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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/usb/core/file.c | |
download | op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/usb/core/file.c')
-rw-r--r-- | drivers/usb/core/file.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/drivers/usb/core/file.c b/drivers/usb/core/file.c new file mode 100644 index 0000000..80ce964 --- /dev/null +++ b/drivers/usb/core/file.c @@ -0,0 +1,227 @@ +/* + * drivers/usb/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/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/usb.h> + +#define MAX_USB_MINORS 256 +static 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; + int err = -ENODEV; + struct file_operations *old_fops, *new_fops = NULL; + + spin_lock (&minor_lock); + c = usb_minors[minor]; + + if (!c || !(new_fops = fops_get(c))) { + spin_unlock(&minor_lock); + return err; + } + spin_unlock(&minor_lock); + + 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); + return err; +} + +static struct file_operations usb_fops = { + .owner = THIS_MODULE, + .open = usb_open, +}; + +static struct class_simple *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); + goto out; + } + + usb_class = class_simple_create(THIS_MODULE, "usb"); + if (IS_ERR(usb_class)) { + err("class_simple_create failed for usb devices"); + unregister_chrdev(USB_MAJOR, "usb"); + goto out; + } + + devfs_mk_dir("usb"); + +out: + return error; +} + +void usb_major_cleanup(void) +{ + class_simple_destroy(usb_class); + devfs_remove("usb"); + 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 the devfs file for the usb device, if devfs + * is enabled, and 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. + * + * Returns -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 = -EINVAL; + int minor_base = class_driver->minor_base; + int minor = 0; + char name[BUS_ID_SIZE]; + 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 + intf->minor = -1; + + dbg ("looking for a minor, starting at %d", minor_base); + + if (class_driver->fops == NULL) + goto exit; + + spin_lock (&minor_lock); + for (minor = minor_base; minor < MAX_USB_MINORS; ++minor) { + if (usb_minors[minor]) + continue; + + usb_minors[minor] = class_driver->fops; + + retval = 0; + break; + } + spin_unlock (&minor_lock); + + if (retval) + goto exit; + + intf->minor = minor; + + /* 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); + + /* create a usb class device for this usb interface */ + temp = strrchr(name, '/'); + if (temp && (temp[1] != 0x00)) + ++temp; + else + temp = name; + intf->class_dev = class_simple_device_add(usb_class, MKDEV(USB_MAJOR, minor), &intf->dev, "%s", temp); + if (IS_ERR(intf->class_dev)) { + spin_lock (&minor_lock); + usb_minors[intf->minor] = NULL; + spin_unlock (&minor_lock); + devfs_remove (name); + retval = PTR_ERR(intf->class_dev); + } +exit: + return retval; +} +EXPORT_SYMBOL(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 cleans up the devfs file for the usb device, if devfs + * is enabled, and 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) +{ + int minor_base = class_driver->minor_base; + char name[BUS_ID_SIZE]; + +#ifdef CONFIG_USB_DYNAMIC_MINORS + minor_base = 0; +#endif + + if (intf->minor == -1) + return; + + dbg ("removing %d minor", intf->minor); + + spin_lock (&minor_lock); + usb_minors[intf->minor] = NULL; + spin_unlock (&minor_lock); + + snprintf(name, BUS_ID_SIZE, class_driver->name, intf->minor - minor_base); + devfs_remove (name); + class_simple_device_remove(MKDEV(USB_MAJOR, intf->minor)); + intf->class_dev = NULL; + intf->minor = -1; +} +EXPORT_SYMBOL(usb_deregister_dev); + + |