[经验]

基于Dragonboard 410c的总线控制之UART（二）

2018-9-25 16:39:37

1528 Qualcomm Kernel

   上一篇博客已经介绍了UART在lk里面的配置，接下来看看在kernel中的配置。

   首先是UART的低速模式配置：

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

   aliases {

   uart2 = & blsp1_uart2;          //uart2将会被注册为 ttyHSL2

};

blsp1_uart2: serial@78b0000 {

      compatible = "qcom,msm-lsuart-v14";

      reg = <0x78b0000 0x200>;

      interrupts = <0 108 0>;

      status = "disabled";

      clocks = <&clock_gcc clk_gcc_blsp1_uart2_apps_clk>,

         <&clock_gcc clk_gcc_blsp1_ahb_clk>;

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

};

上面是基础配置，接下来看一下引脚配置

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

      pmx-uartconsole {

         qcom,pins = <&gp 4>, <&gp 5>;

         qcom,num-grp-pins = <2>;

         qcom,pin-func = <2>;

         label = "uart-console";

      uart_console_sleep: uart-console {

            drive-strength = <2>;

            bias-pull-down;

         };

      };

   低速模式配置好了，接下来看一下UART的高速模式配置：

路径：/kerenl/arch/arm/boot/dts/qcom/msm8916.dtsi

aliases {

  uart1 = & blsp1_uart1;

};

blsp1_uart1: uart@78af000 {

      compatible = "qcom,msm-hsuart-v14";

      reg = <0x78af000 0x200>,

            <0x7884000 0x23000>;

      reg-names = "core_mem", "bam_mem";

      interrupt-names = "core_irq", "bam_irq", "wakeup_irq";

      #address-cells = <0>;

      interrupt-parent = <&blsp1_uart1>;

      interrupts = <0 1 2>;

      #interrupt-cells = <1>;

      interrupt-map-mask = <0xffffffff>;

      interrupt-map = <0 &intc 0 107 0

            1 &intc 0 238 0

            2 &msm_gpio 1 0>;

      qcom,bam-tx-ep-pipe-index = <0>;

      qcom,bam-rx-ep-pipe-index = <1>;

      qcom,master-id = <86>;

      clocks = <&clock_gcc clk_gcc_blsp1_uart1_apps_clk>,

         <&clock_gcc clk_gcc_blsp1_ahb_clk>;

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

      qcom,msm-bus,name = "blsp1_uart1";

      qcom,msm-bus,num-cases = <2>;

      qcom,msm-bus,num-paths = <1>;

      qcom,msm-bus,vectors-KBps =

            <86 512 0 0>,

            <86 512 500 800>;

      pinctrl-names = "sleep", "default";

      pinctrl-0 = <&hsuart_sleep>;

      pinctrl-1 = <&hsuart_active>;

      /*status = "disabled";*/

      status = "ok";

};

上面是UART的基础配置，接下来看一下引脚配置：

路径：/kernel/arch/arm/boot/dts/qcom/msm8916-pinc

      blsp1_uart1_active {

         qcom,pins = <&gp 0>, <&gp 1>, <&gp 2>, <&gp 3>;

         qcom,num-grp-pins = <4>;

         qcom,pin-func = <2>;

            label = "blsp1_uart1_active";

         hsuart_active: default {

            drive-strength = <16>;

            bias-disable;

         };

      };

      blsp1_uart1_sleep {

         qcom,pins = <&gp 0>, <&gp 1>, <&gp 2>, <&gp 3>;

         qcom,num-grp-pins = <4>;

         qcom,pin-func = <0>;

            label = "blsp1_uart1_sleep";

         hsuart_sleep: sleep {

            drive-strength = <2>;

            bias-disable;

         };

      };

其他的UART就可以参考这个配置进行配置了。