xref: /linux/drivers/input/touchscreen/sur40.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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 unknown;        /* always 0x01 or 0x02 (no idea what this is?) */
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 4
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_UNKNOWN1    0xb3 /*  5 bytes           */
137 #define SUR40_UNKNOWN2    0xc1 /* 24 bytes           */
138 
139 #define SUR40_GET_STATE   0xc5 /*  4 bytes state (?) */
140 #define SUR40_GET_SENSORS 0xb1 /*  8 bytes sensors   */
141 
142 /* master device state */
143 struct sur40_state {
144 
145 	struct usb_device *usbdev;
146 	struct device *dev;
147 	struct input_polled_dev *input;
148 
149 	struct v4l2_device v4l2;
150 	struct video_device vdev;
151 	struct mutex lock;
152 
153 	struct vb2_queue queue;
154 	struct vb2_alloc_ctx *alloc_ctx;
155 	struct list_head buf_list;
156 	spinlock_t qlock;
157 	int sequence;
158 
159 	struct sur40_data *bulk_in_buffer;
160 	size_t bulk_in_size;
161 	u8 bulk_in_epaddr;
162 
163 	char phys[64];
164 };
165 
166 struct sur40_buffer {
167 	struct vb2_v4l2_buffer vb;
168 	struct list_head list;
169 };
170 
171 /* forward declarations */
172 static const struct video_device sur40_video_device;
173 static const struct v4l2_pix_format sur40_video_format;
174 static const struct vb2_queue sur40_queue;
175 static void sur40_process_video(struct sur40_state *sur40);
176 
177 /*
178  * Note: an earlier, non-public version of this driver used USB_RECIP_ENDPOINT
179  * here by mistake which is very likely to have corrupted the firmware EEPROM
180  * on two separate SUR40 devices. Thanks to Alan Stern who spotted this bug.
181  * Should you ever run into a similar problem, the background story to this
182  * incident and instructions on how to fix the corrupted EEPROM are available
183  * at https://floe.butterbrot.org/matrix/hacking/surface/brick.html
184 */
185 
186 /* command wrapper */
187 static int sur40_command(struct sur40_state *dev,
188 			 u8 command, u16 index, void *buffer, u16 size)
189 {
190 	return usb_control_msg(dev->usbdev, usb_rcvctrlpipe(dev->usbdev, 0),
191 			       command,
192 			       USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
193 			       0x00, index, buffer, size, 1000);
194 }
195 
196 /* Initialization routine, called from sur40_open */
197 static int sur40_init(struct sur40_state *dev)
198 {
199 	int result;
200 	u8 buffer[24];
201 
202 	/* stupidly replay the original MS driver init sequence */
203 	result = sur40_command(dev, SUR40_GET_VERSION, 0x00, buffer, 12);
204 	if (result < 0)
205 		return result;
206 
207 	result = sur40_command(dev, SUR40_GET_VERSION, 0x01, buffer, 12);
208 	if (result < 0)
209 		return result;
210 
211 	result = sur40_command(dev, SUR40_GET_VERSION, 0x02, buffer, 12);
212 	if (result < 0)
213 		return result;
214 
215 	result = sur40_command(dev, SUR40_UNKNOWN2,    0x00, buffer, 24);
216 	if (result < 0)
217 		return result;
218 
219 	result = sur40_command(dev, SUR40_UNKNOWN1,    0x00, buffer,  5);
220 	if (result < 0)
221 		return result;
222 
223 	result = sur40_command(dev, SUR40_GET_VERSION, 0x03, buffer, 12);
224 
225 	/*
226 	 * Discard the result buffer - no known data inside except
227 	 * some version strings, maybe extract these sometime...
228 	 */
229 
230 	return result;
231 }
232 
233 /*
234  * Callback routines from input_polled_dev
235  */
236 
237 /* Enable the device, polling will now start. */
238 static void sur40_open(struct input_polled_dev *polldev)
239 {
240 	struct sur40_state *sur40 = polldev->private;
241 
242 	dev_dbg(sur40->dev, "open\n");
243 	sur40_init(sur40);
244 }
245 
246 /* Disable device, polling has stopped. */
247 static void sur40_close(struct input_polled_dev *polldev)
248 {
249 	struct sur40_state *sur40 = polldev->private;
250 
251 	dev_dbg(sur40->dev, "close\n");
252 	/*
253 	 * There is no known way to stop the device, so we simply
254 	 * stop polling.
255 	 */
256 }
257 
258 /*
259  * This function is called when a whole contact has been processed,
260  * so that it can assign it to a slot and store the data there.
261  */
262 static void sur40_report_blob(struct sur40_blob *blob, struct input_dev *input)
263 {
264 	int wide, major, minor;
265 
266 	int bb_size_x = le16_to_cpu(blob->bb_size_x);
267 	int bb_size_y = le16_to_cpu(blob->bb_size_y);
268 
269 	int pos_x = le16_to_cpu(blob->pos_x);
270 	int pos_y = le16_to_cpu(blob->pos_y);
271 
272 	int ctr_x = le16_to_cpu(blob->ctr_x);
273 	int ctr_y = le16_to_cpu(blob->ctr_y);
274 
275 	int slotnum = input_mt_get_slot_by_key(input, blob->blob_id);
276 	if (slotnum < 0 || slotnum >= MAX_CONTACTS)
277 		return;
278 
279 	input_mt_slot(input, slotnum);
280 	input_mt_report_slot_state(input, MT_TOOL_FINGER, 1);
281 	wide = (bb_size_x > bb_size_y);
282 	major = max(bb_size_x, bb_size_y);
283 	minor = min(bb_size_x, bb_size_y);
284 
285 	input_report_abs(input, ABS_MT_POSITION_X, pos_x);
286 	input_report_abs(input, ABS_MT_POSITION_Y, pos_y);
287 	input_report_abs(input, ABS_MT_TOOL_X, ctr_x);
288 	input_report_abs(input, ABS_MT_TOOL_Y, ctr_y);
289 
290 	/* TODO: use a better orientation measure */
291 	input_report_abs(input, ABS_MT_ORIENTATION, wide);
292 	input_report_abs(input, ABS_MT_TOUCH_MAJOR, major);
293 	input_report_abs(input, ABS_MT_TOUCH_MINOR, minor);
294 }
295 
296 /* core function: poll for new input data */
297 static void sur40_poll(struct input_polled_dev *polldev)
298 {
299 	struct sur40_state *sur40 = polldev->private;
300 	struct input_dev *input = polldev->input;
301 	int result, bulk_read, need_blobs, packet_blobs, i;
302 	u32 uninitialized_var(packet_id);
303 
304 	struct sur40_header *header = &sur40->bulk_in_buffer->header;
305 	struct sur40_blob *inblob = &sur40->bulk_in_buffer->blobs[0];
306 
307 	dev_dbg(sur40->dev, "poll\n");
308 
309 	need_blobs = -1;
310 
311 	do {
312 
313 		/* perform a blocking bulk read to get data from the device */
314 		result = usb_bulk_msg(sur40->usbdev,
315 			usb_rcvbulkpipe(sur40->usbdev, sur40->bulk_in_epaddr),
316 			sur40->bulk_in_buffer, sur40->bulk_in_size,
317 			&bulk_read, 1000);
318 
319 		dev_dbg(sur40->dev, "received %d bytes\n", bulk_read);
320 
321 		if (result < 0) {
322 			dev_err(sur40->dev, "error in usb_bulk_read\n");
323 			return;
324 		}
325 
326 		result = bulk_read - sizeof(struct sur40_header);
327 
328 		if (result % sizeof(struct sur40_blob) != 0) {
329 			dev_err(sur40->dev, "transfer size mismatch\n");
330 			return;
331 		}
332 
333 		/* first packet? */
334 		if (need_blobs == -1) {
335 			need_blobs = le16_to_cpu(header->count);
336 			dev_dbg(sur40->dev, "need %d blobs\n", need_blobs);
337 			packet_id = le32_to_cpu(header->packet_id);
338 		}
339 
340 		/*
341 		 * Sanity check. when video data is also being retrieved, the
342 		 * packet ID will usually increase in the middle of a series
343 		 * instead of at the end.
344 		 */
345 		if (packet_id != header->packet_id)
346 			dev_dbg(sur40->dev, "packet ID mismatch\n");
347 
348 		packet_blobs = result / sizeof(struct sur40_blob);
349 		dev_dbg(sur40->dev, "received %d blobs\n", packet_blobs);
350 
351 		/* packets always contain at least 4 blobs, even if empty */
352 		if (packet_blobs > need_blobs)
353 			packet_blobs = need_blobs;
354 
355 		for (i = 0; i < packet_blobs; i++) {
356 			need_blobs--;
357 			dev_dbg(sur40->dev, "processing blob\n");
358 			sur40_report_blob(&(inblob[i]), input);
359 		}
360 
361 	} while (need_blobs > 0);
362 
363 	input_mt_sync_frame(input);
364 	input_sync(input);
365 
366 	sur40_process_video(sur40);
367 }
368 
369 /* deal with video data */
370 static void sur40_process_video(struct sur40_state *sur40)
371 {
372 
373 	struct sur40_image_header *img = (void *)(sur40->bulk_in_buffer);
374 	struct sur40_buffer *new_buf;
375 	struct usb_sg_request sgr;
376 	struct sg_table *sgt;
377 	int result, bulk_read;
378 
379 	if (!vb2_start_streaming_called(&sur40->queue))
380 		return;
381 
382 	/* get a new buffer from the list */
383 	spin_lock(&sur40->qlock);
384 	if (list_empty(&sur40->buf_list)) {
385 		dev_dbg(sur40->dev, "buffer queue empty\n");
386 		spin_unlock(&sur40->qlock);
387 		return;
388 	}
389 	new_buf = list_entry(sur40->buf_list.next, struct sur40_buffer, list);
390 	list_del(&new_buf->list);
391 	spin_unlock(&sur40->qlock);
392 
393 	dev_dbg(sur40->dev, "buffer acquired\n");
394 
395 	/* retrieve data via bulk read */
396 	result = usb_bulk_msg(sur40->usbdev,
397 			usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT),
398 			sur40->bulk_in_buffer, sur40->bulk_in_size,
399 			&bulk_read, 1000);
400 
401 	if (result < 0) {
402 		dev_err(sur40->dev, "error in usb_bulk_read\n");
403 		goto err_poll;
404 	}
405 
406 	if (bulk_read != sizeof(struct sur40_image_header)) {
407 		dev_err(sur40->dev, "received %d bytes (%zd expected)\n",
408 			bulk_read, sizeof(struct sur40_image_header));
409 		goto err_poll;
410 	}
411 
412 	if (le32_to_cpu(img->magic) != VIDEO_HEADER_MAGIC) {
413 		dev_err(sur40->dev, "image magic mismatch\n");
414 		goto err_poll;
415 	}
416 
417 	if (le32_to_cpu(img->size) != sur40_video_format.sizeimage) {
418 		dev_err(sur40->dev, "image size mismatch\n");
419 		goto err_poll;
420 	}
421 
422 	dev_dbg(sur40->dev, "header acquired\n");
423 
424 	sgt = vb2_dma_sg_plane_desc(&new_buf->vb.vb2_buf, 0);
425 
426 	result = usb_sg_init(&sgr, sur40->usbdev,
427 		usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT), 0,
428 		sgt->sgl, sgt->nents, sur40_video_format.sizeimage, 0);
429 	if (result < 0) {
430 		dev_err(sur40->dev, "error %d in usb_sg_init\n", result);
431 		goto err_poll;
432 	}
433 
434 	usb_sg_wait(&sgr);
435 	if (sgr.status < 0) {
436 		dev_err(sur40->dev, "error %d in usb_sg_wait\n", sgr.status);
437 		goto err_poll;
438 	}
439 
440 	dev_dbg(sur40->dev, "image acquired\n");
441 
442 	/* return error if streaming was stopped in the meantime */
443 	if (sur40->sequence == -1)
444 		goto err_poll;
445 
446 	/* mark as finished */
447 	new_buf->vb.vb2_buf.timestamp = ktime_get_ns();
448 	new_buf->vb.sequence = sur40->sequence++;
449 	new_buf->vb.field = V4L2_FIELD_NONE;
450 	vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
451 	dev_dbg(sur40->dev, "buffer marked done\n");
452 	return;
453 
454 err_poll:
455 	vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
456 }
457 
458 /* Initialize input device parameters. */
459 static void sur40_input_setup(struct input_dev *input_dev)
460 {
461 	__set_bit(EV_KEY, input_dev->evbit);
462 	__set_bit(EV_ABS, input_dev->evbit);
463 
464 	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
465 			     0, SENSOR_RES_X, 0, 0);
466 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
467 			     0, SENSOR_RES_Y, 0, 0);
468 
469 	input_set_abs_params(input_dev, ABS_MT_TOOL_X,
470 			     0, SENSOR_RES_X, 0, 0);
471 	input_set_abs_params(input_dev, ABS_MT_TOOL_Y,
472 			     0, SENSOR_RES_Y, 0, 0);
473 
474 	/* max value unknown, but major/minor axis
475 	 * can never be larger than screen */
476 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
477 			     0, SENSOR_RES_X, 0, 0);
478 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR,
479 			     0, SENSOR_RES_Y, 0, 0);
480 
481 	input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
482 
483 	input_mt_init_slots(input_dev, MAX_CONTACTS,
484 			    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
485 }
486 
487 /* Check candidate USB interface. */
488 static int sur40_probe(struct usb_interface *interface,
489 		       const struct usb_device_id *id)
490 {
491 	struct usb_device *usbdev = interface_to_usbdev(interface);
492 	struct sur40_state *sur40;
493 	struct usb_host_interface *iface_desc;
494 	struct usb_endpoint_descriptor *endpoint;
495 	struct input_polled_dev *poll_dev;
496 	int error;
497 
498 	/* Check if we really have the right interface. */
499 	iface_desc = &interface->altsetting[0];
500 	if (iface_desc->desc.bInterfaceClass != 0xFF)
501 		return -ENODEV;
502 
503 	/* Use endpoint #4 (0x86). */
504 	endpoint = &iface_desc->endpoint[4].desc;
505 	if (endpoint->bEndpointAddress != TOUCH_ENDPOINT)
506 		return -ENODEV;
507 
508 	/* Allocate memory for our device state and initialize it. */
509 	sur40 = kzalloc(sizeof(struct sur40_state), GFP_KERNEL);
510 	if (!sur40)
511 		return -ENOMEM;
512 
513 	poll_dev = input_allocate_polled_device();
514 	if (!poll_dev) {
515 		error = -ENOMEM;
516 		goto err_free_dev;
517 	}
518 
519 	/* initialize locks/lists */
520 	INIT_LIST_HEAD(&sur40->buf_list);
521 	spin_lock_init(&sur40->qlock);
522 	mutex_init(&sur40->lock);
523 
524 	/* Set up polled input device control structure */
525 	poll_dev->private = sur40;
526 	poll_dev->poll_interval = POLL_INTERVAL;
527 	poll_dev->open = sur40_open;
528 	poll_dev->poll = sur40_poll;
529 	poll_dev->close = sur40_close;
530 
531 	/* Set up regular input device structure */
532 	sur40_input_setup(poll_dev->input);
533 
534 	poll_dev->input->name = DRIVER_LONG;
535 	usb_to_input_id(usbdev, &poll_dev->input->id);
536 	usb_make_path(usbdev, sur40->phys, sizeof(sur40->phys));
537 	strlcat(sur40->phys, "/input0", sizeof(sur40->phys));
538 	poll_dev->input->phys = sur40->phys;
539 	poll_dev->input->dev.parent = &interface->dev;
540 
541 	sur40->usbdev = usbdev;
542 	sur40->dev = &interface->dev;
543 	sur40->input = poll_dev;
544 
545 	/* use the bulk-in endpoint tested above */
546 	sur40->bulk_in_size = usb_endpoint_maxp(endpoint);
547 	sur40->bulk_in_epaddr = endpoint->bEndpointAddress;
548 	sur40->bulk_in_buffer = kmalloc(sur40->bulk_in_size, GFP_KERNEL);
549 	if (!sur40->bulk_in_buffer) {
550 		dev_err(&interface->dev, "Unable to allocate input buffer.");
551 		error = -ENOMEM;
552 		goto err_free_polldev;
553 	}
554 
555 	/* register the polled input device */
556 	error = input_register_polled_device(poll_dev);
557 	if (error) {
558 		dev_err(&interface->dev,
559 			"Unable to register polled input device.");
560 		goto err_free_buffer;
561 	}
562 
563 	/* register the video master device */
564 	snprintf(sur40->v4l2.name, sizeof(sur40->v4l2.name), "%s", DRIVER_LONG);
565 	error = v4l2_device_register(sur40->dev, &sur40->v4l2);
566 	if (error) {
567 		dev_err(&interface->dev,
568 			"Unable to register video master device.");
569 		goto err_unreg_v4l2;
570 	}
571 
572 	/* initialize the lock and subdevice */
573 	sur40->queue = sur40_queue;
574 	sur40->queue.drv_priv = sur40;
575 	sur40->queue.lock = &sur40->lock;
576 
577 	/* initialize the queue */
578 	error = vb2_queue_init(&sur40->queue);
579 	if (error)
580 		goto err_unreg_v4l2;
581 
582 	sur40->alloc_ctx = vb2_dma_sg_init_ctx(sur40->dev);
583 	if (IS_ERR(sur40->alloc_ctx)) {
584 		dev_err(sur40->dev, "Can't allocate buffer context");
585 		error = PTR_ERR(sur40->alloc_ctx);
586 		goto err_unreg_v4l2;
587 	}
588 
589 	sur40->vdev = sur40_video_device;
590 	sur40->vdev.v4l2_dev = &sur40->v4l2;
591 	sur40->vdev.lock = &sur40->lock;
592 	sur40->vdev.queue = &sur40->queue;
593 	video_set_drvdata(&sur40->vdev, sur40);
594 
595 	error = video_register_device(&sur40->vdev, VFL_TYPE_GRABBER, -1);
596 	if (error) {
597 		dev_err(&interface->dev,
598 			"Unable to register video subdevice.");
599 		goto err_unreg_video;
600 	}
601 
602 	/* we can register the device now, as it is ready */
603 	usb_set_intfdata(interface, sur40);
604 	dev_dbg(&interface->dev, "%s is now attached\n", DRIVER_DESC);
605 
606 	return 0;
607 
608 err_unreg_video:
609 	video_unregister_device(&sur40->vdev);
610 err_unreg_v4l2:
611 	v4l2_device_unregister(&sur40->v4l2);
612 err_free_buffer:
613 	kfree(sur40->bulk_in_buffer);
614 err_free_polldev:
615 	input_free_polled_device(sur40->input);
616 err_free_dev:
617 	kfree(sur40);
618 
619 	return error;
620 }
621 
622 /* Unregister device & clean up. */
623 static void sur40_disconnect(struct usb_interface *interface)
624 {
625 	struct sur40_state *sur40 = usb_get_intfdata(interface);
626 
627 	video_unregister_device(&sur40->vdev);
628 	v4l2_device_unregister(&sur40->v4l2);
629 	vb2_dma_sg_cleanup_ctx(sur40->alloc_ctx);
630 
631 	input_unregister_polled_device(sur40->input);
632 	input_free_polled_device(sur40->input);
633 	kfree(sur40->bulk_in_buffer);
634 	kfree(sur40);
635 
636 	usb_set_intfdata(interface, NULL);
637 	dev_dbg(&interface->dev, "%s is now disconnected\n", DRIVER_DESC);
638 }
639 
640 /*
641  * Setup the constraints of the queue: besides setting the number of planes
642  * per buffer and the size and allocation context of each plane, it also
643  * checks if sufficient buffers have been allocated. Usually 3 is a good
644  * minimum number: many DMA engines need a minimum of 2 buffers in the
645  * queue and you need to have another available for userspace processing.
646  */
647 static int sur40_queue_setup(struct vb2_queue *q,
648 		       unsigned int *nbuffers, unsigned int *nplanes,
649 		       unsigned int sizes[], void *alloc_ctxs[])
650 {
651 	struct sur40_state *sur40 = vb2_get_drv_priv(q);
652 
653 	if (q->num_buffers + *nbuffers < 3)
654 		*nbuffers = 3 - q->num_buffers;
655 	alloc_ctxs[0] = sur40->alloc_ctx;
656 
657 	if (*nplanes)
658 		return sizes[0] < sur40_video_format.sizeimage ? -EINVAL : 0;
659 
660 	*nplanes = 1;
661 	sizes[0] = sur40_video_format.sizeimage;
662 
663 	return 0;
664 }
665 
666 /*
667  * Prepare the buffer for queueing to the DMA engine: check and set the
668  * payload size.
669  */
670 static int sur40_buffer_prepare(struct vb2_buffer *vb)
671 {
672 	struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
673 	unsigned long size = sur40_video_format.sizeimage;
674 
675 	if (vb2_plane_size(vb, 0) < size) {
676 		dev_err(&sur40->usbdev->dev, "buffer too small (%lu < %lu)\n",
677 			 vb2_plane_size(vb, 0), size);
678 		return -EINVAL;
679 	}
680 
681 	vb2_set_plane_payload(vb, 0, size);
682 	return 0;
683 }
684 
685 /*
686  * Queue this buffer to the DMA engine.
687  */
688 static void sur40_buffer_queue(struct vb2_buffer *vb)
689 {
690 	struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
691 	struct sur40_buffer *buf = (struct sur40_buffer *)vb;
692 
693 	spin_lock(&sur40->qlock);
694 	list_add_tail(&buf->list, &sur40->buf_list);
695 	spin_unlock(&sur40->qlock);
696 }
697 
698 static void return_all_buffers(struct sur40_state *sur40,
699 			       enum vb2_buffer_state state)
700 {
701 	struct sur40_buffer *buf, *node;
702 
703 	spin_lock(&sur40->qlock);
704 	list_for_each_entry_safe(buf, node, &sur40->buf_list, list) {
705 		vb2_buffer_done(&buf->vb.vb2_buf, state);
706 		list_del(&buf->list);
707 	}
708 	spin_unlock(&sur40->qlock);
709 }
710 
711 /*
712  * Start streaming. First check if the minimum number of buffers have been
713  * queued. If not, then return -ENOBUFS and the vb2 framework will call
714  * this function again the next time a buffer has been queued until enough
715  * buffers are available to actually start the DMA engine.
716  */
717 static int sur40_start_streaming(struct vb2_queue *vq, unsigned int count)
718 {
719 	struct sur40_state *sur40 = vb2_get_drv_priv(vq);
720 
721 	sur40->sequence = 0;
722 	return 0;
723 }
724 
725 /*
726  * Stop the DMA engine. Any remaining buffers in the DMA queue are dequeued
727  * and passed on to the vb2 framework marked as STATE_ERROR.
728  */
729 static void sur40_stop_streaming(struct vb2_queue *vq)
730 {
731 	struct sur40_state *sur40 = vb2_get_drv_priv(vq);
732 	sur40->sequence = -1;
733 
734 	/* Release all active buffers */
735 	return_all_buffers(sur40, VB2_BUF_STATE_ERROR);
736 }
737 
738 /* V4L ioctl */
739 static int sur40_vidioc_querycap(struct file *file, void *priv,
740 				 struct v4l2_capability *cap)
741 {
742 	struct sur40_state *sur40 = video_drvdata(file);
743 
744 	strlcpy(cap->driver, DRIVER_SHORT, sizeof(cap->driver));
745 	strlcpy(cap->card, DRIVER_LONG, sizeof(cap->card));
746 	usb_make_path(sur40->usbdev, cap->bus_info, sizeof(cap->bus_info));
747 	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE |
748 		V4L2_CAP_READWRITE |
749 		V4L2_CAP_STREAMING;
750 	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
751 	return 0;
752 }
753 
754 static int sur40_vidioc_enum_input(struct file *file, void *priv,
755 				   struct v4l2_input *i)
756 {
757 	if (i->index != 0)
758 		return -EINVAL;
759 	i->type = V4L2_INPUT_TYPE_CAMERA;
760 	i->std = V4L2_STD_UNKNOWN;
761 	strlcpy(i->name, "In-Cell Sensor", sizeof(i->name));
762 	i->capabilities = 0;
763 	return 0;
764 }
765 
766 static int sur40_vidioc_s_input(struct file *file, void *priv, unsigned int i)
767 {
768 	return (i == 0) ? 0 : -EINVAL;
769 }
770 
771 static int sur40_vidioc_g_input(struct file *file, void *priv, unsigned int *i)
772 {
773 	*i = 0;
774 	return 0;
775 }
776 
777 static int sur40_vidioc_fmt(struct file *file, void *priv,
778 			    struct v4l2_format *f)
779 {
780 	f->fmt.pix = sur40_video_format;
781 	return 0;
782 }
783 
784 static int sur40_vidioc_enum_fmt(struct file *file, void *priv,
785 				 struct v4l2_fmtdesc *f)
786 {
787 	if (f->index != 0)
788 		return -EINVAL;
789 	strlcpy(f->description, "8-bit greyscale", sizeof(f->description));
790 	f->pixelformat = V4L2_PIX_FMT_GREY;
791 	f->flags = 0;
792 	return 0;
793 }
794 
795 static int sur40_vidioc_enum_framesizes(struct file *file, void *priv,
796 					struct v4l2_frmsizeenum *f)
797 {
798 	if ((f->index != 0) || (f->pixel_format != V4L2_PIX_FMT_GREY))
799 		return -EINVAL;
800 
801 	f->type = V4L2_FRMSIZE_TYPE_DISCRETE;
802 	f->discrete.width  = sur40_video_format.width;
803 	f->discrete.height = sur40_video_format.height;
804 	return 0;
805 }
806 
807 static int sur40_vidioc_enum_frameintervals(struct file *file, void *priv,
808 					    struct v4l2_frmivalenum *f)
809 {
810 	if ((f->index > 1) || (f->pixel_format != V4L2_PIX_FMT_GREY)
811 		|| (f->width  != sur40_video_format.width)
812 		|| (f->height != sur40_video_format.height))
813 			return -EINVAL;
814 
815 	f->type = V4L2_FRMIVAL_TYPE_DISCRETE;
816 	f->discrete.denominator  = 60/(f->index+1);
817 	f->discrete.numerator = 1;
818 	return 0;
819 }
820 
821 
822 static const struct usb_device_id sur40_table[] = {
823 	{ USB_DEVICE(ID_MICROSOFT, ID_SUR40) },  /* Samsung SUR40 */
824 	{ }                                      /* terminating null entry */
825 };
826 MODULE_DEVICE_TABLE(usb, sur40_table);
827 
828 /* V4L2 structures */
829 static const struct vb2_ops sur40_queue_ops = {
830 	.queue_setup		= sur40_queue_setup,
831 	.buf_prepare		= sur40_buffer_prepare,
832 	.buf_queue		= sur40_buffer_queue,
833 	.start_streaming	= sur40_start_streaming,
834 	.stop_streaming		= sur40_stop_streaming,
835 	.wait_prepare		= vb2_ops_wait_prepare,
836 	.wait_finish		= vb2_ops_wait_finish,
837 };
838 
839 static const struct vb2_queue sur40_queue = {
840 	.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
841 	/*
842 	 * VB2_USERPTR in currently not enabled: passing a user pointer to
843 	 * dma-sg will result in segment sizes that are not a multiple of
844 	 * 512 bytes, which is required by the host controller.
845 	*/
846 	.io_modes = VB2_MMAP | VB2_READ | VB2_DMABUF,
847 	.buf_struct_size = sizeof(struct sur40_buffer),
848 	.ops = &sur40_queue_ops,
849 	.mem_ops = &vb2_dma_sg_memops,
850 	.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC,
851 	.min_buffers_needed = 3,
852 };
853 
854 static const struct v4l2_file_operations sur40_video_fops = {
855 	.owner = THIS_MODULE,
856 	.open = v4l2_fh_open,
857 	.release = vb2_fop_release,
858 	.unlocked_ioctl = video_ioctl2,
859 	.read = vb2_fop_read,
860 	.mmap = vb2_fop_mmap,
861 	.poll = vb2_fop_poll,
862 };
863 
864 static const struct v4l2_ioctl_ops sur40_video_ioctl_ops = {
865 
866 	.vidioc_querycap	= sur40_vidioc_querycap,
867 
868 	.vidioc_enum_fmt_vid_cap = sur40_vidioc_enum_fmt,
869 	.vidioc_try_fmt_vid_cap	= sur40_vidioc_fmt,
870 	.vidioc_s_fmt_vid_cap	= sur40_vidioc_fmt,
871 	.vidioc_g_fmt_vid_cap	= sur40_vidioc_fmt,
872 
873 	.vidioc_enum_framesizes = sur40_vidioc_enum_framesizes,
874 	.vidioc_enum_frameintervals = sur40_vidioc_enum_frameintervals,
875 
876 	.vidioc_enum_input	= sur40_vidioc_enum_input,
877 	.vidioc_g_input		= sur40_vidioc_g_input,
878 	.vidioc_s_input		= sur40_vidioc_s_input,
879 
880 	.vidioc_reqbufs		= vb2_ioctl_reqbufs,
881 	.vidioc_create_bufs	= vb2_ioctl_create_bufs,
882 	.vidioc_querybuf	= vb2_ioctl_querybuf,
883 	.vidioc_qbuf		= vb2_ioctl_qbuf,
884 	.vidioc_dqbuf		= vb2_ioctl_dqbuf,
885 	.vidioc_expbuf		= vb2_ioctl_expbuf,
886 
887 	.vidioc_streamon	= vb2_ioctl_streamon,
888 	.vidioc_streamoff	= vb2_ioctl_streamoff,
889 };
890 
891 static const struct video_device sur40_video_device = {
892 	.name = DRIVER_LONG,
893 	.fops = &sur40_video_fops,
894 	.ioctl_ops = &sur40_video_ioctl_ops,
895 	.release = video_device_release_empty,
896 };
897 
898 static const struct v4l2_pix_format sur40_video_format = {
899 	.pixelformat = V4L2_PIX_FMT_GREY,
900 	.width  = SENSOR_RES_X / 2,
901 	.height = SENSOR_RES_Y / 2,
902 	.field = V4L2_FIELD_NONE,
903 	.colorspace = V4L2_COLORSPACE_SRGB,
904 	.bytesperline = SENSOR_RES_X / 2,
905 	.sizeimage = (SENSOR_RES_X/2) * (SENSOR_RES_Y/2),
906 };
907 
908 /* USB-specific object needed to register this driver with the USB subsystem. */
909 static struct usb_driver sur40_driver = {
910 	.name = DRIVER_SHORT,
911 	.probe = sur40_probe,
912 	.disconnect = sur40_disconnect,
913 	.id_table = sur40_table,
914 };
915 
916 module_usb_driver(sur40_driver);
917 
918 MODULE_AUTHOR(DRIVER_AUTHOR);
919 MODULE_DESCRIPTION(DRIVER_DESC);
920 MODULE_LICENSE("GPL");
921