xref: /linux/drivers/input/touchscreen/sur40.c (revision 335abaea7a27b8a2dfb1ae4573f25019b5d6f68e)
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/videobuf2-v4l2.h>
42 #include <media/videobuf2-dma-sg.h>
43 
44 /* read 512 bytes from endpoint 0x86 -> get header + blobs */
45 struct sur40_header {
46 
47 	__le16 type;       /* always 0x0001 */
48 	__le16 count;      /* count of blobs (if 0: continue prev. packet) */
49 
50 	__le32 packet_id;  /* unique ID for all packets in one frame */
51 
52 	__le32 timestamp;  /* milliseconds (inc. by 16 or 17 each frame) */
53 	__le32 unknown;    /* "epoch?" always 02/03 00 00 00 */
54 
55 } __packed;
56 
57 struct sur40_blob {
58 
59 	__le16 blob_id;
60 
61 	u8 action;         /* 0x02 = enter/exit, 0x03 = update (?) */
62 	u8 type;           /* bitmask (0x01 blob,  0x02 touch, 0x04 tag) */
63 
64 	__le16 bb_pos_x;   /* upper left corner of bounding box */
65 	__le16 bb_pos_y;
66 
67 	__le16 bb_size_x;  /* size of bounding box */
68 	__le16 bb_size_y;
69 
70 	__le16 pos_x;      /* finger tip position */
71 	__le16 pos_y;
72 
73 	__le16 ctr_x;      /* centroid position */
74 	__le16 ctr_y;
75 
76 	__le16 axis_x;     /* somehow related to major/minor axis, mostly: */
77 	__le16 axis_y;     /* axis_x == bb_size_y && axis_y == bb_size_x */
78 
79 	__le32 angle;      /* orientation in radians relative to x axis -
80 	                      actually an IEEE754 float, don't use in kernel */
81 
82 	__le32 area;       /* size in pixels/pressure (?) */
83 
84 	u8 padding[32];
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 static const struct v4l2_pix_format sur40_pix_format[] = {
150 	{
151 		.pixelformat = V4L2_TCH_FMT_TU08,
152 		.width  = SENSOR_RES_X / 2,
153 		.height = SENSOR_RES_Y / 2,
154 		.field = V4L2_FIELD_NONE,
155 		.colorspace = V4L2_COLORSPACE_SRGB,
156 		.bytesperline = SENSOR_RES_X / 2,
157 		.sizeimage = (SENSOR_RES_X/2) * (SENSOR_RES_Y/2),
158 	},
159 	{
160 		.pixelformat = V4L2_PIX_FMT_GREY,
161 		.width  = SENSOR_RES_X / 2,
162 		.height = SENSOR_RES_Y / 2,
163 		.field = V4L2_FIELD_NONE,
164 		.colorspace = V4L2_COLORSPACE_SRGB,
165 		.bytesperline = SENSOR_RES_X / 2,
166 		.sizeimage = (SENSOR_RES_X/2) * (SENSOR_RES_Y/2),
167 	}
168 };
169 
170 /* master device state */
171 struct sur40_state {
172 
173 	struct usb_device *usbdev;
174 	struct device *dev;
175 	struct input_polled_dev *input;
176 
177 	struct v4l2_device v4l2;
178 	struct video_device vdev;
179 	struct mutex lock;
180 	struct v4l2_pix_format pix_fmt;
181 
182 	struct vb2_queue queue;
183 	struct list_head buf_list;
184 	spinlock_t qlock;
185 	int sequence;
186 
187 	struct sur40_data *bulk_in_buffer;
188 	size_t bulk_in_size;
189 	u8 bulk_in_epaddr;
190 
191 	char phys[64];
192 };
193 
194 struct sur40_buffer {
195 	struct vb2_v4l2_buffer vb;
196 	struct list_head list;
197 };
198 
199 /* forward declarations */
200 static const struct video_device sur40_video_device;
201 static const struct vb2_queue sur40_queue;
202 static void sur40_process_video(struct sur40_state *sur40);
203 
204 /*
205  * Note: an earlier, non-public version of this driver used USB_RECIP_ENDPOINT
206  * here by mistake which is very likely to have corrupted the firmware EEPROM
207  * on two separate SUR40 devices. Thanks to Alan Stern who spotted this bug.
208  * Should you ever run into a similar problem, the background story to this
209  * incident and instructions on how to fix the corrupted EEPROM are available
210  * at https://floe.butterbrot.org/matrix/hacking/surface/brick.html
211 */
212 
213 /* command wrapper */
214 static int sur40_command(struct sur40_state *dev,
215 			 u8 command, u16 index, void *buffer, u16 size)
216 {
217 	return usb_control_msg(dev->usbdev, usb_rcvctrlpipe(dev->usbdev, 0),
218 			       command,
219 			       USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
220 			       0x00, index, buffer, size, 1000);
221 }
222 
223 /* Initialization routine, called from sur40_open */
224 static int sur40_init(struct sur40_state *dev)
225 {
226 	int result;
227 	u8 *buffer;
228 
229 	buffer = kmalloc(24, GFP_KERNEL);
230 	if (!buffer) {
231 		result = -ENOMEM;
232 		goto error;
233 	}
234 
235 	/* stupidly replay the original MS driver init sequence */
236 	result = sur40_command(dev, SUR40_GET_VERSION, 0x00, buffer, 12);
237 	if (result < 0)
238 		goto error;
239 
240 	result = sur40_command(dev, SUR40_GET_VERSION, 0x01, buffer, 12);
241 	if (result < 0)
242 		goto error;
243 
244 	result = sur40_command(dev, SUR40_GET_VERSION, 0x02, buffer, 12);
245 	if (result < 0)
246 		goto error;
247 
248 	result = sur40_command(dev, SUR40_SENSOR_CAPS, 0x00, buffer, 24);
249 	if (result < 0)
250 		goto error;
251 
252 	result = sur40_command(dev, SUR40_ACCEL_CAPS, 0x00, buffer, 5);
253 	if (result < 0)
254 		goto error;
255 
256 	result = sur40_command(dev, SUR40_GET_VERSION, 0x03, buffer, 12);
257 
258 	/*
259 	 * Discard the result buffer - no known data inside except
260 	 * some version strings, maybe extract these sometime...
261 	 */
262 error:
263 	kfree(buffer);
264 	return result;
265 }
266 
267 /*
268  * Callback routines from input_polled_dev
269  */
270 
271 /* Enable the device, polling will now start. */
272 static void sur40_open(struct input_polled_dev *polldev)
273 {
274 	struct sur40_state *sur40 = polldev->private;
275 
276 	dev_dbg(sur40->dev, "open\n");
277 	sur40_init(sur40);
278 }
279 
280 /* Disable device, polling has stopped. */
281 static void sur40_close(struct input_polled_dev *polldev)
282 {
283 	struct sur40_state *sur40 = polldev->private;
284 
285 	dev_dbg(sur40->dev, "close\n");
286 	/*
287 	 * There is no known way to stop the device, so we simply
288 	 * stop polling.
289 	 */
290 }
291 
292 /*
293  * This function is called when a whole contact has been processed,
294  * so that it can assign it to a slot and store the data there.
295  */
296 static void sur40_report_blob(struct sur40_blob *blob, struct input_dev *input)
297 {
298 	int wide, major, minor;
299 
300 	int bb_size_x = le16_to_cpu(blob->bb_size_x);
301 	int bb_size_y = le16_to_cpu(blob->bb_size_y);
302 
303 	int pos_x = le16_to_cpu(blob->pos_x);
304 	int pos_y = le16_to_cpu(blob->pos_y);
305 
306 	int ctr_x = le16_to_cpu(blob->ctr_x);
307 	int ctr_y = le16_to_cpu(blob->ctr_y);
308 
309 	int slotnum = input_mt_get_slot_by_key(input, blob->blob_id);
310 	if (slotnum < 0 || slotnum >= MAX_CONTACTS)
311 		return;
312 
313 	input_mt_slot(input, slotnum);
314 	input_mt_report_slot_state(input, MT_TOOL_FINGER, 1);
315 	wide = (bb_size_x > bb_size_y);
316 	major = max(bb_size_x, bb_size_y);
317 	minor = min(bb_size_x, bb_size_y);
318 
319 	input_report_abs(input, ABS_MT_POSITION_X, pos_x);
320 	input_report_abs(input, ABS_MT_POSITION_Y, pos_y);
321 	input_report_abs(input, ABS_MT_TOOL_X, ctr_x);
322 	input_report_abs(input, ABS_MT_TOOL_Y, ctr_y);
323 
324 	/* TODO: use a better orientation measure */
325 	input_report_abs(input, ABS_MT_ORIENTATION, wide);
326 	input_report_abs(input, ABS_MT_TOUCH_MAJOR, major);
327 	input_report_abs(input, ABS_MT_TOUCH_MINOR, minor);
328 }
329 
330 /* core function: poll for new input data */
331 static void sur40_poll(struct input_polled_dev *polldev)
332 {
333 	struct sur40_state *sur40 = polldev->private;
334 	struct input_dev *input = polldev->input;
335 	int result, bulk_read, need_blobs, packet_blobs, i;
336 	u32 uninitialized_var(packet_id);
337 
338 	struct sur40_header *header = &sur40->bulk_in_buffer->header;
339 	struct sur40_blob *inblob = &sur40->bulk_in_buffer->blobs[0];
340 
341 	dev_dbg(sur40->dev, "poll\n");
342 
343 	need_blobs = -1;
344 
345 	do {
346 
347 		/* perform a blocking bulk read to get data from the device */
348 		result = usb_bulk_msg(sur40->usbdev,
349 			usb_rcvbulkpipe(sur40->usbdev, sur40->bulk_in_epaddr),
350 			sur40->bulk_in_buffer, sur40->bulk_in_size,
351 			&bulk_read, 1000);
352 
353 		dev_dbg(sur40->dev, "received %d bytes\n", bulk_read);
354 
355 		if (result < 0) {
356 			dev_err(sur40->dev, "error in usb_bulk_read\n");
357 			return;
358 		}
359 
360 		result = bulk_read - sizeof(struct sur40_header);
361 
362 		if (result % sizeof(struct sur40_blob) != 0) {
363 			dev_err(sur40->dev, "transfer size mismatch\n");
364 			return;
365 		}
366 
367 		/* first packet? */
368 		if (need_blobs == -1) {
369 			need_blobs = le16_to_cpu(header->count);
370 			dev_dbg(sur40->dev, "need %d blobs\n", need_blobs);
371 			packet_id = le32_to_cpu(header->packet_id);
372 		}
373 
374 		/*
375 		 * Sanity check. when video data is also being retrieved, the
376 		 * packet ID will usually increase in the middle of a series
377 		 * instead of at the end. However, the data is still consistent,
378 		 * so the packet ID is probably just valid for the first packet
379 		 * in a series.
380 
381 		if (packet_id != le32_to_cpu(header->packet_id))
382 			dev_dbg(sur40->dev, "packet ID mismatch\n");
383 		 */
384 
385 		packet_blobs = result / sizeof(struct sur40_blob);
386 		dev_dbg(sur40->dev, "received %d blobs\n", packet_blobs);
387 
388 		/* packets always contain at least 4 blobs, even if empty */
389 		if (packet_blobs > need_blobs)
390 			packet_blobs = need_blobs;
391 
392 		for (i = 0; i < packet_blobs; i++) {
393 			need_blobs--;
394 			dev_dbg(sur40->dev, "processing blob\n");
395 			sur40_report_blob(&(inblob[i]), input);
396 		}
397 
398 	} while (need_blobs > 0);
399 
400 	input_mt_sync_frame(input);
401 	input_sync(input);
402 
403 	sur40_process_video(sur40);
404 }
405 
406 /* deal with video data */
407 static void sur40_process_video(struct sur40_state *sur40)
408 {
409 
410 	struct sur40_image_header *img = (void *)(sur40->bulk_in_buffer);
411 	struct sur40_buffer *new_buf;
412 	struct usb_sg_request sgr;
413 	struct sg_table *sgt;
414 	int result, bulk_read;
415 
416 	if (!vb2_start_streaming_called(&sur40->queue))
417 		return;
418 
419 	/* get a new buffer from the list */
420 	spin_lock(&sur40->qlock);
421 	if (list_empty(&sur40->buf_list)) {
422 		dev_dbg(sur40->dev, "buffer queue empty\n");
423 		spin_unlock(&sur40->qlock);
424 		return;
425 	}
426 	new_buf = list_entry(sur40->buf_list.next, struct sur40_buffer, list);
427 	list_del(&new_buf->list);
428 	spin_unlock(&sur40->qlock);
429 
430 	dev_dbg(sur40->dev, "buffer acquired\n");
431 
432 	/* retrieve data via bulk read */
433 	result = usb_bulk_msg(sur40->usbdev,
434 			usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT),
435 			sur40->bulk_in_buffer, sur40->bulk_in_size,
436 			&bulk_read, 1000);
437 
438 	if (result < 0) {
439 		dev_err(sur40->dev, "error in usb_bulk_read\n");
440 		goto err_poll;
441 	}
442 
443 	if (bulk_read != sizeof(struct sur40_image_header)) {
444 		dev_err(sur40->dev, "received %d bytes (%zd expected)\n",
445 			bulk_read, sizeof(struct sur40_image_header));
446 		goto err_poll;
447 	}
448 
449 	if (le32_to_cpu(img->magic) != VIDEO_HEADER_MAGIC) {
450 		dev_err(sur40->dev, "image magic mismatch\n");
451 		goto err_poll;
452 	}
453 
454 	if (le32_to_cpu(img->size) != sur40->pix_fmt.sizeimage) {
455 		dev_err(sur40->dev, "image size mismatch\n");
456 		goto err_poll;
457 	}
458 
459 	dev_dbg(sur40->dev, "header acquired\n");
460 
461 	sgt = vb2_dma_sg_plane_desc(&new_buf->vb.vb2_buf, 0);
462 
463 	result = usb_sg_init(&sgr, sur40->usbdev,
464 		usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT), 0,
465 		sgt->sgl, sgt->nents, sur40->pix_fmt.sizeimage, 0);
466 	if (result < 0) {
467 		dev_err(sur40->dev, "error %d in usb_sg_init\n", result);
468 		goto err_poll;
469 	}
470 
471 	usb_sg_wait(&sgr);
472 	if (sgr.status < 0) {
473 		dev_err(sur40->dev, "error %d in usb_sg_wait\n", sgr.status);
474 		goto err_poll;
475 	}
476 
477 	dev_dbg(sur40->dev, "image acquired\n");
478 
479 	/* return error if streaming was stopped in the meantime */
480 	if (sur40->sequence == -1)
481 		return;
482 
483 	/* mark as finished */
484 	new_buf->vb.vb2_buf.timestamp = ktime_get_ns();
485 	new_buf->vb.sequence = sur40->sequence++;
486 	new_buf->vb.field = V4L2_FIELD_NONE;
487 	vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
488 	dev_dbg(sur40->dev, "buffer marked done\n");
489 	return;
490 
491 err_poll:
492 	vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
493 }
494 
495 /* Initialize input device parameters. */
496 static void sur40_input_setup(struct input_dev *input_dev)
497 {
498 	__set_bit(EV_KEY, input_dev->evbit);
499 	__set_bit(EV_ABS, input_dev->evbit);
500 
501 	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
502 			     0, SENSOR_RES_X, 0, 0);
503 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
504 			     0, SENSOR_RES_Y, 0, 0);
505 
506 	input_set_abs_params(input_dev, ABS_MT_TOOL_X,
507 			     0, SENSOR_RES_X, 0, 0);
508 	input_set_abs_params(input_dev, ABS_MT_TOOL_Y,
509 			     0, SENSOR_RES_Y, 0, 0);
510 
511 	/* max value unknown, but major/minor axis
512 	 * can never be larger than screen */
513 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
514 			     0, SENSOR_RES_X, 0, 0);
515 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR,
516 			     0, SENSOR_RES_Y, 0, 0);
517 
518 	input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
519 
520 	input_mt_init_slots(input_dev, MAX_CONTACTS,
521 			    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
522 }
523 
524 /* Check candidate USB interface. */
525 static int sur40_probe(struct usb_interface *interface,
526 		       const struct usb_device_id *id)
527 {
528 	struct usb_device *usbdev = interface_to_usbdev(interface);
529 	struct sur40_state *sur40;
530 	struct usb_host_interface *iface_desc;
531 	struct usb_endpoint_descriptor *endpoint;
532 	struct input_polled_dev *poll_dev;
533 	int error;
534 
535 	/* Check if we really have the right interface. */
536 	iface_desc = &interface->altsetting[0];
537 	if (iface_desc->desc.bInterfaceClass != 0xFF)
538 		return -ENODEV;
539 
540 	if (iface_desc->desc.bNumEndpoints < 5)
541 		return -ENODEV;
542 
543 	/* Use endpoint #4 (0x86). */
544 	endpoint = &iface_desc->endpoint[4].desc;
545 	if (endpoint->bEndpointAddress != TOUCH_ENDPOINT)
546 		return -ENODEV;
547 
548 	/* Allocate memory for our device state and initialize it. */
549 	sur40 = kzalloc(sizeof(struct sur40_state), GFP_KERNEL);
550 	if (!sur40)
551 		return -ENOMEM;
552 
553 	poll_dev = input_allocate_polled_device();
554 	if (!poll_dev) {
555 		error = -ENOMEM;
556 		goto err_free_dev;
557 	}
558 
559 	/* initialize locks/lists */
560 	INIT_LIST_HEAD(&sur40->buf_list);
561 	spin_lock_init(&sur40->qlock);
562 	mutex_init(&sur40->lock);
563 
564 	/* Set up polled input device control structure */
565 	poll_dev->private = sur40;
566 	poll_dev->poll_interval = POLL_INTERVAL;
567 	poll_dev->open = sur40_open;
568 	poll_dev->poll = sur40_poll;
569 	poll_dev->close = sur40_close;
570 
571 	/* Set up regular input device structure */
572 	sur40_input_setup(poll_dev->input);
573 
574 	poll_dev->input->name = DRIVER_LONG;
575 	usb_to_input_id(usbdev, &poll_dev->input->id);
576 	usb_make_path(usbdev, sur40->phys, sizeof(sur40->phys));
577 	strlcat(sur40->phys, "/input0", sizeof(sur40->phys));
578 	poll_dev->input->phys = sur40->phys;
579 	poll_dev->input->dev.parent = &interface->dev;
580 
581 	sur40->usbdev = usbdev;
582 	sur40->dev = &interface->dev;
583 	sur40->input = poll_dev;
584 
585 	/* use the bulk-in endpoint tested above */
586 	sur40->bulk_in_size = usb_endpoint_maxp(endpoint);
587 	sur40->bulk_in_epaddr = endpoint->bEndpointAddress;
588 	sur40->bulk_in_buffer = kmalloc(sur40->bulk_in_size, GFP_KERNEL);
589 	if (!sur40->bulk_in_buffer) {
590 		dev_err(&interface->dev, "Unable to allocate input buffer.");
591 		error = -ENOMEM;
592 		goto err_free_polldev;
593 	}
594 
595 	/* register the polled input device */
596 	error = input_register_polled_device(poll_dev);
597 	if (error) {
598 		dev_err(&interface->dev,
599 			"Unable to register polled input device.");
600 		goto err_free_buffer;
601 	}
602 
603 	/* register the video master device */
604 	snprintf(sur40->v4l2.name, sizeof(sur40->v4l2.name), "%s", DRIVER_LONG);
605 	error = v4l2_device_register(sur40->dev, &sur40->v4l2);
606 	if (error) {
607 		dev_err(&interface->dev,
608 			"Unable to register video master device.");
609 		goto err_unreg_v4l2;
610 	}
611 
612 	/* initialize the lock and subdevice */
613 	sur40->queue = sur40_queue;
614 	sur40->queue.drv_priv = sur40;
615 	sur40->queue.lock = &sur40->lock;
616 	sur40->queue.dev = sur40->dev;
617 
618 	/* initialize the queue */
619 	error = vb2_queue_init(&sur40->queue);
620 	if (error)
621 		goto err_unreg_v4l2;
622 
623 	sur40->pix_fmt = sur40_pix_format[0];
624 	sur40->vdev = sur40_video_device;
625 	sur40->vdev.v4l2_dev = &sur40->v4l2;
626 	sur40->vdev.lock = &sur40->lock;
627 	sur40->vdev.queue = &sur40->queue;
628 	video_set_drvdata(&sur40->vdev, sur40);
629 
630 	error = video_register_device(&sur40->vdev, VFL_TYPE_TOUCH, -1);
631 	if (error) {
632 		dev_err(&interface->dev,
633 			"Unable to register video subdevice.");
634 		goto err_unreg_video;
635 	}
636 
637 	/* we can register the device now, as it is ready */
638 	usb_set_intfdata(interface, sur40);
639 	dev_dbg(&interface->dev, "%s is now attached\n", DRIVER_DESC);
640 
641 	return 0;
642 
643 err_unreg_video:
644 	video_unregister_device(&sur40->vdev);
645 err_unreg_v4l2:
646 	v4l2_device_unregister(&sur40->v4l2);
647 err_free_buffer:
648 	kfree(sur40->bulk_in_buffer);
649 err_free_polldev:
650 	input_free_polled_device(sur40->input);
651 err_free_dev:
652 	kfree(sur40);
653 
654 	return error;
655 }
656 
657 /* Unregister device & clean up. */
658 static void sur40_disconnect(struct usb_interface *interface)
659 {
660 	struct sur40_state *sur40 = usb_get_intfdata(interface);
661 
662 	video_unregister_device(&sur40->vdev);
663 	v4l2_device_unregister(&sur40->v4l2);
664 
665 	input_unregister_polled_device(sur40->input);
666 	input_free_polled_device(sur40->input);
667 	kfree(sur40->bulk_in_buffer);
668 	kfree(sur40);
669 
670 	usb_set_intfdata(interface, NULL);
671 	dev_dbg(&interface->dev, "%s is now disconnected\n", DRIVER_DESC);
672 }
673 
674 /*
675  * Setup the constraints of the queue: besides setting the number of planes
676  * per buffer and the size and allocation context of each plane, it also
677  * checks if sufficient buffers have been allocated. Usually 3 is a good
678  * minimum number: many DMA engines need a minimum of 2 buffers in the
679  * queue and you need to have another available for userspace processing.
680  */
681 static int sur40_queue_setup(struct vb2_queue *q,
682 		       unsigned int *nbuffers, unsigned int *nplanes,
683 		       unsigned int sizes[], struct device *alloc_devs[])
684 {
685 	struct sur40_state *sur40 = vb2_get_drv_priv(q);
686 
687 	if (q->num_buffers + *nbuffers < 3)
688 		*nbuffers = 3 - q->num_buffers;
689 
690 	if (*nplanes)
691 		return sizes[0] < sur40->pix_fmt.sizeimage ? -EINVAL : 0;
692 
693 	*nplanes = 1;
694 	sizes[0] = sur40->pix_fmt.sizeimage;
695 
696 	return 0;
697 }
698 
699 /*
700  * Prepare the buffer for queueing to the DMA engine: check and set the
701  * payload size.
702  */
703 static int sur40_buffer_prepare(struct vb2_buffer *vb)
704 {
705 	struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
706 	unsigned long size = sur40->pix_fmt.sizeimage;
707 
708 	if (vb2_plane_size(vb, 0) < size) {
709 		dev_err(&sur40->usbdev->dev, "buffer too small (%lu < %lu)\n",
710 			 vb2_plane_size(vb, 0), size);
711 		return -EINVAL;
712 	}
713 
714 	vb2_set_plane_payload(vb, 0, size);
715 	return 0;
716 }
717 
718 /*
719  * Queue this buffer to the DMA engine.
720  */
721 static void sur40_buffer_queue(struct vb2_buffer *vb)
722 {
723 	struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
724 	struct sur40_buffer *buf = (struct sur40_buffer *)vb;
725 
726 	spin_lock(&sur40->qlock);
727 	list_add_tail(&buf->list, &sur40->buf_list);
728 	spin_unlock(&sur40->qlock);
729 }
730 
731 static void return_all_buffers(struct sur40_state *sur40,
732 			       enum vb2_buffer_state state)
733 {
734 	struct sur40_buffer *buf, *node;
735 
736 	spin_lock(&sur40->qlock);
737 	list_for_each_entry_safe(buf, node, &sur40->buf_list, list) {
738 		vb2_buffer_done(&buf->vb.vb2_buf, state);
739 		list_del(&buf->list);
740 	}
741 	spin_unlock(&sur40->qlock);
742 }
743 
744 /*
745  * Start streaming. First check if the minimum number of buffers have been
746  * queued. If not, then return -ENOBUFS and the vb2 framework will call
747  * this function again the next time a buffer has been queued until enough
748  * buffers are available to actually start the DMA engine.
749  */
750 static int sur40_start_streaming(struct vb2_queue *vq, unsigned int count)
751 {
752 	struct sur40_state *sur40 = vb2_get_drv_priv(vq);
753 
754 	sur40->sequence = 0;
755 	return 0;
756 }
757 
758 /*
759  * Stop the DMA engine. Any remaining buffers in the DMA queue are dequeued
760  * and passed on to the vb2 framework marked as STATE_ERROR.
761  */
762 static void sur40_stop_streaming(struct vb2_queue *vq)
763 {
764 	struct sur40_state *sur40 = vb2_get_drv_priv(vq);
765 	vb2_wait_for_all_buffers(vq);
766 	sur40->sequence = -1;
767 
768 	/* Release all active buffers */
769 	return_all_buffers(sur40, VB2_BUF_STATE_ERROR);
770 }
771 
772 /* V4L ioctl */
773 static int sur40_vidioc_querycap(struct file *file, void *priv,
774 				 struct v4l2_capability *cap)
775 {
776 	struct sur40_state *sur40 = video_drvdata(file);
777 
778 	strlcpy(cap->driver, DRIVER_SHORT, sizeof(cap->driver));
779 	strlcpy(cap->card, DRIVER_LONG, sizeof(cap->card));
780 	usb_make_path(sur40->usbdev, cap->bus_info, sizeof(cap->bus_info));
781 	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_TOUCH |
782 		V4L2_CAP_READWRITE |
783 		V4L2_CAP_STREAMING;
784 	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
785 	return 0;
786 }
787 
788 static int sur40_vidioc_enum_input(struct file *file, void *priv,
789 				   struct v4l2_input *i)
790 {
791 	if (i->index != 0)
792 		return -EINVAL;
793 	i->type = V4L2_INPUT_TYPE_TOUCH;
794 	i->std = V4L2_STD_UNKNOWN;
795 	strlcpy(i->name, "In-Cell Sensor", sizeof(i->name));
796 	i->capabilities = 0;
797 	return 0;
798 }
799 
800 static int sur40_vidioc_s_input(struct file *file, void *priv, unsigned int i)
801 {
802 	return (i == 0) ? 0 : -EINVAL;
803 }
804 
805 static int sur40_vidioc_g_input(struct file *file, void *priv, unsigned int *i)
806 {
807 	*i = 0;
808 	return 0;
809 }
810 
811 static int sur40_vidioc_try_fmt(struct file *file, void *priv,
812 			    struct v4l2_format *f)
813 {
814 	switch (f->fmt.pix.pixelformat) {
815 	case V4L2_PIX_FMT_GREY:
816 		f->fmt.pix = sur40_pix_format[1];
817 		break;
818 
819 	default:
820 		f->fmt.pix = sur40_pix_format[0];
821 		break;
822 	}
823 
824 	return 0;
825 }
826 
827 static int sur40_vidioc_s_fmt(struct file *file, void *priv,
828 			    struct v4l2_format *f)
829 {
830 	struct sur40_state *sur40 = video_drvdata(file);
831 
832 	switch (f->fmt.pix.pixelformat) {
833 	case V4L2_PIX_FMT_GREY:
834 		sur40->pix_fmt = sur40_pix_format[1];
835 		break;
836 
837 	default:
838 		sur40->pix_fmt = sur40_pix_format[0];
839 		break;
840 	}
841 
842 	f->fmt.pix = sur40->pix_fmt;
843 	return 0;
844 }
845 
846 static int sur40_vidioc_g_fmt(struct file *file, void *priv,
847 			    struct v4l2_format *f)
848 {
849 	struct sur40_state *sur40 = video_drvdata(file);
850 
851 	f->fmt.pix = sur40->pix_fmt;
852 	return 0;
853 }
854 
855 static int sur40_ioctl_parm(struct file *file, void *priv,
856 			    struct v4l2_streamparm *p)
857 {
858 	if (p->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
859 		return -EINVAL;
860 
861 	p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
862 	p->parm.capture.timeperframe.numerator = 1;
863 	p->parm.capture.timeperframe.denominator = 60;
864 	p->parm.capture.readbuffers = 3;
865 	return 0;
866 }
867 
868 static int sur40_vidioc_enum_fmt(struct file *file, void *priv,
869 				 struct v4l2_fmtdesc *f)
870 {
871 	if (f->index >= ARRAY_SIZE(sur40_pix_format))
872 		return -EINVAL;
873 
874 	f->pixelformat = sur40_pix_format[f->index].pixelformat;
875 	f->flags = 0;
876 	return 0;
877 }
878 
879 static int sur40_vidioc_enum_framesizes(struct file *file, void *priv,
880 					struct v4l2_frmsizeenum *f)
881 {
882 	struct sur40_state *sur40 = video_drvdata(file);
883 
884 	if ((f->index != 0) || ((f->pixel_format != V4L2_TCH_FMT_TU08)
885 		&& (f->pixel_format != V4L2_PIX_FMT_GREY)))
886 		return -EINVAL;
887 
888 	f->type = V4L2_FRMSIZE_TYPE_DISCRETE;
889 	f->discrete.width  = sur40->pix_fmt.width;
890 	f->discrete.height = sur40->pix_fmt.height;
891 	return 0;
892 }
893 
894 static int sur40_vidioc_enum_frameintervals(struct file *file, void *priv,
895 					    struct v4l2_frmivalenum *f)
896 {
897 	struct sur40_state *sur40 = video_drvdata(file);
898 
899 	if ((f->index > 0) || ((f->pixel_format != V4L2_TCH_FMT_TU08)
900 		&& (f->pixel_format != V4L2_PIX_FMT_GREY))
901 		|| (f->width  != sur40->pix_fmt.width)
902 		|| (f->height != sur40->pix_fmt.height))
903 		return -EINVAL;
904 
905 	f->type = V4L2_FRMIVAL_TYPE_DISCRETE;
906 	f->discrete.denominator  = 60;
907 	f->discrete.numerator = 1;
908 	return 0;
909 }
910 
911 
912 static const struct usb_device_id sur40_table[] = {
913 	{ USB_DEVICE(ID_MICROSOFT, ID_SUR40) },  /* Samsung SUR40 */
914 	{ }                                      /* terminating null entry */
915 };
916 MODULE_DEVICE_TABLE(usb, sur40_table);
917 
918 /* V4L2 structures */
919 static const struct vb2_ops sur40_queue_ops = {
920 	.queue_setup		= sur40_queue_setup,
921 	.buf_prepare		= sur40_buffer_prepare,
922 	.buf_queue		= sur40_buffer_queue,
923 	.start_streaming	= sur40_start_streaming,
924 	.stop_streaming		= sur40_stop_streaming,
925 	.wait_prepare		= vb2_ops_wait_prepare,
926 	.wait_finish		= vb2_ops_wait_finish,
927 };
928 
929 static const struct vb2_queue sur40_queue = {
930 	.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
931 	/*
932 	 * VB2_USERPTR in currently not enabled: passing a user pointer to
933 	 * dma-sg will result in segment sizes that are not a multiple of
934 	 * 512 bytes, which is required by the host controller.
935 	*/
936 	.io_modes = VB2_MMAP | VB2_READ | VB2_DMABUF,
937 	.buf_struct_size = sizeof(struct sur40_buffer),
938 	.ops = &sur40_queue_ops,
939 	.mem_ops = &vb2_dma_sg_memops,
940 	.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC,
941 	.min_buffers_needed = 3,
942 };
943 
944 static const struct v4l2_file_operations sur40_video_fops = {
945 	.owner = THIS_MODULE,
946 	.open = v4l2_fh_open,
947 	.release = vb2_fop_release,
948 	.unlocked_ioctl = video_ioctl2,
949 	.read = vb2_fop_read,
950 	.mmap = vb2_fop_mmap,
951 	.poll = vb2_fop_poll,
952 };
953 
954 static const struct v4l2_ioctl_ops sur40_video_ioctl_ops = {
955 
956 	.vidioc_querycap	= sur40_vidioc_querycap,
957 
958 	.vidioc_enum_fmt_vid_cap = sur40_vidioc_enum_fmt,
959 	.vidioc_try_fmt_vid_cap	= sur40_vidioc_try_fmt,
960 	.vidioc_s_fmt_vid_cap	= sur40_vidioc_s_fmt,
961 	.vidioc_g_fmt_vid_cap	= sur40_vidioc_g_fmt,
962 
963 	.vidioc_enum_framesizes = sur40_vidioc_enum_framesizes,
964 	.vidioc_enum_frameintervals = sur40_vidioc_enum_frameintervals,
965 
966 	.vidioc_g_parm = sur40_ioctl_parm,
967 	.vidioc_s_parm = sur40_ioctl_parm,
968 
969 	.vidioc_enum_input	= sur40_vidioc_enum_input,
970 	.vidioc_g_input		= sur40_vidioc_g_input,
971 	.vidioc_s_input		= sur40_vidioc_s_input,
972 
973 	.vidioc_reqbufs		= vb2_ioctl_reqbufs,
974 	.vidioc_create_bufs	= vb2_ioctl_create_bufs,
975 	.vidioc_querybuf	= vb2_ioctl_querybuf,
976 	.vidioc_qbuf		= vb2_ioctl_qbuf,
977 	.vidioc_dqbuf		= vb2_ioctl_dqbuf,
978 	.vidioc_expbuf		= vb2_ioctl_expbuf,
979 
980 	.vidioc_streamon	= vb2_ioctl_streamon,
981 	.vidioc_streamoff	= vb2_ioctl_streamoff,
982 };
983 
984 static const struct video_device sur40_video_device = {
985 	.name = DRIVER_LONG,
986 	.fops = &sur40_video_fops,
987 	.ioctl_ops = &sur40_video_ioctl_ops,
988 	.release = video_device_release_empty,
989 };
990 
991 /* USB-specific object needed to register this driver with the USB subsystem. */
992 static struct usb_driver sur40_driver = {
993 	.name = DRIVER_SHORT,
994 	.probe = sur40_probe,
995 	.disconnect = sur40_disconnect,
996 	.id_table = sur40_table,
997 };
998 
999 module_usb_driver(sur40_driver);
1000 
1001 MODULE_AUTHOR(DRIVER_AUTHOR);
1002 MODULE_DESCRIPTION(DRIVER_DESC);
1003 MODULE_LICENSE("GPL");
1004