s3c2410板的linux下AD驱动程序

上传一个AD的驱动程序,虽然简单,但可能给你启发的! //下载地址http://www.hzlitai.com.cn/bbs/dispbbs.asp?boardid=11&Id=4687&page=2 作者：tymanium 它是一个采集ad的0号通道的驱动程序,将驱动程序和测试程序编译好之后,在2410开发板上加一个可调电阻产生分压,并将分压接到ain0上,这时运行sample &就可以采集ain0上的电压了.文件里有说明用法,如下: /* ad.c * copyright (c) by tymanium from china * this is a device module file used for sbc2410 * it can drive ad convertor, yes it's very easy */ /*usage: 1. arm-linux-gcc -d__kernel__ -i/friendly-arm/kernel/include - dkbuild_badename=test -dmodule -c -o ad.o ad.c 2. arm-linux-gcc -o sample sample.c 3. copy ad.o and sample to /lib/ and /bin/ respectively 4. power on sbc2410 ,and then active your bash 5. run #insmod /lib/ad.o and #mknod /dev/ad c 200 0 6. here run #sample &, now you can sample the ain0 */ #include <linux/config.h> #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/miscdevice.h> #include <linux/sched.h> #include <linux/delay.h> #include <linux/poll.h> #include <linux/spinlock.h> #include <linux/irq.h> #include <linux/delay.h> #include <asm/hardware.h> #define device_name "ad_test" // #define ioport_major 200 /*this function is called whenever a process open the device file*/ static int ad_open(struct inode *inode, struct file *filp) { adccon=0x4c40; // adctsc =0x58; // adcdly=0x01; return 0; } /*this function is called when a process call function ioctl( )*/ static int ad_ctl_ioctl(struct inode *inode, struct file *filp, unsigned int command, unsigned long arg) { switch(command){ case 0: printk("the adccon register is %x \t", adccon); return adcdat0; //get your sample code case 1: adccon |= 1; //start your ad return 0; } return -einval; } /*this function is called when a process close our device file*/ static int ad_release(struct inode *inode, struct file *filp) { } static struct file_operations ad_ctl_fops={ ioctl : ad_ctl_ioctl, open : ad_open, release : ad_release, }; /*this function is called when you use insmod */ static int __init ad_init(void) { int ret; unsigned long val=mpllcon;; ret=register_chrdev(ioport_major, device_name, &ad_ctl_fops); if (ret < 0) { printk(device_name " can't register major number\n"); return ret; } printk("the val is %lx \n",val); printk("the mpllcon register value is %lx \n",mpllcon); printk("the clkdivn register value is %lx \n",clkdivn); printk("the clkcon register value is %lx \n",clkcon); return ret; } /*this function is called when you use rmmod*/ static void __exit ad_cleanup(void) { unregister_chrdev(ioport_major, device_name); } module_init(ad_init); module_exit(ad_cleanup); module_license("gpl"); 下面是sample.c 文件 #include<stdio.h> #include<stdlib.h> #include<sys/ioctl.h> #include<unistd.h> #define device_adtest "/dev/ad" int main( ) { int fd,ret; int val=-1; float voltage; if((fd=open(device_adtest,0))<0){ perror("can not open device"); exit(1); } while(1){ ioctl(fd,1,0); sleep(1); ret=ioctl(fd,0,0); ret &= 0x3ff; voltage=(float)ret; voltage=(voltage-1023)*(-1)*3.3/1023; printf("the sampling voltage is %f v\t \n",voltage); } close(fd); return 0; }