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From:   Jernej =?utf-8?B?xaBrcmFiZWM=?= <jernej.skrabec@gmail.com>
To:     Martin Botka <martin.botka@somainline.org>
Cc:     Martin Botka <martin.botka1@gmail.com>,
        Martin Botka <martin@biqu3d.com>,
        Konrad Dybcio <konrad.dybcio@somainline.org>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@somainline.org>,
        Marijn Suijten <marijn.suijten@somainline.org>,
        Jami Kettunen <jamipkettunen@somainline.org>,
        Paul Bouchara <paul.bouchara@somainline.org>,
        Andre Przywara <andre.przywara@arm.com>,
        Martin Botka <martin@biqu3d.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Chen-Yu Tsai <wens@csie.org>,
        Samuel Holland <samuel@sholland.org>,
        Ludwig Kormann <ludwig.kormann@ict42.de>,
        Andrew Lunn <andrew@lunn.ch>, Icenowy Zheng <uwu@icenowy.me>,
        Heiko Stuebner <heiko@sntech.de>,
        Shawn Guo <shawnguo@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Chris Morgan <macromorgan@hotmail.com>,
        Jagan Teki <jagan@edgeble.ai>,
        Maxime Ripard <mripard@kernel.org>, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 4/4] arm64: dts: allwinner: h616: Add BigTreeTech Pi support
Date:   Tue, 05 Sep 2023 22:45:27 +0200
Message-ID: <1909632.taCxCBeP46@archlinux>
In-Reply-To: <KSXWZR.LZT0IYKM7IPF@somainline.org>
References: <20230807145349.2220490-1-martin@biqu3d.com>
 <ZBNDZR.IENEPBA0KL4D2@somainline.org> <KSXWZR.LZT0IYKM7IPF@somainline.org>
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On Thursday, August 24, 2023 10:48:20 PM CEST Martin Botka wrote:
> On Mon, Aug 14 2023 at 12:47:59 PM +02:00:00, Martin Botka
>=20
> <martin.botka@somainline.org> wrote:
> > On Mon, Aug 14 2023 at 12:26:07 PM +02:00:00, Jernej =C5=A0krabec
> >=20
> > <jernej.skrabec@gmail.com> wrote:
> >> Dne nedelja, 13. avgust 2023 ob 18:22:49 CEST je Martin Botka
> >>=20
> >> =7Fnapisal(a):
> >>>  On Sun, Aug 13 2023 at 05:55:35 PM +02:00:00, Jernej =C5=A0krabec
> >>> =20
> >>>  <jernej.skrabec@gmail.com> wrote:
> >>>  > Dne ponedeljek, 07. avgust 2023 ob 16:53:24 CEST je Martin Botka
> >>>  >=20
> >>>  > napisal(a):
> >>>  >>  The BigTreeTech Pi is an H616 based board based on CB1.
> >>>  >>  Just in Rpi format board.
> >>>  >> =20
> >>>  >>  It features the same internals as BTT CB1 but adds:
> >>>  >>      - Fan port
> >>>  >>      - IR receiver
> >>>  >>      - ADXL345 Accelerometer connector via SPI
> >>>  >>      - 24V DC power supply via terminal plugs
> >>>  >>      - USB to CAN module connector (The actual USB to CAN
> >>>=20
> >>> =7F=7Fhappens on
> >>>=20
> >>>  >> the
> >>>  >>=20
> >>>  >>  external module)
> >>>  >> =20
> >>>  >>  List of currently working things is same as BTT CB1 but also:
> >>>  >>      - IR receiver
> >>>  >>      - ADXL345 connector
> >>>  >> =20
> >>>  >>  Signed-off-by: Martin Botka <martin@biqu3d.com>
> >>>  >>  Reviewed-by: Andre Przywara <andre.przywara@arm.com>
> >>>  >>  ---
> >>>  >> =20
> >>>  >>  Changes in V2:
> >>>  >>      - Add UART alongside aliases and chosen for it
> >>>  >>      - Add model string
> >>>  >>      - Enable IR receiver
> >>>  >>      - Enable SPI0 for ADXL345 connector
> >>>  >> =20
> >>>  >>  Changes in V3:
> >>>  >>      - Add missing semicolons
> >>>  >>      - Add pinctrl for SPI0
> >>>  >>  =20
> >>>  >>   arch/arm64/boot/dts/allwinner/Makefile        |  1 +
> >>>  >>   .../allwinner/sun50i-h616-bigtreetech-pi.dts  | 70
> >>>  >>=20
> >>>  >> +++++++++++++++++++
> >>>  >>=20
> >>>  >>   2 files changed, 71 insertions(+)
> >>>  >>   create mode 100644
> >>>  >> =20
> >>>  >>  arch/arm64/boot/dts/allwinner/sun50i-h616-bigtreetech-pi.dts
> >>>  >> =20
> >>>  >>  diff --git a/arch/arm64/boot/dts/allwinner/Makefile
> >>>  >>  b/arch/arm64/boot/dts/allwinner/Makefile index
> >>>  >>=20
> >>>  >> 7b386428510b..0b6232a7f328
> >>>  >>=20
> >>>  >>  100644
> >>>  >>  --- a/arch/arm64/boot/dts/allwinner/Makefile
> >>>  >>  +++ b/arch/arm64/boot/dts/allwinner/Makefile
> >>>  >>  @@ -39,5 +39,6 @@ dtb-$(CONFIG_ARCH_SUNXI) +=3D
> >>>  >>=20
> >>>  >> sun50i-h6-pine-h64-model-b.dtb
> >>>  >>=20
> >>>  >>  dtb-$(CONFIG_ARCH_SUNXI) +=3D sun50i-h6-tanix-tx6.dtb
> >>>  >> =20
> >>>  >>   dtb-$(CONFIG_ARCH_SUNXI) +=3D sun50i-h6-tanix-tx6-mini.dtb
> >>>  >>   dtb-$(CONFIG_ARCH_SUNXI) +=3D
> >>>=20
> >>> =7F=7Fsun50i-h616-bigtreetech-cb1-manta.dtb
> >>>=20
> >>>  >>  +dtb-$(CONFIG_ARCH_SUNXI) +=3D sun50i-h616-bigtreetech-pi.dtb
> >>>  >> =20
> >>>  >>   dtb-$(CONFIG_ARCH_SUNXI) +=3D sun50i-h616-orangepi-zero2.dtb
> >>>  >>   dtb-$(CONFIG_ARCH_SUNXI) +=3D sun50i-h616-x96-mate.dtb
> >>>  >> =20
> >>>  >>  diff --git
> >>>  >>=20
> >>>  >> a/arch/arm64/boot/dts/allwinner/sun50i-h616-bigtreetech-pi.dts
> >>>  >>=20
> >>>  >>  b/arch/arm64/boot/dts/allwinner/sun50i-h616-bigtreetech-pi.dts
> >>>=20
> >>> =7F=7Fnew
> >>>=20
> >>>  >> file
> >>>  >>=20
> >>>  >>  mode 100644
> >>>  >>  index 000000000000..b0d0386e8f13
> >>>  >>  --- /dev/null
> >>>  >>  +++
> >>>=20
> >>> =7F=7Fb/arch/arm64/boot/dts/allwinner/sun50i-h616-bigtreetech-pi.dts
> >>>=20
> >>>  >>  @@ -0,0 +1,70 @@
> >>>  >>  +// SPDX-License-Identifier: (GPL-2.0+ or MIT)
> >>>  >>  +/*
> >>>  >>  + * Copyright (C) 2023 Martin Botka <martin@biqu3d.com>.
> >>>  >>  + */
> >>>  >>  +
> >>>  >>  +/dts-v1/;
> >>>  >>  +
> >>>  >>  +#include "sun50i-h616-bigtreetech-cb1.dtsi"
> >>>  >>  +
> >>>  >>  +/ {
> >>>  >>  +	model =3D "BigTreeTech Pi";
> >>>  >>  +	compatible =3D "bigtreetech,pi", "allwinner,sun50i-h616";
> >>>  >>  +
> >>>  >>  +	aliases {
> >>>  >>  +		serial0 =3D &uart0;
> >>>  >>  +	};
> >>>  >>  +
> >>>  >>  +	chosen {
> >>>  >>  +		stdout-path =3D "serial0:115200n8";
> >>>  >>  +	};
> >>>  >>  +};
> >>>  >>  +
> >>>  >>  +&ehci0 {
> >>>  >>  +	status =3D "okay";
> >>>  >>  +};
> >>>  >>  +
> >>>  >>  +&ehci1 {
> >>>  >>  +	status =3D "okay";
> >>>  >>  +};
> >>>  >>  +
> >>>  >>  +&ehci2 {
> >>>  >>  +	status =3D "okay";
> >>>  >>  +};
> >>>  >>  +
> >>>  >>  +&ehci3 {
> >>>  >>  +	status =3D "okay";
> >>>  >>  +};
> >>>  >>  +
> >>>  >>  +&ir {
> >>>  >>  +	status =3D "okay";
> >>>  >>  +};
> >>>  >>  +
> >>>  >>  +&ohci0 {
> >>>  >>  +	status =3D "okay";
> >>>  >>  +};
> >>>  >>  +
> >>>  >>  +&ohci1 {
> >>>  >>  +	status =3D "okay";
> >>>  >>  +};
> >>>  >>  +
> >>>  >>  +&ohci2 {
> >>>  >>  +	status =3D "okay";
> >>>  >>  +};
> >>>  >>  +
> >>>  >>  +&ohci3 {
> >>>  >>  +	status =3D "okay";
> >>>  >>  +};
> >>>  >>  +
> >>>  >>  +&spi0 {
> >>>  >>  +	/* SPI connection for onboard connector for ADXL345
> >>>=20
> >>> =7F=7Faccelerometer
> >>>=20
> >>>  > */
> >>>  >=20
> >>>  >>  +	status =3D "okay";
> >>>  >>  +	pinctrl-names =3D "default";
> >>>  >>  +	pinctrl-0 =3D <&spi0_pins>, <&spi0_cs0_pin>;
> >>>  >=20
> >>>  > Driver and compatible for ADXL345 already exists, why don't you
> >>>=20
> >>> =7F=7Fadd
> >>>=20
> >>>  > child node
> >>>  > for it?
> >>>  >=20
> >>>  > Best regards,
> >>>  > Jernej
> >>> =20
> >>>  Ah. So the ADXL345 actually wont be driven by kernel.
> >>=20
> >> DT is hardware description, it's not concerned what is done on
> >> =7Fsoftware side,
> >> either kernel or user space.
> >=20
> > Im aware. But this is not a device that is on the board. Its simply a
> > connector for the device.
> > Like Rpi has connectors for camera module :)

Actually it matters only if this other board is firmly connected with base=
=20
board. If it is not, then SPI node should be dropped and be handled with DT=
=20
overlays.

> >=20
> >>>  The SPI connection is enabled so that klipper (3d printer
> >>>=20
> >>> firmware) =7F=7Fcan
> >>>=20
> >>>  be told to look for ADXL345 at this SPI and use it on its own.
> >>> =20
> >>>  Klipper will initialize and communicate with the ADXL on its own.
> >>=20
> >> What do you mean by firmware? User space app? In this case I suppose
> >> =7Fyou'll use
> >> direct SPI commands from user space? AFAIK that's less and less
> >> =7Fsupported by
> >> kernel (in contrast to I2C).
> >=20
> > Firmware as in 3d printer firmware. Klipper runs on the board (CB1 or
> > BTT Pi) and is indeed an userspace app.
> > And indeed uses direct SPI commands to the device.
> >=20
> > The reason for this is the flexibility.
> > If Klipper read the values from kernel or well from the files the
> > ADXL driver would create
> > then it would be unable to communicate with ADXL that is on toolhead
> > board. Or would have to have
> > direct initialization either way for those. Thus it just controls the
> > ADXL itself :)
> >=20
> > I understand that this may be bit confusing. If there is still
> > something not clear im more then happy to explain in
> > full detail how the userspace and 3D printer communicate :)

As I said, DT doesn't care about implementation. DT is HW description, so=20
either if it's fixed connection (soldered wires), then describe in full,=20
otherwise it's considered addon board and thus non-essential, so it should =
be=20
handled with DT overlays.

Can be CB1 bought separately from 3D printer package and thus used without=
=20
ADXL sensor?

> >=20
> > Cheers,
> > Martin.
>=20
> Hello,
> Jernej any comments on this ?
> I would like to resolve this conversation :)
> We do have a bunch of time before the new cycle but never hurts to get
> it figured out ahead of time :)

Sorry, not enough free time over summer.

Best regards,
Jernej

>=20
> Cheers,
> Martin
>=20
> >> Best regards,
> >> Jernej
> >>=20
> >>>  >>  +};
> >>>  >>  +
> >>>  >>  +&uart0 {
> >>>  >>  +	pinctrl-names =3D "default";
> >>>  >>  +	pinctrl-0 =3D <&uart0_ph_pins>;
> >>>  >>  +	status =3D "okay";
> >>>  >>  +};