[U-Boot] [PATCH v1 2/2] arm: mvebu: Define NAND interface pins for A-38x

[Chris Packham]

Hi Stefan,

On Tue, Aug 23, 2016 at 10:54 PM, Chris Packham <judge.packham at gmail.com> wrote:
> On Tue, Aug 23, 2016 at 6:57 PM, Stefan Roese <sr at denx.de> wrote:
>> Hi Chris,
>>
>> On 22.08.2016 02:38, Chris Packham wrote:
>>>
>>> From: Chris Packham <chris.packham at alliedtelesis.co.nz>
>>>
>>> Add pin control settings for the NAND flash interface. This interface
>>> is multiplexed with the device bus interface to the function is "dev"
>>> not "nand" as one might expect.
>>>
>>> Signed-off-by: Chris Packham <chris.packham at alliedtelesis.co.nz>
>>> Cc: Luka Perkov <luka.perkov at sartura.hr>
>>> Cc: Dirk Eibach <eibach at gdsys.de>
>>> ---
>>> I don't think this is strictly necessary. A quick scan of boards that
>>> use this family of processor all seem to set their MPP configurations
>>> manually.
>>
>>
>> Correct. Unfortunately we don't have a pin-ctrl driver for AXP / A38x
>> in U-Boot yet. Such a driver would be very welcome though. ;)
>>
>>> Another issue is that technically on the Armada-385 there are 4 possible
>>> CE pins. The board I'm looking at happens to use CE#0 (mpp25) but mpp26,
>>> mpp27 and mpp6 are all potentially available. I guess if any boards
>>> actually use them they can add them to their pin specification. At the
>>> very least such boards would need to update the num-cs property anyway.
>>
>>
>> How is this handled in the kernel?
>
> I haven't seen anything in the kernel yet that uses these chip selects.
>
>> I would very much like to see
>> these changes in the dts in sync with the kernel as much as
>> possible. Does the kernel also use "dev" instead of "nand" here?
>
> Yes I based this on
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/armada-39x.dtsi
> I haven't got round to porting the kernel to my board so I imagine a
> similar change will be required to armada-38x.dtsi in the kernel.
>

I've sent a kernel patch for the armada-38x[1] so perhaps we should
just drop this one and sync up if/when the kernel patch is accepted.

[1] - http://lists.infradead.org/pipermail/linux-arm-kernel/2016-August/451027.html