topic Re: ST7789v In imx8mm in i.MX Processors

ST7789v In imx8mm

Udhay_ — Thu, 11 Jan 2024 14:27:07 GMT

Hello,

we are interfacing SPI communication in st7789v.

&ecspi2 {
#address-cells = <1>;
#size-cells = <0>;
fsl,spi-num-chipselects = <1>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_ecspi2 &pinctrl_ecspi2_cs>;
cs-gpios = <&gpio5 13 GPIO_ACTIVE_LOW>;
status = "okay";

spidev0: spi@0 {
reg = <0>;
compatible = "sitronix,st7789v";
spi-max-frequency = <500000>;
};
}; This is my node

but im getting no data/signal

can anyone please tell me how to interface spi in imx8mm

Regards,

Udhayamoorthi Ramasamy

Re: ST7789v In imx8mm

Manuel_Salas — Fri, 12 Jan 2024 19:31:28 GMT

Hello @Udhay_

I hope you are doing well.

An example of ECSPI implementation on i.MX8MM can be found here:

https://github.com/boundarydevices/linux/blob/boundary-imx_4.14.x_1.0.0_ga/arch/arm64/boot/dts/freescale/imx8mm-nitrogen8mm.dts

If you are using the IMX8MM as slave, we have an application note (AN13633).

I hope this can helps to you.

Best regards.

Salas.

Re: ST7789v In imx8mm

Udhay_ — Wed, 31 Jan 2024 11:31:21 GMT

Hello @Manuel_Salas

I have followed that you have shared me based on that i changed the dtsi node

Here is my node

panel: panel@0{ compatible = "sitronix,st7789v"; reg = <0>; // Chip Select 0 spi-max-frequency = <32000000>; // 32MHz reset-gpios = <&gpio5 26 GPIO_ACTIVE_HIGH>; dc-gpios = <&gpio5 27 GPIO_ACTIVE_HIGH>; spi-cpol; spi-cpha; width = <320>; height = <240>; buswidth = <8>; // Most controllers use this value rotate = <1>; debug = <0x4000000>; // Print init commands to the kernel log }; /* spidev0: spi@0 { reg = <0>; compatible = "rohm,dh2228fv"; spi-max-frequency = <500000>; }; */ };

1. Even if I am not physically connecting the ST7789V to the i.MX8MM, the SPI communication appears to be probed. How can I confirm whether the SPI communication with the ST7789V is indeed happening through the i.MX8MM?

2. Also st7789v_prepare function is not called after st7789v_probe function in panel-sitronix-st7789v.c

Regards,

Udhayamoorthi Ramasamy