diff options
Diffstat (limited to 'drivers/usb/core/driver.c')
-rw-r--r-- | drivers/usb/core/driver.c | 348 |
1 files changed, 315 insertions, 33 deletions
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index ec890650141..8dcf2cd0c56 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -17,7 +17,8 @@ * * NOTE! This is not actually a driver at all, rather this is * just a collection of helper routines that implement the - * generic USB things that the real drivers can use.. + * matching, probing, releasing, suspending and resuming for + * real drivers. * */ @@ -34,38 +35,6 @@ struct usb_dynid { struct usb_device_id id; }; - -static int generic_probe(struct device *dev) -{ - return 0; -} -static int generic_remove(struct device *dev) -{ - struct usb_device *udev = to_usb_device(dev); - - /* if this is only an unbind, not a physical disconnect, then - * unconfigure the device */ - if (udev->state == USB_STATE_CONFIGURED) - usb_set_configuration(udev, 0); - - /* in case the call failed or the device was suspended */ - if (udev->state >= USB_STATE_CONFIGURED) - usb_disable_device(udev, 0); - return 0; -} - -struct device_driver usb_generic_driver = { - .owner = THIS_MODULE, - .name = "usb", - .bus = &usb_bus_type, - .probe = generic_probe, - .remove = generic_remove, -}; - -/* Fun hack to determine if the struct device is a - * usb device or a usb interface. */ -int usb_generic_driver_data; - #ifdef CONFIG_HOTPLUG /* @@ -238,6 +207,89 @@ static int usb_unbind_interface(struct device *dev) 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; + + if (dev->driver) + return -EBUSY; + + dev->driver = &driver->driver; + usb_set_intfdata(iface, priv); + iface->condition = USB_INTERFACE_BOUND; + mark_active(iface); + + /* if interface was already added, bind now; else let + * the future device_add() bind it, bypassing probe() + */ + if (device_is_registered(dev)) + device_bind_driver(dev); + + return 0; +} +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; + + /* this should never happen, don't release something that's not ours */ + if (!dev->driver || dev->driver != &driver->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); + iface->condition = USB_INTERFACE_UNBOUND; + mark_quiesced(iface); +} +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) @@ -402,6 +454,120 @@ int usb_device_match(struct device *dev, struct device_driver *drv) 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); + + /* Must check driver_data here, as on remove driver is always NULL */ + if ((dev->driver == &usb_generic_driver) || + (dev->driver_data == &usb_generic_driver_data)) + return 0; + + 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 (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_driver - register a USB driver * @new_driver: USB operations for the driver @@ -469,3 +635,119 @@ void usb_deregister(struct usb_driver *driver) usbfs_update_special(); } EXPORT_SYMBOL_GPL_FUTURE(usb_deregister); + +#ifdef CONFIG_PM + +static int verify_suspended(struct device *dev, void *unused) +{ + if (dev->driver == NULL) + return 0; + return (dev->power.power_state.event == PM_EVENT_ON) ? -EBUSY : 0; +} + +static int usb_generic_suspend(struct device *dev, pm_message_t message) +{ + struct usb_interface *intf; + struct usb_driver *driver; + int status; + + /* USB devices enter SUSPEND state through their hubs, but can be + * marked for FREEZE as soon as their children are already idled. + * But those semantics are useless, so we equate the two (sigh). + */ + if (dev->driver == &usb_generic_driver) { + if (dev->power.power_state.event == message.event) + return 0; + /* we need to rule out bogus requests through sysfs */ + status = device_for_each_child(dev, NULL, verify_suspended); + if (status) + return status; + return usb_port_suspend(to_usb_device(dev)); + } + + if ((dev->driver == NULL) || + (dev->driver_data == &usb_generic_driver_data)) + return 0; + + intf = to_usb_interface(dev); + driver = to_usb_driver(dev->driver); + + /* with no hardware, USB interfaces only use FREEZE and ON states */ + if (!is_active(intf)) + return 0; + + if (driver->suspend && driver->resume) { + status = driver->suspend(intf, message); + if (status) + dev_err(dev, "%s error %d\n", "suspend", status); + else + mark_quiesced(intf); + } else { + // FIXME else if there's no suspend method, disconnect... + dev_warn(dev, "no suspend for driver %s?\n", driver->name); + mark_quiesced(intf); + status = 0; + } + return status; +} + +static int usb_generic_resume(struct device *dev) +{ + struct usb_interface *intf; + struct usb_driver *driver; + struct usb_device *udev; + int status; + + if (dev->power.power_state.event == PM_EVENT_ON) + return 0; + + /* mark things as "on" immediately, no matter what errors crop up */ + dev->power.power_state.event = PM_EVENT_ON; + + /* devices resume through their hubs */ + if (dev->driver == &usb_generic_driver) { + udev = to_usb_device(dev); + if (udev->state == USB_STATE_NOTATTACHED) + return 0; + return usb_port_resume(udev); + } + + if ((dev->driver == NULL) || + (dev->driver_data == &usb_generic_driver_data)) { + dev->power.power_state.event = PM_EVENT_FREEZE; + return 0; + } + + intf = to_usb_interface(dev); + driver = to_usb_driver(dev->driver); + + udev = interface_to_usbdev(intf); + if (udev->state == USB_STATE_NOTATTACHED) + return 0; + + /* if driver was suspended, it has a resume method; + * however, sysfs can wrongly mark things as suspended + * (on the "no suspend method" FIXME path above) + */ + if (driver->resume) { + status = driver->resume(intf); + if (status) { + dev_err(dev, "%s error %d\n", "resume", status); + mark_quiesced(intf); + } + } else + dev_warn(dev, "no resume for driver %s?\n", driver->name); + return 0; +} + +#endif /* CONFIG_PM */ + +struct bus_type usb_bus_type = { + .name = "usb", + .match = usb_device_match, + .uevent = usb_uevent, +#ifdef CONFIG_PM + .suspend = usb_generic_suspend, + .resume = usb_generic_resume, +#endif +}; |