devices.c

#include <linux/cdev.h>
#include <linux/semaphore.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/kdev_t.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include "scull.h"

int create_dev(void)
{

        int result = -1; 
	dev_t dev;

        if(scull_major){
                dev = MKDEV(scull_major, scull_minor);
                result = register_chrdev_region(dev, scull_nr_devs, "scull_pipe");
        }else{
                result = alloc_chrdev_region(&dev, scull_minor, scull_nr_devs, "scull_pipe");
                scull_major = MAJOR(dev);
        }   

        if(result < 0){ 
                /* clean up */
                printk(KERN_WARNING "scull_pipe: Can't get major device number %d\n", scull_major);
        }   
	return result;

}

/* seq_file proc methods */


//static void *scull_seq_start(struct seq_file *s, loff_t *pos) /* pos is an index to a scull_devices array */
//{
//	if (*pos >= scull_nr_devs)
//		return NULL; /* no more to read */
//	
//	return scull_devices + *pos;
//}
//
//static void *scull_seq_next(struct seq_file *s, void *v, loff_t *pos) /* *v is the iterator returned by previous call to start or next */
//{
//	(*pos)++;
//	if (*pos >= scull_nr_devs){
//		return NULL;
//	}
//	return scull_devices + *pos; 
//}
//
//static void *scull_seq_stop(struct seq_file *s, void *v)
//{
//
//}
//
//static int scull_seq_show(struct seq_file *s, void *v)
//{
//	struct scull_dev *dev = (struct scull_dev *) v;
//	struct scull_qset *d;
//	int i;
//
//	if(down_interruptible(&dev->sem))
//		return -ERESTARTSYS;
//
//	seq_printf(s, "\nDevice %i: qset %i, q %i, sz %li\n",
//		(int) (dev - scull_devices), dev->qset,
//		dev->quantum, dev->size);
//
//	for(d = dev->data; d; d = d->next) { /* scan the list */
//		seq_printf(s, "   item at %p, qset at %p\n", d, d->data);
//		if(d->data && !d->next) /*dump only the last item */
//			for(i=0; i < dev->qset; i++){
//				if(d->data[i])
//					seq_printf(s, "     % 4i: %8p\n",
//						i, d->data[i]);
//			}
//	}
//	up(&dev->sem);
//	return 0;
//}
//
//
//
//
//
//static struct seq_operations scull_seq_ops = {
//	.start = scull_seq_start,
//	.next  = scull_seq_next,
//	.show  = scull_seq_show,
//	.stop  = scull_seq_stop
//};
//
//static int scull_proc_open(struct inode *inode, struct file *file)
//{
//	return seq_open(file, &scull_seq_ops);
//}
//
//static struct file_operations scull_proc_ops = {
//	.owner = THIS_MODULE,
//	.open  = scull_proc_open,
//	.read  = seq_read,
//	.llseek = seq_lseek,
//	.release = seq_release
//};
//
//
//void procfile_setup(void)
//{
//	struct proc_dir_entry *entry;
//
//	entry = create_proc_entry("scullseq", 0, NULL);
//
//	if(entry)
//		entry->proc_fops = &scull_proc_ops;
//}
//
///* No clean up work to do, no stop method then */