RT-Thread-【英飞凌开发板模块评测任务大挑战】-4-硬件定时器的使用RT-Thread问答社区

【英飞凌开发板模块评测任务大挑战】-4-硬件定时器的使用

发布于 2023-05-04 12:08:11 浏览：306 订阅该版

[tocm]

# 4.硬件定时器的使用和学习

代码托管地址：[RTT_CY8C624ALQALQI: RTT_CY8C624ALQALQI RT_thread联合英飞凌联合开发mcu双核开发板 (gitee.com)](https://gitee.com/chejia12/rtt_-cy8-c624-alqalqi)

这里依然使用mdk的看法环境，使用mdk编译程序，下载程序

## 4.1配置使能硬件定时器2

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230504/efc730fb3469431e0f6726316e6b524b.png)
## 4.2 编写定时器的测试函数

```c
/*
 * 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   "time2"     /* 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;
}

int hwtimer_sample(void)
{
    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(若未设置该项，默认为1Mhz 或 支持的最小计数频率) */
    rt_device_control(hw_dev, HWTIMER_CTRL_FREQ_SET, &freq);
    /* 设置模式为周期性定时器（若未设置，默认是HWTIMER_MODE_ONESHOT）*/
    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);

```

## 4.3测试函数，查看运行结果

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230504/440313dc056d3ded9b05ff3ce4970b7c.png)

## 4.4硬件定时器设备驱动框架学习

使用方法：

### 4.4.1实现定时器的各个操作函数

```c
/*
    1. 定时器 初始化函数
    2. 定时器起始函数
    3. 定时器停止函数
    4. 定时器的计数值获取
    5. 定时器的控制函数
*/
struct rt_hwtimer_ops
{
    void (*init)(struct rt_hwtimer_device *timer, rt_uint32_t state);
    rt_err_t (*start)(struct rt_hwtimer_device *timer, rt_uint32_t cnt, rt_hwtimer_mode_t mode);
    void (*stop)(struct rt_hwtimer_device *timer);
    rt_uint32_t (*count_get)(struct rt_hwtimer_device *timer);
    rt_err_t (*control)(struct rt_hwtimer_device *timer, rt_uint32_t cmd, void *args);
};
```

### 4.4.2配置定时器的基本参数

```c
/* 定时器特征描述 Timer Feature Information */
struct rt_hwtimer_info
{
    rt_int32_t maxfreq;    /* 最大频率 the maximum count frequency timer support */
    rt_int32_t minfreq;    /* 最小频率 the minimum count frequency timer support */
    rt_uint32_t maxcnt;    /* 最大计数 值counter maximum value */
    rt_uint8_t  cntmode;   /* 计数方向 count mode (inc/dec) */
};

typedef struct rt_hwtimer_device
{
    struct rt_device parent;//基本设备驱动框架
    const struct rt_hwtimer_ops *ops;//定时器特有的操作函数
    const struct rt_hwtimer_info *info;//定时器相关的参数信息

rt_int32_t freq;                /* 用户设置的计数频率 counting frequency set by the user */
    rt_int32_t overflow;            /* 定时器溢出 timer overflows */
    float period_sec;
    rt_int32_t cycles;              /* 溢出后将生成超时事件多少次 how many times will generate a timeout event after overflow */
    rt_int32_t reload;              /* 重新加载循环（使用周期模式） reload cycles(using in period mode) */
    rt_hwtimer_mode_t mode;         /* 计时模式（一次/周期） timing mode(oneshot/period) */
} rt_hwtimer_t;
```

### 4.4.3注册定时器的设备到驱动框架

```c
/*
    定时器设备注册函数
*/
rt_err_t rt_device_hwtimer_register(rt_hwtimer_t *timer, const char *name, void *user_data);
```

### 4.4.4详细的定时器设备驱动相关

```c
/*
 * Copyright (c) 2006-2023, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 */
#ifndef __HWTIMER_H__
#define __HWTIMER_H__

#include <rtthread.h>

#ifdef __cplusplus
extern "C" {
#endif

/* 定时器的控制命令类型 */
typedef enum
{
    HWTIMER_CTRL_FREQ_SET = RT_DEVICE_CTRL_BASE(Timer) + 0x01,           /* 设置技术的频率set the count frequency */
    HWTIMER_CTRL_STOP = RT_DEVICE_CTRL_BASE(Timer) + 0x02,               /* 停止定时器stop timer */
    HWTIMER_CTRL_INFO_GET = RT_DEVICE_CTRL_BASE(Timer) + 0x03,           /* 获取计时器功能信息 get a timer feature information */
    HWTIMER_CTRL_MODE_SET = RT_DEVICE_CTRL_BASE(Timer) + 0x04            /* 设置定时器的工作模式 Setting the timing mode(oneshot/period) */
} rt_hwtimer_ctrl_t;

/* Timing Mode */
typedef enum
{
    HWTIMER_MODE_ONESHOT = 0x01,//单次模式
    HWTIMER_MODE_PERIOD//周期模式
} rt_hwtimer_mode_t;

/* Time Value */
typedef struct rt_hwtimerval
{
    rt_int32_t sec;      /* 秒 second */
    rt_int32_t usec;     /* 微秒 microsecond */
} rt_hwtimerval_t;

/*计数的方向*/
#define HWTIMER_CNTMODE_UP      0x01 /* increment count mode */
#define HWTIMER_CNTMODE_DW      0x02 /* decreasing count mode */

struct rt_hwtimer_device;
/*
    1. 定时器 初始化函数
    2. 定时器起始函数
    3. 定时器停止函数
    4. 定时器的计数值获取
    5. 定时器的控制函数
*/
struct rt_hwtimer_ops
{
    void (*init)(struct rt_hwtimer_device *timer, rt_uint32_t state);
    rt_err_t (*start)(struct rt_hwtimer_device *timer, rt_uint32_t cnt, rt_hwtimer_mode_t mode);
    void (*stop)(struct rt_hwtimer_device *timer);
    rt_uint32_t (*count_get)(struct rt_hwtimer_device *timer);
    rt_err_t (*control)(struct rt_hwtimer_device *timer, rt_uint32_t cmd, void *args);
};

/* 定时器特征描述 Timer Feature Information */
struct rt_hwtimer_info
{
    rt_int32_t maxfreq;    /* 最大频率 the maximum count frequency timer support */
    rt_int32_t minfreq;    /* 最小频率 the minimum count frequency timer support */
    rt_uint32_t maxcnt;    /* 最大计数 值counter maximum value */
    rt_uint8_t  cntmode;   /* 计数方向 count mode (inc/dec) */
};

#ifdef __cplusplus
}
#endif

#endif

```