1aa1f3bb5SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0 236e56a34SAlan Stern /* 336e56a34SAlan Stern * drivers/usb/generic.c - generic driver for USB devices (not interfaces) 436e56a34SAlan Stern * 536e56a34SAlan Stern * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de> 636e56a34SAlan Stern * 736e56a34SAlan Stern * based on drivers/usb/usb.c which had the following copyrights: 836e56a34SAlan Stern * (C) Copyright Linus Torvalds 1999 936e56a34SAlan Stern * (C) Copyright Johannes Erdfelt 1999-2001 1036e56a34SAlan Stern * (C) Copyright Andreas Gal 1999 1136e56a34SAlan Stern * (C) Copyright Gregory P. Smith 1999 1236e56a34SAlan Stern * (C) Copyright Deti Fliegl 1999 (new USB architecture) 1336e56a34SAlan Stern * (C) Copyright Randy Dunlap 2000 1436e56a34SAlan Stern * (C) Copyright David Brownell 2000-2004 1536e56a34SAlan Stern * (C) Copyright Yggdrasil Computing, Inc. 2000 1636e56a34SAlan Stern * (usb_device_id matching changes by Adam J. Richter) 1736e56a34SAlan Stern * (C) Copyright Greg Kroah-Hartman 2002-2003 1836e56a34SAlan Stern * 19b65fba3dSGreg Kroah-Hartman * Released under the GPLv2 only. 2036e56a34SAlan Stern */ 2136e56a34SAlan Stern 2236e56a34SAlan Stern #include <linux/usb.h> 2327729aadSEric Lescouet #include <linux/usb/hcd.h> 24f13912d3SSaranya Gopal #include <uapi/linux/usb/audio.h> 2536e56a34SAlan Stern #include "usb.h" 2636e56a34SAlan Stern 27782da727SAlan Stern static inline const char *plural(int n) 28782da727SAlan Stern { 29782da727SAlan Stern return (n == 1 ? "" : "s"); 30782da727SAlan Stern } 31782da727SAlan Stern 32ad55d71aSOle Andre Vadla Ravnas static int is_rndis(struct usb_interface_descriptor *desc) 33ad55d71aSOle Andre Vadla Ravnas { 34ad55d71aSOle Andre Vadla Ravnas return desc->bInterfaceClass == USB_CLASS_COMM 35ad55d71aSOle Andre Vadla Ravnas && desc->bInterfaceSubClass == 2 36ad55d71aSOle Andre Vadla Ravnas && desc->bInterfaceProtocol == 0xff; 37ad55d71aSOle Andre Vadla Ravnas } 38ad55d71aSOle Andre Vadla Ravnas 39ad55d71aSOle Andre Vadla Ravnas static int is_activesync(struct usb_interface_descriptor *desc) 40ad55d71aSOle Andre Vadla Ravnas { 41ad55d71aSOle Andre Vadla Ravnas return desc->bInterfaceClass == USB_CLASS_MISC 42ad55d71aSOle Andre Vadla Ravnas && desc->bInterfaceSubClass == 1 43ad55d71aSOle Andre Vadla Ravnas && desc->bInterfaceProtocol == 1; 44ad55d71aSOle Andre Vadla Ravnas } 45ad55d71aSOle Andre Vadla Ravnas 46f13912d3SSaranya Gopal static bool is_audio(struct usb_interface_descriptor *desc) 47f13912d3SSaranya Gopal { 48f13912d3SSaranya Gopal return desc->bInterfaceClass == USB_CLASS_AUDIO; 49f13912d3SSaranya Gopal } 50f13912d3SSaranya Gopal 51f13912d3SSaranya Gopal static bool is_uac3_config(struct usb_interface_descriptor *desc) 52f13912d3SSaranya Gopal { 53f13912d3SSaranya Gopal return desc->bInterfaceProtocol == UAC_VERSION_3; 54f13912d3SSaranya Gopal } 55f13912d3SSaranya Gopal 56b5ea060fSGreg Kroah-Hartman int usb_choose_configuration(struct usb_device *udev) 57782da727SAlan Stern { 58782da727SAlan Stern int i; 59782da727SAlan Stern int num_configs; 60782da727SAlan Stern int insufficient_power = 0; 61782da727SAlan Stern struct usb_host_config *c, *best; 62782da727SAlan Stern 63c13b86a3SHindin Joseph if (usb_device_is_owned(udev)) 64c13b86a3SHindin Joseph return 0; 65c13b86a3SHindin Joseph 66782da727SAlan Stern best = NULL; 67782da727SAlan Stern c = udev->config; 68782da727SAlan Stern num_configs = udev->descriptor.bNumConfigurations; 69782da727SAlan Stern for (i = 0; i < num_configs; (i++, c++)) { 70782da727SAlan Stern struct usb_interface_descriptor *desc = NULL; 71782da727SAlan Stern 72782da727SAlan Stern /* It's possible that a config has no interfaces! */ 73782da727SAlan Stern if (c->desc.bNumInterfaces > 0) 74782da727SAlan Stern desc = &c->intf_cache[0]->altsetting->desc; 75782da727SAlan Stern 76782da727SAlan Stern /* 77782da727SAlan Stern * HP's USB bus-powered keyboard has only one configuration 78782da727SAlan Stern * and it claims to be self-powered; other devices may have 79782da727SAlan Stern * similar errors in their descriptors. If the next test 80782da727SAlan Stern * were allowed to execute, such configurations would always 81782da727SAlan Stern * be rejected and the devices would not work as expected. 82782da727SAlan Stern * In the meantime, we run the risk of selecting a config 83782da727SAlan Stern * that requires external power at a time when that power 84782da727SAlan Stern * isn't available. It seems to be the lesser of two evils. 85782da727SAlan Stern * 86782da727SAlan Stern * Bugzilla #6448 reports a device that appears to crash 87782da727SAlan Stern * when it receives a GET_DEVICE_STATUS request! We don't 88782da727SAlan Stern * have any other way to tell whether a device is self-powered, 89782da727SAlan Stern * but since we don't use that information anywhere but here, 90782da727SAlan Stern * the call has been removed. 91782da727SAlan Stern * 92782da727SAlan Stern * Maybe the GET_DEVICE_STATUS call and the test below can 93782da727SAlan Stern * be reinstated when device firmwares become more reliable. 94782da727SAlan Stern * Don't hold your breath. 95782da727SAlan Stern */ 96782da727SAlan Stern #if 0 97782da727SAlan Stern /* Rule out self-powered configs for a bus-powered device */ 98782da727SAlan Stern if (bus_powered && (c->desc.bmAttributes & 99782da727SAlan Stern USB_CONFIG_ATT_SELFPOWER)) 100782da727SAlan Stern continue; 101782da727SAlan Stern #endif 102782da727SAlan Stern 103782da727SAlan Stern /* 104782da727SAlan Stern * The next test may not be as effective as it should be. 105782da727SAlan Stern * Some hubs have errors in their descriptor, claiming 106782da727SAlan Stern * to be self-powered when they are really bus-powered. 107782da727SAlan Stern * We will overestimate the amount of current such hubs 108782da727SAlan Stern * make available for each port. 109782da727SAlan Stern * 110782da727SAlan Stern * This is a fairly benign sort of failure. It won't 111782da727SAlan Stern * cause us to reject configurations that we should have 112782da727SAlan Stern * accepted. 113782da727SAlan Stern */ 114782da727SAlan Stern 115782da727SAlan Stern /* Rule out configs that draw too much bus current */ 1168d8479dbSSebastian Andrzej Siewior if (usb_get_max_power(udev, c) > udev->bus_mA) { 117782da727SAlan Stern insufficient_power++; 118782da727SAlan Stern continue; 119782da727SAlan Stern } 120782da727SAlan Stern 12125b01614SNikolay Yakimov /* 12225b01614SNikolay Yakimov * Select first configuration as default for audio so that 12325b01614SNikolay Yakimov * devices that don't comply with UAC3 protocol are supported. 12425b01614SNikolay Yakimov * But, still iterate through other configurations and 12525b01614SNikolay Yakimov * select UAC3 compliant config if present. 12625b01614SNikolay Yakimov */ 12725b01614SNikolay Yakimov if (desc && is_audio(desc)) { 12825b01614SNikolay Yakimov /* Always prefer the first found UAC3 config */ 12925b01614SNikolay Yakimov if (is_uac3_config(desc)) { 13025b01614SNikolay Yakimov best = c; 13125b01614SNikolay Yakimov break; 13225b01614SNikolay Yakimov } 13325b01614SNikolay Yakimov 13425b01614SNikolay Yakimov /* If there is no UAC3 config, prefer the first config */ 13525b01614SNikolay Yakimov else if (i == 0) 13625b01614SNikolay Yakimov best = c; 13725b01614SNikolay Yakimov 13825b01614SNikolay Yakimov /* Unconditional continue, because the rest of the code 13925b01614SNikolay Yakimov * in the loop is irrelevant for audio devices, and 14025b01614SNikolay Yakimov * because it can reassign best, which for audio devices 14125b01614SNikolay Yakimov * we don't want. 14225b01614SNikolay Yakimov */ 14325b01614SNikolay Yakimov continue; 14425b01614SNikolay Yakimov } 14525b01614SNikolay Yakimov 146ad55d71aSOle Andre Vadla Ravnas /* When the first config's first interface is one of Microsoft's 147ad55d71aSOle Andre Vadla Ravnas * pet nonstandard Ethernet-over-USB protocols, ignore it unless 148ad55d71aSOle Andre Vadla Ravnas * this kernel has enabled the necessary host side driver. 149c4e0b508SAlan Stern * But: Don't ignore it if it's the only config. 150ad55d71aSOle Andre Vadla Ravnas */ 151c4e0b508SAlan Stern if (i == 0 && num_configs > 1 && desc && 152c4e0b508SAlan Stern (is_rndis(desc) || is_activesync(desc))) { 153ad55d71aSOle Andre Vadla Ravnas #if !defined(CONFIG_USB_NET_RNDIS_HOST) && !defined(CONFIG_USB_NET_RNDIS_HOST_MODULE) 154782da727SAlan Stern continue; 155782da727SAlan Stern #else 156782da727SAlan Stern best = c; 157782da727SAlan Stern #endif 158782da727SAlan Stern } 159782da727SAlan Stern 160782da727SAlan Stern /* From the remaining configs, choose the first one whose 161782da727SAlan Stern * first interface is for a non-vendor-specific class. 162782da727SAlan Stern * Reason: Linux is more likely to have a class driver 163782da727SAlan Stern * than a vendor-specific driver. */ 164782da727SAlan Stern else if (udev->descriptor.bDeviceClass != 165782da727SAlan Stern USB_CLASS_VENDOR_SPEC && 16662f9cfa3SAlan Stern (desc && desc->bInterfaceClass != 167782da727SAlan Stern USB_CLASS_VENDOR_SPEC)) { 168782da727SAlan Stern best = c; 169782da727SAlan Stern break; 170782da727SAlan Stern } 171782da727SAlan Stern 172782da727SAlan Stern /* If all the remaining configs are vendor-specific, 173782da727SAlan Stern * choose the first one. */ 174782da727SAlan Stern else if (!best) 175782da727SAlan Stern best = c; 176782da727SAlan Stern } 177782da727SAlan Stern 178782da727SAlan Stern if (insufficient_power > 0) 179782da727SAlan Stern dev_info(&udev->dev, "rejected %d configuration%s " 180782da727SAlan Stern "due to insufficient available bus power\n", 181782da727SAlan Stern insufficient_power, plural(insufficient_power)); 182782da727SAlan Stern 183782da727SAlan Stern if (best) { 184782da727SAlan Stern i = best->desc.bConfigurationValue; 185b1f0a34cSMatthew Wilcox dev_dbg(&udev->dev, 186782da727SAlan Stern "configuration #%d chosen from %d choice%s\n", 187782da727SAlan Stern i, num_configs, plural(num_configs)); 188782da727SAlan Stern } else { 189782da727SAlan Stern i = -1; 190782da727SAlan Stern dev_warn(&udev->dev, 191782da727SAlan Stern "no configuration chosen from %d choice%s\n", 192782da727SAlan Stern num_configs, plural(num_configs)); 193782da727SAlan Stern } 194782da727SAlan Stern return i; 195782da727SAlan Stern } 196b7945b77SValentina Manea EXPORT_SYMBOL_GPL(usb_choose_configuration); 197782da727SAlan Stern 19888b7381aSBastien Nocera static int __check_usb_generic(struct device_driver *drv, void *data) 19988b7381aSBastien Nocera { 20088b7381aSBastien Nocera struct usb_device *udev = data; 20188b7381aSBastien Nocera struct usb_device_driver *udrv; 20288b7381aSBastien Nocera 20388b7381aSBastien Nocera if (!is_usb_device_driver(drv)) 20488b7381aSBastien Nocera return 0; 20588b7381aSBastien Nocera udrv = to_usb_device_driver(drv); 20688b7381aSBastien Nocera if (udrv == &usb_generic_driver) 20788b7381aSBastien Nocera return 0; 20888b7381aSBastien Nocera if (!udrv->id_table) 20988b7381aSBastien Nocera return 0; 21088b7381aSBastien Nocera 21188b7381aSBastien Nocera return usb_device_match_id(udev, udrv->id_table) != NULL; 21288b7381aSBastien Nocera } 21388b7381aSBastien Nocera 21488b7381aSBastien Nocera static bool usb_generic_driver_match(struct usb_device *udev) 21588b7381aSBastien Nocera { 21688b7381aSBastien Nocera /* 21788b7381aSBastien Nocera * If any other driver wants the device, leave the device to this other 21888b7381aSBastien Nocera * driver. 21988b7381aSBastien Nocera */ 22088b7381aSBastien Nocera if (bus_for_each_drv(&usb_bus_type, NULL, udev, __check_usb_generic)) 22188b7381aSBastien Nocera return false; 22288b7381aSBastien Nocera 22388b7381aSBastien Nocera return true; 22488b7381aSBastien Nocera } 22588b7381aSBastien Nocera 226ef0f7d18SBastien Nocera int usb_generic_driver_probe(struct usb_device *udev) 22736e56a34SAlan Stern { 228782da727SAlan Stern int err, c; 229782da727SAlan Stern 230782da727SAlan Stern /* Choose and set the configuration. This registers the interfaces 231782da727SAlan Stern * with the driver core and lets interface drivers bind to them. 232782da727SAlan Stern */ 233c13b86a3SHindin Joseph if (udev->authorized == 0) 234f8a37464SInaky Perez-Gonzalez dev_err(&udev->dev, "Device is not authorized for usage\n"); 235f8a37464SInaky Perez-Gonzalez else { 236b5ea060fSGreg Kroah-Hartman c = usb_choose_configuration(udev); 237782da727SAlan Stern if (c >= 0) { 238782da727SAlan Stern err = usb_set_configuration(udev, c); 239e9e88fb7SAlan Stern if (err && err != -ENODEV) { 240782da727SAlan Stern dev_err(&udev->dev, "can't set config #%d, error %d\n", 241782da727SAlan Stern c, err); 242782da727SAlan Stern /* This need not be fatal. The user can try to 243782da727SAlan Stern * set other configurations. */ 244782da727SAlan Stern } 245782da727SAlan Stern } 246f8a37464SInaky Perez-Gonzalez } 247782da727SAlan Stern /* USB device state == configured ... usable */ 248782da727SAlan Stern usb_notify_add_device(udev); 249782da727SAlan Stern 25036e56a34SAlan Stern return 0; 25136e56a34SAlan Stern } 252782da727SAlan Stern 253ef0f7d18SBastien Nocera void usb_generic_driver_disconnect(struct usb_device *udev) 25436e56a34SAlan Stern { 255782da727SAlan Stern usb_notify_remove_device(udev); 256782da727SAlan Stern 25736e56a34SAlan Stern /* if this is only an unbind, not a physical disconnect, then 25836e56a34SAlan Stern * unconfigure the device */ 25901d883d4SAlan Stern if (udev->actconfig) 2603f141e2aSAlan Stern usb_set_configuration(udev, -1); 26136e56a34SAlan Stern } 26236e56a34SAlan Stern 263782da727SAlan Stern #ifdef CONFIG_PM 264782da727SAlan Stern 265ef0f7d18SBastien Nocera int usb_generic_driver_suspend(struct usb_device *udev, pm_message_t msg) 266782da727SAlan Stern { 267b6f6436dSAlan Stern int rc; 268b6f6436dSAlan Stern 269686314cfSAlan Stern /* Normal USB devices suspend through their upstream port. 270686314cfSAlan Stern * Root hubs don't have upstream ports to suspend, 271686314cfSAlan Stern * so we have to shut down their downstream HC-to-USB 272686314cfSAlan Stern * interfaces manually by doing a bus (or "global") suspend. 273b6f6436dSAlan Stern */ 274686314cfSAlan Stern if (!udev->parent) 27565bfd296SAlan Stern rc = hcd_bus_suspend(udev, msg); 2765ad4f71eSAlan Stern 27764627388SZhengjun Xing /* 27864627388SZhengjun Xing * Non-root USB2 devices don't need to do anything for FREEZE 27964627388SZhengjun Xing * or PRETHAW. USB3 devices don't support global suspend and 28064627388SZhengjun Xing * needs to be selectively suspended. 28164627388SZhengjun Xing */ 28264627388SZhengjun Xing else if ((msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_PRETHAW) 28364627388SZhengjun Xing && (udev->speed < USB_SPEED_SUPER)) 2845ad4f71eSAlan Stern rc = 0; 285686314cfSAlan Stern else 28665bfd296SAlan Stern rc = usb_port_suspend(udev, msg); 2875ad4f71eSAlan Stern 2887794f486SAlan Stern if (rc == 0) 2897794f486SAlan Stern usbfs_notify_suspend(udev); 290b6f6436dSAlan Stern return rc; 291782da727SAlan Stern } 292782da727SAlan Stern 293ef0f7d18SBastien Nocera int usb_generic_driver_resume(struct usb_device *udev, pm_message_t msg) 294782da727SAlan Stern { 295b6f6436dSAlan Stern int rc; 296b6f6436dSAlan Stern 297686314cfSAlan Stern /* Normal USB devices resume/reset through their upstream port. 298686314cfSAlan Stern * Root hubs don't have upstream ports to resume or reset, 299686314cfSAlan Stern * so we have to start up their downstream HC-to-USB 300686314cfSAlan Stern * interfaces manually by doing a bus (or "global") resume. 301686314cfSAlan Stern */ 302686314cfSAlan Stern if (!udev->parent) 30365bfd296SAlan Stern rc = hcd_bus_resume(udev, msg); 3040458d5b4SAlan Stern else 30565bfd296SAlan Stern rc = usb_port_resume(udev, msg); 3067794f486SAlan Stern 3077794f486SAlan Stern if (rc == 0) 3087794f486SAlan Stern usbfs_notify_resume(udev); 309b6f6436dSAlan Stern return rc; 310782da727SAlan Stern } 311782da727SAlan Stern 312782da727SAlan Stern #endif /* CONFIG_PM */ 313782da727SAlan Stern 3148bb54ab5SAlan Stern struct usb_device_driver usb_generic_driver = { 31536e56a34SAlan Stern .name = "usb", 31688b7381aSBastien Nocera .match = usb_generic_driver_match, 317ef0f7d18SBastien Nocera .probe = usb_generic_driver_probe, 318ef0f7d18SBastien Nocera .disconnect = usb_generic_driver_disconnect, 319782da727SAlan Stern #ifdef CONFIG_PM 320ef0f7d18SBastien Nocera .suspend = usb_generic_driver_suspend, 321ef0f7d18SBastien Nocera .resume = usb_generic_driver_resume, 322782da727SAlan Stern #endif 32301d883d4SAlan Stern .supports_autosuspend = 1, 32436e56a34SAlan Stern }; 325