gpio_drv.c

本程序是linux下写arm9200的gpio的程序及makefile文件

/* driver/char/gpio_drv.c 
 * 
 * This file provide IO reading and writing from user space.
 * Pls create some device file in diretory /dev/ppcflash whose major is 218.
 * This driver support 0-255 devices. In user space user can read and write
 * IO through open and ioctl function provided by glibc.
 * 
 * Any problem pls contact [e-mail]
 */
#include <linux/fs.h>
#include <linux/iobuf.h>
#include <linux/major.h>
#include <linux/blkdev.h>
#include <linux/capability.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>
#include <asm/hardware.h>
#include <asm/arch/cpu_s3c2410.h>
#include <asm/io.h>
#include "gpio_drv.h" 
#include <linux/vmalloc.h>
#include <linux/module.h> //wpq insmod gpio

#define dprintk(x...) 

#define IOPORT_MAJOR 220
//#define gpio_devfs_dir
/*define the ppcflash major node is 220*/


typedef char ioport_device_t;
devfs_handle_t gpio_devfs_dir;


static ioport_device_t gpio_devices[256];
long port_addr;

int	gpio_open(struct inode *, struct file *);
int	gpio_release(struct inode *, struct file *);
int	gpio_ctl_ioctl(struct inode *, struct file *, unsigned int, unsigned long);
//#################################################################
//wpq mod
/*
static struct file_operations gpio_fops = {
	open:		gpio_open,
	release:	gpio_release,
};
*/
static struct file_operations gpio_ctl_fops = {
	ioctl:		gpio_ctl_ioctl,
	open:		gpio_open,
	release:	gpio_release,
};

/*int __init gpio_init(void)
{
	
	register_chrdev(IOPORT_MAJOR, "gpiotest", &gpio_ctl_fops);
	return 0;
*/
/* 
 * Open/close code for raw IO.
 */

gpio_open(struct inode *inode, struct file *filp)
{
	int minor;

	minor = MINOR(inode->i_rdev);
/*	if (ioport_devices[minor].io_lock) {
		printk("Device is busy\n");
		return -1;
	}*/
	set_gpio_ctrl(GPIO_MODE_OUT | GPIO_C6);
#if 0 
	(void *)(port_addr) = ioremap(0x56000020,0x8);
	printk("port addr is %x\n",port_addr);
	printk("port addr is %x\n", GPCON(GPIO_MODE_OUT | GPIO_C6));
//	*(volatile unsigned int *)(port_addr)|=0x00008000;
//	set_gpio_ctrl(GPIO_MODE_VD);
//	*(volatile unsigned int *)(0x56000020)|=0x00008000;
#endif
	printk("open ok\n");
	gpio_devices[minor]++;
	return 0;

}
//__ioremap
int gpio_release(struct inode *inode, struct file *filp)
{
	int minor;
	
	minor = MINOR(inode->i_rdev);
	if (gpio_devices[minor])
		gpio_devices[minor]--;
//	*(volatile unsigned int *)(0x56000020)&=~0x00008000;
	printk("release ok\n");
	return 0;
}



/*
 * Deal with ioctls against the raw-device control interface, to bind
 * and unbind other raw devices.  
 */


int gpio_ctl_ioctl(struct inode *inode, 
		  struct file *flip,
		  unsigned int command, 
		  unsigned long arg)
{
	int err = 0;
	int minor = MINOR(inode->i_rdev);
	
	switch (command) {
	case IOWRITE:
//		*(volatile unsigned int *)(port_addr+1)|=0x00000080;
		write_gpio_bit(GPIO_MODE_OUT | GPIO_C6,1);
		printk("HHTECH: here write ok1111\n");
		return 0;
	case IOCLEAR:
		write_gpio_bit(GPIO_MODE_OUT | GPIO_C6,0);
//		*(volatile unsigned int *)(port_addr+1)&=~0x00000080;
		printk("clear ok\n");
		return 0;
	default:
		err = -EINVAL;
	}

	return err;
}
//##########################################################
//hhtech add it by wpq ,2005 01 28
//
static int __init
gpio_init (void)
{
 //       gpio_devfs_dir = devfs_mk_dir(NULL, "gpiotest", NULL);
//        if(!gpio_devfs_dir)
  //              return -EBUSY;

//	register_chrdev(IOPORT_MAJOR, "gpiotest", &gpio_ctl_fops);
//devfs_register(IOPORT_MAJOR, "gpiotest", &gpio_ctl_fops);
//############################################################################
//
//hhtech add it by wpq
//date:20050128
//The" devfs"is very important!!!register file command
//note:devfs and register ;but ,devfs= register+mknod
//Here isn't use :mknod  /dev/gpiotest c 220 0
        gpio_devfs_dir= devfs_register(NULL,"gpiotest",DEVFS_FL_DEFAULT,IOPORT_MAJOR,
                             0, S_IFCHR |S_IRUSR |S_IWUSR |S_IRGRP |S_IWGRP,
                             &gpio_ctl_fops, NULL);
	
        printk ("gpio driver installed OK\n");
        printk ("Test is starting!\n");
        return 0;
}


static void __exit
gpio_exit(void)
{
        devfs_unregister(gpio_devfs_dir);
        printk("gpio driver uninstalled OK\n");
}



module_init(gpio_init);

module_exit(gpio_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("wpq");
MODULE_DESCRIPTION("gpio Driver for arm9_edu");