1. 框架图

2. 设备访问示例

#include <rtthread.h>
#include <rtdevice.h>

#define IWDG_DEVICE_NAME    "wdt"

static rt_device_t wdg_dev;

static void idle_hook(void)
{
    /* 在空闲线程的回调函数里喂狗 */
    rt_device_control(wdg_dev, RT_DEVICE_CTRL_WDT_KEEPALIVE, NULL);
    rt_kprintf("feed the dog!\n ");
}

int main(void)
{
    rt_err_t res = RT_EOK;
    rt_uint32_t timeout = 10;    /* 溢出时间 */

    /* 根据设备名称查找看门狗设备，获取设备句柄 */
    wdg_dev = rt_device_find(IWDG_DEVICE_NAME);
    if (!wdg_dev)
    {
        rt_kprintf("find %s failed!\n", IWDG_DEVICE_NAME);
        return RT_ERROR;
    }
    /* 初始化设备 */
    res = rt_device_init(wdg_dev);
    if (res != RT_EOK)
    {
        rt_kprintf("initialize %s failed!\n", IWDG_DEVICE_NAME);
        return res;
    }
    /* 设置看门狗溢出时间 */
    res = rt_device_control(wdg_dev, RT_DEVICE_CTRL_WDT_SET_TIMEOUT, &timeout);
    if (res != RT_EOK)
    {
        rt_kprintf("set %s timeout failed!\n", IWDG_DEVICE_NAME);
        return res;
    }
    /* 设置空闲线程回调函数 */
    rt_thread_idle_sethook(idle_hook);

    return res;
}

3. 注意

新增 BSP 设备驱动到 I/O 设备模型框架上时，开发者只需开发驱动层即可，设备驱动框架层和 I/O 设备管理层 RT-Thread 已写好了，无需改动，除非发现BUG或增加新的类别。