linux/drivers/input/touchscreen/sur40.c
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   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 */
  45struct 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
  57struct 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 */
  89struct 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 */
  96struct sur40_image_header {
  97        __le32 magic;     /* "SUBF" */
  98        __le32 packet_id;
  99        __le32 size;      /* always 0x0007e900 = 960x540 */
 100        __le32 timestamp; /* milliseconds (increases by 16 or 17 each frame) */
 101        __le32 unknown;   /* "epoch?" always 02/03 00 00 00 */
 102} __packed;
 103
 104/* version information */
 105#define DRIVER_SHORT   "sur40"
 106#define DRIVER_LONG    "Samsung SUR40"
 107#define DRIVER_AUTHOR  "Florian 'floe' Echtler <floe@butterbrot.org>"
 108#define DRIVER_DESC    "Surface2.0/SUR40/PixelSense input driver"
 109
 110/* vendor and device IDs */
 111#define ID_MICROSOFT 0x045e
 112#define ID_SUR40     0x0775
 113
 114/* sensor resolution */
 115#define SENSOR_RES_X 1920
 116#define SENSOR_RES_Y 1080
 117
 118/* touch data endpoint */
 119#define TOUCH_ENDPOINT 0x86
 120
 121/* video data endpoint */
 122#define VIDEO_ENDPOINT 0x82
 123
 124/* video header fields */
 125#define VIDEO_HEADER_MAGIC 0x46425553
 126#define VIDEO_PACKET_SIZE  16384
 127
 128/* polling interval (ms) */
 129#define POLL_INTERVAL 1
 130
 131/* maximum number of contacts FIXME: this is a guess? */
 132#define MAX_CONTACTS 64
 133
 134/* control commands */
 135#define SUR40_GET_VERSION 0xb0 /* 12 bytes string    */
 136#define SUR40_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 */
 143struct 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
 166struct sur40_buffer {
 167        struct vb2_v4l2_buffer vb;
 168        struct list_head list;
 169};
 170
 171/* forward declarations */
 172static const struct video_device sur40_video_device;
 173static const struct v4l2_pix_format sur40_video_format;
 174static const struct vb2_queue sur40_queue;
 175static 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 */
 187static 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 */
 197static int sur40_init(struct sur40_state *dev)
 198{
 199        int result;
 200        u8 *buffer;
 201
 202        buffer = kmalloc(24, GFP_KERNEL);
 203        if (!buffer) {
 204                result = -ENOMEM;
 205                goto error;
 206        }
 207
 208        /* stupidly replay the original MS driver init sequence */
 209        result = sur40_command(dev, SUR40_GET_VERSION, 0x00, buffer, 12);
 210        if (result < 0)
 211                goto error;
 212
 213        result = sur40_command(dev, SUR40_GET_VERSION, 0x01, buffer, 12);
 214        if (result < 0)
 215                goto error;
 216
 217        result = sur40_command(dev, SUR40_GET_VERSION, 0x02, buffer, 12);
 218        if (result < 0)
 219                goto error;
 220
 221        result = sur40_command(dev, SUR40_UNKNOWN2,    0x00, buffer, 24);
 222        if (result < 0)
 223                goto error;
 224
 225        result = sur40_command(dev, SUR40_UNKNOWN1,    0x00, buffer,  5);
 226        if (result < 0)
 227                goto error;
 228
 229        result = sur40_command(dev, SUR40_GET_VERSION, 0x03, buffer, 12);
 230
 231        /*
 232         * Discard the result buffer - no known data inside except
 233         * some version strings, maybe extract these sometime...
 234         */
 235error:
 236        kfree(buffer);
 237        return result;
 238}
 239
 240/*
 241 * Callback routines from input_polled_dev
 242 */
 243
 244/* Enable the device, polling will now start. */
 245static void sur40_open(struct input_polled_dev *polldev)
 246{
 247        struct sur40_state *sur40 = polldev->private;
 248
 249        dev_dbg(sur40->dev, "open\n");
 250        sur40_init(sur40);
 251}
 252
 253/* Disable device, polling has stopped. */
 254static void sur40_close(struct input_polled_dev *polldev)
 255{
 256        struct sur40_state *sur40 = polldev->private;
 257
 258        dev_dbg(sur40->dev, "close\n");
 259        /*
 260         * There is no known way to stop the device, so we simply
 261         * stop polling.
 262         */
 263}
 264
 265/*
 266 * This function is called when a whole contact has been processed,
 267 * so that it can assign it to a slot and store the data there.
 268 */
 269static void sur40_report_blob(struct sur40_blob *blob, struct input_dev *input)
 270{
 271        int wide, major, minor;
 272
 273        int bb_size_x = le16_to_cpu(blob->bb_size_x);
 274        int bb_size_y = le16_to_cpu(blob->bb_size_y);
 275
 276        int pos_x = le16_to_cpu(blob->pos_x);
 277        int pos_y = le16_to_cpu(blob->pos_y);
 278
 279        int ctr_x = le16_to_cpu(blob->ctr_x);
 280        int ctr_y = le16_to_cpu(blob->ctr_y);
 281
 282        int slotnum = input_mt_get_slot_by_key(input, blob->blob_id);
 283        if (slotnum < 0 || slotnum >= MAX_CONTACTS)
 284                return;
 285
 286        input_mt_slot(input, slotnum);
 287        input_mt_report_slot_state(input, MT_TOOL_FINGER, 1);
 288        wide = (bb_size_x > bb_size_y);
 289        major = max(bb_size_x, bb_size_y);
 290        minor = min(bb_size_x, bb_size_y);
 291
 292        input_report_abs(input, ABS_MT_POSITION_X, pos_x);
 293        input_report_abs(input, ABS_MT_POSITION_Y, pos_y);
 294        input_report_abs(input, ABS_MT_TOOL_X, ctr_x);
 295        input_report_abs(input, ABS_MT_TOOL_Y, ctr_y);
 296
 297        /* TODO: use a better orientation measure */
 298        input_report_abs(input, ABS_MT_ORIENTATION, wide);
 299        input_report_abs(input, ABS_MT_TOUCH_MAJOR, major);
 300        input_report_abs(input, ABS_MT_TOUCH_MINOR, minor);
 301}
 302
 303/* core function: poll for new input data */
 304static void sur40_poll(struct input_polled_dev *polldev)
 305{
 306        struct sur40_state *sur40 = polldev->private;
 307        struct input_dev *input = polldev->input;
 308        int result, bulk_read, need_blobs, packet_blobs, i;
 309        u32 uninitialized_var(packet_id);
 310
 311        struct sur40_header *header = &sur40->bulk_in_buffer->header;
 312        struct sur40_blob *inblob = &sur40->bulk_in_buffer->blobs[0];
 313
 314        dev_dbg(sur40->dev, "poll\n");
 315
 316        need_blobs = -1;
 317
 318        do {
 319
 320                /* perform a blocking bulk read to get data from the device */
 321                result = usb_bulk_msg(sur40->usbdev,
 322                        usb_rcvbulkpipe(sur40->usbdev, sur40->bulk_in_epaddr),
 323                        sur40->bulk_in_buffer, sur40->bulk_in_size,
 324                        &bulk_read, 1000);
 325
 326                dev_dbg(sur40->dev, "received %d bytes\n", bulk_read);
 327
 328                if (result < 0) {
 329                        dev_err(sur40->dev, "error in usb_bulk_read\n");
 330                        return;
 331                }
 332
 333                result = bulk_read - sizeof(struct sur40_header);
 334
 335                if (result % sizeof(struct sur40_blob) != 0) {
 336                        dev_err(sur40->dev, "transfer size mismatch\n");
 337                        return;
 338                }
 339
 340                /* first packet? */
 341                if (need_blobs == -1) {
 342                        need_blobs = le16_to_cpu(header->count);
 343                        dev_dbg(sur40->dev, "need %d blobs\n", need_blobs);
 344                        packet_id = le32_to_cpu(header->packet_id);
 345                }
 346
 347                /*
 348                 * Sanity check. when video data is also being retrieved, the
 349                 * packet ID will usually increase in the middle of a series
 350                 * instead of at the end.
 351                 */
 352                if (packet_id != header->packet_id)
 353                        dev_dbg(sur40->dev, "packet ID mismatch\n");
 354
 355                packet_blobs = result / sizeof(struct sur40_blob);
 356                dev_dbg(sur40->dev, "received %d blobs\n", packet_blobs);
 357
 358                /* packets always contain at least 4 blobs, even if empty */
 359                if (packet_blobs > need_blobs)
 360                        packet_blobs = need_blobs;
 361
 362                for (i = 0; i < packet_blobs; i++) {
 363                        need_blobs--;
 364                        dev_dbg(sur40->dev, "processing blob\n");
 365                        sur40_report_blob(&(inblob[i]), input);
 366                }
 367
 368        } while (need_blobs > 0);
 369
 370        input_mt_sync_frame(input);
 371        input_sync(input);
 372
 373        sur40_process_video(sur40);
 374}
 375
 376/* deal with video data */
 377static void sur40_process_video(struct sur40_state *sur40)
 378{
 379
 380        struct sur40_image_header *img = (void *)(sur40->bulk_in_buffer);
 381        struct sur40_buffer *new_buf;
 382        struct usb_sg_request sgr;
 383        struct sg_table *sgt;
 384        int result, bulk_read;
 385
 386        if (!vb2_start_streaming_called(&sur40->queue))
 387                return;
 388
 389        /* get a new buffer from the list */
 390        spin_lock(&sur40->qlock);
 391        if (list_empty(&sur40->buf_list)) {
 392                dev_dbg(sur40->dev, "buffer queue empty\n");
 393                spin_unlock(&sur40->qlock);
 394                return;
 395        }
 396        new_buf = list_entry(sur40->buf_list.next, struct sur40_buffer, list);
 397        list_del(&new_buf->list);
 398        spin_unlock(&sur40->qlock);
 399
 400        dev_dbg(sur40->dev, "buffer acquired\n");
 401
 402        /* retrieve data via bulk read */
 403        result = usb_bulk_msg(sur40->usbdev,
 404                        usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT),
 405                        sur40->bulk_in_buffer, sur40->bulk_in_size,
 406                        &bulk_read, 1000);
 407
 408        if (result < 0) {
 409                dev_err(sur40->dev, "error in usb_bulk_read\n");
 410                goto err_poll;
 411        }
 412
 413        if (bulk_read != sizeof(struct sur40_image_header)) {
 414                dev_err(sur40->dev, "received %d bytes (%zd expected)\n",
 415                        bulk_read, sizeof(struct sur40_image_header));
 416                goto err_poll;
 417        }
 418
 419        if (le32_to_cpu(img->magic) != VIDEO_HEADER_MAGIC) {
 420                dev_err(sur40->dev, "image magic mismatch\n");
 421                goto err_poll;
 422        }
 423
 424        if (le32_to_cpu(img->size) != sur40_video_format.sizeimage) {
 425                dev_err(sur40->dev, "image size mismatch\n");
 426                goto err_poll;
 427        }
 428
 429        dev_dbg(sur40->dev, "header acquired\n");
 430
 431        sgt = vb2_dma_sg_plane_desc(&new_buf->vb.vb2_buf, 0);
 432
 433        result = usb_sg_init(&sgr, sur40->usbdev,
 434                usb_rcvbulkpipe(sur40->usbdev, VIDEO_ENDPOINT), 0,
 435                sgt->sgl, sgt->nents, sur40_video_format.sizeimage, 0);
 436        if (result < 0) {
 437                dev_err(sur40->dev, "error %d in usb_sg_init\n", result);
 438                goto err_poll;
 439        }
 440
 441        usb_sg_wait(&sgr);
 442        if (sgr.status < 0) {
 443                dev_err(sur40->dev, "error %d in usb_sg_wait\n", sgr.status);
 444                goto err_poll;
 445        }
 446
 447        dev_dbg(sur40->dev, "image acquired\n");
 448
 449        /* return error if streaming was stopped in the meantime */
 450        if (sur40->sequence == -1)
 451                return;
 452
 453        /* mark as finished */
 454        new_buf->vb.vb2_buf.timestamp = ktime_get_ns();
 455        new_buf->vb.sequence = sur40->sequence++;
 456        new_buf->vb.field = V4L2_FIELD_NONE;
 457        vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
 458        dev_dbg(sur40->dev, "buffer marked done\n");
 459        return;
 460
 461err_poll:
 462        vb2_buffer_done(&new_buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
 463}
 464
 465/* Initialize input device parameters. */
 466static void sur40_input_setup(struct input_dev *input_dev)
 467{
 468        __set_bit(EV_KEY, input_dev->evbit);
 469        __set_bit(EV_ABS, input_dev->evbit);
 470
 471        input_set_abs_params(input_dev, ABS_MT_POSITION_X,
 472                             0, SENSOR_RES_X, 0, 0);
 473        input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
 474                             0, SENSOR_RES_Y, 0, 0);
 475
 476        input_set_abs_params(input_dev, ABS_MT_TOOL_X,
 477                             0, SENSOR_RES_X, 0, 0);
 478        input_set_abs_params(input_dev, ABS_MT_TOOL_Y,
 479                             0, SENSOR_RES_Y, 0, 0);
 480
 481        /* max value unknown, but major/minor axis
 482         * can never be larger than screen */
 483        input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
 484                             0, SENSOR_RES_X, 0, 0);
 485        input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR,
 486                             0, SENSOR_RES_Y, 0, 0);
 487
 488        input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
 489
 490        input_mt_init_slots(input_dev, MAX_CONTACTS,
 491                            INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
 492}
 493
 494/* Check candidate USB interface. */
 495static int sur40_probe(struct usb_interface *interface,
 496                       const struct usb_device_id *id)
 497{
 498        struct usb_device *usbdev = interface_to_usbdev(interface);
 499        struct sur40_state *sur40;
 500        struct usb_host_interface *iface_desc;
 501        struct usb_endpoint_descriptor *endpoint;
 502        struct input_polled_dev *poll_dev;
 503        int error;
 504
 505        /* Check if we really have the right interface. */
 506        iface_desc = &interface->altsetting[0];
 507        if (iface_desc->desc.bInterfaceClass != 0xFF)
 508                return -ENODEV;
 509
 510        /* Use endpoint #4 (0x86). */
 511        endpoint = &iface_desc->endpoint[4].desc;
 512        if (endpoint->bEndpointAddress != TOUCH_ENDPOINT)
 513                return -ENODEV;
 514
 515        /* Allocate memory for our device state and initialize it. */
 516        sur40 = kzalloc(sizeof(struct sur40_state), GFP_KERNEL);
 517        if (!sur40)
 518                return -ENOMEM;
 519
 520        poll_dev = input_allocate_polled_device();
 521        if (!poll_dev) {
 522                error = -ENOMEM;
 523                goto err_free_dev;
 524        }
 525
 526        /* initialize locks/lists */
 527        INIT_LIST_HEAD(&sur40->buf_list);
 528        spin_lock_init(&sur40->qlock);
 529        mutex_init(&sur40->lock);
 530
 531        /* Set up polled input device control structure */
 532        poll_dev->private = sur40;
 533        poll_dev->poll_interval = POLL_INTERVAL;
 534        poll_dev->open = sur40_open;
 535        poll_dev->poll = sur40_poll;
 536        poll_dev->close = sur40_close;
 537
 538        /* Set up regular input device structure */
 539        sur40_input_setup(poll_dev->input);
 540
 541        poll_dev->input->name = DRIVER_LONG;
 542        usb_to_input_id(usbdev, &poll_dev->input->id);
 543        usb_make_path(usbdev, sur40->phys, sizeof(sur40->phys));
 544        strlcat(sur40->phys, "/input0", sizeof(sur40->phys));
 545        poll_dev->input->phys = sur40->phys;
 546        poll_dev->input->dev.parent = &interface->dev;
 547
 548        sur40->usbdev = usbdev;
 549        sur40->dev = &interface->dev;
 550        sur40->input = poll_dev;
 551
 552        /* use the bulk-in endpoint tested above */
 553        sur40->bulk_in_size = usb_endpoint_maxp(endpoint);
 554        sur40->bulk_in_epaddr = endpoint->bEndpointAddress;
 555        sur40->bulk_in_buffer = kmalloc(sur40->bulk_in_size, GFP_KERNEL);
 556        if (!sur40->bulk_in_buffer) {
 557                dev_err(&interface->dev, "Unable to allocate input buffer.");
 558                error = -ENOMEM;
 559                goto err_free_polldev;
 560        }
 561
 562        /* register the polled input device */
 563        error = input_register_polled_device(poll_dev);
 564        if (error) {
 565                dev_err(&interface->dev,
 566                        "Unable to register polled input device.");
 567                goto err_free_buffer;
 568        }
 569
 570        /* register the video master device */
 571        snprintf(sur40->v4l2.name, sizeof(sur40->v4l2.name), "%s", DRIVER_LONG);
 572        error = v4l2_device_register(sur40->dev, &sur40->v4l2);
 573        if (error) {
 574                dev_err(&interface->dev,
 575                        "Unable to register video master device.");
 576                goto err_unreg_v4l2;
 577        }
 578
 579        /* initialize the lock and subdevice */
 580        sur40->queue = sur40_queue;
 581        sur40->queue.drv_priv = sur40;
 582        sur40->queue.lock = &sur40->lock;
 583
 584        /* initialize the queue */
 585        error = vb2_queue_init(&sur40->queue);
 586        if (error)
 587                goto err_unreg_v4l2;
 588
 589        sur40->alloc_ctx = vb2_dma_sg_init_ctx(sur40->dev);
 590        if (IS_ERR(sur40->alloc_ctx)) {
 591                dev_err(sur40->dev, "Can't allocate buffer context");
 592                error = PTR_ERR(sur40->alloc_ctx);
 593                goto err_unreg_v4l2;
 594        }
 595
 596        sur40->vdev = sur40_video_device;
 597        sur40->vdev.v4l2_dev = &sur40->v4l2;
 598        sur40->vdev.lock = &sur40->lock;
 599        sur40->vdev.queue = &sur40->queue;
 600        video_set_drvdata(&sur40->vdev, sur40);
 601
 602        error = video_register_device(&sur40->vdev, VFL_TYPE_GRABBER, -1);
 603        if (error) {
 604                dev_err(&interface->dev,
 605                        "Unable to register video subdevice.");
 606                goto err_unreg_video;
 607        }
 608
 609        /* we can register the device now, as it is ready */
 610        usb_set_intfdata(interface, sur40);
 611        dev_dbg(&interface->dev, "%s is now attached\n", DRIVER_DESC);
 612
 613        return 0;
 614
 615err_unreg_video:
 616        video_unregister_device(&sur40->vdev);
 617err_unreg_v4l2:
 618        v4l2_device_unregister(&sur40->v4l2);
 619err_free_buffer:
 620        kfree(sur40->bulk_in_buffer);
 621err_free_polldev:
 622        input_free_polled_device(sur40->input);
 623err_free_dev:
 624        kfree(sur40);
 625
 626        return error;
 627}
 628
 629/* Unregister device & clean up. */
 630static void sur40_disconnect(struct usb_interface *interface)
 631{
 632        struct sur40_state *sur40 = usb_get_intfdata(interface);
 633
 634        video_unregister_device(&sur40->vdev);
 635        v4l2_device_unregister(&sur40->v4l2);
 636        vb2_dma_sg_cleanup_ctx(sur40->alloc_ctx);
 637
 638        input_unregister_polled_device(sur40->input);
 639        input_free_polled_device(sur40->input);
 640        kfree(sur40->bulk_in_buffer);
 641        kfree(sur40);
 642
 643        usb_set_intfdata(interface, NULL);
 644        dev_dbg(&interface->dev, "%s is now disconnected\n", DRIVER_DESC);
 645}
 646
 647/*
 648 * Setup the constraints of the queue: besides setting the number of planes
 649 * per buffer and the size and allocation context of each plane, it also
 650 * checks if sufficient buffers have been allocated. Usually 3 is a good
 651 * minimum number: many DMA engines need a minimum of 2 buffers in the
 652 * queue and you need to have another available for userspace processing.
 653 */
 654static int sur40_queue_setup(struct vb2_queue *q,
 655                       unsigned int *nbuffers, unsigned int *nplanes,
 656                       unsigned int sizes[], void *alloc_ctxs[])
 657{
 658        struct sur40_state *sur40 = vb2_get_drv_priv(q);
 659
 660        if (q->num_buffers + *nbuffers < 3)
 661                *nbuffers = 3 - q->num_buffers;
 662        alloc_ctxs[0] = sur40->alloc_ctx;
 663
 664        if (*nplanes)
 665                return sizes[0] < sur40_video_format.sizeimage ? -EINVAL : 0;
 666
 667        *nplanes = 1;
 668        sizes[0] = sur40_video_format.sizeimage;
 669
 670        return 0;
 671}
 672
 673/*
 674 * Prepare the buffer for queueing to the DMA engine: check and set the
 675 * payload size.
 676 */
 677static int sur40_buffer_prepare(struct vb2_buffer *vb)
 678{
 679        struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
 680        unsigned long size = sur40_video_format.sizeimage;
 681
 682        if (vb2_plane_size(vb, 0) < size) {
 683                dev_err(&sur40->usbdev->dev, "buffer too small (%lu < %lu)\n",
 684                         vb2_plane_size(vb, 0), size);
 685                return -EINVAL;
 686        }
 687
 688        vb2_set_plane_payload(vb, 0, size);
 689        return 0;
 690}
 691
 692/*
 693 * Queue this buffer to the DMA engine.
 694 */
 695static void sur40_buffer_queue(struct vb2_buffer *vb)
 696{
 697        struct sur40_state *sur40 = vb2_get_drv_priv(vb->vb2_queue);
 698        struct sur40_buffer *buf = (struct sur40_buffer *)vb;
 699
 700        spin_lock(&sur40->qlock);
 701        list_add_tail(&buf->list, &sur40->buf_list);
 702        spin_unlock(&sur40->qlock);
 703}
 704
 705static void return_all_buffers(struct sur40_state *sur40,
 706                               enum vb2_buffer_state state)
 707{
 708        struct sur40_buffer *buf, *node;
 709
 710        spin_lock(&sur40->qlock);
 711        list_for_each_entry_safe(buf, node, &sur40->buf_list, list) {
 712                vb2_buffer_done(&buf->vb.vb2_buf, state);
 713                list_del(&buf->list);
 714        }
 715        spin_unlock(&sur40->qlock);
 716}
 717
 718/*
 719 * Start streaming. First check if the minimum number of buffers have been
 720 * queued. If not, then return -ENOBUFS and the vb2 framework will call
 721 * this function again the next time a buffer has been queued until enough
 722 * buffers are available to actually start the DMA engine.
 723 */
 724static int sur40_start_streaming(struct vb2_queue *vq, unsigned int count)
 725{
 726        struct sur40_state *sur40 = vb2_get_drv_priv(vq);
 727
 728        sur40->sequence = 0;
 729        return 0;
 730}
 731
 732/*
 733 * Stop the DMA engine. Any remaining buffers in the DMA queue are dequeued
 734 * and passed on to the vb2 framework marked as STATE_ERROR.
 735 */
 736static void sur40_stop_streaming(struct vb2_queue *vq)
 737{
 738        struct sur40_state *sur40 = vb2_get_drv_priv(vq);
 739        vb2_wait_for_all_buffers(vq);
 740        sur40->sequence = -1;
 741
 742        /* Release all active buffers */
 743        return_all_buffers(sur40, VB2_BUF_STATE_ERROR);
 744}
 745
 746/* V4L ioctl */
 747static int sur40_vidioc_querycap(struct file *file, void *priv,
 748                                 struct v4l2_capability *cap)
 749{
 750        struct sur40_state *sur40 = video_drvdata(file);
 751
 752        strlcpy(cap->driver, DRIVER_SHORT, sizeof(cap->driver));
 753        strlcpy(cap->card, DRIVER_LONG, sizeof(cap->card));
 754        usb_make_path(sur40->usbdev, cap->bus_info, sizeof(cap->bus_info));
 755        cap->device_caps = V4L2_CAP_VIDEO_CAPTURE |
 756                V4L2_CAP_READWRITE |
 757                V4L2_CAP_STREAMING;
 758        cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
 759        return 0;
 760}
 761
 762static int sur40_vidioc_enum_input(struct file *file, void *priv,
 763                                   struct v4l2_input *i)
 764{
 765        if (i->index != 0)
 766                return -EINVAL;
 767        i->type = V4L2_INPUT_TYPE_CAMERA;
 768        i->std = V4L2_STD_UNKNOWN;
 769        strlcpy(i->name, "In-Cell Sensor", sizeof(i->name));
 770        i->capabilities = 0;
 771        return 0;
 772}
 773
 774static int sur40_vidioc_s_input(struct file *file, void *priv, unsigned int i)
 775{
 776        return (i == 0) ? 0 : -EINVAL;
 777}
 778
 779static int sur40_vidioc_g_input(struct file *file, void *priv, unsigned int *i)
 780{
 781        *i = 0;
 782        return 0;
 783}
 784
 785static int sur40_vidioc_fmt(struct file *file, void *priv,
 786                            struct v4l2_format *f)
 787{
 788        f->fmt.pix = sur40_video_format;
 789        return 0;
 790}
 791
 792static int sur40_vidioc_enum_fmt(struct file *file, void *priv,
 793                                 struct v4l2_fmtdesc *f)
 794{
 795        if (f->index != 0)
 796                return -EINVAL;
 797        strlcpy(f->description, "8-bit greyscale", sizeof(f->description));
 798        f->pixelformat = V4L2_PIX_FMT_GREY;
 799        f->flags = 0;
 800        return 0;
 801}
 802
 803static int sur40_vidioc_enum_framesizes(struct file *file, void *priv,
 804                                        struct v4l2_frmsizeenum *f)
 805{
 806        if ((f->index != 0) || (f->pixel_format != V4L2_PIX_FMT_GREY))
 807                return -EINVAL;
 808
 809        f->type = V4L2_FRMSIZE_TYPE_DISCRETE;
 810        f->discrete.width  = sur40_video_format.width;
 811        f->discrete.height = sur40_video_format.height;
 812        return 0;
 813}
 814
 815static int sur40_vidioc_enum_frameintervals(struct file *file, void *priv,
 816                                            struct v4l2_frmivalenum *f)
 817{
 818        if ((f->index > 1) || (f->pixel_format != V4L2_PIX_FMT_GREY)
 819                || (f->width  != sur40_video_format.width)
 820                || (f->height != sur40_video_format.height))
 821                        return -EINVAL;
 822
 823        f->type = V4L2_FRMIVAL_TYPE_DISCRETE;
 824        f->discrete.denominator  = 60/(f->index+1);
 825        f->discrete.numerator = 1;
 826        return 0;
 827}
 828
 829
 830static const struct usb_device_id sur40_table[] = {
 831        { USB_DEVICE(ID_MICROSOFT, ID_SUR40) },  /* Samsung SUR40 */
 832        { }                                      /* terminating null entry */
 833};
 834MODULE_DEVICE_TABLE(usb, sur40_table);
 835
 836/* V4L2 structures */
 837static const struct vb2_ops sur40_queue_ops = {
 838        .queue_setup            = sur40_queue_setup,
 839        .buf_prepare            = sur40_buffer_prepare,
 840        .buf_queue              = sur40_buffer_queue,
 841        .start_streaming        = sur40_start_streaming,
 842        .stop_streaming         = sur40_stop_streaming,
 843        .wait_prepare           = vb2_ops_wait_prepare,
 844        .wait_finish            = vb2_ops_wait_finish,
 845};
 846
 847static const struct vb2_queue sur40_queue = {
 848        .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
 849        /*
 850         * VB2_USERPTR in currently not enabled: passing a user pointer to
 851         * dma-sg will result in segment sizes that are not a multiple of
 852         * 512 bytes, which is required by the host controller.
 853        */
 854        .io_modes = VB2_MMAP | VB2_READ | VB2_DMABUF,
 855        .buf_struct_size = sizeof(struct sur40_buffer),
 856        .ops = &sur40_queue_ops,
 857        .mem_ops = &vb2_dma_sg_memops,
 858        .timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC,
 859        .min_buffers_needed = 3,
 860};
 861
 862static const struct v4l2_file_operations sur40_video_fops = {
 863        .owner = THIS_MODULE,
 864        .open = v4l2_fh_open,
 865        .release = vb2_fop_release,
 866        .unlocked_ioctl = video_ioctl2,
 867        .read = vb2_fop_read,
 868        .mmap = vb2_fop_mmap,
 869        .poll = vb2_fop_poll,
 870};
 871
 872static const struct v4l2_ioctl_ops sur40_video_ioctl_ops = {
 873
 874        .vidioc_querycap        = sur40_vidioc_querycap,
 875
 876        .vidioc_enum_fmt_vid_cap = sur40_vidioc_enum_fmt,
 877        .vidioc_try_fmt_vid_cap = sur40_vidioc_fmt,
 878        .vidioc_s_fmt_vid_cap   = sur40_vidioc_fmt,
 879        .vidioc_g_fmt_vid_cap   = sur40_vidioc_fmt,
 880
 881        .vidioc_enum_framesizes = sur40_vidioc_enum_framesizes,
 882        .vidioc_enum_frameintervals = sur40_vidioc_enum_frameintervals,
 883
 884        .vidioc_enum_input      = sur40_vidioc_enum_input,
 885        .vidioc_g_input         = sur40_vidioc_g_input,
 886        .vidioc_s_input         = sur40_vidioc_s_input,
 887
 888        .vidioc_reqbufs         = vb2_ioctl_reqbufs,
 889        .vidioc_create_bufs     = vb2_ioctl_create_bufs,
 890        .vidioc_querybuf        = vb2_ioctl_querybuf,
 891        .vidioc_qbuf            = vb2_ioctl_qbuf,
 892        .vidioc_dqbuf           = vb2_ioctl_dqbuf,
 893        .vidioc_expbuf          = vb2_ioctl_expbuf,
 894
 895        .vidioc_streamon        = vb2_ioctl_streamon,
 896        .vidioc_streamoff       = vb2_ioctl_streamoff,
 897};
 898
 899static const struct video_device sur40_video_device = {
 900        .name = DRIVER_LONG,
 901        .fops = &sur40_video_fops,
 902        .ioctl_ops = &sur40_video_ioctl_ops,
 903        .release = video_device_release_empty,
 904};
 905
 906static const struct v4l2_pix_format sur40_video_format = {
 907        .pixelformat = V4L2_PIX_FMT_GREY,
 908        .width  = SENSOR_RES_X / 2,
 909        .height = SENSOR_RES_Y / 2,
 910        .field = V4L2_FIELD_NONE,
 911        .colorspace = V4L2_COLORSPACE_SRGB,
 912        .bytesperline = SENSOR_RES_X / 2,
 913        .sizeimage = (SENSOR_RES_X/2) * (SENSOR_RES_Y/2),
 914};
 915
 916/* USB-specific object needed to register this driver with the USB subsystem. */
 917static struct usb_driver sur40_driver = {
 918        .name = DRIVER_SHORT,
 919        .probe = sur40_probe,
 920        .disconnect = sur40_disconnect,
 921        .id_table = sur40_table,
 922};
 923
 924module_usb_driver(sur40_driver);
 925
 926MODULE_AUTHOR(DRIVER_AUTHOR);
 927MODULE_DESCRIPTION(DRIVER_DESC);
 928MODULE_LICENSE("GPL");
 929
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