📄 driver.c
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/* * drivers/usb/driver.c - most of the driver model stuff for usb * * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de> * * based on drivers/usb/usb.c which had the following copyrights: * (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 2000-2004 * (C) Copyright Yggdrasil Computing, Inc. 2000 * (usb_device_id matching changes by Adam J. Richter) * (C) Copyright Greg Kroah-Hartman 2002-2003 * * NOTE! This is not actually a driver at all, rather this is * just a collection of helper routines that implement the * matching, probing, releasing, suspending and resuming for * real drivers. * */#include <linux/device.h>#include <linux/usb.h>#include <linux/workqueue.h>#include "hcd.h"#include "usb.h"/* * Adds a new dynamic USBdevice ID to this driver, * and cause the driver to probe for all devices again. */ssize_t usb_store_new_id(struct usb_dynids *dynids, struct device_driver *driver, const char *buf, size_t count){ struct usb_dynid *dynid; u32 idVendor = 0; u32 idProduct = 0; int fields = 0; int retval = 0; fields = sscanf(buf, "%x %x", &idVendor, &idProduct); if (fields < 2) return -EINVAL; dynid = kzalloc(sizeof(*dynid), GFP_KERNEL); if (!dynid) return -ENOMEM; INIT_LIST_HEAD(&dynid->node); dynid->id.idVendor = idVendor; dynid->id.idProduct = idProduct; dynid->id.match_flags = USB_DEVICE_ID_MATCH_DEVICE; spin_lock(&dynids->lock); list_add_tail(&dynid->node, &dynids->list); spin_unlock(&dynids->lock); if (get_driver(driver)) { retval = driver_attach(driver); put_driver(driver); } if (retval) return retval; return count;}EXPORT_SYMBOL_GPL(usb_store_new_id);static ssize_t store_new_id(struct device_driver *driver, const char *buf, size_t count){ struct usb_driver *usb_drv = to_usb_driver(driver); return usb_store_new_id(&usb_drv->dynids, driver, buf, count);}static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id);static int usb_create_newid_file(struct usb_driver *usb_drv){ int error = 0; if (usb_drv->no_dynamic_id) goto exit; if (usb_drv->probe != NULL) error = sysfs_create_file(&usb_drv->drvwrap.driver.kobj, &driver_attr_new_id.attr);exit: return error;}static void usb_remove_newid_file(struct usb_driver *usb_drv){ if (usb_drv->no_dynamic_id) return; if (usb_drv->probe != NULL) sysfs_remove_file(&usb_drv->drvwrap.driver.kobj, &driver_attr_new_id.attr);}static void usb_free_dynids(struct usb_driver *usb_drv){ struct usb_dynid *dynid, *n; spin_lock(&usb_drv->dynids.lock); list_for_each_entry_safe(dynid, n, &usb_drv->dynids.list, node) { list_del(&dynid->node); kfree(dynid); } spin_unlock(&usb_drv->dynids.lock);}static const struct usb_device_id *usb_match_dynamic_id(struct usb_interface *intf, struct usb_driver *drv){ struct usb_dynid *dynid; spin_lock(&drv->dynids.lock); list_for_each_entry(dynid, &drv->dynids.list, node) { if (usb_match_one_id(intf, &dynid->id)) { spin_unlock(&drv->dynids.lock); return &dynid->id; } } spin_unlock(&drv->dynids.lock); return NULL;}/* called from driver core with dev locked */static int usb_probe_device(struct device *dev){ struct usb_device_driver *udriver = to_usb_device_driver(dev->driver); struct usb_device *udev; int error = -ENODEV; dev_dbg(dev, "%s\n", __FUNCTION__); if (!is_usb_device(dev)) /* Sanity check */ return error; udev = to_usb_device(dev); /* TODO: Add real matching code */ /* The device should always appear to be in use * unless the driver suports autosuspend. */ udev->pm_usage_cnt = !(udriver->supports_autosuspend); error = udriver->probe(udev); return error;}/* called from driver core with dev locked */static int usb_unbind_device(struct device *dev){ struct usb_device_driver *udriver = to_usb_device_driver(dev->driver); udriver->disconnect(to_usb_device(dev)); return 0;}/* called from driver core with dev locked */static int usb_probe_interface(struct device *dev){ struct usb_driver *driver = to_usb_driver(dev->driver); struct usb_interface *intf; struct usb_device *udev; const struct usb_device_id *id; int error = -ENODEV; dev_dbg(dev, "%s\n", __FUNCTION__); if (is_usb_device(dev)) /* Sanity check */ return error; intf = to_usb_interface(dev); udev = interface_to_usbdev(intf); id = usb_match_id(intf, driver->id_table); if (!id) id = usb_match_dynamic_id(intf, driver); if (id) { dev_dbg(dev, "%s - got id\n", __FUNCTION__); error = usb_autoresume_device(udev); if (error) return error; /* Interface "power state" doesn't correspond to any hardware * state whatsoever. We use it to record when it's bound to * a driver that may start I/0: it's not frozen/quiesced. */ mark_active(intf); intf->condition = USB_INTERFACE_BINDING; /* The interface should always appear to be in use * unless the driver suports autosuspend. */ intf->pm_usage_cnt = !(driver->supports_autosuspend); error = driver->probe(intf, id); if (error) { mark_quiesced(intf); intf->needs_remote_wakeup = 0; intf->condition = USB_INTERFACE_UNBOUND; } else intf->condition = USB_INTERFACE_BOUND; usb_autosuspend_device(udev); } return error;}/* called from driver core with dev locked */static int usb_unbind_interface(struct device *dev){ struct usb_driver *driver = to_usb_driver(dev->driver); struct usb_interface *intf = to_usb_interface(dev); struct usb_device *udev; int error; intf->condition = USB_INTERFACE_UNBINDING; /* Autoresume for set_interface call below */ udev = interface_to_usbdev(intf); error = usb_autoresume_device(udev); /* release all urbs for this interface */ usb_disable_interface(interface_to_usbdev(intf), intf); driver->disconnect(intf); /* reset other interface state */ usb_set_interface(interface_to_usbdev(intf), intf->altsetting[0].desc.bInterfaceNumber, 0); usb_set_intfdata(intf, NULL); intf->condition = USB_INTERFACE_UNBOUND; mark_quiesced(intf); intf->needs_remote_wakeup = 0; if (!error) usb_autosuspend_device(udev); return 0;}/** * usb_driver_claim_interface - bind a driver to an interface * @driver: the driver to be bound * @iface: the interface to which it will be bound; must be in the * usb device's active configuration * @priv: driver data associated with that interface * * This is used by usb device drivers that need to claim more than one * interface on a device when probing (audio and acm are current examples). * No device driver should directly modify internal usb_interface or * usb_device structure members. * * Few drivers should need to use this routine, since the most natural * way to bind to an interface is to return the private data from * the driver's probe() method. * * Callers must own the device lock, so driver probe() entries don't need * extra locking, but other call contexts may need to explicitly claim that * lock. */int usb_driver_claim_interface(struct usb_driver *driver, struct usb_interface *iface, void* priv){ struct device *dev = &iface->dev; struct usb_device *udev = interface_to_usbdev(iface); int retval = 0; if (dev->driver) return -EBUSY; dev->driver = &driver->drvwrap.driver; usb_set_intfdata(iface, priv); usb_pm_lock(udev); iface->condition = USB_INTERFACE_BOUND; mark_active(iface); iface->pm_usage_cnt = !(driver->supports_autosuspend); usb_pm_unlock(udev); /* if interface was already added, bind now; else let * the future device_add() bind it, bypassing probe() */ if (device_is_registered(dev)) retval = device_bind_driver(dev); return retval;}EXPORT_SYMBOL(usb_driver_claim_interface);/** * usb_driver_release_interface - unbind a driver from an interface * @driver: the driver to be unbound * @iface: the interface from which it will be unbound * * This can be used by drivers to release an interface without waiting * for their disconnect() methods to be called. In typical cases this * also causes the driver disconnect() method to be called. * * This call is synchronous, and may not be used in an interrupt context. * Callers must own the device lock, so driver disconnect() entries don't * need extra locking, but other call contexts may need to explicitly claim * that lock. */void usb_driver_release_interface(struct usb_driver *driver, struct usb_interface *iface){ struct device *dev = &iface->dev; struct usb_device *udev = interface_to_usbdev(iface); /* this should never happen, don't release something that's not ours */ if (!dev->driver || dev->driver != &driver->drvwrap.driver) return; /* don't release from within disconnect() */ if (iface->condition != USB_INTERFACE_BOUND) return; /* don't release if the interface hasn't been added yet */ if (device_is_registered(dev)) { iface->condition = USB_INTERFACE_UNBINDING; device_release_driver(dev); } dev->driver = NULL; usb_set_intfdata(iface, NULL); usb_pm_lock(udev); iface->condition = USB_INTERFACE_UNBOUND; mark_quiesced(iface); iface->needs_remote_wakeup = 0; usb_pm_unlock(udev);}EXPORT_SYMBOL(usb_driver_release_interface);/* returns 0 if no match, 1 if match */int usb_match_device(struct usb_device *dev, const struct usb_device_id *id){ if ((id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) && id->idVendor != le16_to_cpu(dev->descriptor.idVendor)) return 0; if ((id->match_flags & USB_DEVICE_ID_MATCH_PRODUCT) && id->idProduct != le16_to_cpu(dev->descriptor.idProduct)) return 0; /* No need to test id->bcdDevice_lo != 0, since 0 is never greater than any unsigned number. */ if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_LO) && (id->bcdDevice_lo > le16_to_cpu(dev->descriptor.bcdDevice))) return 0; if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_HI) && (id->bcdDevice_hi < le16_to_cpu(dev->descriptor.bcdDevice))) return 0; if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_CLASS) && (id->bDeviceClass != dev->descriptor.bDeviceClass)) return 0; if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_SUBCLASS) && (id->bDeviceSubClass!= dev->descriptor.bDeviceSubClass)) return 0; if ((id->match_flags & USB_DEVICE_ID_MATCH_DEV_PROTOCOL) && (id->bDeviceProtocol != dev->descriptor.bDeviceProtocol)) return 0; return 1;}/* returns 0 if no match, 1 if match */int usb_match_one_id(struct usb_interface *interface, const struct usb_device_id *id){ struct usb_host_interface *intf; struct usb_device *dev; /* proc_connectinfo in devio.c may call us with id == NULL. */ if (id == NULL) return 0; intf = interface->cur_altsetting; dev = interface_to_usbdev(interface); if (!usb_match_device(dev, id)) return 0; /* The interface class, subclass, and protocol should never be * checked for a match if the device class is Vendor Specific, * unless the match record specifies the Vendor ID. */ if (dev->descriptor.bDeviceClass == USB_CLASS_VENDOR_SPEC && !(id->match_flags & USB_DEVICE_ID_MATCH_VENDOR) && (id->match_flags & (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS | USB_DEVICE_ID_MATCH_INT_PROTOCOL))) return 0; if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_CLASS) && (id->bInterfaceClass != intf->desc.bInterfaceClass)) return 0; if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_SUBCLASS) && (id->bInterfaceSubClass != intf->desc.bInterfaceSubClass)) return 0; if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_PROTOCOL) && (id->bInterfaceProtocol != intf->desc.bInterfaceProtocol)) return 0; return 1;}EXPORT_SYMBOL_GPL(usb_match_one_id);/** * usb_match_id - find first usb_device_id matching device or interface * @interface: the interface of interest * @id: array of usb_device_id structures, terminated by zero entry * * usb_match_id searches an array of usb_device_id's and returns * the first one matching the device or interface, or null. * This is used when binding (or rebinding) a driver to an interface. * Most USB device drivers will use this indirectly, through the usb core, * but some layered driver frameworks use it directly. * These device tables are exported with MODULE_DEVICE_TABLE, through * modutils, to support the driver loading functionality of USB hotplugging. * * What Matches: * * The "match_flags" element in a usb_device_id controls which * members are used. If the corresponding bit is set, the * value in the device_id must match its corresponding member * in the device or interface descriptor, or else the device_id * does not match. * * "driver_info" is normally used only by device drivers, * but you can create a wildcard "matches anything" usb_device_id * as a driver's "modules.usbmap" entry if you provide an id with * only a nonzero "driver_info" field. If you do this, the USB device * driver's probe() routine should use additional intelligence to * decide whether to bind to the specified interface. * * What Makes Good usb_device_id Tables: * * The match algorithm is very simple, so that intelligence in * driver selection must come from smart driver id records. * Unless you have good reasons to use another selection policy, * provide match elements only in related groups, and order match * specifiers from specific to general. Use the macros provided * for that purpose if you can. * * The most specific match specifiers use device descriptor * data. These are commonly used with product-specific matches; * the USB_DEVICE macro lets you provide vendor and product IDs, * and you can also match against ranges of product revisions. * These are widely used for devices with application or vendor * specific bDeviceClass values. * * Matches based on device class/subclass/protocol specifications * are slightly more general; use the USB_DEVICE_INFO macro, or * its siblings. These are used with single-function devices * where bDeviceClass doesn't specify that each interface has * its own class. * * Matches based on interface class/subclass/protocol are the * most general; they let drivers bind to any interface on a * multiple-function device. Use the USB_INTERFACE_INFO * macro, or its siblings, to match class-per-interface style * devices (as recorded in bInterfaceClass). * * Note that an entry created by USB_INTERFACE_INFO won't match * any interface if the device class is set to Vendor-Specific. * This is deliberate; according to the USB spec the meanings of * the interface class/subclass/protocol for these devices are also * vendor-specific, and hence matching against a standard product * class wouldn't work anyway. If you really want to use an * interface-based match for such a device, create a match record
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