OSCL-LXR linux-6.0.1/​drivers/​usb/​gadget/​composite.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * composite.c - infrastructure for Composite USB Gadgets
  *
  * Copyright (C) 2006-2008 David Brownell
  */
 
 /* #define VERBOSE_DEBUG */
 
 #include <linux/kallsyms.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/device.h>
 #include <linux/utsname.h>
 #include <linux/bitfield.h>
 
 #include <linux/usb/composite.h>
 #include <linux/usb/otg.h>
 #include <asm/unaligned.h>
 
 #include "u_os_desc.h"
 
 /**
  * struct usb_os_string - represents OS String to be reported by a gadget
  * @bLength: total length of the entire descritor, always 0x12
  * @bDescriptorType: USB_DT_STRING
  * @qwSignature: the OS String proper
  * @bMS_VendorCode: code used by the host for subsequent requests
  * @bPad: not used, must be zero
  */
 struct usb_os_string {
     __u8    bLength;
     __u8    bDescriptorType;
     __u8    qwSignature[OS_STRING_QW_SIGN_LEN];
     __u8    bMS_VendorCode;
     __u8    bPad;
 } __packed;
 
 /*
  * The code in this file is utility code, used to build a gadget driver
  * from one or more "function" drivers, one or more "configuration"
  * objects, and a "usb_composite_driver" by gluing them together along
  * with the relevant device-wide data.
  */
 
 static struct usb_gadget_strings **get_containers_gs(
         struct usb_gadget_string_container *uc)
 {
     return (struct usb_gadget_strings **)uc->stash;
 }
 
 /**
  * function_descriptors() - get function descriptors for speed
  * @f: the function
  * @speed: the speed
  *
  * Returns the descriptors or NULL if not set.
  */
 static struct usb_descriptor_header **
 function_descriptors(struct usb_function *f,
              enum usb_device_speed speed)
 {
     struct usb_descriptor_header **descriptors;
 
     /*
      * NOTE: we try to help gadget drivers which might not be setting
      * max_speed appropriately.
      */
 
     switch (speed) {
     case USB_SPEED_SUPER_PLUS:
         descriptors = f->ssp_descriptors;
         if (descriptors)
             break;
         fallthrough;
     case USB_SPEED_SUPER:
         descriptors = f->ss_descriptors;
         if (descriptors)
             break;
         fallthrough;
     case USB_SPEED_HIGH:
         descriptors = f->hs_descriptors;
         if (descriptors)
             break;
         fallthrough;
     default:
         descriptors = f->fs_descriptors;
     }
 
     /*
      * if we can't find any descriptors at all, then this gadget deserves to
      * Oops with a NULL pointer dereference
      */
 
     return descriptors;
 }
 
 /**
  * next_desc() - advance to the next desc_type descriptor
  * @t: currect pointer within descriptor array
  * @desc_type: descriptor type
  *
  * Return: next desc_type descriptor or NULL
  *
  * Iterate over @t until either desc_type descriptor found or
  * NULL (that indicates end of list) encountered
  */
 static struct usb_descriptor_header**
 next_desc(struct usb_descriptor_header **t, u8 desc_type)
 {
     for (; *t; t++) {
         if ((*t)->bDescriptorType == desc_type)
             return t;
     }
     return NULL;
 }
 
 /*
  * for_each_desc() - iterate over desc_type descriptors in the
  * descriptors list
  * @start: pointer within descriptor array.
  * @iter_desc: desc_type descriptor to use as the loop cursor
  * @desc_type: wanted descriptr type
  */
 #define for_each_desc(start, iter_desc, desc_type) \
     for (iter_desc = next_desc(start, desc_type); \
          iter_desc; iter_desc = next_desc(iter_desc + 1, desc_type))
 
 /**
  * config_ep_by_speed_and_alt() - configures the given endpoint
  * according to gadget speed.
  * @g: pointer to the gadget
  * @f: usb function
  * @_ep: the endpoint to configure
  * @alt: alternate setting number
  *
  * Return: error code, 0 on success
  *
  * This function chooses the right descriptors for a given
  * endpoint according to gadget speed and saves it in the
  * endpoint desc field. If the endpoint already has a descriptor
  * assigned to it - overwrites it with currently corresponding
  * descriptor. The endpoint maxpacket field is updated according
  * to the chosen descriptor.
  * Note: the supplied function should hold all the descriptors
  * for supported speeds
  */
 int config_ep_by_speed_and_alt(struct usb_gadget *g,
                 struct usb_function *f,
                 struct usb_ep *_ep,
                 u8 alt)
 {
     struct usb_endpoint_descriptor *chosen_desc = NULL;
     struct usb_interface_descriptor *int_desc = NULL;
     struct usb_descriptor_header **speed_desc = NULL;
 
     struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
     int want_comp_desc = 0;
 
     struct usb_descriptor_header **d_spd; /* cursor for speed desc */
     struct usb_composite_dev *cdev;
     bool incomplete_desc = false;
 
     if (!g || !f || !_ep)
         return -EIO;
 
     /* select desired speed */
     switch (g->speed) {
     case USB_SPEED_SUPER_PLUS:
         if (gadget_is_superspeed_plus(g)) {
             if (f->ssp_descriptors) {
                 speed_desc = f->ssp_descriptors;
                 want_comp_desc = 1;
                 break;
             }
             incomplete_desc = true;
         }
         fallthrough;
     case USB_SPEED_SUPER:
         if (gadget_is_superspeed(g)) {
             if (f->ss_descriptors) {
                 speed_desc = f->ss_descriptors;
                 want_comp_desc = 1;
                 break;
             }
             incomplete_desc = true;
         }
         fallthrough;
     case USB_SPEED_HIGH:
         if (gadget_is_dualspeed(g)) {
             if (f->hs_descriptors) {
                 speed_desc = f->hs_descriptors;
                 break;
             }
             incomplete_desc = true;
         }
         fallthrough;
     default:
         speed_desc = f->fs_descriptors;
     }
 
     cdev = get_gadget_data(g);
     if (incomplete_desc)
         WARNING(cdev,
             "%s doesn't hold the descriptors for current speed\n",
             f->name);
 
     /* find correct alternate setting descriptor */
     for_each_desc(speed_desc, d_spd, USB_DT_INTERFACE) {
         int_desc = (struct usb_interface_descriptor *)*d_spd;
 
         if (int_desc->bAlternateSetting == alt) {
             speed_desc = d_spd;
             goto intf_found;
         }
     }
     return -EIO;
 
 intf_found:
     /* find descriptors */
     for_each_desc(speed_desc, d_spd, USB_DT_ENDPOINT) {
         chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
         if (chosen_desc->bEndpointAddress == _ep->address)
             goto ep_found;
     }
     return -EIO;
 
 ep_found:
     /* commit results */
     _ep->maxpacket = usb_endpoint_maxp(chosen_desc);
     _ep->desc = chosen_desc;
     _ep->comp_desc = NULL;
     _ep->maxburst = 0;
     _ep->mult = 1;
 
     if (g->speed == USB_SPEED_HIGH && (usb_endpoint_xfer_isoc(_ep->desc) ||
                 usb_endpoint_xfer_int(_ep->desc)))
         _ep->mult = usb_endpoint_maxp_mult(_ep->desc);
 
     if (!want_comp_desc)
         return 0;
 
     /*
      * Companion descriptor should follow EP descriptor
      * USB 3.0 spec, #9.6.7
      */
     comp_desc = (struct usb_ss_ep_comp_descriptor *)*(++d_spd);
     if (!comp_desc ||
         (comp_desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP))
         return -EIO;
     _ep->comp_desc = comp_desc;
     if (g->speed >= USB_SPEED_SUPER) {
         switch (usb_endpoint_type(_ep->desc)) {
         case USB_ENDPOINT_XFER_ISOC:
             /* mult: bits 1:0 of bmAttributes */
             _ep->mult = (comp_desc->bmAttributes & 0x3) + 1;
             fallthrough;
         case USB_ENDPOINT_XFER_BULK:
         case USB_ENDPOINT_XFER_INT:
             _ep->maxburst = comp_desc->bMaxBurst + 1;
             break;
         default:
             if (comp_desc->bMaxBurst != 0)
                 ERROR(cdev, "ep0 bMaxBurst must be 0\n");
             _ep->maxburst = 1;
             break;
         }
     }
     return 0;
 }
 EXPORT_SYMBOL_GPL(config_ep_by_speed_and_alt);
 
 /**
  * config_ep_by_speed() - configures the given endpoint
  * according to gadget speed.
  * @g: pointer to the gadget
  * @f: usb function
  * @_ep: the endpoint to configure
  *
  * Return: error code, 0 on success
  *
  * This function chooses the right descriptors for a given
  * endpoint according to gadget speed and saves it in the
  * endpoint desc field. If the endpoint already has a descriptor
  * assigned to it - overwrites it with currently corresponding
  * descriptor. The endpoint maxpacket field is updated according
  * to the chosen descriptor.
  * Note: the supplied function should hold all the descriptors
  * for supported speeds
  */
 int config_ep_by_speed(struct usb_gadget *g,
             struct usb_function *f,
             struct usb_ep *_ep)
 {
     return config_ep_by_speed_and_alt(g, f, _ep, 0);
 }
 EXPORT_SYMBOL_GPL(config_ep_by_speed);
 
 /**
  * usb_add_function() - add a function to a configuration
  * @config: the configuration
  * @function: the function being added
  * Context: single threaded during gadget setup
  *
  * After initialization, each configuration must have one or more
  * functions added to it.  Adding a function involves calling its @bind()
  * method to allocate resources such as interface and string identifiers
  * and endpoints.
  *
  * This function returns the value of the function's bind(), which is
  * zero for success else a negative errno value.
  */
 int usb_add_function(struct usb_configuration *config,
         struct usb_function *function)
 {
     int value = -EINVAL;
 
     DBG(config->cdev, "adding '%s'/%p to config '%s'/%p\n",
             function->name, function,
             config->label, config);
 
     if (!function->set_alt || !function->disable)
         goto done;
 
     function->config = config;
     list_add_tail(&function->list, &config->functions);
 
     if (function->bind_deactivated) {
         value = usb_function_deactivate(function);
         if (value)
             goto done;
     }
 
     /* REVISIT *require* function->bind? */
     if (function->bind) {
         value = function->bind(config, function);
         if (value < 0) {
             list_del(&function->list);
             function->config = NULL;
         }
     } else
         value = 0;
 
     /* We allow configurations that don't work at both speeds.
      * If we run into a lowspeed Linux system, treat it the same
      * as full speed ... it's the function drivers that will need
      * to avoid bulk and ISO transfers.
      */
     if (!config->fullspeed && function->fs_descriptors)
         config->fullspeed = true;
     if (!config->highspeed && function->hs_descriptors)
         config->highspeed = true;
     if (!config->superspeed && function->ss_descriptors)
         config->superspeed = true;
     if (!config->superspeed_plus && function->ssp_descriptors)
         config->superspeed_plus = true;
 
 done:
     if (value)
         DBG(config->cdev, "adding '%s'/%p --> %d\n",
                 function->name, function, value);
     return value;
 }
 EXPORT_SYMBOL_GPL(usb_add_function);
 
 void usb_remove_function(struct usb_configuration *c, struct usb_function *f)
 {
     if (f->disable)
         f->disable(f);
 
     bitmap_zero(f->endpoints, 32);
     list_del(&f->list);
     if (f->unbind)
         f->unbind(c, f);
 
     if (f->bind_deactivated)
         usb_function_activate(f);
 }
 EXPORT_SYMBOL_GPL(usb_remove_function);
 
 /**
  * usb_function_deactivate - prevent function and gadget enumeration
  * @function: the function that isn't yet ready to respond
  *
  * Blocks response of the gadget driver to host enumeration by
  * preventing the data line pullup from being activated.  This is
  * normally called during @bind() processing to change from the
  * initial "ready to respond" state, or when a required resource
  * becomes available.
  *
  * For example, drivers that serve as a passthrough to a userspace
  * daemon can block enumeration unless that daemon (such as an OBEX,
  * MTP, or print server) is ready to handle host requests.
  *
  * Not all systems support software control of their USB peripheral
  * data pullups.
  *
  * Returns zero on success, else negative errno.
  */
 int usb_function_deactivate(struct usb_function *function)
 {
     struct usb_composite_dev    *cdev = function->config->cdev;
     unsigned long           flags;
     int             status = 0;
 
     spin_lock_irqsave(&cdev->lock, flags);
 
     if (cdev->deactivations == 0) {
         spin_unlock_irqrestore(&cdev->lock, flags);
         status = usb_gadget_deactivate(cdev->gadget);
         spin_lock_irqsave(&cdev->lock, flags);
     }
     if (status == 0)
         cdev->deactivations++;
 
     spin_unlock_irqrestore(&cdev->lock, flags);
     return status;
 }
 EXPORT_SYMBOL_GPL(usb_function_deactivate);
 
 /**
  * usb_function_activate - allow function and gadget enumeration
  * @function: function on which usb_function_activate() was called
  *
  * Reverses effect of usb_function_deactivate().  If no more functions
  * are delaying their activation, the gadget driver will respond to
  * host enumeration procedures.
  *
  * Returns zero on success, else negative errno.
  */
 int usb_function_activate(struct usb_function *function)
 {
     struct usb_composite_dev    *cdev = function->config->cdev;
     unsigned long           flags;
     int             status = 0;
 
     spin_lock_irqsave(&cdev->lock, flags);
 
     if (WARN_ON(cdev->deactivations == 0))
         status = -EINVAL;
     else {
         cdev->deactivations--;
         if (cdev->deactivations == 0) {
             spin_unlock_irqrestore(&cdev->lock, flags);
             status = usb_gadget_activate(cdev->gadget);
             spin_lock_irqsave(&cdev->lock, flags);
         }
     }
 
     spin_unlock_irqrestore(&cdev->lock, flags);
     return status;
 }
 EXPORT_SYMBOL_GPL(usb_function_activate);
 
 /**
  * usb_interface_id() - allocate an unused interface ID
  * @config: configuration associated with the interface
  * @function: function handling the interface
  * Context: single threaded during gadget setup
  *
  * usb_interface_id() is called from usb_function.bind() callbacks to
  * allocate new interface IDs.  The function driver will then store that
  * ID in interface, association, CDC union, and other descriptors.  It
  * will also handle any control requests targeted at that interface,
  * particularly changing its altsetting via set_alt().  There may
  * also be class-specific or vendor-specific requests to handle.
  *
  * All interface identifier should be allocated using this routine, to
  * ensure that for example different functions don't wrongly assign
  * different meanings to the same identifier.  Note that since interface
  * identifiers are configuration-specific, functions used in more than
  * one configuration (or more than once in a given configuration) need
  * multiple versions of the relevant descriptors.
  *
  * Returns the interface ID which was allocated; or -ENODEV if no
  * more interface IDs can be allocated.
  */
 int usb_interface_id(struct usb_configuration *config,
         struct usb_function *function)
 {
     unsigned id = config->next_interface_id;
 
     if (id < MAX_CONFIG_INTERFACES) {
         config->interface[id] = function;
         config->next_interface_id = id + 1;
         return id;
     }
     return -ENODEV;
 }
 EXPORT_SYMBOL_GPL(usb_interface_id);
 
 static u8 encode_bMaxPower(enum usb_device_speed speed,
         struct usb_configuration *c)
 {
     unsigned val;
 
     if (c->MaxPower || (c->bmAttributes & USB_CONFIG_ATT_SELFPOWER))
         val = c->MaxPower;
     else
         val = CONFIG_USB_GADGET_VBUS_DRAW;
     if (!val)
         return 0;
     if (speed < USB_SPEED_SUPER)
         return min(val, 500U) / 2;
     else
         /*
          * USB 3.x supports up to 900mA, but since 900 isn't divisible
          * by 8 the integral division will effectively cap to 896mA.
          */
         return min(val, 900U) / 8;
 }
 
 static int config_buf(struct usb_configuration *config,
         enum usb_device_speed speed, void *buf, u8 type)
 {
     struct usb_config_descriptor    *c = buf;
     void                *next = buf + USB_DT_CONFIG_SIZE;
     int             len;
     struct usb_function     *f;
     int             status;
 
     len = USB_COMP_EP0_BUFSIZ - USB_DT_CONFIG_SIZE;
     /* write the config descriptor */
     c = buf;
     c->bLength = USB_DT_CONFIG_SIZE;
     c->bDescriptorType = type;
     /* wTotalLength is written later */
     c->bNumInterfaces = config->next_interface_id;
     c->bConfigurationValue = config->bConfigurationValue;
     c->iConfiguration = config->iConfiguration;
     c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
     c->bMaxPower = encode_bMaxPower(speed, config);
 
     /* There may be e.g. OTG descriptors */
     if (config->descriptors) {
         status = usb_descriptor_fillbuf(next, len,
                 config->descriptors);
         if (status < 0)
             return status;
         len -= status;
         next += status;
     }
 
     /* add each function's descriptors */
     list_for_each_entry(f, &config->functions, list) {
         struct usb_descriptor_header **descriptors;
 
         descriptors = function_descriptors(f, speed);
         if (!descriptors)
             continue;
         status = usb_descriptor_fillbuf(next, len,
             (const struct usb_descriptor_header **) descriptors);
         if (status < 0)
             return status;
         len -= status;
         next += status;
     }
 
     len = next - buf;
     c->wTotalLength = cpu_to_le16(len);
     return len;
 }
 
 static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
 {
     struct usb_gadget       *gadget = cdev->gadget;
     struct usb_configuration    *c;
     struct list_head        *pos;
     u8              type = w_value >> 8;
     enum usb_device_speed       speed = USB_SPEED_UNKNOWN;
 
     if (gadget->speed >= USB_SPEED_SUPER)
         speed = gadget->speed;
     else if (gadget_is_dualspeed(gadget)) {
         int hs = 0;
         if (gadget->speed == USB_SPEED_HIGH)
             hs = 1;
         if (type == USB_DT_OTHER_SPEED_CONFIG)
             hs = !hs;
         if (hs)
             speed = USB_SPEED_HIGH;
 
     }
 
     /* This is a lookup by config *INDEX* */
     w_value &= 0xff;
 
     pos = &cdev->configs;
     c = cdev->os_desc_config;
     if (c)
         goto check_config;
 
     while ((pos = pos->next) !=  &cdev->configs) {
         c = list_entry(pos, typeof(*c), list);
 
         /* skip OS Descriptors config which is handled separately */
         if (c == cdev->os_desc_config)
             continue;
 
 check_config:
         /* ignore configs that won't work at this speed */
         switch (speed) {
         case USB_SPEED_SUPER_PLUS:
             if (!c->superspeed_plus)
                 continue;
             break;
         case USB_SPEED_SUPER:
             if (!c->superspeed)
                 continue;
             break;
         case USB_SPEED_HIGH:
             if (!c->highspeed)
                 continue;
             break;
         default:
             if (!c->fullspeed)
                 continue;
         }
 
         if (w_value == 0)
             return config_buf(c, speed, cdev->req->buf, type);
         w_value--;
     }
     return -EINVAL;
 }
 
 static int count_configs(struct usb_composite_dev *cdev, unsigned type)
 {
     struct usb_gadget       *gadget = cdev->gadget;
     struct usb_configuration    *c;
     unsigned            count = 0;
     int             hs = 0;
     int             ss = 0;
     int             ssp = 0;
 
     if (gadget_is_dualspeed(gadget)) {
         if (gadget->speed == USB_SPEED_HIGH)
             hs = 1;
         if (gadget->speed == USB_SPEED_SUPER)
             ss = 1;
         if (gadget->speed == USB_SPEED_SUPER_PLUS)
             ssp = 1;
         if (type == USB_DT_DEVICE_QUALIFIER)
             hs = !hs;
     }
     list_for_each_entry(c, &cdev->configs, list) {
         /* ignore configs that won't work at this speed */
         if (ssp) {
             if (!c->superspeed_plus)
                 continue;
         } else if (ss) {
             if (!c->superspeed)
                 continue;
         } else if (hs) {
             if (!c->highspeed)
                 continue;
         } else {
             if (!c->fullspeed)
                 continue;
         }
         count++;
     }
     return count;
 }
 
 /**
  * bos_desc() - prepares the BOS descriptor.
  * @cdev: pointer to usb_composite device to generate the bos
  *  descriptor for
  *
  * This function generates the BOS (Binary Device Object)
  * descriptor and its device capabilities descriptors. The BOS
  * descriptor should be supported by a SuperSpeed device.
  */
 static int bos_desc(struct usb_composite_dev *cdev)
 {
     struct usb_ext_cap_descriptor   *usb_ext;
     struct usb_dcd_config_params    dcd_config_params;
     struct usb_bos_descriptor   *bos = cdev->req->buf;
     unsigned int            besl = 0;
 
     bos->bLength = USB_DT_BOS_SIZE;
     bos->bDescriptorType = USB_DT_BOS;
 
     bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE);
     bos->bNumDeviceCaps = 0;
 
     /* Get Controller configuration */
     if (cdev->gadget->ops->get_config_params) {
         cdev->gadget->ops->get_config_params(cdev->gadget,
                              &dcd_config_params);
     } else {
         dcd_config_params.besl_baseline =
             USB_DEFAULT_BESL_UNSPECIFIED;
         dcd_config_params.besl_deep =
             USB_DEFAULT_BESL_UNSPECIFIED;
         dcd_config_params.bU1devExitLat =
             USB_DEFAULT_U1_DEV_EXIT_LAT;
         dcd_config_params.bU2DevExitLat =
             cpu_to_le16(USB_DEFAULT_U2_DEV_EXIT_LAT);
     }
 
     if (dcd_config_params.besl_baseline != USB_DEFAULT_BESL_UNSPECIFIED)
         besl = USB_BESL_BASELINE_VALID |
             USB_SET_BESL_BASELINE(dcd_config_params.besl_baseline);
 
     if (dcd_config_params.besl_deep != USB_DEFAULT_BESL_UNSPECIFIED)
         besl |= USB_BESL_DEEP_VALID |
             USB_SET_BESL_DEEP(dcd_config_params.besl_deep);
 
     /*
      * A SuperSpeed device shall include the USB2.0 extension descriptor
      * and shall support LPM when operating in USB2.0 HS mode.
      */
     usb_ext = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
     bos->bNumDeviceCaps++;
     le16_add_cpu(&bos->wTotalLength, USB_DT_USB_EXT_CAP_SIZE);
     usb_ext->bLength = USB_DT_USB_EXT_CAP_SIZE;
     usb_ext->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
     usb_ext->bDevCapabilityType = USB_CAP_TYPE_EXT;
     usb_ext->bmAttributes = cpu_to_le32(USB_LPM_SUPPORT |
                         USB_BESL_SUPPORT | besl);
 
     /*
      * The Superspeed USB Capability descriptor shall be implemented by all
      * SuperSpeed devices.
      */
     if (gadget_is_superspeed(cdev->gadget)) {
         struct usb_ss_cap_descriptor *ss_cap;
 
         ss_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
         bos->bNumDeviceCaps++;
         le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SS_CAP_SIZE);
         ss_cap->bLength = USB_DT_USB_SS_CAP_SIZE;
         ss_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
         ss_cap->bDevCapabilityType = USB_SS_CAP_TYPE;
         ss_cap->bmAttributes = 0; /* LTM is not supported yet */
         ss_cap->wSpeedSupported = cpu_to_le16(USB_LOW_SPEED_OPERATION |
                               USB_FULL_SPEED_OPERATION |
                               USB_HIGH_SPEED_OPERATION |
                               USB_5GBPS_OPERATION);
         ss_cap->bFunctionalitySupport = USB_LOW_SPEED_OPERATION;
         ss_cap->bU1devExitLat = dcd_config_params.bU1devExitLat;
         ss_cap->bU2DevExitLat = dcd_config_params.bU2DevExitLat;
     }
 
     /* The SuperSpeedPlus USB Device Capability descriptor */
     if (gadget_is_superspeed_plus(cdev->gadget)) {
         struct usb_ssp_cap_descriptor *ssp_cap;
         u8 ssac = 1;
         u8 ssic;
         int i;
 
         if (cdev->gadget->max_ssp_rate == USB_SSP_GEN_2x2)
             ssac = 3;
 
         /*
          * Paired RX and TX sublink speed attributes share
          * the same SSID.
          */
         ssic = (ssac + 1) / 2 - 1;
 
         ssp_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
         bos->bNumDeviceCaps++;
 
         le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SSP_CAP_SIZE(ssac));
         ssp_cap->bLength = USB_DT_USB_SSP_CAP_SIZE(ssac);
         ssp_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
         ssp_cap->bDevCapabilityType = USB_SSP_CAP_TYPE;
         ssp_cap->bReserved = 0;
         ssp_cap->wReserved = 0;
 
         ssp_cap->bmAttributes =
             cpu_to_le32(FIELD_PREP(USB_SSP_SUBLINK_SPEED_ATTRIBS, ssac) |
                     FIELD_PREP(USB_SSP_SUBLINK_SPEED_IDS, ssic));
 
         ssp_cap->wFunctionalitySupport =
             cpu_to_le16(FIELD_PREP(USB_SSP_MIN_SUBLINK_SPEED_ATTRIBUTE_ID, 0) |
                     FIELD_PREP(USB_SSP_MIN_RX_LANE_COUNT, 1) |
                     FIELD_PREP(USB_SSP_MIN_TX_LANE_COUNT, 1));
 
         /*
          * Use 1 SSID if the gadget supports up to gen2x1 or not
          * specified:
          * - SSID 0 for symmetric RX/TX sublink speed of 10 Gbps.
          *
          * Use 1 SSID if the gadget supports up to gen1x2:
          * - SSID 0 for symmetric RX/TX sublink speed of 5 Gbps.
          *
          * Use 2 SSIDs if the gadget supports up to gen2x2:
          * - SSID 0 for symmetric RX/TX sublink speed of 5 Gbps.
          * - SSID 1 for symmetric RX/TX sublink speed of 10 Gbps.
          */
         for (i = 0; i < ssac + 1; i++) {
             u8 ssid;
             u8 mantissa;
             u8 type;
 
             ssid = i >> 1;
 
             if (cdev->gadget->max_ssp_rate == USB_SSP_GEN_2x1 ||
                 cdev->gadget->max_ssp_rate == USB_SSP_GEN_UNKNOWN)
                 mantissa = 10;
             else
                 mantissa = 5 << ssid;
 
             if (i % 2)
                 type = USB_SSP_SUBLINK_SPEED_ST_SYM_TX;
             else
                 type = USB_SSP_SUBLINK_SPEED_ST_SYM_RX;
 
             ssp_cap->bmSublinkSpeedAttr[i] =
                 cpu_to_le32(FIELD_PREP(USB_SSP_SUBLINK_SPEED_SSID, ssid) |
                         FIELD_PREP(USB_SSP_SUBLINK_SPEED_LSE,
                                USB_SSP_SUBLINK_SPEED_LSE_GBPS) |
                         FIELD_PREP(USB_SSP_SUBLINK_SPEED_ST, type) |
                         FIELD_PREP(USB_SSP_SUBLINK_SPEED_LP,
                                USB_SSP_SUBLINK_SPEED_LP_SSP) |
                         FIELD_PREP(USB_SSP_SUBLINK_SPEED_LSM, mantissa));
         }
     }
 
     return le16_to_cpu(bos->wTotalLength);
 }
 
 static void device_qual(struct usb_composite_dev *cdev)
 {
     struct usb_qualifier_descriptor *qual = cdev->req->buf;
 
     qual->bLength = sizeof(*qual);
     qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
     /* POLICY: same bcdUSB and device type info at both speeds */
     qual->bcdUSB = cdev->desc.bcdUSB;
     qual->bDeviceClass = cdev->desc.bDeviceClass;
     qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
     qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
     /* ASSUME same EP0 fifo size at both speeds */
     qual->bMaxPacketSize0 = cdev->gadget->ep0->maxpacket;
     qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
     qual->bRESERVED = 0;
 }
 
 /*-------------------------------------------------------------------------*/
 
 static void reset_config(struct usb_composite_dev *cdev)
 {
     struct usb_function     *f;
 
     DBG(cdev, "reset config\n");
 
     list_for_each_entry(f, &cdev->config->functions, list) {
         if (f->disable)
             f->disable(f);
 
         bitmap_zero(f->endpoints, 32);
     }
     cdev->config = NULL;
     cdev->delayed_status = 0;
 }
 
 static int set_config(struct usb_composite_dev *cdev,
         const struct usb_ctrlrequest *ctrl, unsigned number)
 {
     struct usb_gadget   *gadget = cdev->gadget;
     struct usb_configuration *c = NULL, *iter;
     int         result = -EINVAL;
     unsigned        power = gadget_is_otg(gadget) ? 8 : 100;
     int         tmp;
 
     if (number) {
         list_for_each_entry(iter, &cdev->configs, list) {
             if (iter->bConfigurationValue != number)
                 continue;
             /*
              * We disable the FDs of the previous
              * configuration only if the new configuration
              * is a valid one
              */
             if (cdev->config)
                 reset_config(cdev);
             c = iter;
             result = 0;
             break;
         }
         if (result < 0)
             goto done;
     } else { /* Zero configuration value - need to reset the config */
         if (cdev->config)
             reset_config(cdev);
         result = 0;
     }
 
     DBG(cdev, "%s config #%d: %s\n",
         usb_speed_string(gadget->speed),
         number, c ? c->label : "unconfigured");
 
     if (!c)
         goto done;
 
     usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
     cdev->config = c;
 
     /* Initialize all interfaces by setting them to altsetting zero. */
     for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
         struct usb_function *f = c->interface[tmp];
         struct usb_descriptor_header **descriptors;
 
         if (!f)
             break;
 
         /*
          * Record which endpoints are used by the function. This is used
          * to dispatch control requests targeted at that endpoint to the
          * function's setup callback instead of the current
          * configuration's setup callback.
          */
         descriptors = function_descriptors(f, gadget->speed);
 
         for (; *descriptors; ++descriptors) {
             struct usb_endpoint_descriptor *ep;
             int addr;
 
             if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
                 continue;
 
             ep = (struct usb_endpoint_descriptor *)*descriptors;
             addr = ((ep->bEndpointAddress & 0x80) >> 3)
                  |  (ep->bEndpointAddress & 0x0f);
             set_bit(addr, f->endpoints);
         }
 
         result = f->set_alt(f, tmp, 0);
         if (result < 0) {
             DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
                     tmp, f->name, f, result);
 
             reset_config(cdev);
             goto done;
         }
 
         if (result == USB_GADGET_DELAYED_STATUS) {
             DBG(cdev,
              "%s: interface %d (%s) requested delayed status\n",
                     __func__, tmp, f->name);
             cdev->delayed_status++;
             DBG(cdev, "delayed_status count %d\n",
                     cdev->delayed_status);
         }
     }
 
     /* when we return, be sure our power usage is valid */
     if (c->MaxPower || (c->bmAttributes & USB_CONFIG_ATT_SELFPOWER))
         power = c->MaxPower;
     else
         power = CONFIG_USB_GADGET_VBUS_DRAW;
 
     if (gadget->speed < USB_SPEED_SUPER)
         power = min(power, 500U);
     else
         power = min(power, 900U);
 done:
     if (power <= USB_SELF_POWER_VBUS_MAX_DRAW)
         usb_gadget_set_selfpowered(gadget);
     else
         usb_gadget_clear_selfpowered(gadget);
 
     usb_gadget_vbus_draw(gadget, power);
     if (result >= 0 && cdev->delayed_status)
         result = USB_GADGET_DELAYED_STATUS;
     return result;
 }
 
 int usb_add_config_only(struct usb_composite_dev *cdev,
         struct usb_configuration *config)
 {
     struct usb_configuration *c;
 
     if (!config->bConfigurationValue)
         return -EINVAL;
 
     /* Prevent duplicate configuration identifiers */
     list_for_each_entry(c, &cdev->configs, list) {
         if (c->bConfigurationValue == config->bConfigurationValue)
             return -EBUSY;
     }
 
     config->cdev = cdev;
     list_add_tail(&config->list, &cdev->configs);
 
     INIT_LIST_HEAD(&config->functions);
     config->next_interface_id = 0;
     memset(config->interface, 0, sizeof(config->interface));
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(usb_add_config_only);
 
 /**
  * usb_add_config() - add a configuration to a device.
  * @cdev: wraps the USB gadget
  * @config: the configuration, with bConfigurationValue assigned
  * @bind: the configuration's bind function
  * Context: single threaded during gadget setup
  *
  * One of the main tasks of a composite @bind() routine is to
  * add each of the configurations it supports, using this routine.
  *
  * This function returns the value of the configuration's @bind(), which
  * is zero for success else a negative errno value.  Binding configurations
  * assigns global resources including string IDs, and per-configuration
  * resources such as interface IDs and endpoints.
  */
 int usb_add_config(struct usb_composite_dev *cdev,
         struct usb_configuration *config,
         int (*bind)(struct usb_configuration *))
 {
     int             status = -EINVAL;
 
     if (!bind)
         goto done;
 
     DBG(cdev, "adding config #%u '%s'/%p\n",
             config->bConfigurationValue,
             config->label, config);
 
     status = usb_add_config_only(cdev, config);
     if (status)
         goto done;
 
     status = bind(config);
     if (status < 0) {
         while (!list_empty(&config->functions)) {
             struct usb_function     *f;
 
             f = list_first_entry(&config->functions,
                     struct usb_function, list);
             list_del(&f->list);
             if (f->unbind) {
                 DBG(cdev, "unbind function '%s'/%p\n",
                     f->name, f);
                 f->unbind(config, f);
                 /* may free memory for "f" */
             }
         }
         list_del(&config->list);
         config->cdev = NULL;
     } else {
         unsigned    i;
 
         DBG(cdev, "cfg %d/%p speeds:%s%s%s%s\n",
             config->bConfigurationValue, config,
             config->superspeed_plus ? " superplus" : "",
             config->superspeed ? " super" : "",
             config->highspeed ? " high" : "",
             config->fullspeed
                 ? (gadget_is_dualspeed(cdev->gadget)
                     ? " full"
                     : " full/low")
                 : "");
 
         for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
             struct usb_function *f = config->interface[i];
 
             if (!f)
                 continue;
             DBG(cdev, "  interface %d = %s/%p\n",
                 i, f->name, f);
         }
     }
 
     /* set_alt(), or next bind(), sets up ep->claimed as needed */
     usb_ep_autoconfig_reset(cdev->gadget);
 
 done:
     if (status)
         DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
                 config->bConfigurationValue, status);
     return status;
 }
 EXPORT_SYMBOL_GPL(usb_add_config);
 
 static void remove_config(struct usb_composite_dev *cdev,
                   struct usb_configuration *config)
 {
     while (!list_empty(&config->functions)) {
         struct usb_function     *f;
 
         f = list_first_entry(&config->functions,
                 struct usb_function, list);
 
         usb_remove_function(config, f);
     }
     list_del(&config->list);
     if (config->unbind) {
         DBG(cdev, "unbind config '%s'/%p\n", config->label, config);
         config->unbind(config);
             /* may free memory for "c" */
     }
 }
 
 /**
  * usb_remove_config() - remove a configuration from a device.
  * @cdev: wraps the USB gadget
  * @config: the configuration
  *
  * Drivers must call usb_gadget_disconnect before calling this function
  * to disconnect the device from the host and make sure the host will not
  * try to enumerate the device while we are changing the config list.
  */
 void usb_remove_config(struct usb_composite_dev *cdev,
               struct usb_configuration *config)
 {
     unsigned long flags;
 
     spin_lock_irqsave(&cdev->lock, flags);
 
     if (cdev->config == config)
         reset_config(cdev);
 
     spin_unlock_irqrestore(&cdev->lock, flags);
 
     remove_config(cdev, config);
 }
 
 /*-------------------------------------------------------------------------*/
 
 /* We support strings in multiple languages ... string descriptor zero
  * says which languages are supported.  The typical case will be that
  * only one language (probably English) is used, with i18n handled on
  * the host side.
  */
 
 static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
 {
     const struct usb_gadget_strings *s;
     __le16              language;
     __le16              *tmp;
 
     while (*sp) {
         s = *sp;
         language = cpu_to_le16(s->language);
         for (tmp = buf; *tmp && tmp < &buf[USB_MAX_STRING_LEN]; tmp++) {
             if (*tmp == language)
                 goto repeat;
         }
         *tmp++ = language;
 repeat:
         sp++;
     }
 }
 
 static int lookup_string(
     struct usb_gadget_strings   **sp,
     void                *buf,
     u16             language,
     int             id
 )
 {
     struct usb_gadget_strings   *s;
     int             value;
 
     while (*sp) {
         s = *sp++;
         if (s->language != language)
             continue;
         value = usb_gadget_get_string(s, id, buf);
         if (value > 0)
             return value;
     }
     return -EINVAL;
 }
 
 static int get_string(struct usb_composite_dev *cdev,
         void *buf, u16 language, int id)
 {
     struct usb_composite_driver *composite = cdev->driver;
     struct usb_gadget_string_container *uc;
     struct usb_configuration    *c;
     struct usb_function     *f;
     int             len;
 
     /* Yes, not only is USB's i18n support probably more than most
      * folk will ever care about ... also, it's all supported here.
      * (Except for UTF8 support for Unicode's "Astral Planes".)
      */
 
     /* 0 == report all available language codes */
     if (id == 0) {
         struct usb_string_descriptor    *s = buf;
         struct usb_gadget_strings   **sp;
 
         memset(s, 0, 256);
         s->bDescriptorType = USB_DT_STRING;
 
         sp = composite->strings;
         if (sp)
             collect_langs(sp, s->wData);
 
         list_for_each_entry(c, &cdev->configs, list) {
             sp = c->strings;
             if (sp)
                 collect_langs(sp, s->wData);
 
             list_for_each_entry(f, &c->functions, list) {
                 sp = f->strings;
                 if (sp)
                     collect_langs(sp, s->wData);
             }
         }
         list_for_each_entry(uc, &cdev->gstrings, list) {
             struct usb_gadget_strings **sp;
 
             sp = get_containers_gs(uc);
             collect_langs(sp, s->wData);
         }
 
         for (len = 0; len <= USB_MAX_STRING_LEN && s->wData[len]; len++)
             continue;
         if (!len)
             return -EINVAL;
 
         s->bLength = 2 * (len + 1);
         return s->bLength;
     }
 
     if (cdev->use_os_string && language == 0 && id == OS_STRING_IDX) {
         struct usb_os_string *b = buf;
         b->bLength = sizeof(*b);
         b->bDescriptorType = USB_DT_STRING;
         compiletime_assert(
             sizeof(b->qwSignature) == sizeof(cdev->qw_sign),
             "qwSignature size must be equal to qw_sign");
         memcpy(&b->qwSignature, cdev->qw_sign, sizeof(b->qwSignature));
         b->bMS_VendorCode = cdev->b_vendor_code;
         b->bPad = 0;
         return sizeof(*b);
     }
 
     list_for_each_entry(uc, &cdev->gstrings, list) {
         struct usb_gadget_strings **sp;
 
         sp = get_containers_gs(uc);
         len = lookup_string(sp, buf, language, id);
         if (len > 0)
             return len;
     }
 
     /* String IDs are device-scoped, so we look up each string
      * table we're told about.  These lookups are infrequent;
      * simpler-is-better here.
      */
     if (composite->strings) {
         len = lookup_string(composite->strings, buf, language, id);
         if (len > 0)
             return len;
     }
     list_for_each_entry(c, &cdev->configs, list) {
         if (c->strings) {
             len = lookup_string(c->strings, buf, language, id);
             if (len > 0)
                 return len;
         }
         list_for_each_entry(f, &c->functions, list) {
             if (!f->strings)
                 continue;
             len = lookup_string(f->strings, buf, language, id);
             if (len > 0)
                 return len;
         }
     }
     return -EINVAL;
 }
 
 /**
  * usb_string_id() - allocate an unused string ID
  * @cdev: the device whose string descriptor IDs are being allocated
  * Context: single threaded during gadget setup
  *
  * @usb_string_id() is called from bind() callbacks to allocate
  * string IDs.  Drivers for functions, configurations, or gadgets will
  * then store that ID in the appropriate descriptors and string table.
  *
  * All string identifier should be allocated using this,
  * @usb_string_ids_tab() or @usb_string_ids_n() routine, to ensure
  * that for example different functions don't wrongly assign different
  * meanings to the same identifier.
  */
 int usb_string_id(struct usb_composite_dev *cdev)
 {
     if (cdev->next_string_id < 254) {
         /* string id 0 is reserved by USB spec for list of
          * supported languages */
         /* 255 reserved as well? -- mina86 */
         cdev->next_string_id++;
         return cdev->next_string_id;
     }
     return -ENODEV;
 }
 EXPORT_SYMBOL_GPL(usb_string_id);
 
 /**
  * usb_string_ids_tab() - allocate unused string IDs in batch
  * @cdev: the device whose string descriptor IDs are being allocated
  * @str: an array of usb_string objects to assign numbers to
  * Context: single threaded during gadget setup
  *
  * @usb_string_ids() is called from bind() callbacks to allocate
  * string IDs.  Drivers for functions, configurations, or gadgets will
  * then copy IDs from the string table to the appropriate descriptors
  * and string table for other languages.
  *
  * All string identifier should be allocated using this,
  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
  * example different functions don't wrongly assign different meanings
  * to the same identifier.
  */
 int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str)
 {
     int next = cdev->next_string_id;
 
     for (; str->s; ++str) {
         if (unlikely(next >= 254))
             return -ENODEV;
         str->id = ++next;
     }
 
     cdev->next_string_id = next;
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(usb_string_ids_tab);
 
 static struct usb_gadget_string_container *copy_gadget_strings(
         struct usb_gadget_strings **sp, unsigned n_gstrings,
         unsigned n_strings)
 {
     struct usb_gadget_string_container *uc;
     struct usb_gadget_strings **gs_array;
     struct usb_gadget_strings *gs;
     struct usb_string *s;
     unsigned mem;
     unsigned n_gs;
     unsigned n_s;
     void *stash;
 
     mem = sizeof(*uc);
     mem += sizeof(void *) * (n_gstrings + 1);
     mem += sizeof(struct usb_gadget_strings) * n_gstrings;
     mem += sizeof(struct usb_string) * (n_strings + 1) * (n_gstrings);
     uc = kmalloc(mem, GFP_KERNEL);
     if (!uc)
         return ERR_PTR(-ENOMEM);
     gs_array = get_containers_gs(uc);
     stash = uc->stash;
     stash += sizeof(void *) * (n_gstrings + 1);
     for (n_gs = 0; n_gs < n_gstrings; n_gs++) {
         struct usb_string *org_s;
 
         gs_array[n_gs] = stash;
         gs = gs_array[n_gs];
         stash += sizeof(struct usb_gadget_strings);
         gs->language = sp[n_gs]->language;
         gs->strings = stash;
         org_s = sp[n_gs]->strings;
 
         for (n_s = 0; n_s < n_strings; n_s++) {
             s = stash;
             stash += sizeof(struct usb_string);
             if (org_s->s)
                 s->s = org_s->s;
             else
                 s->s = "";
             org_s++;
         }
         s = stash;
         s->s = NULL;
         stash += sizeof(struct usb_string);
 
     }
     gs_array[n_gs] = NULL;
     return uc;
 }
 
 /**
  * usb_gstrings_attach() - attach gadget strings to a cdev and assign ids
  * @cdev: the device whose string descriptor IDs are being allocated
  * and attached.
  * @sp: an array of usb_gadget_strings to attach.
  * @n_strings: number of entries in each usb_strings array (sp[]->strings)
  *
  * This function will create a deep copy of usb_gadget_strings and usb_string
  * and attach it to the cdev. The actual string (usb_string.s) will not be
  * copied but only a referenced will be made. The struct usb_gadget_strings
  * array may contain multiple languages and should be NULL terminated.
  * The ->language pointer of each struct usb_gadget_strings has to contain the
  * same amount of entries.
  * For instance: sp[0] is en-US, sp[1] is es-ES. It is expected that the first
  * usb_string entry of es-ES contains the translation of the first usb_string
  * entry of en-US. Therefore both entries become the same id assign.
  */
 struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,
         struct usb_gadget_strings **sp, unsigned n_strings)
 {
     struct usb_gadget_string_container *uc;
     struct usb_gadget_strings **n_gs;
     unsigned n_gstrings = 0;
     unsigned i;
     int ret;
 
     for (i = 0; sp[i]; i++)
         n_gstrings++;
 
     if (!n_gstrings)
         return ERR_PTR(-EINVAL);
 
     uc = copy_gadget_strings(sp, n_gstrings, n_strings);
     if (IS_ERR(uc))
         return ERR_CAST(uc);
 
     n_gs = get_containers_gs(uc);
     ret = usb_string_ids_tab(cdev, n_gs[0]->strings);
     if (ret)
         goto err;
 
     for (i = 1; i < n_gstrings; i++) {
         struct usb_string *m_s;
         struct usb_string *s;
         unsigned n;
 
         m_s = n_gs[0]->strings;
         s = n_gs[i]->strings;
         for (n = 0; n < n_strings; n++) {
             s->id = m_s->id;
             s++;
             m_s++;
         }
     }
     list_add_tail(&uc->list, &cdev->gstrings);
     return n_gs[0]->strings;
 err:
     kfree(uc);
     return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(usb_gstrings_attach);
 
 /**
  * usb_string_ids_n() - allocate unused string IDs in batch
  * @c: the device whose string descriptor IDs are being allocated
  * @n: number of string IDs to allocate
  * Context: single threaded during gadget setup
  *
  * Returns the first requested ID.  This ID and next @n-1 IDs are now
  * valid IDs.  At least provided that @n is non-zero because if it
  * is, returns last requested ID which is now very useful information.
  *
  * @usb_string_ids_n() is called from bind() callbacks to allocate
  * string IDs.  Drivers for functions, configurations, or gadgets will
  * then store that ID in the appropriate descriptors and string table.
  *
  * All string identifier should be allocated using this,
  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
  * example different functions don't wrongly assign different meanings
  * to the same identifier.
  */
 int usb_string_ids_n(struct usb_composite_dev *c, unsigned n)
 {
     unsigned next = c->next_string_id;
     if (unlikely(n > 254 || (unsigned)next + n > 254))
         return -ENODEV;
     c->next_string_id += n;
     return next + 1;
 }
 EXPORT_SYMBOL_GPL(usb_string_ids_n);
 
 /*-------------------------------------------------------------------------*/
 
 static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
 {
     struct usb_composite_dev *cdev;
 
     if (req->status || req->actual != req->length)
         DBG((struct usb_composite_dev *) ep->driver_data,
                 "setup complete --> %d, %d/%d\n",
                 req->status, req->actual, req->length);
 
     /*
      * REVIST The same ep0 requests are shared with function drivers
      * so they don't have to maintain the same ->complete() stubs.
      *
      * Because of that, we need to check for the validity of ->context
      * here, even though we know we've set it to something useful.
      */
     if (!req->context)
         return;
 
     cdev = req->context;
 
     if (cdev->req == req)
         cdev->setup_pending = false;
     else if (cdev->os_desc_req == req)
         cdev->os_desc_pending = false;
     else
         WARN(1, "unknown request %p\n", req);
 }
 
 static int composite_ep0_queue(struct usb_composite_dev *cdev,
         struct usb_request *req, gfp_t gfp_flags)
 {
     int ret;
 
     ret = usb_ep_queue(cdev->gadget->ep0, req, gfp_flags);
     if (ret == 0) {
         if (cdev->req == req)
             cdev->setup_pending = true;
         else if (cdev->os_desc_req == req)
             cdev->os_desc_pending = true;
         else
             WARN(1, "unknown request %p\n", req);
     }
 
     return ret;
 }
 
 static int count_ext_compat(struct usb_configuration *c)
 {
     int i, res;
 
     res = 0;
     for (i = 0; i < c->next_interface_id; ++i) {
         struct usb_function *f;
         int j;
 
         f = c->interface[i];
         for (j = 0; j < f->os_desc_n; ++j) {
             struct usb_os_desc *d;
 
             if (i != f->os_desc_table[j].if_id)
                 continue;
             d = f->os_desc_table[j].os_desc;
             if (d && d->ext_compat_id)
                 ++res;
         }
     }
     BUG_ON(res > 255);
     return res;
 }
 
 static int fill_ext_compat(struct usb_configuration *c, u8 *buf)
 {
     int i, count;
 
     count = 16;
     buf += 16;
     for (i = 0; i < c->next_interface_id; ++i) {
         struct usb_function *f;
         int j;
 
         f = c->interface[i];
         for (j = 0; j < f->os_desc_n; ++j) {
             struct usb_os_desc *d;
 
             if (i != f->os_desc_table[j].if_id)
                 continue;
             d = f->os_desc_table[j].os_desc;
             if (d && d->ext_compat_id) {
                 *buf++ = i;
                 *buf++ = 0x01;
                 memcpy(buf, d->ext_compat_id, 16);
                 buf += 22;
             } else {
                 ++buf;
                 *buf = 0x01;
                 buf += 23;
             }
             count += 24;
             if (count + 24 >= USB_COMP_EP0_OS_DESC_BUFSIZ)
                 return count;
         }
     }
 
     return count;
 }
 
 static int count_ext_prop(struct usb_configuration *c, int interface)
 {
     struct usb_function *f;
     int j;
 
     f = c->interface[interface];
     for (j = 0; j < f->os_desc_n; ++j) {
         struct usb_os_desc *d;
 
         if (interface != f->os_desc_table[j].if_id)
             continue;
         d = f->os_desc_table[j].os_desc;
         if (d && d->ext_compat_id)
             return d->ext_prop_count;
     }
     return 0;
 }
 
 static int len_ext_prop(struct usb_configuration *c, int interface)
 {
     struct usb_function *f;
     struct usb_os_desc *d;
     int j, res;
 
     res = 10; /* header length */
     f = c->interface[interface];
     for (j = 0; j < f->os_desc_n; ++j) {
         if (interface != f->os_desc_table[j].if_id)
             continue;
         d = f->os_desc_table[j].os_desc;
         if (d)
             return min(res + d->ext_prop_len, 4096);
     }
     return res;
 }
 
 static int fill_ext_prop(struct usb_configuration *c, int interface, u8 *buf)
 {
     struct usb_function *f;
     struct usb_os_desc *d;
     struct usb_os_desc_ext_prop *ext_prop;
     int j, count, n, ret;
 
     f = c->interface[interface];
     count = 10; /* header length */
     buf += 10;
     for (j = 0; j < f->os_desc_n; ++j) {
         if (interface != f->os_desc_table[j].if_id)
             continue;
         d = f->os_desc_table[j].os_desc;
         if (d)
             list_for_each_entry(ext_prop, &d->ext_prop, entry) {
                 n = ext_prop->data_len +
                     ext_prop->name_len + 14;
                 if (count + n >= USB_COMP_EP0_OS_DESC_BUFSIZ)
                     return count;
                 usb_ext_prop_put_size(buf, n);
                 usb_ext_prop_put_type(buf, ext_prop->type);
                 ret = usb_ext_prop_put_name(buf, ext_prop->name,
                                 ext_prop->name_len);
                 if (ret < 0)
                     return ret;
                 switch (ext_prop->type) {
                 case USB_EXT_PROP_UNICODE:
                 case USB_EXT_PROP_UNICODE_ENV:
                 case USB_EXT_PROP_UNICODE_LINK:
                     usb_ext_prop_put_unicode(buf, ret,
                              ext_prop->data,
                              ext_prop->data_len);
                     break;
                 case USB_EXT_PROP_BINARY:
                     usb_ext_prop_put_binary(buf, ret,
                             ext_prop->data,
                             ext_prop->data_len);
                     break;
                 case USB_EXT_PROP_LE32:
                     /* not implemented */
                 case USB_EXT_PROP_BE32:
                     /* not implemented */
                 default:
                     return -EINVAL;
                 }
                 buf += n;
                 count += n;
             }
     }
 
     return count;
 }
 
 /*
  * The setup() callback implements all the ep0 functionality that's
  * not handled lower down, in hardware or the hardware driver(like
  * device and endpoint feature flags, and their status).  It's all
  * housekeeping for the gadget function we're implementing.  Most of
  * the work is in config and function specific setup.
  */
 int
 composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 {
     struct usb_composite_dev    *cdev = get_gadget_data(gadget);
     struct usb_request      *req = cdev->req;
     int             value = -EOPNOTSUPP;
     int             status = 0;
     u16             w_index = le16_to_cpu(ctrl->wIndex);
     u8              intf = w_index & 0xFF;
     u16             w_value = le16_to_cpu(ctrl->wValue);
     u16             w_length = le16_to_cpu(ctrl->wLength);
     struct usb_function     *f = NULL;
     struct usb_function     *iter;
     u8              endp;
 
     if (w_length > USB_COMP_EP0_BUFSIZ) {
         if (ctrl->bRequestType & USB_DIR_IN) {
             /* Cast away the const, we are going to overwrite on purpose. */
             __le16 *temp = (__le16 *)&ctrl->wLength;
 
             *temp = cpu_to_le16(USB_COMP_EP0_BUFSIZ);
             w_length = USB_COMP_EP0_BUFSIZ;
         } else {
             goto done;
         }
     }
 
     /* partial re-init of the response message; the function or the
      * gadget might need to intercept e.g. a control-OUT completion
      * when we delegate to it.
      */
     req->zero = 0;
     req->context = cdev;
     req->complete = composite_setup_complete;
     req->length = 0;
     gadget->ep0->driver_data = cdev;
 
     /*
      * Don't let non-standard requests match any of the cases below
      * by accident.
      */
     if ((ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_STANDARD)
         goto unknown;
 
     switch (ctrl->bRequest) {
 
     /* we handle all standard USB descriptors */
     case USB_REQ_GET_DESCRIPTOR:
         if (ctrl->bRequestType != USB_DIR_IN)
             goto unknown;
         switch (w_value >> 8) {
 
         case USB_DT_DEVICE:
             cdev->desc.bNumConfigurations =
                 count_configs(cdev, USB_DT_DEVICE);
             cdev->desc.bMaxPacketSize0 =
                 cdev->gadget->ep0->maxpacket;
             if (gadget_is_superspeed(gadget)) {
                 if (gadget->speed >= USB_SPEED_SUPER) {
                     cdev->desc.bcdUSB = cpu_to_le16(0x0320);
                     cdev->desc.bMaxPacketSize0 = 9;
                 } else {
                     cdev->desc.bcdUSB = cpu_to_le16(0x0210);
                 }
             } else {
                 if (gadget->lpm_capable)
                     cdev->desc.bcdUSB = cpu_to_le16(0x0201);
                 else
                     cdev->desc.bcdUSB = cpu_to_le16(0x0200);
             }
 
             value = min(w_length, (u16) sizeof cdev->desc);
             memcpy(req->buf, &cdev->desc, value);
             break;
         case USB_DT_DEVICE_QUALIFIER:
             if (!gadget_is_dualspeed(gadget) ||
                 gadget->speed >= USB_SPEED_SUPER)
                 break;
             device_qual(cdev);
             value = min_t(int, w_length,
                 sizeof(struct usb_qualifier_descriptor));
             break;
         case USB_DT_OTHER_SPEED_CONFIG:
             if (!gadget_is_dualspeed(gadget) ||
                 gadget->speed >= USB_SPEED_SUPER)
                 break;
             fallthrough;
         case USB_DT_CONFIG:
             value = config_desc(cdev, w_value);
             if (value >= 0)
                 value = min(w_length, (u16) value);
             break;
         case USB_DT_STRING:
             value = get_string(cdev, req->buf,
                     w_index, w_value & 0xff);
             if (value >= 0)
                 value = min(w_length, (u16) value);
             break;
         case USB_DT_BOS:
             if (gadget_is_superspeed(gadget) ||
                 gadget->lpm_capable) {
                 value = bos_desc(cdev);
                 value = min(w_length, (u16) value);
             }
             break;
         case USB_DT_OTG:
             if (gadget_is_otg(gadget)) {
                 struct usb_configuration *config;
                 int otg_desc_len = 0;
 
                 if (cdev->config)
                     config = cdev->config;
                 else
                     config = list_first_entry(
                             &cdev->configs,
                         struct usb_configuration, list);
                 if (!config)
                     goto done;
 
                 if (gadget->otg_caps &&
                     (gadget->otg_caps->otg_rev >= 0x0200))
                     otg_desc_len += sizeof(
                         struct usb_otg20_descriptor);
                 else
                     otg_desc_len += sizeof(
                         struct usb_otg_descriptor);
 
                 value = min_t(int, w_length, otg_desc_len);
                 memcpy(req->buf, config->descriptors[0], value);
             }
             break;
         }
         break;
 
     /* any number of configs can work */
     case USB_REQ_SET_CONFIGURATION:
         if (ctrl->bRequestType != 0)
             goto unknown;
         if (gadget_is_otg(gadget)) {
             if (gadget->a_hnp_support)
                 DBG(cdev, "HNP available\n");
             else if (gadget->a_alt_hnp_support)
                 DBG(cdev, "HNP on another port\n");
             else
                 VDBG(cdev, "HNP inactive\n");
         }
         spin_lock(&cdev->lock);
         value = set_config(cdev, ctrl, w_value);
         spin_unlock(&cdev->lock);
         break;
     case USB_REQ_GET_CONFIGURATION:
         if (ctrl->bRequestType != USB_DIR_IN)
             goto unknown;
         if (cdev->config)
             *(u8 *)req->buf = cdev->config->bConfigurationValue;
         else
             *(u8 *)req->buf = 0;
         value = min(w_length, (u16) 1);
         break;
 
     /* function drivers must handle get/set altsetting */
     case USB_REQ_SET_INTERFACE:
         if (ctrl->bRequestType != USB_RECIP_INTERFACE)
             goto unknown;
         if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
             break;
         f = cdev->config->interface[intf];
         if (!f)
             break;
 
         /*
          * If there's no get_alt() method, we know only altsetting zero
          * works. There is no need to check if set_alt() is not NULL
          * as we check this in usb_add_function().
          */
         if (w_value && !f->get_alt)
             break;
 
         spin_lock(&cdev->lock);
         value = f->set_alt(f, w_index, w_value);
         if (value == USB_GADGET_DELAYED_STATUS) {
             DBG(cdev,
              "%s: interface %d (%s) requested delayed status\n",
                     __func__, intf, f->name);
             cdev->delayed_status++;
             DBG(cdev, "delayed_status count %d\n",
                     cdev->delayed_status);
         }
         spin_unlock(&cdev->lock);
         break;
     case USB_REQ_GET_INTERFACE:
         if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
             goto unknown;
         if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
             break;
         f = cdev->config->interface[intf];
         if (!f)
             break;
         /* lots of interfaces only need altsetting zero... */
         value = f->get_alt ? f->get_alt(f, w_index) : 0;
         if (value < 0)
             break;
         *((u8 *)req->buf) = value;
         value = min(w_length, (u16) 1);
         break;
     case USB_REQ_GET_STATUS:
         if (gadget_is_otg(gadget) && gadget->hnp_polling_support &&
                         (w_index == OTG_STS_SELECTOR)) {
             if (ctrl->bRequestType != (USB_DIR_IN |
                             USB_RECIP_DEVICE))
                 goto unknown;
             *((u8 *)req->buf) = gadget->host_request_flag;
             value = 1;
             break;
         }
 
         /*
          * USB 3.0 additions:
          * Function driver should handle get_status request. If such cb
          * wasn't supplied we respond with default value = 0
          * Note: function driver should supply such cb only for the
          * first interface of the function
          */
         if (!gadget_is_superspeed(gadget))
             goto unknown;
         if (ctrl->bRequestType != (USB_DIR_IN | USB_RECIP_INTERFACE))
             goto unknown;
         value = 2;  /* This is the length of the get_status reply */
         put_unaligned_le16(0, req->buf);
         if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
             break;
         f = cdev->config->interface[intf];
         if (!f)
             break;
         status = f->get_status ? f->get_status(f) : 0;
         if (status < 0)
             break;
         put_unaligned_le16(status & 0x0000ffff, req->buf);
         break;
     /*
      * Function drivers should handle SetFeature/ClearFeature
      * (FUNCTION_SUSPEND) request. function_suspend cb should be supplied
      * only for the first interface of the function
      */
     case USB_REQ_CLEAR_FEATURE:
     case USB_REQ_SET_FEATURE:
         if (!gadget_is_superspeed(gadget))
             goto unknown;
         if (ctrl->bRequestType != (USB_DIR_OUT | USB_RECIP_INTERFACE))
             goto unknown;
         switch (w_value) {
         case USB_INTRF_FUNC_SUSPEND:
             if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
                 break;
             f = cdev->config->interface[intf];
             if (!f)
                 break;
             value = 0;
             if (f->func_suspend)
                 value = f->func_suspend(f, w_index >> 8);
             if (value < 0) {
                 ERROR(cdev,
                       "func_suspend() returned error %d\n",
                       value);
                 value = 0;
             }
             break;
         }
         break;
     default:
 unknown:
         /*
          * OS descriptors handling
          */
         if (cdev->use_os_string && cdev->os_desc_config &&
             (ctrl->bRequestType & USB_TYPE_VENDOR) &&
             ctrl->bRequest == cdev->b_vendor_code) {
             struct usb_configuration    *os_desc_cfg;
             u8              *buf;
             int             interface;
             int             count = 0;
 
             req = cdev->os_desc_req;
             req->context = cdev;
             req->complete = composite_setup_complete;
             buf = req->buf;
             os_desc_cfg = cdev->os_desc_config;
             w_length = min_t(u16, w_length, USB_COMP_EP0_OS_DESC_BUFSIZ);
             memset(buf, 0, w_length);
             buf[5] = 0x01;
             switch (ctrl->bRequestType & USB_RECIP_MASK) {
             case USB_RECIP_DEVICE:
                 if (w_index != 0x4 || (w_value >> 8))
                     break;
                 buf[6] = w_index;
                 /* Number of ext compat interfaces */
                 count = count_ext_compat(os_desc_cfg);
                 buf[8] = count;
                 count *= 24; /* 24 B/ext compat desc */
                 count += 16; /* header */
                 put_unaligned_le32(count, buf);
                 value = w_length;
                 if (w_length > 0x10) {
                     value = fill_ext_compat(os_desc_cfg, buf);
                     value = min_t(u16, w_length, value);
                 }
                 break;
             case USB_RECIP_INTERFACE:
                 if (w_index != 0x5 || (w_value >> 8))
                     break;
                 interface = w_value & 0xFF;
                 if (interface >= MAX_CONFIG_INTERFACES ||
                     !os_desc_cfg->interface[interface])
                     break;
                 buf[6] = w_index;
                 count = count_ext_prop(os_desc_cfg,
                     interface);
                 put_unaligned_le16(count, buf + 8);
                 count = len_ext_prop(os_desc_cfg,
                     interface);
                 put_unaligned_le32(count, buf);
                 value = w_length;
                 if (w_length > 0x0A) {
                     value = fill_ext_prop(os_desc_cfg,
                                   interface, buf);
                     if (value >= 0)
                         value = min_t(u16, w_length, value);
                 }
                 break;
             }
 
             goto check_value;
         }
 
         VDBG(cdev,
             "non-core control req%02x.%02x v%04x i%04x l%d\n",
             ctrl->bRequestType, ctrl->bRequest,
             w_value, w_index, w_length);
 
         /* functions always handle their interfaces and endpoints...
          * punt other recipients (other, WUSB, ...) to the current
          * configuration code.
          */
         if (cdev->config) {
             list_for_each_entry(f, &cdev->config->functions, list)
                 if (f->req_match &&
                     f->req_match(f, ctrl, false))
                     goto try_fun_setup;
         } else {
             struct usb_configuration *c;
             list_for_each_entry(c, &cdev->configs, list)
                 list_for_each_entry(f, &c->functions, list)
                     if (f->req_match &&
                         f->req_match(f, ctrl, true))
                         goto try_fun_setup;
         }
         f = NULL;
 
         switch (ctrl->bRequestType & USB_RECIP_MASK) {
         case USB_RECIP_INTERFACE:
             if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
                 break;
             f = cdev->config->interface[intf];
             break;
 
         case USB_RECIP_ENDPOINT:
             if (!cdev->config)
                 break;
             endp = ((w_index & 0x80) >> 3) | (w_index & 0x0f);
             list_for_each_entry(iter, &cdev->config->functions, list) {
                 if (test_bit(endp, iter->endpoints)) {
                     f = iter;
                     break;
                 }
             }
             break;
         }
 try_fun_setup:
         if (f && f->setup)
             value = f->setup(f, ctrl);
         else {
             struct usb_configuration    *c;
 
             c = cdev->config;
             if (!c)
                 goto done;
 
             /* try current config's setup */
             if (c->setup) {
                 value = c->setup(c, ctrl);
                 goto done;
             }
 
             /* try the only function in the current config */
             if (!list_is_singular(&c->functions))
                 goto done;
             f = list_first_entry(&c->functions, struct usb_function,
                          list);
             if (f->setup)
                 value = f->setup(f, ctrl);
         }
 
         goto done;
     }
 
 check_value:
     /* respond with data transfer before status phase? */
     if (value >= 0 && value != USB_GADGET_DELAYED_STATUS) {
         req->length = value;
         req->context = cdev;
         req->zero = value < w_length;
         value = composite_ep0_queue(cdev, req, GFP_ATOMIC);
         if (value < 0) {
             DBG(cdev, "ep_queue --> %d\n", value);
             req->status = 0;
             composite_setup_complete(gadget->ep0, req);
         }
     } else if (value == USB_GADGET_DELAYED_STATUS && w_length != 0) {
         WARN(cdev,
             "%s: Delayed status not supported for w_length != 0",
             __func__);
     }
 
 done:
     /* device either stalls (value < 0) or reports success */
     return value;
 }
 
 static void __composite_disconnect(struct usb_gadget *gadget)
 {
     struct usb_composite_dev    *cdev = get_gadget_data(gadget);
     unsigned long           flags;
 
     /* REVISIT:  should we have config and device level
      * disconnect callbacks?
      */
     spin_lock_irqsave(&cdev->lock, flags);
     cdev->suspended = 0;
     if (cdev->config)
         reset_config(cdev);
     if (cdev->driver->disconnect)
         cdev->driver->disconnect(cdev);
     spin_unlock_irqrestore(&cdev->lock, flags);
 }
 
 void composite_disconnect(struct usb_gadget *gadget)
 {
     usb_gadget_vbus_draw(gadget, 0);
     __composite_disconnect(gadget);
 }
 
 void composite_reset(struct usb_gadget *gadget)
 {
     /*
      * Section 1.4.13 Standard Downstream Port of the USB battery charging
      * specification v1.2 states that a device connected on a SDP shall only
      * draw at max 100mA while in a connected, but unconfigured state.
      */
     usb_gadget_vbus_draw(gadget, 100);
     __composite_disconnect(gadget);
 }
 
 /*-------------------------------------------------------------------------*/
 
 static ssize_t suspended_show(struct device *dev, struct device_attribute *attr,
                   char *buf)
 {
     struct usb_gadget *gadget = dev_to_usb_gadget(dev);
     struct usb_composite_dev *cdev = get_gadget_data(gadget);
 
     return sprintf(buf, "%d\n", cdev->suspended);
 }
 static DEVICE_ATTR_RO(suspended);
 
 static void __composite_unbind(struct usb_gadget *gadget, bool unbind_driver)
 {
     struct usb_composite_dev    *cdev = get_gadget_data(gadget);
     struct usb_gadget_strings   *gstr = cdev->driver->strings[0];
     struct usb_string       *dev_str = gstr->strings;
 
     /* composite_disconnect() must already have been called
      * by the underlying peripheral controller driver!
      * so there's no i/o concurrency that could affect the
      * state protected by cdev->lock.
      */
     WARN_ON(cdev->config);
 
     while (!list_empty(&cdev->configs)) {
         struct usb_configuration    *c;
         c = list_first_entry(&cdev->configs,
                 struct usb_configuration, list);
         remove_config(cdev, c);
     }
     if (cdev->driver->unbind && unbind_driver)
         cdev->driver->unbind(cdev);
 
     composite_dev_cleanup(cdev);
 
     if (dev_str[USB_GADGET_MANUFACTURER_IDX].s == cdev->def_manufacturer)
         dev_str[USB_GADGET_MANUFACTURER_IDX].s = "";
 
     kfree(cdev->def_manufacturer);
     kfree(cdev);
     set_gadget_data(gadget, NULL);
 }
 
 static void composite_unbind(struct usb_gadget *gadget)
 {
     __composite_unbind(gadget, true);
 }
 
 static void update_unchanged_dev_desc(struct usb_device_descriptor *new,
         const struct usb_device_descriptor *old)
 {
     __le16 idVendor;
     __le16 idProduct;
     __le16 bcdDevice;
     u8 iSerialNumber;
     u8 iManufacturer;
     u8 iProduct;
 
     /*
      * these variables may have been set in
      * usb_composite_overwrite_options()
      */
     idVendor = new->idVendor;
     idProduct = new->idProduct;
     bcdDevice = new->bcdDevice;
     iSerialNumber = new->iSerialNumber;
     iManufacturer = new->iManufacturer;
     iProduct = new->iProduct;
 
     *new = *old;
     if (idVendor)
         new->idVendor = idVendor;
     if (idProduct)
         new->idProduct = idProduct;
     if (bcdDevice)
         new->bcdDevice = bcdDevice;
     else
         new->bcdDevice = cpu_to_le16(get_default_bcdDevice());
     if (iSerialNumber)
         new->iSerialNumber = iSerialNumber;
     if (iManufacturer)
         new->iManufacturer = iManufacturer;
     if (iProduct)
         new->iProduct = iProduct;
 }
 
 int composite_dev_prepare(struct usb_composite_driver *composite,
         struct usb_composite_dev *cdev)
 {
     struct usb_gadget *gadget = cdev->gadget;
     int ret = -ENOMEM;
 
     /* preallocate control response and buffer */
     cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
     if (!cdev->req)
         return -ENOMEM;
 
     cdev->req->buf = kzalloc(USB_COMP_EP0_BUFSIZ, GFP_KERNEL);
     if (!cdev->req->buf)
         goto fail;
 
     ret = device_create_file(&gadget->dev, &dev_attr_suspended);
     if (ret)
         goto fail_dev;
 
     cdev->req->complete = composite_setup_complete;
     cdev->req->context = cdev;
     gadget->ep0->driver_data = cdev;
 
     cdev->driver = composite;
 
     /*
      * As per USB compliance update, a device that is actively drawing
      * more than 100mA from USB must report itself as bus-powered in
      * the GetStatus(DEVICE) call.
      */
     if (CONFIG_USB_GADGET_VBUS_DRAW <= USB_SELF_POWER_VBUS_MAX_DRAW)
         usb_gadget_set_selfpowered(gadget);
 
     /* interface and string IDs start at zero via kzalloc.
      * we force endpoints to start unassigned; few controller
      * drivers will zero ep->driver_data.
      */
     usb_ep_autoconfig_reset(gadget);
     return 0;
 fail_dev:
     kfree(cdev->req->buf);
 fail:
     usb_ep_free_request(gadget->ep0, cdev->req);
     cdev->req = NULL;
     return ret;
 }
 
 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
                   struct usb_ep *ep0)
 {
     int ret = 0;
 
     cdev->os_desc_req = usb_ep_alloc_request(ep0, GFP_KERNEL);
     if (!cdev->os_desc_req) {
         ret = -ENOMEM;
         goto end;
     }
 
     cdev->os_desc_req->buf = kmalloc(USB_COMP_EP0_OS_DESC_BUFSIZ,
                      GFP_KERNEL);
     if (!cdev->os_desc_req->buf) {
         ret = -ENOMEM;
         usb_ep_free_request(ep0, cdev->os_desc_req);
         goto end;
     }
     cdev->os_desc_req->context = cdev;
     cdev->os_desc_req->complete = composite_setup_complete;
 end:
     return ret;
 }
 
 void composite_dev_cleanup(struct usb_composite_dev *cdev)
 {
     struct usb_gadget_string_container *uc, *tmp;
     struct usb_ep              *ep, *tmp_ep;
 
     list_for_each_entry_safe(uc, tmp, &cdev->gstrings, list) {
         list_del(&uc->list);
         kfree(uc);
     }
     if (cdev->os_desc_req) {
         if (cdev->os_desc_pending)
             usb_ep_dequeue(cdev->gadget->ep0, cdev->os_desc_req);
 
         kfree(cdev->os_desc_req->buf);
         cdev->os_desc_req->buf = NULL;
         usb_ep_free_request(cdev->gadget->ep0, cdev->os_desc_req);
         cdev->os_desc_req = NULL;
     }
     if (cdev->req) {
         if (cdev->setup_pending)
             usb_ep_dequeue(cdev->gadget->ep0, cdev->req);
 
         kfree(cdev->req->buf);
         cdev->req->buf = NULL;
         usb_ep_free_request(cdev->gadget->ep0, cdev->req);
         cdev->req = NULL;
     }
     cdev->next_string_id = 0;
     device_remove_file(&cdev->gadget->dev, &dev_attr_suspended);
 
     /*
      * Some UDC backends have a dynamic EP allocation scheme.
      *
      * In that case, the dispose() callback is used to notify the
      * backend that the EPs are no longer in use.
      *
      * Note: The UDC backend can remove the EP from the ep_list as
      *   a result, so we need to use the _safe list iterator.
      */
     list_for_each_entry_safe(ep, tmp_ep,
                  &cdev->gadget->ep_list, ep_list) {
         if (ep->ops->dispose)
             ep->ops->dispose(ep);
     }
 }
 
 static int composite_bind(struct usb_gadget *gadget,
         struct usb_gadget_driver *gdriver)
 {
     struct usb_composite_dev    *cdev;
     struct usb_composite_driver *composite = to_cdriver(gdriver);
     int             status = -ENOMEM;
 
     cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
     if (!cdev)
         return status;
 
     spin_lock_init(&cdev->lock);
     cdev->gadget = gadget;
     set_gadget_data(gadget, cdev);
     INIT_LIST_HEAD(&cdev->configs);
     INIT_LIST_HEAD(&cdev->gstrings);
 
     status = composite_dev_prepare(composite, cdev);
     if (status)
         goto fail;
 
     /* composite gadget needs to assign strings for whole device (like
      * serial number), register function drivers, potentially update
      * power state and consumption, etc
      */
     status = composite->bind(cdev);
     if (status < 0)
         goto fail;
 
     if (cdev->use_os_string) {
         status = composite_os_desc_req_prepare(cdev, gadget->ep0);
         if (status)
             goto fail;
     }
 
     update_unchanged_dev_desc(&cdev->desc, composite->dev);
 
     /* has userspace failed to provide a serial number? */
     if (composite->needs_serial && !cdev->desc.iSerialNumber)
         WARNING(cdev, "userspace failed to provide iSerialNumber\n");
 
     INFO(cdev, "%s ready\n", composite->name);
     return 0;
 
 fail:
     __composite_unbind(gadget, false);
     return status;
 }
 
 /*-------------------------------------------------------------------------*/
 
 void composite_suspend(struct usb_gadget *gadget)
 {
     struct usb_composite_dev    *cdev = get_gadget_data(gadget);
     struct usb_function     *f;
 
     /* REVISIT:  should we have config level
      * suspend/resume callbacks?
      */
     DBG(cdev, "suspend\n");
     if (cdev->config) {
         list_for_each_entry(f, &cdev->config->functions, list) {
             if (f->suspend)
                 f->suspend(f);
         }
     }
     if (cdev->driver->suspend)
         cdev->driver->suspend(cdev);
 
     cdev->suspended = 1;
 
     usb_gadget_set_selfpowered(gadget);
     usb_gadget_vbus_draw(gadget, 2);
 }
 
 void composite_resume(struct usb_gadget *gadget)
 {
     struct usb_composite_dev    *cdev = get_gadget_data(gadget);
     struct usb_function     *f;
     unsigned            maxpower;
 
     /* REVISIT:  should we have config level
      * suspend/resume callbacks?
      */
     DBG(cdev, "resume\n");
     if (cdev->driver->resume)
         cdev->driver->resume(cdev);
     if (cdev->config) {
         list_for_each_entry(f, &cdev->config->functions, list) {
             if (f->resume)
                 f->resume(f);
         }
 
         maxpower = cdev->config->MaxPower ?
             cdev->config->MaxPower : CONFIG_USB_GADGET_VBUS_DRAW;
         if (gadget->speed < USB_SPEED_SUPER)
             maxpower = min(maxpower, 500U);
         else
             maxpower = min(maxpower, 900U);
 
         if (maxpower > USB_SELF_POWER_VBUS_MAX_DRAW)
             usb_gadget_clear_selfpowered(gadget);
 
         usb_gadget_vbus_draw(gadget, maxpower);
     }
 
     cdev->suspended = 0;
 }
 
 /*-------------------------------------------------------------------------*/
 
 static const struct usb_gadget_driver composite_driver_template = {
     .bind       = composite_bind,
     .unbind     = composite_unbind,
 
     .setup      = composite_setup,
     .reset      = composite_reset,
     .disconnect = composite_disconnect,
 
     .suspend    = composite_suspend,
     .resume     = composite_resume,
 
     .driver = {
         .owner      = THIS_MODULE,
     },
 };
 
 /**
  * usb_composite_probe() - register a composite driver
  * @driver: the driver to register
  *
  * Context: single threaded during gadget setup
  *
  * This function is used to register drivers using the composite driver
  * framework.  The return value is zero, or a negative errno value.
  * Those values normally come from the driver's @bind method, which does
  * all the work of setting up the driver to match the hardware.
  *
  * On successful return, the gadget is ready to respond to requests from
  * the host, unless one of its components invokes usb_gadget_disconnect()
  * while it was binding.  That would usually be done in order to wait for
  * some userspace participation.
  */
 int usb_composite_probe(struct usb_composite_driver *driver)
 {
     struct usb_gadget_driver *gadget_driver;
 
     if (!driver || !driver->dev || !driver->bind)
         return -EINVAL;
 
     if (!driver->name)
         driver->name = "composite";
 
     driver->gadget_driver = composite_driver_template;
     gadget_driver = &driver->gadget_driver;
 
     gadget_driver->function =  (char *) driver->name;
     gadget_driver->driver.name = driver->name;
     gadget_driver->max_speed = driver->max_speed;
 
     return usb_gadget_register_driver(gadget_driver);
 }
 EXPORT_SYMBOL_GPL(usb_composite_probe);
 
 /**
  * usb_composite_unregister() - unregister a composite driver
  * @driver: the driver to unregister
  *
  * This function is used to unregister drivers using the composite
  * driver framework.
  */
 void usb_composite_unregister(struct usb_composite_driver *driver)
 {
     usb_gadget_unregister_driver(&driver->gadget_driver);
 }
 EXPORT_SYMBOL_GPL(usb_composite_unregister);
 
 /**
  * usb_composite_setup_continue() - Continue with the control transfer
  * @cdev: the composite device who's control transfer was kept waiting
  *
  * This function must be called by the USB function driver to continue
  * with the control transfer's data/status stage in case it had requested to
  * delay the data/status stages. A USB function's setup handler (e.g. set_alt())
  * can request the composite framework to delay the setup request's data/status
  * stages by returning USB_GADGET_DELAYED_STATUS.
  */
 void usb_composite_setup_continue(struct usb_composite_dev *cdev)
 {
     int         value;
     struct usb_request  *req = cdev->req;
     unsigned long       flags;
 
     DBG(cdev, "%s\n", __func__);
     spin_lock_irqsave(&cdev->lock, flags);
 
     if (cdev->delayed_status == 0) {
         WARN(cdev, "%s: Unexpected call\n", __func__);
 
     } else if (--cdev->delayed_status == 0) {
         DBG(cdev, "%s: Completing delayed status\n", __func__);
         req->length = 0;
         req->context = cdev;
         value = composite_ep0_queue(cdev, req, GFP_ATOMIC);
         if (value < 0) {
             DBG(cdev, "ep_queue --> %d\n", value);
             req->status = 0;
             composite_setup_complete(cdev->gadget->ep0, req);
         }
     }
 
     spin_unlock_irqrestore(&cdev->lock, flags);
 }
 EXPORT_SYMBOL_GPL(usb_composite_setup_continue);
 
 static char *composite_default_mfr(struct usb_gadget *gadget)
 {
     return kasprintf(GFP_KERNEL, "%s %s with %s", init_utsname()->sysname,
              init_utsname()->release, gadget->name);
 }
 
 void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
         struct usb_composite_overwrite *covr)
 {
     struct usb_device_descriptor    *desc = &cdev->desc;
     struct usb_gadget_strings   *gstr = cdev->driver->strings[0];
     struct usb_string       *dev_str = gstr->strings;
 
     if (covr->idVendor)
         desc->idVendor = cpu_to_le16(covr->idVendor);
 
     if (covr->idProduct)
         desc->idProduct = cpu_to_le16(covr->idProduct);
 
     if (covr->bcdDevice)
         desc->bcdDevice = cpu_to_le16(covr->bcdDevice);
 
     if (covr->serial_number) {
         desc->iSerialNumber = dev_str[USB_GADGET_SERIAL_IDX].id;
         dev_str[USB_GADGET_SERIAL_IDX].s = covr->serial_number;
     }
     if (covr->manufacturer) {
         desc->iManufacturer = dev_str[USB_GADGET_MANUFACTURER_IDX].id;
         dev_str[USB_GADGET_MANUFACTURER_IDX].s = covr->manufacturer;
 
     } else if (!strlen(dev_str[USB_GADGET_MANUFACTURER_IDX].s)) {
         desc->iManufacturer = dev_str[USB_GADGET_MANUFACTURER_IDX].id;
         cdev->def_manufacturer = composite_default_mfr(cdev->gadget);
         dev_str[USB_GADGET_MANUFACTURER_IDX].s = cdev->def_manufacturer;
     }
 
     if (covr->product) {
         desc->iProduct = dev_str[USB_GADGET_PRODUCT_IDX].id;
         dev_str[USB_GADGET_PRODUCT_IDX].s = covr->product;
     }
 }
 EXPORT_SYMBOL_GPL(usb_composite_overwrite_options);
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("David Brownell");

This page was automatically generated by the 2.1.0 LXR engine. The LXR team