chardev/wctablet.c - qemu - Git at Google

 /*
  * QEMU Wacom Penpartner serial tablet emulation
  *
  * some protocol details:
  *   http://linuxwacom.sourceforge.net/wiki/index.php/Serial_Protocol_IV
  *
  * Copyright (c) 2016 Anatoli Huseu1
  * Copyright (c) 2016,17 Gerd Hoffmann
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to
  * deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

 #include "qemu/osdep.h"
 #include "qemu/module.h"
 #include "chardev/char-serial.h"
 #include "ui/console.h"
 #include "ui/input.h"
 #include "trace.h"
 #include "qom/object.h"


 #define WC_OUTPUT_BUF_MAX_LEN 512
 #define WC_COMMAND_MAX_LEN 60

 #define WC_L7(n) ((n) & 127)
 #define WC_M7(n) (((n) >> 7) & 127)
 #define WC_H2(n) ((n) >> 14)

 #define WC_L4(n) ((n) & 15)
 #define WC_H4(n) (((n) >> 4) & 15)

 /* Model string and config string */
 #define WC_MODEL_STRING_LENGTH 18
 uint8_t WC_MODEL_STRING[WC_MODEL_STRING_LENGTH + 1] = "~#CT-0045R,V1.3-5,";

 #define WC_CONFIG_STRING_LENGTH 8
 uint8_t WC_CONFIG_STRING[WC_CONFIG_STRING_LENGTH + 1] = "96,N,8,0";

 #define WC_FULL_CONFIG_STRING_LENGTH 61
 uint8_t WC_FULL_CONFIG_STRING[WC_FULL_CONFIG_STRING_LENGTH + 1] = {
     0x5c, 0x39, 0x36, 0x2c, 0x4e, 0x2c, 0x38, 0x2c,
     0x31, 0x28, 0x01, 0x24, 0x57, 0x41, 0x43, 0x30,
     0x30, 0x34, 0x35, 0x5c, 0x5c, 0x50, 0x45, 0x4e, 0x5c,
     0x57, 0x41, 0x43, 0x30, 0x30, 0x30, 0x30, 0x5c,
     0x54, 0x61, 0x62, 0x6c, 0x65, 0x74, 0x0d, 0x0a,
     0x43, 0x54, 0x2d, 0x30, 0x30, 0x34, 0x35, 0x52,
     0x2c, 0x56, 0x31, 0x2e, 0x33, 0x2d, 0x35, 0x0d,
     0x0a, 0x45, 0x37, 0x29
 };

 /* This structure is used to save private info for Wacom Tablet. */
 struct TabletChardev {
     Chardev parent;
     QemuInputHandlerState *hs;

     /* Query string from serial */
     uint8_t query[100];
     int query_index;

     /* Command to be sent to serial port */
     uint8_t outbuf[WC_OUTPUT_BUF_MAX_LEN];
     int outlen;

     int line_speed;
     bool send_events;
     int axis[INPUT_AXIS__MAX];
     bool btns[INPUT_BUTTON__MAX];

 };
 typedef struct TabletChardev TabletChardev;

 #define TYPE_CHARDEV_WCTABLET "chardev-wctablet"
 DECLARE_INSTANCE_CHECKER(TabletChardev, WCTABLET_CHARDEV,
                          TYPE_CHARDEV_WCTABLET)


 static void wctablet_chr_accept_input(Chardev *chr);

 static void wctablet_shift_input(TabletChardev *tablet, int count)
 {
     tablet->query_index -= count;
     memmove(tablet->query, tablet->query + count, tablet->query_index);
     tablet->query[tablet->query_index] = 0;
 }

 static void wctablet_queue_output(TabletChardev *tablet, uint8_t *buf, int count)
 {
     if (tablet->outlen + count > sizeof(tablet->outbuf)) {
         return;
     }

     memcpy(tablet->outbuf + tablet->outlen, buf, count);
     tablet->outlen += count;
     wctablet_chr_accept_input(CHARDEV(tablet));
 }

 static void wctablet_reset(TabletChardev *tablet)
 {
     /* clear buffers */
     tablet->query_index = 0;
     tablet->outlen = 0;
     /* reset state */
     tablet->send_events = false;
 }

 static void wctablet_queue_event(TabletChardev *tablet)
 {
     uint8_t codes[8] = { 0xe0, 0, 0, 0, 0, 0, 0 };

     if (tablet->line_speed != 9600) {
         return;
     }

     int newX = tablet->axis[INPUT_AXIS_X] * 0.1537;
     int nexY = tablet->axis[INPUT_AXIS_Y] * 0.1152;

     codes[0] = codes[0] | WC_H2(newX);
     codes[1] = codes[1] | WC_M7(newX);
     codes[2] = codes[2] | WC_L7(newX);

     codes[3] = codes[3] | WC_H2(nexY);
     codes[4] = codes[4] | WC_M7(nexY);
     codes[5] = codes[5] | WC_L7(nexY);

     if (tablet->btns[INPUT_BUTTON_LEFT]) {
         codes[0] = 0xa0;
     }

     wctablet_queue_output(tablet, codes, 7);
 }

 static void wctablet_input_event(DeviceState *dev, QemuConsole *src,
                                 InputEvent *evt)
 {
     TabletChardev *tablet = (TabletChardev *)dev;
     InputMoveEvent *move;
     InputBtnEvent *btn;

     switch (evt->type) {
     case INPUT_EVENT_KIND_ABS:
         move = evt->u.abs.data;
         tablet->axis[move->axis] = move->value;
         break;

     case INPUT_EVENT_KIND_BTN:
         btn = evt->u.btn.data;
         tablet->btns[btn->button] = btn->down;
         break;

     default:
         /* keep gcc happy */
         break;
     }
 }

 static void wctablet_input_sync(DeviceState *dev)
 {
     TabletChardev *tablet = (TabletChardev *)dev;

     if (tablet->send_events) {
         wctablet_queue_event(tablet);
     }
 }

 static QemuInputHandler wctablet_handler = {
     .name  = "QEMU Wacom Pen Tablet",
     .mask  = INPUT_EVENT_MASK_BTN | INPUT_EVENT_MASK_ABS,
     .event = wctablet_input_event,
     .sync  = wctablet_input_sync,
 };

 static void wctablet_chr_accept_input(Chardev *chr)
 {
     TabletChardev *tablet = WCTABLET_CHARDEV(chr);
     int len, canWrite;

     canWrite = qemu_chr_be_can_write(chr);
     len = canWrite;
     if (len > tablet->outlen) {
         len = tablet->outlen;
     }

     if (len) {
         qemu_chr_be_write(chr, tablet->outbuf, len);
         tablet->outlen -= len;
         if (tablet->outlen) {
             memmove(tablet->outbuf, tablet->outbuf + len, tablet->outlen);
         }
     }
 }

 static int wctablet_chr_write(struct Chardev *chr,
                               const uint8_t *buf, int len)
 {
     TabletChardev *tablet = WCTABLET_CHARDEV(chr);
     unsigned int i, clen;
     char *pos;

     if (tablet->line_speed != 9600) {
         return len;
     }
     for (i = 0; i < len && tablet->query_index < sizeof(tablet->query) - 1; i++) {
         tablet->query[tablet->query_index++] = buf[i];
     }
     tablet->query[tablet->query_index] = 0;

     while (tablet->query_index > 0 && (tablet->query[0] == '@'  ||
                                        tablet->query[0] == '\r' ||
                                        tablet->query[0] == '\n')) {
         wctablet_shift_input(tablet, 1);
     }
     if (!tablet->query_index) {
         return len;
     }

     if (strncmp((char *)tablet->query, "~#", 2) == 0) {
         /* init / detect sequence */
         trace_wct_init();
         wctablet_shift_input(tablet, 2);
         wctablet_queue_output(tablet, WC_MODEL_STRING,
                               WC_MODEL_STRING_LENGTH);
         return len;
     }

     /* detect line */
     pos = strchr((char *)tablet->query, '\r');
     if (!pos) {
         pos = strchr((char *)tablet->query, '\n');
     }
     if (!pos) {
         return len;
     }
     clen = pos - (char *)tablet->query;

     /* process commands */
     if (strncmp((char *)tablet->query, "RE", 2) == 0 &&
         clen == 2) {
         trace_wct_cmd_re();
         wctablet_shift_input(tablet, 3);
         wctablet_queue_output(tablet, WC_CONFIG_STRING,
                               WC_CONFIG_STRING_LENGTH);

     } else if (strncmp((char *)tablet->query, "ST", 2) == 0 &&
                clen == 2) {
         trace_wct_cmd_st();
         wctablet_shift_input(tablet, 3);
         tablet->send_events = true;
         wctablet_queue_event(tablet);

     } else if (strncmp((char *)tablet->query, "SP", 2) == 0 &&
                clen == 2) {
         trace_wct_cmd_sp();
         wctablet_shift_input(tablet, 3);
         tablet->send_events = false;

     } else if (strncmp((char *)tablet->query, "TS", 2) == 0 &&
                clen == 3) {
         unsigned int input = tablet->query[2];
         uint8_t codes[7] = {
             0xa3,
             ((input & 0x80) == 0) ? 0x7e : 0x7f,
             (((WC_H4(input) & 0x7) ^ 0x5) << 4) | (WC_L4(input) ^ 0x7),
             0x03,
             0x7f,
             0x7f,
             0x00,
         };
         trace_wct_cmd_ts(input);
         wctablet_shift_input(tablet, 4);
         wctablet_queue_output(tablet, codes, 7);

     } else {
         tablet->query[clen] = 0; /* terminate line for printing */
         trace_wct_cmd_other((char *)tablet->query);
         wctablet_shift_input(tablet, clen + 1);

     }

     return len;
 }

 static int wctablet_chr_ioctl(Chardev *chr, int cmd, void *arg)
 {
     TabletChardev *tablet = WCTABLET_CHARDEV(chr);
     QEMUSerialSetParams *ssp;

     switch (cmd) {
     case CHR_IOCTL_SERIAL_SET_PARAMS:
         ssp = arg;
         if (tablet->line_speed != ssp->speed) {
             trace_wct_speed(ssp->speed);
             wctablet_reset(tablet);
             tablet->line_speed = ssp->speed;
         }
         break;
     default:
         return -ENOTSUP;
     }
     return 0;
 }

 static void wctablet_chr_finalize(Object *obj)
 {
     TabletChardev *tablet = WCTABLET_CHARDEV(obj);

     qemu_input_handler_unregister(tablet->hs);
     g_free(tablet);
 }

 static void wctablet_chr_open(Chardev *chr,
                               ChardevBackend *backend,
                               bool *be_opened,
                               Error **errp)
 {
     TabletChardev *tablet = WCTABLET_CHARDEV(chr);

     *be_opened = true;

     /* init state machine */
     memcpy(tablet->outbuf, WC_FULL_CONFIG_STRING, WC_FULL_CONFIG_STRING_LENGTH);
     tablet->outlen = WC_FULL_CONFIG_STRING_LENGTH;
     tablet->query_index = 0;

     tablet->hs = qemu_input_handler_register((DeviceState *)tablet,
                                              &wctablet_handler);
 }

 static void wctablet_chr_class_init(ObjectClass *oc, void *data)
 {
     ChardevClass *cc = CHARDEV_CLASS(oc);

     cc->open = wctablet_chr_open;
     cc->chr_write = wctablet_chr_write;
     cc->chr_ioctl = wctablet_chr_ioctl;
     cc->chr_accept_input = wctablet_chr_accept_input;
 }

 static const TypeInfo wctablet_type_info = {
     .name = TYPE_CHARDEV_WCTABLET,
     .parent = TYPE_CHARDEV,
     .instance_size = sizeof(TabletChardev),
     .instance_finalize = wctablet_chr_finalize,
     .class_init = wctablet_chr_class_init,
 };

 static void register_types(void)
 {
      type_register_static(&wctablet_type_info);
 }

 type_init(register_types);
	/*
	* QEMU Wacom Penpartner serial tablet emulation
	*
	* some protocol details:
	* http://linuxwacom.sourceforge.net/wiki/index.php/Serial_Protocol_IV
	*
	* Copyright (c) 2016 Anatoli Huseu1
	* Copyright (c) 2016,17 Gerd Hoffmann
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to
	* deal in the Software without restriction, including without limitation
	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

	#include "qemu/osdep.h"
	#include "qemu/module.h"
	#include "chardev/char-serial.h"
	#include "ui/console.h"
	#include "ui/input.h"
	#include "trace.h"
	#include "qom/object.h"


	#define WC_OUTPUT_BUF_MAX_LEN 512
	#define WC_COMMAND_MAX_LEN 60

	#define WC_L7(n) ((n) & 127)
	#define WC_M7(n) (((n) >> 7) & 127)
	#define WC_H2(n) ((n) >> 14)

	#define WC_L4(n) ((n) & 15)
	#define WC_H4(n) (((n) >> 4) & 15)

	/* Model string and config string */
	#define WC_MODEL_STRING_LENGTH 18
	uint8_t WC_MODEL_STRING[WC_MODEL_STRING_LENGTH + 1] = "~#CT-0045R,V1.3-5,";

	#define WC_CONFIG_STRING_LENGTH 8
	uint8_t WC_CONFIG_STRING[WC_CONFIG_STRING_LENGTH + 1] = "96,N,8,0";

	#define WC_FULL_CONFIG_STRING_LENGTH 61
	uint8_t WC_FULL_CONFIG_STRING[WC_FULL_CONFIG_STRING_LENGTH + 1] = {
	0x5c, 0x39, 0x36, 0x2c, 0x4e, 0x2c, 0x38, 0x2c,
	0x31, 0x28, 0x01, 0x24, 0x57, 0x41, 0x43, 0x30,
	0x30, 0x34, 0x35, 0x5c, 0x5c, 0x50, 0x45, 0x4e, 0x5c,
	0x57, 0x41, 0x43, 0x30, 0x30, 0x30, 0x30, 0x5c,
	0x54, 0x61, 0x62, 0x6c, 0x65, 0x74, 0x0d, 0x0a,
	0x43, 0x54, 0x2d, 0x30, 0x30, 0x34, 0x35, 0x52,
	0x2c, 0x56, 0x31, 0x2e, 0x33, 0x2d, 0x35, 0x0d,
	0x0a, 0x45, 0x37, 0x29
	};

	/* This structure is used to save private info for Wacom Tablet. */
	struct TabletChardev {
	Chardev parent;
	QemuInputHandlerState *hs;

	/* Query string from serial */
	uint8_t query[100];
	int query_index;

	/* Command to be sent to serial port */
	uint8_t outbuf[WC_OUTPUT_BUF_MAX_LEN];
	int outlen;

	int line_speed;
	bool send_events;
	int axis[INPUT_AXIS__MAX];
	bool btns[INPUT_BUTTON__MAX];

	};
	typedef struct TabletChardev TabletChardev;

	#define TYPE_CHARDEV_WCTABLET "chardev-wctablet"
	DECLARE_INSTANCE_CHECKER(TabletChardev, WCTABLET_CHARDEV,
	TYPE_CHARDEV_WCTABLET)


	static void wctablet_chr_accept_input(Chardev *chr);

	static void wctablet_shift_input(TabletChardev *tablet, int count)
	{
	tablet->query_index -= count;
	memmove(tablet->query, tablet->query + count, tablet->query_index);
	tablet->query[tablet->query_index] = 0;
	}

	static void wctablet_queue_output(TabletChardev tablet, uint8_t buf, int count)
	{
	if (tablet->outlen + count > sizeof(tablet->outbuf)) {
	return;
	}

	memcpy(tablet->outbuf + tablet->outlen, buf, count);
	tablet->outlen += count;
	wctablet_chr_accept_input(CHARDEV(tablet));
	}

	static void wctablet_reset(TabletChardev *tablet)
	{
	/* clear buffers */
	tablet->query_index = 0;
	tablet->outlen = 0;
	/* reset state */
	tablet->send_events = false;
	}

	static void wctablet_queue_event(TabletChardev *tablet)
	{
	uint8_t codes[8] = { 0xe0, 0, 0, 0, 0, 0, 0 };

	if (tablet->line_speed != 9600) {
	return;
	}

	int newX = tablet->axis[INPUT_AXIS_X] * 0.1537;
	int nexY = tablet->axis[INPUT_AXIS_Y] * 0.1152;

	codes[0] = codes[0] \| WC_H2(newX);
	codes[1] = codes[1] \| WC_M7(newX);
	codes[2] = codes[2] \| WC_L7(newX);

	codes[3] = codes[3] \| WC_H2(nexY);
	codes[4] = codes[4] \| WC_M7(nexY);
	codes[5] = codes[5] \| WC_L7(nexY);

	if (tablet->btns[INPUT_BUTTON_LEFT]) {
	codes[0] = 0xa0;
	}

	wctablet_queue_output(tablet, codes, 7);
	}

	static void wctablet_input_event(DeviceState dev, QemuConsole src,
	InputEvent *evt)
	{
	TabletChardev tablet = (TabletChardev )dev;
	InputMoveEvent *move;
	InputBtnEvent *btn;

	switch (evt->type) {
	case INPUT_EVENT_KIND_ABS:
	move = evt->u.abs.data;
	tablet->axis[move->axis] = move->value;
	break;

	case INPUT_EVENT_KIND_BTN:
	btn = evt->u.btn.data;
	tablet->btns[btn->button] = btn->down;
	break;

	default:
	/* keep gcc happy */
	break;
	}
	}

	static void wctablet_input_sync(DeviceState *dev)
	{
	TabletChardev tablet = (TabletChardev )dev;

	if (tablet->send_events) {
	wctablet_queue_event(tablet);
	}
	}

	static QemuInputHandler wctablet_handler = {
	.name = "QEMU Wacom Pen Tablet",
	.mask = INPUT_EVENT_MASK_BTN \| INPUT_EVENT_MASK_ABS,
	.event = wctablet_input_event,
	.sync = wctablet_input_sync,
	};

	static void wctablet_chr_accept_input(Chardev *chr)
	{
	TabletChardev *tablet = WCTABLET_CHARDEV(chr);
	int len, canWrite;

	canWrite = qemu_chr_be_can_write(chr);
	len = canWrite;
	if (len > tablet->outlen) {
	len = tablet->outlen;
	}

	if (len) {
	qemu_chr_be_write(chr, tablet->outbuf, len);
	tablet->outlen -= len;
	if (tablet->outlen) {
	memmove(tablet->outbuf, tablet->outbuf + len, tablet->outlen);
	}
	}
	}

	static int wctablet_chr_write(struct Chardev *chr,
	const uint8_t *buf, int len)
	{
	TabletChardev *tablet = WCTABLET_CHARDEV(chr);
	unsigned int i, clen;
	char *pos;

	if (tablet->line_speed != 9600) {
	return len;
	}
	for (i = 0; i < len && tablet->query_index < sizeof(tablet->query) - 1; i++) {
	tablet->query[tablet->query_index++] = buf[i];
	}
	tablet->query[tablet->query_index] = 0;

	while (tablet->query_index > 0 && (tablet->query[0] == '@' \|\|
	tablet->query[0] == '\r' \|\|
	tablet->query[0] == '\n')) {
	wctablet_shift_input(tablet, 1);
	}
	if (!tablet->query_index) {
	return len;
	}

	if (strncmp((char *)tablet->query, "~#", 2) == 0) {
	/* init / detect sequence */
	trace_wct_init();
	wctablet_shift_input(tablet, 2);
	wctablet_queue_output(tablet, WC_MODEL_STRING,
	WC_MODEL_STRING_LENGTH);
	return len;
	}

	/* detect line */
	pos = strchr((char *)tablet->query, '\r');
	if (!pos) {
	pos = strchr((char *)tablet->query, '\n');
	}
	if (!pos) {
	return len;
	}
	clen = pos - (char *)tablet->query;

	/* process commands */
	if (strncmp((char *)tablet->query, "RE", 2) == 0 &&
	clen == 2) {
	trace_wct_cmd_re();
	wctablet_shift_input(tablet, 3);
	wctablet_queue_output(tablet, WC_CONFIG_STRING,
	WC_CONFIG_STRING_LENGTH);

	} else if (strncmp((char *)tablet->query, "ST", 2) == 0 &&
	clen == 2) {
	trace_wct_cmd_st();
	wctablet_shift_input(tablet, 3);
	tablet->send_events = true;
	wctablet_queue_event(tablet);

	} else if (strncmp((char *)tablet->query, "SP", 2) == 0 &&
	clen == 2) {
	trace_wct_cmd_sp();
	wctablet_shift_input(tablet, 3);
	tablet->send_events = false;

	} else if (strncmp((char *)tablet->query, "TS", 2) == 0 &&
	clen == 3) {
	unsigned int input = tablet->query[2];
	uint8_t codes[7] = {
	0xa3,
	((input & 0x80) == 0) ? 0x7e : 0x7f,
	(((WC_H4(input) & 0x7) ^ 0x5) << 4) \| (WC_L4(input) ^ 0x7),
	0x03,
	0x7f,
	0x7f,
	0x00,
	};
	trace_wct_cmd_ts(input);
	wctablet_shift_input(tablet, 4);
	wctablet_queue_output(tablet, codes, 7);

	} else {
	tablet->query[clen] = 0; /* terminate line for printing */
	trace_wct_cmd_other((char *)tablet->query);
	wctablet_shift_input(tablet, clen + 1);

	}

	return len;
	}

	static int wctablet_chr_ioctl(Chardev chr, int cmd, void arg)
	{
	TabletChardev *tablet = WCTABLET_CHARDEV(chr);
	QEMUSerialSetParams *ssp;

	switch (cmd) {
	case CHR_IOCTL_SERIAL_SET_PARAMS:
	ssp = arg;
	if (tablet->line_speed != ssp->speed) {
	trace_wct_speed(ssp->speed);
	wctablet_reset(tablet);
	tablet->line_speed = ssp->speed;
	}
	break;
	default:
	return -ENOTSUP;
	}
	return 0;
	}

	static void wctablet_chr_finalize(Object *obj)
	{
	TabletChardev *tablet = WCTABLET_CHARDEV(obj);

	qemu_input_handler_unregister(tablet->hs);
	g_free(tablet);
	}

	static void wctablet_chr_open(Chardev *chr,
	ChardevBackend *backend,
	bool *be_opened,
	Error **errp)
	{
	TabletChardev *tablet = WCTABLET_CHARDEV(chr);

	*be_opened = true;

	/* init state machine */
	memcpy(tablet->outbuf, WC_FULL_CONFIG_STRING, WC_FULL_CONFIG_STRING_LENGTH);
	tablet->outlen = WC_FULL_CONFIG_STRING_LENGTH;
	tablet->query_index = 0;

	tablet->hs = qemu_input_handler_register((DeviceState *)tablet,
	&wctablet_handler);
	}

	static void wctablet_chr_class_init(ObjectClass oc, void data)
	{
	ChardevClass *cc = CHARDEV_CLASS(oc);

	cc->open = wctablet_chr_open;
	cc->chr_write = wctablet_chr_write;
	cc->chr_ioctl = wctablet_chr_ioctl;
	cc->chr_accept_input = wctablet_chr_accept_input;
	}

	static const TypeInfo wctablet_type_info = {
	.name = TYPE_CHARDEV_WCTABLET,
	.parent = TYPE_CHARDEV,
	.instance_size = sizeof(TabletChardev),
	.instance_finalize = wctablet_chr_finalize,
	.class_init = wctablet_chr_class_init,
	};

	static void register_types(void)
	{
	type_register_static(&wctablet_type_info);
	}

	type_init(register_types);