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

[Stefan Roese]

Hi Chris,

On 24.08.2016 02:24, Chris Packham wrote:
> 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

Yes, this is better. I'll drop the patch for now and will make sure
that we sync with the kernel at some later time. Perhaps we even
have a pinctrl driver for A38x at that time... ;)

Thanks,
Stefan