8 files changed, 670 insertions, 163 deletions

diff --git a/drivers/usb/gadget/function/Makefile b/drivers/usb/gadget/function/Makefile
index 90701aa5a826..dd68091d92f0 100644
--- a/drivers/usb/gadget/function/Makefile
+++ b/drivers/usb/gadget/function/Makefile
@@ -38,3 +38,7 @@ usb_f_uac2-y			:= f_uac2.o
 obj-$(CONFIG_USB_F_UAC2)	+= usb_f_uac2.o
 usb_f_uvc-y			:= f_uvc.o uvc_queue.o uvc_v4l2.o uvc_video.o
 obj-$(CONFIG_USB_F_UVC)		+= usb_f_uvc.o
+usb_f_midi-y			:= f_midi.o
+obj-$(CONFIG_USB_F_MIDI)	+= usb_f_midi.o
+usb_f_hid-y			:= f_hid.o
+obj-$(CONFIG_USB_F_HID)		+= usb_f_hid.o
diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index ea2b9c374305..6e04e302dc3a 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/hid.h>
+#include <linux/idr.h>
 #include <linux/cdev.h>
 #include <linux/mutex.h>
 #include <linux/poll.h>
@@ -21,9 +22,14 @@
 #include <linux/usb/g_hid.h>
 
 #include "u_f.h"
+#include "u_hid.h"
+
+#define HIDG_MINORS	4
 
 static int major, minors;
 static struct class *hidg_class;
+static DEFINE_IDA(hidg_ida);
+static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */
 
 /*-------------------------------------------------------------------------*/
 /*                            HID gadget struct                            */
@@ -161,6 +167,26 @@ static struct usb_descriptor_header *hidg_fs_descriptors[] = {
 };
 
 /*-------------------------------------------------------------------------*/
+/*                                 Strings                                 */
+
+#define CT_FUNC_HID_IDX	0
+
+static struct usb_string ct_func_string_defs[] = {
+	[CT_FUNC_HID_IDX].s	= "HID Interface",
+	{},			/* end of list */
+};
+
+static struct usb_gadget_strings ct_func_string_table = {
+	.language	= 0x0409,	/* en-US */
+	.strings	= ct_func_string_defs,
+};
+
+static struct usb_gadget_strings *ct_func_strings[] = {
+	&ct_func_string_table,
+	NULL,
+};
+
+/*-------------------------------------------------------------------------*/
 /*                              Char Device                                */
 
 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
@@ -552,13 +578,22 @@ const struct file_operations f_hidg_fops = {
 	.llseek		= noop_llseek,
 };
 
-static int __init hidg_bind(struct usb_configuration *c, struct usb_function *f)
+static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
 {
 	struct usb_ep		*ep;
 	struct f_hidg		*hidg = func_to_hidg(f);
+	struct usb_string	*us;
+	struct device		*device;
 	int			status;
 	dev_t			dev;
 
+	/* maybe allocate device-global string IDs, and patch descriptors */
+	us = usb_gstrings_attach(c->cdev, ct_func_strings,
+				 ARRAY_SIZE(ct_func_string_defs));
+	if (IS_ERR(us))
+		return PTR_ERR(us);
+	hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
+
 	/* allocate instance-specific interface IDs, and patch descriptors */
 	status = usb_interface_id(c, f);
 	if (status < 0)
@@ -623,10 +658,16 @@ static int __init hidg_bind(struct usb_configuration *c, struct usb_function *f)
 	if (status)
 		goto fail_free_descs;
 
-	device_create(hidg_class, NULL, dev, NULL, "%s%d", "hidg", hidg->minor);
+	device = device_create(hidg_class, NULL, dev, NULL,
+			       "%s%d", "hidg", hidg->minor);
+	if (IS_ERR(device)) {
+		status = PTR_ERR(device);
+		goto del;
+	}
 
 	return 0;
-
+del:
+	cdev_del(&hidg->cdev);
 fail_free_descs:
 	usb_free_all_descriptors(f);
 fail:
@@ -640,116 +681,313 @@ fail:
 	return status;
 }
 
-static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
+static inline int hidg_get_minor(void)
 {
-	struct f_hidg *hidg = func_to_hidg(f);
+	int ret;
 
-	device_destroy(hidg_class, MKDEV(major, hidg->minor));
-	cdev_del(&hidg->cdev);
+	ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL);
 
-	/* disable/free request and end point */
-	usb_ep_disable(hidg->in_ep);
-	usb_ep_dequeue(hidg->in_ep, hidg->req);
-	kfree(hidg->req->buf);
-	usb_ep_free_request(hidg->in_ep, hidg->req);
-
-	usb_free_all_descriptors(f);
+	return ret;
+}
 
-	kfree(hidg->report_desc);
-	kfree(hidg);
+static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct f_hid_opts,
+			    func_inst.group);
 }
 
-/*-------------------------------------------------------------------------*/
-/*                                 Strings                                 */
+CONFIGFS_ATTR_STRUCT(f_hid_opts);
+CONFIGFS_ATTR_OPS(f_hid_opts);
 
-#define CT_FUNC_HID_IDX	0
+static void hid_attr_release(struct config_item *item)
+{
+	struct f_hid_opts *opts = to_f_hid_opts(item);
 
-static struct usb_string ct_func_string_defs[] = {
-	[CT_FUNC_HID_IDX].s	= "HID Interface",
-	{},			/* end of list */
-};
+	usb_put_function_instance(&opts->func_inst);
+}
 
-static struct usb_gadget_strings ct_func_string_table = {
-	.language	= 0x0409,	/* en-US */
-	.strings	= ct_func_string_defs,
+static struct configfs_item_operations hidg_item_ops = {
+	.release	= hid_attr_release,
+	.show_attribute	= f_hid_opts_attr_show,
+	.store_attribute = f_hid_opts_attr_store,
 };
 
-static struct usb_gadget_strings *ct_func_strings[] = {
-	&ct_func_string_table,
+#define F_HID_OPT(name, prec, limit)					\
+static ssize_t f_hid_opts_##name##_show(struct f_hid_opts *opts, char *page)\
+{									\
+	int result;							\
+									\
+	mutex_lock(&opts->lock);					\
+	result = sprintf(page, "%d\n", opts->name);			\
+	mutex_unlock(&opts->lock);					\
+									\
+	return result;							\
+}									\
+									\
+static ssize_t f_hid_opts_##name##_store(struct f_hid_opts *opts,	\
+					 const char *page, size_t len)	\
+{									\
+	int ret;							\
+	u##prec num;							\
+									\
+	mutex_lock(&opts->lock);					\
+	if (opts->refcnt) {						\
+		ret = -EBUSY;						\
+		goto end;						\
+	}								\
+									\
+	ret = kstrtou##prec(page, 0, &num);				\
+	if (ret)							\
+		goto end;						\
+									\
+	if (num > limit) {						\
+		ret = -EINVAL;						\
+		goto end;						\
+	}								\
+	opts->name = num;						\
+	ret = len;							\
+									\
+end:									\
+	mutex_unlock(&opts->lock);					\
+	return ret;							\
+}									\
+									\
+static struct f_hid_opts_attribute f_hid_opts_##name =			\
+	__CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR, f_hid_opts_##name##_show,\
+			f_hid_opts_##name##_store)
+
+F_HID_OPT(subclass, 8, 255);
+F_HID_OPT(protocol, 8, 255);
+F_HID_OPT(report_length, 16, 65536);
+
+static ssize_t f_hid_opts_report_desc_show(struct f_hid_opts *opts, char *page)
+{
+	int result;
+
+	mutex_lock(&opts->lock);
+	result = opts->report_desc_length;
+	memcpy(page, opts->report_desc, opts->report_desc_length);
+	mutex_unlock(&opts->lock);
+
+	return result;
+}
+
+static ssize_t f_hid_opts_report_desc_store(struct f_hid_opts *opts,
+					    const char *page, size_t len)
+{
+	int ret = -EBUSY;
+	char *d;
+
+	mutex_lock(&opts->lock);
+
+	if (opts->refcnt)
+		goto end;
+	if (len > PAGE_SIZE) {
+		ret = -ENOSPC;
+		goto end;
+	}
+	d = kmemdup(page, len, GFP_KERNEL);
+	if (!d) {
+		ret = -ENOMEM;
+		goto end;
+	}
+	kfree(opts->report_desc);
+	opts->report_desc = d;
+	opts->report_desc_length = len;
+	opts->report_desc_alloc = true;
+	ret = len;
+end:
+	mutex_unlock(&opts->lock);
+	return ret;
+}
+
+static struct f_hid_opts_attribute f_hid_opts_report_desc =
+	__CONFIGFS_ATTR(report_desc, S_IRUGO | S_IWUSR,
+			f_hid_opts_report_desc_show,
+			f_hid_opts_report_desc_store);
+
+static struct configfs_attribute *hid_attrs[] = {
+	&f_hid_opts_subclass.attr,
+	&f_hid_opts_protocol.attr,
+	&f_hid_opts_report_length.attr,
+	&f_hid_opts_report_desc.attr,
 	NULL,
 };
 
-/*-------------------------------------------------------------------------*/
-/*                             usb_configuration                           */
+static struct config_item_type hid_func_type = {
+	.ct_item_ops	= &hidg_item_ops,
+	.ct_attrs	= hid_attrs,
+	.ct_owner	= THIS_MODULE,
+};
 
-int __init hidg_bind_config(struct usb_configuration *c,
-			    struct hidg_func_descriptor *fdesc, int index)
+static inline void hidg_put_minor(int minor)
 {
-	struct f_hidg *hidg;
-	int status;
+	ida_simple_remove(&hidg_ida, minor);
+}
 
-	if (index >= minors)
-		return -ENOENT;
+static void hidg_free_inst(struct usb_function_instance *f)
+{
+	struct f_hid_opts *opts;
 
-	/* maybe allocate device-global string IDs, and patch descriptors */
-	if (ct_func_string_defs[CT_FUNC_HID_IDX].id == 0) {
-		status = usb_string_id(c->cdev);
-		if (status < 0)
-			return status;
-		ct_func_string_defs[CT_FUNC_HID_IDX].id = status;
-		hidg_interface_desc.iInterface = status;
+	opts = container_of(f, struct f_hid_opts, func_inst);
+
+	mutex_lock(&hidg_ida_lock);
+
+	hidg_put_minor(opts->minor);
+	if (idr_is_empty(&hidg_ida.idr))
+		ghid_cleanup();
+
+	mutex_unlock(&hidg_ida_lock);
+
+	if (opts->report_desc_alloc)
+		kfree(opts->report_desc);
+
+	kfree(opts);
+}
+
+static struct usb_function_instance *hidg_alloc_inst(void)
+{
+	struct f_hid_opts *opts;
+	struct usb_function_instance *ret;
+	int status = 0;
+
+	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+	if (!opts)
+		return ERR_PTR(-ENOMEM);
+	mutex_init(&opts->lock);
+	opts->func_inst.free_func_inst = hidg_free_inst;
+	ret = &opts->func_inst;
+
+	mutex_lock(&hidg_ida_lock);
+
+	if (idr_is_empty(&hidg_ida.idr)) {
+		status = ghid_setup(NULL, HIDG_MINORS);
+		if (status)  {
+			ret = ERR_PTR(status);
+			kfree(opts);
+			goto unlock;
+		}
+	}
+
+	opts->minor = hidg_get_minor();
+	if (opts->minor < 0) {
+		ret = ERR_PTR(opts->minor);
+		kfree(opts);
+		if (idr_is_empty(&hidg_ida.idr))
+			ghid_cleanup();
+		goto unlock;
 	}
+	config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
+
+unlock:
+	mutex_unlock(&hidg_ida_lock);
+	return ret;
+}
+
+static void hidg_free(struct usb_function *f)
+{
+	struct f_hidg *hidg;
+	struct f_hid_opts *opts;
+
+	hidg = func_to_hidg(f);
+	opts = container_of(f->fi, struct f_hid_opts, func_inst);
+	kfree(hidg->report_desc);
+	kfree(hidg);
+	mutex_lock(&opts->lock);
+	--opts->refcnt;
+	mutex_unlock(&opts->lock);
+}
+
+static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+	struct f_hidg *hidg = func_to_hidg(f);
+
+	device_destroy(hidg_class, MKDEV(major, hidg->minor));
+	cdev_del(&hidg->cdev);
+
+	/* disable/free request and end point */
+	usb_ep_disable(hidg->in_ep);
+	usb_ep_dequeue(hidg->in_ep, hidg->req);
+	kfree(hidg->req->buf);
+	usb_ep_free_request(hidg->in_ep, hidg->req);
+
+	usb_free_all_descriptors(f);
+}
+
+static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
+{
+	struct f_hidg *hidg;
+	struct f_hid_opts *opts;
 
 	/* allocate and initialize one new instance */
-	hidg = kzalloc(sizeof *hidg, GFP_KERNEL);
+	hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
 	if (!hidg)
-		return -ENOMEM;
-
-	hidg->minor = index;
-	hidg->bInterfaceSubClass = fdesc->subclass;
-	hidg->bInterfaceProtocol = fdesc->protocol;
-	hidg->report_length = fdesc->report_length;
-	hidg->report_desc_length = fdesc->report_desc_length;
-	hidg->report_desc = kmemdup(fdesc->report_desc,
-				    fdesc->report_desc_length,
-				    GFP_KERNEL);
-	if (!hidg->report_desc) {
-		kfree(hidg);
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
+
+	opts = container_of(fi, struct f_hid_opts, func_inst);
+
+	mutex_lock(&opts->lock);
+	++opts->refcnt;
+
+	hidg->minor = opts->minor;
+	hidg->bInterfaceSubClass = opts->subclass;
+	hidg->bInterfaceProtocol = opts->protocol;
+	hidg->report_length = opts->report_length;
+	hidg->report_desc_length = opts->report_desc_length;
+	if (opts->report_desc) {
+		hidg->report_desc = kmemdup(opts->report_desc,
+					    opts->report_desc_length,
+					    GFP_KERNEL);
+		if (!hidg->report_desc) {
+			kfree(hidg);
+			mutex_unlock(&opts->lock);
+			return ERR_PTR(-ENOMEM);
+		}
 	}
 
+	mutex_unlock(&opts->lock);
+
 	hidg->func.name    = "hid";
-	hidg->func.strings = ct_func_strings;
 	hidg->func.bind    = hidg_bind;
 	hidg->func.unbind  = hidg_unbind;
 	hidg->func.set_alt = hidg_set_alt;
 	hidg->func.disable = hidg_disable;
 	hidg->func.setup   = hidg_setup;
+	hidg->func.free_func = hidg_free;
 
 	/* this could me made configurable at some point */
 	hidg->qlen	   = 4;
 
-	status = usb_add_function(c, &hidg->func);
-	if (status)
-		kfree(hidg);
-
-	return status;
+	return &hidg->func;
 }
 
-int __init ghid_setup(struct usb_gadget *g, int count)
+DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Fabien Chouteau");
+
+int ghid_setup(struct usb_gadget *g, int count)
 {
 	int status;
 	dev_t dev;
 
 	hidg_class = class_create(THIS_MODULE, "hidg");
+	if (IS_ERR(hidg_class)) {
+		status = PTR_ERR(hidg_class);
+		hidg_class = NULL;
+		return status;
+	}
 
 	status = alloc_chrdev_region(&dev, 0, count, "hidg");
-	if (!status) {
-		major = MAJOR(dev);
-		minors = count;
+	if (status) {
+		class_destroy(hidg_class);
+		hidg_class = NULL;
+		return status;
 	}
 
-	return status;
+	major = MAJOR(dev);
+	minors = count;
+
+	return 0;
 }
 
 void ghid_cleanup(void)
diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
index 807b31c0edc3..a90440300735 100644
--- a/drivers/usb/gadget/function/f_midi.c
+++ b/drivers/usb/gadget/function/f_midi.c
@@ -20,6 +20,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/device.h>
 
@@ -33,6 +34,7 @@
 #include <linux/usb/midi.h>
 
 #include "u_f.h"
+#include "u_midi.h"
 
 MODULE_AUTHOR("Ben Williamson");
 MODULE_LICENSE("GPL v2");
@@ -99,7 +101,7 @@ DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(1);
 DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(16);
 
 /* B.3.1  Standard AC Interface Descriptor */
-static struct usb_interface_descriptor ac_interface_desc __initdata = {
+static struct usb_interface_descriptor ac_interface_desc = {
 	.bLength =		USB_DT_INTERFACE_SIZE,
 	.bDescriptorType =	USB_DT_INTERFACE,
 	/* .bInterfaceNumber =	DYNAMIC */
@@ -110,7 +112,7 @@ static struct usb_interface_descriptor ac_interface_desc __initdata = {
 };
 
 /* B.3.2  Class-Specific AC Interface Descriptor */
-static struct uac1_ac_header_descriptor_1 ac_header_desc __initdata = {
+static struct uac1_ac_header_descriptor_1 ac_header_desc = {
 	.bLength =		UAC_DT_AC_HEADER_SIZE(1),
 	.bDescriptorType =	USB_DT_CS_INTERFACE,
 	.bDescriptorSubtype =	USB_MS_HEADER,
@@ -121,7 +123,7 @@ static struct uac1_ac_header_descriptor_1 ac_header_desc __initdata = {
 };
 
 /* B.4.1  Standard MS Interface Descriptor */
-static struct usb_interface_descriptor ms_interface_desc __initdata = {
+static struct usb_interface_descriptor ms_interface_desc = {
 	.bLength =		USB_DT_INTERFACE_SIZE,
 	.bDescriptorType =	USB_DT_INTERFACE,
 	/* .bInterfaceNumber =	DYNAMIC */
@@ -132,7 +134,7 @@ static struct usb_interface_descriptor ms_interface_desc __initdata = {
 };
 
 /* B.4.2  Class-Specific MS Interface Descriptor */
-static struct usb_ms_header_descriptor ms_header_desc __initdata = {
+static struct usb_ms_header_descriptor ms_header_desc = {
 	.bLength =		USB_DT_MS_HEADER_SIZE,
 	.bDescriptorType =	USB_DT_CS_INTERFACE,
 	.bDescriptorSubtype =	USB_MS_HEADER,
@@ -387,29 +389,6 @@ static void f_midi_disable(struct usb_function *f)
 	usb_ep_disable(midi->out_ep);
 }
 
-static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f)
-{
-	struct usb_composite_dev *cdev = f->config->cdev;
-	struct f_midi *midi = func_to_midi(f);
-	struct snd_card *card;
-
-	DBG(cdev, "unbind\n");
-
-	/* just to be sure */
-	f_midi_disable(f);
-
-	card = midi->card;
-	midi->card = NULL;
-	if (card)
-		snd_card_free(card);
-
-	kfree(midi->id);
-	midi->id = NULL;
-
-	usb_free_all_descriptors(f);
-	kfree(midi);
-}
-
 static int f_midi_snd_free(struct snd_device *device)
 {
 	return 0;
@@ -654,6 +633,14 @@ static struct snd_rawmidi_ops gmidi_out_ops = {
 	.trigger = f_midi_out_trigger
 };
 
+static inline void f_midi_unregister_card(struct f_midi *midi)
+{
+	if (midi->card) {
+		snd_card_free(midi->card);
+		midi->card = NULL;
+	}
+}
+
 /* register as a sound "card" */
 static int f_midi_register_card(struct f_midi *midi)
 {
@@ -715,17 +702,13 @@ static int f_midi_register_card(struct f_midi *midi)
 	return 0;
 
 fail:
-	if (midi->card) {
-		snd_card_free(midi->card);
-		midi->card = NULL;
-	}
+	f_midi_unregister_card(midi);
 	return err;
 }
 
 /* MIDI function driver setup/binding */
 
-static int __init
-f_midi_bind(struct usb_configuration *c, struct usb_function *f)
+static int f_midi_bind(struct usb_configuration *c, struct usb_function *f)
 {
 	struct usb_descriptor_header **midi_function;
 	struct usb_midi_in_jack_descriptor jack_in_ext_desc[MAX_PORTS];
@@ -734,15 +717,23 @@ f_midi_bind(struct usb_configuration *c, struct usb_function *f)
 	struct usb_midi_out_jack_descriptor_1 jack_out_emb_desc[MAX_PORTS];
 	struct usb_composite_dev *cdev = c->cdev;
 	struct f_midi *midi = func_to_midi(f);
+	struct usb_string *us;
 	int status, n, jack = 1, i = 0;
 
+	midi->gadget = cdev->gadget;
+	tasklet_init(&midi->tasklet, f_midi_in_tasklet, (unsigned long) midi);
+	status = f_midi_register_card(midi);
+	if (status < 0)
+		goto fail_register;
+
 	/* maybe allocate device-global string ID */
-	if (midi_string_defs[0].id == 0) {
-		status = usb_string_id(c->cdev);
-		if (status < 0)
-			goto fail;
-		midi_string_defs[0].id = status;
+	us = usb_gstrings_attach(c->cdev, midi_strings,
+				 ARRAY_SIZE(midi_string_defs));
+	if (IS_ERR(us)) {
+		status = PTR_ERR(us);
+		goto fail;
 	}
+	ac_interface_desc.iInterface = us[STRING_FUNC_IDX].id;
 
 	/* We have two interfaces, AudioControl and MIDIStreaming */
 	status = usb_interface_id(c, f);
@@ -892,6 +883,8 @@ fail_f_midi:
 	kfree(midi_function);
 	usb_free_descriptors(f->hs_descriptors);
 fail:
+	f_midi_unregister_card(midi);
+fail_register:
 	/* we might as well release our claims on endpoints */
 	if (midi->out_ep)
 		midi->out_ep->driver_data = NULL;
@@ -903,42 +896,235 @@ fail:
 	return status;
 }
 
-/**
- * f_midi_bind_config - add USB MIDI function to a configuration
- * @c: the configuration to supcard the USB audio function
- * @index: the soundcard index to use for the ALSA device creation
- * @id: the soundcard id to use for the ALSA device creation
- * @buflen: the buffer length to use
- * @qlen the number of read requests to pre-allocate
- * Context: single threaded during gadget setup
- *
- * Returns zero on success, else negative errno.
- */
-int __init f_midi_bind_config(struct usb_configuration *c,
-			      int index, char *id,
-			      unsigned int in_ports,
-			      unsigned int out_ports,
-			      unsigned int buflen,
-			      unsigned int qlen)
+static inline struct f_midi_opts *to_f_midi_opts(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct f_midi_opts,
+			    func_inst.group);
+}
+
+CONFIGFS_ATTR_STRUCT(f_midi_opts);
+CONFIGFS_ATTR_OPS(f_midi_opts);
+
+static void midi_attr_release(struct config_item *item)
+{
+	struct f_midi_opts *opts = to_f_midi_opts(item);
+
+	usb_put_function_instance(&opts->func_inst);
+}
+
+static struct configfs_item_operations midi_item_ops = {
+	.release	= midi_attr_release,
+	.show_attribute	= f_midi_opts_attr_show,
+	.store_attribute = f_midi_opts_attr_store,
+};
+
+#define F_MIDI_OPT(name, test_limit, limit)				\
+static ssize_t f_midi_opts_##name##_show(struct f_midi_opts *opts, char *page) \
+{									\
+	int result;							\
+									\
+	mutex_lock(&opts->lock);					\
+	result = sprintf(page, "%d\n", opts->name);			\
+	mutex_unlock(&opts->lock);					\
+									\
+	return result;							\
+}									\
+									\
+static ssize_t f_midi_opts_##name##_store(struct f_midi_opts *opts,	\
+					 const char *page, size_t len)	\
+{									\
+	int ret;							\
+	u32 num;							\
+									\
+	mutex_lock(&opts->lock);					\
+	if (opts->refcnt) {						\
+		ret = -EBUSY;						\
+		goto end;						\
+	}								\
+									\
+	ret = kstrtou32(page, 0, &num);					\
+	if (ret)							\
+		goto end;						\
+									\
+	if (test_limit && num > limit) {				\
+		ret = -EINVAL;						\
+		goto end;						\
+	}								\
+	opts->name = num;						\
+	ret = len;							\
+									\
+end:									\
+	mutex_unlock(&opts->lock);					\
+	return ret;							\
+}									\
+									\
+static struct f_midi_opts_attribute f_midi_opts_##name =		\
+	__CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR, f_midi_opts_##name##_show, \
+			f_midi_opts_##name##_store)
+
+F_MIDI_OPT(index, true, SNDRV_CARDS);
+F_MIDI_OPT(buflen, false, 0);
+F_MIDI_OPT(qlen, false, 0);
+F_MIDI_OPT(in_ports, true, MAX_PORTS);
+F_MIDI_OPT(out_ports, true, MAX_PORTS);
+
+static ssize_t f_midi_opts_id_show(struct f_midi_opts *opts, char *page)
+{
+	int result;
+
+	mutex_lock(&opts->lock);
+	result = strlcpy(page, opts->id, PAGE_SIZE);
+	mutex_unlock(&opts->lock);
+
+	return result;
+}
+
+static ssize_t f_midi_opts_id_store(struct f_midi_opts *opts,
+				    const char *page, size_t len)
+{
+	int ret;
+	char *c;
+
+	mutex_lock(&opts->lock);
+	if (opts->refcnt) {
+		ret = -EBUSY;
+		goto end;
+	}
+
+	c = kstrndup(page, len, GFP_KERNEL);
+	if (!c) {
+		ret = -ENOMEM;
+		goto end;
+	}
+	if (opts->id_allocated)
+		kfree(opts->id);
+	opts->id = c;
+	opts->id_allocated = true;
+	ret = len;
+end:
+	mutex_unlock(&opts->lock);
+	return ret;
+}
+
+static struct f_midi_opts_attribute f_midi_opts_id =
+	__CONFIGFS_ATTR(id, S_IRUGO | S_IWUSR, f_midi_opts_id_show,
+			f_midi_opts_id_store);
+
+static struct configfs_attribute *midi_attrs[] = {
+	&f_midi_opts_index.attr,
+	&f_midi_opts_buflen.attr,
+	&f_midi_opts_qlen.attr,
+	&f_midi_opts_in_ports.attr,
+	&f_midi_opts_out_ports.attr,
+	&f_midi_opts_id.attr,
+	NULL,
+};
+
+static struct config_item_type midi_func_type = {
+	.ct_item_ops	= &midi_item_ops,
+	.ct_attrs	= midi_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+static void f_midi_free_inst(struct usb_function_instance *f)
+{
+	struct f_midi_opts *opts;
+
+	opts = container_of(f, struct f_midi_opts, func_inst);
+
+	if (opts->id_allocated)
+		kfree(opts->id);
+
+	kfree(opts);
+}
+
+static struct usb_function_instance *f_midi_alloc_inst(void)
+{
+	struct f_midi_opts *opts;
+
+	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+	if (!opts)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_init(&opts->lock);
+	opts->func_inst.free_func_inst = f_midi_free_inst;
+	opts->index = SNDRV_DEFAULT_IDX1;
+	opts->id = SNDRV_DEFAULT_STR1;
+	opts->buflen = 256;
+	opts->qlen = 32;
+	opts->in_ports = 1;
+	opts->out_ports = 1;
+
+	config_group_init_type_name(&opts->func_inst.group, "",
+				    &midi_func_type);
+
+	return &opts->func_inst;
+}
+
+static void f_midi_free(struct usb_function *f)
+{
+	struct f_midi *midi;
+	struct f_midi_opts *opts;
+	int i;
+
+	midi = func_to_midi(f);
+	opts = container_of(f->fi, struct f_midi_opts, func_inst);
+	kfree(midi->id);
+	mutex_lock(&opts->lock);
+	for (i = opts->in_ports - 1; i >= 0; --i)
+		kfree(midi->in_port[i]);
+	kfree(midi);
+	--opts->refcnt;
+	mutex_unlock(&opts->lock);
+}
+
+static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+	struct usb_composite_dev *cdev = f->config->cdev;
+	struct f_midi *midi = func_to_midi(f);
+	struct snd_card *card;
+
+	DBG(cdev, "unbind\n");
+
+	/* just to be sure */
+	f_midi_disable(f);
+
+	card = midi->card;
+	midi->card = NULL;
+	if (card)
+		snd_card_free(card);
+
+	usb_free_all_descriptors(f);
+}
+
+static struct usb_function *f_midi_alloc(struct usb_function_instance *fi)
 {
 	struct f_midi *midi;
+	struct f_midi_opts *opts;
 	int status, i;
 
+	opts = container_of(fi, struct f_midi_opts, func_inst);
+
+	mutex_lock(&opts->lock);
 	/* sanity check */
-	if (in_ports > MAX_PORTS || out_ports > MAX_PORTS)
-		return -EINVAL;
+	if (opts->in_ports > MAX_PORTS || opts->out_ports > MAX_PORTS) {
+		mutex_unlock(&opts->lock);
+		return ERR_PTR(-EINVAL);
+	}
 
 	/* allocate and initialize one new instance */
-	midi = kzalloc(sizeof *midi, GFP_KERNEL);
+	midi = kzalloc(sizeof(*midi), GFP_KERNEL);
 	if (!midi) {
-		status = -ENOMEM;
-		goto fail;
+		mutex_unlock(&opts->lock);
+		return ERR_PTR(-ENOMEM);
 	}
 
-	for (i = 0; i < in_ports; i++) {
+	for (i = 0; i < opts->in_ports; i++) {
 		struct gmidi_in_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
+
 		if (!port) {
 			status = -ENOMEM;
+			mutex_unlock(&opts->lock);
 			goto setup_fail;
 		}
 
@@ -948,39 +1134,37 @@ int __init f_midi_bind_config(struct usb_configuration *c,
 		midi->in_port[i] = port;
 	}
 
-	midi->gadget = c->cdev->gadget;
-	tasklet_init(&midi->tasklet, f_midi_in_tasklet, (unsigned long) midi);
-
 	/* set up ALSA midi devices */
-	midi->in_ports = in_ports;
-	midi->out_ports = out_ports;
-	status = f_midi_register_card(midi);
-	if (status < 0)
-		goto setup_fail;
-
-	midi->func.name        = "gmidi function";
-	midi->func.strings     = midi_strings;
-	midi->func.bind        = f_midi_bind;
-	midi->func.unbind      = f_midi_unbind;
-	midi->func.set_alt     = f_midi_set_alt;
-	midi->func.disable     = f_midi_disable;
-
-	midi->id = kstrdup(id, GFP_KERNEL);
-	midi->index = index;
-	midi->buflen = buflen;
-	midi->qlen = qlen;
-
-	status = usb_add_function(c, &midi->func);
-	if (status)
-		goto setup_fail;
-
-	return 0;
-
+	midi->id = kstrdup(opts->id, GFP_KERNEL);
+	if (opts->id && !midi->id) {
+		status = -ENOMEM;
+		mutex_unlock(&opts->lock);
+		goto kstrdup_fail;
+	}
+	midi->in_ports = opts->in_ports;
+	midi->out_ports = opts->out_ports;
+	midi->index = opts->index;
+	midi->buflen = opts->buflen;
+	midi->qlen = opts->qlen;
+	++opts->refcnt;
+	mutex_unlock(&opts->lock);
+
+	midi->func.name		= "gmidi function";
+	midi->func.bind		= f_midi_bind;
+	midi->func.unbind	= f_midi_unbind;
+	midi->func.set_alt	= f_midi_set_alt;
+	midi->func.disable	= f_midi_disable;
+	midi->func.free_func	= f_midi_free;
+
+	return &midi->func;
+
+kstrdup_fail:
+	f_midi_unregister_card(midi);
 setup_fail:
 	for (--i; i >= 0; i--)
 		kfree(midi->in_port[i]);
 	kfree(midi);
-fail:
-	return status;
+	return ERR_PTR(status);
 }
 
+DECLARE_USB_FUNCTION_INIT(midi, f_midi_alloc_inst, f_midi_alloc);
diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c
index 16361b0a8b46..bdcda9f5148e 100644
--- a/drivers/usb/gadget/function/f_ncm.c
+++ b/drivers/usb/gadget/function/f_ncm.c
@@ -1441,6 +1441,9 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
 
 	status = usb_assign_descriptors(f, ncm_fs_function, ncm_hs_function,
 			NULL);
+	if (status)
+		goto fail;
+
 	/*
 	 * NOTE:  all that is done without knowing or caring about
 	 * the network link ... which is unavailable to this code
diff --git a/drivers/usb/gadget/function/f_rndis.c b/drivers/usb/gadget/function/f_rndis.c
index f13fc6a58565..829edf878dac 100644
--- a/drivers/usb/gadget/function/f_rndis.c
+++ b/drivers/usb/gadget/function/f_rndis.c
@@ -375,8 +375,7 @@ static struct sk_buff *rndis_add_header(struct gether *port,
 	struct sk_buff *skb2;
 
 	skb2 = skb_realloc_headroom(skb, sizeof(struct rndis_packet_msg_type));
-	if (skb2)
-		rndis_add_hdr(skb2);
+	rndis_add_hdr(skb2);
 
 	dev_kfree_skb(skb);
 	return skb2;
diff --git a/drivers/usb/gadget/function/u_hid.h b/drivers/usb/gadget/function/u_hid.h
new file mode 100644
index 000000000000..aaa0e368a159
--- /dev/null
+++ b/drivers/usb/gadget/function/u_hid.h
@@ -0,0 +1,42 @@
+/*
+ * u_hid.h
+ *
+ * Utility definitions for the hid function
+ *
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef U_HID_H
+#define U_HID_H
+
+#include <linux/usb/composite.h>
+
+struct f_hid_opts {
+	struct usb_function_instance	func_inst;
+	int				minor;
+	unsigned char			subclass;
+	unsigned char			protocol;
+	unsigned short			report_length;
+	unsigned short			report_desc_length;
+	unsigned char			*report_desc;
+	bool				report_desc_alloc;
+
+	/*
+	 * Protect the data form concurrent access by read/write
+	 * and create symlink/remove symlink.
+	 */
+	 struct mutex			lock;
+	 int				refcnt;
+};
+
+int ghid_setup(struct usb_gadget *g, int count);
+void ghid_cleanup(void);
+
+#endif /* U_HID_H */
diff --git a/drivers/usb/gadget/function/u_midi.h b/drivers/usb/gadget/function/u_midi.h
new file mode 100644
index 000000000000..22510189758e
--- /dev/null
+++ b/drivers/usb/gadget/function/u_midi.h
@@ -0,0 +1,40 @@
+/*
+ * u_midi.h
+ *
+ * Utility definitions for the midi function
+ *
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef U_MIDI_H
+#define U_MIDI_H
+
+#include <linux/usb/composite.h>
+
+struct f_midi_opts {
+	struct usb_function_instance	func_inst;
+	int				index;
+	char				*id;
+	bool				id_allocated;
+	unsigned int			in_ports;
+	unsigned int			out_ports;
+	unsigned int			buflen;
+	unsigned int			qlen;
+
+	/*
+	 * Protect the data form concurrent access by read/write
+	 * and create symlink/remove symlink.
+	 */
+	 struct mutex			lock;
+	 int				refcnt;
+};
+
+#endif /* U_MIDI_H */
+
diff --git a/drivers/usb/gadget/function/u_uac1.c b/drivers/usb/gadget/function/u_uac1.c
index a44a07f30281..53842a1b947f 100644
--- a/drivers/usb/gadget/function/u_uac1.c
+++ b/drivers/usb/gadget/function/u_uac1.c
@@ -213,9 +213,6 @@ static int gaudio_open_snd_dev(struct gaudio *card)
 	fn_cap = opts->fn_cap;
 	fn_cntl = opts->fn_cntl;
 
-	if (!card)
-		return -ENODEV;
-
 	/* Open control device */
 	snd = &card->control;
 	snd->filp = filp_open(fn_cntl, O_RDWR, 0);