1 files changed, 605 insertions, 70 deletions

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 2a6bfe759c2..f8015193205 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -21,6 +21,24 @@
 #include <linux/usb/composite.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"
@@ -28,6 +46,12 @@
  * 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;
+}
+
 /**
  * next_ep_desc() - advance to the next EP descriptor
  * @t: currect pointer within descriptor array
@@ -215,6 +239,18 @@ done:
 }
 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);
+}
+EXPORT_SYMBOL_GPL(usb_remove_function);
+
 /**
  * usb_function_deactivate - prevent function and gadget enumeration
  * @function: the function that isn't yet ready to respond
@@ -320,6 +356,25 @@ int usb_interface_id(struct usb_configuration *config,
 }
 EXPORT_SYMBOL_GPL(usb_interface_id);
 
+static u8 encode_bMaxPower(enum usb_device_speed speed,
+		struct usb_configuration *c)
+{
+	unsigned val;
+
+	if (c->MaxPower)
+		val = c->MaxPower;
+	else
+		val = CONFIG_USB_GADGET_VBUS_DRAW;
+	if (!val)
+		return 0;
+	switch (speed) {
+	case USB_SPEED_SUPER:
+		return DIV_ROUND_UP(val, 8);
+	default:
+		return DIV_ROUND_UP(val, 2);
+	}
+}
+
 static int config_buf(struct usb_configuration *config,
 		enum usb_device_speed speed, void *buf, u8 type)
 {
@@ -339,7 +394,7 @@ static int config_buf(struct usb_configuration *config,
 	c->bConfigurationValue = config->bConfigurationValue;
 	c->iConfiguration = config->iConfiguration;
 	c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
-	c->bMaxPower = config->bMaxPower ? : (CONFIG_USB_GADGET_VBUS_DRAW / 2);
+	c->bMaxPower = encode_bMaxPower(speed, config);
 
 	/* There may be e.g. OTG descriptors */
 	if (config->descriptors) {
@@ -385,6 +440,7 @@ 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;
 
@@ -403,7 +459,20 @@ static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
 
 	/* This is a lookup by config *INDEX* */
 	w_value &= 0xff;
-	list_for_each_entry(c, &cdev->configs, list) {
+
+	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:
@@ -556,6 +625,7 @@ static void reset_config(struct usb_composite_dev *cdev)
 		bitmap_zero(f->endpoints, 32);
 	}
 	cdev->config = NULL;
+	cdev->delayed_status = 0;
 }
 
 static int set_config(struct usb_composite_dev *cdev,
@@ -596,6 +666,7 @@ static int set_config(struct usb_composite_dev *cdev,
 	if (!c)
 		goto done;
 
+	usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
 	cdev->config = c;
 
 	/* Initialize all interfaces by setting them to altsetting zero. */
@@ -656,7 +727,7 @@ static int set_config(struct usb_composite_dev *cdev,
 	}
 
 	/* when we return, be sure our power usage is valid */
-	power = c->bMaxPower ? (2 * c->bMaxPower) : CONFIG_USB_GADGET_VBUS_DRAW;
+	power = c->MaxPower ? c->MaxPower : CONFIG_USB_GADGET_VBUS_DRAW;
 done:
 	usb_gadget_vbus_draw(gadget, power);
 	if (result >= 0 && cdev->delayed_status)
@@ -664,6 +735,31 @@ done:
 	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
@@ -684,30 +780,18 @@ int usb_add_config(struct usb_composite_dev *cdev,
 		int (*bind)(struct usb_configuration *))
 {
 	int				status = -EINVAL;
-	struct usb_configuration	*c;
+
+	if (!bind)
+		goto done;
 
 	DBG(cdev, "adding config #%u '%s'/%p\n",
 			config->bConfigurationValue,
 			config->label, config);
 
-	if (!config->bConfigurationValue || !bind)
+	status = usb_add_config_only(cdev, config);
+	if (status)
 		goto done;
 
-	/* Prevent duplicate configuration identifiers */
-	list_for_each_entry(c, &cdev->configs, list) {
-		if (c->bConfigurationValue == config->bConfigurationValue) {
-			status = -EBUSY;
-			goto done;
-		}
-	}
-
-	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));
-
 	status = bind(config);
 	if (status < 0) {
 		while (!list_empty(&config->functions)) {
@@ -860,6 +944,7 @@ 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;
@@ -892,6 +977,12 @@ static int get_string(struct usb_composite_dev *cdev,
 					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 <= 126 && s->wData[len]; len++)
 			continue;
@@ -902,6 +993,28 @@ static int get_string(struct usb_composite_dev *cdev,
 		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.
@@ -987,6 +1100,119 @@ int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str)
 }
 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 languges 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 containts 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
@@ -1026,6 +1252,156 @@ static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
 				req->status, req->actual, req->length);
 }
 
+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 void fill_ext_compat(struct usb_configuration *c, u8 *buf)
+{
+	int i, count;
+
+	count = 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 >= 4096)
+				return;
+		}
+	}
+}
+
+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;
+	u8 *start = buf;
+
+	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)
+			list_for_each_entry(ext_prop, &d->ext_prop, entry) {
+				/* 4kB minus header length */
+				n = buf - start;
+				if (n >= 4086)
+					return 0;
+
+				count = ext_prop->data_len +
+					ext_prop->name_len + 14;
+				if (count > 4086 - n)
+					return -EINVAL;
+				usb_ext_prop_put_size(buf, count);
+				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 += count;
+			}
+	}
+
+	return 0;
+}
+
 /*
  * The setup() callback implements all the ep0 functionality that's
  * not handled lower down, in hardware or the hardware driver(like
@@ -1033,7 +1409,7 @@ static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
  * housekeeping for the gadget function we're implementing.  Most of
  * the work is in config and function specific setup.
  */
-static int
+int
 composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 {
 	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
@@ -1235,6 +1611,91 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 		break;
 	default:
 unknown:
+		/*
+		 * OS descriptors handling
+		 */
+		if (cdev->use_os_string && cdev->os_desc_config &&
+		    (ctrl->bRequest & USB_TYPE_VENDOR) &&
+		    ctrl->bRequest == cdev->b_vendor_code) {
+			struct usb_request		*req;
+			struct usb_configuration	*os_desc_cfg;
+			u8				*buf;
+			int				interface;
+			int				count = 0;
+
+			req = cdev->os_desc_req;
+			req->complete = composite_setup_complete;
+			buf = req->buf;
+			os_desc_cfg = cdev->os_desc_config;
+			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;
+				if (w_length == 0x10) {
+					/* 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;
+				} else {
+					/* "extended compatibility ID"s */
+					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);
+					buf += 16;
+					fill_ext_compat(os_desc_cfg, buf);
+					value = w_length;
+				}
+				break;
+			case USB_RECIP_INTERFACE:
+				if (w_index != 0x5 || (w_value >> 8))
+					break;
+				interface = w_value & 0xFF;
+				buf[6] = w_index;
+				if (w_length == 0x0A) {
+					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;
+				} else {
+					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);
+					buf += 10;
+					value = fill_ext_prop(os_desc_cfg,
+							      interface, buf);
+					if (value < 0)
+						return value;
+
+					value = w_length;
+				}
+				break;
+			}
+			req->length = value;
+			req->zero = value < w_length;
+			value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
+			if (value < 0) {
+				DBG(cdev, "ep_queue --> %d\n", value);
+				req->status = 0;
+				composite_setup_complete(gadget->ep0, req);
+			}
+			return value;
+		}
+
 		VDBG(cdev,
 			"non-core control req%02x.%02x v%04x i%04x l%d\n",
 			ctrl->bRequestType, ctrl->bRequest,
@@ -1272,8 +1733,22 @@ unknown:
 			struct usb_configuration	*c;
 
 			c = cdev->config;
-			if (c && c->setup)
+			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;
@@ -1300,7 +1775,7 @@ done:
 	return value;
 }
 
-static void composite_disconnect(struct usb_gadget *gadget)
+void composite_disconnect(struct usb_gadget *gadget)
 {
 	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
 	unsigned long			flags;
@@ -1318,20 +1793,17 @@ static void composite_disconnect(struct usb_gadget *gadget)
 
 /*-------------------------------------------------------------------------*/
 
-static ssize_t composite_show_suspended(struct device *dev,
-					struct device_attribute *attr,
-					char *buf)
+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 DEVICE_ATTR(suspended, 0444, composite_show_suspended, NULL);
-
-static void
-composite_unbind(struct usb_gadget *gadget)
+static void __composite_unbind(struct usb_gadget *gadget, bool unbind_driver)
 {
 	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
 
@@ -1348,19 +1820,21 @@ composite_unbind(struct usb_gadget *gadget)
 				struct usb_configuration, list);
 		remove_config(cdev, c);
 	}
-	if (cdev->driver->unbind)
+	if (cdev->driver->unbind && unbind_driver)
 		cdev->driver->unbind(cdev);
 
-	if (cdev->req) {
-		kfree(cdev->req->buf);
-		usb_ep_free_request(gadget->ep0, cdev->req);
-	}
-	device_remove_file(&gadget->dev, &dev_attr_suspended);
+	composite_dev_cleanup(cdev);
+
 	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)
 {
@@ -1399,34 +1873,25 @@ static void update_unchanged_dev_desc(struct usb_device_descriptor *new,
 		new->iProduct = iProduct;
 }
 
-static struct usb_composite_driver *to_cdriver(struct usb_gadget_driver *gdrv)
-{
-	return container_of(gdrv, struct usb_composite_driver, gadget_driver);
-}
-
-static int composite_bind(struct usb_gadget *gadget,
-		struct usb_gadget_driver *gdriver)
+int composite_dev_prepare(struct usb_composite_driver *composite,
+		struct usb_composite_dev *cdev)
 {
-	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);
+	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)
-		goto fail;
+		return -ENOMEM;
+
 	cdev->req->buf = kmalloc(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;
 	gadget->ep0->driver_data = cdev;
 
@@ -1444,7 +1909,79 @@ static int composite_bind(struct usb_gadget *gadget,
 	 * we force endpoints to start unassigned; few controller
 	 * drivers will zero ep->driver_data.
 	 */
-	usb_ep_autoconfig_reset(cdev->gadget);
+	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 = PTR_ERR(cdev->os_desc_req);
+		goto end;
+	}
+
+	/* OS feature descriptor length <= 4kB */
+	cdev->os_desc_req->buf = kmalloc(4096, GFP_KERNEL);
+	if (!cdev->os_desc_req->buf) {
+		ret = PTR_ERR(cdev->os_desc_req->buf);
+		kfree(cdev->os_desc_req);
+		goto end;
+	}
+	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;
+
+	list_for_each_entry_safe(uc, tmp, &cdev->gstrings, list) {
+		list_del(&uc->list);
+		kfree(uc);
+	}
+	if (cdev->os_desc_req) {
+		kfree(cdev->os_desc_req->buf);
+		usb_ep_free_request(cdev->gadget->ep0, cdev->os_desc_req);
+	}
+	if (cdev->req) {
+		kfree(cdev->req->buf);
+		usb_ep_free_request(cdev->gadget->ep0, cdev->req);
+	}
+	cdev->next_string_id = 0;
+	device_remove_file(&cdev->gadget->dev, &dev_attr_suspended);
+}
+
+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
@@ -1454,22 +1991,23 @@ static int composite_bind(struct usb_gadget *gadget,
 	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");
 
-	/* finish up */
-	status = device_create_file(&gadget->dev, &dev_attr_suspended);
-	if (status)
-		goto fail;
-
 	INFO(cdev, "%s ready\n", composite->name);
 	return 0;
 
 fail:
-	composite_unbind(gadget);
+	__composite_unbind(gadget, false);
 	return status;
 }
 
@@ -1504,7 +2042,7 @@ composite_resume(struct usb_gadget *gadget)
 {
 	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
 	struct usb_function		*f;
-	u8				maxpower;
+	u16				maxpower;
 
 	/* REVISIT:  should we have config level
 	 * suspend/resume callbacks?
@@ -1518,10 +2056,10 @@ composite_resume(struct usb_gadget *gadget)
 				f->resume(f);
 		}
 
-		maxpower = cdev->config->bMaxPower;
+		maxpower = cdev->config->MaxPower;
 
 		usb_gadget_vbus_draw(gadget, maxpower ?
-			(2 * maxpower) : CONFIG_USB_GADGET_VBUS_DRAW);
+			maxpower : CONFIG_USB_GADGET_VBUS_DRAW);
 	}
 
 	cdev->suspended = 0;
@@ -1547,10 +2085,7 @@ static const struct usb_gadget_driver composite_driver_template = {
 /**
  * usb_composite_probe() - register a composite driver
  * @driver: the driver to register
- * @bind: the callback used to allocate resources that are shared across the
- *	whole device, such as string IDs, and add its configurations using
- *	@usb_add_config().  This may fail by returning a negative errno
- *	value; it should return zero on successful initialization.
+ *
  * Context: single threaded during gadget setup
  *
  * This function is used to register drivers using the composite driver