qemu

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/*
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 * QEMU Wacom Penpartner serial tablet emulation
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 *
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 * some protocol details:
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 *   http://linuxwacom.sourceforge.net/wiki/index.php/Serial_Protocol_IV
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 *
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 * Copyright (c) 2016 Anatoli Huseu1
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 * Copyright (c) 2016,17 Gerd Hoffmann
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 *
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 * Permission is hereby granted, free of charge, to any person obtaining a copy
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 * of this software and associated documentation files (the "Software"), to
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 * deal in the Software without restriction, including without limitation
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 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
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 * and/or sell copies of the Software, and to permit persons to whom the
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 * Software is furnished to do so, subject to the following conditions:
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 *
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 * The above copyright notice and this permission notice shall be included in
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 * all copies or substantial portions of the Software.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM
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 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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 * THE SOFTWARE.
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 */
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#include "qemu/osdep.h"
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#include "qemu/module.h"
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#include "chardev/char-serial.h"
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#include "ui/console.h"
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#include "ui/input.h"
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#include "trace.h"
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#include "qom/object.h"
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#define WC_OUTPUT_BUF_MAX_LEN 512
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#define WC_COMMAND_MAX_LEN 60
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#define WC_L7(n) ((n) & 127)
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#define WC_M7(n) (((n) >> 7) & 127)
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#define WC_H2(n) ((n) >> 14)
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#define WC_L4(n) ((n) & 15)
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#define WC_H4(n) (((n) >> 4) & 15)
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/* Model string and config string */
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#define WC_MODEL_STRING_LENGTH 18
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uint8_t WC_MODEL_STRING[WC_MODEL_STRING_LENGTH + 1] = "~#CT-0045R,V1.3-5,";
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#define WC_CONFIG_STRING_LENGTH 8
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uint8_t WC_CONFIG_STRING[WC_CONFIG_STRING_LENGTH + 1] = "96,N,8,0";
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#define WC_FULL_CONFIG_STRING_LENGTH 61
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uint8_t WC_FULL_CONFIG_STRING[WC_FULL_CONFIG_STRING_LENGTH + 1] = {
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    0x5c, 0x39, 0x36, 0x2c, 0x4e, 0x2c, 0x38, 0x2c,
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    0x31, 0x28, 0x01, 0x24, 0x57, 0x41, 0x43, 0x30,
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    0x30, 0x34, 0x35, 0x5c, 0x5c, 0x50, 0x45, 0x4e, 0x5c,
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    0x57, 0x41, 0x43, 0x30, 0x30, 0x30, 0x30, 0x5c,
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    0x54, 0x61, 0x62, 0x6c, 0x65, 0x74, 0x0d, 0x0a,
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    0x43, 0x54, 0x2d, 0x30, 0x30, 0x34, 0x35, 0x52,
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    0x2c, 0x56, 0x31, 0x2e, 0x33, 0x2d, 0x35, 0x0d,
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    0x0a, 0x45, 0x37, 0x29
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};
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/* This structure is used to save private info for Wacom Tablet. */
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struct TabletChardev {
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    Chardev parent;
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    QemuInputHandlerState *hs;
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    /* Query string from serial */
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    uint8_t query[100];
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    int query_index;
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    /* Command to be sent to serial port */
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    uint8_t outbuf[WC_OUTPUT_BUF_MAX_LEN];
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    int outlen;
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    int line_speed;
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    bool send_events;
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    int axis[INPUT_AXIS__MAX];
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    bool btns[INPUT_BUTTON__MAX];
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};
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typedef struct TabletChardev TabletChardev;
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#define TYPE_CHARDEV_WCTABLET "chardev-wctablet"
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DECLARE_INSTANCE_CHECKER(TabletChardev, WCTABLET_CHARDEV,
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                         TYPE_CHARDEV_WCTABLET)
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static void wctablet_chr_accept_input(Chardev *chr);
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static void wctablet_shift_input(TabletChardev *tablet, int count)
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{
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    tablet->query_index -= count;
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    memmove(tablet->query, tablet->query + count, tablet->query_index);
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    tablet->query[tablet->query_index] = 0;
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}
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static void wctablet_queue_output(TabletChardev *tablet, uint8_t *buf, int count)
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{
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    if (tablet->outlen + count > sizeof(tablet->outbuf)) {
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        return;
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    }
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    memcpy(tablet->outbuf + tablet->outlen, buf, count);
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    tablet->outlen += count;
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    wctablet_chr_accept_input(CHARDEV(tablet));
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}
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static void wctablet_reset(TabletChardev *tablet)
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{
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    /* clear buffers */
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    tablet->query_index = 0;
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    tablet->outlen = 0;
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    /* reset state */
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    tablet->send_events = false;
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}
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static void wctablet_queue_event(TabletChardev *tablet)
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{
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    uint8_t codes[8] = { 0xe0, 0, 0, 0, 0, 0, 0 };
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    if (tablet->line_speed != 9600) {
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        return;
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    }
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    int newX = tablet->axis[INPUT_AXIS_X] * 0.1537;
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    int nexY = tablet->axis[INPUT_AXIS_Y] * 0.1152;
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    codes[0] = codes[0] | WC_H2(newX);
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    codes[1] = codes[1] | WC_M7(newX);
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    codes[2] = codes[2] | WC_L7(newX);
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    codes[3] = codes[3] | WC_H2(nexY);
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    codes[4] = codes[4] | WC_M7(nexY);
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    codes[5] = codes[5] | WC_L7(nexY);
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    if (tablet->btns[INPUT_BUTTON_LEFT]) {
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        codes[0] = 0xa0;
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    }
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    wctablet_queue_output(tablet, codes, 7);
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}
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static void wctablet_input_event(DeviceState *dev, QemuConsole *src,
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                                InputEvent *evt)
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{
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    TabletChardev *tablet = (TabletChardev *)dev;
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    InputMoveEvent *move;
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    InputBtnEvent *btn;
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    switch (evt->type) {
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    case INPUT_EVENT_KIND_ABS:
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        move = evt->u.abs.data;
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        tablet->axis[move->axis] = move->value;
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        break;
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    case INPUT_EVENT_KIND_BTN:
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        btn = evt->u.btn.data;
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        tablet->btns[btn->button] = btn->down;
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        break;
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    default:
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        /* keep gcc happy */
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        break;
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    }
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}
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static void wctablet_input_sync(DeviceState *dev)
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{
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    TabletChardev *tablet = (TabletChardev *)dev;
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    if (tablet->send_events) {
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        wctablet_queue_event(tablet);
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    }
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}
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static const QemuInputHandler wctablet_handler = {
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    .name  = "QEMU Wacom Pen Tablet",
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    .mask  = INPUT_EVENT_MASK_BTN | INPUT_EVENT_MASK_ABS,
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    .event = wctablet_input_event,
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    .sync  = wctablet_input_sync,
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};
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static void wctablet_chr_accept_input(Chardev *chr)
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{
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    TabletChardev *tablet = WCTABLET_CHARDEV(chr);
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    int len, canWrite;
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    canWrite = qemu_chr_be_can_write(chr);
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    len = canWrite;
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    if (len > tablet->outlen) {
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        len = tablet->outlen;
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    }
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    if (len) {
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        qemu_chr_be_write(chr, tablet->outbuf, len);
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        tablet->outlen -= len;
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        if (tablet->outlen) {
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            memmove(tablet->outbuf, tablet->outbuf + len, tablet->outlen);
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        }
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    }
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}
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static int wctablet_chr_write(struct Chardev *chr,
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                              const uint8_t *buf, int len)
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{
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    TabletChardev *tablet = WCTABLET_CHARDEV(chr);
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    unsigned int i, clen;
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    char *pos;
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    if (tablet->line_speed != 9600) {
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        return len;
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    }
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    for (i = 0; i < len && tablet->query_index < sizeof(tablet->query) - 1; i++) {
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        tablet->query[tablet->query_index++] = buf[i];
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    }
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    tablet->query[tablet->query_index] = 0;
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    while (tablet->query_index > 0 && (tablet->query[0] == '@'  ||
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                                       tablet->query[0] == '\r' ||
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                                       tablet->query[0] == '\n')) {
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        wctablet_shift_input(tablet, 1);
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    }
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    if (!tablet->query_index) {
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        return len;
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    }
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    if (strncmp((char *)tablet->query, "~#", 2) == 0) {
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        /* init / detect sequence */
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        trace_wct_init();
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        wctablet_shift_input(tablet, 2);
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        wctablet_queue_output(tablet, WC_MODEL_STRING,
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                              WC_MODEL_STRING_LENGTH);
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        return len;
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    }
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    /* detect line */
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    pos = strchr((char *)tablet->query, '\r');
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    if (!pos) {
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        pos = strchr((char *)tablet->query, '\n');
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    }
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    if (!pos) {
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        return len;
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    }
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    clen = pos - (char *)tablet->query;
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    /* process commands */
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    if (strncmp((char *)tablet->query, "RE", 2) == 0 &&
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        clen == 2) {
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        trace_wct_cmd_re();
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        wctablet_shift_input(tablet, 3);
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        wctablet_queue_output(tablet, WC_CONFIG_STRING,
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                              WC_CONFIG_STRING_LENGTH);
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    } else if (strncmp((char *)tablet->query, "ST", 2) == 0 &&
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               clen == 2) {
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        trace_wct_cmd_st();
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        wctablet_shift_input(tablet, 3);
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        tablet->send_events = true;
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        wctablet_queue_event(tablet);
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    } else if (strncmp((char *)tablet->query, "SP", 2) == 0 &&
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               clen == 2) {
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        trace_wct_cmd_sp();
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        wctablet_shift_input(tablet, 3);
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        tablet->send_events = false;
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    } else if (strncmp((char *)tablet->query, "TS", 2) == 0 &&
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               clen == 3) {
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        unsigned int input = tablet->query[2];
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        uint8_t codes[7] = {
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            0xa3,
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            ((input & 0x80) == 0) ? 0x7e : 0x7f,
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            (((WC_H4(input) & 0x7) ^ 0x5) << 4) | (WC_L4(input) ^ 0x7),
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            0x03,
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            0x7f,
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            0x7f,
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            0x00,
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        };
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        trace_wct_cmd_ts(input);
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        wctablet_shift_input(tablet, 4);
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        wctablet_queue_output(tablet, codes, 7);
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    } else {
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        tablet->query[clen] = 0; /* terminate line for printing */
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        trace_wct_cmd_other((char *)tablet->query);
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        wctablet_shift_input(tablet, clen + 1);
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    }
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    return len;
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}
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static int wctablet_chr_ioctl(Chardev *chr, int cmd, void *arg)
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{
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    TabletChardev *tablet = WCTABLET_CHARDEV(chr);
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    QEMUSerialSetParams *ssp;
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    switch (cmd) {
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    case CHR_IOCTL_SERIAL_SET_PARAMS:
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        ssp = arg;
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        if (tablet->line_speed != ssp->speed) {
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            trace_wct_speed(ssp->speed);
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            wctablet_reset(tablet);
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            tablet->line_speed = ssp->speed;
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        }
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        break;
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    default:
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        return -ENOTSUP;
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    }
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    return 0;
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}
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static void wctablet_chr_finalize(Object *obj)
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{
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    TabletChardev *tablet = WCTABLET_CHARDEV(obj);
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    if (tablet->hs) {
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        qemu_input_handler_unregister(tablet->hs);
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    }
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}
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static void wctablet_chr_open(Chardev *chr,
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                              ChardevBackend *backend,
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                              bool *be_opened,
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                              Error **errp)
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{
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    TabletChardev *tablet = WCTABLET_CHARDEV(chr);
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    *be_opened = true;
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    /* init state machine */
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    memcpy(tablet->outbuf, WC_FULL_CONFIG_STRING, WC_FULL_CONFIG_STRING_LENGTH);
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    tablet->outlen = WC_FULL_CONFIG_STRING_LENGTH;
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    tablet->query_index = 0;
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    tablet->hs = qemu_input_handler_register((DeviceState *)tablet,
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                                             &wctablet_handler);
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}
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static void wctablet_chr_class_init(ObjectClass *oc, void *data)
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{
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    ChardevClass *cc = CHARDEV_CLASS(oc);
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    cc->open = wctablet_chr_open;
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    cc->chr_write = wctablet_chr_write;
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    cc->chr_ioctl = wctablet_chr_ioctl;
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    cc->chr_accept_input = wctablet_chr_accept_input;
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}
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static const TypeInfo wctablet_type_info = {
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    .name = TYPE_CHARDEV_WCTABLET,
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    .parent = TYPE_CHARDEV,
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    .instance_size = sizeof(TabletChardev),
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    .instance_finalize = wctablet_chr_finalize,
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    .class_init = wctablet_chr_class_init,
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};
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static void register_types(void)
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{
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     type_register_static(&wctablet_type_info);
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}
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type_init(register_types);
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