usbcore: add usb_device_driver definition
This patch (as732) adds a usb_device_driver structure, for representing
drivers that manage an entire USB device as opposed to just an
interface. Support routines like usb_register_device_driver,
usb_deregister_device_driver, usb_probe_device, and usb_unbind_device
are also added.
Unlike an earlier version of this patch, the new code is type-safe. To
accomplish this, the existing struct driver embedded in struct
usb_driver had to be wrapped in an intermediate wrapper. This enables
the core to tell at runtime whether a particular struct driver belongs
to a device driver or to an interface driver.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 8dcf2cd..0d4b5dc 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -84,7 +84,7 @@
goto exit;
if (usb_drv->probe != NULL)
- error = sysfs_create_file(&usb_drv->driver.kobj,
+ error = sysfs_create_file(&usb_drv->drvwrap.driver.kobj,
&driver_attr_new_id.attr);
exit:
return error;
@@ -96,7 +96,7 @@
return;
if (usb_drv->probe != NULL)
- sysfs_remove_file(&usb_drv->driver.kobj,
+ sysfs_remove_file(&usb_drv->drvwrap.driver.kobj,
&driver_attr_new_id.attr);
}
@@ -143,18 +143,55 @@
}
-/* called from driver core with usb_bus_type.subsys writelock */
+/* 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);
+
+ /* FIXME: resume a suspended device */
+ if (udev->state == USB_STATE_SUSPENDED)
+ return -EHOSTUNREACH;
+
+ /* TODO: Add real matching code */
+
+ 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_interface * intf = to_usb_interface(dev);
- struct usb_driver * driver = to_usb_driver(dev->driver);
+ struct usb_driver *driver = to_usb_driver(dev->driver);
+ struct usb_interface *intf;
const struct usb_device_id *id;
int error = -ENODEV;
dev_dbg(dev, "%s\n", __FUNCTION__);
- if (!driver->probe)
+ if (is_usb_device(dev)) /* Sanity check */
return error;
+
+ intf = to_usb_interface(dev);
+
/* FIXME we'd much prefer to just resume it ... */
if (interface_to_usbdev(intf)->state == USB_STATE_SUSPENDED)
return -EHOSTUNREACH;
@@ -182,19 +219,18 @@
return error;
}
-/* called from driver core with usb_bus_type.subsys writelock */
+/* 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_driver *driver = to_usb_driver(intf->dev.driver);
intf->condition = USB_INTERFACE_UNBINDING;
/* release all urbs for this interface */
usb_disable_interface(interface_to_usbdev(intf), intf);
- if (driver && driver->disconnect)
- driver->disconnect(intf);
+ driver->disconnect(intf);
/* reset other interface state */
usb_set_interface(interface_to_usbdev(intf),
@@ -235,7 +271,7 @@
if (dev->driver)
return -EBUSY;
- dev->driver = &driver->driver;
+ dev->driver = &driver->drvwrap.driver;
usb_set_intfdata(iface, priv);
iface->condition = USB_INTERFACE_BOUND;
mark_active(iface);
@@ -270,7 +306,7 @@
struct device *dev = &iface->dev;
/* this should never happen, don't release something that's not ours */
- if (!dev->driver || dev->driver != &driver->driver)
+ if (!dev->driver || dev->driver != &driver->drvwrap.driver)
return;
/* don't release from within disconnect() */
@@ -433,24 +469,37 @@
int usb_device_match(struct device *dev, struct device_driver *drv)
{
- struct usb_interface *intf;
- struct usb_driver *usb_drv;
- const struct usb_device_id *id;
+ /* devices and interfaces are handled separately */
+ if (is_usb_device(dev)) {
- /* check for generic driver, which we don't match any device with */
- if (drv == &usb_generic_driver)
- return 0;
+ /* interface drivers never match devices */
+ 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)
+ /* TODO: Add real matching code */
return 1;
- id = usb_match_dynamic_id(intf, usb_drv);
- if (id)
- 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;
}
@@ -481,14 +530,13 @@
/* 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))
+ if (is_usb_device(dev))
return 0;
-
- intf = to_usb_interface(dev);
- usb_dev = interface_to_usbdev (intf);
- alt = intf->cur_altsetting;
+ 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);
@@ -569,13 +617,71 @@
#endif /* CONFIG_HOTPLUG */
/**
- * usb_register_driver - register a USB driver
- * @new_driver: USB operations for the driver
+ * 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 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 devices.
+ * 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
@@ -589,23 +695,25 @@
if (usb_disabled())
return -ENODEV;
- new_driver->driver.name = (char *)new_driver->name;
- new_driver->driver.bus = &usb_bus_type;
- new_driver->driver.probe = usb_probe_interface;
- new_driver->driver.remove = usb_unbind_interface;
- new_driver->driver.owner = owner;
+ 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->driver);
+ retval = driver_register(&new_driver->drvwrap.driver);
if (!retval) {
- pr_info("%s: registered new driver %s\n",
+ 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 driver %s\n",
+ printk(KERN_ERR "%s: error %d registering interface "
+ " driver %s\n",
usbcore_name, retval, new_driver->name);
}
@@ -614,8 +722,8 @@
EXPORT_SYMBOL_GPL_FUTURE(usb_register_driver);
/**
- * usb_deregister - unregister a USB driver
- * @driver: USB operations of the driver to unregister
+ * 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.
@@ -626,11 +734,12 @@
*/
void usb_deregister(struct usb_driver *driver)
{
- pr_info("%s: deregistering driver %s\n", usbcore_name, driver->name);
+ pr_info("%s: deregistering interface driver %s\n",
+ usbcore_name, driver->name);
usb_remove_newid_file(driver);
usb_free_dynids(driver);
- driver_unregister(&driver->driver);
+ driver_unregister(&driver->drvwrap.driver);
usbfs_update_special();
}
@@ -655,7 +764,7 @@
* 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 (is_usb_device(dev)) {
if (dev->power.power_state.event == message.event)
return 0;
/* we need to rule out bogus requests through sysfs */
@@ -665,8 +774,7 @@
return usb_port_suspend(to_usb_device(dev));
}
- if ((dev->driver == NULL) ||
- (dev->driver_data == &usb_generic_driver_data))
+ if (dev->driver == NULL)
return 0;
intf = to_usb_interface(dev);
@@ -705,15 +813,14 @@
dev->power.power_state.event = PM_EVENT_ON;
/* devices resume through their hubs */
- if (dev->driver == &usb_generic_driver) {
+ if (is_usb_device(dev)) {
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)) {
+ if (dev->driver == NULL) {
dev->power.power_state.event = PM_EVENT_FREEZE;
return 0;
}
diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c
index 7bab976..fa6f34a 100644
--- a/drivers/usb/core/generic.c
+++ b/drivers/usb/core/generic.c
@@ -21,14 +21,12 @@
#include <linux/usb.h>
#include "usb.h"
-static int generic_probe(struct device *dev)
+static int generic_probe(struct usb_device *udev)
{
return 0;
}
-static int generic_remove(struct device *dev)
+static void generic_disconnect(struct usb_device *udev)
{
- 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)
@@ -37,17 +35,10 @@
/* 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,
+struct usb_device_driver usb_generic_driver = {
.name = "usb",
- .bus = &usb_bus_type,
.probe = generic_probe,
- .remove = generic_remove,
+ .disconnect = generic_disconnect,
};
-
-/* Fun hack to determine if the struct device is a
- * usb device or a usb interface. */
-int usb_generic_driver_data;
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 0b8c67b..6dfbc28 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -123,7 +123,7 @@
struct usb_interface *intf;
/* can't look at usb devices, only interfaces */
- if (dev->driver == &usb_generic_driver)
+ if (is_usb_device(dev))
return 0;
intf = to_usb_interface(dev);
@@ -149,7 +149,8 @@
argb.minor = minor;
argb.interface = NULL;
- driver_for_each_device(&drv->driver, NULL, &argb, __find_interface);
+ driver_for_each_device(&drv->drvwrap.driver, NULL, &argb,
+ __find_interface);
return argb.interface;
}
@@ -204,11 +205,13 @@
device_initialize(&dev->dev);
dev->dev.bus = &usb_bus_type;
dev->dev.dma_mask = bus->controller->dma_mask;
- dev->dev.driver_data = &usb_generic_driver_data;
- dev->dev.driver = &usb_generic_driver;
+ dev->dev.driver = &usb_generic_driver.drvwrap.driver;
dev->dev.release = usb_release_dev;
dev->state = USB_STATE_ATTACHED;
+ /* This magic assignment distinguishes devices from interfaces */
+ dev->dev.platform_data = &usb_generic_driver;
+
INIT_LIST_HEAD(&dev->ep0.urb_list);
dev->ep0.desc.bLength = USB_DT_ENDPOINT_SIZE;
dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
@@ -838,7 +841,7 @@
retval = usb_hub_init();
if (retval)
goto hub_init_failed;
- retval = driver_register(&usb_generic_driver);
+ retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
if (!retval)
goto out;
@@ -868,7 +871,7 @@
if (nousb)
return;
- driver_unregister(&usb_generic_driver);
+ usb_deregister_device_driver(&usb_generic_driver);
usb_major_cleanup();
usbfs_cleanup();
usb_deregister(&usbfs_driver);
diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index 82d397a..1d25cca 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -34,8 +34,24 @@
extern int usb_port_resume(struct usb_device *dev);
extern struct bus_type usb_bus_type;
-extern struct device_driver usb_generic_driver;
-extern int usb_generic_driver_data;
+extern struct usb_device_driver usb_generic_driver;
+
+/* Here's how we tell apart devices and interfaces. Luckily there's
+ * no such thing as a platform USB device, so we can steal the use
+ * of the platform_data field. */
+
+static inline int is_usb_device(struct device *dev)
+{
+ return dev->platform_data == &usb_generic_driver;
+}
+
+/* Do the same for device drivers and interface drivers. */
+
+static inline int is_usb_device_driver(struct device_driver *drv)
+{
+ return container_of(drv, struct usbdrv_wrap, driver)->
+ for_devices;
+}
/* Interfaces and their "power state" are owned by usbcore */