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

["Jernej Škrabec" <jernej.skrabec@gmail.com>]

Dne nedelja, 13. avgust 2023 ob 18:22:49 CEST je Martin Botka napisal(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 happens 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) += sun50i-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 new
> >> 
> >> file
> >> 
> >>  mode 100644
> >>  index 000000000000..b0d0386e8f13
> >>  --- /dev/null
> >>  +++ b/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 accelerometer
> > 
> > */
> > 
> >>  +	status = "okay";
> >>  +	pinctrl-names = "default";
> >>  +	pinctrl-0 = <&spi0_pins>, <&spi0_cs0_pin>;
> > 
> > Driver and compatible for ADXL345 already exists, why don't you add
> > 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 software side, 
either kernel or user space.

> The SPI connection is enabled so that klipper (3d printer firmware) can
> 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 you'll use 
direct SPI commands from user space? AFAIK that's less and less supported by 
kernel (in contrast to I2C).

Best regards,
Jernej

> 
> >>  +};
> >>  +
> >>  +&uart0 {
> >>  +	pinctrl-names = "default";
> >>  +	pinctrl-0 = <&uart0_ph_pins>;
> >>  +	status = "okay";
> >>  +};