1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Surface2.0/SUR40/PixelSense input driver
4 *
5 * Copyright (c) 2014 by Florian 'floe' Echtler <floe@butterbrot.org>
6 *
7 * Derived from the USB Skeleton driver 1.1,
8 * Copyright (c) 2003 Greg Kroah-Hartman (greg@kroah.com)
9 *
10 * and from the Apple USB BCM5974 multitouch driver,
11 * Copyright (c) 2008 Henrik Rydberg (rydberg@euromail.se)
12 *
13 * and from the generic hid-multitouch driver,
14 * Copyright (c) 2010-2012 Stephane Chatty <chatty@enac.fr>
15 *
16 * and from the v4l2-pci-skeleton driver,
17 * Copyright (c) Copyright 2014 Cisco Systems, Inc.
18 */
19
20#include <linux/kernel.h>
21#include <linux/errno.h>
22#include <linux/delay.h>
23#include <linux/init.h>
24#include <linux/slab.h>
25#include <linux/module.h>
26#include <linux/completion.h>
27#include <linux/uaccess.h>
28#include <linux/usb.h>
29#include <linux/printk.h>
30#include <linux/input.h>
31#include <linux/input/mt.h>
32#include <linux/usb/input.h>
33#include <linux/videodev2.h>
34#include <media/v4l2-device.h>
35#include <media/v4l2-dev.h>
36#include <media/v4l2-ioctl.h>
37#include <media/v4l2-ctrls.h>
38#include <media/videobuf2-v4l2.h>
39#include <media/videobuf2-dma-sg.h>
40
41/* read 512 bytes from endpoint 0x86 -> get header + blobs */
42struct sur40_header {
43
44	__le16 type;       /* always 0x0001 */
45	__le16 count;      /* count of blobs (if 0: continue prev. packet) */
46
47	__le32 packet_id;  /* unique ID for all packets in one frame */
48
49	__le32 timestamp;  /* milliseconds (inc. by 16 or 17 each frame) */
50	__le32 unknown;    /* "epoch?" always 02/03 00 00 00 */
51
52} __packed;
53
54struct sur40_blob {
55
56	__le16 blob_id;
57
58	u8 action;         /* 0x02 = enter/exit, 0x03 = update (?) */
59	u8 type;           /* bitmask (0x01 blob,  0x02 touch, 0x04 tag) */
60
61	__le16 bb_pos_x;   /* upper left corner of bounding box */
62	__le16 bb_pos_y;
63
64	__le16 bb_size_x;  /* size of bounding box */
65	__le16 bb_size_y;
66
67	__le16 pos_x;      /* finger tip position */
68	__le16 pos_y;
69
70	__le16 ctr_x;      /* centroid position */
71	__le16 ctr_y;
72
73	__le16 axis_x;     /* somehow related to major/minor axis, mostly: */
74	__le16 axis_y;     /* axis_x == bb_size_y && axis_y == bb_size_x */
75
76	__le32 angle;      /* orientation in radians relative to x axis -
77	                      actually an IEEE754 float, don't use in kernel */
78
79	__le32 area;       /* size in pixels/pressure (?) */
80
81	u8 padding[24];
82
83	__le32 tag_id;     /* valid when type == 0x04 (SUR40_TAG) */
84	__le32 unknown;
85
86} __packed;
87
88/* combined header/blob data */
89struct sur40_data {
90	struct sur40_header header;
91	struct sur40_blob   blobs[];
92} __packed;
93
94/* read 512 bytes from endpoint 0x82 -> get header below
95 * continue reading 16k blocks until header.size bytes read */
96struct sur40_image_header {
97	__le32 magic;     /* "SUBF" */
98	__le32 packet_id;
99	__le32 size;      /* always 0x0007e900 = 960x540 */
100	__le32 timestamp; /* milliseconds (increases by 16 or 17 each frame) */
101	__le32 unknown;   /* "epoch?" always 02/03 00 00 00 */
102} __packed;
103
104/* version information */
105#define DRIVER_SHORT   "sur40"
106#define DRIVER_LONG    "Samsung SUR40"
107#define DRIVER_AUTHOR  "Florian 'floe' Echtler <floe@butterbrot.org>"
108#define DRIVER_DESC    "Surface2.0/SUR40/PixelSense input driver"
109
110/* vendor and device IDs */
111#define ID_MICROSOFT 0x045e
112#define ID_SUR40     0x0775
113
114/* sensor resolution */
115#define SENSOR_RES_X 1920
116#define SENSOR_RES_Y 1080
117
118/* touch data endpoint */
119#define TOUCH_ENDPOINT 0x86
120
121/* video data endpoint */
122#define VIDEO_ENDPOINT 0x82
123
124/* video header fields */
125#define VIDEO_HEADER_MAGIC 0x46425553
126#define VIDEO_PACKET_SIZE  16384
127
128/* polling interval (ms) */
129#define POLL_INTERVAL 1
130
131/* maximum number of contacts FIXME: this is a guess? */
132#define MAX_CONTACTS 64
133
134/* control commands */
135#define SUR40_GET_VERSION 0xb0 /* 12 bytes string    */
136#define SUR40_ACCEL_CAPS  0xb3 /*  5 bytes           */
137#define SUR40_SENSOR_CAPS 0xc1 /* 24 bytes           */
138
139#define SUR40_POKE        0xc5 /* poke register byte */
140#define SUR40_PEEK        0xc4 /* 48 bytes registers */
141
142#define SUR40_GET_STATE   0xc5 /*  4 bytes state (?) */
143#define SUR40_GET_SENSORS 0xb1 /*  8 bytes sensors   */
144
145#define SUR40_BLOB	0x01
146#define SUR40_TOUCH	0x02
147#define SUR40_TAG	0x04
148
149/* video controls */
150#define SUR40_BRIGHTNESS_MAX 0xff
151#define SUR40_BRIGHTNESS_MIN 0x00
152#define SUR40_BRIGHTNESS_DEF 0xff
153
154#define SUR40_CONTRAST_MAX 0x0f
155#define SUR40_CONTRAST_MIN 0x00
156#define SUR40_CONTRAST_DEF 0x0a
157
158#define SUR40_GAIN_MAX 0x09
159#define SUR40_GAIN_MIN 0x00
160#define SUR40_GAIN_DEF 0x08
161
162#define SUR40_BACKLIGHT_MAX 0x01
163#define SUR40_BACKLIGHT_MIN 0x00
164#define SUR40_BACKLIGHT_DEF 0x01
165
166#define sur40_str(s) #s
167#define SUR40_PARAM_RANGE(lo, hi) " (range " sur40_str(lo) "-" sur40_str(hi) ")"
168
169/* module parameters */
170static uint brightness = SUR40_BRIGHTNESS_DEF;
171module_param(brightness, uint, 0644);
172MODULE_PARM_DESC(brightness, "set initial brightness"
173	SUR40_PARAM_RANGE(SUR40_BRIGHTNESS_MIN, SUR40_BRIGHTNESS_MAX));
174static uint contrast = SUR40_CONTRAST_DEF;
175module_param(contrast, uint, 0644);
176MODULE_PARM_DESC(contrast, "set initial contrast"
177	SUR40_PARAM_RANGE(SUR40_CONTRAST_MIN, SUR40_CONTRAST_MAX));
178static uint gain = SUR40_GAIN_DEF;
179module_param(gain, uint, 0644);
180MODULE_PARM_DESC(gain, "set initial gain"
181	SUR40_PARAM_RANGE(SUR40_GAIN_MIN, SUR40_GAIN_MAX));
182
183static const struct v4l2_pix_format sur40_pix_format[] = {
184	{
185		.pixelformat = V4L2_TCH_FMT_TU08,
186		.width  = SENSOR_RES_X / 2,
187		.height = SENSOR_RES_Y / 2,
188		.field = V4L2_FIELD_NONE,
189		.colorspace = V4L2_COLORSPACE_RAW,
190		.bytesperline = SENSOR_RES_X / 2,
191		.sizeimage = (SENSOR_RES_X/2) * (SENSOR_RES_Y/2),
192	},
193	{
194		.pixelformat = V4L2_PIX_FMT_GREY,
195		.width  = SENSOR_RES_X / 2,
196		.height = SENSOR_RES_Y / 2,
197		.field = V4L2_FIELD_NONE,
198		.colorspace = V4L2_COLORSPACE_RAW,
199		.bytesperline = SENSOR_RES_X / 2,
200		.sizeimage = (SENSOR_RES_X/2) * (SENSOR_RES_Y/2),
201	}
202};
203
204/* master device state */
205struct sur40_state {
206
207	struct usb_device *usbdev;
208	struct device *dev;
209	struct input_dev *input;
210
211	struct v4l2_device v4l2;
212	struct video_device vdev;
213	struct mutex lock;
214	struct v4l2_pix_format pix_fmt;
215	struct v4l2_ctrl_handler hdl;
216
217	struct vb2_queue queue;
218	struct list_head buf_list;
219	spinlock_t qlock;
220	int sequence;
221
222	struct sur40_data *bulk_in_buffer;
223	size_t bulk_in_size;
224	u8 bulk_in_epaddr;
225	u8 vsvideo;
226
227	char phys[64];
228};
229
230struct sur40_buffer {
231	struct vb2_v4l2_buffer vb;
232	struct list_head list;
233};
234
235/* forward declarations */
236static const struct video_device sur40_video_device;
237static const struct vb2_queue sur40_queue;
238static void sur40_process_video(struct sur40_state *sur40);
239static int sur40_s_ctrl(struct v4l2_ctrl *ctrl);
240
241static const struct v4l2_ctrl_ops sur40_ctrl_ops = {
242	.s_ctrl = sur40_s_ctrl,
243};
244
245/*
246 * Note: an earlier, non-public version of this driver used USB_RECIP_ENDPOINT
247 * here by mistake which is very likely to have corrupted the firmware EEPROM
248 * on two separate SUR40 devices. Thanks to Alan Stern who spotted this bug.
249 * Should you ever run into a similar problem, the background story to this
250 * incident and instructions on how to fix the corrupted EEPROM are available
251 * at https://floe.butterbrot.org/matrix/hacking/surface/brick.html
252*/
253
254/* command wrapper */
255static int sur40_command(struct sur40_state *dev,
256			 u8 command, u16 index, void *buffer, u16 size)
257{
258	return usb_control_msg(dev->usbdev, usb_rcvctrlpipe(dev->usbdev, 0),
259			       command,
260			       USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
261			       0x00, index, buffer, size, 1000);
262}
263
264/* poke a byte in the panel register space */
265static int sur40_poke(struct sur40_state *dev, u8 offset, u8 value)
266{
267	int result;
268	u8 index = 0x96; // 0xae for permanent write
269
270	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
271		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
272		0x32, index, NULL, 0, 1000);
273	if (result < 0)
274		goto error;
275	msleep(5);
276
277	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
278		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
279		0x72, offset, NULL, 0, 1000);
280	if (result < 0)
281		goto error;
282	msleep(5);
283
284	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
285		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
286		0xb2, value, NULL, 0, 1000);
287	if (result < 0)
288		goto error;
289	msleep(5);
290
291error:
292	return result;
293}
294
295static int sur40_set_preprocessor(struct sur40_state *dev, u8 value)
296{
297	u8 setting_07[2] = { 0x01, 0x00 };
298	u8 setting_17[2] = { 0x85, 0x80 };
299	int result;
300
301	if (value > 1)
302		return -ERANGE;
303
304	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
305		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
306		0x07, setting_07[value], NULL, 0, 1000);
307	if (result < 0)
308		goto error;
309	msleep(5);
310
311	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
312		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
313		0x17, setting_17[value], NULL, 0, 1000);
314	if (result < 0)
315		goto error;
316	msleep(5);
317
318error:
319	return result;
320}
321
322static void sur40_set_vsvideo(struct sur40_state *handle, u8 value)
323{
324	int i;
325
326	for (i = 0; i < 4; i++)
327		sur40_poke(handle, 0x1c+i, value);
328	handle->vsvideo = value;
329}
330
331static void sur40_set_irlevel(struct sur40_state *handle, u8 value)
332{
333	int i;
334
335	for (i = 0; i < 8; i++)
336		sur40_poke(handle, 0x08+(2*i), value);
337}
338
339/* Initialization routine, called from sur40_open */
340static int sur40_init(struct sur40_state *dev)
341{
342	int result;
343	u8 *buffer;
344
345	buffer = kmalloc(24, GFP_KERNEL);
346	if (!buffer) {
347		result = -ENOMEM;
348		goto error;
349	}
350
351	/* stupidly replay the original MS driver init sequence */
352	result = sur40_command(dev, SUR40_GET_VERSION, 0x00, buffer, 12);
353	if (result < 0)
354		goto error;
355
356	result = sur40_command(dev, SUR40_GET_VERSION, 0x01, buffer, 12);
357	if (result < 0)
358		goto error;
359
360	result = sur40_command(dev, SUR40_GET_VERSION, 0x02, buffer, 12);
361	if (result < 0)
362		goto error;
363
364	result = sur40_command(dev, SUR40_SENSOR_CAPS, 0x00, buffer, 24);
365	if (result < 0)
366		goto error;
367
368	result = sur40_command(dev, SUR40_ACCEL_CAPS, 0x00, buffer, 5);
369	if (result < 0)
370		goto error;
371
372	result = sur40_command(dev, SUR40_GET_VERSION, 0x03, buffer, 12);
373	if (result < 0)
374		goto error;
375
376	result = 0;
377
378	/*
379	 * Discard the result buffer - no known data inside except
380	 * some version strings, maybe extract these sometime...
381	 */
382error:
383	kfree(buffer);
384	return result;
385}
386
387/*
388 * Callback routines from input_dev
389 */
390
391/* Enable the device, polling will now start. */
392static int sur40_open(struct input_dev *input)
393{
394	struct sur40_state *sur40 = input_get_drvdata(input);
395
396	dev_dbg(sur40->dev, "open\n");
397	return sur40_init(sur40);
398}
399
400/* Disable device, polling has stopped. */
401static void sur40_close(struct input_dev *input)
402{
403	struct sur40_state *sur40 = input_get_drvdata(input);
404
405	dev_dbg(sur40->dev, "close\n");
406	/*
407	 * There is no known way to stop the device, so we simply
408	 * stop polling.
409	 */
410}
411
412/*
413 * This function is called when a whole contact has been processed,
414 * so that it can assign it to a slot and store the data there.
415 */
416static void sur40_report_blob(struct sur40_blob *blob, struct input_dev *input)
417{
418	int wide, major, minor;
419	int bb_size_x, bb_size_y, pos_x, pos_y, ctr_x, ctr_y, slotnum;
420
421	if (blob->type != SUR40_TOUCH)
422		return;
423
424	slotnum = input_mt_get_slot_by_key(input, blob->blob_id);
425	if (slotnum < 0 || slotnum >= MAX_CONTACTS)
426		return;
427
428	bb_size_x = le16_to_cpu(blob->bb_size_x);
429	bb_size_y = le16_to_cpu(blob->bb_size_y);
430
431	pos_x = le16_to_cpu(blob->pos_x);
432	pos_y = le16_to_cpu(blob->pos_y);
433
434	ctr_x = le16_to_cpu(blob->ctr_x);
435	ctr_y = le16_to_cpu(blob->ctr_y);
436
437	input_mt_slot(input, slotnum);
438	input_mt_report_slot_state(input, MT_TOOL_FINGER, 1);
439	wide = (bb_size_x > bb_size_y);
440	major = max(bb_size_x, bb_size_y);
441	minor = min(bb_size_x, bb_size_y);
442
443	input_report_abs(input, ABS_MT_POSITION_X, pos_x);
444	input_report_abs(input, ABS_MT_POSITION_Y, pos_y);
445	input_report_abs(input, ABS_MT_TOOL_X, ctr_x);
446	input_report_abs(input, ABS_MT_TOOL_Y, ctr_y);
447
448	/* TODO: use a better orientation measure */
449	input_report_abs(input, ABS_MT_ORIENTATION, wide);
450	input_report_abs(input, ABS_MT_TOUCH_MAJOR, major);
451	input_report_abs(input, ABS_MT_TOUCH_MINOR, minor);
452}
453
454/* core function: poll for new input data */
455static void sur40_poll(struct input_dev *input)
456{
457	struct sur40_state *sur40 = input_get_drvdata(input);
458	int result, bulk_read, need_blobs, packet_blobs, i;
459	struct sur40_header *header = &sur40->bulk_in_buffer->header;
460	struct sur40_blob *inblob = &sur40->bulk_in_buffer->blobs[0];
461
462	dev_dbg(sur40->dev, "poll\n");
463
464	need_blobs = -1;
465
466	do {
467
468		/* perform a blocking bulk read to get data from the device */
469		result = usb_bulk_msg(sur40->usbdev,
470			usb_rcvbulkpipe(sur40->usbdev, sur40->bulk_in_epaddr),
471			sur40->bulk_in_buffer, sur40->bulk_in_size,
472			&bulk_read, 1000);
473
474		dev_dbg(sur40->dev, "received %d bytes\n", bulk_read);
475
476		if (result < 0) {
477			dev_err(sur40->dev, "error in usb_bulk_read\n");
478			return;
479		}
480
481		result = bulk_read - sizeof(struct sur40_header);
482
483		if (result % sizeof(struct sur40_blob) != 0) {
484			dev_err(sur40->dev, "transfer size mismatch\n");
485			return;
486		}
487
488		/* first packet? */
489		if (need_blobs == -1) {
490			need_blobs = le16_to_cpu(header->count);
491			dev_dbg(sur40->dev, "need %d blobs\n", need_blobs);
492			/* packet_id = le32_to_cpu(header->packet_id); */
493		}
494
495		/*
496		 * Sanity check. when video data is also being retrieved, the
497		 * packet ID will usually increase in the middle of a series
498		 * instead of at the end. However, the data is still consistent,
499		 * so the packet ID is probably just valid for the first packet
500		 * in a series.
501
502		if (packet_id != le32_to_cpu(header->packet_id))
503			dev_dbg(sur40->dev, "packet ID mismatch\n");
504		 */
505
506		packet_blobs = result / sizeof(struct sur40_blob);
507		dev_dbg(sur40->dev, "received %d blobs\n", packet_blobs);
508
509		/* packets always contain at least 4 blobs, even if empty */
510		if (packet_blobs > need_blobs)
511			packet_blobs = need_blobs;
512
513		for (i = 0; i < packet_blobs; i++) {
514			need_blobs--;
515			dev_dbg(sur40->dev, "processing blob\n");
516			sur40_report_blob(&(inblob[i]), input);
517		}
518
519	} while (need_blobs > 0);
520
521	input_mt_sync_frame(input);
522	input_sync(input);
523
524	sur40_process_video(sur40);
525}
526
527/* deal with video data */
528static void sur40_process_video(struct sur40_state *sur40)
529{
530
531	struct sur40_image_header *img = (void *)(sur40->bulk_in_buffer);
532	struct sur40_buffer *new_buf;
533	struct usb_sg_request sgr;
534	struct sg_table *sgt;
535	int result, bulk_read;
536
537	if (!vb2_start_streaming_called(&sur40->queue))
538		return;
539
540	/* get a new buffer from the list */
541	spin_lock(&sur40->qlock);
542	if (list_empty(&sur40->buf_list)) {
543		dev_dbg(sur40->dev, "buffer queue empty\n");
544		spin_unlock(&sur40->qlock);
545		return;
546	}
547	new_buf = list_entry(sur40->buf_list.next, struct sur40_buffer, list);
548	list_del(&new_buf->list);
549	spin_unlock(&sur40->qlock);
550
551	dev_dbg(sur40->dev, "buffer acquired\n");
552
553	/* retrieve data via bulk read */
554	result = usb_bulk_msg(sur40->usbdev,
555			usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT),
556			sur40->bulk_in_buffer, sur40->bulk_in_size,
557			&bulk_read, 1000);
558
559	if (result < 0) {
560		dev_err(sur40->dev, "error in usb_bulk_read\n");
561		goto err_poll;
562	}
563
564	if (bulk_read != sizeof(struct sur40_image_header)) {
565		dev_err(sur40->dev, "received %d bytes (%zd expected)\n",
566			bulk_read, sizeof(struct sur40_image_header));
567		goto err_poll;
568	}
569
570	if (le32_to_cpu(img->magic) != VIDEO_HEADER_MAGIC) {
571		dev_err(sur40->dev, "image magic mismatch\n");
572		goto err_poll;
573	}
574
575	if (le32_to_cpu(img->size) != sur40->pix_fmt.sizeimage) {
576		dev_err(sur40->dev, "image size mismatch\n");
577		goto err_poll;
578	}
579
580	dev_dbg(sur40->dev, "header acquired\n");
581
582	sgt = vb2_dma_sg_plane_desc(&new_buf->vb.vb2_buf, 0);
583
584	result = usb_sg_init(&sgr, sur40->usbdev,
585		usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT), 0,
586		sgt->sgl, sgt->nents, sur40->pix_fmt.sizeimage, 0);
587	if (result < 0) {
588		dev_err(sur40->dev, "error %d in usb_sg_init\n", result);
589		goto err_poll;
590	}
591
592	usb_sg_wait(&sgr);
593	if (sgr.status < 0) {
594		dev_err(sur40->dev, "error %d in usb_sg_wait\n", sgr.status);
595		goto err_poll;
596	}
597
598	dev_dbg(sur40->dev, "image acquired\n");
599
600	/* return error if streaming was stopped in the meantime */
601	if (sur40->sequence == -1)
602		return;
603
604	/* mark as finished */
605	new_buf->vb.vb2_buf.timestamp = ktime_get_ns();
606	new_buf->vb.sequence = sur40->sequence++;
607	new_buf->vb.field = V4L2_FIELD_NONE;
608	vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
609	dev_dbg(sur40->dev, "buffer marked done\n");
610	return;
611
612err_poll:
613	vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
614}
615
616/* Initialize input device parameters. */
617static int sur40_input_setup_events(struct input_dev *input_dev)
618{
619	int error;
620
621	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
622			     0, SENSOR_RES_X, 0, 0);
623	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
624			     0, SENSOR_RES_Y, 0, 0);
625
626	input_set_abs_params(input_dev, ABS_MT_TOOL_X,
627			     0, SENSOR_RES_X, 0, 0);
628	input_set_abs_params(input_dev, ABS_MT_TOOL_Y,
629			     0, SENSOR_RES_Y, 0, 0);
630
631	/* max value unknown, but major/minor axis
632	 * can never be larger than screen */
633	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
634			     0, SENSOR_RES_X, 0, 0);
635	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR,
636			     0, SENSOR_RES_Y, 0, 0);
637
638	input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
639
640	error = input_mt_init_slots(input_dev, MAX_CONTACTS,
641				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
642	if (error) {
643		dev_err(input_dev->dev.parent, "failed to set up slots\n");
644		return error;
645	}
646
647	return 0;
648}
649
650/* Check candidate USB interface. */
651static int sur40_probe(struct usb_interface *interface,
652		       const struct usb_device_id *id)
653{
654	struct usb_device *usbdev = interface_to_usbdev(interface);
655	struct sur40_state *sur40;
656	struct usb_host_interface *iface_desc;
657	struct usb_endpoint_descriptor *endpoint;
658	struct input_dev *input;
659	int error;
660
661	/* Check if we really have the right interface. */
662	iface_desc = interface->cur_altsetting;
663	if (iface_desc->desc.bInterfaceClass != 0xFF)
664		return -ENODEV;
665
666	if (iface_desc->desc.bNumEndpoints < 5)
667		return -ENODEV;
668
669	/* Use endpoint #4 (0x86). */
670	endpoint = &iface_desc->endpoint[4].desc;
671	if (endpoint->bEndpointAddress != TOUCH_ENDPOINT)
672		return -ENODEV;
673
674	/* Allocate memory for our device state and initialize it. */
675	sur40 = kzalloc(sizeof(struct sur40_state), GFP_KERNEL);
676	if (!sur40)
677		return -ENOMEM;
678
679	input = input_allocate_device();
680	if (!input) {
681		error = -ENOMEM;
682		goto err_free_dev;
683	}
684
685	/* initialize locks/lists */
686	INIT_LIST_HEAD(&sur40->buf_list);
687	spin_lock_init(&sur40->qlock);
688	mutex_init(&sur40->lock);
689
690	/* Set up regular input device structure */
691	input->name = DRIVER_LONG;
692	usb_to_input_id(usbdev, &input->id);
693	usb_make_path(usbdev, sur40->phys, sizeof(sur40->phys));
694	strlcat(sur40->phys, "/input0", sizeof(sur40->phys));
695	input->phys = sur40->phys;
696	input->dev.parent = &interface->dev;
697
698	input->open = sur40_open;
699	input->close = sur40_close;
700
701	error = sur40_input_setup_events(input);
702	if (error)
703		goto err_free_input;
704
705	input_set_drvdata(input, sur40);
706	error = input_setup_polling(input, sur40_poll);
707	if (error) {
708		dev_err(&interface->dev, "failed to set up polling");
709		goto err_free_input;
710	}
711
712	input_set_poll_interval(input, POLL_INTERVAL);
713
714	sur40->usbdev = usbdev;
715	sur40->dev = &interface->dev;
716	sur40->input = input;
717
718	/* use the bulk-in endpoint tested above */
719	sur40->bulk_in_size = usb_endpoint_maxp(endpoint);
720	sur40->bulk_in_epaddr = endpoint->bEndpointAddress;
721	sur40->bulk_in_buffer = kmalloc(sur40->bulk_in_size, GFP_KERNEL);
722	if (!sur40->bulk_in_buffer) {
723		dev_err(&interface->dev, "Unable to allocate input buffer.");
724		error = -ENOMEM;
725		goto err_free_input;
726	}
727
728	/* register the polled input device */
729	error = input_register_device(input);
730	if (error) {
731		dev_err(&interface->dev,
732			"Unable to register polled input device.");
733		goto err_free_buffer;
734	}
735
736	/* register the video master device */
737	snprintf(sur40->v4l2.name, sizeof(sur40->v4l2.name), "%s", DRIVER_LONG);
738	error = v4l2_device_register(sur40->dev, &sur40->v4l2);
739	if (error) {
740		dev_err(&interface->dev,
741			"Unable to register video master device.");
742		goto err_unreg_v4l2;
743	}
744
745	/* initialize the lock and subdevice */
746	sur40->queue = sur40_queue;
747	sur40->queue.drv_priv = sur40;
748	sur40->queue.lock = &sur40->lock;
749	sur40->queue.dev = sur40->dev;
750
751	/* initialize the queue */
752	error = vb2_queue_init(&sur40->queue);
753	if (error)
754		goto err_unreg_v4l2;
755
756	sur40->pix_fmt = sur40_pix_format[0];
757	sur40->vdev = sur40_video_device;
758	sur40->vdev.v4l2_dev = &sur40->v4l2;
759	sur40->vdev.lock = &sur40->lock;
760	sur40->vdev.queue = &sur40->queue;
761	video_set_drvdata(&sur40->vdev, sur40);
762
763	/* initialize the control handler for 4 controls */
764	v4l2_ctrl_handler_init(&sur40->hdl, 4);
765	sur40->v4l2.ctrl_handler = &sur40->hdl;
766	sur40->vsvideo = (SUR40_CONTRAST_DEF << 4) | SUR40_GAIN_DEF;
767
768	v4l2_ctrl_new_std(&sur40->hdl, &sur40_ctrl_ops, V4L2_CID_BRIGHTNESS,
769	  SUR40_BRIGHTNESS_MIN, SUR40_BRIGHTNESS_MAX, 1, clamp(brightness,
770	  (uint)SUR40_BRIGHTNESS_MIN, (uint)SUR40_BRIGHTNESS_MAX));
771
772	v4l2_ctrl_new_std(&sur40->hdl, &sur40_ctrl_ops, V4L2_CID_CONTRAST,
773	  SUR40_CONTRAST_MIN, SUR40_CONTRAST_MAX, 1, clamp(contrast,
774	  (uint)SUR40_CONTRAST_MIN, (uint)SUR40_CONTRAST_MAX));
775
776	v4l2_ctrl_new_std(&sur40->hdl, &sur40_ctrl_ops, V4L2_CID_GAIN,
777	  SUR40_GAIN_MIN, SUR40_GAIN_MAX, 1, clamp(gain,
778	  (uint)SUR40_GAIN_MIN, (uint)SUR40_GAIN_MAX));
779
780	v4l2_ctrl_new_std(&sur40->hdl, &sur40_ctrl_ops,
781	  V4L2_CID_BACKLIGHT_COMPENSATION, SUR40_BACKLIGHT_MIN,
782	  SUR40_BACKLIGHT_MAX, 1, SUR40_BACKLIGHT_DEF);
783
784	v4l2_ctrl_handler_setup(&sur40->hdl);
785
786	if (sur40->hdl.error) {
787		dev_err(&interface->dev,
788			"Unable to register video controls.");
789		v4l2_ctrl_handler_free(&sur40->hdl);
790		error = sur40->hdl.error;
791		goto err_unreg_v4l2;
792	}
793
794	error = video_register_device(&sur40->vdev, VFL_TYPE_TOUCH, -1);
795	if (error) {
796		dev_err(&interface->dev,
797			"Unable to register video subdevice.");
798		goto err_unreg_video;
799	}
800
801	/* we can register the device now, as it is ready */
802	usb_set_intfdata(interface, sur40);
803	dev_dbg(&interface->dev, "%s is now attached\n", DRIVER_DESC);
804
805	return 0;
806
807err_unreg_video:
808	video_unregister_device(&sur40->vdev);
809err_unreg_v4l2:
810	v4l2_device_unregister(&sur40->v4l2);
811err_free_buffer:
812	kfree(sur40->bulk_in_buffer);
813err_free_input:
814	input_free_device(input);
815err_free_dev:
816	kfree(sur40);
817
818	return error;
819}
820
821/* Unregister device & clean up. */
822static void sur40_disconnect(struct usb_interface *interface)
823{
824	struct sur40_state *sur40 = usb_get_intfdata(interface);
825
826	v4l2_ctrl_handler_free(&sur40->hdl);
827	video_unregister_device(&sur40->vdev);
828	v4l2_device_unregister(&sur40->v4l2);
829
830	input_unregister_device(sur40->input);
831	kfree(sur40->bulk_in_buffer);
832	kfree(sur40);
833
834	usb_set_intfdata(interface, NULL);
835	dev_dbg(&interface->dev, "%s is now disconnected\n", DRIVER_DESC);
836}
837
838/*
839 * Setup the constraints of the queue: besides setting the number of planes
840 * per buffer and the size and allocation context of each plane, it also
841 * checks if sufficient buffers have been allocated. Usually 3 is a good
842 * minimum number: many DMA engines need a minimum of 2 buffers in the
843 * queue and you need to have another available for userspace processing.
844 */
845static int sur40_queue_setup(struct vb2_queue *q,
846		       unsigned int *nbuffers, unsigned int *nplanes,
847		       unsigned int sizes[], struct device *alloc_devs[])
848{
849	struct sur40_state *sur40 = vb2_get_drv_priv(q);
850
851	if (q->num_buffers + *nbuffers < 3)
852		*nbuffers = 3 - q->num_buffers;
853
854	if (*nplanes)
855		return sizes[0] < sur40->pix_fmt.sizeimage ? -EINVAL : 0;
856
857	*nplanes = 1;
858	sizes[0] = sur40->pix_fmt.sizeimage;
859
860	return 0;
861}
862
863/*
864 * Prepare the buffer for queueing to the DMA engine: check and set the
865 * payload size.
866 */
867static int sur40_buffer_prepare(struct vb2_buffer *vb)
868{
869	struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
870	unsigned long size = sur40->pix_fmt.sizeimage;
871
872	if (vb2_plane_size(vb, 0) < size) {
873		dev_err(&sur40->usbdev->dev, "buffer too small (%lu < %lu)\n",
874			 vb2_plane_size(vb, 0), size);
875		return -EINVAL;
876	}
877
878	vb2_set_plane_payload(vb, 0, size);
879	return 0;
880}
881
882/*
883 * Queue this buffer to the DMA engine.
884 */
885static void sur40_buffer_queue(struct vb2_buffer *vb)
886{
887	struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
888	struct sur40_buffer *buf = (struct sur40_buffer *)vb;
889
890	spin_lock(&sur40->qlock);
891	list_add_tail(&buf->list, &sur40->buf_list);
892	spin_unlock(&sur40->qlock);
893}
894
895static void return_all_buffers(struct sur40_state *sur40,
896			       enum vb2_buffer_state state)
897{
898	struct sur40_buffer *buf, *node;
899
900	spin_lock(&sur40->qlock);
901	list_for_each_entry_safe(buf, node, &sur40->buf_list, list) {
902		vb2_buffer_done(&buf->vb.vb2_buf, state);
903		list_del(&buf->list);
904	}
905	spin_unlock(&sur40->qlock);
906}
907
908/*
909 * Start streaming. First check if the minimum number of buffers have been
910 * queued. If not, then return -ENOBUFS and the vb2 framework will call
911 * this function again the next time a buffer has been queued until enough
912 * buffers are available to actually start the DMA engine.
913 */
914static int sur40_start_streaming(struct vb2_queue *vq, unsigned int count)
915{
916	struct sur40_state *sur40 = vb2_get_drv_priv(vq);
917
918	sur40->sequence = 0;
919	return 0;
920}
921
922/*
923 * Stop the DMA engine. Any remaining buffers in the DMA queue are dequeued
924 * and passed on to the vb2 framework marked as STATE_ERROR.
925 */
926static void sur40_stop_streaming(struct vb2_queue *vq)
927{
928	struct sur40_state *sur40 = vb2_get_drv_priv(vq);
929	vb2_wait_for_all_buffers(vq);
930	sur40->sequence = -1;
931
932	/* Release all active buffers */
933	return_all_buffers(sur40, VB2_BUF_STATE_ERROR);
934}
935
936/* V4L ioctl */
937static int sur40_vidioc_querycap(struct file *file, void *priv,
938				 struct v4l2_capability *cap)
939{
940	struct sur40_state *sur40 = video_drvdata(file);
941
942	strscpy(cap->driver, DRIVER_SHORT, sizeof(cap->driver));
943	strscpy(cap->card, DRIVER_LONG, sizeof(cap->card));
944	usb_make_path(sur40->usbdev, cap->bus_info, sizeof(cap->bus_info));
945	return 0;
946}
947
948static int sur40_vidioc_enum_input(struct file *file, void *priv,
949				   struct v4l2_input *i)
950{
951	if (i->index != 0)
952		return -EINVAL;
953	i->type = V4L2_INPUT_TYPE_TOUCH;
954	i->std = V4L2_STD_UNKNOWN;
955	strscpy(i->name, "In-Cell Sensor", sizeof(i->name));
956	i->capabilities = 0;
957	return 0;
958}
959
960static int sur40_vidioc_s_input(struct file *file, void *priv, unsigned int i)
961{
962	return (i == 0) ? 0 : -EINVAL;
963}
964
965static int sur40_vidioc_g_input(struct file *file, void *priv, unsigned int *i)
966{
967	*i = 0;
968	return 0;
969}
970
971static int sur40_vidioc_try_fmt(struct file *file, void *priv,
972			    struct v4l2_format *f)
973{
974	switch (f->fmt.pix.pixelformat) {
975	case V4L2_PIX_FMT_GREY:
976		f->fmt.pix = sur40_pix_format[1];
977		break;
978
979	default:
980		f->fmt.pix = sur40_pix_format[0];
981		break;
982	}
983
984	return 0;
985}
986
987static int sur40_vidioc_s_fmt(struct file *file, void *priv,
988			    struct v4l2_format *f)
989{
990	struct sur40_state *sur40 = video_drvdata(file);
991
992	switch (f->fmt.pix.pixelformat) {
993	case V4L2_PIX_FMT_GREY:
994		sur40->pix_fmt = sur40_pix_format[1];
995		break;
996
997	default:
998		sur40->pix_fmt = sur40_pix_format[0];
999		break;
1000	}
1001
1002	f->fmt.pix = sur40->pix_fmt;
1003	return 0;
1004}
1005
1006static int sur40_vidioc_g_fmt(struct file *file, void *priv,
1007			    struct v4l2_format *f)
1008{
1009	struct sur40_state *sur40 = video_drvdata(file);
1010
1011	f->fmt.pix = sur40->pix_fmt;
1012	return 0;
1013}
1014
1015static int sur40_s_ctrl(struct v4l2_ctrl *ctrl)
1016{
1017	struct sur40_state *sur40  = container_of(ctrl->handler,
1018	  struct sur40_state, hdl);
1019	u8 value = sur40->vsvideo;
1020
1021	switch (ctrl->id) {
1022	case V4L2_CID_BRIGHTNESS:
1023		sur40_set_irlevel(sur40, ctrl->val);
1024		break;
1025	case V4L2_CID_CONTRAST:
1026		value = (value & 0x0f) | (ctrl->val << 4);
1027		sur40_set_vsvideo(sur40, value);
1028		break;
1029	case V4L2_CID_GAIN:
1030		value = (value & 0xf0) | (ctrl->val);
1031		sur40_set_vsvideo(sur40, value);
1032		break;
1033	case V4L2_CID_BACKLIGHT_COMPENSATION:
1034		sur40_set_preprocessor(sur40, ctrl->val);
1035		break;
1036	}
1037	return 0;
1038}
1039
1040static int sur40_ioctl_parm(struct file *file, void *priv,
1041			    struct v4l2_streamparm *p)
1042{
1043	if (p->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1044		return -EINVAL;
1045
1046	p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
1047	p->parm.capture.timeperframe.numerator = 1;
1048	p->parm.capture.timeperframe.denominator = 60;
1049	p->parm.capture.readbuffers = 3;
1050	return 0;
1051}
1052
1053static int sur40_vidioc_enum_fmt(struct file *file, void *priv,
1054				 struct v4l2_fmtdesc *f)
1055{
1056	if (f->index >= ARRAY_SIZE(sur40_pix_format))
1057		return -EINVAL;
1058
1059	f->pixelformat = sur40_pix_format[f->index].pixelformat;
1060	f->flags = 0;
1061	return 0;
1062}
1063
1064static int sur40_vidioc_enum_framesizes(struct file *file, void *priv,
1065					struct v4l2_frmsizeenum *f)
1066{
1067	struct sur40_state *sur40 = video_drvdata(file);
1068
1069	if ((f->index != 0) || ((f->pixel_format != V4L2_TCH_FMT_TU08)
1070		&& (f->pixel_format != V4L2_PIX_FMT_GREY)))
1071		return -EINVAL;
1072
1073	f->type = V4L2_FRMSIZE_TYPE_DISCRETE;
1074	f->discrete.width  = sur40->pix_fmt.width;
1075	f->discrete.height = sur40->pix_fmt.height;
1076	return 0;
1077}
1078
1079static int sur40_vidioc_enum_frameintervals(struct file *file, void *priv,
1080					    struct v4l2_frmivalenum *f)
1081{
1082	struct sur40_state *sur40 = video_drvdata(file);
1083
1084	if ((f->index > 0) || ((f->pixel_format != V4L2_TCH_FMT_TU08)
1085		&& (f->pixel_format != V4L2_PIX_FMT_GREY))
1086		|| (f->width  != sur40->pix_fmt.width)
1087		|| (f->height != sur40->pix_fmt.height))
1088		return -EINVAL;
1089
1090	f->type = V4L2_FRMIVAL_TYPE_DISCRETE;
1091	f->discrete.denominator  = 60;
1092	f->discrete.numerator = 1;
1093	return 0;
1094}
1095
1096
1097static const struct usb_device_id sur40_table[] = {
1098	{ USB_DEVICE(ID_MICROSOFT, ID_SUR40) },  /* Samsung SUR40 */
1099	{ }                                      /* terminating null entry */
1100};
1101MODULE_DEVICE_TABLE(usb, sur40_table);
1102
1103/* V4L2 structures */
1104static const struct vb2_ops sur40_queue_ops = {
1105	.queue_setup		= sur40_queue_setup,
1106	.buf_prepare		= sur40_buffer_prepare,
1107	.buf_queue		= sur40_buffer_queue,
1108	.start_streaming	= sur40_start_streaming,
1109	.stop_streaming		= sur40_stop_streaming,
1110	.wait_prepare		= vb2_ops_wait_prepare,
1111	.wait_finish		= vb2_ops_wait_finish,
1112};
1113
1114static const struct vb2_queue sur40_queue = {
1115	.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
1116	/*
1117	 * VB2_USERPTR in currently not enabled: passing a user pointer to
1118	 * dma-sg will result in segment sizes that are not a multiple of
1119	 * 512 bytes, which is required by the host controller.
1120	*/
1121	.io_modes = VB2_MMAP | VB2_READ | VB2_DMABUF,
1122	.buf_struct_size = sizeof(struct sur40_buffer),
1123	.ops = &sur40_queue_ops,
1124	.mem_ops = &vb2_dma_sg_memops,
1125	.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC,
1126	.min_buffers_needed = 3,
1127};
1128
1129static const struct v4l2_file_operations sur40_video_fops = {
1130	.owner = THIS_MODULE,
1131	.open = v4l2_fh_open,
1132	.release = vb2_fop_release,
1133	.unlocked_ioctl = video_ioctl2,
1134	.read = vb2_fop_read,
1135	.mmap = vb2_fop_mmap,
1136	.poll = vb2_fop_poll,
1137};
1138
1139static const struct v4l2_ioctl_ops sur40_video_ioctl_ops = {
1140
1141	.vidioc_querycap	= sur40_vidioc_querycap,
1142
1143	.vidioc_enum_fmt_vid_cap = sur40_vidioc_enum_fmt,
1144	.vidioc_try_fmt_vid_cap	= sur40_vidioc_try_fmt,
1145	.vidioc_s_fmt_vid_cap	= sur40_vidioc_s_fmt,
1146	.vidioc_g_fmt_vid_cap	= sur40_vidioc_g_fmt,
1147
1148	.vidioc_enum_framesizes = sur40_vidioc_enum_framesizes,
1149	.vidioc_enum_frameintervals = sur40_vidioc_enum_frameintervals,
1150
1151	.vidioc_g_parm = sur40_ioctl_parm,
1152	.vidioc_s_parm = sur40_ioctl_parm,
1153
1154	.vidioc_enum_input	= sur40_vidioc_enum_input,
1155	.vidioc_g_input		= sur40_vidioc_g_input,
1156	.vidioc_s_input		= sur40_vidioc_s_input,
1157
1158	.vidioc_reqbufs		= vb2_ioctl_reqbufs,
1159	.vidioc_create_bufs	= vb2_ioctl_create_bufs,
1160	.vidioc_querybuf	= vb2_ioctl_querybuf,
1161	.vidioc_qbuf		= vb2_ioctl_qbuf,
1162	.vidioc_dqbuf		= vb2_ioctl_dqbuf,
1163	.vidioc_expbuf		= vb2_ioctl_expbuf,
1164
1165	.vidioc_streamon	= vb2_ioctl_streamon,
1166	.vidioc_streamoff	= vb2_ioctl_streamoff,
1167};
1168
1169static const struct video_device sur40_video_device = {
1170	.name = DRIVER_LONG,
1171	.fops = &sur40_video_fops,
1172	.ioctl_ops = &sur40_video_ioctl_ops,
1173	.release = video_device_release_empty,
1174	.device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_TOUCH |
1175		       V4L2_CAP_READWRITE | V4L2_CAP_STREAMING,
1176};
1177
1178/* USB-specific object needed to register this driver with the USB subsystem. */
1179static struct usb_driver sur40_driver = {
1180	.name = DRIVER_SHORT,
1181	.probe = sur40_probe,
1182	.disconnect = sur40_disconnect,
1183	.id_table = sur40_table,
1184};
1185
1186module_usb_driver(sur40_driver);
1187
1188MODULE_AUTHOR(DRIVER_AUTHOR);
1189MODULE_DESCRIPTION(DRIVER_DESC);
1190MODULE_LICENSE("GPL");
1191