From stern@rowland.harvard.edu Sat Jul 1 19:08:54 2006 Date: Sat, 1 Jul 2006 22:08:49 -0400 (EDT) From: Alan Stern To: Greg KH Subject: [PATCH 06/15] usbcore: add usb_device_driver definition Message-ID: 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/driver.c | 219 +++++++++++++++++++++++++++++++++------------ drivers/usb/core/generic.c | 17 --- drivers/usb/core/usb.c | 15 +-- drivers/usb/core/usb.h | 20 +++- include/linux/usb.h | 58 ++++++++++- 5 files changed, 245 insertions(+), 84 deletions(-) --- gregkh-2.6.orig/drivers/usb/core/driver.c +++ gregkh-2.6/drivers/usb/core/driver.c @@ -84,7 +84,7 @@ static int usb_create_newid_file(struct 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 @@ static void usb_remove_newid_file(struct 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 @@ static const struct usb_device_id *usb_m } -/* 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 @@ static int usb_probe_interface(struct de 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 @@ int usb_driver_claim_interface(struct us 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 @@ void usb_driver_release_interface(struct 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 @@ EXPORT_SYMBOL_GPL_FUTURE(usb_match_id); 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; - - /* check for generic driver, which we don't match any device with */ - if (drv == &usb_generic_driver) - return 0; + /* devices and interfaces are handled separately */ + if (is_usb_device(dev)) { - intf = to_usb_interface(dev); - usb_drv = to_usb_driver(drv); + /* interface drivers never match devices */ + if (!is_usb_device_driver(drv)) + return 0; - 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 @@ static int usb_uevent(struct device *dev /* 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 @@ static int usb_uevent(struct device *dev #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 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 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 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 @@ int usb_register_driver(struct usb_drive 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 @@ int usb_register_driver(struct usb_drive 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 @@ EXPORT_SYMBOL_GPL_FUTURE(usb_register_dr */ 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 @@ static int usb_generic_suspend(struct de * 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 @@ static int usb_generic_suspend(struct de 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 @@ static int usb_generic_resume(struct dev 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; } --- gregkh-2.6.orig/drivers/usb/core/generic.c +++ gregkh-2.6/drivers/usb/core/generic.c @@ -21,14 +21,12 @@ #include #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 @@ static int generic_remove(struct device /* 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; --- gregkh-2.6.orig/drivers/usb/core/usb.c +++ gregkh-2.6/drivers/usb/core/usb.c @@ -123,7 +123,7 @@ static int __find_interface(struct devic 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 @@ struct usb_interface *usb_find_interface 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 @@ usb_alloc_dev(struct usb_device *parent, 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; @@ -836,7 +839,7 @@ static int __init usb_init(void) 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; @@ -866,7 +869,7 @@ static void __exit usb_exit(void) if (nousb) return; - driver_unregister(&usb_generic_driver); + usb_deregister_device_driver(&usb_generic_driver); usb_major_cleanup(); usbfs_cleanup(); usb_deregister(&usbfs_driver); --- gregkh-2.6.orig/drivers/usb/core/usb.h +++ gregkh-2.6/drivers/usb/core/usb.h @@ -34,8 +34,24 @@ extern int usb_port_suspend(struct usb_d 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 */ --- gregkh-2.6.orig/include/linux/usb.h +++ gregkh-2.6/include/linux/usb.h @@ -541,7 +541,17 @@ struct usb_dynids { }; /** - * struct usb_driver - identifies USB driver to usbcore + * struct usbdrv_wrap - wrapper for driver-model structure + * @driver: The driver-model core driver structure. + * @for_devices: Non-zero for device drivers, 0 for interface drivers. + */ +struct usbdrv_wrap { + struct device_driver driver; + int for_devices; +}; + +/** + * struct usb_driver - identifies USB interface driver to usbcore * @name: The driver name should be unique among USB drivers, * and should normally be the same as the module name. * @probe: Called to see if the driver is willing to manage a particular @@ -568,12 +578,12 @@ struct usb_dynids { * or your driver's probe function will never get called. * @dynids: used internally to hold the list of dynamically added device * ids for this driver. - * @driver: the driver model core driver structure. + * @drvwrap: Driver-model core structure wrapper. * @no_dynamic_id: if set to 1, the USB core will not allow dynamic ids to be * added to this driver by preventing the sysfs file from being created. * - * USB drivers must provide a name, probe() and disconnect() methods, - * and an id_table. Other driver fields are optional. + * USB interface drivers must provide a name, probe() and disconnect() + * methods, and an id_table. Other driver fields are optional. * * The id_table is used in hotplugging. It holds a set of descriptors, * and specialized data may be associated with each entry. That table @@ -607,10 +617,40 @@ struct usb_driver { const struct usb_device_id *id_table; struct usb_dynids dynids; - struct device_driver driver; + struct usbdrv_wrap drvwrap; unsigned int no_dynamic_id:1; }; -#define to_usb_driver(d) container_of(d, struct usb_driver, driver) +#define to_usb_driver(d) container_of(d, struct usb_driver, drvwrap.driver) + +/** + * struct usb_device_driver - identifies USB device driver to usbcore + * @name: The driver name should be unique among USB drivers, + * and should normally be the same as the module name. + * @probe: Called to see if the driver is willing to manage a particular + * device. If it is, probe returns zero and uses dev_set_drvdata() + * to associate driver-specific data with the device. If unwilling + * to manage the device, return a negative errno value. + * @disconnect: Called when the device is no longer accessible, usually + * because it has been (or is being) disconnected or the driver's + * module is being unloaded. + * @suspend: Called when the device is going to be suspended by the system. + * @resume: Called when the device is being resumed by the system. + * @drvwrap: Driver-model core structure wrapper. + * + * USB drivers must provide all the fields listed above except drvwrap. + */ +struct usb_device_driver { + const char *name; + + int (*probe) (struct usb_device *udev); + void (*disconnect) (struct usb_device *udev); + + int (*suspend) (struct usb_device *udev, pm_message_t message); + int (*resume) (struct usb_device *udev); + struct usbdrv_wrap drvwrap; +}; +#define to_usb_device_driver(d) container_of(d, struct usb_device_driver, \ + drvwrap.driver) extern struct bus_type usb_bus_type; @@ -634,13 +674,17 @@ struct usb_class_driver { * use these in module_init()/module_exit() * and don't forget MODULE_DEVICE_TABLE(usb, ...) */ -int usb_register_driver(struct usb_driver *, struct module *); +extern int usb_register_driver(struct usb_driver *, struct module *); static inline int usb_register(struct usb_driver *driver) { return usb_register_driver(driver, THIS_MODULE); } extern void usb_deregister(struct usb_driver *); +extern int usb_register_device_driver(struct usb_device_driver *, + struct module *); +extern void usb_deregister_device_driver(struct usb_device_driver *); + extern int usb_register_dev(struct usb_interface *intf, struct usb_class_driver *class_driver); extern void usb_deregister_dev(struct usb_interface *intf,