[U-Boot] [RFC PATCH 0/3] i.MX6 (DQ/DLS): consolidate mux and pad names

[Eric Nelson <eric.nelson@boundarydevices.com>]

Thanks Tapani,

On 09/24/2013 02:36 AM, Tapani Utriainen wrote:
> On Fri, 20 Sep 2013 17:22:58 -0700
> Eric Nelson <eric.nelson@boundarydevices.com> wrote:
>
>> On 09/16/2013 02:26 PM, Eric Nelson wrote:
>>> This patch set begins the process of consolidating mux and pad
>>> declarations for the i.MX6 Dual/Quad and Dual-Lite/Solo processor
>>> variants.
>>>
>>> Patch 1 replaces the mux/pad names with their equivalents from
>>> 	the Linux kernel (from linux-next). This
>>> Patch 2 removes a set of completely useless pad declarations
>>> Patch 3 adds a number of registers that are defined in the Linux
>>> 	kernel and in the DLS variant, but not in the DQ.
>>>
>>> After this patch, there are still more than 400 pad differences
>>> between the two variants. These represent mux/pad declarations
>>> that are not present in the Linux kernel. A combined list of these
>>> is available at:
>>> 	http://linode.boundarydevices.com/u-boot-pads.lst
>>>
>>> The majority of these are diagnostic settings and a large number
>>> of these appear unlikely to ever be used. The primary reason this
>>> is being sent as an RFC is to get feedback about what should be
>>> done with them:
>>> 	1. Delete them all
>>> 	2. Walk through them and delete some and add others
>>> 	3. Add them all and consolidate the names.
>>>
>>
>> Shawn and Fabio: I'd like to find out what you think about
>> how to handle the pads that aren't in the kernel tree.
>>
>> Please advise,
>>
>
> Just adding two (more) cents:
>
> At least padconfig definitions like
>
> DRAM_A0__MMDC_DRAM_A_0,
> DRAM_A1__MMDC_DRAM_A_1,
> DRAM_A2__MMDC_DRAM_A_2,
> DRAM_A3__MMDC_DRAM_A_3,
> DRAM_A4__MMDC_DRAM_A_4,
> DRAM_A5__MMDC_DRAM_A_5,
> DRAM_A6__MMDC_DRAM_A_6,
> DRAM_A7__MMDC_DRAM_A_7,
> DRAM_A8__MMDC_DRAM_A_8,
> DRAM_A9__MMDC_DRAM_A_9
>
> etc. might be useful as soon as memory is set up programmatically
> rather than using DCD tables.
>
Some of these pads are already defined in mx6q-ddr.h/mx6dl-ddr.h:

	http://git.denx.de/u-boot.git/?p=u-boot.git;a=blob;f=arch/arm/include/asm/arch-mx6/mx6q-ddr.h;h=0aa94cffe5177bf89fbfa59cd2bc423285a96d64;hb=HEAD

Oddly, the ones you refer to aren't.

> Hence, my suggestion is not to delete them all. At least leave the
> MMDC padconfigs in.
>

Do you think these registers will be easier to work with
via the IOMUX_PAD macro or as straight macros?

If they're straight-up #defines, we can use them in assembly
and .cfg files.

Please advise,


Eric