[devicetree] 设备树运行逻辑

[supperthomas]

研究一下设备树运行逻辑

[supperthomas]

/**
 * @brief Call "fn" on all nodes with compatible DT_DRV_COMPAT
 *        and status "okay"
 *
 * This macro calls "fn(inst)" on each "inst" number that refers to a
 * node with status "okay". Whitespace is added between invocations.
 *
 * Example devicetree fragment:
 *
 *     a {
 *             compatible = "vnd,device";
 *             status = "okay";
 *             label = "DEV_A";
 *     };
 *
 *     b {
 *             compatible = "vnd,device";
 *             status = "okay";
 *             label = "DEV_B";
 *     };
 *
 *     c {
 *             compatible = "vnd,device";
 *             status = "disabled";
 *             label = "DEV_C";
 *     };
* Example usage:
 *
 *     #define DT_DRV_COMPAT vnd_device
 *     #define MY_FN(inst) DT_INST_LABEL(inst),
 *
 *     DT_INST_FOREACH_STATUS_OKAY(MY_FN)
 *
 * This expands to:
 *
 *     MY_FN(0) MY_FN(1)
 *
 * and from there, to either this:
 *
 *     "DEV_A", "DEV_B",
 *
 * or this:
 *
 *     "DEV_B", "DEV_A",
 *
 * No guarantees are made about the order that a and b appear in the
 * expansion.
 *
 * Note that "fn" is responsible for adding commas, semicolons, or
 * other separators or terminators.
 *
 * Device drivers should use this macro whenever possible to
 * instantiate a struct device for each enabled node in the devicetree
 * of the driver's compatible DT_DRV_COMPAT.
 * @param fn Macro to call for each enabled node. Must accept an
 *           instance number as its only parameter.
 */

[supperthomas]

【Zephyr设备树保姆级上手教程【上】】 https://www.bilibili.com/video/BV1q44y1R7hV/?share_source=copy_web&vd_source=26080c5bc3a16e88ddba49dec018a584

[supperthomas]

devicetree 标准 https://github.com/devicetree-org/devicetree-specification

https://github.com/devicetree-org/devicetree-specification/releases/download/v0.4/devicetree-specification-v0.4.pdf

最新的： https://github.com/devicetree-org/devicetree-specification/releases

[supperthomas]

【详解Zephyr设备数与设备驱动模型】 https://www.bilibili.com/video/BV1L94y1F7qS/?share_source=copy_web&vd_source=26080c5bc3a16e88ddba49dec018a584

[supperthomas]

https://docs.zephyrproject.org/latest/build/dts/index.html

[supperthomas]

https://docs.zephyrproject.org/latest/hardware/peripherals/spi.html 一些外设标准接口定义