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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 02:20:36 +0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 02:20:36 +0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/usb/core/file.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz
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.c227
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 000000000000..80ce9644d0ee
--- /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);
+
+