Hi Nikolaus,
On Wed, Nov 24, 2021 at 5:31 PM H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> wrote:
> > Am 24.11.2021 um 17:21 schrieb Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>:
> > On Wed, Nov 24, 2021 at 5:19 PM H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> wrote:
> >>> Am 23.11.2021 um 21:10 schrieb Paul Cercueil <paul@xxxxxxxxxxxxxxx>:
> >>> Le mar., nov. 23 2021 at 19:13:59 +0100, H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> a écrit :
> >>>> + assigned-clock-rates = <48000000>, <0>, <54000000>, <0>, <27000000>;
> >>>> };
> >>>> &tcu {
> >>>> @@ -509,6 +534,19 @@ pins_i2c4: i2c4 {
> >>>> bias-disable;
> >>>> };
> >>>> + pins_hdmi_ddc: hdmi_ddc {
> >>>> + function = "hdmi-ddc";
> >>>> + groups = "hdmi-ddc";
> >>>> + bias-disable;
> >>>> + };
> >>>> +
> >>>> + /* switch to PF25 as gpio driving DDC_SDA low */
> >>>> + pins_hdmi_ddc_unwedge: hdmi_ddc {
> >>>> + function = "hdmi-ddc";
> >>>> + groups = "hdmi-ddc";
> >>>> + bias-disable;
> >>>> + };
> >>>
> >>> Your pins_hdmi_ddc and pins_hdmi_ddc_unwedge are the exact same? You could just use the former and pass it to both pinctrl-0 and pinctrl-1.
> >>
> >> This was forgotten to remove. We do not make use of the unwedge feature because I could not find out how to use pinctrl to switch this to gpio25 and drive it low.
> >
> > Using gpio-hog?
>
> well, AFAIR it activates the gpio permanently and is a propery of the gpio controller and not of pinmux.
Yes, hogs are permanently (ignoring DT overlay tricks).
> The driver assumes it can use pinmux state switching to drive the DDC_SDA line low on demand.
Add an optional wedge-gpios property for switching?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
