在核心裡的配置選項:

make menuconfig ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-
 Device Drivers  --->
    [*] SPI support  --->
        <*>   Allwinner A31 SPI controller  //H5所用的spi控制器驅動

        <*>   User mode SPI device driver support //是一個spi裝置驅動, 用於提供使用者呼叫控制器的介面

spi控制器所用的驅動原始碼在:drivers/spi/spi-sun6i.c

495 static struct platform_driver sun6i_spi_driver = {
496     .probe  = sun6i_spi_probe,
497     .remove = sun6i_spi_remove,
498     .driver = {
499         .name       = "sun6i-spi",
500         .of_match_table = sun6i_spi_match,
501         .pm     = &sun6i_spi_pm_ops,
502     },
503 };

483 static const struct of_device_id sun6i_spi_match[] = {
484
 
     { .compatible = "allwinner,sun6i-a31-spi", .data = (void *)SUN6I_FIFO_DEPTH },
485     { .compatible = "allwinner,sun8i-h3-spi",  .data = (void *)SUN8I_FIFO_DEPTH },
486     {}
487 };

由以上程式碼可見，在裝置樹裡描述spi控制器相關的裝置節點的compatible屬性值應為”allwinner,sun6i-a31-spi”或”allwinner,sun8i-h3-spi”.

H5裡共有兩個spi控制器:

在裝置樹的檔案arch/arm64/boot/dts/allwinner/sunxi-h3-h5.dtsi裡，廠家已寫好兩個spi控制器相關的裝置節點:

445             spi0_pins: spi0 {
446                 pins = "PC0", "PC1", "PC2", "PC3";
447                 function = "spi0";
448             };
449 
450             spi1_pins: spi1 {
451                 pins = "PA15", "PA16", "PA14", "PA13";
452                 function = "spi1";
453             };
    ...

510         spi0: [email protected] {
511             compatible = "allwinner,sun8i-h3-spi";
512             reg = <0x01c68000 0x1000>;
513             interrupts = <GIC_SPI 65 IRQ_TYPE_LEVEL_HIGH>;
514             clocks = <&ccu CLK_BUS_SPI0>, <&ccu CLK_SPI0>;
515             clock-names = "ahb", "mod";
516             dmas = <&dma 23>, <&dma 23>;
517             dma-names = "rx", "tx";
518             pinctrl-names = "default";
519             pinctrl-0 = <&spi0_pins>;
520             resets = <&ccu RST_BUS_SPI0>;
521             status = "disabled";
522             #address-cells = <1>;
523             #size-cells = <0>;
524         };
525 
526         spi1: [email protected] {
527             compatible = "allwinner,sun8i-h3-spi";
528             reg = <0x01c69000 0x1000>;
529             interrupts = <GIC_SPI 66 IRQ_TYPE_LEVEL_HIGH>;
530             clocks = <&ccu CLK_BUS_SPI1>, <&ccu CLK_SPI1>;
531             clock-names = "ahb", "mod";
532             dmas = <&dma 24>, <&dma 24>;
533             dma-names = "rx", "tx";
534             pinctrl-names = "default";
535             pinctrl-0 = <&spi1_pins>;
536             resets = <&ccu RST_BUS_SPI1>;
537             status = "disabled";
538             #address-cells = <1>;
539             #size-cells = <0>;
540         };

在板級主要的裝置樹檔案arch/arm64/boot/dts/allwinner/sun50i-h5-nanopi-neo2.dts:

324 &pio {
    ...
337     spi0_cs_pins: spi0_cs_pins {
338         pins = "PC3", "PA6";
339         function = "gpio_out";
340     };
341 };

414 &spi0 {
415     /* needed to avoid dtc warning */
416     #address-cells = <1>;
417     #size-cells = <0>;
418 
419     status = "okay";
420     pinctrl-names = "default";
421     pinctrl-0 = <&spi0_pins &spi0_cs_pins>;
422     cs-gpios = <&pio 2 3 GPIO_ACTIVE_HIGH>, <&pio 0 6 GPIO_ACTIVE_HIGH>;
    ...

在裝置樹裡廠家已經描述了兩個spi控制器的裝置節點，但在系統裡發生只有spi0控制器是驅動好的:

^_^ / # ls /sys/bus/platform/drivers/sun6i-spi/
1c68000.spi/  bind          uevent        unbind

為了使用擴充套件口上的spi1介面，需要把spi1控制器驅動好:

參考spi0控制器在裝置樹裡的描述, 在sun50i-h5-nanopi-neo2.dts裡增加:
spi1_cs –> PA13

324 &pio {
        ...
341     spi1_cs_pins: spi1_cs_pins {  /* spi1控制器所用的片選線 */
342         pins = "PA13";
343         function = "gpio_out";
344     };
345 };

再增加:
418 &spi1 {
419     #address-cells = <1>;
420     #size-cells = <0>;
421 
422     status = "okay";  /* 此屬性值為"okay"才會裝置使能 */
423     pinctrl-names = "default"; 
424     pinctrl-0 = <&spi1_pins &spi1_cs_pins>; /* spi1控制器所用到的gpio功能配置 */
425     cs-gpios = <&pio 0 13 GPIO_ACTIVE_HIGH>;
426 };

重編裝置樹檔案，更新並啟動系統後:

^_^ / # ls /sys/bus/platform/drivers/sun6i-spi/
1c68000.spi/  1c69000.spi/  bind          uevent        unbind