android串口键盘简例

灰太狼 2022-09-17 12:15 325阅读 0赞

这个类似如串口键盘，不过只实现了一些键值，因为这个项目只用到这些。原理：首先开启一个服务循环读取串口的数据，然后将串口读到的数据，写给驱动，驱动在判断是什么键值，然后进行上报。

上层服务源码如下:

#include <stdio.h>
    #include <stdlib.h>
    #include <unistd.h>
    #include <ctype.h>
    #include <sys/socket.h>
    #include <sys/stat.h>
    #include <netinet/ip.h>
    #include <net/if.h>
    #include <sys/types.h>
    #include <sys/ioctl.h>
    #include <linux/rtc.h>
    #include <time.h>
    #include <errno.h>
    #include <termios.h>
    #include <string.h>
    #include <pthread.h>
    #include <fcntl.h>
    #include <sys/mman.h>
    #include <math.h>
    #include <linux/input.h>
    #define LOG_TAG "SerialKey"
    #include <syslog.h>
    
    int main(int argc, char *argv[])
    {
    	int fdosp=-1;
    	int fdc = -1;
    	struct termios option;
    	int status = 0;
    	fdosp=open("/dev/ttyS1",O_RDWR|O_NONBLOCK);
    	if (fdosp<0)
    	{
    		syslog(LOG_ERR,"%s:open devices failed\n",LOG_TAG);
    		return -1;
    	}
    #if 1
    	fdc=open("/dev/gzsd-input",O_RDWR|O_NONBLOCK);
    	if (fdc<0)
    	{
    		syslog(LOG_ERR,"%s:open gzsd-input failed\n",LOG_TAG);
    		return -1;
    	}
    #endif
    	memset(&option, 0, sizeof option);
         	option.c_iflag = IGNPAR;
    	option.c_cflag = B19200 | HUPCL | CS8 | CREAD | CLOCAL;
    	option.c_cc[VMIN] = 2;
    	
    	status = tcsetattr(fdosp, TCSANOW, &option);
    	if (-1 == status)
    	{
    		syslog(LOG_ERR,"%s:set devices failed\n",LOG_TAG);
    		return -1;
    	}
    
    	fd_set readset;
    	struct timeval tv;
    	int MaxFd = 0;
    	int z;
    	FD_ZERO(&readset);
    	FD_SET(fdosp, &readset);
    	MaxFd = fdosp + 1;
    	tv.tv_sec = 1;
    	tv.tv_usec = 0;
    	z = select(MaxFd,&readset,0,0,&tv);
    	if(z == -1)
    	{
    		syslog(LOG_ERR,"%s:select failed\n",LOG_TAG);
    		return -1;
    	}
    	char databuf[10];
    	int i = 0;
    	int ret;
    	//printf("start to read......\n");
    	while(1)
    	{
    		i = read(fdosp,databuf,1);
    		if(i > 0)
    		{
    			databuf[i] = '\0';
    			//printf("read data is %s\n",databuf);
    			ret = write(fdosp,databuf,1);
    			if(ret < 0) {
    				syslog(LOG_ERR,"%s:write data failed\n",LOG_TAG);
    			}
    #if 1
    			ret = write(fdc,databuf,sizeof(databuf));
    #endif
    		}
    	}
    	syslog(LOG_ERR,"%s:exit\n",LOG_TAG);
    	return 0;
    }

这个是amlogic下的，串口设备名为ttyS

驱动源码如下:

/*
     * linux/drivers/char/gzsd_input.c
     *
     * This program is free software; you can redistribute it and/or modify
     * it under the terms of the GNU General Public License version 2 as
     * published by the Free Software Foundation.
     */
    
    #include <linux/kernel.h>
    #include <linux/module.h>
    #include <linux/slab.h>
    #include <linux/input.h>
    #include <linux/init.h>
    #include <linux/errno.h>
    #include <linux/delay.h>
    #include <linux/miscdevice.h>
    #include <linux/platform_device.h>
    #include <asm/uaccess.h>
    
    #define DEVICE_NAME	"gzsd-input"
    static struct input_dev * input;
    
    static int s3c_Keycode[] = {KEY_A,KEY_B,KEY_C,KEY_D,KEY_E,KEY_F,KEY_G,KEY_H,KEY_I,KEY_J,KEY_K,KEY_L,
    			    KEY_M,KEY_N,KEY_O,KEY_P,KEY_Q,KEY_R,KEY_S,KEY_T,KEY_U,KEY_V,KEY_W,KEY_X,
    			    KEY_Y,KEY_Z,KEY_0,KEY_1,KEY_2,KEY_3,KEY_4,KEY_5,KEY_6,KEY_7,KEY_8,KEY_9,
    			    KEY_BACK,KEY_HOME,KEY_MENU,KEY_VOLUMEUP,KEY_VOLUMEDOWN,KEY_UP,KEY_DOWN,
    			    KEY_LEFT,KEY_RIGHT};
    #define MAX_BUTTON_CNT	(sizeof(s3c_Keycode)/sizeof(s3c_Keycode[0]))
    static ssize_t gzsd_input_write(struct file *filp, char *buffer,int len)
    {
    	int i = -1;
    	switch(buffer[0])
    	{
    		case 42:
    			i = 36;
    			break;
    		case 35:
    			i = 37;
    			break;
    		case 47:
    			i = 38;
    			break;
    		case 40:
    			i = 39;
    			break;
    		case 41:
    			i = 40;
    			break;
    		default:
    			break;
    	}
    	
    	if((buffer[0] > 47) && (buffer[0] < 58))
    		i = (buffer[0] - 48) + 26;
    	else if((buffer[0] > 96) && (buffer[0] < 123))
    		i = buffer[0] - 97;
    	else if((buffer[0] > 59) && (buffer[0] < 64))
    		i = (buffer[0] - 60) + 41;
    	if(i < 0) return -1;
    	input_report_key(input, s3c_Keycode[i], 1);
    	input_sync(input);
    	msleep(10);
    	input_report_key(input, s3c_Keycode[i], 0);
    	input_sync(input);
    	return 0;
    }
    
    static int gzsd_input_open(struct inode *inode, struct file *filp)
    {
    	return 0;
    }
    
    static int gzsd_input_release(struct inode *inode, struct file *filp)
    {
    	return 0;
    }
    
    static struct file_operations gzsd_dev_fops = {
    	.owner	=THIS_MODULE,
    	.open	=gzsd_input_open,
    	.write	=gzsd_input_write,	
    	.release	=gzsd_input_release,
    };
    
    static struct miscdevice misc = {
    	.minor	= MISC_DYNAMIC_MINOR,
    	.name	= "gzsd-input",
    	.fops	= &gzsd_dev_fops,
    };
    
    static int __init gzsd_input_init(void)
    {
    	int ret;
    	int i;
    	input = input_allocate_device();
    	if(!input) 
    		return -ENOMEM;
    
    	set_bit(EV_KEY, input->evbit);
    
    	for(i = 0; i < MAX_BUTTON_CNT; i++)
    		set_bit(s3c_Keycode[i], input->keybit);
    
    	input->name = "gzsd-input";
    	input->phys = "gzsd-input/input0";
    
    	input->id.bustype = BUS_HOST;
    	input->id.vendor = 0x0001;
    	input->id.product = 0x0001;
    	input->id.version = 0x0100;
    	input->keycode = s3c_Keycode;
    
    	if(input_register_device(input) != 0)
    	{
    		printk("gzsd-input input register device fail!!\n");
    
    		input_free_device(input);
    		return -ENODEV;
    	}
    
    	ret = misc_register(&misc);
    	printk(DEVICE_NAME"\tinitialized\n");
    	return ret;
    }
    
    static void __exit gzsd_input_exit(void)
    {
    	input_unregister_device(input);
    	misc_deregister(&misc);
    }
    
    module_init(gzsd_input_init);
    module_exit(gzsd_input_exit);
    
    MODULE_LICENSE("GPL");
    MODULE_AUTHOR("GZSD-TECH Inc.");

原理和源码其实很简单的，仅供初学者参考。

源码下载地址:[点击打开链接][Link 1]

[Link 1]: http://download.csdn.net/detail/hclydao/6414705