mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-13 21:46:53 +07:00
626f090c5c
When building the htmldocs (in verbose mode), scripts/kernel-doc reports the following type of warnings: Warning(drivers/usb/core/usb.c:76): No description found for return value of 'usb_find_alt_setting' Fix them by: - adding some missing descriptions of return values - using "Return" sections for those descriptions Signed-off-by: Yacine Belkadi <yacine.belkadi.1@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
254 lines
6.2 KiB
C
254 lines
6.2 KiB
C
/*
|
|
* 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
|
|
*
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/rwsem.h>
|
|
#include <linux/slab.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 minor = iminor(inode);
|
|
const struct file_operations *c;
|
|
int err = -ENODEV;
|
|
const struct file_operations *old_fops, *new_fops = NULL;
|
|
|
|
down_read(&minor_rwsem);
|
|
c = usb_minors[minor];
|
|
|
|
if (!c || !(new_fops = fops_get(c)))
|
|
goto done;
|
|
|
|
old_fops = file->f_op;
|
|
file->f_op = new_fops;
|
|
/* Curiouser and curiouser... NULL ->open() as "no device" ? */
|
|
if (file->f_op->open)
|
|
err = file->f_op->open(inode,file);
|
|
if (err) {
|
|
fops_put(file->f_op);
|
|
file->f_op = fops_get(old_fops);
|
|
}
|
|
fops_put(old_fops);
|
|
done:
|
|
up_read(&minor_rwsem);
|
|
return err;
|
|
}
|
|
|
|
static const struct file_operations usb_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = usb_open,
|
|
.llseek = noop_llseek,
|
|
};
|
|
|
|
static struct usb_class {
|
|
struct kref kref;
|
|
struct class *class;
|
|
} *usb_class;
|
|
|
|
static char *usb_devnode(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);
|
|
}
|
|
|
|
static int init_usb_class(void)
|
|
{
|
|
int result = 0;
|
|
|
|
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;
|
|
}
|
|
|
|
kref_init(&usb_class->kref);
|
|
usb_class->class = class_create(THIS_MODULE, "usbmisc");
|
|
if (IS_ERR(usb_class->class)) {
|
|
result = PTR_ERR(usb_class->class);
|
|
printk(KERN_ERR "class_create failed for usb devices\n");
|
|
kfree(usb_class);
|
|
usb_class = NULL;
|
|
goto exit;
|
|
}
|
|
usb_class->class->devnode = usb_devnode;
|
|
|
|
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)
|
|
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;
|
|
int minor_base = class_driver->minor_base;
|
|
int minor;
|
|
char name[20];
|
|
char *temp;
|
|
|
|
#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;
|
|
|
|
retval = init_usb_class();
|
|
if (retval)
|
|
return retval;
|
|
|
|
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;
|
|
}
|
|
up_write(&minor_rwsem);
|
|
if (intf->minor < 0)
|
|
return -EXFULL;
|
|
|
|
/* create a usb class device for this usb interface */
|
|
snprintf(name, sizeof(name), class_driver->name, minor - minor_base);
|
|
temp = strrchr(name, '/');
|
|
if (temp && (temp[1] != '\0'))
|
|
++temp;
|
|
else
|
|
temp = name;
|
|
intf->usb_dev = device_create(usb_class->class, &intf->dev,
|
|
MKDEV(USB_MAJOR, minor), class_driver,
|
|
"%s", temp);
|
|
if (IS_ERR(intf->usb_dev)) {
|
|
down_write(&minor_rwsem);
|
|
usb_minors[minor] = NULL;
|
|
intf->minor = -1;
|
|
up_write(&minor_rwsem);
|
|
retval = PTR_ERR(intf->usb_dev);
|
|
}
|
|
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);
|
|
|
|
down_write(&minor_rwsem);
|
|
usb_minors[intf->minor] = NULL;
|
|
up_write(&minor_rwsem);
|
|
|
|
device_destroy(usb_class->class, MKDEV(USB_MAJOR, intf->minor));
|
|
intf->usb_dev = NULL;
|
|
intf->minor = -1;
|
|
destroy_usb_class();
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_deregister_dev);
|