On Fri, Mar 6, 2015 at 3:37 AM, Linus Walleij <linus.walleij@xxxxxxxxxx> wrote:
> On Tue, Feb 24, 2015 at 3:15 AM, Andrew Bresticker
> <abrestic@xxxxxxxxxxxx> wrote:
>
>> Add a device-tree binding document for the pin controller present
>> on the IMG Pistachio SoC.
>>
>> Signed-off-by: Damien Horsley <Damien.Horsley@xxxxxxxxxx>
>> Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
> (...)
>> +Note that the GPIO bank sub-nodes *must* be listed in order.
>
> Usually we use aliases to mark the order of things. e.g.:
>
> aliases {
> gpio0 = &gpio0;
> gpio1 = &gpio1;
> gpio2 = &gpio2;
> ethernet0 = ð0;
> ethernet1 = ð1;
> };
>
> (arch/arm/boot/dts/armada-375.dtsi)
Ok.
>> +Required properties for pin configuration sub-nodes:
>> +----------------------------------------------------
>> + - pins: List of pins to which the configuration applies. See below for a
>> + list of possible pins.
>> +
>> +Optional properties for pin configuration sub-nodes:
>> +----------------------------------------------------
>> + - function: Mux function for the specified pins. This is not applicable for
>> + non-MFIO pins. See below for a list of valid functions for each pin.
>> + - bias-high-impedance: Enable high-impedance mode.
>> + - bias-pull-up: Enable weak pull-up.
>> + - bias-pull-down: Enable weak pull-down.
>> + - bias-bus-hold: Enable bus-keeper mode.
>> + - drive-strength: Drive strength in mA. Supported values: 2, 4, 8, 12.
>> + - input-schmitt-enable: Enable Schmitt trigger.
>> + - input-schmitt-disable: Disable Schmitt trigger.
>> + - slew-rate: Slew rate control. 0 for slow, 1 for fast.
>
> We actually haven't specified that function+pins is a valid pattern,
> a lot of drivers just started doing that :(
>
> function+groups is documented for muxing.
>
> group + config opts is documented for config.
>
> Please consider patching the generic bindings to reflect this
> mux use of pins... We need to discuss it.
Sure, I can update that documentation.
Thanks,
Andrew
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