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

[Martin Botka <martin.botka@somainline.org>]

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 :)
>> 
>>>  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 :)
> 
> 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 :)

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