linux/drivers/input/touchscreen/mtouch.c
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   1/*
   2 * MicroTouch (3M) serial touchscreen driver
   3 *
   4 * Copyright (c) 2004 Vojtech Pavlik
   5 */
   6
   7/*
   8 * This program is free software; you can redistribute it and/or modify it
   9 * under the terms of the GNU General Public License version 2 as published by
  10 * the Free Software Foundation.
  11 */
  12
  13/*
  14 * 2005/02/19 Dan Streetman <ddstreet@ieee.org>
  15 *   Copied elo.c and edited for MicroTouch protocol
  16 */
  17
  18#include <linux/errno.h>
  19#include <linux/kernel.h>
  20#include <linux/module.h>
  21#include <linux/slab.h>
  22#include <linux/input.h>
  23#include <linux/serio.h>
  24
  25#define DRIVER_DESC     "MicroTouch serial touchscreen driver"
  26
  27MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  28MODULE_DESCRIPTION(DRIVER_DESC);
  29MODULE_LICENSE("GPL");
  30
  31/*
  32 * Definitions & global arrays.
  33 */
  34
  35#define MTOUCH_FORMAT_TABLET_STATUS_BIT 0x80
  36#define MTOUCH_FORMAT_TABLET_TOUCH_BIT 0x40
  37#define MTOUCH_FORMAT_TABLET_LENGTH 5
  38#define MTOUCH_RESPONSE_BEGIN_BYTE 0x01
  39#define MTOUCH_RESPONSE_END_BYTE 0x0d
  40
  41/* todo: check specs for max length of all responses */
  42#define MTOUCH_MAX_LENGTH 16
  43
  44#define MTOUCH_MIN_XC 0
  45#define MTOUCH_MAX_XC 0x3fff
  46#define MTOUCH_MIN_YC 0
  47#define MTOUCH_MAX_YC 0x3fff
  48
  49#define MTOUCH_GET_XC(data) (((data[2])<<7) | data[1])
  50#define MTOUCH_GET_YC(data) (((data[4])<<7) | data[3])
  51#define MTOUCH_GET_TOUCHED(data) (MTOUCH_FORMAT_TABLET_TOUCH_BIT & data[0])
  52
  53/*
  54 * Per-touchscreen data.
  55 */
  56
  57struct mtouch {
  58        struct input_dev *dev;
  59        struct serio *serio;
  60        int idx;
  61        unsigned char data[MTOUCH_MAX_LENGTH];
  62        char phys[32];
  63};
  64
  65static void mtouch_process_format_tablet(struct mtouch *mtouch)
  66{
  67        struct input_dev *dev = mtouch->dev;
  68
  69        if (MTOUCH_FORMAT_TABLET_LENGTH == ++mtouch->idx) {
  70                input_report_abs(dev, ABS_X, MTOUCH_GET_XC(mtouch->data));
  71                input_report_abs(dev, ABS_Y, MTOUCH_MAX_YC - MTOUCH_GET_YC(mtouch->data));
  72                input_report_key(dev, BTN_TOUCH, MTOUCH_GET_TOUCHED(mtouch->data));
  73                input_sync(dev);
  74
  75                mtouch->idx = 0;
  76        }
  77}
  78
  79static void mtouch_process_response(struct mtouch *mtouch)
  80{
  81        if (MTOUCH_RESPONSE_END_BYTE == mtouch->data[mtouch->idx++]) {
  82                /* FIXME - process response */
  83                mtouch->idx = 0;
  84        } else if (MTOUCH_MAX_LENGTH == mtouch->idx) {
  85                printk(KERN_ERR "mtouch.c: too many response bytes\n");
  86                mtouch->idx = 0;
  87        }
  88}
  89
  90static irqreturn_t mtouch_interrupt(struct serio *serio,
  91                unsigned char data, unsigned int flags)
  92{
  93        struct mtouch* mtouch = serio_get_drvdata(serio);
  94
  95        mtouch->data[mtouch->idx] = data;
  96
  97        if (MTOUCH_FORMAT_TABLET_STATUS_BIT & mtouch->data[0])
  98                mtouch_process_format_tablet(mtouch);
  99        else if (MTOUCH_RESPONSE_BEGIN_BYTE == mtouch->data[0])
 100                mtouch_process_response(mtouch);
 101        else
 102                printk(KERN_DEBUG "mtouch.c: unknown/unsynchronized data from device, byte %x\n",mtouch->data[0]);
 103
 104        return IRQ_HANDLED;
 105}
 106
 107/*
 108 * mtouch_disconnect() is the opposite of mtouch_connect()
 109 */
 110
 111static void mtouch_disconnect(struct serio *serio)
 112{
 113        struct mtouch* mtouch = serio_get_drvdata(serio);
 114
 115        input_get_device(mtouch->dev);
 116        input_unregister_device(mtouch->dev);
 117        serio_close(serio);
 118        serio_set_drvdata(serio, NULL);
 119        input_put_device(mtouch->dev);
 120        kfree(mtouch);
 121}
 122
 123/*
 124 * mtouch_connect() is the routine that is called when someone adds a
 125 * new serio device that supports MicroTouch (Format Tablet) protocol and registers it as
 126 * an input device.
 127 */
 128
 129static int mtouch_connect(struct serio *serio, struct serio_driver *drv)
 130{
 131        struct mtouch *mtouch;
 132        struct input_dev *input_dev;
 133        int err;
 134
 135        mtouch = kzalloc(sizeof(struct mtouch), GFP_KERNEL);
 136        input_dev = input_allocate_device();
 137        if (!mtouch || !input_dev) {
 138                err = -ENOMEM;
 139                goto fail1;
 140        }
 141
 142        mtouch->serio = serio;
 143        mtouch->dev = input_dev;
 144        snprintf(mtouch->phys, sizeof(mtouch->phys), "%s/input0", serio->phys);
 145
 146        input_dev->name = "MicroTouch Serial TouchScreen";
 147        input_dev->phys = mtouch->phys;
 148        input_dev->id.bustype = BUS_RS232;
 149        input_dev->id.vendor = SERIO_MICROTOUCH;
 150        input_dev->id.product = 0;
 151        input_dev->id.version = 0x0100;
 152        input_dev->dev.parent = &serio->dev;
 153        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 154        input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 155        input_set_abs_params(mtouch->dev, ABS_X, MTOUCH_MIN_XC, MTOUCH_MAX_XC, 0, 0);
 156        input_set_abs_params(mtouch->dev, ABS_Y, MTOUCH_MIN_YC, MTOUCH_MAX_YC, 0, 0);
 157
 158        serio_set_drvdata(serio, mtouch);
 159
 160        err = serio_open(serio, drv);
 161        if (err)
 162                goto fail2;
 163
 164        err = input_register_device(mtouch->dev);
 165        if (err)
 166                goto fail3;
 167
 168        return 0;
 169
 170 fail3: serio_close(serio);
 171 fail2: serio_set_drvdata(serio, NULL);
 172 fail1: input_free_device(input_dev);
 173        kfree(mtouch);
 174        return err;
 175}
 176
 177/*
 178 * The serio driver structure.
 179 */
 180
 181static const struct serio_device_id mtouch_serio_ids[] = {
 182        {
 183                .type   = SERIO_RS232,
 184                .proto  = SERIO_MICROTOUCH,
 185                .id     = SERIO_ANY,
 186                .extra  = SERIO_ANY,
 187        },
 188        { 0 }
 189};
 190
 191MODULE_DEVICE_TABLE(serio, mtouch_serio_ids);
 192
 193static struct serio_driver mtouch_drv = {
 194        .driver         = {
 195                .name   = "mtouch",
 196        },
 197        .description    = DRIVER_DESC,
 198        .id_table       = mtouch_serio_ids,
 199        .interrupt      = mtouch_interrupt,
 200        .connect        = mtouch_connect,
 201        .disconnect     = mtouch_disconnect,
 202};
 203
 204module_serio_driver(mtouch_drv);
 205