[U-Boot] [PATCH] tegra: implement pinmux_avoid_func()

[Simon Glass]

Hi Stephen,

On Tue, Jan 22, 2013 at 4:21 PM, Stephen Warren <swarren at wwwdotorg.org> wrote:
> On 01/22/2013 05:03 PM, Simon Glass wrote:
>> Hi Stephen,
>>
>> On Tue, Jan 22, 2013 at 2:14 PM, Stephen Warren <swarren at wwwdotorg.org> wrote:
>>> On 01/22/2013 02:42 PM, Simon Glass wrote:
>>>> Hi Stephen,
>>>>
>>>> On Tue, Jan 22, 2013 at 1:26 PM, Stephen Warren <swarren at wwwdotorg.org> wrote:
>>>>> On 01/22/2013 02:13 PM, Simon Glass wrote:
>>>>>> Hi Stephen,
>>>>>>
>>>>>> On Tue, Jan 22, 2013 at 8:21 AM, Stephen Warren <swarren at wwwdotorg.org> wrote:
>>>>>>> From: Stephen Warren <swarren at nvidia.com>
>>>>>>>
>>>>>>> This selects the "safe" (non-conflicting) mux function for a pin group
>>>>>>> if the current setting matches the specified function.
>>>>>>>
>>>>>>> Many signals can be routed to or from multiple different groups. Each
>>>>>>> signal must be routed to or from only a single group at a given time.
>>>>>>> Hence, if we program a particular group for a function, we must ensure
>>>>>>> no other group is programmed to that same function first. This API
>>>>>>> makes this easy.
>>>>>>
>>>>>> What is the intended use of this function? (sorry, yes, I am confused :-)
>>>>>
>>>>> It's a safer way of doing this:
>>>>> "tegra: pinmux: fix FUNCMUX_NDFLASH_KBC_8_BIT"
>>>>> http://lists.denx.de/pipermail/u-boot/2013-January/144612.html
>>>>>
>>>>> i.e. it address the concerns I raised here:
>>>>> http://lists.denx.de/pipermail/u-boot/2013-January/144713.html
>>>>>
>>>>
>>>> OK thank you. So is your function only intended for use with T20?
>>>
>>> No, I imagine that it should be used for all Tegras; I just wrote it
>>> long enough ago that there was only Tegra20 at the time. I assume that
>>> if Lucas wants to use this function as a pre-cursor to his NAND pinmux
>>> change, he'll update it for whatever Tegra versions are checked in at
>>> the time first.
>>>
>> Thanks, I get it.
>>
>> Should Lucas consider adding a warning or some sort of indication that
>> the function did nothing?
>
> Do you mean on Tegra30 where it isn't implemented yet (no - I'd expect
> to see this implemented instead) or when the current function programmed
> into HW already doesn't match the value one is trying to avoid (no - I'd
> expect this to be quite common).
>

The latter - ok that's fine.

Regards,
Simon