Re: [PATCH] arm64: dts: ti: Add support for Siemens IOT2050 boards

On 18:40-20210209, Jan Kiszka wrote:

On 09.02.21 15:44, Nishanth Menon wrote:

quoted

Jan,

A few quick scan comments below, you might need to post based off
5.12-rc1 once available..

Also, I see a bit of warnings with dtbs_check, which probably needs a
little more digging into (pcie insists to get a device_type property,
etc..)

you could use kernel_patch_verify or https://github.com/nmenon/kernel_patch_verify/blob/master/Dockerbuild.md

it throws up a report like this https://pastebin.ubuntu.com/p/SdkZr432z3/

Ok, will have a look - is that checkpatch on steroids?

It does a bit more than execute checkpatch.. you can see the script 
https://github.com/nmenon/kernel_patch_verify/blob/master/kernel_patch_verify

as well, but depending on files, for example: with dts, it does a
dtbs_check, W=2 build, converts dtb to dts and back to dtb to wiggle out
as many issues that people seem to hit against..

There are other solutions out there (patman etc).. in effect just a
wrapper script around standard kernel based checkers..

quoted

So, many of my comments below are just first pass parse of that log -> I
usually do recommend building with W=2 and dtbs_check (with yamlint etc)
to make sure things are a bit sane. Will be good to have additional
eyes.

On 11:21-20210209, Jan Kiszka wrote:

quoted

From: Jan Kiszka <jan.kiszka@siemens.com>

Add support for two Siemens SIMATIC IOT2050 variants, Basic and
Advanced. They are based on the TI AM6528 and AM6548 SOCs.

Based on original version by Le Jin.

Might be good to add links to the boards as well (if available), for
future reference.

Sure, though stability of links is not under my control. But I could
additionally drop https://github.com/siemens/meta-iot2050 here.

hmm.. Something of a reference for folks may be 5 or 10 years down the
road, as to answer "what is this board"? Upto you though..

[...]

quoted

quoted

diff --git a/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi b/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi
new file mode 100644
index 000000000000..de05937dbb60
--- /dev/null
+++ b/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi

@@ -0,0 +1,649 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) Siemens AG, 2018-2021
+ *

Optional: might be nice to add a oneliner comment for reuse scope..

You mean something like "Common bits for IOT2050 basic and advanced boards"?

Yeah, that'd help.

[...]

quoted

quoted

+	gpio-line-names =
+		"wkup_gpio0-base", "", "", "", "UART0-mode1", "UART0-mode0",
+			"UART0-enable", "UART0-terminate", "", "WIFI-disable",
+		"", "", "", "", "", "", "", "", "", "",
+		"", "A4A5-I2C-mux", "", "", "", "USER-button", "", "", "","IO0",
+		"IO1", "IO2", "", "IO3", "IO17-direction",
+			"A5", "IO16-direction", "IO15-direction",
+			"IO14-direction", "A3",
+		"", "IO18-direction", "A4", "A2", "A1",
+			"A0", "", "", "IO13", "IO11",
+		"IO12", "IO10";

Any chance of intending this consistently?

There is in fact a plan behind this way: I intended every 10 entries, to
ease counting the pins (and that proved to be valuable more than once
already).

AAAh.. interesting.. as long as you find it useful, I am ok with it.. it
was'nt obvious to me the first look..

[...]

quoted

quoted

diff --git a/arch/arm64/boot/dts/ti/k3-am6528-iot2050-basic.dts b/arch/arm64/boot/dts/ti/k3-am6528-iot2050-basic.dts
new file mode 100644
index 000000000000..bb9ab4fdd74e
--- /dev/null
+++ b/arch/arm64/boot/dts/ti/k3-am6528-iot2050-basic.dts

@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) Siemens AG, 2018-2021
+ *
+	cpus {
+		cpu-map {
+			/delete-node/ cluster1;
+		};
+		/delete-node/ cpu@100;
+		/delete-node/ cpu@101;
+	};

Personally, I'd prefer this (handling efuse spins in board files or
even overlays) instead of having to create 100s of dtsi per SoC for
every permutation & combination of TI efused devices and handle these
in board files. I do see examples of similar usage elsewhere in:

$ git grep /delete-node/ arch/arm64/boot/dts/

But, if someone has a different opinion, feel free to pipe up with a
reasonable way to prevent file explosion.

Just a side note to folks (since I got a couple of private poked
on this) -> if we do see a pattern going forward where the efuse
parts have more *upstream* boards coming online, we will consider
spawning off dtsi - but I don't see that yet and I don't really want
to create a explosion of real and imagined unused dtsi combinations
"just because someone might need it". There is always the overlay
option for all the other variants that may or maynot exist.

Jan, on patch itself: I might have missed an unused l2-cache (2nd
cluster) entry.. Might be good to check dtb-> dts and give it a glance
if the right set of nodes are present.

quoted

quoted

diff --git a/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced.dts b/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced.dts
new file mode 100644
index 000000000000..aa1ef081ef22
--- /dev/null
+++ b/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced.dts

@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) Siemens AG, 2018-2021
+ *
+ * Authors:
+ *   Le Jin <le.jin@siemens.com>
+ *   Jan Kiszka <jan.kiszk@siemens.com>
+ */
+
+/dts-v1/;
+
+#include "k3-am65-iot2050-common.dtsi"

[...]

Thanks for the review! Will come up with v2 soon, once all the points
are resolved.

Thanks Jan. Glad to see this moving :)

-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D