/* * drivers/usb/driver.c - most of the driver model stuff for usb * * (C) Copyright 2005 Greg Kroah-Hartman * * 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 #include #include #include "hcd.h" #include "usb.h" static int usb_match_one_id(struct usb_interface *interface, const struct usb_device_id *id); struct usb_dynid { struct list_head node; struct usb_device_id id; }; #ifdef CONFIG_HOTPLUG /* * Adds a new dynamic USBdevice ID to this driver, * and cause the driver to probe for all devices again. */ 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); 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(&usb_drv->dynids.lock); list_add_tail(&usb_drv->dynids.list, &dynid->node); spin_unlock(&usb_drv->dynids.lock); if (get_driver(driver)) { retval = driver_attach(driver); put_driver(driver); } if (retval) return retval; return 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); } #else static inline int usb_create_newid_file(struct usb_driver *usb_drv) { return 0; } static void usb_remove_newid_file(struct usb_driver *usb_drv) { } static inline void usb_free_dynids(struct usb_driver *usb_drv) { } #endif 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, 1); 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, 1); } 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, 1); /* 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, 1); 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 and the driver model's usb_bus_type.subsys * writelock. So driver probe() entries don't need extra locking, * but other call contexts may need to explicitly claim those locks. */ 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 and the driver model's usb_bus_type.subsys * writelock. So driver disconnect() entries don't need extra locking, * but other call contexts may need to explicitly claim those locks. */ 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 */ static 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 ((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; /* 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; } /** * 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 * that also specifies the vendor ID. (Unforunately there isn't a * standard macro for creating records like this.) * * Within those groups, remember that not all combinations are * meaningful. For example, don't give a product version range * without vendor and product IDs; or specify a protocol without * its associated class and subclass. */ const struct usb_device_id *usb_match_id(struct usb_interface *interface, const struct usb_device_id *id) { /* proc_connectinfo in devio.c may call us with id == NULL. */ if (id == NULL) return NULL; /* It is important to check that id->driver_info is nonzero, since an entry that is all zeroes except for a nonzero id->driver_info is the way to create an entry that indicates that the driver want to examine every device and interface. */ for (; id->idVendor || id->bDeviceClass || id->bInterfaceClass || id->driver_info; id++) { if (usb_match_one_id(interface, id)) return id; } return NULL; } EXPORT_SYMBOL_GPL_FUTURE(usb_match_id); int usb_device_match(struct device *dev, struct device_driver *drv) { /* devices and interfaces are handled separately */ if (is_usb_device(dev)) { /* interface drivers never match devices */ if (!is_usb_device_driver(drv)) return 0; /* TODO: Add real matching code */ return 1; } else { struct usb_interface *intf; struct usb_driver *usb_drv; const struct usb_device_id *id; /* device drivers never match interfaces */ if (is_usb_device_driver(drv)) return 0; intf = to_usb_interface(dev); usb_drv = to_usb_driver(drv); id = usb_match_id(intf, usb_drv->id_table); if (id) return 1; id = usb_match_dynamic_id(intf, usb_drv); if (id) return 1; } return 0; } #ifdef CONFIG_HOTPLUG /* * This sends an uevent to userspace, typically helping to load driver * or other modules, configure the device, and more. Drivers can provide * a MODULE_DEVICE_TABLE to help with module loading subtasks. * * We're called either from khubd (the typical case) or from root hub * (init, kapmd, modprobe, rmmod, etc), but the agents need to handle * delays in event delivery. Use sysfs (and DEVPATH) to make sure the * device (and this configuration!) are still present. */ static int usb_uevent(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size) { struct usb_interface *intf; struct usb_device *usb_dev; struct usb_host_interface *alt; int i = 0; int length = 0; if (!dev) return -ENODEV; /* driver is often null here; dev_dbg() would oops */ pr_debug ("usb %s: uevent\n", dev->bus_id); if (is_usb_device(dev)) { usb_dev = to_usb_device(dev); alt = NULL; } else { intf = to_usb_interface(dev); usb_dev = interface_to_usbdev(intf); alt = intf->cur_altsetting; } if (usb_dev->devnum < 0) { pr_debug ("usb %s: already deleted?\n", dev->bus_id); return -ENODEV; } if (!usb_dev->bus) { pr_debug ("usb %s: bus removed?\n", dev->bus_id); return -ENODEV; } #ifdef CONFIG_USB_DEVICEFS /* If this is available, userspace programs can directly read * all the device descriptors we don't tell them about. Or * even act as usermode drivers. * * FIXME reduce hardwired intelligence here */ if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "DEVICE=/proc/bus/usb/%03d/%03d", usb_dev->bus->busnum, usb_dev->devnum)) return -ENOMEM; #endif /* per-device configurations are common */ if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "PRODUCT=%x/%x/%x", le16_to_cpu(usb_dev->descriptor.idVendor), le16_to_cpu(usb_dev->descriptor.idProduct), le16_to_cpu(usb_dev->descriptor.bcdDevice))) return -ENOMEM; /* class-based driver binding models */ if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "TYPE=%d/%d/%d", usb_dev->descriptor.bDeviceClass, usb_dev->descriptor.bDeviceSubClass, usb_dev->descriptor.bDeviceProtocol)) return -ENOMEM; if (!is_usb_device(dev)) { if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "INTERFACE=%d/%d/%d", alt->desc.bInterfaceClass, alt->desc.bInterfaceSubClass, alt->desc.bInterfaceProtocol)) return -ENOMEM; if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, "MODALIAS=usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02X", le16_to_cpu(usb_dev->descriptor.idVendor), le16_to_cpu(usb_dev->descriptor.idProduct), le16_to_cpu(usb_dev->descriptor.bcdDevice), usb_dev->descriptor.bDeviceClass, usb_dev->descriptor.bDeviceSubClass, usb_dev->descriptor.bDeviceProtocol, alt->desc.bInterfaceClass, alt->desc.bInterfaceSubClass, alt->desc.bInterfaceProtocol)) return -ENOMEM; } envp[i] = NULL; return 0; } #else static int usb_uevent(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size) { return -ENODEV; } #endif /* CONFIG_HOTPLUG */ /** * usb_register_device_driver - register a USB device (not interface) driver * @new_udriver: USB operations for the device driver * @owner: module owner of this driver. * * Registers a USB device driver with the USB core. The list of * unattached devices will be rescanned whenever a new driver is * added, allowing the new driver to attach to any recognized devices. * Returns a negative error code on failure and 0 on success. */ int usb_register_device_driver(struct usb_device_driver *new_udriver, struct module *owner) { int retval = 0; if (usb_disabled()) return -ENODEV; new_udriver->drvwrap.for_devices = 1; new_udriver->drvwrap.driver.name = (char *) new_udriver->name; new_udriver->drvwrap.driver.bus = &usb_bus_type; new_udriver->drvwrap.driver.probe = usb_probe_device; new_udriver->drvwrap.driver.remove = usb_unbind_device; new_udriver->drvwrap.driver.owner = owner; retval = driver_register(&new_udriver->drvwrap.driver); if (!retval) { pr_info("%s: registered new device driver %s\n", usbcore_name, new_udriver->name); usbfs_update_special(); } else { printk(KERN_ERR "%s: error %d registering device " " driver %s\n", usbcore_name, retval, new_udriver->name); } return retval; } EXPORT_SYMBOL_GPL(usb_register_device_driver); /** * usb_deregister_device_driver - unregister a USB device (not interface) driver * @udriver: USB operations of the device driver to unregister * Context: must be able to sleep * * Unlinks the specified driver from the internal USB driver list. */ void usb_deregister_device_driver(struct usb_device_driver *udriver) { pr_info("%s: deregistering device driver %s\n", usbcore_name, udriver->name); driver_unregister(&udriver->drvwrap.driver); usbfs_update_special(); } EXPORT_SYMBOL_GPL(usb_deregister_device_driver); /** * usb_register_driver - register a USB interface driver * @new_driver: USB operations for the interface driver * @owner: module owner of this driver. * * Registers a USB interface driver with the USB core. The list of * unattached interfaces will be rescanned whenever a new driver is * added, allowing the new driver to attach to any recognized interfaces. * Returns a negative error code on failure and 0 on success. * * NOTE: if you want your driver to use the USB major number, you must call * usb_register_dev() to enable that functionality. This function no longer * takes care of that. */ int usb_register_driver(struct usb_driver *new_driver, struct module *owner) { int retval = 0; if (usb_disabled()) return -ENODEV; new_driver->drvwrap.for_devices = 0; new_driver->drvwrap.driver.name = (char *) new_driver->name; new_driver->drvwrap.driver.bus = &usb_bus_type; new_driver->drvwrap.driver.probe = usb_probe_interface; new_driver->drvwrap.driver.remove = usb_unbind_interface; new_driver->drvwrap.driver.owner = owner; spin_lock_init(&new_driver->dynids.lock); INIT_LIST_HEAD(&new_driver->dynids.list); retval = driver_register(&new_driver->drvwrap.driver); if (!retval) { pr_info("%s: registered new interface driver %s\n", usbcore_name, new_driver->name); usbfs_update_special(); usb_create_newid_file(new_driver); } else { printk(KERN_ERR "%s: error %d registering interface " " driver %s\n", usbcore_name, retval, new_driver->name); } return retval; } EXPORT_SYMBOL_GPL_FUTURE(usb_register_driver); /** * usb_deregister - unregister a USB interface driver * @driver: USB operations of the interface driver to unregister * Context: must be able to sleep * * Unlinks the specified driver from the internal USB driver list. * * NOTE: If you called usb_register_dev(), you still need to call * usb_deregister_dev() to clean up your driver's allocated minor numbers, * this * call will no longer do it for you. */ void usb_deregister(struct usb_driver *driver) { pr_info("%s: deregistering interface driver %s\n", usbcore_name, driver->name); usb_remove_newid_file(driver); usb_free_dynids(driver); driver_unregister(&driver->drvwrap.driver); usbfs_update_special(); } EXPORT_SYMBOL_GPL_FUTURE(usb_deregister); #ifdef CONFIG_PM /* Caller has locked udev's pm_mutex */ static int suspend_device(struct usb_device *udev, pm_message_t msg) { struct usb_device_driver *udriver; int status = 0; if (udev->state == USB_STATE_NOTATTACHED || udev->state == USB_STATE_SUSPENDED) goto done; /* For devices that don't have a driver, we do a standard suspend. */ if (udev->dev.driver == NULL) { udev->do_remote_wakeup = 0; status = usb_port_suspend(udev); goto done; } udriver = to_usb_device_driver(udev->dev.driver); status = udriver->suspend(udev, msg); done: // dev_dbg(&udev->dev, "%s: status %d\n", __FUNCTION__, status); if (status == 0) udev->dev.power.power_state.event = msg.event; return status; } /* Caller has locked udev's pm_mutex */ static int resume_device(struct usb_device *udev) { struct usb_device_driver *udriver; int status = 0; if (udev->state == USB_STATE_NOTATTACHED || udev->state != USB_STATE_SUSPENDED) goto done; /* Can't resume it if it doesn't have a driver. */ if (udev->dev.driver == NULL) { status = -ENOTCONN; goto done; } udriver = to_usb_device_driver(udev->dev.driver); status = udriver->resume(udev); done: // dev_dbg(&udev->dev, "%s: status %d\n", __FUNCTION__, status); if (status == 0) udev->dev.power.power_state.event = PM_EVENT_ON; return status; } /* Caller has locked intf's usb_device's pm mutex */ static int suspend_interface(struct usb_interface *intf, pm_message_t msg) { struct usb_driver *driver; int status = 0; /* with no hardware, USB interfaces only use FREEZE and ON states */ if (interface_to_usbdev(intf)->state == USB_STATE_NOTATTACHED || !is_active(intf)) goto done; if (intf->condition == USB_INTERFACE_UNBOUND) /* This can't happen */ goto done; driver = to_usb_driver(intf->dev.driver); if (driver->suspend && driver->resume) { status = driver->suspend(intf, msg); if (status == 0) mark_quiesced(intf); else if (!interface_to_usbdev(intf)->auto_pm) dev_err(&intf->dev, "%s error %d\n", "suspend", status); } else { // FIXME else if there's no suspend method, disconnect... // Not possible if auto_pm is set... dev_warn(&intf->dev, "no suspend for driver %s?\n", driver->name); mark_quiesced(intf); } done: // dev_dbg(&intf->dev, "%s: status %d\n", __FUNCTION__, status); if (status == 0) intf->dev.power.power_state.event = msg.event; return status; } /* Caller has locked intf's usb_device's pm_mutex */ static int resume_interface(struct usb_interface *intf) { struct usb_driver *driver; int status = 0; if (interface_to_usbdev(intf)->state == USB_STATE_NOTATTACHED || is_active(intf)) goto done; /* Don't let autoresume interfere with unbinding */ if (intf->condition == USB_INTERFACE_UNBINDING) goto done; /* Can't resume it if it doesn't have a driver. */ if (intf->condition == USB_INTERFACE_UNBOUND) { status = -ENOTCONN; goto done; } driver = to_usb_driver(intf->dev.driver); if (driver->resume) { status = driver->resume(intf); if (status) dev_err(&intf->dev, "%s error %d\n", "resume", status); else mark_active(intf); } else { dev_warn(&intf->dev, "no resume for driver %s?\n", driver->name); mark_active(intf); } done: // dev_dbg(&intf->dev, "%s: status %d\n", __FUNCTION__, status); if (status == 0) intf->dev.power.power_state.event = PM_EVENT_ON; return status; } /* Internal routine to check whether we may autosuspend a device. */ static int autosuspend_check(struct usb_device *udev) { int i; struct usb_interface *intf; /* For autosuspend, fail fast if anything is in use. * Also fail if any interfaces require remote wakeup but it * isn't available. */ udev->do_remote_wakeup = device_may_wakeup(&udev->dev); if (udev->pm_usage_cnt > 0) return -EBUSY; if (udev->actconfig) { for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) { intf = udev->actconfig->interface[i]; if (!is_active(intf)) continue; if (intf->pm_usage_cnt > 0) return -EBUSY; if (intf->needs_remote_wakeup && !udev->do_remote_wakeup) { dev_dbg(&udev->dev, "remote wakeup needed " "for autosuspend\n"); return -EOPNOTSUPP; } } } return 0; } /** * usb_suspend_both - suspend a USB device and its interfaces * @udev: the usb_device to suspend * @msg: Power Management message describing this state transition * * This is the central routine for suspending USB devices. It calls the * suspend methods for all the interface drivers in @udev and then calls * the suspend method for @udev itself. If an error occurs at any stage, * all the interfaces which were suspended are resumed so that they remain * in the same state as the device. * * If an autosuspend is in progress (@udev->auto_pm is set), the routine * checks first to make sure that neither the device itself or any of its * active interfaces is in use (pm_usage_cnt is greater than 0). If they * are, the autosuspend fails. * * If the suspend succeeds, the routine recursively queues an autosuspend * request for @udev's parent device, thereby propagating the change up * the device tree. If all of the parent's children are now suspended, * the parent will autosuspend in turn. * * The suspend method calls are subject to mutual exclusion under control * of @udev's pm_mutex. Many of these calls are also under the protection * of @udev's device lock (including all requests originating outside the * USB subsystem), but autosuspend requests generated by a child device or * interface driver may not be. Usbcore will insure that the method calls * do not arrive during bind, unbind, or reset operations. However, drivers * must be prepared to handle suspend calls arriving at unpredictable times. * The only way to block such calls is to do an autoresume (preventing * autosuspends) while holding @udev's device lock (preventing outside * suspends). * * The caller must hold @udev->pm_mutex. * * This routine can run only in process context. */ int usb_suspend_both(struct usb_device *udev, pm_message_t msg) { int status = 0; int i = 0; struct usb_interface *intf; struct usb_device *parent = udev->parent; cancel_delayed_work(&udev->autosuspend); if (udev->state == USB_STATE_NOTATTACHED) return 0; if (udev->state == USB_STATE_SUSPENDED) return 0; udev->do_remote_wakeup = device_may_wakeup(&udev->dev); if (udev->auto_pm) { status = autosuspend_check(udev); if (status < 0) return status; } /* Suspend all the interfaces and then udev itself */ if (udev->actconfig) { for (; i < udev->actconfig->desc.bNumInterfaces; i++) { intf = udev->actconfig->interface[i]; status = suspend_interface(intf, msg); if (status != 0) break; } } if (status == 0) status = suspend_device(udev, msg); /* If the suspend failed, resume interfaces that did get suspended */ if (status != 0) { while (--i >= 0) { intf = udev->actconfig->interface[i]; resume_interface(intf); } /* If the suspend succeeded, propagate it up the tree */ } else if (parent) usb_autosuspend_device(parent, 0); // dev_dbg(&udev->dev, "%s: status %d\n", __FUNCTION__, status); return status; } /** * usb_resume_both - resume a USB device and its interfaces * @udev: the usb_device to resume * * This is the central routine for resuming USB devices. It calls the * the resume method for @udev and then calls the resume methods for all * the interface drivers in @udev. * * Before starting the resume, the routine calls itself recursively for * the parent device of @udev, thereby propagating the change up the device * tree and assuring that @udev will be able to resume. If the parent is * unable to resume successfully, the routine fails. * * The resume method calls are subject to mutual exclusion under control * of @udev's pm_mutex. Many of these calls are also under the protection * of @udev's device lock (including all requests originating outside the * USB subsystem), but autoresume requests generated by a child device or * interface driver may not be. Usbcore will insure that the method calls * do not arrive during bind, unbind, or reset operations. However, drivers * must be prepared to handle resume calls arriving at unpredictable times. * The only way to block such calls is to do an autoresume (preventing * other autoresumes) while holding @udev's device lock (preventing outside * resumes). * * The caller must hold @udev->pm_mutex. * * This routine can run only in process context. */ int usb_resume_both(struct usb_device *udev) { int status = 0; int i; struct usb_interface *intf; struct usb_device *parent = udev->parent; cancel_delayed_work(&udev->autosuspend); if (udev->state == USB_STATE_NOTATTACHED) return -ENODEV; /* Propagate the resume up the tree, if necessary */ if (udev->state == USB_STATE_SUSPENDED) { if (parent) { usb_pm_lock(parent); parent->auto_pm = 1; status = usb_resume_both(parent); } else { /* We can't progagate beyond the USB subsystem, * so if a root hub's controller is suspended * then we're stuck. */ if (udev->dev.parent->power.power_state.event != PM_EVENT_ON) status = -EHOSTUNREACH; } if (status == 0) status = resume_device(udev); if (parent) usb_pm_unlock(parent); } else { /* Needed only for setting udev->dev.power.power_state.event * and for possible debugging message. */ status = resume_device(udev); } /* Now the parent won't suspend until we are finished */ if (status == 0 && udev->actconfig) { for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) { intf = udev->actconfig->interface[i]; resume_interface(intf); } } // dev_dbg(&udev->dev, "%s: status %d\n", __FUNCTION__, status); return status; } #ifdef CONFIG_USB_SUSPEND /** * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces * @udev: the usb_device to autosuspend * @dec_usage_cnt: flag to decrement @udev's PM-usage counter * * This routine should be called when a core subsystem is finished using * @udev and wants to allow it to autosuspend. Examples would be when * @udev's device file in usbfs is closed or after a configuration change. * * @dec_usage_cnt should be 1 if the subsystem previously incremented * @udev's usage counter (such as by passing 1 to usb_autoresume_device); * otherwise it should be 0. * * If the usage counter for @udev or any of its active interfaces is greater * than 0, the autosuspend request will not be queued. (If an interface * driver does not support autosuspend then its usage counter is permanently * positive.) Likewise, if an interface driver requires remote-wakeup * capability during autosuspend but remote wakeup is disabled, the * autosuspend will fail. * * Often the caller will hold @udev's device lock, but this is not * necessary. * * This routine can run only in process context. */ void usb_autosuspend_device(struct usb_device *udev, int dec_usage_cnt) { usb_pm_lock(udev); udev->pm_usage_cnt -= dec_usage_cnt; if (autosuspend_check(udev) == 0) queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend, USB_AUTOSUSPEND_DELAY); usb_pm_unlock(udev); // dev_dbg(&udev->dev, "%s: cnt %d\n", // __FUNCTION__, udev->pm_usage_cnt); } /** * usb_autoresume_device - immediately autoresume a USB device and its interfaces * @udev: the usb_device to autoresume * @inc_usage_cnt: flag to increment @udev's PM-usage counter * * This routine should be called when a core subsystem wants to use @udev * and needs to guarantee that it is not suspended. In addition, the * caller can prevent @udev from being autosuspended subsequently. (Note * that this will not prevent suspend events originating in the PM core.) * Examples would be when @udev's device file in usbfs is opened (autosuspend * should be prevented until the file is closed) or when a remote-wakeup * request is received (later autosuspends should not be prevented). * * @inc_usage_cnt should be 1 to increment @udev's usage counter and prevent * autosuspends. This prevention will persist until the usage counter is * decremented again (such as by passing 1 to usb_autosuspend_device). * Otherwise @inc_usage_cnt should be 0 to leave the usage counter unchanged. * Regardless, if the autoresume fails then the usage counter is not * incremented. * * Often the caller will hold @udev's device lock, but this is not * necessary (and attempting it might cause deadlock). * * This routine can run only in process context. */ int usb_autoresume_device(struct usb_device *udev, int inc_usage_cnt) { int status; usb_pm_lock(udev); udev->pm_usage_cnt += inc_usage_cnt; udev->auto_pm = 1; status = usb_resume_both(udev); if (status != 0) udev->pm_usage_cnt -= inc_usage_cnt; usb_pm_unlock(udev); // dev_dbg(&udev->dev, "%s: status %d cnt %d\n", // __FUNCTION__, status, udev->pm_usage_cnt); return status; } /* Internal routine to adjust an interface's usage counter and change * its device's autosuspend state. */ static int usb_autopm_do_interface(struct usb_interface *intf, int inc_usage_cnt) { struct usb_device *udev = interface_to_usbdev(intf); int status = 0; usb_pm_lock(udev); if (intf->condition == USB_INTERFACE_UNBOUND) status = -ENODEV; else { intf->pm_usage_cnt += inc_usage_cnt; if (inc_usage_cnt >= 0 && intf->pm_usage_cnt > 0) { udev->auto_pm = 1; status = usb_resume_both(udev); if (status != 0) intf->pm_usage_cnt -= inc_usage_cnt; } else if (inc_usage_cnt <= 0 && autosuspend_check(udev) == 0) queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend, USB_AUTOSUSPEND_DELAY); } usb_pm_unlock(udev); return status; } /** * usb_autopm_put_interface - decrement a USB interface's PM-usage counter * @intf: the usb_interface whose counter should be decremented * * This routine should be called by an interface driver when it is * finished using @intf and wants to allow it to autosuspend. A typical * example would be a character-device driver when its device file is * closed. * * The routine decrements @intf's usage counter. When the counter reaches * 0, a delayed autosuspend request for @intf's device is queued. When * the delay expires, if @intf->pm_usage_cnt is still <= 0 along with all * the other usage counters for the sibling interfaces and @intf's * usb_device, the device and all its interfaces will be autosuspended. * * Note that @intf->pm_usage_cnt is owned by the interface driver. The * core will not change its value other than the increment and decrement * in usb_autopm_get_interface and usb_autopm_put_interface. The driver * may use this simple counter-oriented discipline or may set the value * any way it likes. * * If the driver has set @intf->needs_remote_wakeup then autosuspend will * take place only if the device's remote-wakeup facility is enabled. * * Suspend method calls queued by this routine can arrive at any time * while @intf is resumed and its usage counter is equal to 0. They are * not protected by the usb_device's lock but only by its pm_mutex. * Drivers must provide their own synchronization. * * This routine can run only in process context. */ void usb_autopm_put_interface(struct usb_interface *intf) { int status; status = usb_autopm_do_interface(intf, -1); // dev_dbg(&intf->dev, "%s: status %d cnt %d\n", // __FUNCTION__, status, intf->pm_usage_cnt); } EXPORT_SYMBOL_GPL(usb_autopm_put_interface); /** * usb_autopm_get_interface - increment a USB interface's PM-usage counter * @intf: the usb_interface whose counter should be incremented * * This routine should be called by an interface driver when it wants to * use @intf and needs to guarantee that it is not suspended. In addition, * the routine prevents @intf from being autosuspended subsequently. (Note * that this will not prevent suspend events originating in the PM core.) * This prevention will persist until usb_autopm_put_interface() is called * or @intf is unbound. A typical example would be a character-device * driver when its device file is opened. * * The routine increments @intf's usage counter. So long as the counter * is greater than 0, autosuspend will not be allowed for @intf or its * usb_device. When the driver is finished using @intf it should call * usb_autopm_put_interface() to decrement the usage counter and queue * a delayed autosuspend request (if the counter is <= 0). * * Note that @intf->pm_usage_cnt is owned by the interface driver. The * core will not change its value other than the increment and decrement * in usb_autopm_get_interface and usb_autopm_put_interface. The driver * may use this simple counter-oriented discipline or may set the value * any way it likes. * * Resume method calls generated by this routine can arrive at any time * while @intf is suspended. They are not protected by the usb_device's * lock but only by its pm_mutex. Drivers must provide their own * synchronization. * * This routine can run only in process context. */ int usb_autopm_get_interface(struct usb_interface *intf) { int status; status = usb_autopm_do_interface(intf, 1); // dev_dbg(&intf->dev, "%s: status %d cnt %d\n", // __FUNCTION__, status, intf->pm_usage_cnt); return status; } EXPORT_SYMBOL_GPL(usb_autopm_get_interface); #endif /* CONFIG_USB_SUSPEND */ static int usb_suspend(struct device *dev, pm_message_t message) { int status; if (is_usb_device(dev)) { struct usb_device *udev = to_usb_device(dev); usb_pm_lock(udev); udev->auto_pm = 0; status = usb_suspend_both(udev, message); usb_pm_unlock(udev); } else status = 0; return status; } static int usb_resume(struct device *dev) { int status; if (is_usb_device(dev)) { struct usb_device *udev = to_usb_device(dev); usb_pm_lock(udev); udev->auto_pm = 0; status = usb_resume_both(udev); usb_pm_unlock(udev); /* Rebind drivers that had no suspend method? */ } else status = 0; return status; } #endif /* CONFIG_PM */ struct bus_type usb_bus_type = { .name = "usb", .match = usb_device_match, .uevent = usb_uevent, #ifdef CONFIG_PM .suspend = usb_suspend, .resume = usb_resume, #endif };