第一个linux驱动程序

#include <linux/module.h>
#include <linux/moduleloader.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/gfp.h>

#include <asm/pgtable.h>
#include <asm/sections.h>
#include <asm/unwind.h>

#include <linux/init.h>
#include <asm/io.h>//arch/arm/include/asm/io.h
#include <linux/ioport.h>

#include <linux/types.h>
#include <linux/cdev.h>
#include <asm/uaccess.h>
#include <linux/device.h>

#define key_paddr 0xE0200C40
#define led_paddr 0xE0200280

unsigned long *key_ctrl_vaddr=NULL;
unsigned long *key_data_vaddr=NULL;
unsigned long *led_ctrl_vaddr=NULL;
unsigned long *led_data_vaddr=NULL;

static unsigned int this_major = 250;
static unsigned int this_minor = 0;

struct class *key_led_class;

static int key_led_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long args)
{
    unsigned int val;
    
    switch(cmd)
    {
        printk("%d-%d\n",cmd,args);
        //led on
        case 0:
               val = ioread32(led_data_vaddr);
            val &=~(0x1<<args);
            
            iowrite32(val,led_data_vaddr);
            break;
        case 1:
            val = ioread32(led_data_vaddr);
            val |=(0x1<<args);
            iowrite32(val,led_data_vaddr);
            break;
        default:
            printk("cmd is wrong, 0-->LED OFF  1-->LED ON \n");    
            return -EINVAL;
    }
    return 0;
}
static int key_led_open (struct inode *inode, struct file *file)
{
    printk("open!\n");
    return 0;
}
static int key_led_release (struct inode *inode, struct file *file)
{
    printk("release!\n");
    return 0;
}
struct file_operations key_led_fops={
    .owner = THIS_MODULE,
    .open = key_led_open,
    .release = key_led_release,
    .ioctl = key_led_ioctl,
};

static __init int key_led_init(void)
{
    printk("key_led_init!\n");
    int result;
    result = register_chrdev(this_major, "key_led", &key_led_fops);
    if(result<0)
    {
        printk("register_chrdev error!\n");
        goto register_chrdev_error;
    }
    key_led_class = class_create(THIS_MODULE, "key_led");
    if(IS_ERR(key_led_class))
    {
        printk("Err:failed in creating class.\n");
        goto class_create_error;
    }    
    if(device_create(key_led_class,NULL,MKDEV(this_major, this_minor), NULL, "key_led")==NULL)
    {
        printk("device_create_error!\n");
        goto device_create_error;
    }
    
    struct resource *resource;
    resource=request_mem_region(key_paddr, 8, "key_men");
    if(resource==NULL)
    {
        printk("request_mem_region_error!\n");
        goto request_mem_region;
    }
    resource=request_mem_region(led_paddr, 8, "led men");
    if(resource==NULL)
    {
        printk("request_mem_region_error!\n");
        goto request_mem_region;
    }

    key_ctrl_vaddr = ioremap(key_paddr, 8);
    key_data_vaddr = key_ctrl_vaddr+1;
    
    led_ctrl_vaddr = ioremap(led_paddr, 8);
    led_data_vaddr = led_ctrl_vaddr+1;

    if(key_ctrl_vaddr==NULL ||led_ctrl_vaddr ==NULL)
    {
        printk("ioremap_error!\n");
        goto ioremap_error;
    }
    //key_ctrl,input method
    unsigned int val;
    val = ioread32(key_ctrl_vaddr);
    val &= ~(0xf<<0);
    iowrite32(val,key_ctrl_vaddr);

    //led_ctrl,output method
    val = ioread32(led_ctrl_vaddr);
    val &=~(0xf<<0);
    val |= (0x1<<0);
    iowrite32(val,led_ctrl_vaddr);

    //led_data
    val = ioread32(led_data_vaddr);
    val |=(0x1<<0);
    iowrite32(val,led_data_vaddr);
    
    return 0;

    
ioremap_error:
    release_mem_region(key_paddr, 8);
    release_mem_region(led_paddr, 8);
request_mem_region:
    device_destroy(key_led_class, MKDEV(this_major, this_minor));
device_create_error:
    class_destroy(key_led_class);
class_create_error:
    unregister_chrdev(this_major,"key_led");
register_chrdev_error:
    return -1;
}
static __exit void key_led_exit(void)
{
    printk("key_led_exit!\n");
    unsigned int val;
    val = ioread32(led_data_vaddr);
    val |= (0x1<<0);
    iowrite32(val,led_data_vaddr);

    iounmap(key_ctrl_vaddr);
    iounmap(led_ctrl_vaddr);

    release_mem_region(key_paddr, 8);
    release_mem_region(led_paddr, 8);

    device_destroy(key_led_class, MKDEV(this_major, this_minor));
    class_destroy(key_led_class);

    unregister_chrdev(this_major,"key_led");
}

module_init(key_led_init);
module_exit(key_led_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Achilles");

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/fcntl.h>


int on ;
int ledn;

int main(int argc,char** argv)
{
    printf("app!\n");

    if(argc > 3|| sscanf(argv[2], "%d",&ledn)!=1||sscanf(argv[1],"%d",&on)!=1)
    {
        printf("error: format: ./app on ledn\n");
        return -1;
    }
    int fd = open("/dev/key_led",O_RDWR);
    
    printf("%d-%d\n",on,ledn);
    ioctl(fd, ledn, on);
    
    close(fd);
    return 0;
}

obj-m = module_key_led.o

KDIR = ~/kernel_src

all:
    cp ~/share/*.c .
    make -C $(KDIR) M=`pwd` modules
    arm-linux-gcc app.c -o app
    cp *.ko ~/share
    cp app ~/share
clean:
    make -C $(KDIR) M=`pwd` modules clean