linux ir驱动学习笔记

ir（infrared remote）红外协议协议主要有REC、RC5/RC6、SONY等。

代码路径：/drivers/media/rc

 

 

keymaps是一些rc_map_table的按键映射，每个遥控器都不一样。

 

ir模块整体框架如下

 

进行设备读取信息操作时，对象是/dev/input/eventX，原因是ir属于input子系统。

 

编译配置

make menuconfig

选择如下，选择编码方式和具体的驱动设备。

 

 

event事件结构如下

struct input_event {  
    struct timeval time;  
    __u16 type;  
    __u16 code;  
    __s32 value;  
};

 

测试代码如下

 

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <linux/rtc.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>
#include <linux/input.h>  

#define DEVICE_NAME "Power Button"

/* get the path of the input device */
int get_event_num(char *path_name)
{
    char dev_name[32];
    char path[32];
    int i, fd;

    for (i = 0; i < 32; i++) {
        sprintf(path, "/dev/input/event%d", i);
        if ((fd = open(path, O_RDONLY, 0)) >= 0) {
            ioctl(fd, EVIOCGNAME(sizeof(dev_name)), dev_name);
            printf("dev_name is %s\n", dev_name);
            printf("path is %s\n", path);
        }
        if (strcmp(dev_name, DEVICE_NAME) == 0) {
            printf("find device\n");
            strcpy(path_name, path);
            break;
        }
    }
    close(fd);

    return 0;
}

/* Get key events of input device */
int keyscan(char *path)
{  
    int ret = -1;
    int i = 0; 
    int key_fd = -1;
    struct input_event key_event  = {0};

    key_fd = open(path, O_RDONLY);
    if(key_fd < 0)
    {  
        printf("---open device error!---\n");
        return -1;
    }
    printf("---open device success!---\n");
    
    while(1)
    {
        ret = lseek(key_fd, 0, SEEK_SET);
        ret = read(key_fd, &key_event, sizeof(key_event));
        
        if(ret) {
            if(key_event.type == EV_KEY  && (key_event.value == 0 || key_event.value == 1)) {
                printf("key %d %s\n", key_event.code, (key_event.value) ? "pressed" : "released");
                if(key_event.code == KEY_ESC)
                    break;
            }
        }
    }
    close(key_fd);
    return ret;
}
 
int main(int arg, char *arc[])  
{
    printf("---This is a key event test!---\n");
    char path[32];
    get_event_num(path);
    keyscan(path);
    printf("---end!---\n");
    
    return 0;
}

 

查看具体的ir设备命令如下

cat /proc/bus/input/devices

安卓命令

dumpsys input

 

 

参考：

https://blog.csdn.net/lanmanck/article/details/8423669

https://blog.csdn.net/piaomiaoju/article/details/35288273

https://blog.csdn.net/cpongo3/article/details/93996024

https://www.cnblogs.com/yangwindsor/articles/3454955.html