Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1357 insertions, 0 deletions

diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
new file mode 100644
index 000000000..f1ca9250c
--- /dev/null
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -0,0 +1,1357 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * f_hid.c -- USB HID function driver
+ *
+ * Copyright (C) 2010 Fabien Chouteau <fabien.chouteau@barco.com>
+ */
+
+#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>
+#include <linux/uaccess.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#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                            */
+
+struct f_hidg_req_list {
+	struct usb_request	*req;
+	unsigned int		pos;
+	struct list_head 	list;
+};
+
+struct f_hidg {
+	/* configuration */
+	unsigned char			bInterfaceSubClass;
+	unsigned char			bInterfaceProtocol;
+	unsigned char			protocol;
+	unsigned char			idle;
+	unsigned short			report_desc_length;
+	char				*report_desc;
+	unsigned short			report_length;
+	/*
+	 * use_out_ep - if true, the OUT Endpoint (interrupt out method)
+	 *              will be used to receive reports from the host
+	 *              using functions with the "intout" suffix.
+	 *              Otherwise, the OUT Endpoint will not be configured
+	 *              and the SETUP/SET_REPORT method ("ssreport" suffix)
+	 *              will be used to receive reports.
+	 */
+	bool				use_out_ep;
+
+	/* recv report */
+	spinlock_t			read_spinlock;
+	wait_queue_head_t		read_queue;
+	/* recv report - interrupt out only (use_out_ep == 1) */
+	struct list_head		completed_out_req;
+	unsigned int			qlen;
+	/* recv report - setup set_report only (use_out_ep == 0) */
+	char				*set_report_buf;
+	unsigned int			set_report_length;
+
+	/* send report */
+	spinlock_t			write_spinlock;
+	bool				write_pending;
+	wait_queue_head_t		write_queue;
+	struct usb_request		*req;
+
+	struct device			dev;
+	struct cdev			cdev;
+	struct usb_function		func;
+
+	struct usb_ep			*in_ep;
+	struct usb_ep			*out_ep;
+};
+
+static inline struct f_hidg *func_to_hidg(struct usb_function *f)
+{
+	return container_of(f, struct f_hidg, func);
+}
+
+static void hidg_release(struct device *dev)
+{
+	struct f_hidg *hidg = container_of(dev, struct f_hidg, dev);
+
+	kfree(hidg->report_desc);
+	kfree(hidg->set_report_buf);
+	kfree(hidg);
+}
+
+/*-------------------------------------------------------------------------*/
+/*                           Static descriptors                            */
+
+static struct usb_interface_descriptor hidg_interface_desc = {
+	.bLength		= sizeof hidg_interface_desc,
+	.bDescriptorType	= USB_DT_INTERFACE,
+	/* .bInterfaceNumber	= DYNAMIC */
+	.bAlternateSetting	= 0,
+	/* .bNumEndpoints	= DYNAMIC (depends on use_out_ep) */
+	.bInterfaceClass	= USB_CLASS_HID,
+	/* .bInterfaceSubClass	= DYNAMIC */
+	/* .bInterfaceProtocol	= DYNAMIC */
+	/* .iInterface		= DYNAMIC */
+};
+
+static struct hid_descriptor hidg_desc = {
+	.bLength			= sizeof hidg_desc,
+	.bDescriptorType		= HID_DT_HID,
+	.bcdHID				= cpu_to_le16(0x0101),
+	.bCountryCode			= 0x00,
+	.bNumDescriptors		= 0x1,
+	/*.desc[0].bDescriptorType	= DYNAMIC */
+	/*.desc[0].wDescriptorLenght	= DYNAMIC */
+};
+
+/* Super-Speed Support */
+
+static struct usb_endpoint_descriptor hidg_ss_in_ep_desc = {
+	.bLength		= USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType	= USB_DT_ENDPOINT,
+	.bEndpointAddress	= USB_DIR_IN,
+	.bmAttributes		= USB_ENDPOINT_XFER_INT,
+	/*.wMaxPacketSize	= DYNAMIC */
+	.bInterval		= 4, /* FIXME: Add this field in the
+				      * HID gadget configuration?
+				      * (struct hidg_func_descriptor)
+				      */
+};
+
+static struct usb_ss_ep_comp_descriptor hidg_ss_in_comp_desc = {
+	.bLength                = sizeof(hidg_ss_in_comp_desc),
+	.bDescriptorType        = USB_DT_SS_ENDPOINT_COMP,
+
+	/* .bMaxBurst           = 0, */
+	/* .bmAttributes        = 0, */
+	/* .wBytesPerInterval   = DYNAMIC */
+};
+
+static struct usb_endpoint_descriptor hidg_ss_out_ep_desc = {
+	.bLength		= USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType	= USB_DT_ENDPOINT,
+	.bEndpointAddress	= USB_DIR_OUT,
+	.bmAttributes		= USB_ENDPOINT_XFER_INT,
+	/*.wMaxPacketSize	= DYNAMIC */
+	.bInterval		= 4, /* FIXME: Add this field in the
+				      * HID gadget configuration?
+				      * (struct hidg_func_descriptor)
+				      */
+};
+
+static struct usb_ss_ep_comp_descriptor hidg_ss_out_comp_desc = {
+	.bLength                = sizeof(hidg_ss_out_comp_desc),
+	.bDescriptorType        = USB_DT_SS_ENDPOINT_COMP,
+
+	/* .bMaxBurst           = 0, */
+	/* .bmAttributes        = 0, */
+	/* .wBytesPerInterval   = DYNAMIC */
+};
+
+static struct usb_descriptor_header *hidg_ss_descriptors_intout[] = {
+	(struct usb_descriptor_header *)&hidg_interface_desc,
+	(struct usb_descriptor_header *)&hidg_desc,
+	(struct usb_descriptor_header *)&hidg_ss_in_ep_desc,
+	(struct usb_descriptor_header *)&hidg_ss_in_comp_desc,
+	(struct usb_descriptor_header *)&hidg_ss_out_ep_desc,
+	(struct usb_descriptor_header *)&hidg_ss_out_comp_desc,
+	NULL,
+};
+
+static struct usb_descriptor_header *hidg_ss_descriptors_ssreport[] = {
+	(struct usb_descriptor_header *)&hidg_interface_desc,
+	(struct usb_descriptor_header *)&hidg_desc,
+	(struct usb_descriptor_header *)&hidg_ss_in_ep_desc,
+	(struct usb_descriptor_header *)&hidg_ss_in_comp_desc,
+	NULL,
+};
+
+/* High-Speed Support */
+
+static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
+	.bLength		= USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType	= USB_DT_ENDPOINT,
+	.bEndpointAddress	= USB_DIR_IN,
+	.bmAttributes		= USB_ENDPOINT_XFER_INT,
+	/*.wMaxPacketSize	= DYNAMIC */
+	.bInterval		= 4, /* FIXME: Add this field in the
+				      * HID gadget configuration?
+				      * (struct hidg_func_descriptor)
+				      */
+};
+
+static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
+	.bLength		= USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType	= USB_DT_ENDPOINT,
+	.bEndpointAddress	= USB_DIR_OUT,
+	.bmAttributes		= USB_ENDPOINT_XFER_INT,
+	/*.wMaxPacketSize	= DYNAMIC */
+	.bInterval		= 4, /* FIXME: Add this field in the
+				      * HID gadget configuration?
+				      * (struct hidg_func_descriptor)
+				      */
+};
+
+static struct usb_descriptor_header *hidg_hs_descriptors_intout[] = {
+	(struct usb_descriptor_header *)&hidg_interface_desc,
+	(struct usb_descriptor_header *)&hidg_desc,
+	(struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
+	(struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
+	NULL,
+};
+
+static struct usb_descriptor_header *hidg_hs_descriptors_ssreport[] = {
+	(struct usb_descriptor_header *)&hidg_interface_desc,
+	(struct usb_descriptor_header *)&hidg_desc,
+	(struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
+	NULL,
+};
+
+/* Full-Speed Support */
+
+static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
+	.bLength		= USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType	= USB_DT_ENDPOINT,
+	.bEndpointAddress	= USB_DIR_IN,
+	.bmAttributes		= USB_ENDPOINT_XFER_INT,
+	/*.wMaxPacketSize	= DYNAMIC */
+	.bInterval		= 10, /* FIXME: Add this field in the
+				       * HID gadget configuration?
+				       * (struct hidg_func_descriptor)
+				       */
+};
+
+static struct usb_endpoint_descriptor hidg_fs_out_ep_desc = {
+	.bLength		= USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType	= USB_DT_ENDPOINT,
+	.bEndpointAddress	= USB_DIR_OUT,
+	.bmAttributes		= USB_ENDPOINT_XFER_INT,
+	/*.wMaxPacketSize	= DYNAMIC */
+	.bInterval		= 10, /* FIXME: Add this field in the
+				       * HID gadget configuration?
+				       * (struct hidg_func_descriptor)
+				       */
+};
+
+static struct usb_descriptor_header *hidg_fs_descriptors_intout[] = {
+	(struct usb_descriptor_header *)&hidg_interface_desc,
+	(struct usb_descriptor_header *)&hidg_desc,
+	(struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
+	(struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
+	NULL,
+};
+
+static struct usb_descriptor_header *hidg_fs_descriptors_ssreport[] = {
+	(struct usb_descriptor_header *)&hidg_interface_desc,
+	(struct usb_descriptor_header *)&hidg_desc,
+	(struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
+	NULL,
+};
+
+/*-------------------------------------------------------------------------*/
+/*                                 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_intout_read(struct file *file, char __user *buffer,
+				  size_t count, loff_t *ptr)
+{
+	struct f_hidg *hidg = file->private_data;
+	struct f_hidg_req_list *list;
+	struct usb_request *req;
+	unsigned long flags;
+	int ret;
+
+	if (!count)
+		return 0;
+
+	spin_lock_irqsave(&hidg->read_spinlock, flags);
+
+#define READ_COND_INTOUT (!list_empty(&hidg->completed_out_req))
+
+	/* wait for at least one buffer to complete */
+	while (!READ_COND_INTOUT) {
+		spin_unlock_irqrestore(&hidg->read_spinlock, flags);
+		if (file->f_flags & O_NONBLOCK)
+			return -EAGAIN;
+
+		if (wait_event_interruptible(hidg->read_queue, READ_COND_INTOUT))
+			return -ERESTARTSYS;
+
+		spin_lock_irqsave(&hidg->read_spinlock, flags);
+	}
+
+	/* pick the first one */
+	list = list_first_entry(&hidg->completed_out_req,
+				struct f_hidg_req_list, list);
+
+	/*
+	 * Remove this from list to protect it from beign free()
+	 * while host disables our function
+	 */
+	list_del(&list->list);
+
+	req = list->req;
+	count = min_t(unsigned int, count, req->actual - list->pos);
+	spin_unlock_irqrestore(&hidg->read_spinlock, flags);
+
+	/* copy to user outside spinlock */
+	count -= copy_to_user(buffer, req->buf + list->pos, count);
+	list->pos += count;
+
+	/*
+	 * if this request is completely handled and transfered to
+	 * userspace, remove its entry from the list and requeue it
+	 * again. Otherwise, we will revisit it again upon the next
+	 * call, taking into account its current read position.
+	 */
+	if (list->pos == req->actual) {
+		kfree(list);
+
+		req->length = hidg->report_length;
+		ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
+		if (ret < 0) {
+			free_ep_req(hidg->out_ep, req);
+			return ret;
+		}
+	} else {
+		spin_lock_irqsave(&hidg->read_spinlock, flags);
+		list_add(&list->list, &hidg->completed_out_req);
+		spin_unlock_irqrestore(&hidg->read_spinlock, flags);
+
+		wake_up(&hidg->read_queue);
+	}
+
+	return count;
+}
+
+#define READ_COND_SSREPORT (hidg->set_report_buf != NULL)
+
+static ssize_t f_hidg_ssreport_read(struct file *file, char __user *buffer,
+				    size_t count, loff_t *ptr)
+{
+	struct f_hidg *hidg = file->private_data;
+	char *tmp_buf = NULL;
+	unsigned long flags;
+
+	if (!count)
+		return 0;
+
+	spin_lock_irqsave(&hidg->read_spinlock, flags);
+
+	while (!READ_COND_SSREPORT) {
+		spin_unlock_irqrestore(&hidg->read_spinlock, flags);
+		if (file->f_flags & O_NONBLOCK)
+			return -EAGAIN;
+
+		if (wait_event_interruptible(hidg->read_queue, READ_COND_SSREPORT))
+			return -ERESTARTSYS;
+
+		spin_lock_irqsave(&hidg->read_spinlock, flags);
+	}
+
+	count = min_t(unsigned int, count, hidg->set_report_length);
+	tmp_buf = hidg->set_report_buf;
+	hidg->set_report_buf = NULL;
+
+	spin_unlock_irqrestore(&hidg->read_spinlock, flags);
+
+	if (tmp_buf != NULL) {
+		count -= copy_to_user(buffer, tmp_buf, count);
+		kfree(tmp_buf);
+	} else {
+		count = -ENOMEM;
+	}
+
+	wake_up(&hidg->read_queue);
+
+	return count;
+}
+
+static ssize_t f_hidg_read(struct file *file, char __user *buffer,
+			   size_t count, loff_t *ptr)
+{
+	struct f_hidg *hidg = file->private_data;
+
+	if (hidg->use_out_ep)
+		return f_hidg_intout_read(file, buffer, count, ptr);
+	else
+		return f_hidg_ssreport_read(file, buffer, count, ptr);
+}
+
+static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
+	unsigned long flags;
+
+	if (req->status != 0) {
+		ERROR(hidg->func.config->cdev,
+			"End Point Request ERROR: %d\n", req->status);
+	}
+
+	spin_lock_irqsave(&hidg->write_spinlock, flags);
+	hidg->write_pending = 0;
+	spin_unlock_irqrestore(&hidg->write_spinlock, flags);
+	wake_up(&hidg->write_queue);
+}
+
+static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
+			    size_t count, loff_t *offp)
+{
+	struct f_hidg *hidg  = file->private_data;
+	struct usb_request *req;
+	unsigned long flags;
+	ssize_t status = -ENOMEM;
+
+	spin_lock_irqsave(&hidg->write_spinlock, flags);
+
+	if (!hidg->req) {
+		spin_unlock_irqrestore(&hidg->write_spinlock, flags);
+		return -ESHUTDOWN;
+	}
+
+#define WRITE_COND (!hidg->write_pending)
+try_again:
+	/* write queue */
+	while (!WRITE_COND) {
+		spin_unlock_irqrestore(&hidg->write_spinlock, flags);
+		if (file->f_flags & O_NONBLOCK)
+			return -EAGAIN;
+
+		if (wait_event_interruptible_exclusive(
+				hidg->write_queue, WRITE_COND))
+			return -ERESTARTSYS;
+
+		spin_lock_irqsave(&hidg->write_spinlock, flags);
+	}
+
+	hidg->write_pending = 1;
+	req = hidg->req;
+	count  = min_t(unsigned, count, hidg->report_length);
+
+	spin_unlock_irqrestore(&hidg->write_spinlock, flags);
+
+	if (!req) {
+		ERROR(hidg->func.config->cdev, "hidg->req is NULL\n");
+		status = -ESHUTDOWN;
+		goto release_write_pending;
+	}
+
+	status = copy_from_user(req->buf, buffer, count);
+	if (status != 0) {
+		ERROR(hidg->func.config->cdev,
+			"copy_from_user error\n");
+		status = -EINVAL;
+		goto release_write_pending;
+	}
+
+	spin_lock_irqsave(&hidg->write_spinlock, flags);
+
+	/* when our function has been disabled by host */
+	if (!hidg->req) {
+		free_ep_req(hidg->in_ep, req);
+		/*
+		 * TODO
+		 * Should we fail with error here?
+		 */
+		goto try_again;
+	}
+
+	req->status   = 0;
+	req->zero     = 0;
+	req->length   = count;
+	req->complete = f_hidg_req_complete;
+	req->context  = hidg;
+
+	spin_unlock_irqrestore(&hidg->write_spinlock, flags);
+
+	if (!hidg->in_ep->enabled) {
+		ERROR(hidg->func.config->cdev, "in_ep is disabled\n");
+		status = -ESHUTDOWN;
+		goto release_write_pending;
+	}
+
+	status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC);
+	if (status < 0)
+		goto release_write_pending;
+	else
+		status = count;
+
+	return status;
+release_write_pending:
+	spin_lock_irqsave(&hidg->write_spinlock, flags);
+	hidg->write_pending = 0;
+	spin_unlock_irqrestore(&hidg->write_spinlock, flags);
+
+	wake_up(&hidg->write_queue);
+
+	return status;
+}
+
+static __poll_t f_hidg_poll(struct file *file, poll_table *wait)
+{
+	struct f_hidg	*hidg  = file->private_data;
+	__poll_t	ret = 0;
+
+	poll_wait(file, &hidg->read_queue, wait);
+	poll_wait(file, &hidg->write_queue, wait);
+
+	if (WRITE_COND)
+		ret |= EPOLLOUT | EPOLLWRNORM;
+
+	if (hidg->use_out_ep) {
+		if (READ_COND_INTOUT)
+			ret |= EPOLLIN | EPOLLRDNORM;
+	} else {
+		if (READ_COND_SSREPORT)
+			ret |= EPOLLIN | EPOLLRDNORM;
+	}
+
+	return ret;
+}
+
+#undef WRITE_COND
+#undef READ_COND_SSREPORT
+#undef READ_COND_INTOUT
+
+static int f_hidg_release(struct inode *inode, struct file *fd)
+{
+	fd->private_data = NULL;
+	return 0;
+}
+
+static int f_hidg_open(struct inode *inode, struct file *fd)
+{
+	struct f_hidg *hidg =
+		container_of(inode->i_cdev, struct f_hidg, cdev);
+
+	fd->private_data = hidg;
+
+	return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+/*                                usb_function                             */
+
+static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
+						    unsigned length)
+{
+	return alloc_ep_req(ep, length);
+}
+
+static void hidg_intout_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct f_hidg *hidg = (struct f_hidg *) req->context;
+	struct usb_composite_dev *cdev = hidg->func.config->cdev;
+	struct f_hidg_req_list *req_list;
+	unsigned long flags;
+
+	switch (req->status) {
+	case 0:
+		req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
+		if (!req_list) {
+			ERROR(cdev, "Unable to allocate mem for req_list\n");
+			goto free_req;
+		}
+
+		req_list->req = req;
+
+		spin_lock_irqsave(&hidg->read_spinlock, flags);
+		list_add_tail(&req_list->list, &hidg->completed_out_req);
+		spin_unlock_irqrestore(&hidg->read_spinlock, flags);
+
+		wake_up(&hidg->read_queue);
+		break;
+	default:
+		ERROR(cdev, "Set report failed %d\n", req->status);
+		fallthrough;
+	case -ECONNABORTED:		/* hardware forced ep reset */
+	case -ECONNRESET:		/* request dequeued */
+	case -ESHUTDOWN:		/* disconnect from host */
+free_req:
+		free_ep_req(ep, req);
+		return;
+	}
+}
+
+static void hidg_ssreport_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct f_hidg *hidg = (struct f_hidg *)req->context;
+	struct usb_composite_dev *cdev = hidg->func.config->cdev;
+	char *new_buf = NULL;
+	unsigned long flags;
+
+	if (req->status != 0 || req->buf == NULL || req->actual == 0) {
+		ERROR(cdev,
+		      "%s FAILED: status=%d, buf=%p, actual=%d\n",
+		      __func__, req->status, req->buf, req->actual);
+		return;
+	}
+
+	spin_lock_irqsave(&hidg->read_spinlock, flags);
+
+	new_buf = krealloc(hidg->set_report_buf, req->actual, GFP_ATOMIC);
+	if (new_buf == NULL) {
+		spin_unlock_irqrestore(&hidg->read_spinlock, flags);
+		return;
+	}
+	hidg->set_report_buf = new_buf;
+
+	hidg->set_report_length = req->actual;
+	memcpy(hidg->set_report_buf, req->buf, req->actual);
+
+	spin_unlock_irqrestore(&hidg->read_spinlock, flags);
+
+	wake_up(&hidg->read_queue);
+}
+
+static int hidg_setup(struct usb_function *f,
+		const struct usb_ctrlrequest *ctrl)
+{
+	struct f_hidg			*hidg = func_to_hidg(f);
+	struct usb_composite_dev	*cdev = f->config->cdev;
+	struct usb_request		*req  = cdev->req;
+	int status = 0;
+	__u16 value, length;
+
+	value	= __le16_to_cpu(ctrl->wValue);
+	length	= __le16_to_cpu(ctrl->wLength);
+
+	VDBG(cdev,
+	     "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
+	     __func__, ctrl->bRequestType, ctrl->bRequest, value);
+
+	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
+	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
+		  | HID_REQ_GET_REPORT):
+		VDBG(cdev, "get_report\n");
+
+		/* send an empty report */
+		length = min_t(unsigned, length, hidg->report_length);
+		memset(req->buf, 0x0, length);
+
+		goto respond;
+		break;
+
+	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
+		  | HID_REQ_GET_PROTOCOL):
+		VDBG(cdev, "get_protocol\n");
+		length = min_t(unsigned int, length, 1);
+		((u8 *) req->buf)[0] = hidg->protocol;
+		goto respond;
+		break;
+
+	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
+		  | HID_REQ_GET_IDLE):
+		VDBG(cdev, "get_idle\n");
+		length = min_t(unsigned int, length, 1);
+		((u8 *) req->buf)[0] = hidg->idle;
+		goto respond;
+		break;
+
+	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
+		  | HID_REQ_SET_REPORT):
+		VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
+		if (hidg->use_out_ep)
+			goto stall;
+		req->complete = hidg_ssreport_complete;
+		req->context  = hidg;
+		goto respond;
+		break;
+
+	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
+		  | HID_REQ_SET_PROTOCOL):
+		VDBG(cdev, "set_protocol\n");
+		if (value > HID_REPORT_PROTOCOL)
+			goto stall;
+		length = 0;
+		/*
+		 * We assume that programs implementing the Boot protocol
+		 * are also compatible with the Report Protocol
+		 */
+		if (hidg->bInterfaceSubClass == USB_INTERFACE_SUBCLASS_BOOT) {
+			hidg->protocol = value;
+			goto respond;
+		}
+		goto stall;
+		break;
+
+	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
+		  | HID_REQ_SET_IDLE):
+		VDBG(cdev, "set_idle\n");
+		length = 0;
+		hidg->idle = value >> 8;
+		goto respond;
+		break;
+
+	case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
+		  | USB_REQ_GET_DESCRIPTOR):
+		switch (value >> 8) {
+		case HID_DT_HID:
+		{
+			struct hid_descriptor hidg_desc_copy = hidg_desc;
+
+			VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
+			hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
+			hidg_desc_copy.desc[0].wDescriptorLength =
+				cpu_to_le16(hidg->report_desc_length);
+
+			length = min_t(unsigned short, length,
+						   hidg_desc_copy.bLength);
+			memcpy(req->buf, &hidg_desc_copy, length);
+			goto respond;
+			break;
+		}
+		case HID_DT_REPORT:
+			VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
+			length = min_t(unsigned short, length,
+						   hidg->report_desc_length);
+			memcpy(req->buf, hidg->report_desc, length);
+			goto respond;
+			break;
+
+		default:
+			VDBG(cdev, "Unknown descriptor request 0x%x\n",
+				 value >> 8);
+			goto stall;
+			break;
+		}
+		break;
+
+	default:
+		VDBG(cdev, "Unknown request 0x%x\n",
+			 ctrl->bRequest);
+		goto stall;
+		break;
+	}
+
+stall:
+	return -EOPNOTSUPP;
+
+respond:
+	req->zero = 0;
+	req->length = length;
+	status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
+	if (status < 0)
+		ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
+	return status;
+}
+
+static void hidg_disable(struct usb_function *f)
+{
+	struct f_hidg *hidg = func_to_hidg(f);
+	struct f_hidg_req_list *list, *next;
+	unsigned long flags;
+
+	usb_ep_disable(hidg->in_ep);
+
+	if (hidg->out_ep) {
+		usb_ep_disable(hidg->out_ep);
+
+		spin_lock_irqsave(&hidg->read_spinlock, flags);
+		list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
+			free_ep_req(hidg->out_ep, list->req);
+			list_del(&list->list);
+			kfree(list);
+		}
+		spin_unlock_irqrestore(&hidg->read_spinlock, flags);
+	}
+
+	spin_lock_irqsave(&hidg->write_spinlock, flags);
+	if (!hidg->write_pending) {
+		free_ep_req(hidg->in_ep, hidg->req);
+		hidg->write_pending = 1;
+	}
+
+	hidg->req = NULL;
+	spin_unlock_irqrestore(&hidg->write_spinlock, flags);
+}
+
+static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
+{
+	struct usb_composite_dev		*cdev = f->config->cdev;
+	struct f_hidg				*hidg = func_to_hidg(f);
+	struct usb_request			*req_in = NULL;
+	unsigned long				flags;
+	int i, status = 0;
+
+	VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
+
+	if (hidg->in_ep != NULL) {
+		/* restart endpoint */
+		usb_ep_disable(hidg->in_ep);
+
+		status = config_ep_by_speed(f->config->cdev->gadget, f,
+					    hidg->in_ep);
+		if (status) {
+			ERROR(cdev, "config_ep_by_speed FAILED!\n");
+			goto fail;
+		}
+		status = usb_ep_enable(hidg->in_ep);
+		if (status < 0) {
+			ERROR(cdev, "Enable IN endpoint FAILED!\n");
+			goto fail;
+		}
+		hidg->in_ep->driver_data = hidg;
+
+		req_in = hidg_alloc_ep_req(hidg->in_ep, hidg->report_length);
+		if (!req_in) {
+			status = -ENOMEM;
+			goto disable_ep_in;
+		}
+	}
+
+	if (hidg->use_out_ep && hidg->out_ep != NULL) {
+		/* restart endpoint */
+		usb_ep_disable(hidg->out_ep);
+
+		status = config_ep_by_speed(f->config->cdev->gadget, f,
+					    hidg->out_ep);
+		if (status) {
+			ERROR(cdev, "config_ep_by_speed FAILED!\n");
+			goto free_req_in;
+		}
+		status = usb_ep_enable(hidg->out_ep);
+		if (status < 0) {
+			ERROR(cdev, "Enable OUT endpoint FAILED!\n");
+			goto free_req_in;
+		}
+		hidg->out_ep->driver_data = hidg;
+
+		/*
+		 * allocate a bunch of read buffers and queue them all at once.
+		 */
+		for (i = 0; i < hidg->qlen && status == 0; i++) {
+			struct usb_request *req =
+					hidg_alloc_ep_req(hidg->out_ep,
+							  hidg->report_length);
+			if (req) {
+				req->complete = hidg_intout_complete;
+				req->context  = hidg;
+				status = usb_ep_queue(hidg->out_ep, req,
+						      GFP_ATOMIC);
+				if (status) {
+					ERROR(cdev, "%s queue req --> %d\n",
+						hidg->out_ep->name, status);
+					free_ep_req(hidg->out_ep, req);
+				}
+			} else {
+				status = -ENOMEM;
+				goto disable_out_ep;
+			}
+		}
+	}
+
+	if (hidg->in_ep != NULL) {
+		spin_lock_irqsave(&hidg->write_spinlock, flags);
+		hidg->req = req_in;
+		hidg->write_pending = 0;
+		spin_unlock_irqrestore(&hidg->write_spinlock, flags);
+
+		wake_up(&hidg->write_queue);
+	}
+	return 0;
+disable_out_ep:
+	if (hidg->out_ep)
+		usb_ep_disable(hidg->out_ep);
+free_req_in:
+	if (req_in)
+		free_ep_req(hidg->in_ep, req_in);
+
+disable_ep_in:
+	if (hidg->in_ep)
+		usb_ep_disable(hidg->in_ep);
+
+fail:
+	return status;
+}
+
+static const struct file_operations f_hidg_fops = {
+	.owner		= THIS_MODULE,
+	.open		= f_hidg_open,
+	.release	= f_hidg_release,
+	.write		= f_hidg_write,
+	.read		= f_hidg_read,
+	.poll		= f_hidg_poll,
+	.llseek		= noop_llseek,
+};
+
+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;
+	int			status;
+
+	/* 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)
+		goto fail;
+	hidg_interface_desc.bInterfaceNumber = status;
+
+	/* allocate instance-specific endpoints */
+	status = -ENODEV;
+	ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
+	if (!ep)
+		goto fail;
+	hidg->in_ep = ep;
+
+	hidg->out_ep = NULL;
+	if (hidg->use_out_ep) {
+		ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
+		if (!ep)
+			goto fail;
+		hidg->out_ep = ep;
+	}
+
+	/* used only if use_out_ep == 1 */
+	hidg->set_report_buf = NULL;
+
+	/* set descriptor dynamic values */
+	hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
+	hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
+	hidg_interface_desc.bNumEndpoints = hidg->use_out_ep ? 2 : 1;
+	hidg->protocol = HID_REPORT_PROTOCOL;
+	hidg->idle = 1;
+	hidg_ss_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
+	hidg_ss_in_comp_desc.wBytesPerInterval =
+				cpu_to_le16(hidg->report_length);
+	hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
+	hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
+	hidg_ss_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
+	hidg_ss_out_comp_desc.wBytesPerInterval =
+				cpu_to_le16(hidg->report_length);
+	hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
+	hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
+	/*
+	 * We can use hidg_desc struct here but we should not relay
+	 * that its content won't change after returning from this function.
+	 */
+	hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
+	hidg_desc.desc[0].wDescriptorLength =
+		cpu_to_le16(hidg->report_desc_length);
+
+	hidg_hs_in_ep_desc.bEndpointAddress =
+		hidg_fs_in_ep_desc.bEndpointAddress;
+	hidg_hs_out_ep_desc.bEndpointAddress =
+		hidg_fs_out_ep_desc.bEndpointAddress;
+
+	hidg_ss_in_ep_desc.bEndpointAddress =
+		hidg_fs_in_ep_desc.bEndpointAddress;
+	hidg_ss_out_ep_desc.bEndpointAddress =
+		hidg_fs_out_ep_desc.bEndpointAddress;
+
+	if (hidg->use_out_ep)
+		status = usb_assign_descriptors(f,
+			hidg_fs_descriptors_intout,
+			hidg_hs_descriptors_intout,
+			hidg_ss_descriptors_intout,
+			hidg_ss_descriptors_intout);
+	else
+		status = usb_assign_descriptors(f,
+			hidg_fs_descriptors_ssreport,
+			hidg_hs_descriptors_ssreport,
+			hidg_ss_descriptors_ssreport,
+			hidg_ss_descriptors_ssreport);
+
+	if (status)
+		goto fail;
+
+	spin_lock_init(&hidg->write_spinlock);
+	hidg->write_pending = 1;
+	hidg->req = NULL;
+	spin_lock_init(&hidg->read_spinlock);
+	init_waitqueue_head(&hidg->write_queue);
+	init_waitqueue_head(&hidg->read_queue);
+	INIT_LIST_HEAD(&hidg->completed_out_req);
+
+	/* create char device */
+	cdev_init(&hidg->cdev, &f_hidg_fops);
+	status = cdev_device_add(&hidg->cdev, &hidg->dev);
+	if (status)
+		goto fail_free_descs;
+
+	return 0;
+fail_free_descs:
+	usb_free_all_descriptors(f);
+fail:
+	ERROR(f->config->cdev, "hidg_bind FAILED\n");
+	if (hidg->req != NULL)
+		free_ep_req(hidg->in_ep, hidg->req);
+
+	return status;
+}
+
+static inline int hidg_get_minor(void)
+{
+	int ret;
+
+	ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL);
+	if (ret >= HIDG_MINORS) {
+		ida_simple_remove(&hidg_ida, ret);
+		ret = -ENODEV;
+	}
+
+	return ret;
+}
+
+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);
+}
+
+static void hid_attr_release(struct config_item *item)
+{
+	struct f_hid_opts *opts = to_f_hid_opts(item);
+
+	usb_put_function_instance(&opts->func_inst);
+}
+
+static struct configfs_item_operations hidg_item_ops = {
+	.release	= hid_attr_release,
+};
+
+#define F_HID_OPT(name, prec, limit)					\
+static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\
+{									\
+	struct f_hid_opts *opts = to_f_hid_opts(item);			\
+	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 config_item *item,	\
+					 const char *page, size_t len)	\
+{									\
+	struct f_hid_opts *opts = to_f_hid_opts(item);			\
+	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;							\
+}									\
+									\
+CONFIGFS_ATTR(f_hid_opts_, name)
+
+F_HID_OPT(subclass, 8, 255);
+F_HID_OPT(protocol, 8, 255);
+F_HID_OPT(no_out_endpoint, 8, 1);
+F_HID_OPT(report_length, 16, 65535);
+
+static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
+{
+	struct f_hid_opts *opts = to_f_hid_opts(item);
+	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 config_item *item,
+					    const char *page, size_t len)
+{
+	struct f_hid_opts *opts = to_f_hid_opts(item);
+	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;
+}
+
+CONFIGFS_ATTR(f_hid_opts_, report_desc);
+
+static ssize_t f_hid_opts_dev_show(struct config_item *item, char *page)
+{
+	struct f_hid_opts *opts = to_f_hid_opts(item);
+
+	return sprintf(page, "%d:%d\n", major, opts->minor);
+}
+
+CONFIGFS_ATTR_RO(f_hid_opts_, dev);
+
+static struct configfs_attribute *hid_attrs[] = {
+	&f_hid_opts_attr_subclass,
+	&f_hid_opts_attr_protocol,
+	&f_hid_opts_attr_no_out_endpoint,
+	&f_hid_opts_attr_report_length,
+	&f_hid_opts_attr_report_desc,
+	&f_hid_opts_attr_dev,
+	NULL,
+};
+
+static const struct config_item_type hid_func_type = {
+	.ct_item_ops	= &hidg_item_ops,
+	.ct_attrs	= hid_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+static inline void hidg_put_minor(int minor)
+{
+	ida_simple_remove(&hidg_ida, minor);
+}
+
+static void hidg_free_inst(struct usb_function_instance *f)
+{
+	struct f_hid_opts *opts;
+
+	opts = container_of(f, struct f_hid_opts, func_inst);
+
+	mutex_lock(&hidg_ida_lock);
+
+	hidg_put_minor(opts->minor);
+	if (ida_is_empty(&hidg_ida))
+		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 (ida_is_empty(&hidg_ida)) {
+		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 (ida_is_empty(&hidg_ida))
+			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);
+	put_device(&hidg->dev);
+	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);
+
+	cdev_device_del(&hidg->cdev, &hidg->dev);
+
+	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;
+	int ret;
+
+	/* allocate and initialize one new instance */
+	hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
+	if (!hidg)
+		return ERR_PTR(-ENOMEM);
+
+	opts = container_of(fi, struct f_hid_opts, func_inst);
+
+	mutex_lock(&opts->lock);
+	++opts->refcnt;
+
+	device_initialize(&hidg->dev);
+	hidg->dev.release = hidg_release;
+	hidg->dev.class = hidg_class;
+	hidg->dev.devt = MKDEV(major, opts->minor);
+	ret = dev_set_name(&hidg->dev, "hidg%d", opts->minor);
+	if (ret) {
+		--opts->refcnt;
+		mutex_unlock(&opts->lock);
+		return ERR_PTR(ret);
+	}
+
+	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) {
+			put_device(&hidg->dev);
+			--opts->refcnt;
+			mutex_unlock(&opts->lock);
+			return ERR_PTR(-ENOMEM);
+		}
+	}
+	hidg->use_out_ep = !opts->no_out_endpoint;
+
+	mutex_unlock(&opts->lock);
+
+	hidg->func.name    = "hid";
+	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 be made configurable at some point */
+	hidg->qlen	   = 4;
+
+	return &hidg->func;
+}
+
+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) {
+		class_destroy(hidg_class);
+		hidg_class = NULL;
+		return status;
+	}
+
+	major = MAJOR(dev);
+	minors = count;
+
+	return 0;
+}
+
+void ghid_cleanup(void)
+{
+	if (major) {
+		unregister_chrdev_region(MKDEV(major, 0), minors);
+		major = minors = 0;
+	}
+
+	class_destroy(hidg_class);
+	hidg_class = NULL;
+}