开发板上驱动程序模块的实现

来源：互联网发布：cef chromium linux 编辑：程序博客网时间：2024/06/03 19:07

一、在同一个文件夹中，写一个驱动模块程序（file.c文件）和一个Makefile

如：驱动模块程序：

                #include <linux/module.h>
                #include <linux/kernel.h>
                #include <linux/fs.h>
                #include <linux/init.h>
                #include <linux/delay.h>
                #include <linux/poll.h>
                #include <linux/irq.h>
                #include <asm/irq.h>
                #include <asm/io.h>
                 #include <linux/interrupt.h>
                #include <asm/uaccess.h>
                #include <mach/hardware.h>
                #include <linux/platform_device.h>
                #include <linux/cdev.h>
                #include <linux/miscdevice.h>
                #include <mach/gpio.h>
                #include <plat/gpio-cfg.h>
                #include <plat/regs-gpio.h>
                #include <plat/clock.h>
                #include <plat/cpu.h>
                #include <plat/regs-timer.h>
                #include <linux/device.h>
                #define DEVICE_NAME "ledtest"
                static struct class *led_class;

static int ledtest_open(struct inode *inode, struct file *file)
{
    unsigned int tmp;

    tmp = readl(S3C64XX_GPKCON);
    tmp =(tmp&~(0xffffU<<4)) | (0x1111U<<4);
    //(tmp & ~(0xffffU<<0)) | (0x1111U<<0);
    writel(tmp, S3C64XX_GPKCON);

    tmp = readl(S3C64XX_GPKDAT);
    tmp |= (0x0F << 4);
    writel(tmp, S3C64XX_GPKDAT);

    return 0;
}

static int ledtest_close(struct inode *inode, struct file *file)
{
    unsigned int tmp;

    tmp = readl(S3C64XX_GPKCON);
    tmp = (tmp & ~(0xffffU<<4));   //input function
    writel(tmp, S3C64XX_GPKCON);

    return 0;
}

static int ledtest_ioctl(struct inode *inode, struct file *file,
        unsigned int cmd, unsigned long arg)
{
    unsigned tmp;
    unsigned char num;
    num = *(unsigned char *)arg;

    //printk (DEVICE_NAME": %d %d\n", num, cmd);

    switch(cmd) {
        case 0:       //on
         if (num > 4) {
                   return -EINVAL;
           }
           tmp = readl(S3C64XX_GPKDAT);
           tmp &= ~(1 << (4 + num));
           //tmp |= ( cmd << (0 + num) );
           writel(tmp, S3C64XX_GPKDAT);
           return 0;
        case 1:       //off
         if (num > 4) {
                   return -EINVAL;
           }
         tmp = readl(S3C64XX_GPKDAT);
           tmp &= ~(1 << (4+ num));
           tmp |= ( cmd << (4 + num) );
           writel(tmp, S3C64XX_GPKDAT);
                return 0;
           default:
              return -EINVAL;
}
return 0;

}

static struct file_operations dev_fops = {
    .owner   = THIS_MODULE,
    .open   = ledtest_open,
    .ioctl   = ledtest_ioctl,
    .release   = ledtest_close,
};

static struct miscdevice misc = {
    .minor = MISC_DYNAMIC_MINOR,
    .name = DEVICE_NAME,
    .fops = &dev_fops,
};

static int __init dev_init(void)
{
    int ret;

    ret = misc_register(&misc);
    printk ("led driver initialized.\n");
    return ret;
}
static void __exit dev_exit(void)
{
    misc_deregister(&misc);
}

module_init(dev_init);
module_exit(dev_exit);
MODULE_LICENSE("GPL");

如Makefile:

        ifneq ($(KERNELRELEASE),)
        obj-m := s3c6410_leds.o
        else
                     PWD := $(shell pwd)
                     KERNEL_DIR :=/home/ghh/linux-2.6.28.6

       all:
      cd $(KERNEL_DIR); make SUBDIRS=$(PWD) modules
                        arm-linux-gcc -o leds_tese leds_test.c
       clean:
   rm -rf .*.cmd *.o *.mod.c *.ko .tmp_versions *.order *.symvers
endif

二、然后执行make命令（make -C /内核路径/   SUBDIRS=$(pwd) modules），执行该命令后会生成几个文件，其中有一个是.KO文件，这个文件是用来做加载驱动模块用的

三、在同一文件中，写一个应用程序和一个Makefile

如：应用程序

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>

#define PATH "/dev/ledtest"   //device file
#define LED_ON   0
#define LED_OFF 1

int main(void)
{
   int fd, count;
   unsigned char num;
   unsigned char led_num[4] = {0, 1, 2, 3};

   fd = open("/dev/ledtest", 0);
   if (fd < 0) {
       printf("Failed to open leds driver\n");
       exit(1);
   }

   count = 4;
   while(1) {
       ioctl(fd, LED_ON, &led_num[count%4]);
       ioctl(fd, LED_OFF, &led_num[(count - 1)%4]);
       usleep(500000);
       count++;
       ioctl(fd, LED_ON, &led_num[count%4]);
       ioctl(fd, LED_OFF, &led_num[(count - 1)%4]);
       usleep(500000);
   }

   close(fd);

   return 0;
}

Makefile:

CROSS_COMPILE = /opt/FriendlyARM/toolschain/4.5.1/bin/arm-linux-
CC = $(CROSS_COMPILE)gcc
AR = $(CROSS_COMPILE)ar

ALL : leds_test

leds_test: leds_test.c
   $(CC) -o leds_test   leds_test.c

clean :
   rm -rf leds_test *~

四、然后执行make命令，就会生成一个可执行文件

五、启动NFS在宿主机上，并把前面生成的.KO文件和可执行文件拷坝到共享目录下

六、打开开发板的终端，然后挂载共享文件目录，而挂载共享文件有两种方式：例如：

1、mount -o nolock 192.168.3.150:/home/share /mnt

2、mount -t nfs -o intr,nolock,wsize=1024,rsize=1024 192.168/3/150:/home/share /mnt

七、挂载成功后，就进入/mnt进行加载.KO文件

#cd /mnt

#insmod file.ko

#lsmod //查看是否加载成功

#lsmod | head -参数 //可查看前面的模块

#dmesg | tail -参数 //查看尾的模块，并显示模块内容

八、在开发板上加载模块成功后，就执行应用程序生成的可执行文件，如：