Re: [PATCH V2] arm64: dts: imx8mp: Add NPU Node

Alexander Stein
2023-10-23T13:23:49Z

Hi Adam,

thanks for the update.

Am Sonntag, 22. Oktober 2023, 18:19:10 CEST schrieb Adam Ford:
> The NPU is based on the Vivante GC8000 and its power-domain
> is controlled my pgc_mlmix. Since the power-domain uses
> some of these clocks, setup the clock parent and rates
> inside the power-domain, and add the NPU node.
>
> The data sheet states the CLK_ML_AHB should be 300MHz for
> nominal, but 800MHz clock will divide down to 266 instead.
> Boards which operate in over-drive mode should update the
> clocks on their boards accordingly. When the driver loads,
> the NPU numerates as:
>
> etnaviv-gpu 38500000.npu: model: GC8000, revision: 8002

There seems to be some race condition upon GPU/NPU detection. Sometimes I get
these messages:
[ 1.338100] etnaviv-gpu 38000000.gpu: model: GC7000, revision: 6204
[ 1.344469] etnaviv-gpu 38008000.gpu: model: GC520, revision: 5341
[ 1.350748] etnaviv-gpu 38500000.npu: model: GC0, revision: 0
[ 1.356514] etnaviv-gpu 38500000.npu: Unknown GPU model

Sometimes I see GC8000 being detected as you have written. Despite that the
patch itself looks good.
Reviewed-by: Alexander Stein <alexander.stein@ew.tq-group.com>

>
> Signed-off-by: Adam Ford <aford173@gmail.com>
> ---
>
> V2: Move the clock parent and rate assignments to the ppc_mlmix node
> since clock parents should be configured before they are used,
> and pgc_mlmix uses them first.
> Slow the clock rates down to confirm to nominal mode instead of
> overdrive mode.
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> b/arch/arm64/boot/dts/freescale/imx8mp.dtsi index
> c9a610ba4836..a18b9ba98ea2 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> @@ -887,6 +887,15 @@ pgc_mlmix: power-domain@24 {
> clocks = <&clk
IMX8MP_CLK_ML_AXI>,
> <&clk
IMX8MP_CLK_ML_AHB>,
> <&clk
IMX8MP_CLK_NPU_ROOT>;
> + assigned-clocks =
<&clk IMX8MP_CLK_ML_CORE>,
> +
<&clk IMX8MP_CLK_ML_AXI>,
> +
<&clk IMX8MP_CLK_ML_AHB>;
> + assigned-clock-
parents = <&clk IMX8MP_SYS_PLL1_800M>,
> +
<&clk IMX8MP_SYS_PLL1_800M>,
> +
<&clk IMX8MP_SYS_PLL1_800M>;
> + assigned-clock-
rates = <800000000>,
> +
<800000000>,
> +
<300000000>;
> };
> };
> };
> @@ -2012,6 +2021,18 @@ vpumix_blk_ctrl: blk-ctrl@38330000 {
> interconnect-names = "g1", "g2", "vc8000e";
> };
>
> + npu: npu@38500000 {
> + compatible = "vivante,gc";
> + reg = <0x38500000 0x200000>;
> + interrupts = <GIC_SPI 13 IRQ_TYPE_LEVEL_HIGH>;
> + clocks = <&clk IMX8MP_CLK_NPU_ROOT>,
> + <&clk IMX8MP_CLK_NPU_ROOT>,
> + <&clk IMX8MP_CLK_ML_AXI>,
> + <&clk IMX8MP_CLK_ML_AHB>;
> + clock-names = "core", "shader", "bus", "reg";
> + power-domains = <&pgc_mlmix>;
> + };
> +
> gic: interrupt-controller@38800000 {
> compatible = "arm,gic-v3";
> reg = <0x38800000 0x10000>,

--
TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
Amtsgericht München, HRB 105018
Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider