Inquiry on ST7789V MIPI-DBI Driver Configuration in NCS 2.9.0

[emmovo]

Dear,

I recently upgraded my project from NCS 2.4.0 to NCS 2.9.0 and encountered an issue with the ST7789V display driver.

Previously, I used SPI0 to interface with the ST7789V display, and the configuration in my device tree worked fine. However, after upgrading to NCS 2.9.0, I noticed that the driver type for ST7789V has changed to MIPI-DBI, and my previous device tree configuration is no longer applicable.

I have reviewed the nRF Connect SDK documentation, but I could not find any clear guidance on how to correctly configure MIPI-DBI for ST7789V in the new version. Below is my previous device tree configuration that worked in NCS 2.4.0:

&spi0 {
	st7789v@0 {
		compatible = "sitronix,st7789v";
		reg = <0x0>;
		cmd-data-gpios = <&gpio0 31 GPIO_ACTIVE_LOW>;
		label = "ST7789V";
		status = "okay";
		spi-max-frequency = <2000000>;
		width = <240>;
		height = <280>;
		x-offset = <0>;
		y-offset = <20>;
		vcom = <0x32>;
		gctrl = <0x35>;
		vrhs = <0x15>;
		mdac = <0x00>;
		gamma = <0x01>;
		colmod = <0x55>;
		lcm = <0x2c>;
		porch-param = [0c 0c 00 33 33];
		cmd2en-param = [5a 69 02 01];
		pwctrl1-param = [a4 a1];
		pvgam-param = [d0 08 0e 09 09 05 31 33 48 17 14 15 31 34];
		nvgam-param = [d0 08 0e 09 09 15 31 33 48 17 14 15 31 34];
		ram-param = [00 f8];
		rgb-param = [cd 08 14];
		vdvs = <0x20>;
		reset-gpios = <&gpio0 28 GPIO_ACTIVE_LOW>;
		supply-gpios = <&gpio0 29 GPIO_ACTIVE_LOW>;
	};

	status = "okay";
	cs-gpios = <&gpio0 30 GPIO_ACTIVE_LOW>;
};

&spi0_default {
	group1 {
		psels = <NRF_PSEL(SPIM_SCK, 0, 3)>, <NRF_PSEL(SPIM_MOSI, 0, 4)>;
	};
};

/ {
	chosen {
		zephyr,display = &{/soc/spi@40003000/st7789v@0/};
	};
};

Could you please advise on:

1. How to correctly configure the device tree for ST7789V using MIPI-DBI in NCS 2.9.0?
2. Are there any specific changes in the SPI or display subsystem that I need to consider?
3. Is there an example or reference documentation available for migrating from the old driver to the new one?

I appreciate your support and look forward to your guidance.

Best regards,

emmovo

[Kazi Afroza Sultana]

Hello,

You can see this documentation (Migration guide to Zephyr v3.7.0) to know how to define MIPI-DBI device. 

#include <zephyr/dt-bindings/mipi_dbi/mipi_dbi.h> should be added in the MIPI_DBI bindings device tree.

/* Legacy GC9X01 display definition */
&spi0 {
    gc9a01: gc9a01@0 {
        status = "okay";
        compatible = "galaxycore,gc9x01x";
        reg = <0>;
        spi-max-frequency = <100000000>;
        cmd-data-gpios = <&gpio0 8 GPIO_ACTIVE_HIGH>;
        reset-gpios = <&gpio0 14 GPIO_ACTIVE_LOW>;
        ...
    };
};

/* New display definition with MIPI DBI device */

#include <zephyr/dt-bindings/mipi_dbi/mipi_dbi.h>

...

mipi_dbi {
    compatible = "zephyr,mipi-dbi-spi";
    dc-gpios = <&gpio0 8 GPIO_ACTIVE_HIGH>;
    reset-gpios = <&gpio0 14 GPIO_ACTIVE_LOW>;
    spi-dev = <&spi0>;
    #address-cells = <1>;
    #size-cells = <0>;

    gc9a01: gc9a01@0 {
        status = "okay";
        compatible = "galaxycore,gc9x01x";
        reg = <0>;
        mipi-max-frequency = <100000000>;
        ...
    };
};

[bjornolsen]

I am having the same issue. I think I am close...

for SDK 2.7 this works perfectly

#include <zephyr/dt-bindings/display/panel.h>

/ {
	chosen {
		zephyr,display = &gs91010;
	};
};


 
&spi3 {
	status = "okay";

	gs91010: gc9x01x@0 {
		compatible = "galaxycore,gc9x01x";
		reg = <0>;
		spi-max-frequency = <100000000>;
		width = <240>;
		height = <240>;
		pixel-format = <PANEL_PIXEL_FORMAT_RGB_565>;
		cmd-data-gpios = <&gpio0 30 GPIO_ACTIVE_HIGH>;	
		reset-gpios = <&gpio0 2 GPIO_ACTIVE_LOW>;
		display-inversion; 
		orientation = "180"; // Set to rotate the display
		// gamma settings can be added if needed
	};

	cs-gpios = <&gpio0 31 GPIO_ACTIVE_LOW>;
};

&spi3_default {
	group1 {
		psels = <NRF_PSEL(SPIM_SCK, 0, 28)>,
				<NRF_PSEL(SPIM_MISO, 0, 4)>,
				<NRF_PSEL(SPIM_MOSI, 0, 29)>;
		nordic,drive-mode = <NRF_DRIVE_H0H1>;
	};
};

Now when switching to SDK 2.9

#include <zephyr/dt-bindings/mipi_dbi/mipi_dbi.h>

/ {
	chosen {
		zephyr,display = &gs91010;
	};
};

mipi_dbi {
    compatible = "zephyr,mipi-dbi-spi";
    dc-gpios = <&gpio0 8 GPIO_ACTIVE_HIGH>;
    reset-gpios = <&gpio0 14 GPIO_ACTIVE_LOW>;
    spi-dev = <&spi0>;
    #address-cells = <1>;
    #size-cells = <0>;

    gc9a01: gc9a01@0 {
        status = "okay";
        compatible = "galaxycore,gc9x01x";
        reg = <0>;
        mipi-max-frequency = <100000000>;
        width = <240>;
		height = <240>;
		pixel-format = <PANEL_PIXEL_FORMAT_RGB_565>;
		cmd-data-gpios = <&gpio0 30 GPIO_ACTIVE_HIGH>;	
		reset-gpios = <&gpio0 2 GPIO_ACTIVE_LOW>;
		display-inversion; 
		orientation = "180"; // Set to rotate the display
    };
};

But I get errors such as
"Node mipi_dbi defined outside of root scope. Only reference nodes and the root node itself are allowed

mipi_dbi/"

"devicetree error: ./nrf52840dk_nrf52840.overlay:23 (column 1): parse error: expected '/' or label reference (&foo)
CMake Error at C:/ncs/v2.9.0/zephyr/cmake/modules/dts.cmake:295 (execute_process):"

I have read the various update guidelines, but that does not help me solve this problem

[Kazi Afroza Sultana]

Hello,

The error shows mipi_dbi is defined out of the root scope. You can try to add this inside the root. 

#include <zephyr/dt-bindings/mipi_dbi/mipi_dbi.h>

/ {
    chosen {
        zephyr,display = &gc9a01;
    };

    mipi_dbi {
        compatible = "zephyr,mipi-dbi-spi";
        dc-gpios = <&gpio0 8 GPIO_ACTIVE_HIGH>;
        reset-gpios = <&gpio0 14 GPIO_ACTIVE_LOW>;
        spi-dev = <&spi0>;
        #address-cells = <1>;
        #size-cells = <0>;

        gc9a01: gc9a01@0 {
            status = "okay";
            compatible = "galaxycore,gc9x01x";
            reg = <0>;
            mipi-max-frequency = <100000000>;
            width = <240>;
            height = <240>;
            pixel-format = <PANEL_PIXEL_FORMAT_RGB_565>;
            display-inversion;
            orientation = "180"; // Set to rotate the display
        };
    };
};

[bjornolsen]

Hi Kazi,

Tried your code.


devicetree error:

nrf52840dk_nrf52840.overlay:37 (column 29): parse error: expected number or parenthesized expression

That is cause by "pixel-format = <PANEL_PIXEL_FORMAT_RGB_565>;"
If I remove that line and recompile


C:/Users/BjornOlsen/Documents/GitHub/nestlab/build/zephyr/include/generated/devicetree_generated.h:15794:50: error: 'DT_N_S_mipi_dbi_S_gc9a01_0_P_width' undeclared here (not in a function); did you mean 'DT_N_S_mipi_dbi_S_gc9a01_0_P_reg'?
15794 | #define DT_CHOSEN_zephyr_display DT_N_S_mipi_dbi_S_gc9a01_0

so now it seems to complain about width.

I feel I am getting closer, but not quite there yet.

[Kazi Afroza Sultana]

Hello,

For the first error, it seems the PANEL_ was not defined. It should be in the devicetree file as header file

#include <zephyr/dt-bindings/display/panel.h>

Can you try this first and see if you get the second error?

[bjornolsen]

Hello.

I get the same error.
But it resolved the issue with pixel-format which I could include.

here is the full overlay.

#include <zephyr/dt-bindings/display/panel.h>
#include <zephyr/dt-bindings/mipi_dbi/mipi_dbi.h>

/ {
    chosen {
        zephyr,display = &gc9a01;
    };

    mipi_dbi {
        compatible = "zephyr,mipi-dbi-spi";
        dc-gpios = <&gpio0 30 GPIO_ACTIVE_HIGH>;
        reset-gpios = <&gpio0 2 GPIO_ACTIVE_LOW>;
        spi-dev = <&spi3>;
        #address-cells = <1>;
        #size-cells = <0>;

        gc9a01: gc9a01@0 {
            status = "okay";
            compatible = "galaxycore,gc9x01x";
            reg = <0>;
            mipi-max-frequency = <100000000>;
            pixel-format = <PANEL_PIXEL_FORMAT_RGB_565>;
            width = <240>;
            height = <240>;
            display-inversion;
            orientation = "180"; // Set to rotate the display
        };
    };
};

&spi3_default {
	group1 {
		psels = <NRF_PSEL(SPIM_SCK, 0, 28)>,
				<NRF_PSEL(SPIM_MISO, 0, 4)>,
				<NRF_PSEL(SPIM_MOSI, 0, 29)>;
		nordic,drive-mode = <NRF_DRIVE_H0H1>;
	};
};

[bjornolsen]

OK I did a completely clean build. now it works 100% all good.

[Kazi Afroza Sultana]

Great! so with these two

#include <zephyr/dt-bindings/display/panel.h>
#include <zephyr/dt-bindings/mipi_dbi/mipi_dbi.h>

header files and the overlay file I attached before solved the issue?

[bjornolsen]

Yes. Thank you