wacom 手写笔linux驱动代码

/*

• Wacom protocol 4 serial tablet driver
• This program is free software; you can redistribute it and/or modify it
• under the terms of the GNU General Public License as published by the
• Free Software Foundation; either version of 2 of the License, or (at your
• option) any later version. See the file COPYING in the main directory of
• this archive for more details.
• Many thanks to Bill Seremetis, without whom PenPartner support
• would not have been possible. Thanks to Patrick Mahoney.
• To do:
• • support pad buttons; (requires access to a model with pad buttons)
• • support (protocol 4-style) tilt (requires access to a > 1.4 rom model)
    */

/*

• Wacom serial protocol 4 documentation taken from linuxwacom-0.9.9 code,
• protocol 4 uses 7 or 9 byte of data in the following format:
• Byte 1
• bit 7 Sync bit always 1
• bit 6 Pointing device detected
• bit 5 Cursor = 0 / Stylus = 1
• bit 4 Reserved
• bit 3 1 if a button on the pointing device has been pressed
• bit 2 P0 (optional)
• bit 1 X15
• bit 0 X14
• Byte 2
• bit 7 Always 0
• bits 6-0 = X13 - X7
• Byte 3
• bit 7 Always 0
• bits 6-0 = X6 - X0
• Byte 4
• bit 7 Always 0
• bit 6 B3
• bit 5 B2
• bit 4 B1
• bit 3 B0
• bit 2 P1 (optional)
• bit 1 Y15
• bit 0 Y14
• Byte 5
• bit 7 Always 0
• bits 6-0 = Y13 - Y7
• Byte 6
• bit 7 Always 0
• bits 6-0 = Y6 - Y0
• Byte 7
• bit 7 Always 0
• bit 6 Sign of pressure data; or wheel-rel for cursor tool
• bit 5 P7; or REL1 for cursor tool
• bit 4 P6; or REL0 for cursor tool
• bit 3 P5
• bit 2 P4
• bit 1 P3
• bit 0 P2
• byte 8 and 9 are optional and present only
• in tilt mode.
• Byte 8
• bit 7 Always 0
• bit 6 Sign of tilt X
• bit 5 Xt6
• bit 4 Xt5
• bit 3 Xt4
• bit 2 Xt3
• bit 1 Xt2
• bit 0 Xt1
• Byte 9
• bit 7 Always 0
• bit 6 Sign of tilt Y
• bit 5 Yt6
• bit 4 Yt5
• bit 3 Yt4
• bit 2 Yt3
• bit 1 Yt2
• bit 0 Yt1
  */

#include <linux/completion.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/serio.h>
#include <linux/slab.h>
#include <linux/string.h>

MODULE_AUTHOR(“Julian Squires julian@cipht.net, Hans de Goede hdegoede@redhat.com”);
MODULE_DESCRIPTION(“Wacom protocol 4 serial tablet driver”);
MODULE_LICENSE(“GPL”);

#define REQUEST_MODEL_AND_ROM_VERSION “~#”
#define REQUEST_MAX_COORDINATES “~C\r”
#define REQUEST_CONFIGURATION_STRING “~R\r”
#define REQUEST_RESET_TO_PROTOCOL_IV “\r#”
/*

• Note: sending “\r$\r” causes at least the Digitizer II to send
• packets in ASCII instead of binary. “\r#” seems to undo that.
  */

#define COMMAND_START_SENDING_PACKETS “ST\r”
#define COMMAND_STOP_SENDING_PACKETS “SP\r”
#define COMMAND_MULTI_MODE_INPUT “MU1\r”
#define COMMAND_ORIGIN_IN_UPPER_LEFT “OC1\r”
#define COMM