[PATCH v4 2/3] board: phytec: imx93: Add eeprom-based hardware introspection

[Christoph Stoidner]

Hi Stefan,

On Do, 2024-11-21 at 11:12 +0100, Stefan Wahren wrote:
> Hi Christoph,
> 
> Am 20.11.24 um 17:31 schrieb Christoph Stoidner:
> 

[...]

> > 
> > diff --git a/arch/arm/dts/imx93-phyboard-segin-u-boot.dtsi
> > b/arch/arm/dts/imx93-phyboard-segin-u-boot.dtsi
> > index 6897c91f4d..702d86f4e0 100644
> > --- a/arch/arm/dts/imx93-phyboard-segin-u-boot.dtsi
> > +++ b/arch/arm/dts/imx93-phyboard-segin-u-boot.dtsi
> > @@ -139,6 +139,13 @@
> >   &usdhc1 {
> >         bootph-pre-ram;
> >         bootph-some-ram;
> > +       /*
> > +        * Remove pinctrl assignments once they are added to imx93-
> > phycore-som.dtsi
> > +        */
> > +       pinctrl-names = "default", "state_100mhz", "state_200mhz";
> > +       pinctrl-0 = <&pinctrl_usdhc1>;
> > +       pinctrl-1 = <&pinctrl_usdhc1_100mhz>;
> > +       pinctrl-2 = <&pinctrl_usdhc1_200mhz>;
> >   };
> > 
> >   &usdhc2 {
> > @@ -215,6 +222,48 @@
> >                         MX93_PAD_ENET2_RD3__GPIO4_IO27             
> >      0x31e
> >                 >;
> >         };
> > +
> > +       /*
> > +        * Remove pinctrl_usdhc1_100mhz and pinctrl_usdhc1_200mhz
> > once they
> > +        * are added to imx93-phycore-som.dtsi
> > +        */
> > +       /* need to config the SION for data and cmd pad, refer to
> > ERR052021 */
> > +       pinctrl_usdhc1_100mhz: usdhc1-100mhzgrp {
> > +               bootph-pre-ram;
> > +               bootph-some-ram;
> > +               fsl,pins = <
> > +                       MX93_PAD_SD1_CLK__USDHC1_CLK            0x1
> > 7be
> > +                       MX93_PAD_SD1_CMD__USDHC1_CMD            0x4
> > 000139e
> > +                       MX93_PAD_SD1_DATA0__USDHC1_DATA0        0x4
> > 000138e
> > +                       MX93_PAD_SD1_DATA1__USDHC1_DATA1        0x4
> > 000139e
> > +                       MX93_PAD_SD1_DATA2__USDHC1_DATA2        0x4
> > 00013be
> Could you please explain why the pin configuration for 100 MHz of
> DATA0
> & DATA2 is different from the other data pins?

The difference in the values is due to different drive-strength
settings per pin. The values are the result of measurements we
did for the eMMC interface. There, we adjusted each pin's
drive-strength to get it's best signal quality.

Regards,
Christoph

> > +                       MX93_PAD_SD1_DATA3__USDHC1_DATA3        0x4
> > 000139e
> > +                       MX93_PAD_SD1_DATA4__USDHC1_DATA4        0x4
> > 000139e
> > +                       MX93_PAD_SD1_DATA5__USDHC1_DATA5        0x4
> > 000139e
> > +                       MX93_PAD_SD1_DATA6__USDHC1_DATA6        0x4
> > 000139e
> > +                       MX93_PAD_SD1_DATA7__USDHC1_DATA7        0x4
> > 000139e
> > +                       MX93_PAD_SD1_STROBE__USDHC1_STROBE      0x1
> > 79e
> > +               >;
> > +       };
> > +
> > +       /* need to config the SION for data and cmd pad, refer to
> > ERR052021 */
> > +       pinctrl_usdhc1_200mhz: usdhc1-200mhzgrp {
> > +               bootph-pre-ram;
> > +               bootph-some-ram;
> > +               fsl,pins = <
> > +                       MX93_PAD_SD1_CLK__USDHC1_CLK            0x1
> > 7be
> > +                       MX93_PAD_SD1_CMD__USDHC1_CMD            0x4
> > 000139e
> > +                       MX93_PAD_SD1_DATA0__USDHC1_DATA0        0x4
> > 000139e
> > +                       MX93_PAD_SD1_DATA1__USDHC1_DATA1        0x4
> > 00013be
> > +                       MX93_PAD_SD1_DATA2__USDHC1_DATA2        0x4
> > 00013be
> > +                       MX93_PAD_SD1_DATA3__USDHC1_DATA3        0x4
> > 00013be
> > +                       MX93_PAD_SD1_DATA4__USDHC1_DATA4        0x4
> > 00013be
> > +                       MX93_PAD_SD1_DATA5__USDHC1_DATA5        0x4
> > 00013be
> > +                       MX93_PAD_SD1_DATA6__USDHC1_DATA6        0x4
> > 00013be
> > +                       MX93_PAD_SD1_DATA7__USDHC1_DATA7        0x4
> > 00013be
> > +                       MX93_PAD_SD1_STROBE__USDHC1_STROBE      0x1
> > 79e
> > +               >;
> > +       };
> >   };
> >