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-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         v4l2_get_timestamp(&new_buf->vb.timestamp);
 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, const void *parg,
 648                        unsigned int *nbuffers, unsigned int *nplanes,
 649                        unsigned int sizes[], void *alloc_ctxs[])
 650 {
 651         const struct v4l2_format *fmt = parg;
 652         struct sur40_state *sur40 = vb2_get_drv_priv(q);
 653
 654         if (q->num_buffers + *nbuffers < 3)
 655                 *nbuffers = 3 - q->num_buffers;
 656
 657         if (fmt && fmt->fmt.pix.sizeimage < sur40_video_format.sizeimage)
 658                 return -EINVAL;
 659
 660         *nplanes = 1;
 661         sizes[0] = fmt ? fmt->fmt.pix.sizeimage : sur40_video_format.sizeimage;
 662         alloc_ctxs[0] = sur40->alloc_ctx;
 663
 664         return 0;
 665 }
 666
 667 /*
 668  * Prepare the buffer for queueing to the DMA engine: check and set the
 669  * payload size.
 670  */
 671 static int sur40_buffer_prepare(struct vb2_buffer *vb)
 672 {
 673         struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
 674         unsigned long size = sur40_video_format.sizeimage;
 675
 676         if (vb2_plane_size(vb, 0) < size) {
 677                 dev_err(&sur40->usbdev->dev, "buffer too small (%lu < %lu)\n",
 678                          vb2_plane_size(vb, 0), size);
 679                 return -EINVAL;
 680         }
 681
 682         vb2_set_plane_payload(vb, 0, size);
 683         return 0;
 684 }
 685
 686 /*
 687  * Queue this buffer to the DMA engine.
 688  */
 689 static void sur40_buffer_queue(struct vb2_buffer *vb)
 690 {
 691         struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
 692         struct sur40_buffer *buf = (struct sur40_buffer *)vb;
 693
 694         spin_lock(&sur40->qlock);
 695         list_add_tail(&buf->list, &sur40->buf_list);
 696         spin_unlock(&sur40->qlock);
 697 }
 698
 699 static void return_all_buffers(struct sur40_state *sur40,
 700                                enum vb2_buffer_state state)
 701 {
 702         struct sur40_buffer *buf, *node;
 703
 704         spin_lock(&sur40->qlock);
 705         list_for_each_entry_safe(buf, node, &sur40->buf_list, list) {
 706                 vb2_buffer_done(&buf->vb.vb2_buf, state);
 707                 list_del(&buf->list);
 708         }
 709         spin_unlock(&sur40->qlock);
 710 }
 711
 712 /*
 713  * Start streaming. First check if the minimum number of buffers have been
 714  * queued. If not, then return -ENOBUFS and the vb2 framework will call
 715  * this function again the next time a buffer has been queued until enough
 716  * buffers are available to actually start the DMA engine.
 717  */
 718 static int sur40_start_streaming(struct vb2_queue *vq, unsigned int count)
 719 {
 720         struct sur40_state *sur40 = vb2_get_drv_priv(vq);
 721
 722         sur40->sequence = 0;
 723         return 0;
 724 }
 725
 726 /*
 727  * Stop the DMA engine. Any remaining buffers in the DMA queue are dequeued
 728  * and passed on to the vb2 framework marked as STATE_ERROR.
 729  */
 730 static void sur40_stop_streaming(struct vb2_queue *vq)
 731 {
 732         struct sur40_state *sur40 = vb2_get_drv_priv(vq);
 733         sur40->sequence = -1;
 734
 735         /* Release all active buffers */
 736         return_all_buffers(sur40, VB2_BUF_STATE_ERROR);
 737 }
 738
 739 /* V4L ioctl */
 740 static int sur40_vidioc_querycap(struct file *file, void *priv,
 741                                  struct v4l2_capability *cap)
 742 {
 743         struct sur40_state *sur40 = video_drvdata(file);
 744
 745         strlcpy(cap->driver, DRIVER_SHORT, sizeof(cap->driver));
 746         strlcpy(cap->card, DRIVER_LONG, sizeof(cap->card));
 747         usb_make_path(sur40->usbdev, cap->bus_info, sizeof(cap->bus_info));
 748         cap->device_caps = V4L2_CAP_VIDEO_CAPTURE |
 749                 V4L2_CAP_READWRITE |
 750                 V4L2_CAP_STREAMING;
 751         cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
 752         return 0;
 753 }
 754
 755 static int sur40_vidioc_enum_input(struct file *file, void *priv,
 756                                    struct v4l2_input *i)
 757 {
 758         if (i->index != 0)
 759                 return -EINVAL;
 760         i->type = V4L2_INPUT_TYPE_CAMERA;
 761         i->std = V4L2_STD_UNKNOWN;
 762         strlcpy(i->name, "In-Cell Sensor", sizeof(i->name));
 763         i->capabilities = 0;
 764         return 0;
 765 }
 766
 767 static int sur40_vidioc_s_input(struct file *file, void *priv, unsigned int i)
 768 {
 769         return (i == 0) ? 0 : -EINVAL;
 770 }
 771
 772 static int sur40_vidioc_g_input(struct file *file, void *priv, unsigned int *i)
 773 {
 774         *i = 0;
 775         return 0;
 776 }
 777
 778 static int sur40_vidioc_fmt(struct file *file, void *priv,
 779                             struct v4l2_format *f)
 780 {
 781         f->fmt.pix = sur40_video_format;
 782         return 0;
 783 }
 784
 785 static int sur40_vidioc_enum_fmt(struct file *file, void *priv,
 786                                  struct v4l2_fmtdesc *f)
 787 {
 788         if (f->index != 0)
 789                 return -EINVAL;
 790         strlcpy(f->description, "8-bit greyscale", sizeof(f->description));
 791         f->pixelformat = V4L2_PIX_FMT_GREY;
 792         f->flags = 0;
 793         return 0;
 794 }
 795
 796 static int sur40_vidioc_enum_framesizes(struct file *file, void *priv,
 797                                         struct v4l2_frmsizeenum *f)
 798 {
 799         if ((f->index != 0) || (f->pixel_format != V4L2_PIX_FMT_GREY))
 800                 return -EINVAL;
 801
 802         f->type = V4L2_FRMSIZE_TYPE_DISCRETE;
 803         f->discrete.width  = sur40_video_format.width;
 804         f->discrete.height = sur40_video_format.height;
 805         return 0;
 806 }
 807
 808 static int sur40_vidioc_enum_frameintervals(struct file *file, void *priv,
 809                                             struct v4l2_frmivalenum *f)
 810 {
 811         if ((f->index > 1) || (f->pixel_format != V4L2_PIX_FMT_GREY)
 812                 || (f->width  != sur40_video_format.width)
 813                 || (f->height != sur40_video_format.height))
 814                         return -EINVAL;
 815
 816         f->type = V4L2_FRMIVAL_TYPE_DISCRETE;
 817         f->discrete.denominator  = 60/(f->index+1);
 818         f->discrete.numerator = 1;
 819         return 0;
 820 }
 821
 822
 823 static const struct usb_device_id sur40_table[] = {
 824         { USB_DEVICE(ID_MICROSOFT, ID_SUR40) },  /* Samsung SUR40 */
 825         { }                                      /* terminating null entry */
 826 };
 827 MODULE_DEVICE_TABLE(usb, sur40_table);
 828
 829 /* V4L2 structures */
 830 static const struct vb2_ops sur40_queue_ops = {
 831         .queue_setup            = sur40_queue_setup,
 832         .buf_prepare            = sur40_buffer_prepare,
 833         .buf_queue              = sur40_buffer_queue,
 834         .start_streaming        = sur40_start_streaming,
 835         .stop_streaming         = sur40_stop_streaming,
 836         .wait_prepare           = vb2_ops_wait_prepare,
 837         .wait_finish            = vb2_ops_wait_finish,
 838 };
 839
 840 static const struct vb2_queue sur40_queue = {
 841         .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
 842         /*
 843          * VB2_USERPTR in currently not enabled: passing a user pointer to
 844          * dma-sg will result in segment sizes that are not a multiple of
 845          * 512 bytes, which is required by the host controller.
 846         */
 847         .io_modes = VB2_MMAP | VB2_READ | VB2_DMABUF,
 848         .buf_struct_size = sizeof(struct sur40_buffer),
 849         .ops = &sur40_queue_ops,
 850         .mem_ops = &vb2_dma_sg_memops,
 851         .timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC,
 852         .min_buffers_needed = 3,
 853 };
 854
 855 static const struct v4l2_file_operations sur40_video_fops = {
 856         .owner = THIS_MODULE,
 857         .open = v4l2_fh_open,
 858         .release = vb2_fop_release,
 859         .unlocked_ioctl = video_ioctl2,
 860         .read = vb2_fop_read,
 861         .mmap = vb2_fop_mmap,
 862         .poll = vb2_fop_poll,
 863 };
 864
 865 static const struct v4l2_ioctl_ops sur40_video_ioctl_ops = {
 866
 867         .vidioc_querycap        = sur40_vidioc_querycap,
 868
 869         .vidioc_enum_fmt_vid_cap = sur40_vidioc_enum_fmt,
 870         .vidioc_try_fmt_vid_cap = sur40_vidioc_fmt,
 871         .vidioc_s_fmt_vid_cap   = sur40_vidioc_fmt,
 872         .vidioc_g_fmt_vid_cap   = sur40_vidioc_fmt,
 873
 874         .vidioc_enum_framesizes = sur40_vidioc_enum_framesizes,
 875         .vidioc_enum_frameintervals = sur40_vidioc_enum_frameintervals,
 876
 877         .vidioc_enum_input      = sur40_vidioc_enum_input,
 878         .vidioc_g_input         = sur40_vidioc_g_input,
 879         .vidioc_s_input         = sur40_vidioc_s_input,
 880
 881         .vidioc_reqbufs         = vb2_ioctl_reqbufs,
 882         .vidioc_create_bufs     = vb2_ioctl_create_bufs,
 883         .vidioc_querybuf        = vb2_ioctl_querybuf,
 884         .vidioc_qbuf            = vb2_ioctl_qbuf,
 885         .vidioc_dqbuf           = vb2_ioctl_dqbuf,
 886         .vidioc_expbuf          = vb2_ioctl_expbuf,
 887
 888         .vidioc_streamon        = vb2_ioctl_streamon,
 889         .vidioc_streamoff       = vb2_ioctl_streamoff,
 890 };
 891
 892 static const struct video_device sur40_video_device = {
 893         .name = DRIVER_LONG,
 894         .fops = &sur40_video_fops,
 895         .ioctl_ops = &sur40_video_ioctl_ops,
 896         .release = video_device_release_empty,
 897 };
 898
 899 static const struct v4l2_pix_format sur40_video_format = {
 900         .pixelformat = V4L2_PIX_FMT_GREY,
 901         .width  = SENSOR_RES_X / 2,
 902         .height = SENSOR_RES_Y / 2,
 903         .field = V4L2_FIELD_NONE,
 904         .colorspace = V4L2_COLORSPACE_SRGB,
 905         .bytesperline = SENSOR_RES_X / 2,
 906         .sizeimage = (SENSOR_RES_X/2) * (SENSOR_RES_Y/2),
 907 };
 908
 909 /* USB-specific object needed to register this driver with the USB subsystem. */
 910 static struct usb_driver sur40_driver = {
 911         .name = DRIVER_SHORT,
 912         .probe = sur40_probe,
 913         .disconnect = sur40_disconnect,
 914         .id_table = sur40_table,
 915 };
 916
 917 module_usb_driver(sur40_driver);
 918
 919 MODULE_AUTHOR(DRIVER_AUTHOR);
 920 MODULE_DESCRIPTION(DRIVER_DESC);
 921 MODULE_LICENSE("GPL");