270key2.c~

270的GPIO驱动是一个GPIO按键的驱动

/*
 * 270keydriver  Copyright (C) 2008, Aumed
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>

#include <linux/kernel.h>   /* printk() */
#include <linux/slab.h>   /* kmalloc() */
#include <linux/fs.h>       /* everything... */
#include <linux/errno.h>    /* error codes */
#include <linux/types.h>    /* size_t */
#include <linux/mm.h>
#include <linux/kdev_t.h>
#include <linux/cdev.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/arch/pxa-regs.h>
#include <asm/arch/mainstone.h>

static int key2_major = 131;
module_param(key2_major, int, 0);

MODULE_AUTHOR("MCL");
MODULE_LICENSE("Dual BSD/GPL");

static int key2_open (struct inode *inode, struct file *filp)
{
	return 0;
}

static ssize_t key2_read(struct file *file, char  *buf, size_t count, loff_t *ppos)
{
        int data=0;
	//while(!(GPLR3&0x08));
	while(!(GEDR3&0x08));
	data = 1;
	if(copy_to_user(buf, &data, sizeof(data)))
			return -EFAULT;
	
	return (sizeof(int));

}

ssize_t key2_write(struct file *file, const char __user *buff, size_t count, loff_t *offp)
{

	return 0;
}

static int key2_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	
	return 0;
}

static int key2_release(struct inode *node, struct file *file)
{
	return 0;
}

/*
 * Set up the cdev structure for a device.
 */
static void key2_setup_cdev(struct cdev *dev, int minor,
		struct file_operations *fops)
{
	int err, devno = MKDEV(key2_major, minor);
    
	cdev_init(dev, fops);
	dev->owner = THIS_MODULE;
	dev->ops = fops;
	err = cdev_add (dev, devno, 1);
	/* Fail gracefully if need be */
	if (err)
		printk (KERN_NOTICE "Error %d adding key2%d", err, minor);

}


/*
 * Our various sub-devices.
 */
/* Device 0 uses remap_pfn_range */
static struct file_operations key2_remap_ops = {
	.owner   = THIS_MODULE,
	.open    = key2_open,
	.release = key2_release,
	.read    = key2_read,
	.write   = key2_write,
	.ioctl   = key2_ioctl,	
};

/*
 * We export two simple devices.  There's no need for us to maintain any
 * special housekeeping info, so we just deal with raw cdevs.
 */
static struct cdev Key2Devs;

/*
 * Module housekeeping.
 */
static int key2_init(void)
{
	int result;
	dev_t dev = MKDEV(key2_major, 0);

	/* Figure out our device number. */
	if (key2_major)
		result = register_chrdev_region(dev, 1, "key2");
	else {
		result = alloc_chrdev_region(&dev, 0, 1, "key2");
		key2_major = MAJOR(dev);
	}
	if (result < 0) {
		printk(KERN_WARNING "key2: unable to get major %d\n", key2_major);
		return result;
	}
	if (key2_major == 0)
		key2_major = result;

	GAFR3_L=GAFR3_L & 0xFFF3FFFF;
	PSSR=PSSR & 0xFFFFFFDF;
	GPDR3=GPDR3& 0xFFFFFDFF;
	GRER3=GRER3& 0xFFFFFDFF;
	//GFER3=GFER3& 0xFFFFFFF7;
	  GFER3=GFER3 | (1<<3);
         /* Now set up two cdevs. */
	key2_setup_cdev(&Key2Devs, 0, &key2_remap_ops);
	printk("key2 device installed, with major %d\n", key2_major);
	return 0;
}


static void key2_cleanup(void)
{
	cdev_del(&Key2Devs);
	unregister_chrdev_region(MKDEV(key2_major, 0), 2);
	printk("key2 device uninstalled\n");
}


module_init(key2_init);
module_exit(key2_cleanup);