[PATCH 8/9] RISC-V: add litex-linux board support

[Ahmad Fatoum]

Hello Antony,

On 05.05.21 12:08, Antony Pavlov wrote:
> Tested on Digilent Arty FPGA board.
> 
> Signed-off-by: Antony Pavlov <antonynpavlov at gmail.com>
> ---
>  arch/riscv/boards/Makefile               |  1 +
>  arch/riscv/boards/litex-linux/Makefile   |  3 +
>  arch/riscv/boards/litex-linux/lowlevel.c | 20 +++++
>  arch/riscv/dts/Makefile                  |  1 +
>  arch/riscv/dts/litex-linux.dts           | 96 ++++++++++++++++++++++++
>  arch/riscv/mach-litex/Kconfig            |  3 +
>  images/Makefile.riscv                    |  4 +
>  7 files changed, 128 insertions(+)
> 
> diff --git a/arch/riscv/boards/Makefile b/arch/riscv/boards/Makefile
> index 2ce9af41e0..d477cce362 100644
> --- a/arch/riscv/boards/Makefile
> +++ b/arch/riscv/boards/Makefile
> @@ -1,2 +1,3 @@
>  # SPDX-License-Identifier: GPL-2.0
>  obj-$(CONFIG_BOARD_ERIZO_GENERIC)	+= erizo/
> +obj-$(CONFIG_BOARD_LITEX_LINUX)	+= litex-linux/
> diff --git a/arch/riscv/boards/litex-linux/Makefile b/arch/riscv/boards/litex-linux/Makefile
> new file mode 100644
> index 0000000000..3d217ffe0b
> --- /dev/null
> +++ b/arch/riscv/boards/litex-linux/Makefile
> @@ -0,0 +1,3 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +pbl-y += lowlevel.o
> diff --git a/arch/riscv/boards/litex-linux/lowlevel.c b/arch/riscv/boards/litex-linux/lowlevel.c
> new file mode 100644
> index 0000000000..9ac1a3a42e
> --- /dev/null
> +++ b/arch/riscv/boards/litex-linux/lowlevel.c
> @@ -0,0 +1,20 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include <common.h>
> +#include <asm/barebox-riscv.h>
> +#include <debug_ll.h>
> +
> +ENTRY_FUNCTION(start_litex_linux, a0, a1, a2)
> +{
> +	extern char __dtb_z_litex_linux_start[];
> +	extern void __barebox_nmon_entry(void);

I'd suggest <asm/nmon.h>, so this need not be repeated.

> +
> +	if (IS_ENABLED(CONFIG_NMON))
> +		__barebox_nmon_entry();
> +	putc_ll('>');
> +
> +	/* On POR, we are running from read-only memory here. */
> +
> +	barebox_riscv_entry(0x40000000, SZ_256M,
> +			    __dtb_z_litex_linux_start + get_runtime_offset());
> +}
> diff --git a/arch/riscv/dts/Makefile b/arch/riscv/dts/Makefile
> index 4041c34e0c..dc5237b5bb 100644
> --- a/arch/riscv/dts/Makefile
> +++ b/arch/riscv/dts/Makefile
> @@ -5,5 +5,6 @@
>  obj- += dummy.o
>  
>  pbl-$(CONFIG_BOARD_ERIZO_GENERIC) += erizo-generic.dtb.o
> +pbl-$(CONFIG_BOARD_LITEX_LINUX) += litex-linux.dtb.o
>  
>  clean-files := *.dtb *.dtb.S .*.dtc .*.pre .*.dts
> diff --git a/arch/riscv/dts/litex-linux.dts b/arch/riscv/dts/litex-linux.dts
> new file mode 100644
> index 0000000000..aa7e072305
> --- /dev/null
> +++ b/arch/riscv/dts/litex-linux.dts
> @@ -0,0 +1,96 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include "litex_soc_linux.dtsi"
> +
> +#include <dt-bindings/gpio/gpio.h>
> +
> +/ {
> +	model = "LiteX VexRiscV-SoC-Linux";
> +	compatible = "litex,vexriscv-soc-linux";
> +
> +	aliases {
> +		rom = &rom;
> +		sram = &sram;
> +	};
> +
> +	/* ARTY board */
> +	rom: rom at 00000000 {
> +		compatible = "mmio-sram";
> +		reg = <0x00000000 0x00008000>;
> +		read-only;
> +	};
> +
> +	sram: sram at 20000000 {
> +		compatible = "mmio-sram";
> +		reg = <0x20000000 0x00004000>;
> +	};
> +
> +	main_ram: memory at 40000000 {
> +		device_type = "memory";
> +		reg = <0x40000000 0x10000000>;
> +	};
> +};
> +
> +&uart0 {
> +	status = "okay";
> +};
> +
> +&mac0 {
> +	status = "okay";
> +};
> +
> +&spi0 {
> +	status = "okay";
> +
> +	spiflash: w25q128 at 0 {
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +		compatible = "winbond,w25q128", "jedec,spi-nor";
> +		spi-max-frequency = <104000000>;
> +		reg = <0>;
> +	};
> +};
> +
> +/ {

Any reason, this can't be merge into / { } above?

> +	ledsgpio: gpio at f0005000 {
> +		compatible = "ti,74175";
> +		reg = <0xf0005000 0x4>;
> +		gpio-controller;
> +		#gpio-cells = <2>;
> +	};
> +
> +	leds {
> +		compatible = "gpio-leds";
> +
> +		ld0 {

Nitpick: led-0 is what's required by the YAML schema.

> +			label = "arty:green:ld0";
> +			gpios = <&ledsgpio 0 GPIO_ACTIVE_HIGH>;
> +			default-state = "off";

That's redundant, isn't it?

> +		};
> +
> +		ld1 {
> +			label = "arty:green:ld1";
> +			gpios = <&ledsgpio 1 GPIO_ACTIVE_HIGH>;
> +			default-state = "off";
> +		};
> +
> +		ld2 {
> +			label = "arty:green:ld2";
> +			gpios = <&ledsgpio 2 GPIO_ACTIVE_HIGH>;
> +			default-state = "off";
> +		};
> +
> +		ld3 {
> +			label = "arty:green:ld3";
> +			gpios = <&ledsgpio 3 GPIO_ACTIVE_HIGH>;
> +			default-state = "off";
> +		};
> +	};
> +
> +	swgpio: gpio at f0007000 {
> +		compatible = "ti,74125";
> +		reg = <0xf0007000 0x4>;
> +		gpio-controller;
> +		#gpio-cells = <2>;
> +	};
> +};
> diff --git a/arch/riscv/mach-litex/Kconfig b/arch/riscv/mach-litex/Kconfig
> index 19d5927e44..3ff03b0e02 100644
> --- a/arch/riscv/mach-litex/Kconfig
> +++ b/arch/riscv/mach-litex/Kconfig
> @@ -3,6 +3,9 @@ if MACH_LITEX
>  choice
>  	prompt "Board type"
>  
> +config BOARD_LITEX_LINUX
> +	bool "litex linux board"
> +
>  endchoice
>  
>  endif
> diff --git a/images/Makefile.riscv b/images/Makefile.riscv
> index 463c6ce440..831858a54d 100644
> --- a/images/Makefile.riscv
> +++ b/images/Makefile.riscv
> @@ -10,3 +10,7 @@ $(obj)/%.nmon: $(obj)/%.img FORCE
>  pblb-$(CONFIG_BOARD_ERIZO_GENERIC) += start_erizo_generic
>  FILE_barebox-erizo-generic.img = start_erizo_generic.pblb
>  image-$(CONFIG_BOARD_ERIZO_GENERIC) += barebox-erizo-generic.img barebox-erizo-generic.nmon
> +
> +pblb-$(CONFIG_BOARD_LITEX_LINUX) += start_litex_linux
> +FILE_barebox-litex-linux.img = start_litex_linux.pblb
> +image-$(CONFIG_BOARD_LITEX_LINUX) += barebox-litex-linux.img

barebox-litex-linux sounds quite strange for me as someone who hasn't
used LiteX.

> 

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