qemu/chardev/wctablet.c
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   1/*
   2 * QEMU Wacom Penpartner serial tablet emulation
   3 *
   4 * some protocol details:
   5 *   http://linuxwacom.sourceforge.net/wiki/index.php/Serial_Protocol_IV
   6 *
   7 * Copyright (c) 2016 Anatoli Huseu1
   8 * Copyright (c) 2016,17 Gerd Hoffmann
   9 *
  10 * Permission is hereby granted, free of charge, to any person obtaining a copy
  11 * of this software and associated documentation files (the "Software"), to
  12 * deal in the Software without restriction, including without limitation
  13 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  14 * and/or sell copies of the Software, and to permit persons to whom the
  15 * Software is furnished to do so, subject to the following conditions:
  16 *
  17 * The above copyright notice and this permission notice shall be included in
  18 * all copies or substantial portions of the Software.
  19 *
  20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM
  25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  26 * THE SOFTWARE.
  27 */
  28#include <stdlib.h>
  29#include <string.h>
  30#include <sys/time.h>
  31#include <time.h>
  32
  33#include "qemu/osdep.h"
  34#include "qemu-common.h"
  35#include "chardev/char-serial.h"
  36#include "ui/console.h"
  37#include "ui/input.h"
  38#include "trace.h"
  39
  40
  41#define WC_OUTPUT_BUF_MAX_LEN 512
  42#define WC_COMMAND_MAX_LEN 60
  43
  44#define WC_L7(n) ((n) & 127)
  45#define WC_M7(n) (((n) >> 7) & 127)
  46#define WC_H2(n) ((n) >> 14)
  47
  48#define WC_L4(n) ((n) & 15)
  49#define WC_H4(n) (((n) >> 4) & 15)
  50
  51/* Model string and config string */
  52#define WC_MODEL_STRING_LENGTH 18
  53uint8_t WC_MODEL_STRING[WC_MODEL_STRING_LENGTH + 1] = "~#CT-0045R,V1.3-5,";
  54
  55#define WC_CONFIG_STRING_LENGTH 8
  56uint8_t WC_CONFIG_STRING[WC_CONFIG_STRING_LENGTH + 1] = "96,N,8,0";
  57
  58#define WC_FULL_CONFIG_STRING_LENGTH 61
  59uint8_t WC_FULL_CONFIG_STRING[WC_FULL_CONFIG_STRING_LENGTH + 1] = {
  60    0x5c, 0x39, 0x36, 0x2c, 0x4e, 0x2c, 0x38, 0x2c,
  61    0x31, 0x28, 0x01, 0x24, 0x57, 0x41, 0x43, 0x30,
  62    0x30, 0x34, 0x35, 0x5c, 0x5c, 0x50, 0x45, 0x4e, 0x5c,
  63    0x57, 0x41, 0x43, 0x30, 0x30, 0x30, 0x30, 0x5c,
  64    0x54, 0x61, 0x62, 0x6c, 0x65, 0x74, 0x0d, 0x0a,
  65    0x43, 0x54, 0x2d, 0x30, 0x30, 0x34, 0x35, 0x52,
  66    0x2c, 0x56, 0x31, 0x2e, 0x33, 0x2d, 0x35, 0x0d,
  67    0x0a, 0x45, 0x37, 0x29
  68};
  69
  70/* This structure is used to save private info for Wacom Tablet. */
  71typedef struct {
  72    Chardev parent;
  73    QemuInputHandlerState *hs;
  74
  75    /* Query string from serial */
  76    uint8_t query[100];
  77    int query_index;
  78
  79    /* Command to be sent to serial port */
  80    uint8_t outbuf[WC_OUTPUT_BUF_MAX_LEN];
  81    int outlen;
  82
  83    int line_speed;
  84    bool send_events;
  85    int axis[INPUT_AXIS__MAX];
  86    bool btns[INPUT_BUTTON__MAX];
  87
  88} TabletChardev;
  89
  90#define TYPE_CHARDEV_WCTABLET "chardev-wctablet"
  91#define WCTABLET_CHARDEV(obj)                                      \
  92    OBJECT_CHECK(TabletChardev, (obj), TYPE_CHARDEV_WCTABLET)
  93
  94
  95static void wctablet_chr_accept_input(Chardev *chr);
  96
  97static void wctablet_shift_input(TabletChardev *tablet, int count)
  98{
  99    tablet->query_index -= count;
 100    memmove(tablet->query, tablet->query + count, tablet->query_index);
 101    tablet->query[tablet->query_index] = 0;
 102}
 103
 104static void wctablet_queue_output(TabletChardev *tablet, uint8_t *buf, int count)
 105{
 106    if (tablet->outlen + count > sizeof(tablet->outbuf)) {
 107        return;
 108    }
 109
 110    memcpy(tablet->outbuf + tablet->outlen, buf, count);
 111    tablet->outlen += count;
 112    wctablet_chr_accept_input(CHARDEV(tablet));
 113}
 114
 115static void wctablet_reset(TabletChardev *tablet)
 116{
 117    /* clear buffers */
 118    tablet->query_index = 0;
 119    tablet->outlen = 0;
 120    /* reset state */
 121    tablet->send_events = false;
 122}
 123
 124static void wctablet_queue_event(TabletChardev *tablet)
 125{
 126    uint8_t codes[8] = { 0xe0, 0, 0, 0, 0, 0, 0 };
 127
 128    if (tablet->line_speed != 9600) {
 129        return;
 130    }
 131
 132    int newX = tablet->axis[INPUT_AXIS_X] * 0.1537;
 133    int nexY = tablet->axis[INPUT_AXIS_Y] * 0.1152;
 134
 135    codes[0] = codes[0] | WC_H2(newX);
 136    codes[1] = codes[1] | WC_M7(newX);
 137    codes[2] = codes[2] | WC_L7(newX);
 138
 139    codes[3] = codes[3] | WC_H2(nexY);
 140    codes[4] = codes[4] | WC_M7(nexY);
 141    codes[5] = codes[5] | WC_L7(nexY);
 142
 143    if (tablet->btns[INPUT_BUTTON_LEFT]) {
 144        codes[0] = 0xa0;
 145    }
 146
 147    wctablet_queue_output(tablet, codes, 7);
 148}
 149
 150static void wctablet_input_event(DeviceState *dev, QemuConsole *src,
 151                                InputEvent *evt)
 152{
 153    TabletChardev *tablet = (TabletChardev *)dev;
 154    InputMoveEvent *move;
 155    InputBtnEvent *btn;
 156
 157    switch (evt->type) {
 158    case INPUT_EVENT_KIND_ABS:
 159        move = evt->u.abs.data;
 160        tablet->axis[move->axis] = move->value;
 161        break;
 162
 163    case INPUT_EVENT_KIND_BTN:
 164        btn = evt->u.btn.data;
 165        tablet->btns[btn->button] = btn->down;
 166        break;
 167
 168    default:
 169        /* keep gcc happy */
 170        break;
 171    }
 172}
 173
 174static void wctablet_input_sync(DeviceState *dev)
 175{
 176    TabletChardev *tablet = (TabletChardev *)dev;
 177
 178    if (tablet->send_events) {
 179        wctablet_queue_event(tablet);
 180    }
 181}
 182
 183static QemuInputHandler wctablet_handler = {
 184    .name  = "QEMU Wacome Pen Tablet",
 185    .mask  = INPUT_EVENT_MASK_BTN | INPUT_EVENT_MASK_ABS,
 186    .event = wctablet_input_event,
 187    .sync  = wctablet_input_sync,
 188};
 189
 190static void wctablet_chr_accept_input(Chardev *chr)
 191{
 192    TabletChardev *tablet = WCTABLET_CHARDEV(chr);
 193    int len, canWrite;
 194
 195    canWrite = qemu_chr_be_can_write(chr);
 196    len = canWrite;
 197    if (len > tablet->outlen) {
 198        len = tablet->outlen;
 199    }
 200
 201    if (len) {
 202        qemu_chr_be_write(chr, tablet->outbuf, len);
 203        tablet->outlen -= len;
 204        if (tablet->outlen) {
 205            memmove(tablet->outbuf, tablet->outbuf + len, tablet->outlen);
 206        }
 207    }
 208}
 209
 210static int wctablet_chr_write(struct Chardev *chr,
 211                              const uint8_t *buf, int len)
 212{
 213    TabletChardev *tablet = WCTABLET_CHARDEV(chr);
 214    unsigned int i, clen;
 215    char *pos;
 216
 217    if (tablet->line_speed != 9600) {
 218        return len;
 219    }
 220    for (i = 0; i < len && tablet->query_index < sizeof(tablet->query) - 1; i++) {
 221        tablet->query[tablet->query_index++] = buf[i];
 222    }
 223    tablet->query[tablet->query_index] = 0;
 224
 225    while (tablet->query_index > 0 && (tablet->query[0] == '@'  ||
 226                                       tablet->query[0] == '\r' ||
 227                                       tablet->query[0] == '\n')) {
 228        wctablet_shift_input(tablet, 1);
 229    }
 230    if (!tablet->query_index) {
 231        return len;
 232    }
 233
 234    if (strncmp((char *)tablet->query, "~#", 2) == 0) {
 235        /* init / detect sequence */
 236        trace_wct_init();
 237        wctablet_shift_input(tablet, 2);
 238        wctablet_queue_output(tablet, WC_MODEL_STRING,
 239                              WC_MODEL_STRING_LENGTH);
 240        return len;
 241    }
 242
 243    /* detect line */
 244    pos = strchr((char *)tablet->query, '\r');
 245    if (!pos) {
 246        pos = strchr((char *)tablet->query, '\n');
 247    }
 248    if (!pos) {
 249        return len;
 250    }
 251    clen = pos - (char *)tablet->query;
 252
 253    /* process commands */
 254    if (strncmp((char *)tablet->query, "RE", 2) == 0 &&
 255        clen == 2) {
 256        trace_wct_cmd_re();
 257        wctablet_shift_input(tablet, 3);
 258        wctablet_queue_output(tablet, WC_CONFIG_STRING,
 259                              WC_CONFIG_STRING_LENGTH);
 260
 261    } else if (strncmp((char *)tablet->query, "ST", 2) == 0 &&
 262               clen == 2) {
 263        trace_wct_cmd_st();
 264        wctablet_shift_input(tablet, 3);
 265        tablet->send_events = true;
 266        wctablet_queue_event(tablet);
 267
 268    } else if (strncmp((char *)tablet->query, "SP", 2) == 0 &&
 269               clen == 2) {
 270        trace_wct_cmd_sp();
 271        wctablet_shift_input(tablet, 3);
 272        tablet->send_events = false;
 273
 274    } else if (strncmp((char *)tablet->query, "TS", 2) == 0 &&
 275               clen == 3) {
 276        unsigned int input = tablet->query[2];
 277        uint8_t codes[7] = {
 278            0xa3,
 279            ((input & 0x80) == 0) ? 0x7e : 0x7f,
 280            (((WC_H4(input) & 0x7) ^ 0x5) << 4) | (WC_L4(input) ^ 0x7),
 281            0x03,
 282            0x7f,
 283            0x7f,
 284            0x00,
 285        };
 286        trace_wct_cmd_ts(input);
 287        wctablet_shift_input(tablet, 4);
 288        wctablet_queue_output(tablet, codes, 7);
 289
 290    } else {
 291        tablet->query[clen] = 0; /* terminate line for printing */
 292        trace_wct_cmd_other((char *)tablet->query);
 293        wctablet_shift_input(tablet, clen + 1);
 294
 295    }
 296
 297    return len;
 298}
 299
 300static int wctablet_chr_ioctl(Chardev *chr, int cmd, void *arg)
 301{
 302    TabletChardev *tablet = WCTABLET_CHARDEV(chr);
 303    QEMUSerialSetParams *ssp;
 304
 305    switch (cmd) {
 306    case CHR_IOCTL_SERIAL_SET_PARAMS:
 307        ssp = arg;
 308        if (tablet->line_speed != ssp->speed) {
 309            trace_wct_speed(ssp->speed);
 310            wctablet_reset(tablet);
 311            tablet->line_speed = ssp->speed;
 312        }
 313        break;
 314    default:
 315        return -ENOTSUP;
 316    }
 317    return 0;
 318}
 319
 320static void wctablet_chr_finalize(Object *obj)
 321{
 322    TabletChardev *tablet = WCTABLET_CHARDEV(obj);
 323
 324    qemu_input_handler_unregister(tablet->hs);
 325    g_free(tablet);
 326}
 327
 328static void wctablet_chr_open(Chardev *chr,
 329                              ChardevBackend *backend,
 330                              bool *be_opened,
 331                              Error **errp)
 332{
 333    TabletChardev *tablet = WCTABLET_CHARDEV(chr);
 334
 335    *be_opened = true;
 336
 337    /* init state machine */
 338    memcpy(tablet->outbuf, WC_FULL_CONFIG_STRING, WC_FULL_CONFIG_STRING_LENGTH);
 339    tablet->outlen = WC_FULL_CONFIG_STRING_LENGTH;
 340    tablet->query_index = 0;
 341
 342    tablet->hs = qemu_input_handler_register((DeviceState *)tablet,
 343                                             &wctablet_handler);
 344}
 345
 346static void wctablet_chr_class_init(ObjectClass *oc, void *data)
 347{
 348    ChardevClass *cc = CHARDEV_CLASS(oc);
 349
 350    cc->open = wctablet_chr_open;
 351    cc->chr_write = wctablet_chr_write;
 352    cc->chr_ioctl = wctablet_chr_ioctl;
 353    cc->chr_accept_input = wctablet_chr_accept_input;
 354}
 355
 356static const TypeInfo wctablet_type_info = {
 357    .name = TYPE_CHARDEV_WCTABLET,
 358    .parent = TYPE_CHARDEV,
 359    .instance_size = sizeof(TabletChardev),
 360    .instance_finalize = wctablet_chr_finalize,
 361    .class_init = wctablet_chr_class_init,
 362};
 363
 364static void register_types(void)
 365{
 366     type_register_static(&wctablet_type_info);
 367}
 368
 369type_init(register_types);
 370