Re: [PATCH] pinctrl: Support pin that does not support configuration option

[Michael Nazzareno Trimarchi]

Hi Fabio

On Fri, Feb 12, 2021 at 9:31 AM Michael Nazzareno Trimarchi
<michael@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hi
>
> On Fri, Feb 12, 2021 at 9:26 AM Linus Walleij <linus.walleij@xxxxxxxxxx> wrote:
> >
> > On Mon, Feb 1, 2021 at 12:54 PM Michael Nazzareno Trimarchi
> > <michael@xxxxxxxxxxxxxxxxxxxx> wrote:
> > > On Mon, Feb 1, 2021 at 12:47 PM Fabio Estevam <festevam@xxxxxxxxx> wrote:
> > > >
> > > > Hi Michael,
> > > >
> > > > On Sat, Jan 30, 2021 at 5:21 AM Michael Trimarchi
> > > > <michael@xxxxxxxxxxxxxxxxxxxx> wrote:
> > > > >
> > > > > Some of the iMX25 pins have not an associated configuration register so
> > > > > when they are configured the standard way through the device tree the
> > > > > kernel complains with:
> > > > >
> > > > > imx25-pinctrl 43fac000.iomuxc: Pin(MX25_PAD_EXT_ARMCLK) does not support
> > > > > config function
> > > >
> > > > Could you please share your device tree that causes this warning?
> > > >
> > > > Shouldn't you pass 0x80000000 in the devicetree for this pad then?
> > > >
> > > > 0x80000000 means that the kernel should not touch the PAD_CTL register
> > > > and use the default configuration from the bootloader/POR.
> > >
> > > arch/arm/boot/dts/imx25-lisa.dts:
> > > MX25_PAD_EXT_ARMCLK__GPIO_3_15  0x80000000
> > >
> > > The problem that exists pad that can be muxed but not configured
> >
> > Did you reach any conclusion on this?
> >
> > I need Fabio's consent to apply the patch, but it seems maybe the
> > DTS should be changed instead?
> >
>
> Let me re-check with the latest linux code. I did not find any change
> there. It's on my side
> now

Looking at the code (I will ask to check on real hw) seems that
conf_reg is -1 when there is no conf_reg.
the pinmux core set_state just calls the pin_config_set and one pin
can have the mux supported and the config
not supported. And imx25 has several of them that are only muxed.
Seems that this NO_CTL_PAD is something
that is nxp

 clk_osc_audio: clk-osc-audio {
                compatible = "gpio-gate-clock";
                pinctrl-names = "default";
                pinctrl-0 = <&pinctrl_clk26mhz_osc>;
                clocks = <&clksis>;
                #clock-cells = <0>;
                enable-gpios = <&gpio3 15 GPIO_ACTIVE_LOW>;
        };

this is my use case
 pinctrl_clk26mhz_osc: clk26mhzosc {
                        fsl,pins = <
                                MX25_PAD_EXT_ARMCLK__GPIO_3_15  0x80000000
                        >;
                };

Michael




>
> Michael
>
> > Yours,
> > Linus Walleij
>
>
>
> --
> Michael Nazzareno Trimarchi
> Amarula Solutions BV
> COO Co-Founder
> Cruquiuskade 47 Amsterdam 1018 AM NL
> T. +31(0)851119172
> M. +39(0)3479132170
> [`as] https://www.amarulasolutions.com



-- 
Michael Nazzareno Trimarchi
Amarula Solutions BV
COO Co-Founder
Cruquiuskade 47 Amsterdam 1018 AM NL
T. +31(0)851119172
M. +39(0)3479132170
[`as] https://www.amarulasolutions.com