drivers/input/touchscreen/sur40.c

   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-dma-sg.h>
  42
  43 /* read 512 bytes from endpoint 0x86 -> get header + blobs */
  44 struct sur40_header {
  45
  46         __le16 type;       /* always 0x0001 */
  47         __le16 count;      /* count of blobs (if 0: continue prev. packet) */
  48
  49         __le32 packet_id;  /* unique ID for all packets in one frame */
  50
  51         __le32 timestamp;  /* milliseconds (inc. by 16 or 17 each frame) */
  52         __le32 unknown;    /* "epoch?" always 02/03 00 00 00 */
  53
  54 } __packed;
  55
  56 struct sur40_blob {
  57
  58         __le16 blob_id;
  59
  60         u8 action;         /* 0x02 = enter/exit, 0x03 = update (?) */
  61         u8 unknown;        /* always 0x01 or 0x02 (no idea what this is?) */
  62
  63         __le16 bb_pos_x;   /* upper left corner of bounding box */
  64         __le16 bb_pos_y;
  65
  66         __le16 bb_size_x;  /* size of bounding box */
  67         __le16 bb_size_y;
  68
  69         __le16 pos_x;      /* finger tip position */
  70         __le16 pos_y;
  71
  72         __le16 ctr_x;      /* centroid position */
  73         __le16 ctr_y;
  74
  75         __le16 axis_x;     /* somehow related to major/minor axis, mostly: */
  76         __le16 axis_y;     /* axis_x == bb_size_y && axis_y == bb_size_x */
  77
  78         __le32 angle;      /* orientation in radians relative to x axis -
  79                               actually an IEEE754 float, don't use in kernel */
  80
  81         __le32 area;       /* size in pixels/pressure (?) */
  82
  83         u8 padding[32];
  84
  85 } __packed;
  86
  87 /* combined header/blob data */
  88 struct sur40_data {
  89         struct sur40_header header;
  90         struct sur40_blob   blobs[];
  91 } __packed;
  92
  93 /* read 512 bytes from endpoint 0x82 -> get header below
  94  * continue reading 16k blocks until header.size bytes read */
  95 struct sur40_image_header {
  96         __le32 magic;     /* "SUBF" */
  97         __le32 packet_id;
  98         __le32 size;      /* always 0x0007e900 = 960x540 */
  99         __le32 timestamp; /* milliseconds (increases by 16 or 17 each frame) */
 100         __le32 unknown;   /* "epoch?" always 02/03 00 00 00 */
 101 } __packed;
 102
 103 /* version information */
 104 #define DRIVER_SHORT   "sur40"
 105 #define DRIVER_LONG    "Samsung SUR40"
 106 #define DRIVER_AUTHOR  "Florian 'floe' Echtler <floe@butterbrot.org>"
 107 #define DRIVER_DESC    "Surface2.0/SUR40/PixelSense input driver"
 108
 109 /* vendor and device IDs */
 110 #define ID_MICROSOFT 0x045e
 111 #define ID_SUR40     0x0775
 112
 113 /* sensor resolution */
 114 #define SENSOR_RES_X 1920
 115 #define SENSOR_RES_Y 1080
 116
 117 /* touch data endpoint */
 118 #define TOUCH_ENDPOINT 0x86
 119
 120 /* video data endpoint */
 121 #define VIDEO_ENDPOINT 0x82
 122
 123 /* video header fields */
 124 #define VIDEO_HEADER_MAGIC 0x46425553
 125 #define VIDEO_PACKET_SIZE  16384
 126
 127 /* polling interval (ms) */
 128 #define POLL_INTERVAL 10
 129
 130 /* maximum number of contacts FIXME: this is a guess? */
 131 #define MAX_CONTACTS 64
 132
 133 /* control commands */
 134 #define SUR40_GET_VERSION 0xb0 /* 12 bytes string    */
 135 #define SUR40_UNKNOWN1    0xb3 /*  5 bytes           */
 136 #define SUR40_UNKNOWN2    0xc1 /* 24 bytes           */
 137
 138 #define SUR40_GET_STATE   0xc5 /*  4 bytes state (?) */
 139 #define SUR40_GET_SENSORS 0xb1 /*  8 bytes sensors   */
 140
 141 /* master device state */
 142 struct sur40_state {
 143
 144         struct usb_device *usbdev;
 145         struct device *dev;
 146         struct input_polled_dev *input;
 147
 148         struct v4l2_device v4l2;
 149         struct video_device vdev;
 150         struct mutex lock;
 151
 152         struct vb2_queue queue;
 153         struct vb2_alloc_ctx *alloc_ctx;
 154         struct list_head buf_list;
 155         spinlock_t qlock;
 156         int sequence;
 157
 158         struct sur40_data *bulk_in_buffer;
 159         size_t bulk_in_size;
 160         u8 bulk_in_epaddr;
 161
 162         char phys[64];
 163 };
 164
 165 struct sur40_buffer {
 166         struct vb2_buffer vb;
 167         struct list_head list;
 168 };
 169
 170 /* forward declarations */
 171 static const struct video_device sur40_video_device;
 172 static const struct v4l2_pix_format sur40_video_format;
 173 static const struct vb2_queue sur40_queue;
 174 static void sur40_process_video(struct sur40_state *sur40);
 175
 176 /*
 177  * Note: an earlier, non-public version of this driver used USB_RECIP_ENDPOINT
 178  * here by mistake which is very likely to have corrupted the firmware EEPROM
 179  * on two separate SUR40 devices. Thanks to Alan Stern who spotted this bug.
 180  * Should you ever run into a similar problem, the background story to this
 181  * incident and instructions on how to fix the corrupted EEPROM are available
 182  * at https://floe.butterbrot.org/matrix/hacking/surface/brick.html
 183 */
 184
 185 /* command wrapper */
 186 static int sur40_command(struct sur40_state *dev,
 187                          u8 command, u16 index, void *buffer, u16 size)
 188 {
 189         return usb_control_msg(dev->usbdev, usb_rcvctrlpipe(dev->usbdev, 0),
 190                                command,
 191                                USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
 192                                0x00, index, buffer, size, 1000);
 193 }
 194
 195 /* Initialization routine, called from sur40_open */
 196 static int sur40_init(struct sur40_state *dev)
 197 {
 198         int result;
 199         u8 buffer[24];
 200
 201         /* stupidly replay the original MS driver init sequence */
 202         result = sur40_command(dev, SUR40_GET_VERSION, 0x00, buffer, 12);
 203         if (result < 0)
 204                 return result;
 205
 206         result = sur40_command(dev, SUR40_GET_VERSION, 0x01, buffer, 12);
 207         if (result < 0)
 208                 return result;
 209
 210         result = sur40_command(dev, SUR40_GET_VERSION, 0x02, buffer, 12);
 211         if (result < 0)
 212                 return result;
 213
 214         result = sur40_command(dev, SUR40_UNKNOWN2,    0x00, buffer, 24);
 215         if (result < 0)
 216                 return result;
 217
 218         result = sur40_command(dev, SUR40_UNKNOWN1,    0x00, buffer,  5);
 219         if (result < 0)
 220                 return result;
 221
 222         result = sur40_command(dev, SUR40_GET_VERSION, 0x03, buffer, 12);
 223
 224         /*
 225          * Discard the result buffer - no known data inside except
 226          * some version strings, maybe extract these sometime...
 227          */
 228
 229         return result;
 230 }
 231
 232 /*
 233  * Callback routines from input_polled_dev
 234  */
 235
 236 /* Enable the device, polling will now start. */
 237 static void sur40_open(struct input_polled_dev *polldev)
 238 {
 239         struct sur40_state *sur40 = polldev->private;
 240
 241         dev_dbg(sur40->dev, "open\n");
 242         sur40_init(sur40);
 243 }
 244
 245 /* Disable device, polling has stopped. */
 246 static void sur40_close(struct input_polled_dev *polldev)
 247 {
 248         struct sur40_state *sur40 = polldev->private;
 249
 250         dev_dbg(sur40->dev, "close\n");
 251         /*
 252          * There is no known way to stop the device, so we simply
 253          * stop polling.
 254          */
 255 }
 256
 257 /*
 258  * This function is called when a whole contact has been processed,
 259  * so that it can assign it to a slot and store the data there.
 260  */
 261 static void sur40_report_blob(struct sur40_blob *blob, struct input_dev *input)
 262 {
 263         int wide, major, minor;
 264
 265         int bb_size_x = le16_to_cpu(blob->bb_size_x);
 266         int bb_size_y = le16_to_cpu(blob->bb_size_y);
 267
 268         int pos_x = le16_to_cpu(blob->pos_x);
 269         int pos_y = le16_to_cpu(blob->pos_y);
 270
 271         int ctr_x = le16_to_cpu(blob->ctr_x);
 272         int ctr_y = le16_to_cpu(blob->ctr_y);
 273
 274         int slotnum = input_mt_get_slot_by_key(input, blob->blob_id);
 275         if (slotnum < 0 || slotnum >= MAX_CONTACTS)
 276                 return;
 277
 278         input_mt_slot(input, slotnum);
 279         input_mt_report_slot_state(input, MT_TOOL_FINGER, 1);
 280         wide = (bb_size_x > bb_size_y);
 281         major = max(bb_size_x, bb_size_y);
 282         minor = min(bb_size_x, bb_size_y);
 283
 284         input_report_abs(input, ABS_MT_POSITION_X, pos_x);
 285         input_report_abs(input, ABS_MT_POSITION_Y, pos_y);
 286         input_report_abs(input, ABS_MT_TOOL_X, ctr_x);
 287         input_report_abs(input, ABS_MT_TOOL_Y, ctr_y);
 288
 289         /* TODO: use a better orientation measure */
 290         input_report_abs(input, ABS_MT_ORIENTATION, wide);
 291         input_report_abs(input, ABS_MT_TOUCH_MAJOR, major);
 292         input_report_abs(input, ABS_MT_TOUCH_MINOR, minor);
 293 }
 294
 295 /* core function: poll for new input data */
 296 static void sur40_poll(struct input_polled_dev *polldev)
 297 {
 298         struct sur40_state *sur40 = polldev->private;
 299         struct input_dev *input = polldev->input;
 300         int result, bulk_read, need_blobs, packet_blobs, i;
 301         u32 uninitialized_var(packet_id);
 302
 303         struct sur40_header *header = &sur40->bulk_in_buffer->header;
 304         struct sur40_blob *inblob = &sur40->bulk_in_buffer->blobs[0];
 305
 306         dev_dbg(sur40->dev, "poll\n");
 307
 308         need_blobs = -1;
 309
 310         do {
 311
 312                 /* perform a blocking bulk read to get data from the device */
 313                 result = usb_bulk_msg(sur40->usbdev,
 314                         usb_rcvbulkpipe(sur40->usbdev, sur40->bulk_in_epaddr),
 315                         sur40->bulk_in_buffer, sur40->bulk_in_size,
 316                         &bulk_read, 1000);
 317
 318                 dev_dbg(sur40->dev, "received %d bytes\n", bulk_read);
 319
 320                 if (result < 0) {
 321                         dev_err(sur40->dev, "error in usb_bulk_read\n");
 322                         return;
 323                 }
 324
 325                 result = bulk_read - sizeof(struct sur40_header);
 326
 327                 if (result % sizeof(struct sur40_blob) != 0) {
 328                         dev_err(sur40->dev, "transfer size mismatch\n");
 329                         return;
 330                 }
 331
 332                 /* first packet? */
 333                 if (need_blobs == -1) {
 334                         need_blobs = le16_to_cpu(header->count);
 335                         dev_dbg(sur40->dev, "need %d blobs\n", need_blobs);
 336                         packet_id = le32_to_cpu(header->packet_id);
 337                 }
 338
 339                 /*
 340                  * Sanity check. when video data is also being retrieved, the
 341                  * packet ID will usually increase in the middle of a series
 342                  * instead of at the end.
 343                  */
 344                 if (packet_id != header->packet_id)
 345                         dev_warn(sur40->dev, "packet ID mismatch\n");
 346
 347                 packet_blobs = result / sizeof(struct sur40_blob);
 348                 dev_dbg(sur40->dev, "received %d blobs\n", packet_blobs);
 349
 350                 /* packets always contain at least 4 blobs, even if empty */
 351                 if (packet_blobs > need_blobs)
 352                         packet_blobs = need_blobs;
 353
 354                 for (i = 0; i < packet_blobs; i++) {
 355                         need_blobs--;
 356                         dev_dbg(sur40->dev, "processing blob\n");
 357                         sur40_report_blob(&(inblob[i]), input);
 358                 }
 359
 360         } while (need_blobs > 0);
 361
 362         input_mt_sync_frame(input);
 363         input_sync(input);
 364
 365         sur40_process_video(sur40);
 366 }
 367
 368 /* deal with video data */
 369 static void sur40_process_video(struct sur40_state *sur40)
 370 {
 371
 372         struct sur40_image_header *img = (void *)(sur40->bulk_in_buffer);
 373         struct sur40_buffer *new_buf;
 374         struct usb_sg_request sgr;
 375         struct sg_table *sgt;
 376         int result, bulk_read;
 377
 378         if (!vb2_start_streaming_called(&sur40->queue))
 379                 return;
 380
 381         /* get a new buffer from the list */
 382         spin_lock(&sur40->qlock);
 383         if (list_empty(&sur40->buf_list)) {
 384                 dev_dbg(sur40->dev, "buffer queue empty\n");
 385                 spin_unlock(&sur40->qlock);
 386                 return;
 387         }
 388         new_buf = list_entry(sur40->buf_list.next, struct sur40_buffer, list);
 389         list_del(&new_buf->list);
 390         spin_unlock(&sur40->qlock);
 391
 392         /* retrieve data via bulk read */
 393         result = usb_bulk_msg(sur40->usbdev,
 394                         usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT),
 395                         sur40->bulk_in_buffer, sur40->bulk_in_size,
 396                         &bulk_read, 1000);
 397
 398         if (result < 0) {
 399                 dev_err(sur40->dev, "error in usb_bulk_read\n");
 400                 goto err_poll;
 401         }
 402
 403         if (bulk_read != sizeof(struct sur40_image_header)) {
 404                 dev_err(sur40->dev, "received %d bytes (%zd expected)\n",
 405                         bulk_read, sizeof(struct sur40_image_header));
 406                 goto err_poll;
 407         }
 408
 409         if (le32_to_cpu(img->magic) != VIDEO_HEADER_MAGIC) {
 410                 dev_err(sur40->dev, "image magic mismatch\n");
 411                 goto err_poll;
 412         }
 413
 414         if (le32_to_cpu(img->size) != sur40_video_format.sizeimage) {
 415                 dev_err(sur40->dev, "image size mismatch\n");
 416                 goto err_poll;
 417         }
 418
 419         sgt = vb2_dma_sg_plane_desc(&new_buf->vb, 0);
 420
 421         result = usb_sg_init(&sgr, sur40->usbdev,
 422                 usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT), 0,
 423                 sgt->sgl, sgt->nents, sur40_video_format.sizeimage, 0);
 424         if (result < 0) {
 425                 dev_err(sur40->dev, "error %d in usb_sg_init\n", result);
 426                 goto err_poll;
 427         }
 428
 429         usb_sg_wait(&sgr);
 430         if (sgr.status < 0) {
 431                 dev_err(sur40->dev, "error %d in usb_sg_wait\n", sgr.status);
 432                 goto err_poll;
 433         }
 434
 435         /* mark as finished */
 436         v4l2_get_timestamp(&new_buf->vb.v4l2_buf.timestamp);
 437         new_buf->vb.v4l2_buf.sequence = sur40->sequence++;
 438         new_buf->vb.v4l2_buf.field = V4L2_FIELD_NONE;
 439         vb2_buffer_done(&new_buf->vb, VB2_BUF_STATE_DONE);
 440         return;
 441
 442 err_poll:
 443         vb2_buffer_done(&new_buf->vb, VB2_BUF_STATE_ERROR);
 444 }
 445
 446 /* Initialize input device parameters. */
 447 static void sur40_input_setup(struct input_dev *input_dev)
 448 {
 449         __set_bit(EV_KEY, input_dev->evbit);
 450         __set_bit(EV_ABS, input_dev->evbit);
 451
 452         input_set_abs_params(input_dev, ABS_MT_POSITION_X,
 453                              0, SENSOR_RES_X, 0, 0);
 454         input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
 455                              0, SENSOR_RES_Y, 0, 0);
 456
 457         input_set_abs_params(input_dev, ABS_MT_TOOL_X,
 458                              0, SENSOR_RES_X, 0, 0);
 459         input_set_abs_params(input_dev, ABS_MT_TOOL_Y,
 460                              0, SENSOR_RES_Y, 0, 0);
 461
 462         /* max value unknown, but major/minor axis
 463          * can never be larger than screen */
 464         input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
 465                              0, SENSOR_RES_X, 0, 0);
 466         input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR,
 467                              0, SENSOR_RES_Y, 0, 0);
 468
 469         input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
 470
 471         input_mt_init_slots(input_dev, MAX_CONTACTS,
 472                             INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
 473 }
 474
 475 /* Check candidate USB interface. */
 476 static int sur40_probe(struct usb_interface *interface,
 477                        const struct usb_device_id *id)
 478 {
 479         struct usb_device *usbdev = interface_to_usbdev(interface);
 480         struct sur40_state *sur40;
 481         struct usb_host_interface *iface_desc;
 482         struct usb_endpoint_descriptor *endpoint;
 483         struct input_polled_dev *poll_dev;
 484         int error;
 485
 486         /* Check if we really have the right interface. */
 487         iface_desc = &interface->altsetting[0];
 488         if (iface_desc->desc.bInterfaceClass != 0xFF)
 489                 return -ENODEV;
 490
 491         /* Use endpoint #4 (0x86). */
 492         endpoint = &iface_desc->endpoint[4].desc;
 493         if (endpoint->bEndpointAddress != TOUCH_ENDPOINT)
 494                 return -ENODEV;
 495
 496         /* Allocate memory for our device state and initialize it. */
 497         sur40 = kzalloc(sizeof(struct sur40_state), GFP_KERNEL);
 498         if (!sur40)
 499                 return -ENOMEM;
 500
 501         poll_dev = input_allocate_polled_device();
 502         if (!poll_dev) {
 503                 error = -ENOMEM;
 504                 goto err_free_dev;
 505         }
 506
 507         /* initialize locks/lists */
 508         INIT_LIST_HEAD(&sur40->buf_list);
 509         spin_lock_init(&sur40->qlock);
 510         mutex_init(&sur40->lock);
 511
 512         /* Set up polled input device control structure */
 513         poll_dev->private = sur40;
 514         poll_dev->poll_interval = POLL_INTERVAL;
 515         poll_dev->open = sur40_open;
 516         poll_dev->poll = sur40_poll;
 517         poll_dev->close = sur40_close;
 518
 519         /* Set up regular input device structure */
 520         sur40_input_setup(poll_dev->input);
 521
 522         poll_dev->input->name = DRIVER_LONG;
 523         usb_to_input_id(usbdev, &poll_dev->input->id);
 524         usb_make_path(usbdev, sur40->phys, sizeof(sur40->phys));
 525         strlcat(sur40->phys, "/input0", sizeof(sur40->phys));
 526         poll_dev->input->phys = sur40->phys;
 527         poll_dev->input->dev.parent = &interface->dev;
 528
 529         sur40->usbdev = usbdev;
 530         sur40->dev = &interface->dev;
 531         sur40->input = poll_dev;
 532
 533         /* use the bulk-in endpoint tested above */
 534         sur40->bulk_in_size = usb_endpoint_maxp(endpoint);
 535         sur40->bulk_in_epaddr = endpoint->bEndpointAddress;
 536         sur40->bulk_in_buffer = kmalloc(sur40->bulk_in_size, GFP_KERNEL);
 537         if (!sur40->bulk_in_buffer) {
 538                 dev_err(&interface->dev, "Unable to allocate input buffer.");
 539                 error = -ENOMEM;
 540                 goto err_free_polldev;
 541         }
 542
 543         /* register the polled input device */
 544         error = input_register_polled_device(poll_dev);
 545         if (error) {
 546                 dev_err(&interface->dev,
 547                         "Unable to register polled input device.");
 548                 goto err_free_buffer;
 549         }
 550
 551         /* register the video master device */
 552         snprintf(sur40->v4l2.name, sizeof(sur40->v4l2.name), "%s", DRIVER_LONG);
 553         error = v4l2_device_register(sur40->dev, &sur40->v4l2);
 554         if (error) {
 555                 dev_err(&interface->dev,
 556                         "Unable to register video master device.");
 557                 goto err_unreg_v4l2;
 558         }
 559
 560         /* initialize the lock and subdevice */
 561         sur40->queue = sur40_queue;
 562         sur40->queue.drv_priv = sur40;
 563         sur40->queue.lock = &sur40->lock;
 564
 565         /* initialize the queue */
 566         error = vb2_queue_init(&sur40->queue);
 567         if (error)
 568                 goto err_unreg_v4l2;
 569
 570         sur40->alloc_ctx = vb2_dma_sg_init_ctx(sur40->dev);
 571         if (IS_ERR(sur40->alloc_ctx)) {
 572                 dev_err(sur40->dev, "Can't allocate buffer context");
 573                 goto err_unreg_v4l2;
 574         }
 575
 576         sur40->vdev = sur40_video_device;
 577         sur40->vdev.v4l2_dev = &sur40->v4l2;
 578         sur40->vdev.lock = &sur40->lock;
 579         sur40->vdev.queue = &sur40->queue;
 580         video_set_drvdata(&sur40->vdev, sur40);
 581
 582         error = video_register_device(&sur40->vdev, VFL_TYPE_GRABBER, -1);
 583         if (error) {
 584                 dev_err(&interface->dev,
 585                         "Unable to register video subdevice.");
 586                 goto err_unreg_video;
 587         }
 588
 589         /* we can register the device now, as it is ready */
 590         usb_set_intfdata(interface, sur40);
 591         dev_dbg(&interface->dev, "%s is now attached\n", DRIVER_DESC);
 592
 593         return 0;
 594
 595 err_unreg_video:
 596         video_unregister_device(&sur40->vdev);
 597 err_unreg_v4l2:
 598         v4l2_device_unregister(&sur40->v4l2);
 599 err_free_buffer:
 600         kfree(sur40->bulk_in_buffer);
 601 err_free_polldev:
 602         input_free_polled_device(sur40->input);
 603 err_free_dev:
 604         kfree(sur40);
 605
 606         return error;
 607 }
 608
 609 /* Unregister device & clean up. */
 610 static void sur40_disconnect(struct usb_interface *interface)
 611 {
 612         struct sur40_state *sur40 = usb_get_intfdata(interface);
 613
 614         video_unregister_device(&sur40->vdev);
 615         v4l2_device_unregister(&sur40->v4l2);
 616         vb2_dma_sg_cleanup_ctx(sur40->alloc_ctx);
 617
 618         input_unregister_polled_device(sur40->input);
 619         input_free_polled_device(sur40->input);
 620         kfree(sur40->bulk_in_buffer);
 621         kfree(sur40);
 622
 623         usb_set_intfdata(interface, NULL);
 624         dev_dbg(&interface->dev, "%s is now disconnected\n", DRIVER_DESC);
 625 }
 626
 627 /*
 628  * Setup the constraints of the queue: besides setting the number of planes
 629  * per buffer and the size and allocation context of each plane, it also
 630  * checks if sufficient buffers have been allocated. Usually 3 is a good
 631  * minimum number: many DMA engines need a minimum of 2 buffers in the
 632  * queue and you need to have another available for userspace processing.
 633  */
 634 static int sur40_queue_setup(struct vb2_queue *q, const struct v4l2_format *fmt,
 635                        unsigned int *nbuffers, unsigned int *nplanes,
 636                        unsigned int sizes[], void *alloc_ctxs[])
 637 {
 638         struct sur40_state *sur40 = vb2_get_drv_priv(q);
 639
 640         if (q->num_buffers + *nbuffers < 3)
 641                 *nbuffers = 3 - q->num_buffers;
 642
 643         if (fmt && fmt->fmt.pix.sizeimage < sur40_video_format.sizeimage)
 644                 return -EINVAL;
 645
 646         *nplanes = 1;
 647         sizes[0] = fmt ? fmt->fmt.pix.sizeimage : sur40_video_format.sizeimage;
 648         alloc_ctxs[0] = sur40->alloc_ctx;
 649
 650         return 0;
 651 }
 652
 653 /*
 654  * Prepare the buffer for queueing to the DMA engine: check and set the
 655  * payload size.
 656  */
 657 static int sur40_buffer_prepare(struct vb2_buffer *vb)
 658 {
 659         struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
 660         unsigned long size = sur40_video_format.sizeimage;
 661
 662         if (vb2_plane_size(vb, 0) < size) {
 663                 dev_err(&sur40->usbdev->dev, "buffer too small (%lu < %lu)\n",
 664                          vb2_plane_size(vb, 0), size);
 665                 return -EINVAL;
 666         }
 667
 668         vb2_set_plane_payload(vb, 0, size);
 669         return 0;
 670 }
 671
 672 /*
 673  * Queue this buffer to the DMA engine.
 674  */
 675 static void sur40_buffer_queue(struct vb2_buffer *vb)
 676 {
 677         struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
 678         struct sur40_buffer *buf = (struct sur40_buffer *)vb;
 679
 680         spin_lock(&sur40->qlock);
 681         list_add_tail(&buf->list, &sur40->buf_list);
 682         spin_unlock(&sur40->qlock);
 683 }
 684
 685 static void return_all_buffers(struct sur40_state *sur40,
 686                                enum vb2_buffer_state state)
 687 {
 688         struct sur40_buffer *buf, *node;
 689
 690         spin_lock(&sur40->qlock);
 691         list_for_each_entry_safe(buf, node, &sur40->buf_list, list) {
 692                 vb2_buffer_done(&buf->vb, state);
 693                 list_del(&buf->list);
 694         }
 695         spin_unlock(&sur40->qlock);
 696 }
 697
 698 /*
 699  * Start streaming. First check if the minimum number of buffers have been
 700  * queued. If not, then return -ENOBUFS and the vb2 framework will call
 701  * this function again the next time a buffer has been queued until enough
 702  * buffers are available to actually start the DMA engine.
 703  */
 704 static int sur40_start_streaming(struct vb2_queue *vq, unsigned int count)
 705 {
 706         struct sur40_state *sur40 = vb2_get_drv_priv(vq);
 707
 708         sur40->sequence = 0;
 709         return 0;
 710 }
 711
 712 /*
 713  * Stop the DMA engine. Any remaining buffers in the DMA queue are dequeued
 714  * and passed on to the vb2 framework marked as STATE_ERROR.
 715  */
 716 static void sur40_stop_streaming(struct vb2_queue *vq)
 717 {
 718         struct sur40_state *sur40 = vb2_get_drv_priv(vq);
 719
 720         /* Release all active buffers */
 721         return_all_buffers(sur40, VB2_BUF_STATE_ERROR);
 722 }
 723
 724 /* V4L ioctl */
 725 static int sur40_vidioc_querycap(struct file *file, void *priv,
 726                                  struct v4l2_capability *cap)
 727 {
 728         struct sur40_state *sur40 = video_drvdata(file);
 729
 730         strlcpy(cap->driver, DRIVER_SHORT, sizeof(cap->driver));
 731         strlcpy(cap->card, DRIVER_LONG, sizeof(cap->card));
 732         usb_make_path(sur40->usbdev, cap->bus_info, sizeof(cap->bus_info));
 733         cap->device_caps = V4L2_CAP_VIDEO_CAPTURE |
 734                 V4L2_CAP_READWRITE |
 735                 V4L2_CAP_STREAMING;
 736         cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
 737         return 0;
 738 }
 739
 740 static int sur40_vidioc_enum_input(struct file *file, void *priv,
 741                                    struct v4l2_input *i)
 742 {
 743         if (i->index != 0)
 744                 return -EINVAL;
 745         i->type = V4L2_INPUT_TYPE_CAMERA;
 746         i->std = V4L2_STD_UNKNOWN;
 747         strlcpy(i->name, "In-Cell Sensor", sizeof(i->name));
 748         i->capabilities = 0;
 749         return 0;
 750 }
 751
 752 static int sur40_vidioc_s_input(struct file *file, void *priv, unsigned int i)
 753 {
 754         return (i == 0) ? 0 : -EINVAL;
 755 }
 756
 757 static int sur40_vidioc_g_input(struct file *file, void *priv, unsigned int *i)
 758 {
 759         *i = 0;
 760         return 0;
 761 }
 762
 763 static int sur40_vidioc_fmt(struct file *file, void *priv,
 764                             struct v4l2_format *f)
 765 {
 766         f->fmt.pix = sur40_video_format;
 767         return 0;
 768 }
 769
 770 static int sur40_vidioc_enum_fmt(struct file *file, void *priv,
 771                                  struct v4l2_fmtdesc *f)
 772 {
 773         if (f->index != 0)
 774                 return -EINVAL;
 775         strlcpy(f->description, "8-bit greyscale", sizeof(f->description));
 776         f->pixelformat = V4L2_PIX_FMT_GREY;
 777         f->flags = 0;
 778         return 0;
 779 }
 780
 781 static const struct usb_device_id sur40_table[] = {
 782         { USB_DEVICE(ID_MICROSOFT, ID_SUR40) },  /* Samsung SUR40 */
 783         { }                                      /* terminating null entry */
 784 };
 785 MODULE_DEVICE_TABLE(usb, sur40_table);
 786
 787 /* V4L2 structures */
 788 static const struct vb2_ops sur40_queue_ops = {
 789         .queue_setup            = sur40_queue_setup,
 790         .buf_prepare            = sur40_buffer_prepare,
 791         .buf_queue              = sur40_buffer_queue,
 792         .start_streaming        = sur40_start_streaming,
 793         .stop_streaming         = sur40_stop_streaming,
 794         .wait_prepare           = vb2_ops_wait_prepare,
 795         .wait_finish            = vb2_ops_wait_finish,
 796 };
 797
 798 static const struct vb2_queue sur40_queue = {
 799         .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
 800         /*
 801          * VB2_USERPTR in currently not enabled: passing a user pointer to
 802          * dma-sg will result in segment sizes that are not a multiple of
 803          * 512 bytes, which is required by the host controller.
 804         */
 805         .io_modes = VB2_MMAP | VB2_READ | VB2_DMABUF,
 806         .buf_struct_size = sizeof(struct sur40_buffer),
 807         .ops = &sur40_queue_ops,
 808         .mem_ops = &vb2_dma_sg_memops,
 809         .timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC,
 810         .min_buffers_needed = 3,
 811 };
 812
 813 static const struct v4l2_file_operations sur40_video_fops = {
 814         .owner = THIS_MODULE,
 815         .open = v4l2_fh_open,
 816         .release = vb2_fop_release,
 817         .unlocked_ioctl = video_ioctl2,
 818         .read = vb2_fop_read,
 819         .mmap = vb2_fop_mmap,
 820         .poll = vb2_fop_poll,
 821 };
 822
 823 static const struct v4l2_ioctl_ops sur40_video_ioctl_ops = {
 824
 825         .vidioc_querycap        = sur40_vidioc_querycap,
 826
 827         .vidioc_enum_fmt_vid_cap = sur40_vidioc_enum_fmt,
 828         .vidioc_try_fmt_vid_cap = sur40_vidioc_fmt,
 829         .vidioc_s_fmt_vid_cap   = sur40_vidioc_fmt,
 830         .vidioc_g_fmt_vid_cap   = sur40_vidioc_fmt,
 831
 832         .vidioc_enum_input      = sur40_vidioc_enum_input,
 833         .vidioc_g_input         = sur40_vidioc_g_input,
 834         .vidioc_s_input         = sur40_vidioc_s_input,
 835
 836         .vidioc_reqbufs         = vb2_ioctl_reqbufs,
 837         .vidioc_create_bufs     = vb2_ioctl_create_bufs,
 838         .vidioc_querybuf        = vb2_ioctl_querybuf,
 839         .vidioc_qbuf            = vb2_ioctl_qbuf,
 840         .vidioc_dqbuf           = vb2_ioctl_dqbuf,
 841         .vidioc_expbuf          = vb2_ioctl_expbuf,
 842
 843         .vidioc_streamon        = vb2_ioctl_streamon,
 844         .vidioc_streamoff       = vb2_ioctl_streamoff,
 845 };
 846
 847 static const struct video_device sur40_video_device = {
 848         .name = DRIVER_LONG,
 849         .fops = &sur40_video_fops,
 850         .ioctl_ops = &sur40_video_ioctl_ops,
 851         .release = video_device_release_empty,
 852 };
 853
 854 static const struct v4l2_pix_format sur40_video_format = {
 855         .pixelformat = V4L2_PIX_FMT_GREY,
 856         .width  = SENSOR_RES_X / 2,
 857         .height = SENSOR_RES_Y / 2,
 858         .field = V4L2_FIELD_NONE,
 859         .colorspace = V4L2_COLORSPACE_SRGB,
 860         .bytesperline = SENSOR_RES_X / 2,
 861         .sizeimage = (SENSOR_RES_X/2) * (SENSOR_RES_Y/2),
 862 };
 863
 864 /* USB-specific object needed to register this driver with the USB subsystem. */
 865 static struct usb_driver sur40_driver = {
 866         .name = DRIVER_SHORT,
 867         .probe = sur40_probe,
 868         .disconnect = sur40_disconnect,
 869         .id_table = sur40_table,
 870 };
 871
 872 module_usb_driver(sur40_driver);
 873
 874 MODULE_AUTHOR(DRIVER_AUTHOR);
 875 MODULE_DESCRIPTION(DRIVER_DESC);
 876 MODULE_LICENSE("GPL");