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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337// SPDX-License-Identifier: GPL-2.0/* * drivers/usb/core/generic.c - generic driver for USB devices (not interfaces) * * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de> * * 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 * * Released under the GPLv2 only. */
#include <linux/usb.h>#include <linux/usb/hcd.h>#include <linux/string_choices.h>#include <uapi/linux/usb/audio.h>#include "usb.h"
static int is_rndis(struct usb_interface_descriptor *desc){ return desc->bInterfaceClass == USB_CLASS_COMM && desc->bInterfaceSubClass == 2 && desc->bInterfaceProtocol == 0xff;}
static int is_activesync(struct usb_interface_descriptor *desc){ return desc->bInterfaceClass == USB_CLASS_MISC && desc->bInterfaceSubClass == 1 && desc->bInterfaceProtocol == 1;}
static bool is_audio(struct usb_interface_descriptor *desc){ return desc->bInterfaceClass == USB_CLASS_AUDIO;}
static bool is_uac3_config(struct usb_interface_descriptor *desc){ return desc->bInterfaceProtocol == UAC_VERSION_3;}
int usb_choose_configuration(struct usb_device *udev){ int i; int num_configs; int insufficient_power = 0; struct usb_host_config *c, *best; struct usb_device_driver *udriver;
/* * If a USB device (not an interface) doesn't have a driver then the * kernel has no business trying to select or install a configuration * for it. */ if (!udev->dev.driver) return -1; udriver = to_usb_device_driver(udev->dev.driver);
if (usb_device_is_owned(udev)) return 0;
if (udriver->choose_configuration) { i = udriver->choose_configuration(udev); if (i >= 0) return i; }
best = NULL; c = udev->config; num_configs = udev->descriptor.bNumConfigurations; for (i = 0; i < num_configs; (i++, c++)) { struct usb_interface_descriptor *desc = NULL;
/* It's possible that a config has no interfaces! */ if (c->desc.bNumInterfaces > 0) desc = &c->intf_cache[0]->altsetting->desc;
/* * HP's USB bus-powered keyboard has only one configuration * and it claims to be self-powered; other devices may have * similar errors in their descriptors. If the next test * were allowed to execute, such configurations would always * be rejected and the devices would not work as expected. * In the meantime, we run the risk of selecting a config * that requires external power at a time when that power * isn't available. It seems to be the lesser of two evils. * * Bugzilla #6448 reports a device that appears to crash * when it receives a GET_DEVICE_STATUS request! We don't * have any other way to tell whether a device is self-powered, * but since we don't use that information anywhere but here, * the call has been removed. * * Maybe the GET_DEVICE_STATUS call and the test below can * be reinstated when device firmwares become more reliable. * Don't hold your breath. */#if 0 /* Rule out self-powered configs for a bus-powered device */ if (bus_powered && (c->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)) continue;#endif
/* * The next test may not be as effective as it should be. * Some hubs have errors in their descriptor, claiming * to be self-powered when they are really bus-powered. * We will overestimate the amount of current such hubs * make available for each port. * * This is a fairly benign sort of failure. It won't * cause us to reject configurations that we should have * accepted. */
/* Rule out configs that draw too much bus current */ if (usb_get_max_power(udev, c) > udev->bus_mA) { insufficient_power++; continue; }
/* * Select first configuration as default for audio so that * devices that don't comply with UAC3 protocol are supported. * But, still iterate through other configurations and * select UAC3 compliant config if present. */ if (desc && is_audio(desc)) { /* Always prefer the first found UAC3 config */ if (is_uac3_config(desc)) { best = c; break; }
/* If there is no UAC3 config, prefer the first config */ else if (i == 0) best = c;
/* Unconditional continue, because the rest of the code * in the loop is irrelevant for audio devices, and * because it can reassign best, which for audio devices * we don't want. */ continue; }
/* When the first config's first interface is one of Microsoft's * pet nonstandard Ethernet-over-USB protocols, ignore it unless * this kernel has enabled the necessary host side driver. * But: Don't ignore it if it's the only config. */ if (i == 0 && num_configs > 1 && desc && (is_rndis(desc) || is_activesync(desc))) {#if !defined(CONFIG_USB_NET_RNDIS_HOST) && !defined(CONFIG_USB_NET_RNDIS_HOST_MODULE) continue;#else best = c;#endif }
/* From the remaining configs, choose the first one whose * first interface is for a non-vendor-specific class. * Reason: Linux is more likely to have a class driver * than a vendor-specific driver. */ else if (udev->descriptor.bDeviceClass != USB_CLASS_VENDOR_SPEC && (desc && desc->bInterfaceClass != USB_CLASS_VENDOR_SPEC)) { best = c; break; }
/* If all the remaining configs are vendor-specific, * choose the first one. */ else if (!best) best = c; }
if (insufficient_power > 0) dev_info(&udev->dev, "rejected %d configuration%s " "due to insufficient available bus power\n", insufficient_power, str_plural(insufficient_power));
if (best) { i = best->desc.bConfigurationValue; dev_dbg(&udev->dev, "configuration #%d chosen from %d choice%s\n", i, num_configs, str_plural(num_configs)); } else { i = -1; dev_warn(&udev->dev, "no configuration chosen from %d choice%s\n", num_configs, str_plural(num_configs)); } return i;}EXPORT_SYMBOL_GPL(usb_choose_configuration);
static int __check_for_non_generic_match(struct device_driver *drv, void *data){ struct usb_device *udev = data; struct usb_device_driver *udrv;
if (!is_usb_device_driver(drv)) return 0; udrv = to_usb_device_driver(drv); if (udrv == &usb_generic_driver) return 0; return usb_driver_applicable(udev, udrv);}
static bool usb_generic_driver_match(struct usb_device *udev){ if (udev->use_generic_driver) return true;
/* * If any other driver wants the device, leave the device to this other * driver. */ if (bus_for_each_drv(&usb_bus_type, NULL, udev, __check_for_non_generic_match)) return false;
return true;}
int usb_generic_driver_probe(struct usb_device *udev){ int err, c;
/* Choose and set the configuration. This registers the interfaces * with the driver core and lets interface drivers bind to them. */ if (udev->authorized == 0) dev_info(&udev->dev, "Device is not authorized for usage\n"); else { c = usb_choose_configuration(udev); if (c >= 0) { err = usb_set_configuration(udev, c); if (err && err != -ENODEV) { dev_err(&udev->dev, "can't set config #%d, error %d\n", c, err); /* This need not be fatal. The user can try to * set other configurations. */ } } } /* USB device state == configured ... usable */ usb_notify_add_device(udev);
return 0;}
void usb_generic_driver_disconnect(struct usb_device *udev){ usb_notify_remove_device(udev);
/* if this is only an unbind, not a physical disconnect, then * unconfigure the device */ if (udev->actconfig) usb_set_configuration(udev, -1);}
#ifdef CONFIG_PM
int usb_generic_driver_suspend(struct usb_device *udev, pm_message_t msg){ int rc;
/* Normal USB devices suspend through their upstream port. * Root hubs don't have upstream ports to suspend, * so we have to shut down their downstream HC-to-USB * interfaces manually by doing a bus (or "global") suspend. */ if (!udev->parent) rc = hcd_bus_suspend(udev, msg);
/* * Non-root USB2 devices don't need to do anything for FREEZE * or PRETHAW. USB3 devices don't support global suspend and * needs to be selectively suspended. */ else if ((msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_PRETHAW) && (udev->speed < USB_SPEED_SUPER)) rc = 0; else rc = usb_port_suspend(udev, msg);
if (rc == 0) usbfs_notify_suspend(udev); return rc;}
int usb_generic_driver_resume(struct usb_device *udev, pm_message_t msg){ int rc;
/* Normal USB devices resume/reset through their upstream port. * Root hubs don't have upstream ports to resume or reset, * so we have to start up their downstream HC-to-USB * interfaces manually by doing a bus (or "global") resume. */ if (!udev->parent) rc = hcd_bus_resume(udev, msg); else rc = usb_port_resume(udev, msg);
if (rc == 0) usbfs_notify_resume(udev); return rc;}
#endif /* CONFIG_PM */
struct usb_device_driver usb_generic_driver = { .name = "usb", .match = usb_generic_driver_match, .probe = usb_generic_driver_probe, .disconnect = usb_generic_driver_disconnect,#ifdef CONFIG_PM .suspend = usb_generic_driver_suspend, .resume = usb_generic_driver_resume,#endif .supports_autosuspend = 1,};