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2.9.0, I noticed that the driver type for ST7789V has changed to MIPI-DBI, and my previous device tree configuration is no longer applicable.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 Nanag,

Please send me the overlay file.

BR
Kazi

[nanangcreacoll]

overlay file:

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

/ {
	chosen {
		zephyr,display = &st7789v;
	};

	leds {
        compatible = "gpio-leds";
        lcd_backlight: lcd_backlight {
            gpios = <&gpio0 11 GPIO_ACTIVE_LOW>;
            label = "LCD Backlight";
        };
    };

    mipi_dbi {
        compatible = "zephyr,mipi-dbi-spi";
        status = "okay";
        reset-gpios = <&gpio0 27 GPIO_ACTIVE_LOW>;
        dc-gpios = <&gpio0 31 GPIO_ACTIVE_HIGH>;
        spi-dev = <&spi0>;
        write-only;
        #address-cells = <1>;
        #size-cells = <0>;

        st7789v: st7789v@0 {
            compatible = "sitronix,st7789v";
            status = "okay";
            reg = <0>;
            mipi-max-frequency = <DT_FREQ_M(8)>;
            mipi-mode = "MIPI_DBI_MODE_SPI_4WIRE";
            width = <240>;
            height = <240>;
            x-offset = <0>;
            y-offset = <0>;
            vcom = <0x19>;
            gctrl = <0x35>;
            vrhs = <0x12>;
            vdvs = <0x20>;
            mdac = <0x00>;
            gamma = <0x01>;
            colmod = <0x05>;
            lcm = <0x2c>;
            porch-param = [0c 0c 00 33 33];
            cmd2en-param = [5a 69 02 01];
            pwctrl1-param = [a4 a1];
            pvgam-param = [D0 04 0D 11 13 2B 3F 54 4C 18 0D 0B 1F 23];
            nvgam-param = [D0 04 0C 11 13 2C 3F 44 51 2F 1F 1F 20 23];
            ram-param = [00 F0];
            rgb-param = [CD 08 14];
        };
    };
};

[Kazi Afroza Sultana]

Hello Nanag,

You need to change the parameters following way

1. mipi-mode:
   The value should be an integer macro, not a string. For 4-wire SPI, use <MIPI_DBI_MODE_SPI_4WIRE>.
   Make sure you include the correct header:
   #include <zephyr/dt-bindings/mipi_dbi/mipi_dbi.h>
2. mipi-max-frequency:
   Use a direct integer value (e.g., <8000000>) instead of DT_FREQ_M(8) unless you have that macro defined.

   This is the overlay file after this change

   #include <zephyr/dt-bindings/display/panel.h>
   #include <zephyr/dt-bindings/mipi_dbi/mipi_dbi.h>
   
   / {
       chosen {
           zephyr,display = &st7789v;
       };
   
       leds {
           compatible = "gpio-leds";
           lcd_backlight: lcd_backlight {
               gpios = <&gpio0 11 GPIO_ACTIVE_LOW>;
               label = "LCD Backlight";
           };
       };
   
       mipi_dbi {
           compatible = "zephyr,mipi-dbi-spi";
           status = "okay";
           reset-gpios = <&gpio0 27 GPIO_ACTIVE_LOW>;
           dc-gpios = <&gpio0 31 GPIO_ACTIVE_HIGH>;
           spi-dev = <&spi0>;
           write-only;
           #address-cells = <1>;
           #size-cells = <0>;
   
           st7789v: st7789v@0 {
               compatible = "sitronix,st7789v";
               status = "okay";
               reg = <0>;
               mipi-max-frequency = <8000000>;
               mipi-mode = <MIPI_DBI_MODE_SPI_4WIRE>;
               width = <240>;
               height = <240>;
               x-offset = <0>;
               y-offset = <0>;
               vcom = <0x19>;
               gctrl = <0x35>;
               vrhs = <0x12>;
               vdvs = <0x20>;
               mdac = <0x00>;
               gamma = <0x01>;
               colmod = <0x05>;
               lcm = <0x2c>;
               porch-param = [0c 0c 00 33 33];
               cmd2en-param = [5a 69 02 01];
               pwctrl1-param = [a4 a1];
               pvgam-param = [D0 04 0D 11 13 2B 3F 54 4C 18 0D 0B 1F 23];
               nvgam-param = [D0 04 0C 11 13 2C 3F 44 51 2F 1F 1F 20 23];
               ram-param = [00 F0];
               rgb-param = [CD 08 14];
           };
       };
   };

   Besides this also can check if your confif file contains following configurations

   CONFIG_SPI=y
   CONFIG_SPI_NRFX=y
   CONFIG_MIPI_DBI=y
   CONFIG_DISPLAY=y
   CONFIG_LVGL=y  # If using LVGL