Re: [PATCH V2 5/6] dt: Document Tegra20/30 pinctrl binding

[Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>]

On 03/21/2012 03:19 AM, Dong Aisheng wrote:
> On Wed, Mar 21, 2012 at 01:44:38AM +0800, Stephen Warren wrote:
>> Define a new binding for the Tegra pin controller, which is capable of
>> defining all aspects of desired pin multiplexing and pin configuration.
>> This is all based on the new common pinctrl bindings.
>>
>> Add Tegra30 binding based on Tegra20 binding.
>>
>> Add some basic stuff that was missing before:
>> * How many and what reg property entries must be provided.
>> * An example.
>>
>> Signed-off-by: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
>> ---
> ........
>> +Example board file extract:
>> +
>> +	pinctrl@70000000 {
>> +		sdio4_default {
>> +			atb {
>> +				nvidia,pins = "atb", "gma", "gme";
>> +				nvidia,function = "sdio4";
>> +				nvidia,pull = <0>;
>> +				nvidia,tristate = <0>;
>> +			};
>> +		};
>> +	};
>> +
>> +	sdhci@c8000600 {
>> +		pinctrl-names = "default";
>> +		pinctrl-0 = <&sdio4_default>;
>
> A typo error? sdio4_default is not a phandle.

Yes.

>> +Example board file extract:
>> +
>> +	pinctrl@70000000 {
>> +		sdmmc4_default: pinmux {
>> +			sdmmc4_clk_pcc4 {
>> +				nvidia,pins =	"sdmmc4_clk_pcc4",
>> +						"sdmmc4_rst_n_pcc3";
>> +				nvidia,function = "sdmmc4";
>> +				nvidia,pull = <0>;
>> +				nvidia,tristate = <0>;
>> +			};
>> +			sdmmc4_dat0_paa0 {
>> +				nvidia,pins =	"sdmmc4_dat0_paa0",
>> +						"sdmmc4_dat1_paa1",
>> +						"sdmmc4_dat2_paa2",
>> +						"sdmmc4_dat3_paa3",
>> +						"sdmmc4_dat4_paa4",
>> +						"sdmmc4_dat5_paa5",
>> +						"sdmmc4_dat6_paa6",
>> +						"sdmmc4_dat7_paa7";
>> +				nvidia,function = "sdmmc4";
>> +				nvidia,pull = <2>;
>> +				nvidia,tristate = <0>;
>
> It seems it does not support per pin config for tegra30 and we have to
> separate them in different nodes with same group config value, right?

Sorry, I don't understand the question.

On Tegra30, pin mux selection and some pin configuration parameters are
per-pin. Other pin configuration parameters are per-group. The pinctrl
driver defines groups for:

* Each pin (for per-pin properties)
* Each group that has non-per-pin configuration parameters.

You can use either/both sets of groups in the .dts file (i.e. in the
nvidia,pins property).

You'd never end up with a single node that mixes the "per-pin" group
names and "non-per-pin" group names, simply because there are no
properties that can be applied to groups of both types in hardware.