SPI

Rockchip 平台拓展引脚 SPI 信息如下：

主板	SOC	平台	拓展引脚
K1	RK3568	Rockchip	SPI X1
K1B	RK3568	Rockchip	SPI X1
K3	RK3562	Rockchip	无
K7	RK3576	Rockchip	SPI X1
K7C	RK3576	Rockchip	SPI X1
K8	RK3588	Rockchip	SPI X2

Allwinner 平台拓展引脚 SPI 信息如下：

主板	SOC	平台	拓展引脚
K2B	H618	Allwinner	SPI X1
K2C	H618	Allwinner	SPI X1
K4B	T113-S3	Allwinner	SPI X1
K5C	A133	Allwinner	SPI X1

DTS 节点配置

Allwinner

Allwinner 平台 spi0 总线配置 dh2228 设备 dts 节点示例：

spi0: spi@05010000 {
    status = "okay";
    dh2228@2 {
        compatible = "rohm,dh2228fv";
        reg = <0>;
        spi-max-frequency = <100000>;
    };
};

Rockchip

Rockchip 平台 spi4 总线配置 spidev 设备 dts 节点示例：

&spi4 {
        pinctrl-names = "default";
        pinctrl-0 = <&spi4_cs0n &spi4m2_pins>;
        status = "okay";

        cs-gpios = <&gpio1 RK_PD0 GPIO_ACTIVE_LOW>;

        spidev0: spidev@0 {
                compatible = "rockchip,spidev";
                status = "okay";
                reg = <0>;
                spi-max-frequency = <24000000>;
        };
};

硬件使用示例

• SPI 引脚

K7 的 SPI 位于引脚8、引脚10、引脚12、引脚16。

• 硬件安装

MISO、MOSI 进行硬件短接，进行回环测试。

spidev_test 测试

• spidev_test 工具安装

下载源码：https://github.com/torvalds/linux/blob/master/tools/spi/spidev_test.c

• 编译 spidev_test

gcc spidev_test.c -o spidev_test
chmod +x spidev_test

• 列出spi设备节点

ls /dev/spi*

• 指定设备进行测试

spidev_test -D /dev/spidev4.0 -v -l -p "hello"

• 测试输出

root@linaro-alip:/# gcc spidev_test.c -o spidev_test
root@linaro-alip:/# chmod +x spidev_test
root@linaro-alip:/# ls /dev/spi*
/dev/spidev4.0
root@linaro-alip:/# ./spidev_test -D /dev/spidev4.0 -v -l -p "hello"
spi mode: 0x20
bits per word: 8
max speed: 500000 Hz (500 kHz)
TX | 68 65 6C 6C 6F __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __  |hello|
RX | 68 65 6C 6C 6F __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __  |hello|
root@linaro-alip:/#