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path: root/drivers/usb/core/driver.c
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Diffstat (limited to 'drivers/usb/core/driver.c')
-rw-r--r--drivers/usb/core/driver.c348
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
+};