Re: [PATCH v4 4/4] arm64: dts: allwinner: h616: Add BigTreeTech Pi support

Jernej Škrabec
2023-09-05T20:45:36Z

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
>
> <martin.botka@somainline.org> wrote:
> > On Mon, Aug 14 2023 at 12:26:07 PM +02:00:00, Jernej Škrabec
> >
> > <jernej.skrabec@gmail.com> wrote:
> >> Dne nedelja, 13. avgust 2023 ob 18:22:49 CEST je Martin Botka
> >>
> >> \x7fnapisal(a):
> >>> On Sun, Aug 13 2023 at 05:55:35 PM +02:00:00, Jernej Škrabec
> >>>
> >>> <jernej.skrabec@gmail.com> wrote:
> >>> > Dne ponedeljek, 07. avgust 2023 ob 16:53:24 CEST je Martin Botka
> >>> >
> >>> > napisal(a):
> >>> >> The BigTreeTech Pi is an H616 based board based on CB1.
> >>> >> Just in Rpi format board.
> >>> >>
> >>> >> 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
> >>>
> >>> \x7f\x7fhappens on
> >>>
> >>> >> the
> >>> >>
> >>> >> external module)
> >>> >>
> >>> >> List of currently working things is same as BTT CB1 but also:
> >>> >> - IR receiver
> >>> >> - ADXL345 connector
> >>> >>
> >>> >> Signed-off-by: Martin Botka <martin@biqu3d.com>
> >>> >> Reviewed-by: Andre Przywara <andre.przywara@arm.com>
> >>> >> ---
> >>> >>
> >>> >> Changes in V2:
> >>> >> - Add UART alongside aliases and chosen for it
> >>> >> - Add model string
> >>> >> - Enable IR receiver
> >>> >> - Enable SPI0 for ADXL345 connector
> >>> >>
> >>> >> Changes in V3:
> >>> >> - Add missing semicolons
> >>> >> - Add pinctrl for SPI0
> >>> >>
> >>> >> arch/arm64/boot/dts/allwinner/Makefile | 1 +
> >>> >> .../allwinner/sun50i-h616-bigtreetech-pi.dts | 70
> >>> >>
> >>> >> +++++++++++++++++++
> >>> >>
> >>> >> 2 files changed, 71 insertions(+)
> >>> >> create mode 100644
> >>> >>
> >>> >> arch/arm64/boot/dts/allwinner/sun50i-h616-bigtreetech-pi.dts
> >>> >>
> >>> >> diff --git a/arch/arm64/boot/dts/allwinner/Makefile
> >>> >> b/arch/arm64/boot/dts/allwinner/Makefile index
> >>> >>
> >>> >> 7b386428510b..0b6232a7f328
> >>> >>
> >>> >> 100644
> >>> >> --- a/arch/arm64/boot/dts/allwinner/Makefile
> >>> >> +++ b/arch/arm64/boot/dts/allwinner/Makefile
> >>> >> @@ -39,5 +39,6 @@ dtb-$(CONFIG_ARCH_SUNXI) +=
> >>> >>
> >>> >> sun50i-h6-pine-h64-model-b.dtb
> >>> >>
> >>> >> dtb-$(CONFIG_ARCH_SUNXI) += sun50i-h6-tanix-tx6.dtb
> >>> >>
> >>> >> dtb-$(CONFIG_ARCH_SUNXI) += sun50i-h6-tanix-tx6-mini.dtb
> >>> >> dtb-$(CONFIG_ARCH_SUNXI) +=
> >>>
> >>> \x7f\x7fsun50i-h616-bigtreetech-cb1-manta.dtb
> >>>
> >>> >> +dtb-$(CONFIG_ARCH_SUNXI) += sun50i-h616-bigtreetech-pi.dtb
> >>> >>
> >>> >> dtb-$(CONFIG_ARCH_SUNXI) += sun50i-h616-orangepi-zero2.dtb
> >>> >> dtb-$(CONFIG_ARCH_SUNXI) += sun50i-h616-x96-mate.dtb
> >>> >>
> >>> >> diff --git
> >>> >>
> >>> >> a/arch/arm64/boot/dts/allwinner/sun50i-h616-bigtreetech-pi.dts
> >>> >>
> >>> >> b/arch/arm64/boot/dts/allwinner/sun50i-h616-bigtreetech-pi.dts
> >>>
> >>> \x7f\x7fnew
> >>>
> >>> >> file
> >>> >>
> >>> >> mode 100644
> >>> >> index 000000000000..b0d0386e8f13
> >>> >> --- /dev/null
> >>> >> +++
> >>>
> >>> \x7f\x7fb/arch/arm64/boot/dts/allwinner/sun50i-h616-bigtreetech-pi.dts
> >>>
> >>> >> @@ -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 = "BigTreeTech Pi";
> >>> >> + compatible = "bigtreetech,pi", "allwinner,sun50i-h616";
> >>> >> +
> >>> >> + aliases {
> >>> >> + serial0 = &uart0;
> >>> >> + };
> >>> >> +
> >>> >> + chosen {
> >>> >> + stdout-path = "serial0:115200n8";
> >>> >> + };
> >>> >> +};
> >>> >> +
> >>> >> +&ehci0 {
> >>> >> + status = "okay";
> >>> >> +};
> >>> >> +
> >>> >> +&ehci1 {
> >>> >> + status = "okay";
> >>> >> +};
> >>> >> +
> >>> >> +&ehci2 {
> >>> >> + status = "okay";
> >>> >> +};
> >>> >> +
> >>> >> +&ehci3 {
> >>> >> + status = "okay";
> >>> >> +};
> >>> >> +
> >>> >> +&ir {
> >>> >> + status = "okay";
> >>> >> +};
> >>> >> +
> >>> >> +&ohci0 {
> >>> >> + status = "okay";
> >>> >> +};
> >>> >> +
> >>> >> +&ohci1 {
> >>> >> + status = "okay";
> >>> >> +};
> >>> >> +
> >>> >> +&ohci2 {
> >>> >> + status = "okay";
> >>> >> +};
> >>> >> +
> >>> >> +&ohci3 {
> >>> >> + status = "okay";
> >>> >> +};
> >>> >> +
> >>> >> +&spi0 {
> >>> >> + /* SPI connection for onboard connector for ADXL345
> >>>
> >>> \x7f\x7faccelerometer
> >>>
> >>> > */
> >>> >
> >>> >> + status = "okay";
> >>> >> + pinctrl-names = "default";
> >>> >> + pinctrl-0 = <&spi0_pins>, <&spi0_cs0_pin>;
> >>> >
> >>> > Driver and compatible for ADXL345 already exists, why don't you
> >>>
> >>> \x7f\x7fadd
> >>>
> >>> > child node
> >>> > for it?
> >>> >
> >>> > Best regards,
> >>> > Jernej
> >>>
> >>> Ah. So the ADXL345 actually wont be driven by kernel.
> >>
> >> DT is hardware description, it's not concerned what is done on
> >> \x7fsoftware side,
> >> either kernel or user space.
> >
> > 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
board. If it is not, then SPI node should be dropped and be handled with DT
overlays.

> >
> >>> The SPI connection is enabled so that klipper (3d printer
> >>>
> >>> firmware) \x7f\x7fcan
> >>>
> >>> be told to look for ADXL345 at this SPI and use it on its own.
> >>>
> >>> Klipper will initialize and communicate with the ADXL on its own.
> >>
> >> What do you mean by firmware? User space app? In this case I suppose
> >> \x7fyou'll use
> >> direct SPI commands from user space? AFAIK that's less and less
> >> \x7fsupported by
> >> kernel (in contrast to I2C).
> >
> > 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.
> >
> > 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 :)
> >
> > 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
either if it's fixed connection (soldered wires), then describe in full,
otherwise it's considered addon board and thus non-essential, so it should be
handled with DT overlays.

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

> >
> > Cheers,
> > Martin.
>
> 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

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