mydriver.c

来自「在frv环境下开发板的led驱动」· C语言 代码 · 共 76 行

#define MODULE
#define __KERNEL__
#include<linux/kernel.h>
#include<linux/module.h>
#include <linux/fs.h>
#include <asm/uaccess.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <asm/irq.h>
#include <asm/smplock.h>
#include <linux/coda.h>
#include <linux/config.h>
#include <linux/sched.h>
#include <linux/devfs_fs_kernel.h>
#include <asm/ioctl.h>
#define FLED_ADDR (volatile unsigned short *)0x20000022
#define FSWR_ADDR (volatile unsigned short *)0x20000028
#define FPGA_SW_IOC_MAGIC 0xdc
#define FPGA_SWITCH_READ _IOR(FPGA_SW_IOC_MAGIC,0,unsigned short)
#define FPGA_LED _IOW(FPGA_SW_IOC_MAGIC,1,unsigned short)
#define MAJOR 240
#define DEVICE_NAME "keyled"

static int Device_Open=0;
static int keyled_open(struct inode *inode ,struct file *file)
{ 
	printk("<1>keyled driver opened\n");
    MOD_INC_USE_COUNT;
    return 0;
}

static int keyled_release(struct inode *inode ,struct file *file)
{  
   	MOD_DEC_USE_COUNT;
   	return 0;
}

static int keyled_ioctl(struct inode *inode,struct file *file,unsigned int cmd ,unsigned long arg)
{
	unsigned short sw_val;
	switch(cmd)
	{
		case FPGA_SWITCH_READ: 	sw_val=*((volatile unsigned short *)(FSWR_ADDR));
					*(int*) arg=sw_val;
					__asm__ __volatile__("membar") ;
					break;
	 	case FPGA_LED:	        *((volatile unsigned short*)(FLED_ADDR))=arg;          	 				__asm__ __volatile__("membar");
					break;
	        default:		printk("No such command!\n");
					return -EINVAL;
        }
}

struct file_operations keyled_fops=
{
        open:           keyled_open,
        release:        keyled_release,
        ioctl:          keyled_ioctl,
};

static int keyled_init(void)
{
	if(register_chrdev(MAJOR,DEVICE_NAME,&keyled_fops)>=0)
	printk("<1>Key and Led OK\n");
	return 0;
}

static void keyled_exit(void)
{
	if(unregister_chrdev(MAJOR,DEVICE_NAME)>=0)
	printk("<1>Programme Over\n");
}

module_init(keyled_init);
module_exit(keyled_exit);