mt7620a拓展串口

mt7620a拓展串口

要修改的文件有两个:

mt7620a.dtsi

进入/home/ihid/chaos_calmer/target/linux/ramips/dts/mt7620a.dtsi

pinctrl {

              state_default: pinctrl0 {

                     gpio {

                            ralink,group ="i2c","uartf";

                            ralink,function ="gpio";

                     };

              };

       };

把uartf去掉。

MT7620a.dtsi

进入/home/ihid/chaos_calmer/target/linux/ramips/dts/MT7620a.dtsi

chosen {

              bootargs ="console=ttyS0,57600";

       };

把这个ttyS0，改为ttyS1，因为串口驱动起来后，ttyS0做为了扩展串口。Open串口时选择 ttyS0

uart@500 {

                     compatible ="ralink,mt7620a-uart","ralink,rt2880-uart", "ns16550a";

                     reg = <0x500 0x100>;

                     resets = <&rstctrl12>;

                     reset-names ="uart";

                     interrupt-parent =<&intc>;

                     interrupts = <5>;

                     reg-shift = <2>;   

                     status ="disabled";

status= "disabled";改为:

pinctrl-names = "default";

                     pinctrl-0 = <&uartf_gpio_pins>;

                     status = "ok";

即把status = "disabled";这句注释掉或者删除，加上这句默认串口驱动没有加载。

pcm_i2s_pins: pcm_i2s {

                     pcm_i2s {

                            ralink,group ="uartf";

                            ralink,function ="pcm i2s";

                     };

              };

              uartf_gpio_pins: uartf_gpio {

                     uartf_gpio {

                            ralink,group ="uartf";

                            ralink,function ="gpio uartf";

                     };

这里把ralink，function的值都改为uartf。