/*
- * 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/devfs_fs_kernel.h>
-#include <linux/spinlock.h>
#include <linux/errno.h>
-
-#ifdef CONFIG_USB_DEBUG
- #define DEBUG
-#else
- #undef DEBUG
-#endif
+#include <linux/rwsem.h>
#include <linux/usb.h>
#include "usb.h"
#define MAX_USB_MINORS 256
-static struct file_operations *usb_minors[MAX_USB_MINORS];
-static DEFINE_SPINLOCK(minor_lock);
+static const struct file_operations *usb_minors[MAX_USB_MINORS];
+static DECLARE_RWSEM(minor_rwsem);
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);
+ down_read(&minor_rwsem);
c = usb_minors[minor];
- if (!c || !(new_fops = fops_get(c))) {
- spin_unlock(&minor_lock);
- return err;
- }
- spin_unlock(&minor_lock);
+ if (!c || !(new_fops = fops_get(c)))
+ goto done;
old_fops = file->f_op;
file->f_op = new_fops;
file->f_op = fops_get(old_fops);
}
fops_put(old_fops);
+ done:
+ up_read(&minor_rwsem);
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;
}
- devfs_mk_dir("usb");
+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);
-out:
return error;
}
void usb_major_cleanup(void)
{
- class_destroy(usb_class);
- devfs_remove("usb");
unregister_chrdev(USB_MAJOR, "usb");
}
* enabled, the minor number will be based on the next available free minor,
* starting at the class_driver->minor_base.
*
- * This function also creates the devfs file for the usb device, if devfs
- * is enabled, and creates a usb class device in the sysfs tree.
+ * This function also creates a usb class device in the sysfs tree.
*
* usb_deregister_dev() must be called when the driver is done with
* the minor numbers given out by this function.
if (class_driver->fops == NULL)
goto exit;
- spin_lock (&minor_lock);
+ down_write(&minor_rwsem);
for (minor = minor_base; minor < MAX_USB_MINORS; ++minor) {
if (usb_minors[minor])
continue;
retval = 0;
break;
}
- spin_unlock (&minor_lock);
+ up_write(&minor_rwsem);
if (retval)
goto exit;
- intf->minor = minor;
+ retval = init_usb_class();
+ if (retval)
+ goto exit;
- /* handle the devfs registration */
- snprintf(name, BUS_ID_SIZE, class_driver->name, minor - minor_base);
- devfs_mk_cdev(MKDEV(USB_MAJOR, minor), class_driver->mode, name);
+ intf->minor = minor;
/* create a usb class device for this usb interface */
+ snprintf(name, BUS_ID_SIZE, class_driver->name, minor - minor_base);
temp = strrchr(name, '/');
if (temp && (temp[1] != 0x00))
++temp;
else
temp = name;
- intf->class_dev = class_device_create(usb_class, NULL,
- MKDEV(USB_MAJOR, minor),
- &intf->dev, "%s", temp);
- if (IS_ERR(intf->class_dev)) {
- spin_lock (&minor_lock);
+ intf->usb_dev = device_create(usb_class->class, &intf->dev,
+ MKDEV(USB_MAJOR, minor), "%s", temp);
+ if (IS_ERR(intf->usb_dev)) {
+ down_write(&minor_rwsem);
usb_minors[intf->minor] = NULL;
- spin_unlock (&minor_lock);
- devfs_remove (name);
- retval = PTR_ERR(intf->class_dev);
+ up_write(&minor_rwsem);
+ retval = PTR_ERR(intf->usb_dev);
}
exit:
return retval;
* call to usb_register_dev() (usually when the device is disconnected
* from the system.)
*
- * This function also cleans up the devfs file for the usb device, if devfs
- * is enabled, and removes the usb class device from the sysfs tree.
- *
+ * This function also removes the usb class device from the sysfs tree.
+ *
* This should be called by all drivers that use the USB major number.
*/
void usb_deregister_dev(struct usb_interface *intf,
dbg ("removing %d minor", intf->minor);
- spin_lock (&minor_lock);
+ down_write(&minor_rwsem);
usb_minors[intf->minor] = NULL;
- spin_unlock (&minor_lock);
+ up_write(&minor_rwsem);
snprintf(name, BUS_ID_SIZE, class_driver->name, intf->minor - minor_base);
- devfs_remove (name);
- class_device_destroy(usb_class, MKDEV(USB_MAJOR, intf->minor));
- intf->class_dev = NULL;
+ device_destroy(usb_class->class, MKDEV(USB_MAJOR, intf->minor));
+ intf->usb_dev = NULL;
intf->minor = -1;
+ destroy_usb_class();
}
EXPORT_SYMBOL(usb_deregister_dev);
-
-
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff