Re: [PATCH 3/4] arm64: dts: qcom: sc7280: Factor out Chrome common fragment

From: Stephen Boyd
Date: Fri Jan 14 2022 - 01:15:15 EST


Quoting Douglas Anderson (2022-01-13 16:43:02)
> This factors out a device tree fragment from some sc7280 device
> trees. It represents the device tree bits that should be included for
> "Chrome" based sc7280 boards. On these boards the bootloader (Coreboot
> + Depthcharge) configures things slightly different than the
> bootloader that Qualcomm provides. The modem firmware on these boards
> also works differently than on other Qulacomm products and thus the
> reserved memory map needs to be adjusted.
>
> NOTES:
> - This is _not_ quite a no-op change. The "herobrine" and "idp"
> fragments here were different and it looks like someone simply
> forgot to update the herobrine version. This updates a few numbers
> to match IDP. This will also cause the `pmk8350_pon` to be disabled
> on idp/crd, which I belive is a correct change.
> - At the moment this assumes LTE skus. Once it's clearer how WiFi SKUs
> will work (how much of the memory map they can reclaim) we may add
> an extra fragment that will rejigger one way or the other.
>
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> ---

Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>

One comment below.

> diff --git a/arch/arm64/boot/dts/qcom/sc7280-chrome-common.dtsi b/arch/arm64/boot/dts/qcom/sc7280-chrome-common.dtsi
> new file mode 100644
> index 000000000000..9d4f25f77152
> --- /dev/null
> +++ b/arch/arm64/boot/dts/qcom/sc7280-chrome-common.dtsi
> @@ -0,0 +1,97 @@
[...]
> +
> +/* Modem setup is different on Chrome setups than typical Qualcomm setup */
> +&remoteproc_mpss {
> + status = "okay";
> + compatible = "qcom,sc7280-mss-pil";
> + iommus = <&apps_smmu 0x124 0x0>, <&apps_smmu 0x488 0x7>;
> + memory-region = <&mba_mem &mpss_mem>;

I'd prefer this be

memory-region = <&mba_mem>, <&mpss_mem>;

so that we know mpss_mem isn't an "argument" or cell for mba_mem. I see
that this is just moving around in this patch though so probably can be
done in a followup.

> +};
> +
> +/* Increase the size from 2.5MB to 8MB */
> +&rmtfs_mem {
> + reg = <0x0 0x9c900000 0x0 0x800000>;
> +};