peripheral-sample/hwtimer_sample.c

/*
 * Copyright (c) 2006-2018, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2018-11-30     misonyo      first implementation.
 */
/*
 * 程序清单：这是一个 hwtimer 设备使用例程
 * 例程导出了 hwtimer_sample 命令到控制终端
 * 命令调用格式：hwtimer_sample
 * 程序功能：硬件定时器周期性的打印当前tick值，2次tick值之差也就是定时时间。
*/

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

#define HWTIMER_DEV_NAME   "timer0"

/* 定时器超时回调函数 */
static rt_err_t timeout_cb(rt_device_t dev, rt_size_t size)
{
    rt_kprintf("this is hwtimer timeout callback fucntion!\n");
    rt_kprintf("tick is :%d !\n", rt_tick_get());

    return 0;
}

static int hwtimer_sample(int argc, char *argv[])
{
    rt_err_t ret = RT_EOK;
    rt_hwtimerval_t timeout_s;
    rt_device_t hw_dev = RT_NULL;
    rt_hwtimer_mode_t mode;         /* 定时器模式 */
    rt_uint32_t freq = 10000;       /* 计数频率 */

    /* 查找定时器设备 */
    hw_dev = rt_device_find(HWTIMER_DEV_NAME);
    if (hw_dev == RT_NULL)
    {
        rt_kprintf("hwtimer sample run failed! can't find %s device!\n", HWTIMER_DEV_NAME);
        return RT_ERROR;
    }

    /* 打开设备 */
    ret = rt_device_open(hw_dev, RT_DEVICE_OFLAG_RDWR);
    if (ret != RT_EOK)
    {
        rt_kprintf("open %s device failed!\n", HWTIMER_DEV_NAME);
        return ret;
    }

    /* 设置超时回调函数 */
    rt_device_set_rx_indicate(hw_dev, timeout_cb);

    /* 设置计数频率(默认1Mhz或支持的最小计数频率) */
    ret = rt_device_control(hw_dev, HWTIMER_CTRL_FREQ_SET, &freq);
    if (ret != RT_EOK)
    {
        rt_kprintf("set frequency failed! ret is :%d\n", ret);
        return ret;
    }

    /* 设置模式为周期性定时器 */
    mode = HWTIMER_MODE_PERIOD;
    ret = rt_device_control(hw_dev, HWTIMER_CTRL_MODE_SET, &mode);
    if (ret != RT_EOK)
    {
        rt_kprintf("set mode failed! ret is :%d\n", ret);
        return ret;
    }

    /* 设置定时器超时值为5s并启动定时器 */
    timeout_s.sec = 5;      /* 秒 */
    timeout_s.usec = 0;     /* 微秒 */

    if (rt_device_write(hw_dev, 0, &timeout_s, sizeof(timeout_s)) != sizeof(timeout_s))
    {
        rt_kprintf("set timeout value failed\n");
        return RT_ERROR;
    }

    /* 延时3500ms */
    rt_thread_mdelay(3500);

    /* 读取定时器当前值 */
    rt_device_read(hw_dev, 0, &timeout_s, sizeof(timeout_s));
    rt_kprintf("Read: Sec = %d, Usec = %d\n", timeout_s.sec, timeout_s.usec);

    return ret;
}
/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(hwtimer_sample, hwtimer sample);