usb: gadget: Introduce qdss function driver

The QDSS function driver supports high throughput debug information
delivery from the QDSS core to the host via the USB port.

Change-Id: Ia9397944d39d767c1200ad87aac67d5627233282
Signed-off-by: Shimrit Malichi <smalichi@codeaurora.org>
diff --git a/drivers/usb/gadget/f_qdss.c b/drivers/usb/gadget/f_qdss.c
new file mode 100644
index 0000000..0c81904
--- /dev/null
+++ b/drivers/usb/gadget/f_qdss.c
@@ -0,0 +1,817 @@
+/*
+ * f_qdss.c -- QDSS function Driver
+ *
+ * Copyright (c) 2012, Code Aurora Forum. All rights reserved.
+
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/usb/usb_qdss.h>
+#include <linux/usb/msm_hsusb.h>
+
+#include "f_qdss.h"
+#include "u_qdss.c"
+
+static DEFINE_SPINLOCK(d_lock);
+static LIST_HEAD(usb_qdss_ch_list);
+
+static struct usb_interface_descriptor qdss_data_intf_desc = {
+	.bLength            =	sizeof qdss_data_intf_desc,
+	.bDescriptorType    =	USB_DT_INTERFACE,
+	.bAlternateSetting  =   0,
+	.bNumEndpoints      =	1,
+	.bInterfaceClass    =	0xff,
+	.bInterfaceSubClass =	0xff,
+	.bInterfaceProtocol =	0xff,
+};
+
+static struct usb_endpoint_descriptor qdss_hs_data_desc = {
+	.bLength              =	 USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType      =	 USB_DT_ENDPOINT,
+	.bEndpointAddress     =	 USB_DIR_IN,
+	.bmAttributes         =	 USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize       =	 __constant_cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor qdss_ss_data_desc = {
+	.bLength              =	 USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType      =	 USB_DT_ENDPOINT,
+	.bEndpointAddress     =	 USB_DIR_IN,
+	.bmAttributes         =  USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize       =	 __constant_cpu_to_le16(1024),
+};
+
+static struct usb_ss_ep_comp_descriptor qdss_data_ep_comp_desc = {
+	.bLength              =	 sizeof qdss_data_ep_comp_desc,
+	.bDescriptorType      =	 USB_DT_SS_ENDPOINT_COMP,
+	.bMaxBurst            =	 1,
+	.bmAttributes         =	 0,
+	.wBytesPerInterval    =	 0,
+};
+
+static struct usb_interface_descriptor qdss_ctrl_intf_desc = {
+	.bLength            =	sizeof qdss_ctrl_intf_desc,
+	.bDescriptorType    =	USB_DT_INTERFACE,
+	.bAlternateSetting  =   0,
+	.bNumEndpoints      =	2,
+	.bInterfaceClass    =	0xff,
+	.bInterfaceSubClass =	0xff,
+	.bInterfaceProtocol =	0xff,
+};
+
+static struct usb_endpoint_descriptor qdss_hs_ctrl_in_desc = {
+	.bLength            =	USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType    =	USB_DT_ENDPOINT,
+	.bEndpointAddress   =	USB_DIR_IN,
+	.bmAttributes       =	USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize     =	__constant_cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor qdss_ss_ctrl_in_desc = {
+	.bLength            =	USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType    =	USB_DT_ENDPOINT,
+	.bEndpointAddress   =	USB_DIR_IN,
+	.bmAttributes       =	USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize     =	__constant_cpu_to_le16(1024),
+};
+
+static struct usb_endpoint_descriptor qdss_hs_ctrl_out_desc = {
+	.bLength            =	USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType    =	USB_DT_ENDPOINT,
+	.bEndpointAddress   =	USB_DIR_OUT,
+	.bmAttributes       =	USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize     =	__constant_cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor qdss_ss_ctrl_out_desc = {
+	.bLength            =	USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType    =	USB_DT_ENDPOINT,
+	.bEndpointAddress   =	USB_DIR_OUT,
+	.bmAttributes       =	USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize     =	__constant_cpu_to_le16(0x400),
+};
+
+static struct usb_ss_ep_comp_descriptor qdss_ctrl_in_ep_comp_desc = {
+	.bLength            =	sizeof qdss_ctrl_in_ep_comp_desc,
+	.bDescriptorType    =	USB_DT_SS_ENDPOINT_COMP,
+	.bMaxBurst          =	0,
+	.bmAttributes       =	0,
+	.wBytesPerInterval  =	0,
+};
+
+static struct usb_ss_ep_comp_descriptor qdss_ctrl_out_ep_comp_desc = {
+	.bLength            =	sizeof qdss_ctrl_out_ep_comp_desc,
+	.bDescriptorType    =	USB_DT_SS_ENDPOINT_COMP,
+	.bMaxBurst          =	0,
+	.bmAttributes       =	0,
+	.wBytesPerInterval  =	0,
+};
+
+static struct usb_descriptor_header *qdss_hs_desc[] = {
+	(struct usb_descriptor_header *) &qdss_data_intf_desc,
+	(struct usb_descriptor_header *) &qdss_hs_data_desc,
+	(struct usb_descriptor_header *) &qdss_ctrl_intf_desc,
+	(struct usb_descriptor_header *) &qdss_hs_ctrl_in_desc,
+	(struct usb_descriptor_header *) &qdss_hs_ctrl_out_desc,
+	NULL,
+};
+
+static struct usb_descriptor_header *qdss_ss_desc[] = {
+	(struct usb_descriptor_header *) &qdss_data_intf_desc,
+	(struct usb_descriptor_header *) &qdss_ss_data_desc,
+	(struct usb_descriptor_header *) &qdss_data_ep_comp_desc,
+	(struct usb_descriptor_header *) &qdss_ctrl_intf_desc,
+	(struct usb_descriptor_header *) &qdss_ss_ctrl_in_desc,
+	(struct usb_descriptor_header *) &qdss_ctrl_in_ep_comp_desc,
+	(struct usb_descriptor_header *) &qdss_ss_ctrl_out_desc,
+	(struct usb_descriptor_header *) &qdss_ctrl_out_ep_comp_desc,
+	NULL,
+};
+
+/* string descriptors: */
+#define QDSS_DATA_IDX	0
+#define QDSS_CTRL_IDX	1
+
+static struct usb_string qdss_string_defs[] = {
+	[QDSS_DATA_IDX].s = "QDSS DATA",
+	[QDSS_CTRL_IDX].s = "QDSS CTRL",
+	{}, /* end of list */
+};
+
+static struct usb_gadget_strings qdss_string_table = {
+	.language =		0x0409,
+	.strings =		qdss_string_defs,
+};
+
+static struct usb_gadget_strings *qdss_strings[] = {
+	&qdss_string_table,
+	NULL,
+};
+
+static inline struct f_qdss *func_to_qdss(struct usb_function *f)
+{
+	return container_of(f, struct f_qdss, function);
+}
+
+/*----------------------------------------------------------------------*/
+
+static void qdss_ctrl_write_complete(struct usb_ep *ep,
+	struct usb_request *req)
+{
+	struct f_qdss *qdss = ep->driver_data;
+	struct qdss_request *d_req = req->context;
+	unsigned long flags;
+
+	pr_debug("qdss_ctrl_write_complete\n");
+
+	if (!req->status) {
+		/* send zlp */
+		if ((req->length >= ep->maxpacket) &&
+				((req->length % ep->maxpacket) == 0)) {
+			req->length = 0;
+			d_req->actual = req->actual;
+			d_req->status = req->status;
+			usb_ep_queue(qdss->ctrl_in, req, GFP_ATOMIC);
+			return;
+		}
+	}
+
+	spin_lock_irqsave(&qdss->lock, flags);
+	list_add_tail(&req->list, &qdss->ctrl_write_pool);
+	if (req->length != 0) {
+		d_req->actual = req->actual;
+		d_req->status = req->status;
+	}
+	spin_unlock_irqrestore(&qdss->lock, flags);
+
+	if (qdss->ch.notify)
+		qdss->ch.notify(qdss->ch.priv, USB_QDSS_CTRL_WRITE_DONE, d_req,
+			NULL);
+}
+
+static void qdss_ctrl_read_complete(struct usb_ep *ep,
+	struct usb_request *req)
+{
+	struct f_qdss *qdss = ep->driver_data;
+	struct qdss_request *d_req = req->context;
+	unsigned long flags;
+
+	pr_debug("qdss_ctrl_read_complete\n");
+
+	d_req->actual = req->actual;
+	d_req->status = req->status;
+
+	spin_lock_irqsave(&qdss->lock, flags);
+	list_add_tail(&req->list, &qdss->ctrl_read_pool);
+	spin_unlock_irqrestore(&qdss->lock, flags);
+
+	if (qdss->ch.notify)
+		qdss->ch.notify(qdss->ch.priv, USB_QDSS_CTRL_READ_DONE, d_req,
+			NULL);
+}
+
+void usb_qdss_free_req(struct usb_qdss_ch *ch)
+{
+	struct f_qdss *qdss;
+	struct usb_request *req;
+	struct list_head *act, *tmp;
+
+	pr_debug("usb_qdss_free_req\n");
+
+	qdss = ch->priv_usb;
+	if (!qdss) {
+		pr_err("usb_qdss_free_req: qdss ctx is NULL\n");
+		return;
+	}
+
+	list_for_each_safe(act, tmp, &qdss->ctrl_write_pool) {
+		req = list_entry(act, struct usb_request, list);
+		list_del(&req->list);
+		usb_ep_free_request(qdss->ctrl_in, req);
+	}
+
+	list_for_each_safe(act, tmp, &qdss->ctrl_read_pool) {
+		req = list_entry(act, struct usb_request, list);
+		list_del(&req->list);
+		usb_ep_free_request(qdss->ctrl_out, req);
+	}
+}
+EXPORT_SYMBOL(usb_qdss_free_req);
+
+int usb_qdss_alloc_req(struct usb_qdss_ch *ch, int no_write_buf,
+	int no_read_buf)
+{
+	struct f_qdss *qdss = ch->priv_usb;
+	struct usb_request *req;
+	int i;
+
+	pr_debug("usb_qdss_alloc_req\n");
+
+	if (no_write_buf <= 0 || no_read_buf <= 0 || !qdss) {
+		pr_err("usb_qdss_alloc_req: missing params\n");
+		return -ENODEV;
+	}
+
+	for (i = 0; i < no_write_buf; i++) {
+		req = usb_ep_alloc_request(qdss->ctrl_in, GFP_ATOMIC);
+		if (!req) {
+			pr_err("usb_qdss_alloc_req: ctrl_in allocation err\n");
+			goto fail;
+		}
+		req->complete = qdss_ctrl_write_complete;
+		list_add_tail(&req->list, &qdss->ctrl_write_pool);
+	}
+
+	for (i = 0; i < no_read_buf; i++) {
+		req = usb_ep_alloc_request(qdss->ctrl_out, GFP_ATOMIC);
+		if (!req) {
+			pr_err("usb_qdss_alloc_req:ctrl_out allocation err\n");
+			goto fail;
+		}
+		req->complete = qdss_ctrl_read_complete;
+		list_add_tail(&req->list, &qdss->ctrl_read_pool);
+	}
+
+	return 0;
+
+fail:
+	usb_qdss_free_req(ch);
+	return -ENOMEM;
+}
+EXPORT_SYMBOL(usb_qdss_alloc_req);
+
+static void clear_eps(struct usb_function *f)
+{
+	struct f_qdss *qdss = func_to_qdss(f);
+
+	pr_debug("clear_eps\n");
+
+	if (qdss->ctrl_in)
+		qdss->ctrl_in->driver_data = NULL;
+	if (qdss->ctrl_out)
+		qdss->ctrl_out->driver_data = NULL;
+	if (qdss->data)
+		qdss->data->driver_data = NULL;
+}
+
+static void clear_desc(struct usb_gadget *gadget, struct usb_function *f)
+{
+	pr_debug("clear_desc\n");
+
+	if (gadget_is_superspeed(gadget) && f->ss_descriptors)
+		usb_free_descriptors(f->ss_descriptors);
+
+	if (gadget_is_dualspeed(gadget) && f->hs_descriptors)
+		usb_free_descriptors(f->hs_descriptors);
+}
+
+static int qdss_bind(struct usb_configuration *c, struct usb_function *f)
+{
+	struct usb_gadget *gadget = c->cdev->gadget;
+	struct f_qdss *qdss = func_to_qdss(f);
+	struct usb_ep *ep;
+	int iface;
+
+	pr_debug("qdss_bind\n");
+
+	if (!gadget_is_dualspeed(gadget) && !gadget_is_superspeed(gadget)) {
+		pr_err("qdss_bind: full-speed is not supported\n");
+		return -ENOTSUPP;
+	}
+
+	/* Allocate data I/F */
+	iface = usb_interface_id(c, f);
+	if (iface < 0) {
+		pr_err("interface allocation error\n");
+		return iface;
+	}
+	qdss_data_intf_desc.bInterfaceNumber = iface;
+	qdss->data_iface_id = iface;
+
+	/* Allocate ctrl I/F */
+	iface = usb_interface_id(c, f);
+	if (iface < 0) {
+		pr_err("interface allocation error\n");
+		return iface;
+	}
+	qdss_ctrl_intf_desc.bInterfaceNumber = iface;
+	qdss->ctrl_iface_id = iface;
+
+	ep = usb_ep_autoconfig_ss(gadget, &qdss_ss_data_desc,
+		&qdss_data_ep_comp_desc);
+	if (!ep) {
+		pr_err("ep_autoconfig error\n");
+		goto fail;
+	}
+	qdss->data = ep;
+	ep->driver_data = qdss;
+
+	ep = usb_ep_autoconfig_ss(gadget, &qdss_ss_ctrl_in_desc,
+		&qdss_ctrl_in_ep_comp_desc);
+	if (!ep) {
+		pr_err("ep_autoconfig error\n");
+		goto fail;
+	}
+	qdss->ctrl_in = ep;
+	ep->driver_data = qdss;
+
+	ep = usb_ep_autoconfig_ss(gadget, &qdss_ss_ctrl_out_desc,
+		&qdss_ctrl_out_ep_comp_desc);
+	if (!ep) {
+		pr_err("ep_autoconfig error\n");
+		goto fail;
+	}
+	qdss->ctrl_out = ep;
+	ep->driver_data = qdss;
+
+	/*update descriptors*/
+	qdss_hs_data_desc.bEndpointAddress =
+		qdss_ss_data_desc.bEndpointAddress;
+	qdss_hs_ctrl_in_desc.bEndpointAddress =
+		qdss_ss_ctrl_in_desc.bEndpointAddress;
+	qdss_hs_ctrl_out_desc.bEndpointAddress =
+		qdss_ss_ctrl_out_desc.bEndpointAddress;
+
+	f->hs_descriptors = usb_copy_descriptors(qdss_hs_desc);
+	if (!f->hs_descriptors) {
+		pr_err("usb_copy_descriptors error\n");
+		goto fail;
+	}
+
+	/* update ss descriptors */
+	if (gadget_is_superspeed(gadget)) {
+		f->ss_descriptors = usb_copy_descriptors(qdss_ss_desc);
+		if (!f->ss_descriptors) {
+			pr_err("usb_copy_descriptors error\n");
+			goto fail;
+		}
+	}
+
+	return 0;
+fail:
+	clear_eps(f);
+	clear_desc(gadget, f);
+	return -ENOTSUPP;
+}
+
+
+static void qdss_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+	pr_debug("qdss_unbind\n");
+
+	clear_desc(c->cdev->gadget, f);
+}
+
+static void qdss_eps_disable(struct usb_function *f)
+{
+	struct f_qdss  *qdss = func_to_qdss(f);
+
+	pr_debug("qdss_eps_disable\n");
+
+	if (qdss->ctrl_in_enabled) {
+		usb_ep_disable(qdss->ctrl_in);
+		qdss->ctrl_in_enabled = 0;
+		qdss->ctrl_in->driver_data = NULL;
+	}
+
+	if (qdss->ctrl_out_enabled) {
+		usb_ep_disable(qdss->ctrl_out);
+		qdss->ctrl_out_enabled = 0;
+		qdss->ctrl_out->driver_data = NULL;
+	}
+
+	if (qdss->data_enabled) {
+		usb_ep_disable(qdss->data);
+		qdss->data_enabled = 0;
+		qdss->data->driver_data = NULL;
+	}
+}
+
+static void qdss_disable(struct usb_function *f)
+{
+	struct f_qdss	*qdss = func_to_qdss(f);
+	unsigned long flags;
+	int status;
+
+	pr_debug("qdss_disable\n");
+
+	spin_lock_irqsave(&qdss->lock, flags);
+	qdss->usb_connected = 0;
+	spin_unlock_irqrestore(&qdss->lock, flags);
+
+	/*cancell all active xfers*/
+	qdss_eps_disable(f);
+
+	/* notify qdss to cancell all active transfers*/
+	if (qdss->ch.notify) {
+		qdss->ch.notify(qdss->ch.priv, USB_QDSS_DISCONNECT, NULL,
+			NULL);
+		/* If the app was never started, we can skip USB BAM reset */
+		status = set_qdss_data_connection(qdss->data,
+			qdss->data->address, 0);
+		if (status)
+			pr_err("qdss_disable error");
+	}
+}
+
+static void usb_qdss_work_func(struct work_struct *work)
+{
+	struct f_qdss *qdss = container_of(work, struct f_qdss, qdss_work);
+	int status;
+
+	pr_debug("usb_qdss_work_func\n");
+
+	status = init_data(qdss->data);
+	if (status) {
+		pr_err("init_data error");
+		return;
+	}
+
+	status = set_qdss_data_connection(qdss->data,
+		qdss->data->address, 1);
+	if (status) {
+		pr_err("set_qdss_data_connection error");
+		return;
+	}
+	if (qdss->ch.notify)
+		qdss->ch.notify(qdss->ch.priv, USB_QDSS_CONNECT, NULL,
+			&qdss->ch);
+
+	status = send_sps_req(qdss->data);
+	if (status) {
+		pr_err("send_sps_req error\n");
+		return;
+	}
+}
+
+static int qdss_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
+{
+	struct f_qdss  *qdss = func_to_qdss(f);
+	struct usb_gadget *gadget = f->config->cdev->gadget;
+	struct usb_qdss_ch *ch = &qdss->ch;
+	int ret = 0;
+
+	pr_debug("qdss_set_alt\n");
+
+	if (alt != 0)
+		goto fail;
+
+	if (gadget->speed != USB_SPEED_SUPER &&
+		gadget->speed != USB_SPEED_HIGH) {
+			pr_err("qdss_st_alt: qdss supportes HS or SS only\n");
+			goto fail;
+	}
+
+	if (intf == qdss->data_iface_id) {
+		if (config_ep_by_speed(gadget, f, qdss->data))
+			return -EINVAL;
+
+		ret = usb_ep_enable(qdss->data);
+		if (ret)
+			goto fail;
+
+		qdss->data->driver_data = qdss;
+		qdss->data_enabled = 1;
+
+	} else if (intf == qdss->ctrl_iface_id) {
+		if (config_ep_by_speed(gadget, f, qdss->ctrl_in))
+			return -EINVAL;
+
+		ret = usb_ep_enable(qdss->ctrl_in);
+		if (ret)
+			goto fail;
+
+		qdss->ctrl_in->driver_data = qdss;
+		qdss->ctrl_in_enabled = 1;
+
+		if (config_ep_by_speed(gadget, f, qdss->ctrl_out))
+			return -EINVAL;
+
+		ret = usb_ep_enable(qdss->ctrl_out);
+		if (ret)
+			goto fail;
+
+		qdss->ctrl_out->driver_data = qdss;
+		qdss->ctrl_out_enabled = 1;
+	}
+
+	if (qdss->ctrl_out_enabled && qdss->ctrl_in_enabled &&
+		qdss->data_enabled)
+		qdss->usb_connected = 1;
+
+	if (qdss->usb_connected && ch->app_conn)
+		schedule_work(&qdss->qdss_work);
+
+	return 0;
+fail:
+	pr_err("qdss_set_alt failed\n");
+	qdss_eps_disable(f);
+	return ret;
+}
+
+static int qdss_bind_config(struct usb_configuration *c, const char *name)
+{
+	struct f_qdss *qdss;
+	int status, found = 0;
+	struct usb_qdss_ch *ch;
+	unsigned long flags;
+
+	pr_debug("qdss_bind_config\n");
+
+	if (qdss_string_defs[QDSS_DATA_IDX].id == 0) {
+		status = usb_string_id(c->cdev);
+		if (status < 0)
+			return status;
+		qdss_string_defs[QDSS_DATA_IDX].id = status;
+		qdss_data_intf_desc.iInterface = status;
+
+		status = usb_string_id(c->cdev);
+		if (status < 0)
+			return status;
+		qdss_string_defs[QDSS_CTRL_IDX].id = status;
+		qdss_ctrl_intf_desc.iInterface = status;
+	}
+
+	spin_lock_irqsave(&d_lock, flags);
+	list_for_each_entry(ch, &usb_qdss_ch_list, list) {
+		if (!strncmp(name, ch->name, sizeof(ch->name))) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (!found) {
+		pr_debug("qdss_bind_config allocating channel\n");
+		qdss = kzalloc(sizeof *qdss, GFP_ATOMIC);
+		if (!qdss) {
+			pr_err("qdss_bind_config: allocating channel failed\n");
+			spin_unlock_irqrestore(&d_lock, flags);
+			return -ENOMEM;
+		}
+
+		ch = &qdss->ch;
+		ch->name = name;
+		list_add_tail(&ch->list, &usb_qdss_ch_list);
+	} else {
+		qdss = container_of(ch, struct f_qdss, ch);
+		ch->priv_usb = qdss;
+	}
+	spin_unlock_irqrestore(&d_lock, flags);
+	qdss->cdev = c->cdev;
+	qdss->function.name = name;
+	qdss->function.descriptors = qdss_hs_desc;
+	qdss->function.hs_descriptors = qdss_hs_desc;
+	qdss->function.strings = qdss_strings;
+	qdss->function.bind = qdss_bind;
+	qdss->function.unbind = qdss_unbind;
+	qdss->function.set_alt = qdss_set_alt;
+	qdss->function.disable = qdss_disable;
+	INIT_LIST_HEAD(&qdss->ctrl_read_pool);
+	INIT_LIST_HEAD(&qdss->ctrl_write_pool);
+	INIT_WORK(&qdss->qdss_work, usb_qdss_work_func);
+
+	status = usb_add_function(c, &qdss->function);
+	if (status) {
+		pr_err("qdss usb_add_function failed\n");
+		ch->priv_usb = NULL;
+		kfree(qdss);
+	}
+
+	return status;
+}
+
+int usb_qdss_ctrl_read(struct usb_qdss_ch *ch, struct qdss_request *d_req)
+{
+	struct f_qdss *qdss = ch->priv_usb;
+	unsigned long flags;
+	struct usb_request *req = NULL;
+
+	pr_debug("usb_qdss_ctrl_read\n");
+
+	if (!qdss)
+		return -ENODEV;
+
+	spin_lock_irqsave(&qdss->lock, flags);
+
+	if (qdss->usb_connected == 0) {
+		spin_unlock_irqrestore(&qdss->lock, flags);
+		return -EIO;
+	}
+
+	if (list_empty(&qdss->ctrl_read_pool)) {
+		spin_unlock_irqrestore(&qdss->lock, flags);
+		pr_err("error: usb_qdss_ctrl_read list is empty\n");
+		return -EAGAIN;
+	}
+
+	req = list_first_entry(&qdss->ctrl_read_pool, struct usb_request, list);
+	list_del(&req->list);
+	spin_unlock_irqrestore(&qdss->lock, flags);
+
+	req->buf = d_req->buf;
+	req->length = d_req->length;
+	req->context = d_req;
+
+	if (usb_ep_queue(qdss->ctrl_out, req, GFP_ATOMIC)) {
+		/* If error add the link to linked list again*/
+		spin_lock_irqsave(&qdss->lock, flags);
+		list_add_tail(&req->list, &qdss->ctrl_read_pool);
+		spin_unlock_irqrestore(&qdss->lock, flags);
+		pr_err("qdss usb_ep_queue failed\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(usb_qdss_ctrl_read);
+
+int usb_qdss_ctrl_write(struct usb_qdss_ch *ch, struct qdss_request *d_req)
+{
+	struct f_qdss *qdss = ch->priv_usb;
+	unsigned long flags;
+	struct usb_request *req = NULL;
+
+	pr_debug("usb_qdss_ctrl_write\n");
+
+	if (!qdss)
+		return -ENODEV;
+
+	spin_lock_irqsave(&qdss->lock, flags);
+
+	if (qdss->usb_connected == 0) {
+		spin_unlock_irqrestore(&qdss->lock, flags);
+		return -EIO;
+	}
+
+	if (list_empty(&qdss->ctrl_write_pool)) {
+		pr_err("error: usb_qdss_ctrl_write list is empty\n");
+		spin_unlock_irqrestore(&qdss->lock, flags);
+		return -EAGAIN;
+	}
+
+	req = list_first_entry(&qdss->ctrl_write_pool, struct usb_request,
+		list);
+	list_del(&req->list);
+	spin_unlock_irqrestore(&qdss->lock, flags);
+
+	req->buf = d_req->buf;
+	req->length = d_req->length;
+	req->context = d_req;
+	if (usb_ep_queue(qdss->ctrl_in, req, GFP_ATOMIC)) {
+		spin_lock_irqsave(&qdss->lock, flags);
+		list_add_tail(&req->list, &qdss->ctrl_write_pool);
+		spin_unlock_irqrestore(&qdss->lock, flags);
+		pr_err("qdss usb_ep_queue failed\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(usb_qdss_ctrl_write);
+
+struct usb_qdss_ch *usb_qdss_open(const char *name, void *priv,
+	void (*notify)(void *, unsigned, struct qdss_request *,
+		struct usb_qdss_ch *))
+{
+	struct usb_qdss_ch *ch;
+	struct f_qdss *qdss;
+	unsigned long flags;
+	int found = 0;
+
+	pr_debug("usb_qdss_open\n");
+
+	if (!notify) {
+		pr_err("usb_qdss_open: notification func is missing\n");
+		return NULL;
+	}
+
+	spin_lock_irqsave(&d_lock, flags);
+	/* Check if we already have a channel with this name */
+	list_for_each_entry(ch, &usb_qdss_ch_list, list) {
+		if (!strncmp(name, ch->name, sizeof(ch->name))) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (!found) {
+		pr_debug("usb_qdss_open: allocation qdss ctx\n");
+		qdss = kzalloc(sizeof(*qdss), GFP_ATOMIC);
+		if (!qdss) {
+			spin_unlock_irqrestore(&d_lock, flags);
+			return ERR_PTR(-ENOMEM);
+		}
+		ch = &qdss->ch;
+		list_add_tail(&ch->list, &usb_qdss_ch_list);
+	} else {
+		pr_debug("usb_qdss_open: qdss ctx found\n");
+		qdss = container_of(ch, struct f_qdss, ch);
+		ch->priv_usb = qdss;
+	}
+
+	ch->name = name;
+	ch->priv = priv;
+	ch->notify = notify;
+	ch->app_conn = 1;
+	spin_unlock_irqrestore(&d_lock, flags);
+
+	/* the case USB cabel was connected befor qdss called  qdss_open*/
+	if (qdss->usb_connected == 1)
+		schedule_work(&qdss->qdss_work);
+
+	return ch;
+}
+EXPORT_SYMBOL(usb_qdss_open);
+
+void usb_qdss_close(struct usb_qdss_ch *ch)
+{
+	struct f_qdss *qdss = ch->priv_usb;
+	unsigned long flags;
+
+	pr_debug("usb_qdss_close\n");
+
+	spin_lock_irqsave(&d_lock, flags);
+	/*free not used reqests*/
+	usb_qdss_free_req(ch);
+	usb_ep_dequeue(qdss->data, qdss->endless_req);
+	qdss->endless_req = NULL;
+	spin_unlock_irqrestore(&d_lock, flags);
+}
+EXPORT_SYMBOL(usb_qdss_close);
+
+static void qdss_cleanup(void)
+{
+	struct f_qdss *qdss;
+	struct list_head *act, *tmp;
+	struct usb_qdss_ch *_ch;
+	unsigned long flags;
+
+	pr_debug("qdss_cleanup\n");
+
+	list_for_each_safe(act, tmp, &usb_qdss_ch_list) {
+		_ch = list_entry(act, struct usb_qdss_ch, list);
+		qdss = container_of(_ch, struct f_qdss, ch);
+		spin_lock_irqsave(&d_lock, flags);
+
+		if (!_ch->priv) {
+			list_del(&_ch->list);
+			kfree(qdss);
+		}
+		spin_unlock_irqrestore(&d_lock, flags);
+	}
+}
+
+static int qdss_setup(void)
+{
+	return 0;
+}
+