Re: [RFC PATCH v2 4/4] sensehat: Add device tree overlay (do not merge)

[Matthias Brugger <mbrugger@suse.com>]

On 20/08/2021 20:08, Charles Mirabile wrote:
> This patch is an RFC. The overlay included here is suitable for the
> Sense HAT but we are not sure where overlays like this should go, or if we
> should even include it, because the Raspberry Pi kernel tree already
> includes that device tree blob that this was based on and most
> distributions for the Raspberry Pi include those blobs.
> 
> The overlay is just in the root of the source tree since we did not know
> where to put it so this patch should not be merged in this state.
> 
> Signed-off-by: Charles Mirabile <cmirabil@redhat.com>
> Signed-off-by: Mwesigwa Guma <mguma@redhat.com>
> Signed-off-by: Joel Savitz <jsavitz@redhat.com>
> ---
>   sensehat.dtbs | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 51 insertions(+)
>   create mode 100644 sensehat.dtbs
> 
> diff --git a/sensehat.dtbs b/sensehat.dtbs
> new file mode 100644
> index 000000000000..3f1c12c8f75f
> --- /dev/null
> +++ b/sensehat.dtbs
> @@ -0,0 +1,51 @@
> +/dts-v1/;
> +
> +/ {
> +	compatible = "brcm,bcm2835";
> +
> +	fragment@0 {
> +		target = <0xffffffff>;
> +
> +		__overlay__ {
> +			#address-cells = <0x01>;
> +			#size-cells = <0x00>;
> +			status = "okay";
> +
> +			sensehat@46 {
> +				compatible = "raspberrypi,sensehat";
> +				reg = <0x46>;
> +				keys-int-gpios = <0xffffffff 0x17 0x01>;
> +				status = "okay";
> +			};
> +
> +			lsm9ds1-magn@1c {
> +				compatible = "st,lsm9ds1-magn";
> +				reg = <0x1c>;
> +				status = "okay";
> +			};
> +
> +			lsm9ds1-accel6a {
> +				compatible = "st,lsm9ds1-accel";
> +				reg = <0x6a>;
> +				status = "okay";
> +			};
> +
> +			lps25h-press@5c {
> +				compatible = "st,lps25h-press";
> +				reg = <0x5c>;
> +				status = "okay";
> +			};
> +
> +			hts221-humid@5f {
> +				compatible = "st,hts221-humid\0st,hts221";

Isn't "st,hts221" good enough?

> +				reg = <0x5f>;
> +				status = "okay";
> +			};
> +		};
> +	};
> +
> +	__fixups__ {
> +		i2c1 = "/fragment@0:target:0";
> +		gpio = "/fragment@0/__overlay__/sensehat@46:keys-int-gpios:0";
> +	};
> +};
> 

As Nicolas said, yaml bindings are a must. The overlay can be added as for 
convenience to the series but it should be made clear that it is not supposed to 
be upstreamed.

Regards,
Matthias