Re: [PATCH] arm64: dts: renesas: ulcb-kf: add 9-asix sensor device

[Geert Uytterhoeven]

Hi Nikita,

Thanks for your patch!

On Wed, Jan 12, 2022 at 9:52 PM Nikita Yushchenko
<nikita.yoush@xxxxxxxxxxxxxxxxxx> wrote:
> This adds nodes for lsm9ds0 sensor installed on the KF board.
>
> With this patch, the sensor data becomes available over iio sysfs
> interface.
>
> Interrupt definition is not added yet, because the interrupt lines of
> lsm9ds0 are pulled to VCC on the board, which implies need for
> active-low configuration. But st_sensors drivers currently can't work
> with active-low interrupts on this chip.

That's unfortunate, as DT describes hardware, not limitations of the
software stack.

> Signed-off-by: Nikita Yushchenko <nikita.yoush@xxxxxxxxxxxxxxxxxx>

> --- a/arch/arm64/boot/dts/renesas/ulcb-kf.dtsi
> +++ b/arch/arm64/boot/dts/renesas/ulcb-kf.dtsi
> @@ -66,6 +66,13 @@ hdmi_3v3: regulator-hdmi-3v3 {
>                 regulator-max-microvolt = <3300000>;
>         };
>
> +       accel_3v3: regulator-acc-3v3 {
> +               compatible = "regulator-fixed";
> +               regulator-name = "accel-3v3";
> +               regulator-min-microvolt = <3300000>;
> +               regulator-max-microvolt = <3300000>;
> +       };
> +
>         hdmi1-out {
>                 compatible = "hdmi-connector";
>                 type = "a";
> @@ -208,6 +215,22 @@ pcm3168a_endpoint_c: endpoint {
>                                         };
>                                 };
>                         };
> +
> +                       lsm9ds0_acc_mag@1d {

Please use standard node names: accelerometer@1d?

> +                               compatible = "st,lsm9ds0-imu";
> +                               reg = <0x1d>;
> +
> +                               vdd-supply = <&accel_3v3>;
> +                               vddio-supply = <&accel_3v3>;

According to the bindings, the supplies are not required, so you can
leave them out? Or are the bindings wrong?
(The bindings also say "interrupts: maxItems 2", while the "interrupts:
 description" says up to three interrupts, doh...)

> +                       };
> +
> +                       lsm9ds0_gyro@6b {

gyroscope@6b?

> +                               compatible = "st,lsm9ds0-gyro";
> +                               reg = <0x6b>;
> +
> +                               vdd-supply = <&accel_3v3>;
> +                               vddio-supply = <&accel_3v3>;
> +                       };
>                 };
>         };

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