Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 1191 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/sur40.c b/drivers/input/touchscreen/sur40.c
new file mode 100644
index 000000000..09d8c5f8d
--- /dev/null
+++ b/drivers/input/touchscreen/sur40.c
@@ -0,0 +1,1191 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Surface2.0/SUR40/PixelSense input driver
+ *
+ * Copyright (c) 2014 by Florian 'floe' Echtler <floe@butterbrot.org>
+ *
+ * Derived from the USB Skeleton driver 1.1,
+ * Copyright (c) 2003 Greg Kroah-Hartman (greg@kroah.com)
+ *
+ * and from the Apple USB BCM5974 multitouch driver,
+ * Copyright (c) 2008 Henrik Rydberg (rydberg@euromail.se)
+ *
+ * and from the generic hid-multitouch driver,
+ * Copyright (c) 2010-2012 Stephane Chatty <chatty@enac.fr>
+ *
+ * and from the v4l2-pci-skeleton driver,
+ * Copyright (c) Copyright 2014 Cisco Systems, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/completion.h>
+#include <linux/uaccess.h>
+#include <linux/usb.h>
+#include <linux/printk.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/usb/input.h>
+#include <linux/videodev2.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-dev.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-ctrls.h>
+#include <media/videobuf2-v4l2.h>
+#include <media/videobuf2-dma-sg.h>
+
+/* read 512 bytes from endpoint 0x86 -> get header + blobs */
+struct sur40_header {
+
+	__le16 type;       /* always 0x0001 */
+	__le16 count;      /* count of blobs (if 0: continue prev. packet) */
+
+	__le32 packet_id;  /* unique ID for all packets in one frame */
+
+	__le32 timestamp;  /* milliseconds (inc. by 16 or 17 each frame) */
+	__le32 unknown;    /* "epoch?" always 02/03 00 00 00 */
+
+} __packed;
+
+struct sur40_blob {
+
+	__le16 blob_id;
+
+	u8 action;         /* 0x02 = enter/exit, 0x03 = update (?) */
+	u8 type;           /* bitmask (0x01 blob,  0x02 touch, 0x04 tag) */
+
+	__le16 bb_pos_x;   /* upper left corner of bounding box */
+	__le16 bb_pos_y;
+
+	__le16 bb_size_x;  /* size of bounding box */
+	__le16 bb_size_y;
+
+	__le16 pos_x;      /* finger tip position */
+	__le16 pos_y;
+
+	__le16 ctr_x;      /* centroid position */
+	__le16 ctr_y;
+
+	__le16 axis_x;     /* somehow related to major/minor axis, mostly: */
+	__le16 axis_y;     /* axis_x == bb_size_y && axis_y == bb_size_x */
+
+	__le32 angle;      /* orientation in radians relative to x axis -
+	                      actually an IEEE754 float, don't use in kernel */
+
+	__le32 area;       /* size in pixels/pressure (?) */
+
+	u8 padding[24];
+
+	__le32 tag_id;     /* valid when type == 0x04 (SUR40_TAG) */
+	__le32 unknown;
+
+} __packed;
+
+/* combined header/blob data */
+struct sur40_data {
+	struct sur40_header header;
+	struct sur40_blob   blobs[];
+} __packed;
+
+/* read 512 bytes from endpoint 0x82 -> get header below
+ * continue reading 16k blocks until header.size bytes read */
+struct sur40_image_header {
+	__le32 magic;     /* "SUBF" */
+	__le32 packet_id;
+	__le32 size;      /* always 0x0007e900 = 960x540 */
+	__le32 timestamp; /* milliseconds (increases by 16 or 17 each frame) */
+	__le32 unknown;   /* "epoch?" always 02/03 00 00 00 */
+} __packed;
+
+/* version information */
+#define DRIVER_SHORT   "sur40"
+#define DRIVER_LONG    "Samsung SUR40"
+#define DRIVER_AUTHOR  "Florian 'floe' Echtler <floe@butterbrot.org>"
+#define DRIVER_DESC    "Surface2.0/SUR40/PixelSense input driver"
+
+/* vendor and device IDs */
+#define ID_MICROSOFT 0x045e
+#define ID_SUR40     0x0775
+
+/* sensor resolution */
+#define SENSOR_RES_X 1920
+#define SENSOR_RES_Y 1080
+
+/* touch data endpoint */
+#define TOUCH_ENDPOINT 0x86
+
+/* video data endpoint */
+#define VIDEO_ENDPOINT 0x82
+
+/* video header fields */
+#define VIDEO_HEADER_MAGIC 0x46425553
+#define VIDEO_PACKET_SIZE  16384
+
+/* polling interval (ms) */
+#define POLL_INTERVAL 1
+
+/* maximum number of contacts */
+#define MAX_CONTACTS 52
+
+/* control commands */
+#define SUR40_GET_VERSION 0xb0 /* 12 bytes string    */
+#define SUR40_ACCEL_CAPS  0xb3 /*  5 bytes           */
+#define SUR40_SENSOR_CAPS 0xc1 /* 24 bytes           */
+
+#define SUR40_POKE        0xc5 /* poke register byte */
+#define SUR40_PEEK        0xc4 /* 48 bytes registers */
+
+#define SUR40_GET_STATE   0xc5 /*  4 bytes state (?) */
+#define SUR40_GET_SENSORS 0xb1 /*  8 bytes sensors   */
+
+#define SUR40_BLOB	0x01
+#define SUR40_TOUCH	0x02
+#define SUR40_TAG	0x04
+
+/* video controls */
+#define SUR40_BRIGHTNESS_MAX 0xff
+#define SUR40_BRIGHTNESS_MIN 0x00
+#define SUR40_BRIGHTNESS_DEF 0xff
+
+#define SUR40_CONTRAST_MAX 0x0f
+#define SUR40_CONTRAST_MIN 0x00
+#define SUR40_CONTRAST_DEF 0x0a
+
+#define SUR40_GAIN_MAX 0x09
+#define SUR40_GAIN_MIN 0x00
+#define SUR40_GAIN_DEF 0x08
+
+#define SUR40_BACKLIGHT_MAX 0x01
+#define SUR40_BACKLIGHT_MIN 0x00
+#define SUR40_BACKLIGHT_DEF 0x01
+
+#define sur40_str(s) #s
+#define SUR40_PARAM_RANGE(lo, hi) " (range " sur40_str(lo) "-" sur40_str(hi) ")"
+
+/* module parameters */
+static uint brightness = SUR40_BRIGHTNESS_DEF;
+module_param(brightness, uint, 0644);
+MODULE_PARM_DESC(brightness, "set initial brightness"
+	SUR40_PARAM_RANGE(SUR40_BRIGHTNESS_MIN, SUR40_BRIGHTNESS_MAX));
+static uint contrast = SUR40_CONTRAST_DEF;
+module_param(contrast, uint, 0644);
+MODULE_PARM_DESC(contrast, "set initial contrast"
+	SUR40_PARAM_RANGE(SUR40_CONTRAST_MIN, SUR40_CONTRAST_MAX));
+static uint gain = SUR40_GAIN_DEF;
+module_param(gain, uint, 0644);
+MODULE_PARM_DESC(gain, "set initial gain"
+	SUR40_PARAM_RANGE(SUR40_GAIN_MIN, SUR40_GAIN_MAX));
+
+static const struct v4l2_pix_format sur40_pix_format[] = {
+	{
+		.pixelformat = V4L2_TCH_FMT_TU08,
+		.width  = SENSOR_RES_X / 2,
+		.height = SENSOR_RES_Y / 2,
+		.field = V4L2_FIELD_NONE,
+		.colorspace = V4L2_COLORSPACE_RAW,
+		.bytesperline = SENSOR_RES_X / 2,
+		.sizeimage = (SENSOR_RES_X/2) * (SENSOR_RES_Y/2),
+	},
+	{
+		.pixelformat = V4L2_PIX_FMT_GREY,
+		.width  = SENSOR_RES_X / 2,
+		.height = SENSOR_RES_Y / 2,
+		.field = V4L2_FIELD_NONE,
+		.colorspace = V4L2_COLORSPACE_RAW,
+		.bytesperline = SENSOR_RES_X / 2,
+		.sizeimage = (SENSOR_RES_X/2) * (SENSOR_RES_Y/2),
+	}
+};
+
+/* master device state */
+struct sur40_state {
+
+	struct usb_device *usbdev;
+	struct device *dev;
+	struct input_dev *input;
+
+	struct v4l2_device v4l2;
+	struct video_device vdev;
+	struct mutex lock;
+	struct v4l2_pix_format pix_fmt;
+	struct v4l2_ctrl_handler hdl;
+
+	struct vb2_queue queue;
+	struct list_head buf_list;
+	spinlock_t qlock;
+	int sequence;
+
+	struct sur40_data *bulk_in_buffer;
+	size_t bulk_in_size;
+	u8 bulk_in_epaddr;
+	u8 vsvideo;
+
+	char phys[64];
+};
+
+struct sur40_buffer {
+	struct vb2_v4l2_buffer vb;
+	struct list_head list;
+};
+
+/* forward declarations */
+static const struct video_device sur40_video_device;
+static const struct vb2_queue sur40_queue;
+static void sur40_process_video(struct sur40_state *sur40);
+static int sur40_s_ctrl(struct v4l2_ctrl *ctrl);
+
+static const struct v4l2_ctrl_ops sur40_ctrl_ops = {
+	.s_ctrl = sur40_s_ctrl,
+};
+
+/*
+ * Note: an earlier, non-public version of this driver used USB_RECIP_ENDPOINT
+ * here by mistake which is very likely to have corrupted the firmware EEPROM
+ * on two separate SUR40 devices. Thanks to Alan Stern who spotted this bug.
+ * Should you ever run into a similar problem, the background story to this
+ * incident and instructions on how to fix the corrupted EEPROM are available
+ * at https://floe.butterbrot.org/matrix/hacking/surface/brick.html
+*/
+
+/* command wrapper */
+static int sur40_command(struct sur40_state *dev,
+			 u8 command, u16 index, void *buffer, u16 size)
+{
+	return usb_control_msg(dev->usbdev, usb_rcvctrlpipe(dev->usbdev, 0),
+			       command,
+			       USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
+			       0x00, index, buffer, size, 1000);
+}
+
+/* poke a byte in the panel register space */
+static int sur40_poke(struct sur40_state *dev, u8 offset, u8 value)
+{
+	int result;
+	u8 index = 0x96; // 0xae for permanent write
+
+	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
+		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
+		0x32, index, NULL, 0, 1000);
+	if (result < 0)
+		goto error;
+	msleep(5);
+
+	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
+		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
+		0x72, offset, NULL, 0, 1000);
+	if (result < 0)
+		goto error;
+	msleep(5);
+
+	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
+		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
+		0xb2, value, NULL, 0, 1000);
+	if (result < 0)
+		goto error;
+	msleep(5);
+
+error:
+	return result;
+}
+
+static int sur40_set_preprocessor(struct sur40_state *dev, u8 value)
+{
+	u8 setting_07[2] = { 0x01, 0x00 };
+	u8 setting_17[2] = { 0x85, 0x80 };
+	int result;
+
+	if (value > 1)
+		return -ERANGE;
+
+	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
+		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
+		0x07, setting_07[value], NULL, 0, 1000);
+	if (result < 0)
+		goto error;
+	msleep(5);
+
+	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
+		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
+		0x17, setting_17[value], NULL, 0, 1000);
+	if (result < 0)
+		goto error;
+	msleep(5);
+
+error:
+	return result;
+}
+
+static void sur40_set_vsvideo(struct sur40_state *handle, u8 value)
+{
+	int i;
+
+	for (i = 0; i < 4; i++)
+		sur40_poke(handle, 0x1c+i, value);
+	handle->vsvideo = value;
+}
+
+static void sur40_set_irlevel(struct sur40_state *handle, u8 value)
+{
+	int i;
+
+	for (i = 0; i < 8; i++)
+		sur40_poke(handle, 0x08+(2*i), value);
+}
+
+/* Initialization routine, called from sur40_open */
+static int sur40_init(struct sur40_state *dev)
+{
+	int result;
+	u8 *buffer;
+
+	buffer = kmalloc(24, GFP_KERNEL);
+	if (!buffer) {
+		result = -ENOMEM;
+		goto error;
+	}
+
+	/* stupidly replay the original MS driver init sequence */
+	result = sur40_command(dev, SUR40_GET_VERSION, 0x00, buffer, 12);
+	if (result < 0)
+		goto error;
+
+	result = sur40_command(dev, SUR40_GET_VERSION, 0x01, buffer, 12);
+	if (result < 0)
+		goto error;
+
+	result = sur40_command(dev, SUR40_GET_VERSION, 0x02, buffer, 12);
+	if (result < 0)
+		goto error;
+
+	result = sur40_command(dev, SUR40_SENSOR_CAPS, 0x00, buffer, 24);
+	if (result < 0)
+		goto error;
+
+	result = sur40_command(dev, SUR40_ACCEL_CAPS, 0x00, buffer, 5);
+	if (result < 0)
+		goto error;
+
+	result = sur40_command(dev, SUR40_GET_VERSION, 0x03, buffer, 12);
+	if (result < 0)
+		goto error;
+
+	result = 0;
+
+	/*
+	 * Discard the result buffer - no known data inside except
+	 * some version strings, maybe extract these sometime...
+	 */
+error:
+	kfree(buffer);
+	return result;
+}
+
+/*
+ * Callback routines from input_dev
+ */
+
+/* Enable the device, polling will now start. */
+static int sur40_open(struct input_dev *input)
+{
+	struct sur40_state *sur40 = input_get_drvdata(input);
+
+	dev_dbg(sur40->dev, "open\n");
+	return sur40_init(sur40);
+}
+
+/* Disable device, polling has stopped. */
+static void sur40_close(struct input_dev *input)
+{
+	struct sur40_state *sur40 = input_get_drvdata(input);
+
+	dev_dbg(sur40->dev, "close\n");
+	/*
+	 * There is no known way to stop the device, so we simply
+	 * stop polling.
+	 */
+}
+
+/*
+ * This function is called when a whole contact has been processed,
+ * so that it can assign it to a slot and store the data there.
+ */
+static void sur40_report_blob(struct sur40_blob *blob, struct input_dev *input)
+{
+	int wide, major, minor;
+	int bb_size_x, bb_size_y, pos_x, pos_y, ctr_x, ctr_y, slotnum;
+
+	if (blob->type != SUR40_TOUCH)
+		return;
+
+	slotnum = input_mt_get_slot_by_key(input, le16_to_cpu(blob->blob_id));
+	if (slotnum < 0 || slotnum >= MAX_CONTACTS)
+		return;
+
+	bb_size_x = le16_to_cpu(blob->bb_size_x);
+	bb_size_y = le16_to_cpu(blob->bb_size_y);
+
+	pos_x = le16_to_cpu(blob->pos_x);
+	pos_y = le16_to_cpu(blob->pos_y);
+
+	ctr_x = le16_to_cpu(blob->ctr_x);
+	ctr_y = le16_to_cpu(blob->ctr_y);
+
+	input_mt_slot(input, slotnum);
+	input_mt_report_slot_state(input, MT_TOOL_FINGER, 1);
+	wide = (bb_size_x > bb_size_y);
+	major = max(bb_size_x, bb_size_y);
+	minor = min(bb_size_x, bb_size_y);
+
+	input_report_abs(input, ABS_MT_POSITION_X, pos_x);
+	input_report_abs(input, ABS_MT_POSITION_Y, pos_y);
+	input_report_abs(input, ABS_MT_TOOL_X, ctr_x);
+	input_report_abs(input, ABS_MT_TOOL_Y, ctr_y);
+
+	/* TODO: use a better orientation measure */
+	input_report_abs(input, ABS_MT_ORIENTATION, wide);
+	input_report_abs(input, ABS_MT_TOUCH_MAJOR, major);
+	input_report_abs(input, ABS_MT_TOUCH_MINOR, minor);
+}
+
+/* core function: poll for new input data */
+static void sur40_poll(struct input_dev *input)
+{
+	struct sur40_state *sur40 = input_get_drvdata(input);
+	int result, bulk_read, need_blobs, packet_blobs, i;
+	struct sur40_header *header = &sur40->bulk_in_buffer->header;
+	struct sur40_blob *inblob = &sur40->bulk_in_buffer->blobs[0];
+
+	dev_dbg(sur40->dev, "poll\n");
+
+	need_blobs = -1;
+
+	do {
+
+		/* perform a blocking bulk read to get data from the device */
+		result = usb_bulk_msg(sur40->usbdev,
+			usb_rcvbulkpipe(sur40->usbdev, sur40->bulk_in_epaddr),
+			sur40->bulk_in_buffer, sur40->bulk_in_size,
+			&bulk_read, 1000);
+
+		dev_dbg(sur40->dev, "received %d bytes\n", bulk_read);
+
+		if (result < 0) {
+			dev_err(sur40->dev, "error in usb_bulk_read\n");
+			return;
+		}
+
+		result = bulk_read - sizeof(struct sur40_header);
+
+		if (result % sizeof(struct sur40_blob) != 0) {
+			dev_err(sur40->dev, "transfer size mismatch\n");
+			return;
+		}
+
+		/* first packet? */
+		if (need_blobs == -1) {
+			need_blobs = le16_to_cpu(header->count);
+			dev_dbg(sur40->dev, "need %d blobs\n", need_blobs);
+			/* packet_id = le32_to_cpu(header->packet_id); */
+		}
+
+		/*
+		 * Sanity check. when video data is also being retrieved, the
+		 * packet ID will usually increase in the middle of a series
+		 * instead of at the end. However, the data is still consistent,
+		 * so the packet ID is probably just valid for the first packet
+		 * in a series.
+
+		if (packet_id != le32_to_cpu(header->packet_id))
+			dev_dbg(sur40->dev, "packet ID mismatch\n");
+		 */
+
+		packet_blobs = result / sizeof(struct sur40_blob);
+		dev_dbg(sur40->dev, "received %d blobs\n", packet_blobs);
+
+		/* packets always contain at least 4 blobs, even if empty */
+		if (packet_blobs > need_blobs)
+			packet_blobs = need_blobs;
+
+		for (i = 0; i < packet_blobs; i++) {
+			need_blobs--;
+			dev_dbg(sur40->dev, "processing blob\n");
+			sur40_report_blob(&(inblob[i]), input);
+		}
+
+	} while (need_blobs > 0);
+
+	input_mt_sync_frame(input);
+	input_sync(input);
+
+	sur40_process_video(sur40);
+}
+
+/* deal with video data */
+static void sur40_process_video(struct sur40_state *sur40)
+{
+
+	struct sur40_image_header *img = (void *)(sur40->bulk_in_buffer);
+	struct sur40_buffer *new_buf;
+	struct usb_sg_request sgr;
+	struct sg_table *sgt;
+	int result, bulk_read;
+
+	if (!vb2_start_streaming_called(&sur40->queue))
+		return;
+
+	/* get a new buffer from the list */
+	scoped_guard(spinlock, &sur40->qlock) {
+		if (list_empty(&sur40->buf_list)) {
+			dev_dbg(sur40->dev, "buffer queue empty\n");
+			return;
+		}
+		new_buf = list_first_entry(&sur40->buf_list,
+					   struct sur40_buffer, list);
+		list_del(&new_buf->list);
+	}
+
+	dev_dbg(sur40->dev, "buffer acquired\n");
+
+	/* retrieve data via bulk read */
+	result = usb_bulk_msg(sur40->usbdev,
+			usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT),
+			sur40->bulk_in_buffer, sur40->bulk_in_size,
+			&bulk_read, 1000);
+
+	if (result < 0) {
+		dev_err(sur40->dev, "error in usb_bulk_read\n");
+		goto err_poll;
+	}
+
+	if (bulk_read != sizeof(struct sur40_image_header)) {
+		dev_err(sur40->dev, "received %d bytes (%zd expected)\n",
+			bulk_read, sizeof(struct sur40_image_header));
+		goto err_poll;
+	}
+
+	if (le32_to_cpu(img->magic) != VIDEO_HEADER_MAGIC) {
+		dev_err(sur40->dev, "image magic mismatch\n");
+		goto err_poll;
+	}
+
+	if (le32_to_cpu(img->size) != sur40->pix_fmt.sizeimage) {
+		dev_err(sur40->dev, "image size mismatch\n");
+		goto err_poll;
+	}
+
+	dev_dbg(sur40->dev, "header acquired\n");
+
+	sgt = vb2_dma_sg_plane_desc(&new_buf->vb.vb2_buf, 0);
+
+	result = usb_sg_init(&sgr, sur40->usbdev,
+		usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT), 0,
+		sgt->sgl, sgt->nents, sur40->pix_fmt.sizeimage, 0);
+	if (result < 0) {
+		dev_err(sur40->dev, "error %d in usb_sg_init\n", result);
+		goto err_poll;
+	}
+
+	usb_sg_wait(&sgr);
+	if (sgr.status < 0) {
+		dev_err(sur40->dev, "error %d in usb_sg_wait\n", sgr.status);
+		goto err_poll;
+	}
+
+	dev_dbg(sur40->dev, "image acquired\n");
+
+	/* return error if streaming was stopped in the meantime */
+	if (sur40->sequence == -1)
+		return;
+
+	/* mark as finished */
+	new_buf->vb.vb2_buf.timestamp = ktime_get_ns();
+	new_buf->vb.sequence = sur40->sequence++;
+	new_buf->vb.field = V4L2_FIELD_NONE;
+	vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
+	dev_dbg(sur40->dev, "buffer marked done\n");
+	return;
+
+err_poll:
+	vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
+}
+
+/* Initialize input device parameters. */
+static int sur40_input_setup_events(struct input_dev *input_dev)
+{
+	int error;
+
+	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
+			     0, SENSOR_RES_X, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
+			     0, SENSOR_RES_Y, 0, 0);
+
+	input_set_abs_params(input_dev, ABS_MT_TOOL_X,
+			     0, SENSOR_RES_X, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_TOOL_Y,
+			     0, SENSOR_RES_Y, 0, 0);
+
+	/* max value unknown, but major/minor axis
+	 * can never be larger than screen */
+	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
+			     0, SENSOR_RES_X, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR,
+			     0, SENSOR_RES_Y, 0, 0);
+
+	input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
+
+	error = input_mt_init_slots(input_dev, MAX_CONTACTS,
+				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+	if (error) {
+		dev_err(input_dev->dev.parent, "failed to set up slots\n");
+		return error;
+	}
+
+	return 0;
+}
+
+/* Check candidate USB interface. */
+static int sur40_probe(struct usb_interface *interface,
+		       const struct usb_device_id *id)
+{
+	struct usb_device *usbdev = interface_to_usbdev(interface);
+	struct sur40_state *sur40;
+	struct usb_host_interface *iface_desc;
+	struct usb_endpoint_descriptor *endpoint;
+	struct input_dev *input;
+	int error;
+
+	/* Check if we really have the right interface. */
+	iface_desc = interface->cur_altsetting;
+	if (iface_desc->desc.bInterfaceClass != 0xFF)
+		return -ENODEV;
+
+	if (iface_desc->desc.bNumEndpoints < 5)
+		return -ENODEV;
+
+	/* Use endpoint #4 (0x86). */
+	endpoint = &iface_desc->endpoint[4].desc;
+	if (endpoint->bEndpointAddress != TOUCH_ENDPOINT)
+		return -ENODEV;
+
+	/* Allocate memory for our device state and initialize it. */
+	sur40 = kzalloc_obj(*sur40);
+	if (!sur40)
+		return -ENOMEM;
+
+	input = input_allocate_device();
+	if (!input) {
+		error = -ENOMEM;
+		goto err_free_dev;
+	}
+
+	/* initialize locks/lists */
+	INIT_LIST_HEAD(&sur40->buf_list);
+	spin_lock_init(&sur40->qlock);
+	mutex_init(&sur40->lock);
+
+	/* Set up regular input device structure */
+	input->name = DRIVER_LONG;
+	usb_to_input_id(usbdev, &input->id);
+	usb_make_path(usbdev, sur40->phys, sizeof(sur40->phys));
+	strlcat(sur40->phys, "/input0", sizeof(sur40->phys));
+	input->phys = sur40->phys;
+	input->dev.parent = &interface->dev;
+
+	input->open = sur40_open;
+	input->close = sur40_close;
+
+	error = sur40_input_setup_events(input);
+	if (error)
+		goto err_free_input;
+
+	input_set_drvdata(input, sur40);
+	error = input_setup_polling(input, sur40_poll);
+	if (error) {
+		dev_err(&interface->dev, "failed to set up polling");
+		goto err_free_input;
+	}
+
+	input_set_poll_interval(input, POLL_INTERVAL);
+
+	sur40->usbdev = usbdev;
+	sur40->dev = &interface->dev;
+	sur40->input = input;
+
+	/* use the bulk-in endpoint tested above */
+	sur40->bulk_in_size = usb_endpoint_maxp(endpoint);
+	sur40->bulk_in_epaddr = endpoint->bEndpointAddress;
+	sur40->bulk_in_buffer = kmalloc(sur40->bulk_in_size, GFP_KERNEL);
+	if (!sur40->bulk_in_buffer) {
+		dev_err(&interface->dev, "Unable to allocate input buffer.");
+		error = -ENOMEM;
+		goto err_free_input;
+	}
+
+	/* register the video master device */
+	snprintf(sur40->v4l2.name, sizeof(sur40->v4l2.name), "%s", DRIVER_LONG);
+	error = v4l2_device_register(sur40->dev, &sur40->v4l2);
+	if (error) {
+		dev_err(&interface->dev,
+			"Unable to register video master device.");
+		goto err_free_buffer;
+	}
+
+	/* initialize the lock and subdevice */
+	sur40->queue = sur40_queue;
+	sur40->queue.drv_priv = sur40;
+	sur40->queue.lock = &sur40->lock;
+	sur40->queue.dev = sur40->dev;
+
+	/* initialize the queue */
+	error = vb2_queue_init(&sur40->queue);
+	if (error)
+		goto err_unreg_v4l2;
+
+	sur40->pix_fmt = sur40_pix_format[0];
+	sur40->vdev = sur40_video_device;
+	sur40->vdev.v4l2_dev = &sur40->v4l2;
+	sur40->vdev.lock = &sur40->lock;
+	sur40->vdev.queue = &sur40->queue;
+	video_set_drvdata(&sur40->vdev, sur40);
+
+	/* initialize the control handler for 4 controls */
+	v4l2_ctrl_handler_init(&sur40->hdl, 4);
+	sur40->v4l2.ctrl_handler = &sur40->hdl;
+	sur40->vsvideo = (SUR40_CONTRAST_DEF << 4) | SUR40_GAIN_DEF;
+
+	v4l2_ctrl_new_std(&sur40->hdl, &sur40_ctrl_ops, V4L2_CID_BRIGHTNESS,
+	  SUR40_BRIGHTNESS_MIN, SUR40_BRIGHTNESS_MAX, 1, clamp(brightness,
+	  (uint)SUR40_BRIGHTNESS_MIN, (uint)SUR40_BRIGHTNESS_MAX));
+
+	v4l2_ctrl_new_std(&sur40->hdl, &sur40_ctrl_ops, V4L2_CID_CONTRAST,
+	  SUR40_CONTRAST_MIN, SUR40_CONTRAST_MAX, 1, clamp(contrast,
+	  (uint)SUR40_CONTRAST_MIN, (uint)SUR40_CONTRAST_MAX));
+
+	v4l2_ctrl_new_std(&sur40->hdl, &sur40_ctrl_ops, V4L2_CID_GAIN,
+	  SUR40_GAIN_MIN, SUR40_GAIN_MAX, 1, clamp(gain,
+	  (uint)SUR40_GAIN_MIN, (uint)SUR40_GAIN_MAX));
+
+	v4l2_ctrl_new_std(&sur40->hdl, &sur40_ctrl_ops,
+	  V4L2_CID_BACKLIGHT_COMPENSATION, SUR40_BACKLIGHT_MIN,
+	  SUR40_BACKLIGHT_MAX, 1, SUR40_BACKLIGHT_DEF);
+
+	v4l2_ctrl_handler_setup(&sur40->hdl);
+
+	if (sur40->hdl.error) {
+		dev_err(&interface->dev,
+			"Unable to register video controls.");
+		v4l2_ctrl_handler_free(&sur40->hdl);
+		error = sur40->hdl.error;
+		goto err_unreg_v4l2;
+	}
+
+	error = video_register_device(&sur40->vdev, VFL_TYPE_TOUCH, -1);
+	if (error) {
+		dev_err(&interface->dev,
+			"Unable to register video subdevice.");
+		goto err_free_ctrl;
+	}
+
+	/* register the polled input device */
+	error = input_register_device(input);
+	if (error) {
+		dev_err(&interface->dev,
+			"Unable to register polled input device.");
+		goto err_unreg_video;
+	}
+
+	/* we can register the device now, as it is ready */
+	usb_set_intfdata(interface, sur40);
+	dev_dbg(&interface->dev, "%s is now attached\n", DRIVER_DESC);
+
+	return 0;
+
+err_unreg_video:
+	video_unregister_device(&sur40->vdev);
+err_free_ctrl:
+	v4l2_ctrl_handler_free(&sur40->hdl);
+err_unreg_v4l2:
+	v4l2_device_unregister(&sur40->v4l2);
+err_free_buffer:
+	kfree(sur40->bulk_in_buffer);
+err_free_input:
+	input_free_device(input);
+err_free_dev:
+	kfree(sur40);
+
+	return error;
+}
+
+/* Unregister device & clean up. */
+static void sur40_disconnect(struct usb_interface *interface)
+{
+	struct sur40_state *sur40 = usb_get_intfdata(interface);
+
+	input_unregister_device(sur40->input);
+
+	v4l2_ctrl_handler_free(&sur40->hdl);
+	video_unregister_device(&sur40->vdev);
+	v4l2_device_unregister(&sur40->v4l2);
+
+	kfree(sur40->bulk_in_buffer);
+	kfree(sur40);
+
+	usb_set_intfdata(interface, NULL);
+	dev_dbg(&interface->dev, "%s is now disconnected\n", DRIVER_DESC);
+}
+
+/*
+ * Setup the constraints of the queue: besides setting the number of planes
+ * per buffer and the size and allocation context of each plane, it also
+ * checks if sufficient buffers have been allocated. Usually 3 is a good
+ * minimum number: many DMA engines need a minimum of 2 buffers in the
+ * queue and you need to have another available for userspace processing.
+ */
+static int sur40_queue_setup(struct vb2_queue *q,
+		       unsigned int *nbuffers, unsigned int *nplanes,
+		       unsigned int sizes[], struct device *alloc_devs[])
+{
+	struct sur40_state *sur40 = vb2_get_drv_priv(q);
+	unsigned int q_num_bufs = vb2_get_num_buffers(q);
+
+	if (q_num_bufs + *nbuffers < 3)
+		*nbuffers = 3 - q_num_bufs;
+
+	if (*nplanes)
+		return sizes[0] < sur40->pix_fmt.sizeimage ? -EINVAL : 0;
+
+	*nplanes = 1;
+	sizes[0] = sur40->pix_fmt.sizeimage;
+
+	return 0;
+}
+
+/*
+ * Prepare the buffer for queueing to the DMA engine: check and set the
+ * payload size.
+ */
+static int sur40_buffer_prepare(struct vb2_buffer *vb)
+{
+	struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
+	unsigned long size = sur40->pix_fmt.sizeimage;
+
+	if (vb2_plane_size(vb, 0) < size) {
+		dev_err(&sur40->usbdev->dev, "buffer too small (%lu < %lu)\n",
+			 vb2_plane_size(vb, 0), size);
+		return -EINVAL;
+	}
+
+	vb2_set_plane_payload(vb, 0, size);
+	return 0;
+}
+
+/*
+ * Queue this buffer to the DMA engine.
+ */
+static void sur40_buffer_queue(struct vb2_buffer *vb)
+{
+	struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
+	struct sur40_buffer *buf = (struct sur40_buffer *)vb;
+
+	guard(spinlock)(&sur40->qlock);
+	list_add_tail(&buf->list, &sur40->buf_list);
+}
+
+static void return_all_buffers(struct sur40_state *sur40,
+			       enum vb2_buffer_state state)
+{
+	struct sur40_buffer *buf, *node;
+
+	guard(spinlock)(&sur40->qlock);
+
+	list_for_each_entry_safe(buf, node, &sur40->buf_list, list) {
+		vb2_buffer_done(&buf->vb.vb2_buf, state);
+		list_del(&buf->list);
+	}
+}
+
+/*
+ * Start streaming. First check if the minimum number of buffers have been
+ * queued. If not, then return -ENOBUFS and the vb2 framework will call
+ * this function again the next time a buffer has been queued until enough
+ * buffers are available to actually start the DMA engine.
+ */
+static int sur40_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+	struct sur40_state *sur40 = vb2_get_drv_priv(vq);
+
+	sur40->sequence = 0;
+	return 0;
+}
+
+/*
+ * Stop the DMA engine. Any remaining buffers in the DMA queue are dequeued
+ * and passed on to the vb2 framework marked as STATE_ERROR.
+ */
+static void sur40_stop_streaming(struct vb2_queue *vq)
+{
+	struct sur40_state *sur40 = vb2_get_drv_priv(vq);
+	vb2_wait_for_all_buffers(vq);
+	sur40->sequence = -1;
+
+	/* Release all active buffers */
+	return_all_buffers(sur40, VB2_BUF_STATE_ERROR);
+}
+
+/* V4L ioctl */
+static int sur40_vidioc_querycap(struct file *file, void *priv,
+				 struct v4l2_capability *cap)
+{
+	struct sur40_state *sur40 = video_drvdata(file);
+
+	strscpy(cap->driver, DRIVER_SHORT, sizeof(cap->driver));
+	strscpy(cap->card, DRIVER_LONG, sizeof(cap->card));
+	usb_make_path(sur40->usbdev, cap->bus_info, sizeof(cap->bus_info));
+	return 0;
+}
+
+static int sur40_vidioc_enum_input(struct file *file, void *priv,
+				   struct v4l2_input *i)
+{
+	if (i->index != 0)
+		return -EINVAL;
+	i->type = V4L2_INPUT_TYPE_TOUCH;
+	i->std = V4L2_STD_UNKNOWN;
+	strscpy(i->name, "In-Cell Sensor", sizeof(i->name));
+	i->capabilities = 0;
+	return 0;
+}
+
+static int sur40_vidioc_s_input(struct file *file, void *priv, unsigned int i)
+{
+	return (i == 0) ? 0 : -EINVAL;
+}
+
+static int sur40_vidioc_g_input(struct file *file, void *priv, unsigned int *i)
+{
+	*i = 0;
+	return 0;
+}
+
+static int sur40_vidioc_try_fmt(struct file *file, void *priv,
+			    struct v4l2_format *f)
+{
+	switch (f->fmt.pix.pixelformat) {
+	case V4L2_PIX_FMT_GREY:
+		f->fmt.pix = sur40_pix_format[1];
+		break;
+
+	default:
+		f->fmt.pix = sur40_pix_format[0];
+		break;
+	}
+
+	return 0;
+}
+
+static int sur40_vidioc_s_fmt(struct file *file, void *priv,
+			    struct v4l2_format *f)
+{
+	struct sur40_state *sur40 = video_drvdata(file);
+
+	switch (f->fmt.pix.pixelformat) {
+	case V4L2_PIX_FMT_GREY:
+		sur40->pix_fmt = sur40_pix_format[1];
+		break;
+
+	default:
+		sur40->pix_fmt = sur40_pix_format[0];
+		break;
+	}
+
+	f->fmt.pix = sur40->pix_fmt;
+	return 0;
+}
+
+static int sur40_vidioc_g_fmt(struct file *file, void *priv,
+			    struct v4l2_format *f)
+{
+	struct sur40_state *sur40 = video_drvdata(file);
+
+	f->fmt.pix = sur40->pix_fmt;
+	return 0;
+}
+
+static int sur40_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct sur40_state *sur40  = container_of(ctrl->handler,
+	  struct sur40_state, hdl);
+	u8 value = sur40->vsvideo;
+
+	switch (ctrl->id) {
+	case V4L2_CID_BRIGHTNESS:
+		sur40_set_irlevel(sur40, ctrl->val);
+		break;
+	case V4L2_CID_CONTRAST:
+		value = (value & 0x0f) | (ctrl->val << 4);
+		sur40_set_vsvideo(sur40, value);
+		break;
+	case V4L2_CID_GAIN:
+		value = (value & 0xf0) | (ctrl->val);
+		sur40_set_vsvideo(sur40, value);
+		break;
+	case V4L2_CID_BACKLIGHT_COMPENSATION:
+		sur40_set_preprocessor(sur40, ctrl->val);
+		break;
+	}
+	return 0;
+}
+
+static int sur40_ioctl_parm(struct file *file, void *priv,
+			    struct v4l2_streamparm *p)
+{
+	if (p->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
+	p->parm.capture.timeperframe.numerator = 1;
+	p->parm.capture.timeperframe.denominator = 60;
+	p->parm.capture.readbuffers = 3;
+	return 0;
+}
+
+static int sur40_vidioc_enum_fmt(struct file *file, void *priv,
+				 struct v4l2_fmtdesc *f)
+{
+	if (f->index >= ARRAY_SIZE(sur40_pix_format))
+		return -EINVAL;
+
+	f->pixelformat = sur40_pix_format[f->index].pixelformat;
+	f->flags = 0;
+	return 0;
+}
+
+static int sur40_vidioc_enum_framesizes(struct file *file, void *priv,
+					struct v4l2_frmsizeenum *f)
+{
+	struct sur40_state *sur40 = video_drvdata(file);
+
+	if ((f->index != 0) || ((f->pixel_format != V4L2_TCH_FMT_TU08)
+		&& (f->pixel_format != V4L2_PIX_FMT_GREY)))
+		return -EINVAL;
+
+	f->type = V4L2_FRMSIZE_TYPE_DISCRETE;
+	f->discrete.width  = sur40->pix_fmt.width;
+	f->discrete.height = sur40->pix_fmt.height;
+	return 0;
+}
+
+static int sur40_vidioc_enum_frameintervals(struct file *file, void *priv,
+					    struct v4l2_frmivalenum *f)
+{
+	struct sur40_state *sur40 = video_drvdata(file);
+
+	if ((f->index > 0) || ((f->pixel_format != V4L2_TCH_FMT_TU08)
+		&& (f->pixel_format != V4L2_PIX_FMT_GREY))
+		|| (f->width  != sur40->pix_fmt.width)
+		|| (f->height != sur40->pix_fmt.height))
+		return -EINVAL;
+
+	f->type = V4L2_FRMIVAL_TYPE_DISCRETE;
+	f->discrete.denominator  = 60;
+	f->discrete.numerator = 1;
+	return 0;
+}
+
+
+static const struct usb_device_id sur40_table[] = {
+	{ USB_DEVICE(ID_MICROSOFT, ID_SUR40) },  /* Samsung SUR40 */
+	{ }                                      /* terminating null entry */
+};
+MODULE_DEVICE_TABLE(usb, sur40_table);
+
+/* V4L2 structures */
+static const struct vb2_ops sur40_queue_ops = {
+	.queue_setup		= sur40_queue_setup,
+	.buf_prepare		= sur40_buffer_prepare,
+	.buf_queue		= sur40_buffer_queue,
+	.start_streaming	= sur40_start_streaming,
+	.stop_streaming		= sur40_stop_streaming,
+};
+
+static const struct vb2_queue sur40_queue = {
+	.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
+	/*
+	 * VB2_USERPTR in currently not enabled: passing a user pointer to
+	 * dma-sg will result in segment sizes that are not a multiple of
+	 * 512 bytes, which is required by the host controller.
+	*/
+	.io_modes = VB2_MMAP | VB2_READ | VB2_DMABUF,
+	.buf_struct_size = sizeof(struct sur40_buffer),
+	.ops = &sur40_queue_ops,
+	.mem_ops = &vb2_dma_sg_memops,
+	.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC,
+	.min_queued_buffers = 3,
+};
+
+static const struct v4l2_file_operations sur40_video_fops = {
+	.owner = THIS_MODULE,
+	.open = v4l2_fh_open,
+	.release = vb2_fop_release,
+	.unlocked_ioctl = video_ioctl2,
+	.read = vb2_fop_read,
+	.mmap = vb2_fop_mmap,
+	.poll = vb2_fop_poll,
+};
+
+static const struct v4l2_ioctl_ops sur40_video_ioctl_ops = {
+
+	.vidioc_querycap	= sur40_vidioc_querycap,
+
+	.vidioc_enum_fmt_vid_cap = sur40_vidioc_enum_fmt,
+	.vidioc_try_fmt_vid_cap	= sur40_vidioc_try_fmt,
+	.vidioc_s_fmt_vid_cap	= sur40_vidioc_s_fmt,
+	.vidioc_g_fmt_vid_cap	= sur40_vidioc_g_fmt,
+
+	.vidioc_enum_framesizes = sur40_vidioc_enum_framesizes,
+	.vidioc_enum_frameintervals = sur40_vidioc_enum_frameintervals,
+
+	.vidioc_g_parm = sur40_ioctl_parm,
+	.vidioc_s_parm = sur40_ioctl_parm,
+
+	.vidioc_enum_input	= sur40_vidioc_enum_input,
+	.vidioc_g_input		= sur40_vidioc_g_input,
+	.vidioc_s_input		= sur40_vidioc_s_input,
+
+	.vidioc_reqbufs		= vb2_ioctl_reqbufs,
+	.vidioc_create_bufs	= vb2_ioctl_create_bufs,
+	.vidioc_querybuf	= vb2_ioctl_querybuf,
+	.vidioc_qbuf		= vb2_ioctl_qbuf,
+	.vidioc_dqbuf		= vb2_ioctl_dqbuf,
+	.vidioc_expbuf		= vb2_ioctl_expbuf,
+
+	.vidioc_streamon	= vb2_ioctl_streamon,
+	.vidioc_streamoff	= vb2_ioctl_streamoff,
+};
+
+static const struct video_device sur40_video_device = {
+	.name = DRIVER_LONG,
+	.fops = &sur40_video_fops,
+	.ioctl_ops = &sur40_video_ioctl_ops,
+	.release = video_device_release_empty,
+	.device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_TOUCH |
+		       V4L2_CAP_READWRITE | V4L2_CAP_STREAMING,
+};
+
+/* USB-specific object needed to register this driver with the USB subsystem. */
+static struct usb_driver sur40_driver = {
+	.name = DRIVER_SHORT,
+	.probe = sur40_probe,
+	.disconnect = sur40_disconnect,
+	.id_table = sur40_table,
+};
+
+module_usb_driver(sur40_driver);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");