/* * Accelerometer demo driver for Linux * * Copyright (C) 2002 Alvin Tang <alvin.tang@intel.com> * Copyright (C) 2007 Socrates <yangyj.ee@gmail.com> * * This driver allows you to access the contents of accelerometer sensor on * the Sitsang board. * * The device file for Accelerometer is "/dev/acce". You can create this file * handly by  * 		mknod /dev/acce c 10 241 * * Example code for reading data in user space: * ------------------------------------------------------------------- * 		struct acce_point{ * 			unsigned int x; * 			unsigned int y; * 		}tmp; * 		 *		int main(int argc, char **argv) *		{ *			.... *			 * 			fd=open("/dev/acce", O_RDONLY); * 			.... * 			 * 			read(fd, &tmp, sizeof(acce_point)); * 			.... * 			 * 			close(fd); //close device file * 		} * -------------------------------------------------------------------- * 		 */#define SITSANG_ACCE_VERSION		"1.1"#define SITSANG_ACCE_MINOR	241#include <linux/module.h>#include <linux/sched.h>#include <linux/types.h>#include <linux/errno.h>#include <linux/fs.h>#include <linux/miscdevice.h>#include <linux/fcntl.h>#include <linux/init.h>#include <asm/io.h>#include <asm/uaccess.h>#include <asm/hardware.h>#include <asm/arch/pxa-regs.h>#include <asm/arch/sitsang.h>#include <asm/system.h>#include <linux/delay.h>static struct acce_point{	unsigned int x;	unsigned int y;}acce_status;static ssize_t acce_read(struct file * file,	char * buf, size_t count, loff_t *ppos ){	ssize_t ret = 0;		while ( ret + sizeof (struct acce_point) <= count )  {		acce_status.x = SITSANG_AXHR_RD & 0x0000ffff;		acce_status.y = SITSANG_AYHR_RD & 0x0000ffff;		if (copy_to_user(buf + ret, &acce_status, sizeof (struct acce_point))){			printk("copy to user failed\n");			return -EFAULT;		}				ret += sizeof (struct acce_point);	}		return ret;}static int acce_open( struct inode *inode, struct file *file ){	SITSANG_PCR_RW |= SITSANG_PCR_ACC_ON | SITSANG_PCR_PER_ON;	mdelay(100);	return 0;}static int acce_release( struct inode *inode, struct file *file ){	SITSANG_PCR_RW &= ~SITSANG_PCR_ACC_ON;	return 0;}static struct file_operations acce_fops = {	.owner =	THIS_MODULE,	.read =		acce_read,	.open =		acce_open,	.release =	acce_release,};static struct miscdevice acce_dev = {	SITSANG_ACCE_MINOR,	"accelerometer",	&acce_fops};static int __init acce_init(void){	int ret;	ret = misc_register( &acce_dev );	if (ret) {		printk(KERN_ERR "acce: can't misc_register on minor=%d\n", SITSANG_ACCE_MINOR);		goto out;	}	ret = 0;	printk(KERN_INFO "Sitsang Accelerometer Sensor driver v" SITSANG_ACCE_VERSION "\n");out:	return( ret );}static void __exit acce_cleanup_module (void){	misc_deregister( &acce_dev );}module_init(acce_init);module_exit(acce_cleanup_module);MODULE_AUTHOR("Alvin Tang <alvin.tang@intel.com>");MODULE_DESCRIPTION("Accelerometer Sensor Driver for Sitsang Board");MODULE_LICENSE("GPL");