chardev/wctablet.c

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