/*
- * drivers/usb/file.c
+ * drivers/usb/core/file.c
*
* (C) Copyright Linus Torvalds 1999
* (C) Copyright Johannes Erdfelt 1999-2001
*
*/
-#include <linux/config.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include "usb.h"
#define MAX_USB_MINORS 256
-static struct file_operations *usb_minors[MAX_USB_MINORS];
+static const struct file_operations *usb_minors[MAX_USB_MINORS];
static DEFINE_SPINLOCK(minor_lock);
static int usb_open(struct inode * inode, struct file * file)
{
int minor = iminor(inode);
- struct file_operations *c;
+ const struct file_operations *c;
int err = -ENODEV;
- struct file_operations *old_fops, *new_fops = NULL;
+ const struct file_operations *old_fops, *new_fops = NULL;
spin_lock (&minor_lock);
c = usb_minors[minor];
return err;
}
-static struct file_operations usb_fops = {
+static const struct file_operations usb_fops = {
.owner = THIS_MODULE,
.open = usb_open,
};
-static struct class *usb_class;
+static struct usb_class {
+ struct kref kref;
+ struct class *class;
+} *usb_class;
-int usb_major_init(void)
+static int init_usb_class(void)
{
- int error;
+ int result = 0;
- error = register_chrdev(USB_MAJOR, "usb", &usb_fops);
- if (error) {
- err("unable to get major %d for usb devices", USB_MAJOR);
- goto out;
+ if (usb_class != NULL) {
+ kref_get(&usb_class->kref);
+ goto exit;
+ }
+
+ usb_class = kmalloc(sizeof(*usb_class), GFP_KERNEL);
+ if (!usb_class) {
+ result = -ENOMEM;
+ goto exit;
}
- usb_class = class_create(THIS_MODULE, "usb");
- if (IS_ERR(usb_class)) {
- error = PTR_ERR(usb_class);
+ kref_init(&usb_class->kref);
+ usb_class->class = class_create(THIS_MODULE, "usb");
+ if (IS_ERR(usb_class->class)) {
+ result = IS_ERR(usb_class->class);
err("class_create failed for usb devices");
- unregister_chrdev(USB_MAJOR, "usb");
- goto out;
+ kfree(usb_class);
+ usb_class = NULL;
}
-out:
+exit:
+ return result;
+}
+
+static void release_usb_class(struct kref *kref)
+{
+ /* Ok, we cheat as we know we only have one usb_class */
+ class_destroy(usb_class->class);
+ kfree(usb_class);
+ usb_class = NULL;
+}
+
+static void destroy_usb_class(void)
+{
+ if (usb_class)
+ kref_put(&usb_class->kref, release_usb_class);
+}
+
+int usb_major_init(void)
+{
+ int error;
+
+ error = register_chrdev(USB_MAJOR, "usb", &usb_fops);
+ if (error)
+ err("unable to get major %d for usb devices", USB_MAJOR);
+
return error;
}
void usb_major_cleanup(void)
{
- class_destroy(usb_class);
unregister_chrdev(USB_MAJOR, "usb");
}
}
spin_unlock (&minor_lock);
+ if (retval)
+ goto exit;
+
+ retval = init_usb_class();
if (retval)
goto exit;
++temp;
else
temp = name;
- intf->class_dev = class_device_create(usb_class, NULL,
+ intf->class_dev = class_device_create(usb_class->class, NULL,
MKDEV(USB_MAJOR, minor),
&intf->dev, "%s", temp);
if (IS_ERR(intf->class_dev)) {
spin_unlock (&minor_lock);
snprintf(name, BUS_ID_SIZE, class_driver->name, intf->minor - minor_base);
- class_device_destroy(usb_class, MKDEV(USB_MAJOR, intf->minor));
+ class_device_destroy(usb_class->class, MKDEV(USB_MAJOR, intf->minor));
intf->class_dev = NULL;
intf->minor = -1;
+ destroy_usb_class();
}
EXPORT_SYMBOL(usb_deregister_dev);