topic Re: i.MX8M Plus LPDDR4 EVK Device Tree in i.MX Processors

i.MX8M Plus LPDDR4 EVK Device Tree

Jimmychea — Thu, 12 Jan 2023 03:03:34 GMT

In imx8mp-evk.dts, what is below node for ? Because i can't find the "rohm,dh2228fv" SPI device in schematic.

&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";

    spidev1: spi@0 {
        reg = <0>;
       compatible = "rohm,dh2228fv";
       spi-max-frequency = <500000>;
    };
};

Re: i.MX8M Plus LPDDR4 EVK Device Tree

joanxie — Fri, 13 Jan 2023 03:08:52 GMT

pls refer to the spi driver as below:

"https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/spi/spidev.c?h=lf-5.15.y"

Re: i.MX8M Plus LPDDR4 EVK Device Tree

Jimmychea — Fri, 13 Jan 2023 05:31:04 GMT

Thanks for the information provided. But i want to know does this driver needed ? Because i can't find any dh2228fv hardware component in i.MX8M Plus LPDDR4 EVK schematic.

Re: i.MX8M Plus LPDDR4 EVK Device Tree

joanxie — Fri, 13 Jan 2023 09:20:07 GMT

pls refer to the link as below:

“https://stackoverflow.com/questions/53634892/linux-spidev-why-it-shouldnt-be-directly-in-devicetree#”

spidev is a detail of how Linux controls a device rather than a description of the hardware in the system, any SPI device could be a spidev