[经验]

基于Dragonboard 410c的总线控制之SPI（二）

2018-9-25 16:39:17

1843 Qualcomm SPI Kernel

   前面一篇已经简单的介绍了SPI的协议，接下来看一下SPI在kernel中的配置。

路径：/kerner/arch/ARM/boot/dts/qcom/msm8916.dtsi

aliases {

      spi0 = &spi_0;

}:

   spi_0: spi@78b9000 { /* BLSP1 QUP3 */

      compatible = "qcom,spi-qup-v2";

            #address-cells = <1>;

            #size-cells = <0>;

            reg-names = "spi_physical", "spi_bam_physical";

            reg = <0x78b9000 0x600>,

                  <0x7884000 0x23000>;

            interrupt-names = "spi_irq", "spi_bam_irq";

            interrupts = <0 99 0>, <0 238 0>;

            spi-max-frequency = <50000000>;

            pinctrl-names = "spi_default", "spi_sleep";

            pinctrl-0 = <&spi2_default &spi2_cs2_active>;

      pinctrl-1 = <&spi2_sleep &spi2_cs2_sleep>;

      clocks = <&clock_gcc clk_gcc_blsp1_ahb_clk>,

         <&clock_gcc clk_gcc_blsp1_qup5_spi_apps_clk>;

      clock-names = "iface_clk", "core_clk";

            qcom,infinite-mode = <0>;

      qcom,use-bam;

      qcom,use-pinctrl;

            qcom,ver-reg-exists;

            qcom,bam-consumer-pipe-index = <12>;

            qcom,bam-producer-pipe-index = <13>;

            qcom,master-id = <86>;

spidev@0 {

      compatible = "spidev";

      spi-max-frequency = <50000000>;

      reg = <0>;

};

      };

最后是引脚配置：

路径：/kernel/arch/arm/boot/dts/qcom/msm8916-pinctrl.dtsi

      spi2_active {

         /* MOSI, MISO, CLK */

         qcom,pins = <&gp 16>, <&gp 17>, <&gp 19>;

         qcom,num-grp-pins = <3>;

         qcom,pin-func = <1>;

         label = "spi2-active";

         /* active state */

         spi2_default: default {

            drive-strength = <12>; /* 12 MA */

            bias-disable = <0>; /* No PULL */

         };

      };

      spi2_cs2_active {

         /* CS */

         qcom,pins = <&gp 18>;

         qcom,num-grp-pins = <1>;

         qcom,pin-func = <1>;

         label = "spi2-cs0-active";

         spi2_cs2_active: cs2_active {

            drive-strength = <2>;

            bias-disable = <0>;

         };

      };

      spi2_suspend {

         /* MOSI, MISO, CLK */

         qcom,pins = <&gp 16>, <&gp 17>, <&gp 19>;

         qcom,num-grp-pins = <3>;

         qcom,pin-func = <0>;

         label = "spi2-suspend";

         /* suspended state */

         spi2_sleep: sleep {

            drive-strength = <2>; /* 2 MA */

            bias-pull-down; /* pull down */

         };

      };

      spi2_cs2_suspend {

         /* CS */

         qcom,pins = <&gp 18>;

         qcom,num-grp-pins = <1>;

         qcom,pin-func = <0>;

         label = "spi2-cs0-suspend";

         spi2_cs2_sleep: cs2_sleep {

            drive-strength = <2>;

            bias-disable = <0>;

         };

      };

到这SPI的kernel配置就可以了。