Hi Jan,
> > +Required properties:
> > +- compatible: "i2c-demux-pinctrl"
> > +- i2c-parent: List of phandles of I2C masters available for selection. The first
> > + one will be used as default.
> > +- i2c-bus-name: The name of this bus. Also needed as pinctrl-name for the I2C
> > + parents.
> [...]
> > + i2chdmi: i2c@8 {
> > + compatible = "i2c-demux-pinctrl";
> > + i2c-parent = <&gpioi2c>, <&iic2>, <&i2c2>;
> > + i2c-bus-name = "i2c-hdmi";
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> [...]
> > + gpioi2c: i2c@9 {
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > + compatible = "i2c-gpio";
> [...]
> > +&i2c2 {
> > + pinctrl-0 = <&i2c2_pins>;
> > + pinctrl-names = "i2c-hdmi";
> > +
> > + clock-frequency = <100000>;
> > +};
> [...]
> > +&iic2 {
> > + pinctrl-0 = <&iic2_pins>;
> > + pinctrl-names = "i2c-hdmi";
> > +
> > + clock-frequency = <100000>;
> > +};
> [...]
>
> It seems that the demux-pinctrl driver reconfigures the pinctrl settings
> for the parent devices. I would have expected to have alternative
> pinctrl state on the demux node support switching the same external pins
> between the different controllers. Wouldn't it be possible to have
> pinctrl conflicts between &i2c2_pins and &iic2_pins otherwise?
I don't think so. Before i2c2 is enabled, iic2 gets disabled (status =
"disabled" via OF_DYNAMIC) and thus the pins get free. Doing it this
way, you could even have something like this:
pinctrl-0 = <&iic2_pins>, <&iic2_c_pins>;
pinctrl-names = "i2c-hdmi", "i2c-sensors";
which allows you to demux this controller to this or that bus. I haven't
tested this, though.
Wolfram
Attachment:
signature.asc
Description: Digital signature
