Re: [PATCH 7/7] arm64: dts: exynos: Add initial E850-96 board support

From: Sam Protsenko <semen.protsenko@linaro.org>
To: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Cc: Rob Herring <robh+dt@kernel.org>,
	Sylwester Nawrocki <s.nawrocki@samsung.com>,
	Jaewon Kim <jaewon02.kim@samsung.com>,
	Chanho Park <chanho61.park@samsung.com>,
	David Virag <virag.david003@gmail.com>,
	Youngmin Nam <youngmin.nam@samsung.com>,
	Tomasz Figa <tomasz.figa@gmail.com>,
	Chanwoo Choi <cw00.choi@samsung.com>,
	Michael Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@kernel.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Daniel Palmer <daniel@0x0f.com>, Hao Fang <fanghao11@huawei.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org
Subject: Re: [PATCH 7/7] arm64: dts: exynos: Add initial E850-96 board support
Date: Fri, 17 Dec 2021 02:49:51 +0200	[thread overview]
Message-ID: <CAPLW+4=KLUnNo1xYqqiZqi2+QPi0mKgFmnRk3+1Tw-OS_Bb03w@mail.gmail.com> (raw)
In-Reply-To: <b998809c-9d33-cd42-ebfd-7cce620a6ed8@canonical.com>

On Wed, 15 Dec 2021 at 19:04, Krzysztof Kozlowski
<krzysztof.kozlowski@canonical.com> wrote:
>
> On 15/12/2021 17:09, Sam Protsenko wrote:
> > E850-96 is a 96boards development board manufactured by WinLink. It
> > incorporates Samsung Exynos850 SoC, and is compatible with 96boards
> > mezzanine boards [1], as it follows 96boards standards.
> >
> > This patch adds minimal support for E850-96 board. Next features are
> > enabled in board dts file and verified with minimal BusyBox rootfs:
> >
> >  * User buttons
> >  * LEDs
> >  * Serial console
> >  * Watchdog timers
> >  * RTC
> >  * eMMC
> >
> > [1] https://www.96boards.org/products/mezzanine/
> >
> > Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> > ---
> >  arch/arm64/boot/dts/exynos/Makefile           |   3 +-
> >  .../boot/dts/exynos/exynos850-e850-96.dts     | 157 ++++++++++++++++++
> >  2 files changed, 159 insertions(+), 1 deletion(-)
> >  create mode 100644 arch/arm64/boot/dts/exynos/exynos850-e850-96.dts
> >
> > diff --git a/arch/arm64/boot/dts/exynos/Makefile b/arch/arm64/boot/dts/exynos/Makefile
> > index b41e86df0a84..803548ccc537 100644
> > --- a/arch/arm64/boot/dts/exynos/Makefile
> > +++ b/arch/arm64/boot/dts/exynos/Makefile
> > @@ -3,4 +3,5 @@ dtb-$(CONFIG_ARCH_EXYNOS) += \
> >       exynos5433-tm2.dtb      \
> >       exynos5433-tm2e.dtb     \
> >       exynos7-espresso.dtb    \
> > -     exynosautov9-sadk.dtb
> > +     exynosautov9-sadk.dtb   \
> > +     exynos850-e850-96.dtb
> > diff --git a/arch/arm64/boot/dts/exynos/exynos850-e850-96.dts b/arch/arm64/boot/dts/exynos/exynos850-e850-96.dts
> > new file mode 100644
> > index 000000000000..fd611906d81c
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/exynos/exynos850-e850-96.dts
> > @@ -0,0 +1,157 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * WinLink E850-96 board device tree source
> > + *
> > + * Copyright (C) 2018 Samsung Electronics Co., Ltd.
> > + * Copyright (C) 2021 Linaro Ltd.
> > + *
> > + * Device tree source file for WinLink's E850-96 board which is based on
> > + * Samsung Exynos850 SoC.
> > + */
> > +
> > +/dts-v1/;
> > +
> > +#include "exynos850.dtsi"
> > +#include <dt-bindings/gpio/gpio.h>
> > +#include <dt-bindings/input/input.h>
> > +
> > +#define BOARD_ID     0x0
> > +#define BOARD_REV    0x2
> > +
> > +/ {
> > +     model = "WinLink E850-96 board";
> > +     compatible = "winlink,e850-96", "samsung,exynos850";
> > +     board_id = <BOARD_ID>;
> > +     board_rev = <BOARD_REV>;
> > +
> > +     chosen {
> > +             stdout-path = &serial_0;
> > +     };
> > +
>
> You did not define memory node. Do you expect bootloader to fill it?
> Does it change between different boards?
>

Yeah, bootloader fills it. But now I can see it's probably better to
specify it explicitly specify it in dts. Will do in v2.

>
> Best regards,
> Krzysztof