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：硬件定时器超时回调函数周期性的打印当前tick值，2次tick值之差换算为时间等同于定时时间值。*/#include <rtthread.h>#include <rtdevice.h>#define HWTIMER_DEV_NAME "timer0" /* 定时器名称 *//* 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; /* 定时器超时值 */ rt_device_t hw_dev = RT_NULL; /* 定时器设备句柄 */ 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; } /* 以读写方式打开设备 */ 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);