RE: [PATCH V2 3/3] arm64: dts: add initial device tree for Thunder Bay SoC

["Demakkanavar, Kenchappa" <kenchappa.demakkanavar@intel.com>]

Hi Rob,

Thanks for your time in providing feedback. 

Please find my reply in-lined below.

Thanks & Regards,
Kenchappa S. D.

> -----Original Message-----
> From: Rob Herring <robh@kernel.org>
> Sent: Friday, July 30, 2021 1:23 AM
> To: Demakkanavar, Kenchappa <kenchappa.demakkanavar@intel.com>
> Cc: will@kernel.org; linux-arm-kernel@lists.infradead.org; linux-
> kernel@vger.kernel.org; devicetree@vger.kernel.org; dinguyen@kernel.org;
> Zhou, Furong <furong.zhou@intel.com>; kris.pan@linux.intel.com; Pan, Kris
> <kris.pan@intel.com>; mgross@linux.intel.com; Gross, Mark
> <mark.gross@intel.com>
> Subject: Re: [PATCH V2 3/3] arm64: dts: add initial device tree for Thunder Bay
> SoC
> 
> On Tue, Jul 20, 2021 at 10:52:49AM +0530,
> kenchappa.demakkanavar@intel.com wrote:
> > From: "Demakkanavar, Kenchappa" <kenchappa.demakkanavar@intel.com>
> >
> > Add initial device tree for Intel Movidius SoC code-named Thunder Bay.
> >
> > This initial DT includes nodes for 4 CPU clusters with 4 Cortex-A53
> > cores per cluster, UARTs, GIC, ARM Timer and PSCI.
> 
> Make sure you run 'make dtbs_check' on these.
Sure. Will post clean patches in next version.

> 
> There shouldn't be any dtc warnings and or undocumented compatible warnings
> at a minimum.
Sure. Will post clean patches in next version.

> 
> > thunderbay-soc.dtsi   - Thunder Bay SoC dtsi file
> > hddl_hybrid_4s.dts    - Thunder Bay full configuration board dts
> > 			with 4 VPU processors
> > hddl_hybrid_2s_02.dts - Thunder Bay prime configuration board dts with
> > 			2 VPU processors (slice 0 and slice 2 enabled)
> > hddl_hybrid_2s_03.dts - Thunder Bay prime configuration board dts with
> > 			2 VPU processors (slice 0 and slice 3 enabled)
> > hddl_hybrid_2s_12.dts - Thunder Bay prime configuration board dts with
> > 			2 VPU processors (slice 1 and slice 2 enabled)
> > hddl_hybrid_2s_13.dts - Thunder Bay prime configuration board dts with
> > 			2 VPU processors (slice 1 and slice 3 enabled)
> >
> > Signed-off-by: Demakkanavar, Kenchappa
> > <kenchappa.demakkanavar@intel.com>
> > ---
> >  MAINTAINERS                                     |   2 +
> >  arch/arm64/boot/dts/intel/Makefile              |   6 +
> >  arch/arm64/boot/dts/intel/hddl_hybrid_2s_02.dts |  43 +++++
> > arch/arm64/boot/dts/intel/hddl_hybrid_2s_03.dts |  43 +++++
> > arch/arm64/boot/dts/intel/hddl_hybrid_2s_12.dts |  43 +++++
> > arch/arm64/boot/dts/intel/hddl_hybrid_2s_13.dts |  43 +++++
> >  arch/arm64/boot/dts/intel/hddl_hybrid_4s.dts    |  54 ++++++
> >  arch/arm64/boot/dts/intel/thunderbay-soc.dtsi   | 243
> ++++++++++++++++++++++++
> >  8 files changed, 477 insertions(+)
> >  create mode 100644 arch/arm64/boot/dts/intel/hddl_hybrid_2s_02.dts
> >  create mode 100644 arch/arm64/boot/dts/intel/hddl_hybrid_2s_03.dts
> >  create mode 100644 arch/arm64/boot/dts/intel/hddl_hybrid_2s_12.dts
> >  create mode 100644 arch/arm64/boot/dts/intel/hddl_hybrid_2s_13.dts
> >  create mode 100644 arch/arm64/boot/dts/intel/hddl_hybrid_4s.dts
> >  create mode 100644 arch/arm64/boot/dts/intel/thunderbay-soc.dtsi
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS index 041f9a0..68317f0 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -1996,6 +1996,8 @@ ARM/INTEL THUNDERBAY ARCHITECTURE
> >  M:	Demakkanavar, Kenchappa <kenchappa.demakkanavar@intel.com>
> >  S:	Maintained
> >  F:	Documentation/devicetree/bindings/arm/intel,thunderbay.yaml
> > +F:	arch/arm64/boot/dts/intel/hddl*
> > +F:	arch/arm64/boot/dts/intel/thunderbay-soc.dtsi
> >
> >  ARM/INTEL XSC3 (MANZANO) ARM CORE
> >  M:	Lennert Buytenhek <kernel@wantstofly.org>
> > diff --git a/arch/arm64/boot/dts/intel/Makefile
> > b/arch/arm64/boot/dts/intel/Makefile
> > index 0b54774..767b74b 100644
> > --- a/arch/arm64/boot/dts/intel/Makefile
> > +++ b/arch/arm64/boot/dts/intel/Makefile
> > @@ -3,3 +3,9 @@ dtb-$(CONFIG_ARCH_INTEL_SOCFPGA) +=
> socfpga_agilex_socdk.dtb \
> >  				socfpga_agilex_socdk_nand.dtb \
> >  				socfpga_n5x_socdk.dtb
> >  dtb-$(CONFIG_ARCH_KEEMBAY) += keembay-evm.dtb
> > +
> > +dtb-$(CONFIG_ARCH_THUNDERBAY) += hddl_hybrid_4s.dtb \
> > +				 hddl_hybrid_2s_02.dtb \
> > +				 hddl_hybrid_2s_03.dtb \
> > +				 hddl_hybrid_2s_12.dtb \
> > +				 hddl_hybrid_2s_13.dtb
> > diff --git a/arch/arm64/boot/dts/intel/hddl_hybrid_2s_02.dts
> > b/arch/arm64/boot/dts/intel/hddl_hybrid_2s_02.dts
> > new file mode 100644
> > index 0000000..f907ddd
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/intel/hddl_hybrid_2s_02.dts
> > @@ -0,0 +1,43 @@
> > +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
> > +/*
> > + * Copyright (c) 2021 Intel Corporation.
> > + *
> > + * Device tree describing Intel Thunder Bay Hybrid HDDL Prime
> > +configuration
> > + * board.
> > + *
> > + * DDR 8GB + 4GB with vpu slice 0 and vpu slice 2  */
> > +
> > +/dts-v1/;
> > +
> > +#include "thunderbay-soc.dtsi"
> > +
> > +/ {
> > +	model = "Intel Thunder Bay Hybrid HDDL Prime Board";
> > +	compatible = "intel,thunderbay";
> > +
> > +	#address-cells = <2>;
> > +	#size-cells = <2>;
> > +
> > +	aliases {
> > +		serial0 = &uart0;
> > +		serial1 = &uart1;
> 
> Why do you have an alias to a disabled node?
Ok. Will remove this. 

> 
> > +	};
> > +
> > +	chosen {
> > +		stdout-path = "serial0:115200n8";
> > +	};
> > +
> > +	memory@100A000000 {
> 
> Lowercase hex on unit-addresses.
Ok.

> 
> > +		device_type = "memory";
> > +		/* 8GB of DDR memory */
> > +		reg = <0x10 0x0A000000 0x2 0x0>;
> > +	};
> > +
> > +	memory@1200000000 {
> > +		device_type = "memory";
> > +		/* 4GB of DDR memory */
> > +		reg = <0x12 0x0 0x1 0x0>;
> > +	};
> > +
> > +};
> > diff --git a/arch/arm64/boot/dts/intel/hddl_hybrid_2s_03.dts
> > b/arch/arm64/boot/dts/intel/hddl_hybrid_2s_03.dts
> > new file mode 100644
> > index 0000000..01a3d4c
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/intel/hddl_hybrid_2s_03.dts
> > @@ -0,0 +1,43 @@
> > +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
> > +/*
> > + * Copyright (c) 2021 Intel Corporation.
> > + *
> > + * Device tree describing Intel Thunder Bay Hybrid HDDL Prime
> > +configuration
> > + * board
> > + *
> > + * DDR 8GB + 4GB with vpu slice 0 and vpu slice 3  */
> > +
> > +/dts-v1/;
> > +
> > +#include "thunderbay-soc.dtsi"
> > +
> > +/ {
> > +	model = "Intel Thunder Bay Hybrid HDDL Prime Board";
> > +	compatible = "intel,thunderbay";
> 
> This should have a board specific compatible. Not sure if you need 1 or
> 4 though. If the VPU slice stuff is determined elsewhere then 1 is enough.
Since minimum dts will boot for both 4 slice VPU SoC and 2 slice VPU SoC, I will start with single compatible string now. 
Also minimum dts for 2 VPU slices are same, I will submit common single dts for 2 VPU slice boards in next version.

> 
> > +
> > +	#address-cells = <2>;
> > +	#size-cells = <2>;
> > +
> > +	aliases {
> > +		serial0 = &uart0;
> > +		serial1 = &uart1;
> > +	};
> > +
> > +	chosen {
> > +		stdout-path = "serial0:115200n8";
> > +	};
> > +
> > +	memory@100A000000 {
> > +		device_type = "memory";
> > +		/* 8GB of DDR memory */
> > +		reg = <0x10 0x0A000000 0x2 0x0>;
> > +	};
> > +
> > +	memory@1200000000 {
> > +		device_type = "memory";
> > +		/* 4GB of DDR memory */
> > +		reg = <0x12 0x0 0x1 0x0>;
> > +	};
> > +
> > +};
> > diff --git a/arch/arm64/boot/dts/intel/hddl_hybrid_2s_12.dts
> > b/arch/arm64/boot/dts/intel/hddl_hybrid_2s_12.dts
> > new file mode 100644
> > index 0000000..e31db16
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/intel/hddl_hybrid_2s_12.dts
> > @@ -0,0 +1,43 @@
> > +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
> > +/*
> > + * Copyright (c) 2021 Intel Corporation.
> > + *
> > + * Device tree describing Intel Thunder Bay Hybrid HDDL Prime
> > +configuration
> > + * board
> > + *
> > + * DDR 8GB + 4GB with vpu slice 1 and vpu slice 2  */
> > +
> > +/dts-v1/;
> > +
> > +#include "thunderbay-soc.dtsi"
> > +
> > +/ {
> > +	model = "Intel Thunder Bay Hybrid HDDL Prime Board";
> > +	compatible = "intel,thunderbay";
> > +
> > +	#address-cells = <2>;
> > +	#size-cells = <2>;
> > +
> > +	aliases {
> > +		serial0 = &uart0;
> > +		serial1 = &uart1;
> > +	};
> > +
> > +	chosen {
> > +		stdout-path = "serial0:115200n8";
> > +	};
> > +
> > +	memory@100A000000 {
> > +		device_type = "memory";
> > +		/* 8GB of DDR memory */
> > +		reg = <0x10 0x0A000000 0x2 0x0>;
> > +	};
> > +
> > +	memory@1200000000 {
> > +		device_type = "memory";
> > +		/* 4GB of DDR memory */
> > +		reg = <0x12 0x0 0x1 0x0>;
> > +	};
> > +
> > +};
> > diff --git a/arch/arm64/boot/dts/intel/hddl_hybrid_2s_13.dts
> > b/arch/arm64/boot/dts/intel/hddl_hybrid_2s_13.dts
> > new file mode 100644
> > index 0000000..6529664
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/intel/hddl_hybrid_2s_13.dts
> > @@ -0,0 +1,43 @@
> > +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
> > +/*
> > + * Copyright (c) 2021 Intel Corporation.
> > + *
> > + * Device tree describing Intel Thunder Bay Hybrid HDDL Prime
> > +configuration
> > + * board
> > + *
> > + * DDR 8GB + 4GB with vpu slice 1 and vpu slice 3  */
> > +
> > +/dts-v1/;
> > +
> > +#include "thunderbay-soc.dtsi"
> > +
> > +/ {
> > +	model = "Intel Thunder Bay Hybrid HDDL Prime Board";
> > +	compatible = "intel,thunderbay";
> > +
> > +	#address-cells = <2>;
> > +	#size-cells = <2>;
> > +
> > +	aliases {
> > +		serial0 = &uart0;
> > +		serial1 = &uart1;
> > +	};
> > +
> > +	chosen {
> > +		stdout-path = "serial0:115200n8";
> > +	};
> > +
> > +	memory@100A000000 {
> > +		device_type = "memory";
> > +		/* 8GB of DDR memory */
> > +		reg = <0x10 0x0A000000 0x2 0x0>;
> > +	};
> > +
> > +	memory@1200000000 {
> > +		device_type = "memory";
> > +		/* 4GB of DDR memory */
> > +		reg = <0x12 0x0 0x1 0x0>;
> > +	};
> > +
> > +};
> 
> These all look the same, why do we need 4 copies?
Full dts will have VPU slice specific dts nodes. Since minimum dts for 2 VPU slices are same, I will submit common single dts for 2 VPU slice boards in next version.

> 
> > diff --git a/arch/arm64/boot/dts/intel/hddl_hybrid_4s.dts
> > b/arch/arm64/boot/dts/intel/hddl_hybrid_4s.dts
> > new file mode 100644
> > index 0000000..561ecea
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/intel/hddl_hybrid_4s.dts
> > @@ -0,0 +1,54 @@
> > +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
> > +/*
> > + * Copyright (c) 2021 Intel Corporation.
> > + *
> > + * Device tree describing Intel Thunder Bay Hybrid HDDL Full
> > +configuration
> > + * board
> > + *
> > + * DDR 8GB + 8GB + 4GB + 4GB with four vpu slices  */
> > +
> > +/dts-v1/;
> > +
> > +#include "thunderbay-soc.dtsi"
> > +
> > +/ {
> > +	model = "Intel Thunder Bay Hybrid HDDL Full Board";
> > +	compatible = "intel,thunderbay";
> > +
> > +	#address-cells = <2>;
> > +	#size-cells = <2>;
> > +
> > +	aliases {
> > +		serial0 = &uart0;
> > +		serial1 = &uart1;
> > +	};
> > +
> > +	chosen {
> > +		stdout-path = "serial0:115200n8";
> > +	};
> > +
> > +	memory@100A000000 {
> > +		device_type = "memory";
> > +		/* 8GB of DDR memory */
> > +		reg = <0x10 0x0A000000 0x2 0x0>;
> > +	};
> > +
> > +	memory@1200000000 {
> > +		device_type = "memory";
> > +		/* 8GB of DDR memory */
> > +		reg = <0x12 0x0 0x2 0x0>;
> > +	};
> > +
> > +	memory@1400000000 {
> > +		device_type = "memory";
> > +		/* 4GB of DDR memory */
> > +		reg = <0x14 0x0 0x1 0x0>;
> > +	};
> > +
> > +	memory@1500000000 {
> > +		device_type = "memory";
> > +		/* 4GB of DDR memory */
> > +		reg = <0x15 0x0 0x1 0x0>;
> > +	};
> > +};
> > diff --git a/arch/arm64/boot/dts/intel/thunderbay-soc.dtsi
> > b/arch/arm64/boot/dts/intel/thunderbay-soc.dtsi
> > new file mode 100644
> > index 0000000..834200d
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/intel/thunderbay-soc.dtsi
> > @@ -0,0 +1,243 @@
> > +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
> > +/*
> > + * Copyright (c) 2021 Intel Corporation.
> > + *
> > + * Device tree describing Thunder Bay SoC  */
> > +
> > +#include <dt-bindings/interrupt-controller/arm-gic.h>
> > +
> > +/ {
> > +
> > +	compatible = "intel,thunderbay";
> > +	#address-cells = <2>;
> > +	#size-cells = <2>;
> > +	interrupt-parent = <&gic>;
> > +
> > +	cpus {
> > +		#address-cells = <2>;
> > +		#size-cells = <0>;
> > +
> > +		cpu-map {
> > +			cluster0 {
> > +				core0 {
> > +					cpu = <&CPU0>;
> > +				};
> > +				core1 {
> > +					cpu = <&CPU1>;
> > +				};
> > +				core2 {
> > +					cpu = <&CPU2>;
> > +				};
> > +				core3 {
> > +					cpu = <&CPU3>;
> > +				};
> > +			};
> > +			cluster1 {
> > +				core0 {
> > +					cpu = <&CPU4>;
> > +				};
> > +				core1 {
> > +					cpu = <&CPU5>;
> > +				};
> > +				core2 {
> > +					cpu = <&CPU6>;
> > +				};
> > +				core3 {
> > +					cpu = <&CPU7>;
> > +				};
> > +			};
> > +			cluster2 {
> > +				core0 {
> > +					cpu = <&CPU8>;
> > +				};
> > +				core1 {
> > +					cpu = <&CPU9>;
> > +				};
> > +				core2 {
> > +					cpu = <&CPU10>;
> > +				};
> > +				core3 {
> > +					cpu = <&CPU11>;
> > +				};
> > +			};
> > +			cluster3 {
> > +				core0 {
> > +					cpu = <&CPU12>;
> > +				};
> > +				core1 {
> > +					cpu = <&CPU13>;
> > +				};
> > +				core2 {
> > +					cpu = <&CPU14>;
> > +				};
> > +				core3 {
> > +					cpu = <&CPU15>;
> > +				};
> > +			};
> > +		};
> > +
> > +		CPU0: cpu@0 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x0>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU1: cpu@1 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x1>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU2: cpu@2 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x2>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU3: cpu@3 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x3>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU4: cpu@100 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x100>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU5: cpu@101 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x101>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU6: cpu@102 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x102>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU7: cpu@103 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x103>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU8: cpu@200 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x200>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU9: cpu@201 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x201>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU10: cpu@202 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x202>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU11: cpu@203 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x203>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU12: cpu@300 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x300>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU13: cpu@301 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x301>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU14: cpu@302 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x302>;
> > +			enable-method = "psci";
> > +		};
> > +
> > +		CPU15: cpu@303 {
> > +			compatible = "arm,cortex-a53";
> > +			device_type = "cpu";
> > +			reg = <0x0 0x303>;
> > +			enable-method = "psci";
> > +		};
> > +	};
> > +
> > +	psci {
> > +		compatible = "arm,psci-0.2";
> 
> PSCI 1.0 has been out for 6 years...
I will update this after verifying our ATF supported PSCI version
 
> 
> > +		method = "smc";
> > +	};
> > +
> > +	gic: interrupt-controller@88400000 {
> > +		compatible = "arm,gic-v3";
> > +		interrupt-controller;
> > +		#interrupt-cells = <3>;
> > +		reg = <0x0 0x88400000 0x0 0x200000>,	/* GICD */
> > +		      <0x0 0x88600000 0x0 0x200000>;	/* GICR */
> > +		/* VGIC maintenance interrupt */
> > +		interrupts = <GIC_PPI 9 IRQ_TYPE_LEVEL_HIGH>;
> > +	};
> > +
> > +	timer {
> > +		compatible = "arm,armv8-timer";
> > +		/* Secure, non-secure, virtual, and hypervisor */
> > +		interrupts = <GIC_PPI 13 IRQ_TYPE_LEVEL_HIGH>,
> > +			     <GIC_PPI 14 IRQ_TYPE_LEVEL_HIGH>,
> > +			     <GIC_PPI 11 IRQ_TYPE_LEVEL_HIGH>,
> > +			     <GIC_PPI 10 IRQ_TYPE_LEVEL_HIGH>;
> > +	};
> > +
> > +	soc {
> > +		compatible = "simple-bus";
> > +		#address-cells = <2>;
> > +		#size-cells = <2>;
> > +		ranges;
> > +		dma-ranges;
> > +
> > +		uart0: serial@80460000 {
> > +			compatible = "snps,dw-apb-uart";
> > +			reg = <0x0 0x80460000 0x0 0x100>;
> > +			interrupts = <GIC_SPI 725 IRQ_TYPE_LEVEL_HIGH>;
> > +			clock-frequency = <50000000>;
> > +			reg-shift = <2>;
> > +			reg-io-width = <4>;
> > +		};
> > +
> > +		uart1: serial@80470000 {
> > +			compatible = "snps,dw-apb-uart";
> > +			reg = <0x0 0x80470000 0x0 0x100>;
> > +			interrupts = <GIC_SPI 724 IRQ_TYPE_LEVEL_HIGH>;
> > +			clock-frequency = <50000000>;
> > +			reg-shift = <2>;
> > +			reg-io-width = <4>;
> > +			status = "disabled";
> > +		};
> > +	};
> > +};
> > --
> > 2.7.4
> >
> >