[PATCH v0] arm64: dts: rockchip: add support for ROC-RK3399-PC board

Enric Balletbo Serra [off-list ref] writes:

Hi Levin,

Missatge de Heiko Stuebner [off-list ref] del dia dt., 24 de jul.
2018 a les 11:29:

quoted

Hi Levin,

Am Samstag, 21. Juli 2018, 10:30:26 CEST schrieb djw at t-chip.com.cn:

quoted

From: Levin Du <redacted>

ROC-RK3399-PC is the first power efficient 4GB DDR4 single board

maybe "is a power efficient" instead of "the first" ;-)

[...]

quoted

diff --git a/arch/arm64/boot/dts/rockchip/rk3399-roc-pc.dts b/arch/arm64/boot/dts/rockchip/rk3399-roc-pc.dts
new file mode 100644
index 0000000..207f2e3
--- /dev/null
+++ b/arch/arm64/boot/dts/rockchip/rk3399-roc-pc.dts

@@ -0,0 +1,717 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright (c) 2017 T-Chip Intelligent Technology Co., Ltd
+ */
+
+/dts-v1/;
+#include <dt-bindings/pwm/pwm.h>
+#include "rk3399.dtsi"
+#include "rk3399-opp.dtsi"
+
+/ {
+     model = "Firefly ROC-RK3399-PC Board";
+     compatible = "firefly,roc-rk3399-pc", "rockchip,rk3399";
+
+     chosen {
+             bootargs = "earlycon=uart8250,mmio32,0xff1a0000 swiotlb=1";

I don't think we want to hard-code linux bootargs in the generic devicetree

quoted

+             stdout-path = "serial2:1500000n8";
+     };
+
+     backlight: backlight {
+             compatible = "pwm-backlight";
+             enable-gpios = <&gpio1 RK_PB5 GPIO_ACTIVE_HIGH>;
+             pwms = <&pwm0 0 25000 0>;
+             brightness-levels = <
+                       0   1   2   3   4   5   6   7

As Rob noted in the px30 evb patch, there is now a property helping
to drop these long lists of brightness levels, see
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=1e5e7cc794b5a332c23216dade0a2e937d694b7f

Adding to the Heiko information. Did you try to just remove brightness-levels?
Without this property, the driver computes a default table with the
brightness levels filled with the numbers provided by the CIE 1931
algorithm. That algorithm is used to dim a led for human perception.

Note that the patches needed did not land yet, are in linux-next, and
you will also be interested in apply this patch [1].

[1] https://lkml.org/lkml/2018/7/24/116


Best regards,
 Enric

Thanks you for the note, Enric. I'll test that later.

Regards,
Levin