kbdriver.c~

一个以s3c2410为核心的ARM板键盘驱动程序的例子

#define	__KERNEL__
#define	  MODULE
#include <linux/module.h>
#include <linux/version.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/delay.h>
#include <linux/poll.h>
#include <asm/uaccess.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/string.h>
#include <asm/bitops.h>
#include <asm/io.h>
#include <linux/errno.h>
#include <linux/tqueue.h>
#include <linux/wait.h>
#include <asm/irq.h>
#include <asm/arch/hardware.h>
#include <asm/arch/irqs.h>
#include <linux/devfs_fs_kernel.h>
#include "kbDriver.h"

void cleanup_module(void);
int kbDriver_open(struct inode * inode, struct file * filp);
int kbDriver_release(struct inode * inode, struct file * filp);
ssize_t kbDriver_read(struct file * filp, char * buf, size_t count, loff_t * l);
ssize_t kbDriver_write(struct file * filp,const char * buf,size_t count,loff_t * l);
unsigned int kbDriver_select(struct file *filp,struct poll_table_struct *wait);

DECLARE_WAIT_QUEUE_HEAD(kb_wait);

struct file_operations kbDriver_fops = {
	open:           kbDriver_open,
	release:        kbDriver_release,
	poll:           kbDriver_select,
	read:           kbDriver_read,
	write:	        kbDriver_write,
};


int kbDriver_open(struct inode * inode, struct file * filp)
{
	gpioc_base=ioremap_nocache(GPIOC,GPIOLEN); //get virtual address
	BWSCON=((BWSCON&(0xfffff0ff))|(0x0));
	BANKCON2=0x7ff0;
//键盘时钟初始化
	GPECON = (GPECON)&(0x0fffffff);
	GPEUP  = (GPECON)&(0xffff3fff);
	GPECON = (GPECON)|(0xa0000000);
	GPEUP  = (GPECON)|(0x0000c000);
	CLKCON = (CLKCON)& (0xfffeffff);
	CLKCON = (CLKCON)| (0x00010000);
	__REG(0x54000000) = 0x4f;
	__REG(0x54000004) = 0xf0;
//	IICCON = 0x4f; 
//	IICSTAT = 0xf0; 
	MOD_INC_USE_COUNT;
	return 0;
}

int kbDriver_release(struct inode * inode,struct file * filp)
{
	iounmap(gpioc_base);
	MOD_DEC_USE_COUNT;
	cleanup_module();
	return 0;
}

ssize_t kbDriver_read(struct file * filp, char * buf, size_t count, loff_t * l)
{
	if(!keyIntFlag)
		return -EAGAIN;

	*buf=*(gpioc_base);
	keyIntFlag=0;
	return 0;
}

ssize_t kbDriver_write(struct file * filp, const char * buf, size_t count, loff_t * l)
{
	return 0;
}


unsigned int kbDriver_select(struct file *filp,struct poll_table_struct *wait)
{
	if(keyIntFlag)
		return 1;
	poll_wait(filp, &kb_wait, wait);
	return 0;
}

void key_irq_handler(int irq,void *dev_id,struct pt_regs *regs){
	disable_irq(2);
	keyIntFlag=1;
	wake_up_interruptible(&kb_wait);
	enable_irq(2);
}
int init_module(void){	
	unsigned int result = 0;

	result = register_chrdev(CHARDRIVER_MAJOR, CHARDRIVER_NAME, &kbDriver_fops);
	if (result < 0){
		unregister_chrdev(CHARDRIVER_MAJOR,CHARDRIVER_NAME);
	  	return result;
	}else{
		if(set_external_irq(2,2,1)){
			return -1;
		}
		if(request_irq(
    				2,  
				key_irq_handler,  
				SA_INTERRUPT,
				"key_irq_handler", 
				NULL)
		){
			return -1;
		}
		printk(KERN_INFO "kb driver is ok!\n");
	}
	return 0;
}

void cleanup_module(void)
{
	disable_irq(2);
	free_irq(2,NULL);
  	unregister_chrdev(CHARDRIVER_MAJOR, CHARDRIVER_NAME);
	return;
}