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

On Wed, 15 Dec 2021 at 19:04, Krzysztof Kozlowski
[off-list ref] wrote:

On 15/12/2021 17:09, Sam Protsenko wrote:

quoted

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