:19 AM, Michael Heimpold [off-list ref] wrote:
I think it would be difficult to use system_rev for this purpose as some boards I know about are using this field to pass a board/PCB revision from U-Boot to the kernel.
Can you please provide some real examples? For mx28 I see no boards passing ATAGS from bootloader to the kernel. If you look at FSL kernel code the system revision is hardcoded in the board file. For mx5/mx6 boards we do pass ATAGS from bootloader to kernel in the same format it was used here. For example: on mx53 it will be 0x53112 (where 0x53 means mx53, 1 is the board revision and 12 means TO1.2)
After spending a short look through documentation in kernel and U-Boot I did not find any hint whether this was the indended usage of this field. I would rather argue about introducing a new line "SoC revision: ..." as this is the revision you want to pass to user-space. The lines "Revision" and "Serial" should IMHO left alone for usage by board vendors.
As I mentioned in the commit log, the only reason we are doing this here is to allow a mainline kernel to run som mxs applications like Gstreamer plugins and kobs-ng. Regards, Fabio Estevam