recipes-kernel: add MOST driver kernel modules

This commit adds the recipes-kernel directory to the meta-agl-demo
layer. It is needed to add the MOST driver to the AGL layer and have
it compiled as out-of-tree modules.

Change-Id: I38174a2f9a59b0424cfaf2f85f059550422f58f2
Signed-off-by: Christian Gromm <christian.gromm@microchip.com>

3 files changed, 1795 insertions, 0 deletions

diff --git a/recipes-kernel/hdm-usb/files/COPYING b/recipes-kernel/hdm-usb/files/COPYING
new file mode 100644
index 000000000..6d45519c8
--- /dev/null
+++ b/recipes-kernel/hdm-usb/files/COPYING
@@ -0,0 +1,340 @@
+		    GNU GENERAL PUBLIC LICENSE
+		       Version 2, June 1991
+
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+                       51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
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diff --git a/recipes-kernel/hdm-usb/files/Makefile b/recipes-kernel/hdm-usb/files/Makefile
new file mode 100644
index 000000000..0714f6b73
--- /dev/null
+++ b/recipes-kernel/hdm-usb/files/Makefile
@@ -0,0 +1,17 @@
+# Makefile
+#
+
+SRC := $(shell pwd)
+
+obj-m += hdm_usb.o
+CFLAGS_hdm_usb.o := -I$(src)/../../aim-network/files/ -I$(src)/../../mostcore/files 
+
+all:
+	$(MAKE) -C $(KERNEL_SRC) M=$(SRC) modules
+
+modules_install:
+	$(MAKE) -C $(KERNEL_SRC) M=$(SRC) modules_install
+
+clean:
+	$(MAKE) -C $(KERNEL_SRC) M=$(SRC) clean
+
diff --git a/recipes-kernel/hdm-usb/files/hdm_usb.c b/recipes-kernel/hdm-usb/files/hdm_usb.c
new file mode 100644
index 000000000..41690f801
--- /dev/null
+++ b/recipes-kernel/hdm-usb/files/hdm_usb.c
@@ -0,0 +1,1438 @@
+/*
+ * hdm_usb.c - Hardware dependent module for USB
+ *
+ * Copyright (C) 2013-2015 Microchip Technology Germany II GmbH & Co. KG
+ *
+ * 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.
+ *
+ * This file is licensed under GPLv2.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/usb.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/completion.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/sysfs.h>
+#include <linux/dma-mapping.h>
+#include <linux/etherdevice.h>
+#include <linux/uaccess.h>
+#include "mostcore.h"
+#include "networking.h"
+
+#define USB_MTU			512
+#define NO_ISOCHRONOUS_URB	0
+#define AV_PACKETS_PER_XACT	2
+#define BUF_CHAIN_SIZE		0xFFFF
+#define MAX_NUM_ENDPOINTS	30
+#define MAX_SUFFIX_LEN		10
+#define MAX_STRING_LEN		80
+#define MAX_BUF_SIZE		0xFFFF
+#define CEILING(x, y)		(((x) + (y) - 1) / (y))
+
+#define USB_VENDOR_ID_SMSC	0x0424  /* VID: SMSC */
+#define USB_DEV_ID_BRDG		0xC001  /* PID: USB Bridge */
+#define USB_DEV_ID_INIC		0xCF18  /* PID: USB INIC */
+#define HW_RESYNC		0x0000
+/* DRCI Addresses */
+#define DRCI_REG_NI_STATE	0x0100
+#define DRCI_REG_PACKET_BW	0x0101
+#define DRCI_REG_NODE_ADDR	0x0102
+#define DRCI_REG_NODE_POS	0x0103
+#define DRCI_REG_MEP_FILTER	0x0140
+#define DRCI_REG_HASH_TBL0	0x0141
+#define DRCI_REG_HASH_TBL1	0x0142
+#define DRCI_REG_HASH_TBL2	0x0143
+#define DRCI_REG_HASH_TBL3	0x0144
+#define DRCI_REG_HW_ADDR_HI	0x0145
+#define DRCI_REG_HW_ADDR_MI	0x0146
+#define DRCI_REG_HW_ADDR_LO	0x0147
+#define DRCI_REG_BASE		0x1100
+#define DRCI_COMMAND		0x02
+#define DRCI_READ_REQ		0xA0
+#define DRCI_WRITE_REQ		0xA1
+
+/**
+ * struct buf_anchor - used to create a list of pending URBs
+ * @urb: pointer to USB request block
+ * @clear_work_obj:
+ * @list: linked list
+ * @urb_completion:
+ */
+struct buf_anchor {
+	struct urb *urb;
+	struct work_struct clear_work_obj;
+	struct list_head list;
+	struct completion urb_compl;
+};
+
+#define to_buf_anchor(w) container_of(w, struct buf_anchor, clear_work_obj)
+
+/**
+ * struct most_dci_obj - Direct Communication Interface
+ * @kobj:position in sysfs
+ * @usb_device: pointer to the usb device
+ */
+struct most_dci_obj {
+	struct kobject kobj;
+	struct usb_device *usb_device;
+};
+
+#define to_dci_obj(p) container_of(p, struct most_dci_obj, kobj)
+
+/**
+ * struct most_dev - holds all usb interface specific stuff
+ * @parent: parent object in sysfs
+ * @usb_device: pointer to usb device
+ * @iface: hardware interface
+ * @cap: channel capabilities
+ * @conf: channel configuration
+ * @dci: direct communication interface of hardware
+ * @hw_addr: MAC address of hardware
+ * @ep_address: endpoint address table
+ * @link_stat: link status of hardware
+ * @description: device description
+ * @suffix: suffix for channel name
+ * @anchor_list_lock: locks list access
+ * @padding_active: indicates channel uses padding
+ * @is_channel_healthy: health status table of each channel
+ * @anchor_list: list of anchored items
+ * @io_mutex: synchronize I/O with disconnect
+ * @link_stat_timer: timer for link status reports
+ * @poll_work_obj: work for polling link status
+ */
+struct most_dev {
+	struct kobject *parent;
+	struct usb_device *usb_device;
+	struct most_interface iface;
+	struct most_channel_capability *cap;
+	struct most_channel_config *conf;
+	struct most_dci_obj *dci;
+	u8 hw_addr[6];
+	u8 *ep_address;
+	u16 link_stat;
+	char description[MAX_STRING_LEN];
+	char suffix[MAX_NUM_ENDPOINTS][MAX_SUFFIX_LEN];
+	spinlock_t anchor_list_lock[MAX_NUM_ENDPOINTS];
+	bool padding_active[MAX_NUM_ENDPOINTS];
+	bool is_channel_healthy[MAX_NUM_ENDPOINTS];
+	struct list_head *anchor_list;
+	struct mutex io_mutex;
+	struct timer_list link_stat_timer;
+	struct work_struct poll_work_obj;
+};
+
+#define to_mdev(d) container_of(d, struct most_dev, iface)
+#define to_mdev_from_work(w) container_of(w, struct most_dev, poll_work_obj)
+
+static struct workqueue_struct *schedule_usb_work;
+static void wq_clear_halt(struct work_struct *wq_obj);
+static void wq_netinfo(struct work_struct *wq_obj);
+
+/**
+ * drci_rd_reg - read a DCI register
+ * @dev: usb device
+ * @reg: register address
+ * @buf: buffer to store data
+ *
+ * This is reads data from INIC's direct register communication interface
+ */
+static inline int drci_rd_reg(struct usb_device *dev, u16 reg, u16 *buf)
+{
+	int retval;
+	u16 *dma_buf = kzalloc(sizeof(u16), GFP_KERNEL);
+	u8 req_type = USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE;
+
+	if (!dma_buf)
+		return -ENOMEM;
+
+	retval = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
+				 DRCI_READ_REQ, req_type,
+				 0x0000,
+				 reg, dma_buf, sizeof(u16), 5 * HZ);
+	*buf = le16_to_cpu(*dma_buf);
+	kfree(dma_buf);
+
+	return retval;
+}
+
+/**
+ * drci_wr_reg - write a DCI register
+ * @dev: usb device
+ * @reg: register address
+ * @data: data to write
+ *
+ * This is writes data to INIC's direct register communication interface
+ */
+static inline int drci_wr_reg(struct usb_device *dev, u16 reg, u16 data)
+{
+	return usb_control_msg(dev,
+			       usb_sndctrlpipe(dev, 0),
+			       DRCI_WRITE_REQ,
+			       USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+			       data,
+			       reg,
+			       NULL,
+			       0,
+			       5 * HZ);
+}
+
+/**
+ * free_anchored_buffers - free device's anchored items
+ * @mdev: the device
+ * @channel: channel ID
+ */
+static void free_anchored_buffers(struct most_dev *mdev, unsigned int channel)
+{
+	struct mbo *mbo;
+	struct buf_anchor *anchor, *tmp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&mdev->anchor_list_lock[channel], flags);
+	list_for_each_entry_safe(anchor, tmp, &mdev->anchor_list[channel],
+				 list) {
+		struct urb *urb = anchor->urb;
+
+		spin_unlock_irqrestore(&mdev->anchor_list_lock[channel], flags);
+		if (likely(urb)) {
+			mbo = urb->context;
+			if (!irqs_disabled()) {
+				usb_kill_urb(urb);
+			} else {
+				usb_unlink_urb(urb);
+				wait_for_completion(&anchor->urb_compl);
+			}
+			if ((mbo) && (mbo->complete)) {
+				mbo->status = MBO_E_CLOSE;
+				mbo->processed_length = 0;
+				mbo->complete(mbo);
+			}
+			usb_free_urb(urb);
+		}
+		spin_lock_irqsave(&mdev->anchor_list_lock[channel], flags);
+		list_del(&anchor->list);
+		kfree(anchor);
+	}
+	spin_unlock_irqrestore(&mdev->anchor_list_lock[channel], flags);
+}
+
+/**
+ * get_stream_frame_size - calculate frame size of current configuration
+ * @cfg: channel configuration
+ */
+static unsigned int get_stream_frame_size(struct most_channel_config *cfg)
+{
+	unsigned int frame_size = 0;
+	unsigned int sub_size = cfg->subbuffer_size;
+
+	if (!sub_size) {
+		pr_warn("Misconfig: Subbuffer size zero.\n");
+		return frame_size;
+	}
+	switch (cfg->data_type) {
+	case MOST_CH_ISOC_AVP:
+		frame_size = AV_PACKETS_PER_XACT * sub_size;
+		break;
+	case MOST_CH_SYNC:
+		if (cfg->packets_per_xact == 0) {
+			pr_warn("Misconfig: Packets per XACT zero\n");
+			frame_size = 0;
+		} else if (cfg->packets_per_xact == 0xFF) {
+			frame_size = (USB_MTU / sub_size) * sub_size;
+		} else {
+			frame_size = cfg->packets_per_xact * sub_size;
+		}
+		break;
+	default:
+		pr_warn("Query frame size of non-streaming channel\n");
+		break;
+	}
+	return frame_size;
+}
+
+/**
+ * hdm_poison_channel - mark buffers of this channel as invalid
+ * @iface: pointer to the interface
+ * @channel: channel ID
+ *
+ * This unlinks all URBs submitted to the HCD,
+ * calls the associated completion function of the core and removes
+ * them from the list.
+ *
+ * Returns 0 on success or error code otherwise.
+ */
+static int hdm_poison_channel(struct most_interface *iface, int channel)
+{
+	struct most_dev *mdev;
+
+	mdev = to_mdev(iface);
+	if (unlikely(!iface)) {
+		dev_warn(&mdev->usb_device->dev, "Poison: Bad interface.\n");
+		return -EIO;
+	}
+	if (unlikely((channel < 0) || (channel >= iface->num_channels))) {
+		dev_warn(&mdev->usb_device->dev, "Channel ID out of range.\n");
+		return -ECHRNG;
+	}
+
+	mdev->is_channel_healthy[channel] = false;
+
+	mutex_lock(&mdev->io_mutex);
+	free_anchored_buffers(mdev, channel);
+	if (mdev->padding_active[channel])
+		mdev->padding_active[channel] = false;
+
+	if (mdev->conf[channel].data_type == MOST_CH_ASYNC) {
+		del_timer_sync(&mdev->link_stat_timer);
+		cancel_work_sync(&mdev->poll_work_obj);
+	}
+	mutex_unlock(&mdev->io_mutex);
+	return 0;
+}
+
+/**
+ * hdm_add_padding - add padding bytes
+ * @mdev: most device
+ * @channel: channel ID
+ * @mbo: buffer object
+ *
+ * This inserts the INIC hardware specific padding bytes into a streaming
+ * channel's buffer
+ */
+static int hdm_add_padding(struct most_dev *mdev, int channel, struct mbo *mbo)
+{
+	struct most_channel_config *conf = &mdev->conf[channel];
+	unsigned int j, num_frames, frame_size;
+	u16 rd_addr, wr_addr;
+
+	frame_size = get_stream_frame_size(conf);
+	if (!frame_size)
+		return -EIO;
+	num_frames = mbo->buffer_length / frame_size;
+
+	if (num_frames < 1) {
+		dev_err(&mdev->usb_device->dev,
+			"Missed minimal transfer unit.\n");
+		return -EIO;
+	}
+
+	for (j = 1; j < num_frames; j++) {
+		wr_addr = (num_frames - j) * USB_MTU;
+		rd_addr = (num_frames - j) * frame_size;
+		memmove(mbo->virt_address + wr_addr,
+			mbo->virt_address + rd_addr,
+			frame_size);
+	}
+	mbo->buffer_length = num_frames * USB_MTU;
+	return 0;
+}
+
+/**
+ * hdm_remove_padding - remove padding bytes
+ * @mdev: most device
+ * @channel: channel ID
+ * @mbo: buffer object
+ *
+ * This takes the INIC hardware specific padding bytes off a streaming
+ * channel's buffer.
+ */
+static int hdm_remove_padding(struct most_dev *mdev, int channel,
+			      struct mbo *mbo)
+{
+	unsigned int j, num_frames, frame_size;
+	struct most_channel_config *const conf = &mdev->conf[channel];
+
+	frame_size = get_stream_frame_size(conf);
+	if (!frame_size)
+		return -EIO;
+	num_frames = mbo->processed_length / USB_MTU;
+
+	for (j = 1; j < num_frames; j++)
+		memmove(mbo->virt_address + frame_size * j,
+			mbo->virt_address + USB_MTU * j,
+			frame_size);
+
+	mbo->processed_length = frame_size * num_frames;
+	return 0;
+}
+
+/**
+ * hdm_write_completion - completion function for submitted Tx URBs
+ * @urb: the URB that has been completed
+ *
+ * This checks the status of the completed URB. In case the URB has been
+ * unlinked before, it is immediately freed. On any other error the MBO
+ * transfer flag is set. On success it frees allocated resources and calls
+ * the completion function.
+ *
+ * Context: interrupt!
+ */
+static void hdm_write_completion(struct urb *urb)
+{
+	struct mbo *mbo;
+	struct buf_anchor *anchor;
+	struct most_dev *mdev;
+	struct device *dev;
+	unsigned int channel;
+	unsigned long flags;
+
+	mbo = urb->context;
+	anchor = mbo->priv;
+	mdev = to_mdev(mbo->ifp);
+	channel = mbo->hdm_channel_id;
+	dev = &mdev->usb_device->dev;
+
+	if ((urb->status == -ENOENT) || (urb->status == -ECONNRESET) ||
+	    (!mdev->is_channel_healthy[channel])) {
+		complete(&anchor->urb_compl);
+		return;
+	}
+
+	if (unlikely(urb->status && !(urb->status == -ENOENT ||
+				      urb->status == -ECONNRESET ||
+				      urb->status == -ESHUTDOWN))) {
+		mbo->processed_length = 0;
+		switch (urb->status) {
+		case -EPIPE:
+			dev_warn(dev, "Broken OUT pipe detected\n");
+			most_stop_enqueue(&mdev->iface, channel);
+			mbo->status = MBO_E_INVAL;
+			usb_unlink_urb(urb);
+			INIT_WORK(&anchor->clear_work_obj, wq_clear_halt);
+			queue_work(schedule_usb_work, &anchor->clear_work_obj);
+			return;
+		case -ENODEV:
+		case -EPROTO:
+			mbo->status = MBO_E_CLOSE;
+			break;
+		default:
+			mbo->status = MBO_E_INVAL;
+			break;
+		}
+	} else {
+		mbo->status = MBO_SUCCESS;
+		mbo->processed_length = urb->actual_length;
+	}
+
+	spin_lock_irqsave(&mdev->anchor_list_lock[channel], flags);
+	list_del(&anchor->list);
+	spin_unlock_irqrestore(&mdev->anchor_list_lock[channel], flags);
+	kfree(anchor);
+
+	if (likely(mbo->complete))
+		mbo->complete(mbo);
+	usb_free_urb(urb);
+}
+
+/**
+ * hdm_read_completion - completion function for submitted Rx URBs
+ * @urb: the URB that has been completed
+ *
+ * This checks the status of the completed URB. In case the URB has been
+ * unlinked before it is immediately freed. On any other error the MBO transfer
+ * flag is set. On success it frees allocated resources, removes
+ * padding bytes -if necessary- and calls the completion function.
+ *
+ * Context: interrupt!
+ *
+ * **************************************************************************
+ *                   Error codes returned by in urb->status
+ *                   or in iso_frame_desc[n].status (for ISO)
+ * *************************************************************************
+ *
+ * USB device drivers may only test urb status values in completion handlers.
+ * This is because otherwise there would be a race between HCDs updating
+ * these values on one CPU, and device drivers testing them on another CPU.
+ *
+ * A transfer's actual_length may be positive even when an error has been
+ * reported.  That's because transfers often involve several packets, so that
+ * one or more packets could finish before an error stops further endpoint I/O.
+ *
+ * For isochronous URBs, the urb status value is non-zero only if the URB is
+ * unlinked, the device is removed, the host controller is disabled or the total
+ * transferred length is less than the requested length and the URB_SHORT_NOT_OK
+ * flag is set.  Completion handlers for isochronous URBs should only see
+ * urb->status set to zero, -ENOENT, -ECONNRESET, -ESHUTDOWN, or -EREMOTEIO.
+ * Individual frame descriptor status fields may report more status codes.
+ *
+ *
+ * 0			Transfer completed successfully
+ *
+ * -ENOENT		URB was synchronously unlinked by usb_unlink_urb
+ *
+ * -EINPROGRESS		URB still pending, no results yet
+ *			(That is, if drivers see this it's a bug.)
+ *
+ * -EPROTO (*, **)	a) bitstuff error
+ *			b) no response packet received within the
+ *			   prescribed bus turn-around time
+ *			c) unknown USB error
+ *
+ * -EILSEQ (*, **)	a) CRC mismatch
+ *			b) no response packet received within the
+ *			   prescribed bus turn-around time
+ *			c) unknown USB error
+ *
+ *			Note that often the controller hardware does not
+ *			distinguish among cases a), b), and c), so a
+ *			driver cannot tell whether there was a protocol
+ *			error, a failure to respond (often caused by
+ *			device disconnect), or some other fault.
+ *
+ * -ETIME (**)		No response packet received within the prescribed
+ *			bus turn-around time.  This error may instead be
+ *			reported as -EPROTO or -EILSEQ.
+ *
+ * -ETIMEDOUT		Synchronous USB message functions use this code
+ *			to indicate timeout expired before the transfer
+ *			completed, and no other error was reported by HC.
+ *
+ * -EPIPE (**)		Endpoint stalled.  For non-control endpoints,
+ *			reset this status with usb_clear_halt().
+ *
+ * -ECOMM		During an IN transfer, the host controller
+ *			received data from an endpoint faster than it
+ *			could be written to system memory
+ *
+ * -ENOSR		During an OUT transfer, the host controller
+ *			could not retrieve data from system memory fast
+ *			enough to keep up with the USB data rate
+ *
+ * -EOVERFLOW (*)	The amount of data returned by the endpoint was
+ *			greater than either the max packet size of the
+ *			endpoint or the remaining buffer size.  "Babble".
+ *
+ * -EREMOTEIO		The data read from the endpoint did not fill the
+ *			specified buffer, and URB_SHORT_NOT_OK was set in
+ *			urb->transfer_flags.
+ *
+ * -ENODEV		Device was removed.  Often preceded by a burst of
+ *			other errors, since the hub driver doesn't detect
+ *			device removal events immediately.
+ *
+ * -EXDEV		ISO transfer only partially completed
+ *			(only set in iso_frame_desc[n].status, not urb->status)
+ *
+ * -EINVAL		ISO madness, if this happens: Log off and go home
+ *
+ * -ECONNRESET		URB was asynchronously unlinked by usb_unlink_urb
+ *
+ * -ESHUTDOWN		The device or host controller has been disabled due
+ *			to some problem that could not be worked around,
+ *			such as a physical disconnect.
+ *
+ *
+ * (*) Error codes like -EPROTO, -EILSEQ and -EOVERFLOW normally indicate
+ * hardware problems such as bad devices (including firmware) or cables.
+ *
+ * (**) This is also one of several codes that different kinds of host
+ * controller use to indicate a transfer has failed because of device
+ * disconnect.  In the interval before the hub driver starts disconnect
+ * processing, devices may receive such fault reports for every request.
+ *
+ * See <https://www.kernel.org/doc/Documentation/usb/error-codes.txt>
+ */
+static void hdm_read_completion(struct urb *urb)
+{
+	struct mbo *mbo;
+	struct buf_anchor *anchor;
+	struct most_dev *mdev;
+	struct device *dev;
+	unsigned long flags;
+	unsigned int channel;
+
+	mbo = urb->context;
+	anchor = mbo->priv;
+	mdev = to_mdev(mbo->ifp);
+	channel = mbo->hdm_channel_id;
+	dev = &mdev->usb_device->dev;
+
+	if ((urb->status == -ENOENT) || (urb->status == -ECONNRESET) ||
+	    (!mdev->is_channel_healthy[channel])) {
+		complete(&anchor->urb_compl);
+		return;
+	}
+
+	if (unlikely(urb->status && !(urb->status == -ENOENT ||
+				      urb->status == -ECONNRESET ||
+				      urb->status == -ESHUTDOWN))) {
+		mbo->processed_length = 0;
+		switch (urb->status) {
+		case -EPIPE:
+			dev_warn(dev, "Broken IN pipe detected\n");
+			mbo->status = MBO_E_INVAL;
+			usb_unlink_urb(urb);
+			INIT_WORK(&anchor->clear_work_obj, wq_clear_halt);
+			queue_work(schedule_usb_work, &anchor->clear_work_obj);
+			return;
+		case -ENODEV:
+		case -EPROTO:
+			mbo->status = MBO_E_CLOSE;
+			break;
+		case -EOVERFLOW:
+			dev_warn(dev, "Babble on IN pipe detected\n");
+		default:
+			mbo->status = MBO_E_INVAL;
+			break;
+		}
+	} else {
+		mbo->processed_length = urb->actual_length;
+		if (!mdev->padding_active[channel]) {
+			mbo->status = MBO_SUCCESS;
+		} else {
+			if (hdm_remove_padding(mdev, channel, mbo)) {
+				mbo->processed_length = 0;
+				mbo->status = MBO_E_INVAL;
+			} else {
+				mbo->status = MBO_SUCCESS;
+			}
+		}
+	}
+	spin_lock_irqsave(&mdev->anchor_list_lock[channel], flags);
+	list_del(&anchor->list);
+	spin_unlock_irqrestore(&mdev->anchor_list_lock[channel], flags);
+	kfree(anchor);
+
+	if (likely(mbo->complete))
+		mbo->complete(mbo);
+	usb_free_urb(urb);
+}
+
+/**
+ * hdm_enqueue - receive a buffer to be used for data transfer
+ * @iface: interface to enqueue to
+ * @channel: ID of the channel
+ * @mbo: pointer to the buffer object
+ *
+ * This allocates a new URB and fills it according to the channel
+ * that is being used for transmission of data. Before the URB is
+ * submitted it is stored in the private anchor list.
+ *
+ * Returns 0 on success. On any error the URB is freed and a error code
+ * is returned.
+ *
+ * Context: Could in _some_ cases be interrupt!
+ */
+static int hdm_enqueue(struct most_interface *iface, int channel,
+		       struct mbo *mbo)
+{
+	struct most_dev *mdev;
+	struct buf_anchor *anchor;
+	struct most_channel_config *conf;
+	struct device *dev;
+	int retval = 0;
+	struct urb *urb;
+	unsigned long flags;
+	unsigned long length;
+	void *virt_address;
+
+	if (unlikely(!iface || !mbo))
+		return -EIO;
+	if (unlikely(iface->num_channels <= channel) || (channel < 0))
+		return -ECHRNG;
+
+	mdev = to_mdev(iface);
+	conf = &mdev->conf[channel];
+	dev = &mdev->usb_device->dev;
+
+	if (!mdev->usb_device)
+		return -ENODEV;
+
+	urb = usb_alloc_urb(NO_ISOCHRONOUS_URB, GFP_ATOMIC);
+	if (!urb) {
+		dev_err(dev, "Failed to allocate URB\n");
+		return -ENOMEM;
+	}
+
+	anchor = kzalloc(sizeof(*anchor), GFP_ATOMIC);
+	if (!anchor) {
+		retval = -ENOMEM;
+		goto _error;
+	}
+
+	anchor->urb = urb;
+	init_completion(&anchor->urb_compl);
+	mbo->priv = anchor;
+
+	spin_lock_irqsave(&mdev->anchor_list_lock[channel], flags);
+	list_add_tail(&anchor->list, &mdev->anchor_list[channel]);
+	spin_unlock_irqrestore(&mdev->anchor_list_lock[channel], flags);
+
+	if ((mdev->padding_active[channel]) &&
+	    (conf->direction & MOST_CH_TX))
+		if (hdm_add_padding(mdev, channel, mbo)) {
+			retval = -EIO;
+			goto _error_1;
+		}
+
+	urb->transfer_dma = mbo->bus_address;
+	virt_address = mbo->virt_address;
+	length = mbo->buffer_length;
+
+	if (conf->direction & MOST_CH_TX) {
+		usb_fill_bulk_urb(urb, mdev->usb_device,
+				  usb_sndbulkpipe(mdev->usb_device,
+						  mdev->ep_address[channel]),
+				  virt_address,
+				  length,
+				  hdm_write_completion,
+				  mbo);
+		if (conf->data_type != MOST_CH_ISOC_AVP)
+			urb->transfer_flags |= URB_ZERO_PACKET;
+	} else {
+		usb_fill_bulk_urb(urb, mdev->usb_device,
+				  usb_rcvbulkpipe(mdev->usb_device,
+						  mdev->ep_address[channel]),
+				  virt_address,
+				  length + conf->extra_len,
+				  hdm_read_completion,
+				  mbo);
+	}
+	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+	retval = usb_submit_urb(urb, GFP_KERNEL);
+	if (retval) {
+		dev_err(dev, "URB submit failed with error %d.\n", retval);
+		goto _error_1;
+	}
+	return 0;
+
+_error_1:
+	spin_lock_irqsave(&mdev->anchor_list_lock[channel], flags);
+	list_del(&anchor->list);
+	spin_unlock_irqrestore(&mdev->anchor_list_lock[channel], flags);
+	kfree(anchor);
+_error:
+	usb_free_urb(urb);
+	return retval;
+}
+
+/**
+ * hdm_configure_channel - receive channel configuration from core
+ * @iface: interface
+ * @channel: channel ID
+ * @conf: structure that holds the configuration information
+ */
+static int hdm_configure_channel(struct most_interface *iface, int channel,
+				 struct most_channel_config *conf)
+{
+	unsigned int num_frames;
+	unsigned int frame_size;
+	unsigned int temp_size;
+	unsigned int tail_space;
+	struct most_dev *mdev;
+	struct device *dev;
+
+	mdev = to_mdev(iface);
+	mdev->is_channel_healthy[channel] = true;
+	dev = &mdev->usb_device->dev;
+
+	if (unlikely(!iface || !conf)) {
+		dev_err(dev, "Bad interface or config pointer.\n");
+		return -EINVAL;
+	}
+	if (unlikely((channel < 0) || (channel >= iface->num_channels))) {
+		dev_err(dev, "Channel ID out of range.\n");
+		return -EINVAL;
+	}
+	if ((!conf->num_buffers) || (!conf->buffer_size)) {
+		dev_err(dev, "Misconfig: buffer size or #buffers zero.\n");
+		return -EINVAL;
+	}
+
+	if (!(conf->data_type == MOST_CH_SYNC) &&
+	    !((conf->data_type == MOST_CH_ISOC_AVP) &&
+	      (conf->packets_per_xact != 0xFF))) {
+		mdev->padding_active[channel] = false;
+		goto exit;
+	}
+
+	mdev->padding_active[channel] = true;
+	temp_size = conf->buffer_size;
+
+	frame_size = get_stream_frame_size(conf);
+	if ((frame_size == 0) || (frame_size > USB_MTU)) {
+		dev_warn(dev, "Misconfig: frame size wrong\n");
+		return -EINVAL;
+	}
+
+	if (conf->buffer_size % frame_size) {
+		u16 tmp_val;
+
+		tmp_val = conf->buffer_size / frame_size;
+		conf->buffer_size = tmp_val * frame_size;
+		dev_notice(dev,
+			   "Channel %d - rounding buffer size to %d bytes, channel config says %d bytes\n",
+			   channel,
+			   conf->buffer_size,
+			   temp_size);
+	}
+
+	num_frames = conf->buffer_size / frame_size;
+	tail_space = num_frames * (USB_MTU - frame_size);
+	temp_size += tail_space;
+
+	/* calculate extra length to comply w/ HW padding */
+	conf->extra_len = (CEILING(temp_size, USB_MTU) * USB_MTU)
+			  - conf->buffer_size;
+exit:
+	mdev->conf[channel] = *conf;
+	return 0;
+}
+
+/**
+ * hdm_update_netinfo - retrieve latest networking information
+ * @mdev: device interface
+ *
+ * This triggers the USB vendor requests to read the hardware address and
+ * the current link status of the attached device.
+ */
+static int hdm_update_netinfo(struct most_dev *mdev)
+{
+	struct usb_device *usb_device = mdev->usb_device;
+	struct device *dev = &usb_device->dev;
+	u16 hi, mi, lo, link;
+
+	if (!is_valid_ether_addr(mdev->hw_addr)) {
+		if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_HI, &hi) < 0) {
+			dev_err(dev, "Vendor request \"hw_addr_hi\" failed\n");
+			return -1;
+		}
+
+		if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_MI, &mi) < 0) {
+			dev_err(dev, "Vendor request \"hw_addr_mid\" failed\n");
+			return -1;
+		}
+
+		if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_LO, &lo) < 0) {
+			dev_err(dev, "Vendor request \"hw_addr_low\" failed\n");
+			return -1;
+		}
+
+		mutex_lock(&mdev->io_mutex);
+		mdev->hw_addr[0] = hi >> 8;
+		mdev->hw_addr[1] = hi;
+		mdev->hw_addr[2] = mi >> 8;
+		mdev->hw_addr[3] = mi;
+		mdev->hw_addr[4] = lo >> 8;
+		mdev->hw_addr[5] = lo;
+		mutex_unlock(&mdev->io_mutex);
+	}
+
+	if (drci_rd_reg(usb_device, DRCI_REG_NI_STATE, &link) < 0) {
+		dev_err(dev, "Vendor request \"link status\" failed\n");
+		return -1;
+	}
+
+	mutex_lock(&mdev->io_mutex);
+	mdev->link_stat = link;
+	mutex_unlock(&mdev->io_mutex);
+	return 0;
+}
+
+/**
+ * hdm_request_netinfo - request network information
+ * @iface: pointer to interface
+ * @channel: channel ID
+ *
+ * This is used as trigger to set up the link status timer that
+ * polls for the NI state of the INIC every 2 seconds.
+ *
+ */
+static void hdm_request_netinfo(struct most_interface *iface, int channel)
+{
+	struct most_dev *mdev;
+
+	BUG_ON(!iface);
+	mdev = to_mdev(iface);
+	mdev->link_stat_timer.expires = jiffies + HZ;
+	mod_timer(&mdev->link_stat_timer, mdev->link_stat_timer.expires);
+}
+
+/**
+ * link_stat_timer_handler - add work to link_stat work queue
+ * @data: pointer to USB device instance
+ *
+ * The handler runs in interrupt context. That's why we need to defer the
+ * tasks to a work queue.
+ */
+static void link_stat_timer_handler(unsigned long data)
+{
+	struct most_dev *mdev = (struct most_dev *)data;
+
+	queue_work(schedule_usb_work, &mdev->poll_work_obj);
+	mdev->link_stat_timer.expires = jiffies + (2 * HZ);
+	add_timer(&mdev->link_stat_timer);
+}
+
+/**
+ * wq_netinfo - work queue function
+ * @wq_obj: object that holds data for our deferred work to do
+ *
+ * This retrieves the network interface status of the USB INIC
+ * and compares it with the current status. If the status has
+ * changed, it updates the status of the core.
+ */
+static void wq_netinfo(struct work_struct *wq_obj)
+{
+	struct most_dev *mdev;
+	int i, prev_link_stat;
+	u8 prev_hw_addr[6];
+
+	mdev = to_mdev_from_work(wq_obj);
+	prev_link_stat = mdev->link_stat;
+
+	for (i = 0; i < 6; i++)
+		prev_hw_addr[i] = mdev->hw_addr[i];
+
+	if (hdm_update_netinfo(mdev) < 0)
+		return;
+	if ((prev_link_stat != mdev->link_stat) ||
+	    (prev_hw_addr[0] != mdev->hw_addr[0]) ||
+	    (prev_hw_addr[1] != mdev->hw_addr[1]) ||
+	    (prev_hw_addr[2] != mdev->hw_addr[2]) ||
+	    (prev_hw_addr[3] != mdev->hw_addr[3]) ||
+	    (prev_hw_addr[4] != mdev->hw_addr[4]) ||
+	    (prev_hw_addr[5] != mdev->hw_addr[5]))
+		most_deliver_netinfo(&mdev->iface, mdev->link_stat,
+				     &mdev->hw_addr[0]);
+}
+
+/**
+ * wq_clear_halt - work queue function
+ * @wq_obj: work_struct object to execute
+ *
+ * This sends a clear_halt to the given USB pipe.
+ */
+static void wq_clear_halt(struct work_struct *wq_obj)
+{
+	struct buf_anchor *anchor;
+	struct most_dev *mdev;
+	struct mbo *mbo;
+	struct urb *urb;
+	unsigned int channel;
+	unsigned long flags;
+
+	anchor = to_buf_anchor(wq_obj);
+	urb = anchor->urb;
+	mbo = urb->context;
+	mdev = to_mdev(mbo->ifp);
+	channel = mbo->hdm_channel_id;
+
+	if (usb_clear_halt(urb->dev, urb->pipe))
+		dev_warn(&mdev->usb_device->dev, "Failed to reset endpoint.\n");
+
+	usb_free_urb(urb);
+	spin_lock_irqsave(&mdev->anchor_list_lock[channel], flags);
+	list_del(&anchor->list);
+	spin_unlock_irqrestore(&mdev->anchor_list_lock[channel], flags);
+
+	if (likely(mbo->complete))
+		mbo->complete(mbo);
+	if (mdev->conf[channel].direction & MOST_CH_TX)
+		most_resume_enqueue(&mdev->iface, channel);
+
+	kfree(anchor);
+}
+
+/**
+ * hdm_usb_fops - file operation table for USB driver
+ */
+static const struct file_operations hdm_usb_fops = {
+	.owner = THIS_MODULE,
+};
+
+/**
+ * usb_device_id - ID table for HCD device probing
+ */
+static struct usb_device_id usbid[] = {
+	{ USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_BRDG), },
+	{ USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_INIC), },
+	{ } /* Terminating entry */
+};
+
+#define MOST_DCI_RO_ATTR(_name) \
+	struct most_dci_attribute most_dci_attr_##_name = \
+		__ATTR(_name, S_IRUGO, show_value, NULL)
+
+#define MOST_DCI_ATTR(_name) \
+	struct most_dci_attribute most_dci_attr_##_name = \
+		__ATTR(_name, S_IRUGO | S_IWUSR, show_value, store_value)
+
+/**
+ * struct most_dci_attribute - to access the attributes of a dci object
+ * @attr: attributes of a dci object
+ * @show: pointer to the show function
+ * @store: pointer to the store function
+ */
+struct most_dci_attribute {
+	struct attribute attr;
+	ssize_t (*show)(struct most_dci_obj *d,
+			struct most_dci_attribute *attr,
+			char *buf);
+	ssize_t (*store)(struct most_dci_obj *d,
+			 struct most_dci_attribute *attr,
+			 const char *buf,
+			 size_t count);
+};
+
+#define to_dci_attr(a) container_of(a, struct most_dci_attribute, attr)
+
+/**
+ * dci_attr_show - show function for dci object
+ * @kobj: pointer to kobject
+ * @attr: pointer to attribute struct
+ * @buf: buffer
+ */
+static ssize_t dci_attr_show(struct kobject *kobj, struct attribute *attr,
+			     char *buf)
+{
+	struct most_dci_attribute *dci_attr = to_dci_attr(attr);
+	struct most_dci_obj *dci_obj = to_dci_obj(kobj);
+
+	if (!dci_attr->show)
+		return -EIO;
+
+	return dci_attr->show(dci_obj, dci_attr, buf);
+}
+
+/**
+ * dci_attr_store - store function for dci object
+ * @kobj: pointer to kobject
+ * @attr: pointer to attribute struct
+ * @buf: buffer
+ * @len: length of buffer
+ */
+static ssize_t dci_attr_store(struct kobject *kobj,
+			      struct attribute *attr,
+			      const char *buf,
+			      size_t len)
+{
+	struct most_dci_attribute *dci_attr = to_dci_attr(attr);
+	struct most_dci_obj *dci_obj = to_dci_obj(kobj);
+
+	if (!dci_attr->store)
+		return -EIO;
+
+	return dci_attr->store(dci_obj, dci_attr, buf, len);
+}
+
+static const struct sysfs_ops most_dci_sysfs_ops = {
+	.show = dci_attr_show,
+	.store = dci_attr_store,
+};
+
+/**
+ * most_dci_release - release function for dci object
+ * @kobj: pointer to kobject
+ *
+ * This frees the memory allocated for the dci object
+ */
+static void most_dci_release(struct kobject *kobj)
+{
+	struct most_dci_obj *dci_obj = to_dci_obj(kobj);
+
+	kfree(dci_obj);
+}
+
+static ssize_t show_value(struct most_dci_obj *dci_obj,
+			  struct most_dci_attribute *attr, char *buf)
+{
+	u16 tmp_val;
+	u16 reg_addr;
+	int err;
+
+	if (!strcmp(attr->attr.name, "ni_state"))
+		reg_addr = DRCI_REG_NI_STATE;
+	else if (!strcmp(attr->attr.name, "packet_bandwidth"))
+		reg_addr = DRCI_REG_PACKET_BW;
+	else if (!strcmp(attr->attr.name, "node_address"))
+		reg_addr = DRCI_REG_NODE_ADDR;
+	else if (!strcmp(attr->attr.name, "node_position"))
+		reg_addr = DRCI_REG_NODE_POS;
+	else if (!strcmp(attr->attr.name, "mep_filter"))
+		reg_addr = DRCI_REG_MEP_FILTER;
+	else if (!strcmp(attr->attr.name, "mep_hash0"))
+		reg_addr = DRCI_REG_HASH_TBL0;
+	else if (!strcmp(attr->attr.name, "mep_hash1"))
+		reg_addr = DRCI_REG_HASH_TBL1;
+	else if (!strcmp(attr->attr.name, "mep_hash2"))
+		reg_addr = DRCI_REG_HASH_TBL2;
+	else if (!strcmp(attr->attr.name, "mep_hash3"))
+		reg_addr = DRCI_REG_HASH_TBL3;
+	else if (!strcmp(attr->attr.name, "mep_eui48_hi"))
+		reg_addr = DRCI_REG_HW_ADDR_HI;
+	else if (!strcmp(attr->attr.name, "mep_eui48_mi"))
+		reg_addr = DRCI_REG_HW_ADDR_MI;
+	else if (!strcmp(attr->attr.name, "mep_eui48_lo"))
+		reg_addr = DRCI_REG_HW_ADDR_LO;
+	else
+		return -EIO;
+
+	err = drci_rd_reg(dci_obj->usb_device, reg_addr, &tmp_val);
+	if (err < 0)
+		return err;
+
+	return snprintf(buf, PAGE_SIZE, "%04x\n", tmp_val);
+}
+
+static ssize_t store_value(struct most_dci_obj *dci_obj,
+			   struct most_dci_attribute *attr,
+			   const char *buf, size_t count)
+{
+	u16 val;
+	u16 reg_addr;
+	int err;
+
+	if (!strcmp(attr->attr.name, "mep_filter"))
+		reg_addr = DRCI_REG_MEP_FILTER;
+	else if (!strcmp(attr->attr.name, "mep_hash0"))
+		reg_addr = DRCI_REG_HASH_TBL0;
+	else if (!strcmp(attr->attr.name, "mep_hash1"))
+		reg_addr = DRCI_REG_HASH_TBL1;
+	else if (!strcmp(attr->attr.name, "mep_hash2"))
+		reg_addr = DRCI_REG_HASH_TBL2;
+	else if (!strcmp(attr->attr.name, "mep_hash3"))
+		reg_addr = DRCI_REG_HASH_TBL3;
+	else if (!strcmp(attr->attr.name, "mep_eui48_hi"))
+		reg_addr = DRCI_REG_HW_ADDR_HI;
+	else if (!strcmp(attr->attr.name, "mep_eui48_mi"))
+		reg_addr = DRCI_REG_HW_ADDR_MI;
+	else if (!strcmp(attr->attr.name, "mep_eui48_lo"))
+		reg_addr = DRCI_REG_HW_ADDR_LO;
+	else
+		return -EIO;
+
+	err = kstrtou16(buf, 16, &val);
+	if (err)
+		return err;
+
+	err = drci_wr_reg(dci_obj->usb_device, reg_addr, val);
+	if (err < 0)
+		return err;
+
+	return count;
+}
+
+static MOST_DCI_RO_ATTR(ni_state);
+static MOST_DCI_RO_ATTR(packet_bandwidth);
+static MOST_DCI_RO_ATTR(node_address);
+static MOST_DCI_RO_ATTR(node_position);
+static MOST_DCI_ATTR(mep_filter);
+static MOST_DCI_ATTR(mep_hash0);
+static MOST_DCI_ATTR(mep_hash1);
+static MOST_DCI_ATTR(mep_hash2);
+static MOST_DCI_ATTR(mep_hash3);
+static MOST_DCI_ATTR(mep_eui48_hi);
+static MOST_DCI_ATTR(mep_eui48_mi);
+static MOST_DCI_ATTR(mep_eui48_lo);
+
+/**
+ * most_dci_def_attrs - array of default attribute files of the dci object
+ */
+static struct attribute *most_dci_def_attrs[] = {
+	&most_dci_attr_ni_state.attr,
+	&most_dci_attr_packet_bandwidth.attr,
+	&most_dci_attr_node_address.attr,
+	&most_dci_attr_node_position.attr,
+	&most_dci_attr_mep_filter.attr,
+	&most_dci_attr_mep_hash0.attr,
+	&most_dci_attr_mep_hash1.attr,
+	&most_dci_attr_mep_hash2.attr,
+	&most_dci_attr_mep_hash3.attr,
+	&most_dci_attr_mep_eui48_hi.attr,
+	&most_dci_attr_mep_eui48_mi.attr,
+	&most_dci_attr_mep_eui48_lo.attr,
+	NULL,
+};
+
+/**
+ * DCI ktype
+ */
+static struct kobj_type most_dci_ktype = {
+	.sysfs_ops = &most_dci_sysfs_ops,
+	.release = most_dci_release,
+	.default_attrs = most_dci_def_attrs,
+};
+
+/**
+ * create_most_dci_obj - allocates a dci object
+ * @parent: parent kobject
+ *
+ * This creates a dci object and registers it with sysfs.
+ * Returns a pointer to the object or NULL when something went wrong.
+ */
+static struct
+most_dci_obj *create_most_dci_obj(struct kobject *parent)
+{
+	struct most_dci_obj *most_dci;
+	int retval;
+
+	most_dci = kzalloc(sizeof(*most_dci), GFP_KERNEL);
+	if (!most_dci)
+		return NULL;
+
+	retval = kobject_init_and_add(&most_dci->kobj, &most_dci_ktype, parent,
+				      "dci");
+	if (retval) {
+		kobject_put(&most_dci->kobj);
+		return NULL;
+	}
+	return most_dci;
+}
+
+/**
+ * destroy_most_dci_obj - DCI object release function
+ * @p: pointer to dci object
+ */
+static void destroy_most_dci_obj(struct most_dci_obj *p)
+{
+	kobject_put(&p->kobj);
+}
+
+/**
+ * hdm_probe - probe function of USB device driver
+ * @interface: Interface of the attached USB device
+ * @id: Pointer to the USB ID table.
+ *
+ * This allocates and initializes the device instance, adds the new
+ * entry to the internal list, scans the USB descriptors and registers
+ * the interface with the core.
+ * Additionally, the DCI objects are created and the hardware is sync'd.
+ *
+ * Return 0 on success. In case of an error a negative number is returned.
+ */
+static int
+hdm_probe(struct usb_interface *interface, const struct usb_device_id *id)
+{
+	unsigned int i;
+	unsigned int num_endpoints;
+	struct most_channel_capability *tmp_cap;
+	struct most_dev *mdev;
+	struct usb_device *usb_dev;
+	struct device *dev;
+	struct usb_host_interface *usb_iface_desc;
+	struct usb_endpoint_descriptor *ep_desc;
+	int ret = 0;
+	int err;
+
+	usb_iface_desc = interface->cur_altsetting;
+	usb_dev = interface_to_usbdev(interface);
+	dev = &usb_dev->dev;
+	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
+	if (!mdev)
+		goto exit_ENOMEM;
+
+	usb_set_intfdata(interface, mdev);
+	num_endpoints = usb_iface_desc->desc.bNumEndpoints;
+	mutex_init(&mdev->io_mutex);
+	INIT_WORK(&mdev->poll_work_obj, wq_netinfo);
+	setup_timer(&mdev->link_stat_timer, link_stat_timer_handler,
+		    (unsigned long)mdev);
+
+	mdev->usb_device = usb_dev;
+	mdev->link_stat_timer.expires = jiffies + (2 * HZ);
+
+	mdev->iface.mod = hdm_usb_fops.owner;
+	mdev->iface.interface = ITYPE_USB;
+	mdev->iface.configure = hdm_configure_channel;
+	mdev->iface.request_netinfo = hdm_request_netinfo;
+	mdev->iface.enqueue = hdm_enqueue;
+	mdev->iface.poison_channel = hdm_poison_channel;
+	mdev->iface.description = mdev->description;
+	mdev->iface.num_channels = num_endpoints;
+
+	snprintf(mdev->description, sizeof(mdev->description),
+		 "usb_device %d-%s:%d.%d",
+		 usb_dev->bus->busnum,
+		 usb_dev->devpath,
+		 usb_dev->config->desc.bConfigurationValue,
+		 usb_iface_desc->desc.bInterfaceNumber);
+
+	mdev->conf = kcalloc(num_endpoints, sizeof(*mdev->conf), GFP_KERNEL);
+	if (!mdev->conf)
+		goto exit_free;
+
+	mdev->cap = kcalloc(num_endpoints, sizeof(*mdev->cap), GFP_KERNEL);
+	if (!mdev->cap)
+		goto exit_free1;
+
+	mdev->iface.channel_vector = mdev->cap;
+	mdev->iface.priv = NULL;
+
+	mdev->ep_address =
+		kcalloc(num_endpoints, sizeof(*mdev->ep_address), GFP_KERNEL);
+	if (!mdev->ep_address)
+		goto exit_free2;
+
+	mdev->anchor_list =
+		kcalloc(num_endpoints, sizeof(*mdev->anchor_list), GFP_KERNEL);
+	if (!mdev->anchor_list)
+		goto exit_free3;
+
+	tmp_cap = mdev->cap;
+	for (i = 0; i < num_endpoints; i++) {
+		ep_desc = &usb_iface_desc->endpoint[i].desc;
+		mdev->ep_address[i] = ep_desc->bEndpointAddress;
+		mdev->padding_active[i] = false;
+		mdev->is_channel_healthy[i] = true;
+
+		snprintf(&mdev->suffix[i][0], MAX_SUFFIX_LEN, "ep%02x",
+			 mdev->ep_address[i]);
+
+		tmp_cap->name_suffix = &mdev->suffix[i][0];
+		tmp_cap->buffer_size_packet = MAX_BUF_SIZE;
+		tmp_cap->buffer_size_streaming = MAX_BUF_SIZE;
+		tmp_cap->num_buffers_packet = BUF_CHAIN_SIZE;
+		tmp_cap->num_buffers_streaming = BUF_CHAIN_SIZE;
+		tmp_cap->data_type = MOST_CH_CONTROL | MOST_CH_ASYNC |
+				     MOST_CH_ISOC_AVP | MOST_CH_SYNC;
+		if (ep_desc->bEndpointAddress & USB_DIR_IN)
+			tmp_cap->direction = MOST_CH_RX;
+		else
+			tmp_cap->direction = MOST_CH_TX;
+		tmp_cap++;
+		INIT_LIST_HEAD(&mdev->anchor_list[i]);
+		spin_lock_init(&mdev->anchor_list_lock[i]);
+		err = drci_wr_reg(usb_dev,
+				  DRCI_REG_BASE + DRCI_COMMAND +
+				  ep_desc->bEndpointAddress * 16,
+				  1);
+		if (err < 0)
+			pr_warn("DCI Sync for EP %02x failed",
+				ep_desc->bEndpointAddress);
+	}
+	dev_notice(dev, "claimed gadget: Vendor=%4.4x ProdID=%4.4x Bus=%02x Device=%02x\n",
+		   le16_to_cpu(usb_dev->descriptor.idVendor),
+		   le16_to_cpu(usb_dev->descriptor.idProduct),
+		   usb_dev->bus->busnum,
+		   usb_dev->devnum);
+
+	dev_notice(dev, "device path: /sys/bus/usb/devices/%d-%s:%d.%d\n",
+		   usb_dev->bus->busnum,
+		   usb_dev->devpath,
+		   usb_dev->config->desc.bConfigurationValue,
+		   usb_iface_desc->desc.bInterfaceNumber);
+
+	mdev->parent = most_register_interface(&mdev->iface);
+	if (IS_ERR(mdev->parent)) {
+		ret = PTR_ERR(mdev->parent);
+		goto exit_free4;
+	}
+
+	mutex_lock(&mdev->io_mutex);
+	if (le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_INIC) {
+		/* this increments the reference count of the instance
+		 * object of the core
+		 */
+		mdev->dci = create_most_dci_obj(mdev->parent);
+		if (!mdev->dci) {
+			mutex_unlock(&mdev->io_mutex);
+			most_deregister_interface(&mdev->iface);
+			ret = -ENOMEM;
+			goto exit_free4;
+		}
+
+		kobject_uevent(&mdev->dci->kobj, KOBJ_ADD);
+		mdev->dci->usb_device = mdev->usb_device;
+	}
+	mutex_unlock(&mdev->io_mutex);
+	return 0;
+
+exit_free4:
+	kfree(mdev->anchor_list);
+exit_free3:
+	kfree(mdev->ep_address);
+exit_free2:
+	kfree(mdev->cap);
+exit_free1:
+	kfree(mdev->conf);
+exit_free:
+	kfree(mdev);
+exit_ENOMEM:
+	if (ret == 0 || ret == -ENOMEM) {
+		ret = -ENOMEM;
+		dev_err(dev, "out of memory\n");
+	}
+	return ret;
+}
+
+/**
+ * hdm_disconnect - disconnect function of USB device driver
+ * @interface: Interface of the attached USB device
+ *
+ * This deregisters the interface with the core, removes the kernel timer
+ * and frees resources.
+ *
+ * Context: hub kernel thread
+ */
+static void hdm_disconnect(struct usb_interface *interface)
+{
+	struct most_dev *mdev;
+
+	mdev = usb_get_intfdata(interface);
+	mutex_lock(&mdev->io_mutex);
+	usb_set_intfdata(interface, NULL);
+	mdev->usb_device = NULL;
+	mutex_unlock(&mdev->io_mutex);
+
+	del_timer_sync(&mdev->link_stat_timer);
+	cancel_work_sync(&mdev->poll_work_obj);
+
+	destroy_most_dci_obj(mdev->dci);
+	most_deregister_interface(&mdev->iface);
+
+	kfree(mdev->anchor_list);
+	kfree(mdev->cap);
+	kfree(mdev->conf);
+	kfree(mdev->ep_address);
+	kfree(mdev);
+}
+
+static struct usb_driver hdm_usb = {
+	.name = "hdm_usb",
+	.id_table = usbid,
+	.probe = hdm_probe,
+	.disconnect = hdm_disconnect,
+};
+
+static int __init hdm_usb_init(void)
+{
+	pr_info("hdm_usb_init()\n");
+	if (usb_register(&hdm_usb)) {
+		pr_err("could not register hdm_usb driver\n");
+		return -EIO;
+	}
+	schedule_usb_work = create_workqueue("hdmu_work");
+	if (!schedule_usb_work) {
+		pr_err("could not create workqueue\n");
+		usb_deregister(&hdm_usb);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+static void __exit hdm_usb_exit(void)
+{
+	pr_info("hdm_usb_exit()\n");
+	destroy_workqueue(schedule_usb_work);
+	usb_deregister(&hdm_usb);
+}
+
+module_init(hdm_usb_init);
+module_exit(hdm_usb_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Christian Gromm <christian.gromm@microchip.com>");
+MODULE_DESCRIPTION("HDM_4_USB");