#include <linux/kernel.h>#include <linux/module.h>#include <linux/miscdevice.h>#include <linux/fs.h>#include <linux/uaccess.h>#include <linux/io.h>#include <linux/irq.h>#include <linux/delay.h>#include <linux/workqueue.h>#include <linux/gpio.h>#include <mach/gpio.h>#include <plat/gpio-cfg.h>#include <linux/timer.h>#include <linux/wait.h>#include <linux/sched.h>#include <linux/poll.h>#include <linux/fcntl.h>#include <linux/interrupt.h>#include <linux/ktime.h>
static unsigned int distance_irq; /*存放中断号*/static u32 *GPB_DAT=NULL;static u32 *GPB_CON=NULL;
static u32 distance_time_us=0; /*表示距离的时间*/
/*工作队列处理函数: */static void distance_work_func(struct work_struct *work){  u32 time1,time2;  time1=ktime_to_us(ktime_get()); /*获取当前时间,再转换为 us 单位*/
  /*等待高电平时间结束*/  while(gpio_get_value(EXYNOS4_GPX1(0))){}    time2=ktime_to_us(ktime_get()); /*获取当前时间,再转换为 us 单位*/
  distance_time_us=time2-time1;  //printk("us=%d\n",time2-time1);   /*us/58=厘米*/}
/*静态方式初始化工作队列*/static DECLARE_WORK(distance_work,distance_work_func);
/*中断处理函数: 用于检测超声波测距的回波*/static irqreturn_t distance_handler(int irq, void *dev){  /*调度工作队列*/  schedule_work(&distance_work);  return IRQ_HANDLED;}
static void distance_function(unsigned long data);/*静态方式定义内核定时器*/static DEFINE_TIMER(distance_timer,distance_function,0,0);
/*内核定时器超时处理函数: 触发超声波发送方波*/static void distance_function(unsigned long data){  static u8 state=0;  state=!state;    /*更改GPIO口电平*/  if(state)  {    *GPB_DAT|=1<<7;  }  else  {    *GPB_DAT&=~(1<<7);  }    /*修改定时器的超时时间*/  mod_timer(&distance_timer,jiffies+msecs_to_jiffies(100));}
static int distance_open(struct inode *inode, struct file *file){  return 0;}
#define GET_US_TIME 0x45612static long distance_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long argv){  u32 *us_data=(u32*)argv;  int err;  u32 time_us=distance_time_us;  switch(cmd)  {    case GET_US_TIME:      err=copy_to_user(us_data,&time_us,4);      if(err!=0)printk("拷贝失败!\n");      break;  }  return 0;}
static int distance_release(struct inode *inode, struct file *file){  return 0;}
/*定义文件操作集合*/static struct file_operations distance_fops={  .open=distance_open,  .unlocked_ioctl=distance_unlocked_ioctl,  .release=distance_release};

/*定义杂项设备结构体*/static struct miscdevice distance_misc={  .minor=MISC_DYNAMIC_MINOR,  .name="tiny4412_distance",  .fops=&distance_fops};
static int __init tiny4412_distance_dev_init(void) {  int err;  /*1. 映射GPIO口地址*/  GPB_DAT=ioremap(0x11400044,4);  GPB_CON=ioremap(0x11400040,4);
  *GPB_CON&=~(0xF<<4*7);  *GPB_CON|=0x1<<4*7; /*配置输出模式*/    /*2. 根据GPIO口编号,获取中断号*/  distance_irq=gpio_to_irq(EXYNOS4_GPX1(0));    /*3. 注册中断*/  err=request_irq(distance_irq,distance_handler,IRQ_TYPE_EDGE_RISING,"distance_device",NULL);  if(err!=0)printk("中断注册失败!\n");  else printk("中断:超声波测距驱动安装成功!\n");
  /*4. 修改定时器超时时间*/  mod_timer(&distance_timer,jiffies+msecs_to_jiffies(100));
  /*杂项设备注册*/  misc_register(&distance_misc);  return 0;}
static void __exit tiny4412_distance_dev_exit(void) {  /*5. 注销中断*/  free_irq(distance_irq,NULL);
  /*6. 停止定时器*/  del_timer(&distance_timer);    /*7. 取消IO映射*/  iounmap(GPB_DAT);  iounmap(GPB_CON);
  /*注销杂项设备*/  misc_deregister(&distance_misc);    printk("中断:超声波测距驱动卸载成功!\n");}
module_init(tiny4412_distance_dev_init);module_exit(tiny4412_distance_dev_exit);MODULE_LICENSE("GPL");MODULE_AUTHOR("tiny4412 wbyq");

#include <stdio.h>#include <linux/fb.h>#include <sys/ioctl.h>
#define PWM_IOCTL_SET_FREQ    1#define PWM_IOCTL_STOP      0
/*主程序*/int main(int argc,char**argv){   int fb;   fb=open("/dev/pwm",2);  if(fb<0)  {     printf("pwm打开失败!\n");     return -1;    }    ioctl(fb,PWM_IOCTL_SET_FREQ,100);  sleep(5);  ioctl(fb,PWM_IOCTL_STOP,0);  return 0;}

#include <stdio.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <sys/ioctl.h>#include <poll.h>#include <signal.h>#include <unistd.h>#include <fcntl.h>#include <poll.h>#include <signal.h>#include <pthread.h>#include <linux/videodev2.h>#include <stdlib.h>#include <sys/mman.h>#include <string.h>#include "framebuffer.h"
#define PWM_DEVICE "/dev/pwm"  /*PWM方波设备文件*/#define DISTANCE_DEVICE "/dev/tiny4412_distance" /*超声波测距设备文件*/#define UVC_VIDEO_DEVICE "/dev/video15"  /*UVC摄像头设备节点*/
#define GET_US_TIME 0x45612     /*获取超声波测量的距离: ioctl命令*/#define PWM_IOCTL_SET_FREQ    1 /*控制PWM方波频率: ioctl命令*/#define PWM_IOCTL_STOP      0 /*停止PWM方波输出: ioctl命令*/
int distance_fd;  /*超声波设备的文件描述符*/int pwm_fd;       /*PWM方波设备的文件描述符*/int uvc_video_fd; /*UVC摄像头设备文件描述符*/int Image_Width;  /*图像的宽度*/int Image_Height; /*图像的高度*/

unsigned char *video_memaddr_buffer[4]; /*存放摄像头映射到进程空间的缓冲区地址*/
/*函数功能: 用户终止了进程调用*/void exit_sighandler(int sig){  //停止PWM波形输出，关闭蜂鸣器  ioctl(pwm_fd,PWM_IOCTL_STOP,0);  close(pwm_fd);  close(distance_fd);  exit(1);}
/*函数功能: 读取超声波数据的线程*/void *distance_Getpthread_func(void *dev){  /*1. 打开PWM方波驱动*/  pwm_fd=open(PWM_DEVICE,O_RDWR);  if(pwm_fd<0) //0 1 2  {    printf("%s 设备文件打开失败\n",PWM_DEVICE);    /*退出线程*/    pthread_exit(NULL);   }
  /*2. 打开超声波测距设备*/  distance_fd=open(DISTANCE_DEVICE,O_RDWR);  if(distance_fd<0) //0 1 2  {    printf("%s 设备文件打开失败\n",DISTANCE_DEVICE);    /*退出线程*/    pthread_exit(NULL);   }
  /*3. 循环读取超声波测量的距离*/  struct pollfd fds;  fds.fd=distance_fd;  fds.events=POLLIN;  int data;  while(1)  {    poll(&fds,1,-1);    ioctl(distance_fd,GET_US_TIME,&data);    printf("距离(cm):%0.2f\n",data/58.0);    data=data/58;    if(data>200) /*200厘米: 安全区域*/    {      //停止PWM波形输出，关闭蜂鸣器      ioctl(pwm_fd,PWM_IOCTL_STOP,0);    }    else if(data>100) /*100厘米: 警告区域*/    {      printf("警告区域!\n");      ioctl(pwm_fd,PWM_IOCTL_SET_FREQ,2);    }    else /*小于<100厘米: 危险区域*/    {      printf(" 危险区域!\n");      ioctl(pwm_fd,PWM_IOCTL_SET_FREQ,10);    }        //ioctl(pwm_fd,PWM_IOCTL_SET_FREQ,pwm_data);    /*倒车影像: 测距有3个档位*/  }}

/*函数功能: UVC摄像头初始化返回值: 0表示成功*/int UVCvideoInit(void){  /*1. 打开摄像头设备*/  uvc_video_fd=open(UVC_VIDEO_DEVICE,O_RDWR);  if(uvc_video_fd<0)  {    printf("%s 摄像头设备打开失败!\n",UVC_VIDEO_DEVICE);    return -1;  }    /*2. 设置摄像头的属性*/  struct v4l2_format format;  memset(&format,0,sizeof(struct v4l2_format));  format.type=V4L2_BUF_TYPE_VIDEO_CAPTURE; /*表示视频捕获设备*/  format.fmt.pix.width=800;  /*预设的宽度*/  format.fmt.pix.height=480; /*预设的高度*/  format.fmt.pix.pixelformat=V4L2_PIX_FMT_YUYV; /*预设的格式*/  format.fmt.pix.field=V4L2_FIELD_ANY; /*系统自动设置: 帧属性*/  if(ioctl(uvc_video_fd,VIDIOC_S_FMT,&format)) /*设置摄像头的属性*/  {    printf("摄像头格式设置失败!\n");    return -2;  }    Image_Width=format.fmt.pix.width;  Image_Height=format.fmt.pix.height;      printf("摄像头实际输出的图像尺寸:x=%d,y=%d\n",format.fmt.pix.width,format.fmt.pix.height);  if(format.fmt.pix.pixelformat==V4L2_PIX_FMT_YUYV)  {    printf("当前摄像头支持YUV格式图像输出!\n");  }  else  {    printf("当前摄像头不支持YUV格式图像输出!\n");    return -3;  }
  /*3. 请求缓冲区: 申请摄像头数据采集的缓冲区*/  struct v4l2_requestbuffers req_buff;  memset(&req_buff,0,sizeof(struct v4l2_requestbuffers));  req_buff.count=4; /*预设要申请4个缓冲区*/  req_buff.type=V4L2_BUF_TYPE_VIDEO_CAPTURE; /*视频捕获设备*/  req_buff.memory=V4L2_MEMORY_MMAP; /*支持mmap内存映射*/  if(ioctl(uvc_video_fd,VIDIOC_REQBUFS,&req_buff)) /*申请缓冲区*/  {    printf("申请摄像头数据采集的缓冲区失败!\n");    return -4;  }  printf("摄像头缓冲区申请的数量: %d\n",req_buff.count);
  /*4. 获取缓冲区的详细信息: 地址,编号*/  struct v4l2_buffer buff_info;  memset(&buff_info,0,sizeof(struct v4l2_buffer));  int i;  for(i=0;i<req_buff.count;i++)  {    buff_info.type=V4L2_BUF_TYPE_VIDEO_CAPTURE; /*视频捕获设备*/    buff_info.memory=V4L2_MEMORY_MMAP; /*支持mmap内存映射*/    if(ioctl(uvc_video_fd,VIDIOC_QUERYBUF,&buff_info)) /*获取缓冲区的详细信息*/    {      printf("获取缓冲区的详细信息失败!\n");      return -5;    }    /*根据摄像头申请缓冲区信息: 使用mmap函数将内核的地址映射到进程空间*/    video_memaddr_buffer[i]=mmap(NULL,buff_info.length,PROT_READ|PROT_WRITE,MAP_SHARED,uvc_video_fd,buff_info.m.offset);     if(video_memaddr_buffer[i]==NULL)    {      printf("缓冲区映射失败!\n");      return -6;    }  }
  /*5. 将缓冲区放入采集队列*/  memset(&buff_info,0,sizeof(struct v4l2_buffer));  for(i=0;i<req_buff.count;i++)  {    buff_info.type=V4L2_BUF_TYPE_VIDEO_CAPTURE; /*视频捕获设备*/    buff_info.index=i; /*缓冲区的节点编号*/    buff_info.memory=V4L2_MEMORY_MMAP; /*支持mmap内存映射*/    if(ioctl(uvc_video_fd,VIDIOC_QBUF,&buff_info)) /*根据节点编号将缓冲区放入队列*/    {      printf("根据节点编号将缓冲区放入队列失败!\n");      return -7;    }  }
  /*6. 启动摄像头数据采集*/  int Type=V4L2_BUF_TYPE_VIDEO_CAPTURE;  if(ioctl(uvc_video_fd,VIDIOC_STREAMON,&Type))  {    printf("启动摄像头数据采集失败!\n");    return -8;  }  return 0;}
/*函数功能: 将YUV数据转为RGB格式函数参数:unsigned char *yuv_buffer: YUV源数据unsigned char *rgb_buffer: 转换之后的RGB数据int iWidth,int iHeight   : 图像的宽度和高度*/void yuv_to_rgb(unsigned char *yuv_buffer,unsigned char *rgb_buffer,int iWidth,int iHeight){  int x;  int z=0;  unsigned char *ptr = rgb_buffer;  unsigned char *yuyv= yuv_buffer;  for (x = 0; x < iWidth*iHeight; x++)   {    int r, g, b;    int y, u, v;
    if (!z)    y = yuyv[0] << 8;    else    y = yuyv[2] << 8;    u = yuyv[1] - 128;    v = yuyv[3] - 128;
    r = (y + (359 * v)) >> 8;    g = (y - (88 * u) - (183 * v)) >> 8;    b = (y + (454 * u)) >> 8;
    *(ptr++) = (r > 255) ? 255 : ((r < 0) ? 0 : r);    *(ptr++) = (g > 255) ? 255 : ((g < 0) ? 0 : g);    *(ptr++) = (b > 255) ? 255 : ((b < 0) ? 0 : b);          if(z++)    {      z = 0;      yuyv += 4;    }  }}
int main(int argc,char **argv){  int data;    /*1. 注册将要捕获的信号*/  signal(SIGINT,exit_sighandler);
  /*2. 创建线程: 采集超声波测量的距离*/  pthread_t threadID;  pthread_create(&threadID,NULL,distance_Getpthread_func,NULL);  pthread_detach(threadID); //设置分离属性
  /*3. 初始化摄像头*/  UVCvideoInit();
  /*4. 初始化LCD屏*/  framebuffer_Device_init();    /*5. 循环采集摄像头的数据*/  struct pollfd fds;  fds.fd=uvc_video_fd;  fds.events=POLLIN;
  struct v4l2_buffer buff_info;  memset(&buff_info,0,sizeof(struct v4l2_buffer));  int index=0; /*表示当前缓冲区的编号*/  unsigned char *rgb_buffer=NULL;
  /*申请空间:存放转换之后的RGB数据*/  rgb_buffer=malloc(Image_Width*Image_Height*3);  if(rgb_buffer==NULL)  {    printf("RGB转换的缓冲区申请失败!\n");    exit(0);  }    while(1)  {    /*1. 等待摄像头采集数据*/    poll(&fds,1,-1); 
    /*2. 取出一帧数据: 从采集队列里面取出一个缓冲区*/    buff_info.type=V4L2_BUF_TYPE_VIDEO_CAPTURE;   /*视频捕获设备*/    ioctl(uvc_video_fd,VIDIOC_DQBUF,&buff_info); /*从采集队列取出缓冲区*/    index=buff_info.index;    //printf("采集数据的缓冲区的编号:%d\n",index);
    /*3. 处理数据: YUV转RGB\显示到LCD屏*/    //video_memaddr_buffer[index]; /*当前存放数据的缓冲区地址*/
    /*3.1 将YUV数据转为RGB格式*/    yuv_to_rgb(video_memaddr_buffer[index],rgb_buffer,Image_Width,Image_Height);
    /*3.2 将RGB数据实时刷新到LCD屏幕上*/    framebuffer_DisplayImages((800-Image_Width)/2,0,Image_Width,Image_Height,rgb_buffer);        /*4. 将缓冲区再次放入采集队列*/    buff_info.memory=V4L2_MEMORY_MMAP;   /*支持mmap内存映射*/    buff_info.type=V4L2_BUF_TYPE_VIDEO_CAPTURE; /*视频捕获设备*/    buff_info.index=index; /*缓冲区的节点编号*/    ioctl(uvc_video_fd,VIDIOC_QBUF,&buff_info); /*根据节点编号将缓冲区放入队列*/  }  return 0;}