Re: [PATCH 3/3] ARM: dts: sunxi: add support for Anbernic RG-Nano

[Andre Przywara <andre.przywara@arm.com>]

On Tue, 20 Jun 2023 15:00:22 -0500
Chris Morgan <macroalpha82@gmail.com> wrote:

Hi Chris,

thanks for sending this!
Is there some schematics for this somewhere? Or was this based on
information gathered from the stock firmware?

> From: Chris Morgan <macromorgan@hotmail.com>
> 
> The Anbernic RG-Nano is a small portable game device based on the
> Allwinner V3s SoC. It has GPIO buttons on the face and side for
> input, a single mono speaker, a 240x240 SPI controlled display,
> and a USB-C OTG port for power. The SoC includes 64MB of RAM and
> an SD card slot for booting.
> 
> The SPI display is currently unsupported, as it will either require
> a new tinydrm driver or changes to the staging fbtft driver to support.
> I plan on working on a tinydrm driver to properly support it. There
> also may be a missing mux in the audio path that must be discovered and
> defined before audio will be fully working (internal speaker does not
> work yet, external headphones untested).
> 
> Working:
> - SDMMC
> - Buttons
> - Charging/battery/PMIC
> 
> Not working:
> - Display
> - Audio
> 
> Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
> ---
>  arch/arm/boot/dts/Makefile                    |   1 +
>  .../boot/dts/sun8i-v3s-anbernic-rg-nano.dts   | 209 ++++++++++++++++++
>  2 files changed, 210 insertions(+)
>  create mode 100644 arch/arm/boot/dts/sun8i-v3s-anbernic-rg-nano.dts
> 
> diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
> index 59829fc90315..31418b594222 100644
> --- a/arch/arm/boot/dts/Makefile
> +++ b/arch/arm/boot/dts/Makefile
> @@ -1414,6 +1414,7 @@ dtb-$(CONFIG_MACH_SUN8I) += \
>  	sun8i-t113s-mangopi-mq-r-t113.dtb \
>  	sun8i-t3-cqa3t-bv3.dtb \
>  	sun8i-v3-sl631-imx179.dtb \
> +	sun8i-v3s-anbernic-rg-nano.dtb \
>  	sun8i-v3s-licheepi-zero.dtb \
>  	sun8i-v3s-licheepi-zero-dock.dtb \
>  	sun8i-v40-bananapi-m2-berry.dtb
> diff --git a/arch/arm/boot/dts/sun8i-v3s-anbernic-rg-nano.dts b/arch/arm/boot/dts/sun8i-v3s-anbernic-rg-nano.dts
> new file mode 100644
> index 000000000000..ead315e8fc38
> --- /dev/null
> +++ b/arch/arm/boot/dts/sun8i-v3s-anbernic-rg-nano.dts
> @@ -0,0 +1,209 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +
> +/dts-v1/;
> +#include <dt-bindings/input/linux-event-codes.h>
> +#include "sun8i-v3s.dtsi"
> +#include "sunxi-common-regulators.dtsi"
> +
> +/ {
> +	model = "Anbernic RG Nano";
> +	compatible = "anbernic,rg-nano", "allwinner,sun8i-v3s";
> +
> +	aliases {
> +		serial0 = &uart0;

Is that serial console actually usable, so are there pins or pads on the
PCB? Have you opened it up?

> +	};
> +
> +	backlight: backlight {
> +		compatible = "pwm-backlight";
> +		pwms = <&pwm 0 40000 1>;
> +		brightness-levels = <0 1 2 3 8 14 21 32 46 60 80 100>;
> +		default-brightness-level = <11>;
> +		power-supply = <&reg_vcc5v0>;
> +	};
> +
> +	chosen {
> +		stdout-path = "serial0:115200n8";
> +	};
> +
> +	gpio_keys: gpio-keys {
> +		compatible = "gpio-keys";
> +
> +		button-a {
> +			gpios = <&gpio_expander 12 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
> +			label = "BTN-A";
> +			linux,code = <BTN_EAST>;
> +		};
> +
> +		button-b {
> +			gpios = <&gpio_expander 14 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
> +			label = "BTN-B";
> +			linux,code = <BTN_SOUTH>;
> +		};
> +
> +		button-down {
> +			gpios = <&gpio_expander 1 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
> +			label = "DPAD-DOWN";
> +			linux,code = <BTN_DPAD_DOWN>;
> +		};
> +
> +		button-left {
> +			gpios = <&gpio_expander 4 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
> +			label = "DPAD-LEFT";
> +			linux,code = <BTN_DPAD_LEFT>;
> +		};
> +
> +		button-right {
> +			gpios = <&gpio_expander 0 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
> +			label = "DPAD-RIGHT";
> +			linux,code = <BTN_DPAD_RIGHT>;
> +		};
> +
> +		button-se {
> +			gpios = <&gpio_expander 7 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
> +			label = "BTN-SELECT";
> +			linux,code = <BTN_SELECT>;
> +		};
> +
> +		button-st {
> +			gpios = <&gpio_expander 6 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
> +			label = "BTN-START";
> +			linux,code = <BTN_START>;
> +		};
> +
> +		button-tl {
> +			gpios = <&gpio_expander 2 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
> +			label = "BTN-L";
> +			linux,code = <BTN_TL>;
> +		};
> +
> +		button-tr {
> +			gpios = <&gpio_expander 15 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
> +			label = "BTN-R";
> +			linux,code = <BTN_TR>;
> +		};
> +
> +		button-up {
> +			gpios = <&gpio_expander 3 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
> +			label = "DPAD-UP";
> +			linux,code = <BTN_DPAD_UP>;
> +		};
> +
> +		button-x {
> +			gpios = <&gpio_expander 11 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
> +			label = "BTN-X";
> +			linux,code = <BTN_NORTH>;
> +		};
> +
> +		button-y {
> +			gpios = <&gpio_expander 13 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
> +			label = "BTN-Y";
> +			linux,code = <BTN_WEST>;
> +		};
> +	};
> +};
> +
> +&codec {
> +	allwinner,audio-routing = "Headphone", "HP",
> +				  "Headphone", "HPCOM",
> +				  "MIC1", "Mic",
> +				  "Mic", "HBIAS";
> +	status = "okay";
> +};
> +
> +&i2c0 {
> +	status = "okay";
> +
> +	gpio_expander: gpio@20 {
> +		compatible = "nxp,pcal6416";
> +		reg = <0x20>;
> +		gpio-controller;
> +		#gpio-cells = <2>;
> +		#interrupt-cells = <2>;
> +		interrupt-controller;
> +		interrupt-parent = <&pio>;
> +		interrupts = <1 3 IRQ_TYPE_EDGE_BOTH>;
> +	};
> +
> +	axp209: pmic@34 {
> +		reg = <0x34>;
> +		interrupt-parent = <&pio>;
> +		interrupts = <1 5 IRQ_TYPE_EDGE_FALLING>;
> +	};
> +
> +	pcf8563: rtc@51 {
> +		compatible = "nxp,pcf8563";
> +		reg = <0x51>;
> +	};
> +};
> +
> +#include "axp209.dtsi"
> +
> +&ac_power_supply {
> +	status = "okay";
> +};
> +
> +&battery_power_supply {
> +	status = "okay";
> +};
> +
> +&mmc0 {
> +	broken-cd;
> +	bus-width = <4>;
> +	disable-wp;
> +	vmmc-supply = <&reg_vcc3v3>;
> +	vqmmc-supply = <&reg_vcc3v3>;
> +	status = "okay";
> +};
> +
> +&pwm {
> +	status = "okay";
> +};
> +
> +&reg_dcdc2 {
> +	regulator-always-on;
> +	regulator-max-microvolt = <1400000>;
> +	regulator-min-microvolt = <1000000>;

I think since it's not referenced anywhere, and it's always-on, it should
be just a single voltage, so the same value for both min and max. I guess
at least this voltage here needs to be fixed anyway, and it wouldn't
really work with a different value? Does the bootloader set something up
there, or is it the default value that's just kept?

> +	regulator-name = "vdd-cpu-sys-ephy";
> +};
> +
> +&reg_dcdc3 {
> +	regulator-always-on;
> +	regulator-max-microvolt = <3450000>;
> +	regulator-min-microvolt = <3000000>;

Same here, I guess: a single voltage.
If in doubt, you could pick the current voltage from
/sys/kernel/debug/regulator/regulator_summary and use that.

> +	regulator-name = "vcc-io-ephy-mcsi-usb";
> +};
> +
> +&reg_ldo1 {
> +	regulator-name = "vcc-rtc";
> +};
> +
> +&reg_ldo2 {
> +	regulator-always-on;
> +	regulator-max-microvolt = <3300000>;
> +	regulator-min-microvolt = <2800000>;

same here.

> +	regulator-name = "avcc-pll";
> +};
> +
> +&spi0 {
> +	status = "okay";
> +};
> +
> +&uart0 {
> +	pinctrl-0 = <&uart0_pb_pins>;
> +	pinctrl-names = "default";
> +	status = "okay";
> +};
> +
> +&usb_otg {
> +	dr_mode = "otg";
> +	status = "okay";
> +};
> +
> +&usb_power_supply {
> +	status = "okay";
> +};
> +
> +&usbphy {
> +	usb0_id_det-gpios = <&pio 5 6 GPIO_ACTIVE_HIGH>;
> +	status = "okay";

So in the commit message you say "USB-C for power", but this here
describes a full featured USB port. So does that work? Can you use it as a
gadget, but also as a host?

Otherwise this looks alright to me.

Cheers,
Andre


> +};