Hi,

On Tue, Jul 14, 2020 at 03:13:05PM +0800, Chen-Yu Tsai wrote:
> From: Chen-Yu Tsai <wens@csie.org>
> 
> The Primo73 is an MSI branded Allwinner A20-based 7-inch tablet. It has
> a metal back case with a plastic insert around where the WiFi antenna is.
> The tablet is (as of July of 2020) no longer available from retailers.
> Kernel sources (as required by GPL) are no longer available from the
> vendor, MSI. The device support page still lists the link, but it is
> dead.
> 
> The tablet features a non-identifiable 1024x600 7" MIPI DPI TFT panel,
> Goodix GT911-based capacitive touchscreen, 1GB DRAM, 8GB MLC NAND,
> RTL8188ETV-based WiFi, an NXP MMA8452 accelerometer for orientation,
> a GC2035 2 megapixel rear camera, a GC0308 0.3 megapixel front camera,
> a mini-HDMI output, a micro-USB port, a headphone jack and single speaker.
> 
> The board design is believe to follow Allwinner's reference design. This
> judgement is based on the fact that the I/O pins and GPIO lines used
> match up with the reference design. Assumptions about the regulator tree
> are based on this.
> 
> The LCD panel only has some serial number markings, and what appears to
> be a part number: "OS1N71J003", which is also a prefix for one of the
> serial number markings. Searching for this part number yielded no
> results. As such, the color depth display timings are directly listed
> in the device tree. The timing are from the FEX file recovered from the
> device. The color depth was derived from the dithering setting from the
> FEX file, as well as independent testing with a color gradient image.
> The internal board, as well as the ribbon cable for the panel, route the
> full 24 bits of color. So the 2 extra bits are dropped either by the
> panel itself or somewhere within the LCD panel module casing.
> 
> Add a device tree for this tablet. Almost the whole device is supported.
> The only things missing are the two cameras, which don't have device
> tree bindings or driver support. The vendor for the LCD panel is left
> out, since there is nothing to go with.
> 
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> ---
> 
> The panel-dpi binding requires a more-specific compatible string.
> However given the vendor of the panel is unknown, I'm not sure what
> the best course of action is here. I opted to put the part number in
> without a vendor prefix.

I guess we could just make up a comptible from the tablet name here?
Something like msi,primo73-panel ?

> ---
>  arch/arm/boot/dts/Makefile              |   1 +
>  arch/arm/boot/dts/sun7i-a20-primo73.dts | 279 ++++++++++++++++++++++++
>  2 files changed, 280 insertions(+)
>  create mode 100644 arch/arm/boot/dts/sun7i-a20-primo73.dts
> 
> diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
> index e6a1cac0bfc7..c09cda958db5 100644
> --- a/arch/arm/boot/dts/Makefile
> +++ b/arch/arm/boot/dts/Makefile
> @@ -1133,6 +1133,7 @@ dtb-$(CONFIG_MACH_SUN7I) += \
>  	sun7i-a20-orangepi-mini.dtb \
>  	sun7i-a20-pcduino3.dtb \
>  	sun7i-a20-pcduino3-nano.dtb \
> +	sun7i-a20-primo73.dtb \
>  	sun7i-a20-wexler-tab7200.dtb \
>  	sun7i-a20-wits-pro-a20-dkt.dtb
>  dtb-$(CONFIG_MACH_SUN8I) += \
> diff --git a/arch/arm/boot/dts/sun7i-a20-primo73.dts b/arch/arm/boot/dts/sun7i-a20-primo73.dts
> new file mode 100644
> index 000000000000..f3b1002ceb50
> --- /dev/null
> +++ b/arch/arm/boot/dts/sun7i-a20-primo73.dts
> @@ -0,0 +1,279 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Copyright (C) 2020 Chen-Yu Tsai <wens@csie.org>
> + */
> +
> +/dts-v1/;
> +#include "sun7i-a20.dtsi"
> +#include "sunxi-common-regulators.dtsi"
> +
> +#include <dt-bindings/gpio/gpio.h>
> +#include <dt-bindings/input/input.h>
> +#include <dt-bindings/interrupt-controller/irq.h>
> +#include <dt-bindings/pwm/pwm.h>
> +
> +/{
> +	model = "MSI Primo73 Tablet";
> +	compatible = "msi,primo73", "allwinner,sun7i-a20";
> +
> +	aliases {
> +		serial0 = &uart0;
> +	};
> +
> +	backlight: backlight {
> +		compatible = "pwm-backlight";
> +		pwms = <&pwm 0 50000 PWM_POLARITY_INVERTED>;
> +		enable-gpios = <&pio 7 7 GPIO_ACTIVE_HIGH>; /* PH7 */
> +	};
> +
> +	chosen {
> +		stdout-path = "serial0:115200n8";
> +	};
> +
> +	hdmi-connector {
> +		compatible = "hdmi-connector";
> +		type = "b";
> +
> +		port {
> +			hdmi_con_in: endpoint {
> +				remote-endpoint = <&hdmi_out_con>;
> +			};
> +		};
> +	};
> +
> +	panel: panel {
> +		compatible = "os1n71j003", "panel-dpi";
> +		backlight = <&backlight>;
> +		power-supply = <&reg_vcc5v0>; /* Actually driven from IPSOUT */
> +		enable-gpios = <&pio 7 8 GPIO_ACTIVE_HIGH>; /* PH8 */
> +		height-mm = <86>;
> +		width-mm = <155>;
> +		bits-per-color = <6>;
> +
> +		panel-timing {
> +			clock-frequency = <60000000>;
> +			hactive = <1024>;
> +			vactive = <600>;
> +			hfront-porch = <160>;
> +			hback-porch = <60>;
> +			hsync-len = <100>;
> +			vback-porch = <13>;
> +			vfront-porch = <10>;
> +			vsync-len = <10>;
> +			de-active = <1>;
> +			pixelclk-active = <0>;
> +		};

The clock frequency doesn't seem to match the rest of the timings
though, it should be around 51MHz. Was this taken from the fex file too?

Maxime