Contributors: 15
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Greg Kroah-Hartman |
355 |
57.17% |
21 |
37.50% |
| Linus Torvalds (pre-git) |
82 |
13.20% |
16 |
28.57% |
| Alan Stern |
60 |
9.66% |
3 |
5.36% |
| Kay Sievers |
59 |
9.50% |
3 |
5.36% |
| Ivan Orlov |
16 |
2.58% |
1 |
1.79% |
| Al Viro |
13 |
2.09% |
2 |
3.57% |
| Luiz Fernando N. Capitulino |
12 |
1.93% |
2 |
3.57% |
| Andy Shevchenko |
7 |
1.13% |
1 |
1.79% |
| Arnd Bergmann |
5 |
0.81% |
1 |
1.79% |
| Rusty Russell |
4 |
0.64% |
1 |
1.79% |
| Thomas Gleixner |
3 |
0.48% |
1 |
1.79% |
| Arjan van de Ven |
2 |
0.32% |
1 |
1.79% |
| Linus Torvalds |
1 |
0.16% |
1 |
1.79% |
| Yacine Belkadi |
1 |
0.16% |
1 |
1.79% |
| Matthias Beyer |
1 |
0.16% |
1 |
1.79% |
| Total |
621 |
|
56 |
|
// SPDX-License-Identifier: GPL-2.0
/*
* drivers/usb/core/file.c
*
* (C) Copyright Linus Torvalds 1999
* (C) Copyright Johannes Erdfelt 1999-2001
* (C) Copyright Andreas Gal 1999
* (C) Copyright Gregory P. Smith 1999
* (C) Copyright Deti Fliegl 1999 (new USB architecture)
* (C) Copyright Randy Dunlap 2000
* (C) Copyright David Brownell 2000-2001 (kernel hotplug, usb_device_id,
* more docs, etc)
* (C) Copyright Yggdrasil Computing, Inc. 2000
* (usb_device_id matching changes by Adam J. Richter)
* (C) Copyright Greg Kroah-Hartman 2002-2003
*
* Released under the GPLv2 only.
*/
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/usb.h>
#include "usb.h"
#define MAX_USB_MINORS 256
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 err = -ENODEV;
const struct file_operations *new_fops;
down_read(&minor_rwsem);
new_fops = fops_get(usb_minors[iminor(inode)]);
if (!new_fops)
goto done;
replace_fops(file, new_fops);
/* Curiouser and curiouser... NULL ->open() as "no device" ? */
if (file->f_op->open)
err = file->f_op->open(inode, file);
done:
up_read(&minor_rwsem);
return err;
}
static const struct file_operations usb_fops = {
.owner = THIS_MODULE,
.open = usb_open,
.llseek = noop_llseek,
};
static char *usb_devnode(const struct device *dev, umode_t *mode)
{
struct usb_class_driver *drv;
drv = dev_get_drvdata(dev);
if (!drv || !drv->devnode)
return NULL;
return drv->devnode(dev, mode);
}
const struct class usbmisc_class = {
.name = "usbmisc",
.devnode = usb_devnode,
};
int usb_major_init(void)
{
int error;
error = register_chrdev(USB_MAJOR, "usb", &usb_fops);
if (error)
printk(KERN_ERR "Unable to get major %d for usb devices\n",
USB_MAJOR);
return error;
}
void usb_major_cleanup(void)
{
unregister_chrdev(USB_MAJOR, "usb");
}
/**
* usb_register_dev - register a USB device, and ask for a minor number
* @intf: pointer to the usb_interface that is being registered
* @class_driver: pointer to the usb_class_driver for this device
*
* This should be called by all USB drivers that use the USB major number.
* If CONFIG_USB_DYNAMIC_MINORS is enabled, the minor number will be
* dynamically allocated out of the list of available ones. If it is not
* enabled, the minor number will be based on the next available free minor,
* starting at the class_driver->minor_base.
*
* 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.
*
* Return: -EINVAL if something bad happens with trying to register a
* device, and 0 on success.
*/
int usb_register_dev(struct usb_interface *intf,
struct usb_class_driver *class_driver)
{
int retval = 0;
int minor_base = class_driver->minor_base;
int minor;
char name[20];
#ifdef CONFIG_USB_DYNAMIC_MINORS
/*
* We don't care what the device tries to start at, we want to start
* at zero to pack the devices into the smallest available space with
* no holes in the minor range.
*/
minor_base = 0;
#endif
if (class_driver->fops == NULL)
return -EINVAL;
if (intf->minor >= 0)
return -EADDRINUSE;
dev_dbg(&intf->dev, "looking for a minor, starting at %d\n", minor_base);
down_write(&minor_rwsem);
for (minor = minor_base; minor < MAX_USB_MINORS; ++minor) {
if (usb_minors[minor])
continue;
usb_minors[minor] = class_driver->fops;
intf->minor = minor;
break;
}
if (intf->minor < 0) {
up_write(&minor_rwsem);
return -EXFULL;
}
/* create a usb class device for this usb interface */
snprintf(name, sizeof(name), class_driver->name, minor - minor_base);
intf->usb_dev = device_create(&usbmisc_class, &intf->dev,
MKDEV(USB_MAJOR, minor), class_driver,
"%s", kbasename(name));
if (IS_ERR(intf->usb_dev)) {
usb_minors[minor] = NULL;
intf->minor = -1;
retval = PTR_ERR(intf->usb_dev);
}
up_write(&minor_rwsem);
return retval;
}
EXPORT_SYMBOL_GPL(usb_register_dev);
/**
* usb_deregister_dev - deregister a USB device's dynamic minor.
* @intf: pointer to the usb_interface that is being deregistered
* @class_driver: pointer to the usb_class_driver for this device
*
* Used in conjunction with usb_register_dev(). This function is called
* when the USB driver is finished with the minor numbers gotten from a
* call to usb_register_dev() (usually when the device is disconnected
* from the system.)
*
* 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,
struct usb_class_driver *class_driver)
{
if (intf->minor == -1)
return;
dev_dbg(&intf->dev, "removing %d minor\n", intf->minor);
device_destroy(&usbmisc_class, MKDEV(USB_MAJOR, intf->minor));
down_write(&minor_rwsem);
usb_minors[intf->minor] = NULL;
up_write(&minor_rwsem);
intf->usb_dev = NULL;
intf->minor = -1;
}
EXPORT_SYMBOL_GPL(usb_deregister_dev);