/** * usb_reset_configuration - lightweight device reset * @dev: the device whose configuration is being reset * * This issues a standard SET_CONFIGURATION request to the device using * the current configuration. The effect is to reset most USB-related * state in the device, including interface altsettings (reset to zero), * endpoint halts (cleared), and data toggle (only for bulk and interrupt * endpoints). Other usbcore state is unchanged, including bindings of * usb device drivers to interfaces. * * Because this affects multiple interfaces, avoid using this with composite * (multi-interface) devices. Instead, the driver for each interface may * use usb_set_interface() on the interfaces it claims. Be careful though; * some devices don't support the SET_INTERFACE request, and others won't * reset all the interface state (notably data toggles). Resetting the whole * configuration would affect other drivers' interfaces. * * The caller must own the device lock. * * Returns zero on success, else a negative error code. */ int usb_reset_configuration(struct usb_device *dev) { int i, retval; struct usb_host_config *config; if (dev->state == USB_STATE_SUSPENDED) return -EHOSTUNREACH; /* caller must have locked the device and must own * the usb bus readlock (so driver bindings are stable); * calls during probe() are fine */ for (i = 1; i < 16; ++i) { usb_disable_endpoint(dev, i); usb_disable_endpoint(dev, i + USB_DIR_IN); } config = dev->actconfig; retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), USB_REQ_SET_CONFIGURATION, 0, config->desc.bConfigurationValue, 0, NULL, 0, USB_CTRL_SET_TIMEOUT); if (retval < 0) return retval; dev->toggle[0] = dev->toggle[1] = 0; /* re-init hc/hcd interface/endpoint state */ for (i = 0; i < config->desc.bNumInterfaces; i++) { struct usb_interface *intf = config->interface[i]; struct usb_host_interface *alt; if (device_is_registered(&intf->dev)) usb_remove_sysfs_intf_files(intf); alt = usb_altnum_to_altsetting(intf, 0); /* No altsetting 0? We'll assume the first altsetting. * We could use a GetInterface call, but if a device is * so non-compliant that it doesn't have altsetting 0 * then I wouldn't trust its reply anyway. */ if (!alt) alt = &intf->altsetting[0]; intf->cur_altsetting = alt; usb_enable_interface(dev, intf); if (device_is_registered(&intf->dev)) usb_create_sysfs_intf_files(intf); } return 0; }
/* * Notifications of device and interface registration */ static int usb_bus_notify(struct notifier_block *nb, unsigned long action, void *data) { struct device *dev = data; switch (action) { case BUS_NOTIFY_ADD_DEVICE: if (dev->type == &usb_device_type) (void) usb_create_sysfs_dev_files(to_usb_device(dev)); else if (dev->type == &usb_if_device_type) usb_create_sysfs_intf_files(to_usb_interface(dev)); break; case BUS_NOTIFY_DEL_DEVICE: if (dev->type == &usb_device_type) usb_remove_sysfs_dev_files(to_usb_device(dev)); else if (dev->type == &usb_if_device_type) usb_remove_sysfs_intf_files(to_usb_interface(dev)); break; } return 0; }
/* * usb_set_configuration - Makes a particular device setting be current * @dev: the device whose configuration is being updated * @configuration: the configuration being chosen. * Context: !in_interrupt(), caller holds dev->serialize * * This is used to enable non-default device modes. Not all devices * use this kind of configurability; many devices only have one * configuration. * * USB device configurations may affect Linux interoperability, * power consumption and the functionality available. For example, * the default configuration is limited to using 100mA of bus power, * so that when certain device functionality requires more power, * and the device is bus powered, that functionality should be in some * non-default device configuration. Other device modes may also be * reflected as configuration options, such as whether two ISDN * channels are available independently; and choosing between open * standard device protocols (like CDC) or proprietary ones. * * Note that USB has an additional level of device configurability, * associated with interfaces. That configurability is accessed using * usb_set_interface(). * * This call is synchronous. The calling context must be able to sleep, * and must not hold the driver model lock for USB; usb device driver * probe() methods may not use this routine. * * Returns zero on success, or else the status code returned by the * underlying call that failed. On succesful completion, each interface * in the original device configuration has been destroyed, and each one * in the new configuration has been probed by all relevant usb device * drivers currently known to the kernel. */ int usb_set_configuration(struct usb_device *dev, int configuration) { int i, ret; struct usb_host_config *cp = NULL; struct usb_interface **new_interfaces = NULL; int n, nintf; /* dev->serialize guards all config changes */ for (i = 0; i < dev->descriptor.bNumConfigurations; i++) { if (dev->config[i].desc.bConfigurationValue == configuration) { cp = &dev->config[i]; break; } } if ((!cp && configuration != 0)) return -EINVAL; /* The USB spec says configuration 0 means unconfigured. * But if a device includes a configuration numbered 0, * we will accept it as a correctly configured state. */ if (cp && configuration == 0) dev_warn(&dev->dev, "config 0 descriptor??\n"); /* Allocate memory for new interfaces before doing anything else, * so that if we run out then nothing will have changed. */ n = nintf = 0; if (cp) { nintf = cp->desc.bNumInterfaces; new_interfaces = kmalloc(nintf * sizeof(*new_interfaces), GFP_KERNEL); if (!new_interfaces) { dev_err(&dev->dev, "Out of memory"); return -ENOMEM; } for (; n < nintf; ++n) { new_interfaces[n] = kmalloc( sizeof(struct usb_interface), GFP_KERNEL); if (!new_interfaces[n]) { dev_err(&dev->dev, "Out of memory"); ret = -ENOMEM; free_interfaces: while (--n >= 0) kfree(new_interfaces[n]); kfree(new_interfaces); return ret; } } } /* if it's already configured, clear out old state first. * getting rid of old interfaces means unbinding their drivers. */ if (dev->state != USB_STATE_ADDRESS) usb_disable_device (dev, 1); // Skip ep0 if ((ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), USB_REQ_SET_CONFIGURATION, 0, configuration, 0, NULL, 0, HZ * USB_CTRL_SET_TIMEOUT)) < 0) goto free_interfaces; dev->actconfig = cp; if (!cp) usb_set_device_state(dev, USB_STATE_ADDRESS); else { usb_set_device_state(dev, USB_STATE_CONFIGURED); /*Êý¾Ý¿¨²åÈëÍø¹Ø¼ì²âl65130 2008-09-20 start*/ if (0x12d1 == dev->descriptor.idVendor && !g_iDataCardIn) { g_iDataCardIn = 1; } /*Êý¾Ý¿¨²åÈëÍø¹Ø¼ì²âl65130 2008-09-20 end*/ /* Initialize the new interface structures and the * hc/hcd/usbcore interface/endpoint state. */ for (i = 0; i < nintf; ++i) { struct usb_interface_cache *intfc; struct usb_interface *intf; struct usb_host_interface *alt; cp->interface[i] = intf = new_interfaces[i]; memset(intf, 0, sizeof(*intf)); intfc = cp->intf_cache[i]; intf->altsetting = intfc->altsetting; intf->num_altsetting = intfc->num_altsetting; kref_get(&intfc->ref); alt = usb_altnum_to_altsetting(intf, 0); /* No altsetting 0? We'll assume the first altsetting. * We could use a GetInterface call, but if a device is * so non-compliant that it doesn't have altsetting 0 * then I wouldn't trust its reply anyway. */ if (!alt) alt = &intf->altsetting[0]; intf->cur_altsetting = alt; usb_enable_interface(dev, intf); intf->dev.parent = &dev->dev; intf->dev.driver = NULL; intf->dev.bus = &usb_bus_type; intf->dev.dma_mask = dev->dev.dma_mask; intf->dev.release = release_interface; device_initialize (&intf->dev); sprintf (&intf->dev.bus_id[0], "%d-%s:%d.%d", dev->bus->busnum, dev->devpath, configuration, alt->desc.bInterfaceNumber); } kfree(new_interfaces); /* Now that all the interfaces are set up, register them * to trigger binding of drivers to interfaces. probe() * routines may install different altsettings and may * claim() any interfaces not yet bound. Many class drivers * need that: CDC, audio, video, etc. */ for (i = 0; i < nintf; ++i) { struct usb_interface *intf = cp->interface[i]; struct usb_interface_descriptor *desc; desc = &intf->altsetting [0].desc; dev_dbg (&dev->dev, "adding %s (config #%d, interface %d)\n", intf->dev.bus_id, configuration, desc->bInterfaceNumber); ret = device_add (&intf->dev); if (ret != 0) { dev_err(&dev->dev, "device_add(%s) --> %d\n", intf->dev.bus_id, ret); continue; } usb_create_sysfs_intf_files (intf); } } return ret; }
/* * usb_set_configuration - Makes a particular device setting be current * @dev: the device whose configuration is being updated * @configuration: the configuration being chosen. * Context: !in_interrupt(), caller owns the device lock * * This is used to enable non-default device modes. Not all devices * use this kind of configurability; many devices only have one * configuration. * * @configuration is the value of the configuration to be installed. * According to the USB spec (e.g. section 9.1.1.5), configuration values * must be non-zero; a value of zero indicates that the device in * unconfigured. However some devices erroneously use 0 as one of their * configuration values. To help manage such devices, this routine will * accept @configuration = -1 as indicating the device should be put in * an unconfigured state. * * USB device configurations may affect Linux interoperability, * power consumption and the functionality available. For example, * the default configuration is limited to using 100mA of bus power, * so that when certain device functionality requires more power, * and the device is bus powered, that functionality should be in some * non-default device configuration. Other device modes may also be * reflected as configuration options, such as whether two ISDN * channels are available independently; and choosing between open * standard device protocols (like CDC) or proprietary ones. * * Note that USB has an additional level of device configurability, * associated with interfaces. That configurability is accessed using * usb_set_interface(). * * This call is synchronous. The calling context must be able to sleep, * must own the device lock, and must not hold the driver model's USB * bus rwsem; usb device driver probe() methods cannot use this routine. * * Returns zero on success, or else the status code returned by the * underlying call that failed. On successful completion, each interface * in the original device configuration has been destroyed, and each one * in the new configuration has been probed by all relevant usb device * drivers currently known to the kernel. */ int usb_set_configuration(struct usb_device *dev, int configuration) { int i, ret; struct usb_host_config *cp = NULL; struct usb_interface **new_interfaces = NULL; int n, nintf; if (configuration == -1) configuration = 0; else { for (i = 0; i < dev->descriptor.bNumConfigurations; i++) { if (dev->config[i].desc.bConfigurationValue == configuration) { cp = &dev->config[i]; break; } } } if ((!cp && configuration != 0)) return -EINVAL; /* The USB spec says configuration 0 means unconfigured. * But if a device includes a configuration numbered 0, * we will accept it as a correctly configured state. * Use -1 if you really want to unconfigure the device. */ if (cp && configuration == 0) dev_warn(&dev->dev, "config 0 descriptor??\n"); /* Allocate memory for new interfaces before doing anything else, * so that if we run out then nothing will have changed. */ n = nintf = 0; if (cp) { nintf = cp->desc.bNumInterfaces; new_interfaces = kmalloc(nintf * sizeof(*new_interfaces), GFP_KERNEL); if (!new_interfaces) { dev_err(&dev->dev, "Out of memory"); return -ENOMEM; } for (; n < nintf; ++n) { new_interfaces[n] = kzalloc( sizeof(struct usb_interface), GFP_KERNEL); if (!new_interfaces[n]) { dev_err(&dev->dev, "Out of memory"); ret = -ENOMEM; free_interfaces: while (--n >= 0) kfree(new_interfaces[n]); kfree(new_interfaces); return ret; } } i = dev->bus_mA - cp->desc.bMaxPower * 2; if (i < 0) dev_warn(&dev->dev, "new config #%d exceeds power " "limit by %dmA\n", configuration, -i); } /* Wake up the device so we can send it the Set-Config request */ ret = usb_autoresume_device(dev); if (ret) goto free_interfaces; /* if it's already configured, clear out old state first. * getting rid of old interfaces means unbinding their drivers. */ if (dev->state != USB_STATE_ADDRESS) usb_disable_device (dev, 1); // Skip ep0 if ((ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), USB_REQ_SET_CONFIGURATION, 0, configuration, 0, NULL, 0, USB_CTRL_SET_TIMEOUT)) < 0) { /* All the old state is gone, so what else can we do? * The device is probably useless now anyway. */ cp = NULL; } dev->actconfig = cp; if (!cp) { usb_set_device_state(dev, USB_STATE_ADDRESS); usb_autosuspend_device(dev); goto free_interfaces; } usb_set_device_state(dev, USB_STATE_CONFIGURED); /* Initialize the new interface structures and the * hc/hcd/usbcore interface/endpoint state. */ for (i = 0; i < nintf; ++i) { struct usb_interface_cache *intfc; struct usb_interface *intf; struct usb_host_interface *alt; cp->interface[i] = intf = new_interfaces[i]; intfc = cp->intf_cache[i]; intf->altsetting = intfc->altsetting; intf->num_altsetting = intfc->num_altsetting; kref_get(&intfc->ref); alt = usb_altnum_to_altsetting(intf, 0); /* No altsetting 0? We'll assume the first altsetting. * We could use a GetInterface call, but if a device is * so non-compliant that it doesn't have altsetting 0 * then I wouldn't trust its reply anyway. */ if (!alt) alt = &intf->altsetting[0]; intf->cur_altsetting = alt; usb_enable_interface(dev, intf); intf->dev.parent = &dev->dev; intf->dev.driver = NULL; intf->dev.bus = &usb_bus_type; intf->dev.dma_mask = dev->dev.dma_mask; intf->dev.release = release_interface; device_initialize (&intf->dev); mark_quiesced(intf); sprintf (&intf->dev.bus_id[0], "%d-%s:%d.%d", dev->bus->busnum, dev->devpath, configuration, alt->desc.bInterfaceNumber); } kfree(new_interfaces); if (cp->string == NULL) cp->string = usb_cache_string(dev, cp->desc.iConfiguration); /* Now that all the interfaces are set up, register them * to trigger binding of drivers to interfaces. probe() * routines may install different altsettings and may * claim() any interfaces not yet bound. Many class drivers * need that: CDC, audio, video, etc. */ for (i = 0; i < nintf; ++i) { struct usb_interface *intf = cp->interface[i]; dev_dbg (&dev->dev, "adding %s (config #%d, interface %d)\n", intf->dev.bus_id, configuration, intf->cur_altsetting->desc.bInterfaceNumber); ret = device_add (&intf->dev); if (ret != 0) { dev_err(&dev->dev, "device_add(%s) --> %d\n", intf->dev.bus_id, ret); continue; } usb_create_sysfs_intf_files (intf); } usb_autosuspend_device(dev); return 0; }
/** * usb_set_interface - Makes a particular alternate setting be current * @dev: the device whose interface is being updated * @interface: the interface being updated * @alternate: the setting being chosen. * Context: !in_interrupt () * * This is used to enable data transfers on interfaces that may not * be enabled by default. Not all devices support such configurability. * Only the driver bound to an interface may change its setting. * * Within any given configuration, each interface may have several * alternative settings. These are often used to control levels of * bandwidth consumption. For example, the default setting for a high * speed interrupt endpoint may not send more than 64 bytes per microframe, * while interrupt transfers of up to 3KBytes per microframe are legal. * Also, isochronous endpoints may never be part of an * interface's default setting. To access such bandwidth, alternate * interface settings must be made current. * * Note that in the Linux USB subsystem, bandwidth associated with * an endpoint in a given alternate setting is not reserved until an URB * is submitted that needs that bandwidth. Some other operating systems * allocate bandwidth early, when a configuration is chosen. * * This call is synchronous, and may not be used in an interrupt context. * Also, drivers must not change altsettings while urbs are scheduled for * endpoints in that interface; all such urbs must first be completed * (perhaps forced by unlinking). * * Returns zero on success, or else the status code returned by the * underlying usb_control_msg() call. */ int usb_set_interface(struct usb_device *dev, int interface, int alternate) { struct usb_interface *iface; struct usb_host_interface *alt; int ret; int manual = 0; if (dev->state == USB_STATE_SUSPENDED) return -EHOSTUNREACH; iface = usb_ifnum_to_if(dev, interface); if (!iface) { dev_dbg(&dev->dev, "selecting invalid interface %d\n", interface); return -EINVAL; } alt = usb_altnum_to_altsetting(iface, alternate); if (!alt) { warn("selecting invalid altsetting %d", alternate); return -EINVAL; } ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), USB_REQ_SET_INTERFACE, USB_RECIP_INTERFACE, alternate, interface, NULL, 0, 5000); /* 9.4.10 says devices don't need this and are free to STALL the * request if the interface only has one alternate setting. */ if (ret == -EPIPE && iface->num_altsetting == 1) { dev_dbg(&dev->dev, "manual set_interface for iface %d, alt %d\n", interface, alternate); manual = 1; } else if (ret < 0) return ret; /* FIXME drivers shouldn't need to replicate/bugfix the logic here * when they implement async or easily-killable versions of this or * other "should-be-internal" functions (like clear_halt). * should hcd+usbcore postprocess control requests? */ /* prevent submissions using previous endpoint settings */ if (device_is_registered(&iface->dev)) usb_remove_sysfs_intf_files(iface); usb_disable_interface(dev, iface); iface->cur_altsetting = alt; /* If the interface only has one altsetting and the device didn't * accept the request, we attempt to carry out the equivalent action * by manually clearing the HALT feature for each endpoint in the * new altsetting. */ if (manual) { int i; for (i = 0; i < alt->desc.bNumEndpoints; i++) { unsigned int epaddr = alt->endpoint[i].desc.bEndpointAddress; unsigned int pipe = __create_pipe(dev, USB_ENDPOINT_NUMBER_MASK & epaddr) | (usb_endpoint_out(epaddr) ? USB_DIR_OUT : USB_DIR_IN); usb_clear_halt(dev, pipe); } } /* 9.1.1.5: reset toggles for all endpoints in the new altsetting * * Note: * Despite EP0 is always present in all interfaces/AS, the list of * endpoints from the descriptor does not contain EP0. Due to its * omnipresence one might expect EP0 being considered "affected" by * any SetInterface request and hence assume toggles need to be reset. * However, EP0 toggles are re-synced for every individual transfer * during the SETUP stage - hence EP0 toggles are "don't care" here. * (Likewise, EP0 never "halts" on well designed devices.) */ usb_enable_interface(dev, iface); if (device_is_registered(&iface->dev)) usb_create_sysfs_intf_files(iface); return 0; }
/**ltl 功能:设置usb设备的配置,并且加载与接口相关的驱动程序 参数:dev ->usb设备 configuration ->usb配置编号 返回值: 说明:调用这个接口,usb设备才会进入配置阶段 */ int usb_set_configuration(struct usb_device *dev, int configuration) { int i, ret; struct usb_host_config *cp = NULL; struct usb_interface **new_interfaces = NULL; int n, nintf; for (i = 0; i < dev->descriptor.bNumConfigurations; i++) { if (dev->config[i].desc.bConfigurationValue == configuration) { cp = &dev->config[i]; break; } } if ((!cp && configuration != 0)) return -EINVAL; /* The USB spec says configuration 0 means unconfigured. * But if a device includes a configuration numbered 0, * we will accept it as a correctly configured state. */ if (cp && configuration == 0) dev_warn(&dev->dev, "config 0 descriptor??\n"); if (dev->state == USB_STATE_SUSPENDED) return -EHOSTUNREACH; /* Allocate memory for new interfaces before doing anything else, * so that if we run out then nothing will have changed. */ n = nintf = 0; if (cp) { nintf = cp->desc.bNumInterfaces;//接口数量 new_interfaces = kmalloc(nintf * sizeof(*new_interfaces), GFP_KERNEL); if (!new_interfaces) { dev_err(&dev->dev, "Out of memory"); return -ENOMEM; } for (; n < nintf; ++n) { new_interfaces[n] = kzalloc( sizeof(struct usb_interface), GFP_KERNEL); if (!new_interfaces[n]) { dev_err(&dev->dev, "Out of memory"); ret = -ENOMEM; free_interfaces: while (--n >= 0) kfree(new_interfaces[n]); kfree(new_interfaces); return ret; } } i = dev->bus_mA - cp->desc.bMaxPower * 2; if (i < 0) dev_warn(&dev->dev, "new config #%d exceeds power " "limit by %dmA\n", configuration, -i); } /* if it's already configured, clear out old state first. * getting rid of old interfaces means unbinding their drivers. */ if (dev->state != USB_STATE_ADDRESS) usb_disable_device (dev, 1); // Skip ep0 //设置配置编号 if ((ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), USB_REQ_SET_CONFIGURATION, 0, configuration, 0, NULL, 0, USB_CTRL_SET_TIMEOUT)) < 0) { /* All the old state is gone, so what else can we do? * The device is probably useless now anyway. */ cp = NULL; } //当前的配置对象 dev->actconfig = cp; if (!cp) { usb_set_device_state(dev, USB_STATE_ADDRESS); goto free_interfaces; } usb_set_device_state(dev, USB_STATE_CONFIGURED); /* Initialize the new interface structures and the * hc/hcd/usbcore interface/endpoint state. */ //对interface对象赋值 for (i = 0; i < nintf; ++i) { struct usb_interface_cache *intfc; struct usb_interface *intf; struct usb_host_interface *alt; cp->interface[i] = intf = new_interfaces[i]; intfc = cp->intf_cache[i]; intf->altsetting = intfc->altsetting; intf->num_altsetting = intfc->num_altsetting; kref_get(&intfc->ref); alt = usb_altnum_to_altsetting(intf, 0); /* No altsetting 0? We'll assume the first altsetting. * We could use a GetInterface call, but if a device is * so non-compliant that it doesn't have altsetting 0 * then I wouldn't trust its reply anyway. */ if (!alt) alt = &intf->altsetting[0]; intf->cur_altsetting = alt; usb_enable_interface(dev, intf); intf->dev.parent = &dev->dev; intf->dev.driver = NULL; /*总线驱动模型中,interface作为设备,如果interface是一个usb hub(bInterfaceClass=9),则按总线驱动模型,就会匹配hub_driver驱动,调用device_add后, 最后调用hub_probe,去 分配usb_hub对象,并为每个hub关联中断处理函数,当hub端口中有设备插入时,hub产生 一中断hub_irq,最终唤醒线程hub_thread,然后为usb设备分配设备号(hub_port_connect_change) ;如果interface是一个usb设备(bInterfaceClass=x),比如:usbmouse,此时会去匹配usb_mouse_driver。 */ intf->dev.bus = &usb_bus_type; intf->dev.dma_mask = dev->dev.dma_mask; intf->dev.release = release_interface; device_initialize (&intf->dev); mark_quiesced(intf); sprintf (&intf->dev.bus_id[0], "%d-%s:%d.%d", dev->bus->busnum, dev->devpath, configuration, alt->desc.bInterfaceNumber); } kfree(new_interfaces); if (cp->string == NULL) cp->string = usb_cache_string(dev, cp->desc.iConfiguration); /* Now that all the interfaces are set up, register them * to trigger binding of drivers to interfaces. probe() * routines may install different altsettings and may * claim() any interfaces not yet bound. Many class drivers * need that: CDC, audio, video, etc. */ /*每个接口代表一个功能,每个接口都有一个驱动程序,载之*/ for (i = 0; i < nintf; ++i) { struct usb_interface *intf = cp->interface[i]; dev_dbg (&dev->dev, "adding %s (config #%d, interface %d)\n", intf->dev.bus_id, configuration, intf->cur_altsetting->desc.bInterfaceNumber); //执行后,设备驱动将执行探针接口:hub_probe,storage_probe ret = device_add (&intf->dev); if (ret != 0) { dev_err(&dev->dev, "device_add(%s) --> %d\n", intf->dev.bus_id, ret); continue; } usb_create_sysfs_intf_files (intf); } return 0; }