linux 自内核3.x之后引入设备树的概念.而不像2.6时代在arch/arm/mach-s2440.c添加修改设备信息。 (推荐一下宋宝华的《Linux设备驱动开发详解:基于最新的Linux 4.0内核》，奉劝各位正学习嵌入式linux的在校学生也要与时俱进) 我使用的设备是beagleboard X15(芯片am5728) 下面是开启uart,i2c ,spi,can等外设的脚本，仅供参考。配置设备树推荐ti 的工具Pinmux &dra7_pmx_core { //系统自带 gpio_keys_pins_default: gpio_keys_pins_default { pinctrl-single,pins = < DRA7XX_CORE_IOPAD(0x358C, PIN_INPUT_PULLUP | MUX_MODE14) /* cam0_field.gpio4_2 */ >; }; myuart1_pins_default: myuart1_pins_default { pinctrl-single,pins = < DRA7XX_CORE_IOPAD(0x37E0, PIN_INPUT | MUX_MODE0) DRA7XX_CORE_IOPAD(0x37E4, PIN_INPUT | MUX_MODE0) >; }; //系统自带 //Tag : 开启uart10 //0x3570，0x3574为物理地址，MUX_MODE8为引脚映射模式8,这些需要通过ti 的工具Pinmux myuart10_pins_default: myuart10_pins_default { pinctrl-single,pins = < DRA7XX_CORE_IOPAD(0x3570, (PIN_INPUT_PULLUP | MUX_MODE8)) /* vin2a_d2.uart10_rxd */ DRA7XX_CORE_IOPAD(0x3574, (PIN_OUTPUT_PULLUP | MUX_MODE8)) /* vin2a_d3.uart10_txd */ >; }; //Tag : 开启i2c5 i2c5_pins_default:i2c5_pins_default{ pinctrl-single,pins = < DRA7XX_CORE_IOPAD(0x3744, PIN_INPUT_PULLUP | PIN_INPUT_SLEW |MUX_MODE4) // i2c5_sda aa3 DRA7XX_CORE_IOPAD(0x3748, PIN_INPUT_PULLUP |PIN_INPUT_SLEW | MUX_MODE4) // i2c5 scl ab9 >; }; //Tag : can1 dcan1_pins_default: dcan1_pins_default { pinctrl-single,pins = < DRA7XX_CORE_IOPAD(0x37d0, PIN_OUTPUT_PULLUP | MUX_MODE0) // dcan1_tx DRA7XX_CORE_IOPAD(0x37d4, PIN_INPUT_PULLUP | MUX_MODE0) // dcan1_rx >; }; dcan1_pins_sleep: dcan1_pins_sleep { pinctrl-single,pins = < DRA7XX_CORE_IOPAD(0x37d0, MUX_MODE15 | PULL_UP) // dcan1_tx.off DRA7XX_CORE_IOPAD(0x37d4, MUX_MODE15 | PULL_UP) // dcan1_rx.off >; }; }; 重要：配置can通信"default", "sleep", "active"三个模式都要配置。我试过就是直接配置active,结果试了一天,can都无法正常通信。切记 &uart10 { pinctrl-names = "default"; pinctrl-0 = <&myuart10_pins_default>; status = "okay"; }; &i2c5 { status = "okay"; pinctrl-names = "default"; pinctrl-0 = <&i2c5_pins_default>; clock-frequency = <400000>; }; //Tag : 配置 spi， //compatible为匹配驱动 &mcspi3 { pinctrl-names = "default"; status = "okay"; spidev@0{ compatible = "spidev"; spi-max-frequency = <48000000>; reg = <0>; status = "okay"; spi-cpol; spi-cpha; }; }; &mcspi4 { pinctrl-names = "default"; status = "okay"; spidev@0 { compatible = "spidev"; spi-max-frequency = <48000000>; reg = <0>; status = "okay"; spi-cpol; spi-cpha; }; }; //Tag : 配置can通信 &dcan1 { status = "okay"; pinctrl-names = "default", "sleep", "active"; pinctrl-0 = <&dcan1_pins_sleep>; pinctrl-1 = <&dcan1_pins_sleep>; pinctrl-2 = <&dcan1_pins_default>; };