How to use spi with rpi-4

[Laurentiu-Cristian Duca]

Hi,

I have done it with arch/arm/boot/dts/bcm2835-rpi.dtsi as the following:

/ {
        aliases {
                spi0 = &spi0;
	};

	leds {
		compatible = "gpio-leds";

		act {
			label = "ACT";
			default-state = "keep";
			linux,default-trigger = "heartbeat";
		};
	};

	soc {
                spi0: spi at 7e204000 {
                        /* Add label */
                        dmas = <&dma 6>, <&dma 7>;
                        dma-names = "tx", "rx";
                };

		firmware: firmware {
			compatible = "raspberrypi,bcm2835-firmware", "simple-mfd";
			#address-cells = <1>;
			#size-cells = <1>;

			mboxes = <&mailbox>;
			dma-ranges;
		};

		power: power {
			compatible = "raspberrypi,bcm2835-power";
			firmware = <&firmware>;
			#power-domain-cells = <1>;
		};

		vchiq: mailbox at 7e00b840 {
			compatible = "brcm,bcm2835-vchiq";
			reg = <0x7e00b840 0x3c>;
			interrupts = <0 2>;
		};
	};
};

&gpio {
	pinctrl-names = "default";

        spi0_pins: spi0_pins {
                brcm,pins = <9 10 11>;
                //brcm,function = <4>; /* alt0 */
		brcm,function = <BCM2835_FSEL_ALT0>;
        };

        spi0_cs_pins: spi0_cs_pins {
                brcm,pins = <8 7>;
                brcm,function = <1>; /* output */
        };

	gpioout: gpioout {
		brcm,pins = <6>;
		brcm,function = <BCM2835_FSEL_GPIO_OUT>;
	};

	alt0: alt0 {
		//brcm,pins = <4 5 7 8 9 10 11>;
		brcm,pins = <4 5>;
		brcm,function = <BCM2835_FSEL_ALT0>;
	};

};

&i2c0 {
	pinctrl-names = "default";
	pinctrl-0 = <&i2c0_gpio0>;
	status = "okay";
	clock-frequency = <100000>;
};

&i2c1 {
	pinctrl-names = "default";
	pinctrl-0 = <&i2c1_gpio2>;
	status = "okay";
	clock-frequency = <100000>;
};

&usb {
	power-domains = <&power RPI_POWER_DOMAIN_USB>;
};

&vec {
	power-domains = <&power RPI_POWER_DOMAIN_VEC>;
	status = "okay";
};

&dsi0 {
	power-domains = <&power RPI_POWER_DOMAIN_DSI0>;
};

&dsi1 {
	power-domains = <&power RPI_POWER_DOMAIN_DSI1>;
};

&spi0 {
        pinctrl-names = "default";
        pinctrl-0 = <&spi0_pins &spi0_cs_pins>;
        cs-gpios = <&gpio 8 1>, <&gpio 7 1>;

        /* needed to avoid dtc warning */
        #address-cells = <1>;
        #size-cells = <0>;

        status = "okay";

        spidev0: spidev at 0{
                compatible = "spidev";
                reg = <0>;      // CE0
                #address-cells = <1>;
                #size-cells = <0>;
                spi-max-frequency = <125000000>;
                status = "okay";
        };

        spidev1: spidev at 1{
                compatible = "spidev";
                reg = <1>;      // CE1
                #address-cells = <1>;
                #size-cells = <0>;
                spi-max-frequency = <125000000>;
		status = "okay";
        };
};




On 11/10/20, Laurentiu-Cristian Duca <laurentiu.duca at gmail.com> wrote:
> Dear friends,
>
>    I am trying to test spi on raspberry pi 4.
> I have set dtparam=spi=on in config.txt
>   After I boot the rpi-4, I enter the following commands:
> modprobe spi-bcm2835
> modprobe spi-bcm2835-aux
> modprobe spidev
>   Even so, the /dev/ is not populated with spidev0.0 or spidev0.1 or
> spidev1.0 ...
>
>   I have compiled the dtb with the command:
> make ARCH=arm64 bcm2711-rpi-4-b.dtb
> Also, the kernel is compiled for ARCH=arm64.
>
>   Any ideas on how to have /dev populated?
>
> Thank you very much,
> L-C.
>