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 */
42 struct 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 
54 struct 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 */
89 struct 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 */
96 struct 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 */
170 static uint brightness = SUR40_BRIGHTNESS_DEF;
171 module_param(brightness, uint, 0644);
172 MODULE_PARM_DESC(brightness, "set initial brightness"
173 	SUR40_PARAM_RANGE(SUR40_BRIGHTNESS_MIN, SUR40_BRIGHTNESS_MAX));
174 static uint contrast = SUR40_CONTRAST_DEF;
175 module_param(contrast, uint, 0644);
176 MODULE_PARM_DESC(contrast, "set initial contrast"
177 	SUR40_PARAM_RANGE(SUR40_CONTRAST_MIN, SUR40_CONTRAST_MAX));
178 static uint gain = SUR40_GAIN_DEF;
179 module_param(gain, uint, 0644);
180 MODULE_PARM_DESC(gain, "set initial gain"
181 	SUR40_PARAM_RANGE(SUR40_GAIN_MIN, SUR40_GAIN_MAX));
182 
183 static 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 */
205 struct 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 
230 struct sur40_buffer {
231 	struct vb2_v4l2_buffer vb;
232 	struct list_head list;
233 };
234 
235 /* forward declarations */
236 static const struct video_device sur40_video_device;
237 static const struct vb2_queue sur40_queue;
238 static void sur40_process_video(struct sur40_state *sur40);
239 static int sur40_s_ctrl(struct v4l2_ctrl *ctrl);
240 
241 static 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 */
255 static 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 */
265 static 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 
291 error:
292 	return result;
293 }
294 
295 static 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 
318 error:
319 	return result;
320 }
321 
322 static 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 
331 static 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 */
340 static 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 	 */
382 error:
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. */
392 static 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. */
401 static 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  */
416 static 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 */
455 static 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 */
528 static 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 
612 err_poll:
613 	vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
614 }
615 
616 /* Initialize input device parameters. */
617 static 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. */
651 static 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 
807 err_unreg_video:
808 	video_unregister_device(&sur40->vdev);
809 err_unreg_v4l2:
810 	v4l2_device_unregister(&sur40->v4l2);
811 err_free_buffer:
812 	kfree(sur40->bulk_in_buffer);
813 err_free_input:
814 	input_free_device(input);
815 err_free_dev:
816 	kfree(sur40);
817 
818 	return error;
819 }
820 
821 /* Unregister device & clean up. */
822 static 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  */
845 static 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  */
867 static 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  */
885 static 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 
895 static 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  */
914 static 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  */
926 static 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 */
937 static 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 
948 static 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 
960 static int sur40_vidioc_s_input(struct file *file, void *priv, unsigned int i)
961 {
962 	return (i == 0) ? 0 : -EINVAL;
963 }
964 
965 static int sur40_vidioc_g_input(struct file *file, void *priv, unsigned int *i)
966 {
967 	*i = 0;
968 	return 0;
969 }
970 
971 static 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 
987 static 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 
1006 static 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 
1015 static 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 
1040 static 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 
1053 static 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 
1064 static 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 
1079 static 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 
1097 static const struct usb_device_id sur40_table[] = {
1098 	{ USB_DEVICE(ID_MICROSOFT, ID_SUR40) },  /* Samsung SUR40 */
1099 	{ }                                      /* terminating null entry */
1100 };
1101 MODULE_DEVICE_TABLE(usb, sur40_table);
1102 
1103 /* V4L2 structures */
1104 static 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 
1114 static 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 
1129 static 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 
1139 static 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 
1169 static 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. */
1179 static struct usb_driver sur40_driver = {
1180 	.name = DRIVER_SHORT,
1181 	.probe = sur40_probe,
1182 	.disconnect = sur40_disconnect,
1183 	.id_table = sur40_table,
1184 };
1185 
1186 module_usb_driver(sur40_driver);
1187 
1188 MODULE_AUTHOR(DRIVER_AUTHOR);
1189 MODULE_DESCRIPTION(DRIVER_DESC);
1190 MODULE_LICENSE("GPL");
1191