linux/drivers/input/touchscreen/wacom_w8001.c
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   1/*
   2 * Wacom W8001 penabled serial touchscreen driver
   3 *
   4 * Copyright (c) 2008 Jaya Kumar
   5 * Copyright (c) 2010 Red Hat, Inc.
   6 * Copyright (c) 2010 - 2011 Ping Cheng, Wacom. <pingc@wacom.com>
   7 *
   8 * This file is subject to the terms and conditions of the GNU General Public
   9 * License. See the file COPYING in the main directory of this archive for
  10 * more details.
  11 *
  12 * Layout based on Elo serial touchscreen driver by Vojtech Pavlik
  13 */
  14
  15#include <linux/errno.h>
  16#include <linux/kernel.h>
  17#include <linux/module.h>
  18#include <linux/slab.h>
  19#include <linux/input/mt.h>
  20#include <linux/serio.h>
  21#include <linux/ctype.h>
  22#include <linux/delay.h>
  23
  24#define DRIVER_DESC     "Wacom W8001 serial touchscreen driver"
  25
  26MODULE_AUTHOR("Jaya Kumar <jayakumar.lkml@gmail.com>");
  27MODULE_DESCRIPTION(DRIVER_DESC);
  28MODULE_LICENSE("GPL");
  29
  30#define W8001_MAX_LENGTH        11
  31#define W8001_LEAD_MASK         0x80
  32#define W8001_LEAD_BYTE         0x80
  33#define W8001_TAB_MASK          0x40
  34#define W8001_TAB_BYTE          0x40
  35/* set in first byte of touch data packets */
  36#define W8001_TOUCH_MASK        (0x10 | W8001_LEAD_MASK)
  37#define W8001_TOUCH_BYTE        (0x10 | W8001_LEAD_BYTE)
  38
  39#define W8001_QUERY_PACKET      0x20
  40
  41#define W8001_CMD_STOP          '0'
  42#define W8001_CMD_START         '1'
  43#define W8001_CMD_QUERY         '*'
  44#define W8001_CMD_TOUCHQUERY    '%'
  45
  46/* length of data packets in bytes, depends on device. */
  47#define W8001_PKTLEN_TOUCH93    5
  48#define W8001_PKTLEN_TOUCH9A    7
  49#define W8001_PKTLEN_TPCPEN     9
  50#define W8001_PKTLEN_TPCCTL     11      /* control packet */
  51#define W8001_PKTLEN_TOUCH2FG   13
  52
  53/* resolution in points/mm */
  54#define W8001_PEN_RESOLUTION    100
  55#define W8001_TOUCH_RESOLUTION  10
  56
  57struct w8001_coord {
  58        u8 rdy;
  59        u8 tsw;
  60        u8 f1;
  61        u8 f2;
  62        u16 x;
  63        u16 y;
  64        u16 pen_pressure;
  65        u8 tilt_x;
  66        u8 tilt_y;
  67};
  68
  69/* touch query reply packet */
  70struct w8001_touch_query {
  71        u16 x;
  72        u16 y;
  73        u8 panel_res;
  74        u8 capacity_res;
  75        u8 sensor_id;
  76};
  77
  78/*
  79 * Per-touchscreen data.
  80 */
  81
  82struct w8001 {
  83        struct input_dev *dev;
  84        struct serio *serio;
  85        struct completion cmd_done;
  86        int id;
  87        int idx;
  88        unsigned char response_type;
  89        unsigned char response[W8001_MAX_LENGTH];
  90        unsigned char data[W8001_MAX_LENGTH];
  91        char phys[32];
  92        int type;
  93        unsigned int pktlen;
  94        u16 max_touch_x;
  95        u16 max_touch_y;
  96        u16 max_pen_x;
  97        u16 max_pen_y;
  98        char name[64];
  99};
 100
 101static void parse_pen_data(u8 *data, struct w8001_coord *coord)
 102{
 103        memset(coord, 0, sizeof(*coord));
 104
 105        coord->rdy = data[0] & 0x20;
 106        coord->tsw = data[0] & 0x01;
 107        coord->f1 = data[0] & 0x02;
 108        coord->f2 = data[0] & 0x04;
 109
 110        coord->x = (data[1] & 0x7F) << 9;
 111        coord->x |= (data[2] & 0x7F) << 2;
 112        coord->x |= (data[6] & 0x60) >> 5;
 113
 114        coord->y = (data[3] & 0x7F) << 9;
 115        coord->y |= (data[4] & 0x7F) << 2;
 116        coord->y |= (data[6] & 0x18) >> 3;
 117
 118        coord->pen_pressure = data[5] & 0x7F;
 119        coord->pen_pressure |= (data[6] & 0x07) << 7 ;
 120
 121        coord->tilt_x = data[7] & 0x7F;
 122        coord->tilt_y = data[8] & 0x7F;
 123}
 124
 125static void parse_single_touch(u8 *data, struct w8001_coord *coord)
 126{
 127        coord->x = (data[1] << 7) | data[2];
 128        coord->y = (data[3] << 7) | data[4];
 129        coord->tsw = data[0] & 0x01;
 130}
 131
 132static void scale_touch_coordinates(struct w8001 *w8001,
 133                                    unsigned int *x, unsigned int *y)
 134{
 135        if (w8001->max_pen_x && w8001->max_touch_x)
 136                *x = *x * w8001->max_pen_x / w8001->max_touch_x;
 137
 138        if (w8001->max_pen_y && w8001->max_touch_y)
 139                *y = *y * w8001->max_pen_y / w8001->max_touch_y;
 140}
 141
 142static void parse_multi_touch(struct w8001 *w8001)
 143{
 144        struct input_dev *dev = w8001->dev;
 145        unsigned char *data = w8001->data;
 146        unsigned int x, y;
 147        int i;
 148        int count = 0;
 149
 150        for (i = 0; i < 2; i++) {
 151                bool touch = data[0] & (1 << i);
 152
 153                input_mt_slot(dev, i);
 154                input_mt_report_slot_state(dev, MT_TOOL_FINGER, touch);
 155                if (touch) {
 156                        x = (data[6 * i + 1] << 7) | data[6 * i + 2];
 157                        y = (data[6 * i + 3] << 7) | data[6 * i + 4];
 158                        /* data[5,6] and [11,12] is finger capacity */
 159
 160                        /* scale to pen maximum */
 161                        scale_touch_coordinates(w8001, &x, &y);
 162
 163                        input_report_abs(dev, ABS_MT_POSITION_X, x);
 164                        input_report_abs(dev, ABS_MT_POSITION_Y, y);
 165                        count++;
 166                }
 167        }
 168
 169        /* emulate single touch events when stylus is out of proximity.
 170         * This is to make single touch backward support consistent
 171         * across all Wacom single touch devices.
 172         */
 173        if (w8001->type != BTN_TOOL_PEN &&
 174                            w8001->type != BTN_TOOL_RUBBER) {
 175                w8001->type = count == 1 ? BTN_TOOL_FINGER : KEY_RESERVED;
 176                input_mt_report_pointer_emulation(dev, true);
 177        }
 178
 179        input_sync(dev);
 180}
 181
 182static void parse_touchquery(u8 *data, struct w8001_touch_query *query)
 183{
 184        memset(query, 0, sizeof(*query));
 185
 186        query->panel_res = data[1];
 187        query->sensor_id = data[2] & 0x7;
 188        query->capacity_res = data[7];
 189
 190        query->x = data[3] << 9;
 191        query->x |= data[4] << 2;
 192        query->x |= (data[2] >> 5) & 0x3;
 193
 194        query->y = data[5] << 9;
 195        query->y |= data[6] << 2;
 196        query->y |= (data[2] >> 3) & 0x3;
 197
 198        /* Early days' single-finger touch models need the following defaults */
 199        if (!query->x && !query->y) {
 200                query->x = 1024;
 201                query->y = 1024;
 202                if (query->panel_res)
 203                        query->x = query->y = (1 << query->panel_res);
 204                query->panel_res = W8001_TOUCH_RESOLUTION;
 205        }
 206}
 207
 208static void report_pen_events(struct w8001 *w8001, struct w8001_coord *coord)
 209{
 210        struct input_dev *dev = w8001->dev;
 211
 212        /*
 213         * We have 1 bit for proximity (rdy) and 3 bits for tip, side,
 214         * side2/eraser. If rdy && f2 are set, this can be either pen + side2,
 215         * or eraser. Assume:
 216         * - if dev is already in proximity and f2 is toggled → pen + side2
 217         * - if dev comes into proximity with f2 set → eraser
 218         * If f2 disappears after assuming eraser, fake proximity out for
 219         * eraser and in for pen.
 220         */
 221
 222        switch (w8001->type) {
 223        case BTN_TOOL_RUBBER:
 224                if (!coord->f2) {
 225                        input_report_abs(dev, ABS_PRESSURE, 0);
 226                        input_report_key(dev, BTN_TOUCH, 0);
 227                        input_report_key(dev, BTN_STYLUS, 0);
 228                        input_report_key(dev, BTN_STYLUS2, 0);
 229                        input_report_key(dev, BTN_TOOL_RUBBER, 0);
 230                        input_sync(dev);
 231                        w8001->type = BTN_TOOL_PEN;
 232                }
 233                break;
 234
 235        case BTN_TOOL_FINGER:
 236                input_report_key(dev, BTN_TOUCH, 0);
 237                input_report_key(dev, BTN_TOOL_FINGER, 0);
 238                input_sync(dev);
 239                /* fall through */
 240
 241        case KEY_RESERVED:
 242                w8001->type = coord->f2 ? BTN_TOOL_RUBBER : BTN_TOOL_PEN;
 243                break;
 244
 245        default:
 246                input_report_key(dev, BTN_STYLUS2, coord->f2);
 247                break;
 248        }
 249
 250        input_report_abs(dev, ABS_X, coord->x);
 251        input_report_abs(dev, ABS_Y, coord->y);
 252        input_report_abs(dev, ABS_PRESSURE, coord->pen_pressure);
 253        input_report_key(dev, BTN_TOUCH, coord->tsw);
 254        input_report_key(dev, BTN_STYLUS, coord->f1);
 255        input_report_key(dev, w8001->type, coord->rdy);
 256        input_sync(dev);
 257
 258        if (!coord->rdy)
 259                w8001->type = KEY_RESERVED;
 260}
 261
 262static void report_single_touch(struct w8001 *w8001, struct w8001_coord *coord)
 263{
 264        struct input_dev *dev = w8001->dev;
 265        unsigned int x = coord->x;
 266        unsigned int y = coord->y;
 267
 268        /* scale to pen maximum */
 269        scale_touch_coordinates(w8001, &x, &y);
 270
 271        input_report_abs(dev, ABS_X, x);
 272        input_report_abs(dev, ABS_Y, y);
 273        input_report_key(dev, BTN_TOUCH, coord->tsw);
 274        input_report_key(dev, BTN_TOOL_FINGER, coord->tsw);
 275
 276        input_sync(dev);
 277
 278        w8001->type = coord->tsw ? BTN_TOOL_FINGER : KEY_RESERVED;
 279}
 280
 281static irqreturn_t w8001_interrupt(struct serio *serio,
 282                                   unsigned char data, unsigned int flags)
 283{
 284        struct w8001 *w8001 = serio_get_drvdata(serio);
 285        struct w8001_coord coord;
 286        unsigned char tmp;
 287
 288        w8001->data[w8001->idx] = data;
 289        switch (w8001->idx++) {
 290        case 0:
 291                if ((data & W8001_LEAD_MASK) != W8001_LEAD_BYTE) {
 292                        pr_debug("w8001: unsynchronized data: 0x%02x\n", data);
 293                        w8001->idx = 0;
 294                }
 295                break;
 296
 297        case W8001_PKTLEN_TOUCH93 - 1:
 298        case W8001_PKTLEN_TOUCH9A - 1:
 299                tmp = w8001->data[0] & W8001_TOUCH_BYTE;
 300                if (tmp != W8001_TOUCH_BYTE)
 301                        break;
 302
 303                if (w8001->pktlen == w8001->idx) {
 304                        w8001->idx = 0;
 305                        if (w8001->type != BTN_TOOL_PEN &&
 306                            w8001->type != BTN_TOOL_RUBBER) {
 307                                parse_single_touch(w8001->data, &coord);
 308                                report_single_touch(w8001, &coord);
 309                        }
 310                }
 311                break;
 312
 313        /* Pen coordinates packet */
 314        case W8001_PKTLEN_TPCPEN - 1:
 315                tmp = w8001->data[0] & W8001_TAB_MASK;
 316                if (unlikely(tmp == W8001_TAB_BYTE))
 317                        break;
 318
 319                tmp = w8001->data[0] & W8001_TOUCH_BYTE;
 320                if (tmp == W8001_TOUCH_BYTE)
 321                        break;
 322
 323                w8001->idx = 0;
 324                parse_pen_data(w8001->data, &coord);
 325                report_pen_events(w8001, &coord);
 326                break;
 327
 328        /* control packet */
 329        case W8001_PKTLEN_TPCCTL - 1:
 330                tmp = w8001->data[0] & W8001_TOUCH_MASK;
 331                if (tmp == W8001_TOUCH_BYTE)
 332                        break;
 333
 334                w8001->idx = 0;
 335                memcpy(w8001->response, w8001->data, W8001_MAX_LENGTH);
 336                w8001->response_type = W8001_QUERY_PACKET;
 337                complete(&w8001->cmd_done);
 338                break;
 339
 340        /* 2 finger touch packet */
 341        case W8001_PKTLEN_TOUCH2FG - 1:
 342                w8001->idx = 0;
 343                parse_multi_touch(w8001);
 344                break;
 345        }
 346
 347        return IRQ_HANDLED;
 348}
 349
 350static int w8001_command(struct w8001 *w8001, unsigned char command,
 351                         bool wait_response)
 352{
 353        int rc;
 354
 355        w8001->response_type = 0;
 356        init_completion(&w8001->cmd_done);
 357
 358        rc = serio_write(w8001->serio, command);
 359        if (rc == 0 && wait_response) {
 360
 361                wait_for_completion_timeout(&w8001->cmd_done, HZ);
 362                if (w8001->response_type != W8001_QUERY_PACKET)
 363                        rc = -EIO;
 364        }
 365
 366        return rc;
 367}
 368
 369static int w8001_open(struct input_dev *dev)
 370{
 371        struct w8001 *w8001 = input_get_drvdata(dev);
 372
 373        return w8001_command(w8001, W8001_CMD_START, false);
 374}
 375
 376static void w8001_close(struct input_dev *dev)
 377{
 378        struct w8001 *w8001 = input_get_drvdata(dev);
 379
 380        w8001_command(w8001, W8001_CMD_STOP, false);
 381}
 382
 383static int w8001_setup(struct w8001 *w8001)
 384{
 385        struct input_dev *dev = w8001->dev;
 386        struct w8001_coord coord;
 387        struct w8001_touch_query touch;
 388        int error;
 389
 390        error = w8001_command(w8001, W8001_CMD_STOP, false);
 391        if (error)
 392                return error;
 393
 394        msleep(250);    /* wait 250ms before querying the device */
 395
 396        dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 397        strlcat(w8001->name, "Wacom Serial", sizeof(w8001->name));
 398
 399        __set_bit(INPUT_PROP_DIRECT, dev->propbit);
 400
 401        /* penabled? */
 402        error = w8001_command(w8001, W8001_CMD_QUERY, true);
 403        if (!error) {
 404                __set_bit(BTN_TOUCH, dev->keybit);
 405                __set_bit(BTN_TOOL_PEN, dev->keybit);
 406                __set_bit(BTN_TOOL_RUBBER, dev->keybit);
 407                __set_bit(BTN_STYLUS, dev->keybit);
 408                __set_bit(BTN_STYLUS2, dev->keybit);
 409
 410                parse_pen_data(w8001->response, &coord);
 411                w8001->max_pen_x = coord.x;
 412                w8001->max_pen_y = coord.y;
 413
 414                input_set_abs_params(dev, ABS_X, 0, coord.x, 0, 0);
 415                input_set_abs_params(dev, ABS_Y, 0, coord.y, 0, 0);
 416                input_abs_set_res(dev, ABS_X, W8001_PEN_RESOLUTION);
 417                input_abs_set_res(dev, ABS_Y, W8001_PEN_RESOLUTION);
 418                input_set_abs_params(dev, ABS_PRESSURE, 0, coord.pen_pressure, 0, 0);
 419                if (coord.tilt_x && coord.tilt_y) {
 420                        input_set_abs_params(dev, ABS_TILT_X, 0, coord.tilt_x, 0, 0);
 421                        input_set_abs_params(dev, ABS_TILT_Y, 0, coord.tilt_y, 0, 0);
 422                }
 423                w8001->id = 0x90;
 424                strlcat(w8001->name, " Penabled", sizeof(w8001->name));
 425        }
 426
 427        /* Touch enabled? */
 428        error = w8001_command(w8001, W8001_CMD_TOUCHQUERY, true);
 429
 430        /*
 431         * Some non-touch devices may reply to the touch query. But their
 432         * second byte is empty, which indicates touch is not supported.
 433         */
 434        if (!error && w8001->response[1]) {
 435                __set_bit(BTN_TOUCH, dev->keybit);
 436                __set_bit(BTN_TOOL_FINGER, dev->keybit);
 437
 438                parse_touchquery(w8001->response, &touch);
 439                w8001->max_touch_x = touch.x;
 440                w8001->max_touch_y = touch.y;
 441
 442                if (w8001->max_pen_x && w8001->max_pen_y) {
 443                        /* if pen is supported scale to pen maximum */
 444                        touch.x = w8001->max_pen_x;
 445                        touch.y = w8001->max_pen_y;
 446                        touch.panel_res = W8001_PEN_RESOLUTION;
 447                }
 448
 449                input_set_abs_params(dev, ABS_X, 0, touch.x, 0, 0);
 450                input_set_abs_params(dev, ABS_Y, 0, touch.y, 0, 0);
 451                input_abs_set_res(dev, ABS_X, touch.panel_res);
 452                input_abs_set_res(dev, ABS_Y, touch.panel_res);
 453
 454                switch (touch.sensor_id) {
 455                case 0:
 456                case 2:
 457                        w8001->pktlen = W8001_PKTLEN_TOUCH93;
 458                        w8001->id = 0x93;
 459                        strlcat(w8001->name, " 1FG", sizeof(w8001->name));
 460                        break;
 461
 462                case 1:
 463                case 3:
 464                case 4:
 465                        w8001->pktlen = W8001_PKTLEN_TOUCH9A;
 466                        strlcat(w8001->name, " 1FG", sizeof(w8001->name));
 467                        w8001->id = 0x9a;
 468                        break;
 469
 470                case 5:
 471                        w8001->pktlen = W8001_PKTLEN_TOUCH2FG;
 472
 473                        input_mt_init_slots(dev, 2, 0);
 474                        input_set_abs_params(dev, ABS_MT_POSITION_X,
 475                                                0, touch.x, 0, 0);
 476                        input_set_abs_params(dev, ABS_MT_POSITION_Y,
 477                                                0, touch.y, 0, 0);
 478                        input_set_abs_params(dev, ABS_MT_TOOL_TYPE,
 479                                                0, MT_TOOL_MAX, 0, 0);
 480
 481                        strlcat(w8001->name, " 2FG", sizeof(w8001->name));
 482                        if (w8001->max_pen_x && w8001->max_pen_y)
 483                                w8001->id = 0xE3;
 484                        else
 485                                w8001->id = 0xE2;
 486                        break;
 487                }
 488        }
 489
 490        strlcat(w8001->name, " Touchscreen", sizeof(w8001->name));
 491
 492        return 0;
 493}
 494
 495/*
 496 * w8001_disconnect() is the opposite of w8001_connect()
 497 */
 498
 499static void w8001_disconnect(struct serio *serio)
 500{
 501        struct w8001 *w8001 = serio_get_drvdata(serio);
 502
 503        serio_close(serio);
 504
 505        input_unregister_device(w8001->dev);
 506        kfree(w8001);
 507
 508        serio_set_drvdata(serio, NULL);
 509}
 510
 511/*
 512 * w8001_connect() is the routine that is called when someone adds a
 513 * new serio device that supports the w8001 protocol and registers it as
 514 * an input device.
 515 */
 516
 517static int w8001_connect(struct serio *serio, struct serio_driver *drv)
 518{
 519        struct w8001 *w8001;
 520        struct input_dev *input_dev;
 521        int err;
 522
 523        w8001 = kzalloc(sizeof(struct w8001), GFP_KERNEL);
 524        input_dev = input_allocate_device();
 525        if (!w8001 || !input_dev) {
 526                err = -ENOMEM;
 527                goto fail1;
 528        }
 529
 530        w8001->serio = serio;
 531        w8001->dev = input_dev;
 532        init_completion(&w8001->cmd_done);
 533        snprintf(w8001->phys, sizeof(w8001->phys), "%s/input0", serio->phys);
 534
 535        serio_set_drvdata(serio, w8001);
 536        err = serio_open(serio, drv);
 537        if (err)
 538                goto fail2;
 539
 540        err = w8001_setup(w8001);
 541        if (err)
 542                goto fail3;
 543
 544        input_dev->name = w8001->name;
 545        input_dev->phys = w8001->phys;
 546        input_dev->id.product = w8001->id;
 547        input_dev->id.bustype = BUS_RS232;
 548        input_dev->id.vendor = 0x056a;
 549        input_dev->id.version = 0x0100;
 550        input_dev->dev.parent = &serio->dev;
 551
 552        input_dev->open = w8001_open;
 553        input_dev->close = w8001_close;
 554
 555        input_set_drvdata(input_dev, w8001);
 556
 557        err = input_register_device(w8001->dev);
 558        if (err)
 559                goto fail3;
 560
 561        return 0;
 562
 563fail3:
 564        serio_close(serio);
 565fail2:
 566        serio_set_drvdata(serio, NULL);
 567fail1:
 568        input_free_device(input_dev);
 569        kfree(w8001);
 570        return err;
 571}
 572
 573static struct serio_device_id w8001_serio_ids[] = {
 574        {
 575                .type   = SERIO_RS232,
 576                .proto  = SERIO_W8001,
 577                .id     = SERIO_ANY,
 578                .extra  = SERIO_ANY,
 579        },
 580        { 0 }
 581};
 582
 583MODULE_DEVICE_TABLE(serio, w8001_serio_ids);
 584
 585static struct serio_driver w8001_drv = {
 586        .driver         = {
 587                .name   = "w8001",
 588        },
 589        .description    = DRIVER_DESC,
 590        .id_table       = w8001_serio_ids,
 591        .interrupt      = w8001_interrupt,
 592        .connect        = w8001_connect,
 593        .disconnect     = w8001_disconnect,
 594};
 595
 596module_serio_driver(w8001_drv);
 597