Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control

[Laxman Dewangan <ldewangan@nvidia.com>]

On Friday 15 April 2016 10:05 PM, Stephen Warren wrote:
> On 04/12/2016 08:56 AM, Laxman Dewangan wrote:
>> NVIDIA Tegra210 supports the IO pads which can operate at 1.8V
>> or 3.3V I/O voltage levels. Also IO pads can be configured for
>> power down state if it is not in used. SW needs to configure the
>> voltage level of IO pads based on IO rail voltage and its power
>> state based on platform usage.
>>
>> Add DT binding document for detailing the DT properties for
>> configuring IO pads voltage levels and its power state.
>
> I hope that we only intend to use this in the case where Linux must 
> make dynamic changes to the IO voltage (e.g. SD cards switching 
> between speeds).
>
> All static settings, and good boot defaults, should be set up by 
> system FW. Perhaps not all FW does this on Tegra210 platforms:-( I 
> hope that on future chips, the same FW that sets up the static pinmux 
> sets up the static IO voltage configuration, in exactly the same way.

Exactly yes.