1 /*
2  * Surface2.0/SUR40/PixelSense input driver
3  *
4  * Copyright (c) 2014 by Florian 'floe' Echtler <floe@butterbrot.org>
5  *
6  * Derived from the USB Skeleton driver 1.1,
7  * Copyright (c) 2003 Greg Kroah-Hartman (greg@kroah.com)
8  *
9  * and from the Apple USB BCM5974 multitouch driver,
10  * Copyright (c) 2008 Henrik Rydberg (rydberg@euromail.se)
11  *
12  * and from the generic hid-multitouch driver,
13  * Copyright (c) 2010-2012 Stephane Chatty <chatty@enac.fr>
14  *
15  * and from the v4l2-pci-skeleton driver,
16  * Copyright (c) Copyright 2014 Cisco Systems, Inc.
17  *
18  * This program is free software; you can redistribute it and/or
19  * modify it under the terms of the GNU General Public License as
20  * published by the Free Software Foundation; either version 2 of
21  * the License, or (at your option) any later version.
22  */
23 
24 #include <linux/kernel.h>
25 #include <linux/errno.h>
26 #include <linux/delay.h>
27 #include <linux/init.h>
28 #include <linux/slab.h>
29 #include <linux/module.h>
30 #include <linux/completion.h>
31 #include <linux/uaccess.h>
32 #include <linux/usb.h>
33 #include <linux/printk.h>
34 #include <linux/input-polldev.h>
35 #include <linux/input/mt.h>
36 #include <linux/usb/input.h>
37 #include <linux/videodev2.h>
38 #include <media/v4l2-device.h>
39 #include <media/v4l2-dev.h>
40 #include <media/v4l2-ioctl.h>
41 #include <media/v4l2-ctrls.h>
42 #include <media/videobuf2-v4l2.h>
43 #include <media/videobuf2-dma-sg.h>
44 
45 /* read 512 bytes from endpoint 0x86 -> get header + blobs */
46 struct sur40_header {
47 
48 	__le16 type;       /* always 0x0001 */
49 	__le16 count;      /* count of blobs (if 0: continue prev. packet) */
50 
51 	__le32 packet_id;  /* unique ID for all packets in one frame */
52 
53 	__le32 timestamp;  /* milliseconds (inc. by 16 or 17 each frame) */
54 	__le32 unknown;    /* "epoch?" always 02/03 00 00 00 */
55 
56 } __packed;
57 
58 struct sur40_blob {
59 
60 	__le16 blob_id;
61 
62 	u8 action;         /* 0x02 = enter/exit, 0x03 = update (?) */
63 	u8 type;           /* bitmask (0x01 blob,  0x02 touch, 0x04 tag) */
64 
65 	__le16 bb_pos_x;   /* upper left corner of bounding box */
66 	__le16 bb_pos_y;
67 
68 	__le16 bb_size_x;  /* size of bounding box */
69 	__le16 bb_size_y;
70 
71 	__le16 pos_x;      /* finger tip position */
72 	__le16 pos_y;
73 
74 	__le16 ctr_x;      /* centroid position */
75 	__le16 ctr_y;
76 
77 	__le16 axis_x;     /* somehow related to major/minor axis, mostly: */
78 	__le16 axis_y;     /* axis_x == bb_size_y && axis_y == bb_size_x */
79 
80 	__le32 angle;      /* orientation in radians relative to x axis -
81 	                      actually an IEEE754 float, don't use in kernel */
82 
83 	__le32 area;       /* size in pixels/pressure (?) */
84 
85 	u8 padding[24];
86 
87 	__le32 tag_id;     /* valid when type == 0x04 (SUR40_TAG) */
88 	__le32 unknown;
89 
90 } __packed;
91 
92 /* combined header/blob data */
93 struct sur40_data {
94 	struct sur40_header header;
95 	struct sur40_blob   blobs[];
96 } __packed;
97 
98 /* read 512 bytes from endpoint 0x82 -> get header below
99  * continue reading 16k blocks until header.size bytes read */
100 struct sur40_image_header {
101 	__le32 magic;     /* "SUBF" */
102 	__le32 packet_id;
103 	__le32 size;      /* always 0x0007e900 = 960x540 */
104 	__le32 timestamp; /* milliseconds (increases by 16 or 17 each frame) */
105 	__le32 unknown;   /* "epoch?" always 02/03 00 00 00 */
106 } __packed;
107 
108 /* version information */
109 #define DRIVER_SHORT   "sur40"
110 #define DRIVER_LONG    "Samsung SUR40"
111 #define DRIVER_AUTHOR  "Florian 'floe' Echtler <floe@butterbrot.org>"
112 #define DRIVER_DESC    "Surface2.0/SUR40/PixelSense input driver"
113 
114 /* vendor and device IDs */
115 #define ID_MICROSOFT 0x045e
116 #define ID_SUR40     0x0775
117 
118 /* sensor resolution */
119 #define SENSOR_RES_X 1920
120 #define SENSOR_RES_Y 1080
121 
122 /* touch data endpoint */
123 #define TOUCH_ENDPOINT 0x86
124 
125 /* video data endpoint */
126 #define VIDEO_ENDPOINT 0x82
127 
128 /* video header fields */
129 #define VIDEO_HEADER_MAGIC 0x46425553
130 #define VIDEO_PACKET_SIZE  16384
131 
132 /* polling interval (ms) */
133 #define POLL_INTERVAL 1
134 
135 /* maximum number of contacts FIXME: this is a guess? */
136 #define MAX_CONTACTS 64
137 
138 /* control commands */
139 #define SUR40_GET_VERSION 0xb0 /* 12 bytes string    */
140 #define SUR40_ACCEL_CAPS  0xb3 /*  5 bytes           */
141 #define SUR40_SENSOR_CAPS 0xc1 /* 24 bytes           */
142 
143 #define SUR40_POKE        0xc5 /* poke register byte */
144 #define SUR40_PEEK        0xc4 /* 48 bytes registers */
145 
146 #define SUR40_GET_STATE   0xc5 /*  4 bytes state (?) */
147 #define SUR40_GET_SENSORS 0xb1 /*  8 bytes sensors   */
148 
149 #define SUR40_BLOB	0x01
150 #define SUR40_TOUCH	0x02
151 #define SUR40_TAG	0x04
152 
153 /* video controls */
154 #define SUR40_BRIGHTNESS_MAX 0xff
155 #define SUR40_BRIGHTNESS_MIN 0x00
156 #define SUR40_BRIGHTNESS_DEF 0xff
157 
158 #define SUR40_CONTRAST_MAX 0x0f
159 #define SUR40_CONTRAST_MIN 0x00
160 #define SUR40_CONTRAST_DEF 0x0a
161 
162 #define SUR40_GAIN_MAX 0x09
163 #define SUR40_GAIN_MIN 0x00
164 #define SUR40_GAIN_DEF 0x08
165 
166 #define SUR40_BACKLIGHT_MAX 0x01
167 #define SUR40_BACKLIGHT_MIN 0x00
168 #define SUR40_BACKLIGHT_DEF 0x01
169 
170 #define sur40_str(s) #s
171 #define SUR40_PARAM_RANGE(lo, hi) " (range " sur40_str(lo) "-" sur40_str(hi) ")"
172 
173 /* module parameters */
174 static uint brightness = SUR40_BRIGHTNESS_DEF;
175 module_param(brightness, uint, 0644);
176 MODULE_PARM_DESC(brightness, "set initial brightness"
177 	SUR40_PARAM_RANGE(SUR40_BRIGHTNESS_MIN, SUR40_BRIGHTNESS_MAX));
178 static uint contrast = SUR40_CONTRAST_DEF;
179 module_param(contrast, uint, 0644);
180 MODULE_PARM_DESC(contrast, "set initial contrast"
181 	SUR40_PARAM_RANGE(SUR40_CONTRAST_MIN, SUR40_CONTRAST_MAX));
182 static uint gain = SUR40_GAIN_DEF;
183 module_param(gain, uint, 0644);
184 MODULE_PARM_DESC(gain, "set initial gain"
185 	SUR40_PARAM_RANGE(SUR40_GAIN_MIN, SUR40_GAIN_MAX));
186 
187 static const struct v4l2_pix_format sur40_pix_format[] = {
188 	{
189 		.pixelformat = V4L2_TCH_FMT_TU08,
190 		.width  = SENSOR_RES_X / 2,
191 		.height = SENSOR_RES_Y / 2,
192 		.field = V4L2_FIELD_NONE,
193 		.colorspace = V4L2_COLORSPACE_SRGB,
194 		.bytesperline = SENSOR_RES_X / 2,
195 		.sizeimage = (SENSOR_RES_X/2) * (SENSOR_RES_Y/2),
196 	},
197 	{
198 		.pixelformat = V4L2_PIX_FMT_GREY,
199 		.width  = SENSOR_RES_X / 2,
200 		.height = SENSOR_RES_Y / 2,
201 		.field = V4L2_FIELD_NONE,
202 		.colorspace = V4L2_COLORSPACE_SRGB,
203 		.bytesperline = SENSOR_RES_X / 2,
204 		.sizeimage = (SENSOR_RES_X/2) * (SENSOR_RES_Y/2),
205 	}
206 };
207 
208 /* master device state */
209 struct sur40_state {
210 
211 	struct usb_device *usbdev;
212 	struct device *dev;
213 	struct input_polled_dev *input;
214 
215 	struct v4l2_device v4l2;
216 	struct video_device vdev;
217 	struct mutex lock;
218 	struct v4l2_pix_format pix_fmt;
219 	struct v4l2_ctrl_handler hdl;
220 
221 	struct vb2_queue queue;
222 	struct list_head buf_list;
223 	spinlock_t qlock;
224 	int sequence;
225 
226 	struct sur40_data *bulk_in_buffer;
227 	size_t bulk_in_size;
228 	u8 bulk_in_epaddr;
229 	u8 vsvideo;
230 
231 	char phys[64];
232 };
233 
234 struct sur40_buffer {
235 	struct vb2_v4l2_buffer vb;
236 	struct list_head list;
237 };
238 
239 /* forward declarations */
240 static const struct video_device sur40_video_device;
241 static const struct vb2_queue sur40_queue;
242 static void sur40_process_video(struct sur40_state *sur40);
243 static int sur40_s_ctrl(struct v4l2_ctrl *ctrl);
244 
245 static const struct v4l2_ctrl_ops sur40_ctrl_ops = {
246 	.s_ctrl = sur40_s_ctrl,
247 };
248 
249 /*
250  * Note: an earlier, non-public version of this driver used USB_RECIP_ENDPOINT
251  * here by mistake which is very likely to have corrupted the firmware EEPROM
252  * on two separate SUR40 devices. Thanks to Alan Stern who spotted this bug.
253  * Should you ever run into a similar problem, the background story to this
254  * incident and instructions on how to fix the corrupted EEPROM are available
255  * at https://floe.butterbrot.org/matrix/hacking/surface/brick.html
256 */
257 
258 /* command wrapper */
259 static int sur40_command(struct sur40_state *dev,
260 			 u8 command, u16 index, void *buffer, u16 size)
261 {
262 	return usb_control_msg(dev->usbdev, usb_rcvctrlpipe(dev->usbdev, 0),
263 			       command,
264 			       USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
265 			       0x00, index, buffer, size, 1000);
266 }
267 
268 /* poke a byte in the panel register space */
269 static int sur40_poke(struct sur40_state *dev, u8 offset, u8 value)
270 {
271 	int result;
272 	u8 index = 0x96; // 0xae for permanent write
273 
274 	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
275 		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
276 		0x32, index, NULL, 0, 1000);
277 	if (result < 0)
278 		goto error;
279 	msleep(5);
280 
281 	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
282 		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
283 		0x72, offset, NULL, 0, 1000);
284 	if (result < 0)
285 		goto error;
286 	msleep(5);
287 
288 	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
289 		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
290 		0xb2, value, NULL, 0, 1000);
291 	if (result < 0)
292 		goto error;
293 	msleep(5);
294 
295 error:
296 	return result;
297 }
298 
299 static int sur40_set_preprocessor(struct sur40_state *dev, u8 value)
300 {
301 	u8 setting_07[2] = { 0x01, 0x00 };
302 	u8 setting_17[2] = { 0x85, 0x80 };
303 	int result;
304 
305 	if (value > 1)
306 		return -ERANGE;
307 
308 	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
309 		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
310 		0x07, setting_07[value], NULL, 0, 1000);
311 	if (result < 0)
312 		goto error;
313 	msleep(5);
314 
315 	result = usb_control_msg(dev->usbdev, usb_sndctrlpipe(dev->usbdev, 0),
316 		SUR40_POKE, USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
317 		0x17, setting_17[value], NULL, 0, 1000);
318 	if (result < 0)
319 		goto error;
320 	msleep(5);
321 
322 error:
323 	return result;
324 }
325 
326 static void sur40_set_vsvideo(struct sur40_state *handle, u8 value)
327 {
328 	int i;
329 
330 	for (i = 0; i < 4; i++)
331 		sur40_poke(handle, 0x1c+i, value);
332 	handle->vsvideo = value;
333 }
334 
335 static void sur40_set_irlevel(struct sur40_state *handle, u8 value)
336 {
337 	int i;
338 
339 	for (i = 0; i < 8; i++)
340 		sur40_poke(handle, 0x08+(2*i), value);
341 }
342 
343 /* Initialization routine, called from sur40_open */
344 static int sur40_init(struct sur40_state *dev)
345 {
346 	int result;
347 	u8 *buffer;
348 
349 	buffer = kmalloc(24, GFP_KERNEL);
350 	if (!buffer) {
351 		result = -ENOMEM;
352 		goto error;
353 	}
354 
355 	/* stupidly replay the original MS driver init sequence */
356 	result = sur40_command(dev, SUR40_GET_VERSION, 0x00, buffer, 12);
357 	if (result < 0)
358 		goto error;
359 
360 	result = sur40_command(dev, SUR40_GET_VERSION, 0x01, buffer, 12);
361 	if (result < 0)
362 		goto error;
363 
364 	result = sur40_command(dev, SUR40_GET_VERSION, 0x02, buffer, 12);
365 	if (result < 0)
366 		goto error;
367 
368 	result = sur40_command(dev, SUR40_SENSOR_CAPS, 0x00, buffer, 24);
369 	if (result < 0)
370 		goto error;
371 
372 	result = sur40_command(dev, SUR40_ACCEL_CAPS, 0x00, buffer, 5);
373 	if (result < 0)
374 		goto error;
375 
376 	result = sur40_command(dev, SUR40_GET_VERSION, 0x03, buffer, 12);
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_polled_dev
389  */
390 
391 /* Enable the device, polling will now start. */
392 static void sur40_open(struct input_polled_dev *polldev)
393 {
394 	struct sur40_state *sur40 = polldev->private;
395 
396 	dev_dbg(sur40->dev, "open\n");
397 	sur40_init(sur40);
398 }
399 
400 /* Disable device, polling has stopped. */
401 static void sur40_close(struct input_polled_dev *polldev)
402 {
403 	struct sur40_state *sur40 = polldev->private;
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_polled_dev *polldev)
456 {
457 	struct sur40_state *sur40 = polldev->private;
458 	struct input_dev *input = polldev->input;
459 	int result, bulk_read, need_blobs, packet_blobs, i;
460 	u32 uninitialized_var(packet_id);
461 
462 	struct sur40_header *header = &sur40->bulk_in_buffer->header;
463 	struct sur40_blob *inblob = &sur40->bulk_in_buffer->blobs[0];
464 
465 	dev_dbg(sur40->dev, "poll\n");
466 
467 	need_blobs = -1;
468 
469 	do {
470 
471 		/* perform a blocking bulk read to get data from the device */
472 		result = usb_bulk_msg(sur40->usbdev,
473 			usb_rcvbulkpipe(sur40->usbdev, sur40->bulk_in_epaddr),
474 			sur40->bulk_in_buffer, sur40->bulk_in_size,
475 			&bulk_read, 1000);
476 
477 		dev_dbg(sur40->dev, "received %d bytes\n", bulk_read);
478 
479 		if (result < 0) {
480 			dev_err(sur40->dev, "error in usb_bulk_read\n");
481 			return;
482 		}
483 
484 		result = bulk_read - sizeof(struct sur40_header);
485 
486 		if (result % sizeof(struct sur40_blob) != 0) {
487 			dev_err(sur40->dev, "transfer size mismatch\n");
488 			return;
489 		}
490 
491 		/* first packet? */
492 		if (need_blobs == -1) {
493 			need_blobs = le16_to_cpu(header->count);
494 			dev_dbg(sur40->dev, "need %d blobs\n", need_blobs);
495 			packet_id = le32_to_cpu(header->packet_id);
496 		}
497 
498 		/*
499 		 * Sanity check. when video data is also being retrieved, the
500 		 * packet ID will usually increase in the middle of a series
501 		 * instead of at the end. However, the data is still consistent,
502 		 * so the packet ID is probably just valid for the first packet
503 		 * in a series.
504 
505 		if (packet_id != le32_to_cpu(header->packet_id))
506 			dev_dbg(sur40->dev, "packet ID mismatch\n");
507 		 */
508 
509 		packet_blobs = result / sizeof(struct sur40_blob);
510 		dev_dbg(sur40->dev, "received %d blobs\n", packet_blobs);
511 
512 		/* packets always contain at least 4 blobs, even if empty */
513 		if (packet_blobs > need_blobs)
514 			packet_blobs = need_blobs;
515 
516 		for (i = 0; i < packet_blobs; i++) {
517 			need_blobs--;
518 			dev_dbg(sur40->dev, "processing blob\n");
519 			sur40_report_blob(&(inblob[i]), input);
520 		}
521 
522 	} while (need_blobs > 0);
523 
524 	input_mt_sync_frame(input);
525 	input_sync(input);
526 
527 	sur40_process_video(sur40);
528 }
529 
530 /* deal with video data */
531 static void sur40_process_video(struct sur40_state *sur40)
532 {
533 
534 	struct sur40_image_header *img = (void *)(sur40->bulk_in_buffer);
535 	struct sur40_buffer *new_buf;
536 	struct usb_sg_request sgr;
537 	struct sg_table *sgt;
538 	int result, bulk_read;
539 
540 	if (!vb2_start_streaming_called(&sur40->queue))
541 		return;
542 
543 	/* get a new buffer from the list */
544 	spin_lock(&sur40->qlock);
545 	if (list_empty(&sur40->buf_list)) {
546 		dev_dbg(sur40->dev, "buffer queue empty\n");
547 		spin_unlock(&sur40->qlock);
548 		return;
549 	}
550 	new_buf = list_entry(sur40->buf_list.next, struct sur40_buffer, list);
551 	list_del(&new_buf->list);
552 	spin_unlock(&sur40->qlock);
553 
554 	dev_dbg(sur40->dev, "buffer acquired\n");
555 
556 	/* retrieve data via bulk read */
557 	result = usb_bulk_msg(sur40->usbdev,
558 			usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT),
559 			sur40->bulk_in_buffer, sur40->bulk_in_size,
560 			&bulk_read, 1000);
561 
562 	if (result < 0) {
563 		dev_err(sur40->dev, "error in usb_bulk_read\n");
564 		goto err_poll;
565 	}
566 
567 	if (bulk_read != sizeof(struct sur40_image_header)) {
568 		dev_err(sur40->dev, "received %d bytes (%zd expected)\n",
569 			bulk_read, sizeof(struct sur40_image_header));
570 		goto err_poll;
571 	}
572 
573 	if (le32_to_cpu(img->magic) != VIDEO_HEADER_MAGIC) {
574 		dev_err(sur40->dev, "image magic mismatch\n");
575 		goto err_poll;
576 	}
577 
578 	if (le32_to_cpu(img->size) != sur40->pix_fmt.sizeimage) {
579 		dev_err(sur40->dev, "image size mismatch\n");
580 		goto err_poll;
581 	}
582 
583 	dev_dbg(sur40->dev, "header acquired\n");
584 
585 	sgt = vb2_dma_sg_plane_desc(&new_buf->vb.vb2_buf, 0);
586 
587 	result = usb_sg_init(&sgr, sur40->usbdev,
588 		usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT), 0,
589 		sgt->sgl, sgt->nents, sur40->pix_fmt.sizeimage, 0);
590 	if (result < 0) {
591 		dev_err(sur40->dev, "error %d in usb_sg_init\n", result);
592 		goto err_poll;
593 	}
594 
595 	usb_sg_wait(&sgr);
596 	if (sgr.status < 0) {
597 		dev_err(sur40->dev, "error %d in usb_sg_wait\n", sgr.status);
598 		goto err_poll;
599 	}
600 
601 	dev_dbg(sur40->dev, "image acquired\n");
602 
603 	/* return error if streaming was stopped in the meantime */
604 	if (sur40->sequence == -1)
605 		return;
606 
607 	/* mark as finished */
608 	new_buf->vb.vb2_buf.timestamp = ktime_get_ns();
609 	new_buf->vb.sequence = sur40->sequence++;
610 	new_buf->vb.field = V4L2_FIELD_NONE;
611 	vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
612 	dev_dbg(sur40->dev, "buffer marked done\n");
613 	return;
614 
615 err_poll:
616 	vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
617 }
618 
619 /* Initialize input device parameters. */
620 static void sur40_input_setup(struct input_dev *input_dev)
621 {
622 	__set_bit(EV_KEY, input_dev->evbit);
623 	__set_bit(EV_ABS, input_dev->evbit);
624 
625 	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
626 			     0, SENSOR_RES_X, 0, 0);
627 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
628 			     0, SENSOR_RES_Y, 0, 0);
629 
630 	input_set_abs_params(input_dev, ABS_MT_TOOL_X,
631 			     0, SENSOR_RES_X, 0, 0);
632 	input_set_abs_params(input_dev, ABS_MT_TOOL_Y,
633 			     0, SENSOR_RES_Y, 0, 0);
634 
635 	/* max value unknown, but major/minor axis
636 	 * can never be larger than screen */
637 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
638 			     0, SENSOR_RES_X, 0, 0);
639 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR,
640 			     0, SENSOR_RES_Y, 0, 0);
641 
642 	input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
643 
644 	input_mt_init_slots(input_dev, MAX_CONTACTS,
645 			    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
646 }
647 
648 /* Check candidate USB interface. */
649 static int sur40_probe(struct usb_interface *interface,
650 		       const struct usb_device_id *id)
651 {
652 	struct usb_device *usbdev = interface_to_usbdev(interface);
653 	struct sur40_state *sur40;
654 	struct usb_host_interface *iface_desc;
655 	struct usb_endpoint_descriptor *endpoint;
656 	struct input_polled_dev *poll_dev;
657 	int error;
658 
659 	/* Check if we really have the right interface. */
660 	iface_desc = &interface->altsetting[0];
661 	if (iface_desc->desc.bInterfaceClass != 0xFF)
662 		return -ENODEV;
663 
664 	if (iface_desc->desc.bNumEndpoints < 5)
665 		return -ENODEV;
666 
667 	/* Use endpoint #4 (0x86). */
668 	endpoint = &iface_desc->endpoint[4].desc;
669 	if (endpoint->bEndpointAddress != TOUCH_ENDPOINT)
670 		return -ENODEV;
671 
672 	/* Allocate memory for our device state and initialize it. */
673 	sur40 = kzalloc(sizeof(struct sur40_state), GFP_KERNEL);
674 	if (!sur40)
675 		return -ENOMEM;
676 
677 	poll_dev = input_allocate_polled_device();
678 	if (!poll_dev) {
679 		error = -ENOMEM;
680 		goto err_free_dev;
681 	}
682 
683 	/* initialize locks/lists */
684 	INIT_LIST_HEAD(&sur40->buf_list);
685 	spin_lock_init(&sur40->qlock);
686 	mutex_init(&sur40->lock);
687 
688 	/* Set up polled input device control structure */
689 	poll_dev->private = sur40;
690 	poll_dev->poll_interval = POLL_INTERVAL;
691 	poll_dev->open = sur40_open;
692 	poll_dev->poll = sur40_poll;
693 	poll_dev->close = sur40_close;
694 
695 	/* Set up regular input device structure */
696 	sur40_input_setup(poll_dev->input);
697 
698 	poll_dev->input->name = DRIVER_LONG;
699 	usb_to_input_id(usbdev, &poll_dev->input->id);
700 	usb_make_path(usbdev, sur40->phys, sizeof(sur40->phys));
701 	strlcat(sur40->phys, "/input0", sizeof(sur40->phys));
702 	poll_dev->input->phys = sur40->phys;
703 	poll_dev->input->dev.parent = &interface->dev;
704 
705 	sur40->usbdev = usbdev;
706 	sur40->dev = &interface->dev;
707 	sur40->input = poll_dev;
708 
709 	/* use the bulk-in endpoint tested above */
710 	sur40->bulk_in_size = usb_endpoint_maxp(endpoint);
711 	sur40->bulk_in_epaddr = endpoint->bEndpointAddress;
712 	sur40->bulk_in_buffer = kmalloc(sur40->bulk_in_size, GFP_KERNEL);
713 	if (!sur40->bulk_in_buffer) {
714 		dev_err(&interface->dev, "Unable to allocate input buffer.");
715 		error = -ENOMEM;
716 		goto err_free_polldev;
717 	}
718 
719 	/* register the polled input device */
720 	error = input_register_polled_device(poll_dev);
721 	if (error) {
722 		dev_err(&interface->dev,
723 			"Unable to register polled input device.");
724 		goto err_free_buffer;
725 	}
726 
727 	/* register the video master device */
728 	snprintf(sur40->v4l2.name, sizeof(sur40->v4l2.name), "%s", DRIVER_LONG);
729 	error = v4l2_device_register(sur40->dev, &sur40->v4l2);
730 	if (error) {
731 		dev_err(&interface->dev,
732 			"Unable to register video master device.");
733 		goto err_unreg_v4l2;
734 	}
735 
736 	/* initialize the lock and subdevice */
737 	sur40->queue = sur40_queue;
738 	sur40->queue.drv_priv = sur40;
739 	sur40->queue.lock = &sur40->lock;
740 	sur40->queue.dev = sur40->dev;
741 
742 	/* initialize the queue */
743 	error = vb2_queue_init(&sur40->queue);
744 	if (error)
745 		goto err_unreg_v4l2;
746 
747 	sur40->pix_fmt = sur40_pix_format[0];
748 	sur40->vdev = sur40_video_device;
749 	sur40->vdev.v4l2_dev = &sur40->v4l2;
750 	sur40->vdev.lock = &sur40->lock;
751 	sur40->vdev.queue = &sur40->queue;
752 	video_set_drvdata(&sur40->vdev, sur40);
753 
754 	/* initialize the control handler for 4 controls */
755 	v4l2_ctrl_handler_init(&sur40->hdl, 4);
756 	sur40->v4l2.ctrl_handler = &sur40->hdl;
757 	sur40->vsvideo = (SUR40_CONTRAST_DEF << 4) | SUR40_GAIN_DEF;
758 
759 	v4l2_ctrl_new_std(&sur40->hdl, &sur40_ctrl_ops, V4L2_CID_BRIGHTNESS,
760 	  SUR40_BRIGHTNESS_MIN, SUR40_BRIGHTNESS_MAX, 1, clamp(brightness,
761 	  (uint)SUR40_BRIGHTNESS_MIN, (uint)SUR40_BRIGHTNESS_MAX));
762 
763 	v4l2_ctrl_new_std(&sur40->hdl, &sur40_ctrl_ops, V4L2_CID_CONTRAST,
764 	  SUR40_CONTRAST_MIN, SUR40_CONTRAST_MAX, 1, clamp(contrast,
765 	  (uint)SUR40_CONTRAST_MIN, (uint)SUR40_CONTRAST_MAX));
766 
767 	v4l2_ctrl_new_std(&sur40->hdl, &sur40_ctrl_ops, V4L2_CID_GAIN,
768 	  SUR40_GAIN_MIN, SUR40_GAIN_MAX, 1, clamp(gain,
769 	  (uint)SUR40_GAIN_MIN, (uint)SUR40_GAIN_MAX));
770 
771 	v4l2_ctrl_new_std(&sur40->hdl, &sur40_ctrl_ops,
772 	  V4L2_CID_BACKLIGHT_COMPENSATION, SUR40_BACKLIGHT_MIN,
773 	  SUR40_BACKLIGHT_MAX, 1, SUR40_BACKLIGHT_DEF);
774 
775 	v4l2_ctrl_handler_setup(&sur40->hdl);
776 
777 	if (sur40->hdl.error) {
778 		dev_err(&interface->dev,
779 			"Unable to register video controls.");
780 		v4l2_ctrl_handler_free(&sur40->hdl);
781 		goto err_unreg_v4l2;
782 	}
783 
784 	error = video_register_device(&sur40->vdev, VFL_TYPE_TOUCH, -1);
785 	if (error) {
786 		dev_err(&interface->dev,
787 			"Unable to register video subdevice.");
788 		goto err_unreg_video;
789 	}
790 
791 	/* we can register the device now, as it is ready */
792 	usb_set_intfdata(interface, sur40);
793 	dev_dbg(&interface->dev, "%s is now attached\n", DRIVER_DESC);
794 
795 	return 0;
796 
797 err_unreg_video:
798 	video_unregister_device(&sur40->vdev);
799 err_unreg_v4l2:
800 	v4l2_device_unregister(&sur40->v4l2);
801 err_free_buffer:
802 	kfree(sur40->bulk_in_buffer);
803 err_free_polldev:
804 	input_free_polled_device(sur40->input);
805 err_free_dev:
806 	kfree(sur40);
807 
808 	return error;
809 }
810 
811 /* Unregister device & clean up. */
812 static void sur40_disconnect(struct usb_interface *interface)
813 {
814 	struct sur40_state *sur40 = usb_get_intfdata(interface);
815 
816 	v4l2_ctrl_handler_free(&sur40->hdl);
817 	video_unregister_device(&sur40->vdev);
818 	v4l2_device_unregister(&sur40->v4l2);
819 
820 	input_unregister_polled_device(sur40->input);
821 	input_free_polled_device(sur40->input);
822 	kfree(sur40->bulk_in_buffer);
823 	kfree(sur40);
824 
825 	usb_set_intfdata(interface, NULL);
826 	dev_dbg(&interface->dev, "%s is now disconnected\n", DRIVER_DESC);
827 }
828 
829 /*
830  * Setup the constraints of the queue: besides setting the number of planes
831  * per buffer and the size and allocation context of each plane, it also
832  * checks if sufficient buffers have been allocated. Usually 3 is a good
833  * minimum number: many DMA engines need a minimum of 2 buffers in the
834  * queue and you need to have another available for userspace processing.
835  */
836 static int sur40_queue_setup(struct vb2_queue *q,
837 		       unsigned int *nbuffers, unsigned int *nplanes,
838 		       unsigned int sizes[], struct device *alloc_devs[])
839 {
840 	struct sur40_state *sur40 = vb2_get_drv_priv(q);
841 
842 	if (q->num_buffers + *nbuffers < 3)
843 		*nbuffers = 3 - q->num_buffers;
844 
845 	if (*nplanes)
846 		return sizes[0] < sur40->pix_fmt.sizeimage ? -EINVAL : 0;
847 
848 	*nplanes = 1;
849 	sizes[0] = sur40->pix_fmt.sizeimage;
850 
851 	return 0;
852 }
853 
854 /*
855  * Prepare the buffer for queueing to the DMA engine: check and set the
856  * payload size.
857  */
858 static int sur40_buffer_prepare(struct vb2_buffer *vb)
859 {
860 	struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
861 	unsigned long size = sur40->pix_fmt.sizeimage;
862 
863 	if (vb2_plane_size(vb, 0) < size) {
864 		dev_err(&sur40->usbdev->dev, "buffer too small (%lu < %lu)\n",
865 			 vb2_plane_size(vb, 0), size);
866 		return -EINVAL;
867 	}
868 
869 	vb2_set_plane_payload(vb, 0, size);
870 	return 0;
871 }
872 
873 /*
874  * Queue this buffer to the DMA engine.
875  */
876 static void sur40_buffer_queue(struct vb2_buffer *vb)
877 {
878 	struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
879 	struct sur40_buffer *buf = (struct sur40_buffer *)vb;
880 
881 	spin_lock(&sur40->qlock);
882 	list_add_tail(&buf->list, &sur40->buf_list);
883 	spin_unlock(&sur40->qlock);
884 }
885 
886 static void return_all_buffers(struct sur40_state *sur40,
887 			       enum vb2_buffer_state state)
888 {
889 	struct sur40_buffer *buf, *node;
890 
891 	spin_lock(&sur40->qlock);
892 	list_for_each_entry_safe(buf, node, &sur40->buf_list, list) {
893 		vb2_buffer_done(&buf->vb.vb2_buf, state);
894 		list_del(&buf->list);
895 	}
896 	spin_unlock(&sur40->qlock);
897 }
898 
899 /*
900  * Start streaming. First check if the minimum number of buffers have been
901  * queued. If not, then return -ENOBUFS and the vb2 framework will call
902  * this function again the next time a buffer has been queued until enough
903  * buffers are available to actually start the DMA engine.
904  */
905 static int sur40_start_streaming(struct vb2_queue *vq, unsigned int count)
906 {
907 	struct sur40_state *sur40 = vb2_get_drv_priv(vq);
908 
909 	sur40->sequence = 0;
910 	return 0;
911 }
912 
913 /*
914  * Stop the DMA engine. Any remaining buffers in the DMA queue are dequeued
915  * and passed on to the vb2 framework marked as STATE_ERROR.
916  */
917 static void sur40_stop_streaming(struct vb2_queue *vq)
918 {
919 	struct sur40_state *sur40 = vb2_get_drv_priv(vq);
920 	vb2_wait_for_all_buffers(vq);
921 	sur40->sequence = -1;
922 
923 	/* Release all active buffers */
924 	return_all_buffers(sur40, VB2_BUF_STATE_ERROR);
925 }
926 
927 /* V4L ioctl */
928 static int sur40_vidioc_querycap(struct file *file, void *priv,
929 				 struct v4l2_capability *cap)
930 {
931 	struct sur40_state *sur40 = video_drvdata(file);
932 
933 	strlcpy(cap->driver, DRIVER_SHORT, sizeof(cap->driver));
934 	strlcpy(cap->card, DRIVER_LONG, sizeof(cap->card));
935 	usb_make_path(sur40->usbdev, cap->bus_info, sizeof(cap->bus_info));
936 	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_TOUCH |
937 		V4L2_CAP_READWRITE |
938 		V4L2_CAP_STREAMING;
939 	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
940 	return 0;
941 }
942 
943 static int sur40_vidioc_enum_input(struct file *file, void *priv,
944 				   struct v4l2_input *i)
945 {
946 	if (i->index != 0)
947 		return -EINVAL;
948 	i->type = V4L2_INPUT_TYPE_TOUCH;
949 	i->std = V4L2_STD_UNKNOWN;
950 	strlcpy(i->name, "In-Cell Sensor", sizeof(i->name));
951 	i->capabilities = 0;
952 	return 0;
953 }
954 
955 static int sur40_vidioc_s_input(struct file *file, void *priv, unsigned int i)
956 {
957 	return (i == 0) ? 0 : -EINVAL;
958 }
959 
960 static int sur40_vidioc_g_input(struct file *file, void *priv, unsigned int *i)
961 {
962 	*i = 0;
963 	return 0;
964 }
965 
966 static int sur40_vidioc_try_fmt(struct file *file, void *priv,
967 			    struct v4l2_format *f)
968 {
969 	switch (f->fmt.pix.pixelformat) {
970 	case V4L2_PIX_FMT_GREY:
971 		f->fmt.pix = sur40_pix_format[1];
972 		break;
973 
974 	default:
975 		f->fmt.pix = sur40_pix_format[0];
976 		break;
977 	}
978 
979 	return 0;
980 }
981 
982 static int sur40_vidioc_s_fmt(struct file *file, void *priv,
983 			    struct v4l2_format *f)
984 {
985 	struct sur40_state *sur40 = video_drvdata(file);
986 
987 	switch (f->fmt.pix.pixelformat) {
988 	case V4L2_PIX_FMT_GREY:
989 		sur40->pix_fmt = sur40_pix_format[1];
990 		break;
991 
992 	default:
993 		sur40->pix_fmt = sur40_pix_format[0];
994 		break;
995 	}
996 
997 	f->fmt.pix = sur40->pix_fmt;
998 	return 0;
999 }
1000 
1001 static int sur40_vidioc_g_fmt(struct file *file, void *priv,
1002 			    struct v4l2_format *f)
1003 {
1004 	struct sur40_state *sur40 = video_drvdata(file);
1005 
1006 	f->fmt.pix = sur40->pix_fmt;
1007 	return 0;
1008 }
1009 
1010 static int sur40_s_ctrl(struct v4l2_ctrl *ctrl)
1011 {
1012 	struct sur40_state *sur40  = container_of(ctrl->handler,
1013 	  struct sur40_state, hdl);
1014 	u8 value = sur40->vsvideo;
1015 
1016 	switch (ctrl->id) {
1017 	case V4L2_CID_BRIGHTNESS:
1018 		sur40_set_irlevel(sur40, ctrl->val);
1019 		break;
1020 	case V4L2_CID_CONTRAST:
1021 		value = (value & 0x0f) | (ctrl->val << 4);
1022 		sur40_set_vsvideo(sur40, value);
1023 		break;
1024 	case V4L2_CID_GAIN:
1025 		value = (value & 0xf0) | (ctrl->val);
1026 		sur40_set_vsvideo(sur40, value);
1027 		break;
1028 	case V4L2_CID_BACKLIGHT_COMPENSATION:
1029 		sur40_set_preprocessor(sur40, ctrl->val);
1030 		break;
1031 	}
1032 	return 0;
1033 }
1034 
1035 static int sur40_ioctl_parm(struct file *file, void *priv,
1036 			    struct v4l2_streamparm *p)
1037 {
1038 	if (p->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1039 		return -EINVAL;
1040 
1041 	p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
1042 	p->parm.capture.timeperframe.numerator = 1;
1043 	p->parm.capture.timeperframe.denominator = 60;
1044 	p->parm.capture.readbuffers = 3;
1045 	return 0;
1046 }
1047 
1048 static int sur40_vidioc_enum_fmt(struct file *file, void *priv,
1049 				 struct v4l2_fmtdesc *f)
1050 {
1051 	if (f->index >= ARRAY_SIZE(sur40_pix_format))
1052 		return -EINVAL;
1053 
1054 	f->pixelformat = sur40_pix_format[f->index].pixelformat;
1055 	f->flags = 0;
1056 	return 0;
1057 }
1058 
1059 static int sur40_vidioc_enum_framesizes(struct file *file, void *priv,
1060 					struct v4l2_frmsizeenum *f)
1061 {
1062 	struct sur40_state *sur40 = video_drvdata(file);
1063 
1064 	if ((f->index != 0) || ((f->pixel_format != V4L2_TCH_FMT_TU08)
1065 		&& (f->pixel_format != V4L2_PIX_FMT_GREY)))
1066 		return -EINVAL;
1067 
1068 	f->type = V4L2_FRMSIZE_TYPE_DISCRETE;
1069 	f->discrete.width  = sur40->pix_fmt.width;
1070 	f->discrete.height = sur40->pix_fmt.height;
1071 	return 0;
1072 }
1073 
1074 static int sur40_vidioc_enum_frameintervals(struct file *file, void *priv,
1075 					    struct v4l2_frmivalenum *f)
1076 {
1077 	struct sur40_state *sur40 = video_drvdata(file);
1078 
1079 	if ((f->index > 0) || ((f->pixel_format != V4L2_TCH_FMT_TU08)
1080 		&& (f->pixel_format != V4L2_PIX_FMT_GREY))
1081 		|| (f->width  != sur40->pix_fmt.width)
1082 		|| (f->height != sur40->pix_fmt.height))
1083 		return -EINVAL;
1084 
1085 	f->type = V4L2_FRMIVAL_TYPE_DISCRETE;
1086 	f->discrete.denominator  = 60;
1087 	f->discrete.numerator = 1;
1088 	return 0;
1089 }
1090 
1091 
1092 static const struct usb_device_id sur40_table[] = {
1093 	{ USB_DEVICE(ID_MICROSOFT, ID_SUR40) },  /* Samsung SUR40 */
1094 	{ }                                      /* terminating null entry */
1095 };
1096 MODULE_DEVICE_TABLE(usb, sur40_table);
1097 
1098 /* V4L2 structures */
1099 static const struct vb2_ops sur40_queue_ops = {
1100 	.queue_setup		= sur40_queue_setup,
1101 	.buf_prepare		= sur40_buffer_prepare,
1102 	.buf_queue		= sur40_buffer_queue,
1103 	.start_streaming	= sur40_start_streaming,
1104 	.stop_streaming		= sur40_stop_streaming,
1105 	.wait_prepare		= vb2_ops_wait_prepare,
1106 	.wait_finish		= vb2_ops_wait_finish,
1107 };
1108 
1109 static const struct vb2_queue sur40_queue = {
1110 	.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
1111 	/*
1112 	 * VB2_USERPTR in currently not enabled: passing a user pointer to
1113 	 * dma-sg will result in segment sizes that are not a multiple of
1114 	 * 512 bytes, which is required by the host controller.
1115 	*/
1116 	.io_modes = VB2_MMAP | VB2_READ | VB2_DMABUF,
1117 	.buf_struct_size = sizeof(struct sur40_buffer),
1118 	.ops = &sur40_queue_ops,
1119 	.mem_ops = &vb2_dma_sg_memops,
1120 	.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC,
1121 	.min_buffers_needed = 3,
1122 };
1123 
1124 static const struct v4l2_file_operations sur40_video_fops = {
1125 	.owner = THIS_MODULE,
1126 	.open = v4l2_fh_open,
1127 	.release = vb2_fop_release,
1128 	.unlocked_ioctl = video_ioctl2,
1129 	.read = vb2_fop_read,
1130 	.mmap = vb2_fop_mmap,
1131 	.poll = vb2_fop_poll,
1132 };
1133 
1134 static const struct v4l2_ioctl_ops sur40_video_ioctl_ops = {
1135 
1136 	.vidioc_querycap	= sur40_vidioc_querycap,
1137 
1138 	.vidioc_enum_fmt_vid_cap = sur40_vidioc_enum_fmt,
1139 	.vidioc_try_fmt_vid_cap	= sur40_vidioc_try_fmt,
1140 	.vidioc_s_fmt_vid_cap	= sur40_vidioc_s_fmt,
1141 	.vidioc_g_fmt_vid_cap	= sur40_vidioc_g_fmt,
1142 
1143 	.vidioc_enum_framesizes = sur40_vidioc_enum_framesizes,
1144 	.vidioc_enum_frameintervals = sur40_vidioc_enum_frameintervals,
1145 
1146 	.vidioc_g_parm = sur40_ioctl_parm,
1147 	.vidioc_s_parm = sur40_ioctl_parm,
1148 
1149 	.vidioc_enum_input	= sur40_vidioc_enum_input,
1150 	.vidioc_g_input		= sur40_vidioc_g_input,
1151 	.vidioc_s_input		= sur40_vidioc_s_input,
1152 
1153 	.vidioc_reqbufs		= vb2_ioctl_reqbufs,
1154 	.vidioc_create_bufs	= vb2_ioctl_create_bufs,
1155 	.vidioc_querybuf	= vb2_ioctl_querybuf,
1156 	.vidioc_qbuf		= vb2_ioctl_qbuf,
1157 	.vidioc_dqbuf		= vb2_ioctl_dqbuf,
1158 	.vidioc_expbuf		= vb2_ioctl_expbuf,
1159 
1160 	.vidioc_streamon	= vb2_ioctl_streamon,
1161 	.vidioc_streamoff	= vb2_ioctl_streamoff,
1162 };
1163 
1164 static const struct video_device sur40_video_device = {
1165 	.name = DRIVER_LONG,
1166 	.fops = &sur40_video_fops,
1167 	.ioctl_ops = &sur40_video_ioctl_ops,
1168 	.release = video_device_release_empty,
1169 };
1170 
1171 /* USB-specific object needed to register this driver with the USB subsystem. */
1172 static struct usb_driver sur40_driver = {
1173 	.name = DRIVER_SHORT,
1174 	.probe = sur40_probe,
1175 	.disconnect = sur40_disconnect,
1176 	.id_table = sur40_table,
1177 };
1178 
1179 module_usb_driver(sur40_driver);
1180 
1181 MODULE_AUTHOR(DRIVER_AUTHOR);
1182 MODULE_DESCRIPTION(DRIVER_DESC);
1183 MODULE_LICENSE("GPL");
1184