drivers/input/touchscreen/touchwin.c

   1 /*
   2  * Touchwindow serial touchscreen driver
   3  *
   4  * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
   5  *
   6  * Based on MicroTouch driver (drivers/input/touchscreen/mtouch.c)
   7  * Copyright (c) 2004 Vojtech Pavlik
   8  * and Dan Streetman <ddstreet@ieee.org>
   9  */
  10
  11 /*
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU General Public License version 2 as published
  14  * by the Free Software Foundation.
  15  */
  16
  17 /*
  18  * 2005/02/19 Rick Koch:
  19  *   The Touchwindow I used is made by Edmark Corp. and
  20  *   constantly outputs a stream of 0's unless it is touched.
  21  *   It then outputs 3 bytes: X, Y, and a copy of Y.
  22  */
  23
  24 #include <linux/errno.h>
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/slab.h>
  28 #include <linux/input.h>
  29 #include <linux/serio.h>
  30
  31 #define DRIVER_DESC     "Touchwindow serial touchscreen driver"
  32
  33 MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
  34 MODULE_DESCRIPTION(DRIVER_DESC);
  35 MODULE_LICENSE("GPL");
  36
  37 /*
  38  * Definitions & global arrays.
  39  */
  40
  41 #define TW_LENGTH 3
  42
  43 #define TW_MIN_XC 0
  44 #define TW_MAX_XC 0xff
  45 #define TW_MIN_YC 0
  46 #define TW_MAX_YC 0xff
  47
  48 /*
  49  * Per-touchscreen data.
  50  */
  51
  52 struct tw {
  53         struct input_dev *dev;
  54         struct serio *serio;
  55         int idx;
  56         int touched;
  57         unsigned char data[TW_LENGTH];
  58         char phys[32];
  59 };
  60
  61 static irqreturn_t tw_interrupt(struct serio *serio,
  62                 unsigned char data, unsigned int flags)
  63 {
  64         struct tw *tw = serio_get_drvdata(serio);
  65         struct input_dev *dev = tw->dev;
  66
  67         if (data) {             /* touch */
  68                 tw->touched = 1;
  69                 tw->data[tw->idx++] = data;
  70                 /* verify length and that the two Y's are the same */
  71                 if (tw->idx == TW_LENGTH && tw->data[1] == tw->data[2]) {
  72                         input_report_abs(dev, ABS_X, tw->data[0]);
  73                         input_report_abs(dev, ABS_Y, tw->data[1]);
  74                         input_report_key(dev, BTN_TOUCH, 1);
  75                         input_sync(dev);
  76                         tw->idx = 0;
  77                 }
  78         } else if (tw->touched) {       /* untouch */
  79                 input_report_key(dev, BTN_TOUCH, 0);
  80                 input_sync(dev);
  81                 tw->idx = 0;
  82                 tw->touched = 0;
  83         }
  84
  85         return IRQ_HANDLED;
  86 }
  87
  88 /*
  89  * tw_disconnect() is the opposite of tw_connect()
  90  */
  91
  92 static void tw_disconnect(struct serio *serio)
  93 {
  94         struct tw *tw = serio_get_drvdata(serio);
  95
  96         input_get_device(tw->dev);
  97         input_unregister_device(tw->dev);
  98         serio_close(serio);
  99         serio_set_drvdata(serio, NULL);
 100         input_put_device(tw->dev);
 101         kfree(tw);
 102 }
 103
 104 /*
 105  * tw_connect() is the routine that is called when someone adds a
 106  * new serio device that supports the Touchwin protocol and registers it as
 107  * an input device.
 108  */
 109
 110 static int tw_connect(struct serio *serio, struct serio_driver *drv)
 111 {
 112         struct tw *tw;
 113         struct input_dev *input_dev;
 114         int err;
 115
 116         tw = kzalloc(sizeof(struct tw), GFP_KERNEL);
 117         input_dev = input_allocate_device();
 118         if (!tw || !input_dev) {
 119                 err = -ENOMEM;
 120                 goto fail1;
 121         }
 122
 123         tw->serio = serio;
 124         tw->dev = input_dev;
 125         snprintf(tw->phys, sizeof(tw->phys), "%s/input0", serio->phys);
 126
 127         input_dev->name = "Touchwindow Serial TouchScreen";
 128         input_dev->phys = tw->phys;
 129         input_dev->id.bustype = BUS_RS232;
 130         input_dev->id.vendor = SERIO_TOUCHWIN;
 131         input_dev->id.product = 0;
 132         input_dev->id.version = 0x0100;
 133         input_dev->dev.parent = &serio->dev;
 134         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 135         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 136         input_set_abs_params(tw->dev, ABS_X, TW_MIN_XC, TW_MAX_XC, 0, 0);
 137         input_set_abs_params(tw->dev, ABS_Y, TW_MIN_YC, TW_MAX_YC, 0, 0);
 138
 139         serio_set_drvdata(serio, tw);
 140
 141         err = serio_open(serio, drv);
 142         if (err)
 143                 goto fail2;
 144
 145         err = input_register_device(tw->dev);
 146         if (err)
 147                 goto fail3;
 148
 149         return 0;
 150
 151  fail3: serio_close(serio);
 152  fail2: serio_set_drvdata(serio, NULL);
 153  fail1: input_free_device(input_dev);
 154         kfree(tw);
 155         return err;
 156 }
 157
 158 /*
 159  * The serio driver structure.
 160  */
 161
 162 static struct serio_device_id tw_serio_ids[] = {
 163         {
 164                 .type   = SERIO_RS232,
 165                 .proto  = SERIO_TOUCHWIN,
 166                 .id     = SERIO_ANY,
 167                 .extra  = SERIO_ANY,
 168         },
 169         { 0 }
 170 };
 171
 172 MODULE_DEVICE_TABLE(serio, tw_serio_ids);
 173
 174 static struct serio_driver tw_drv = {
 175         .driver         = {
 176                 .name   = "touchwin",
 177         },
 178         .description    = DRIVER_DESC,
 179         .id_table       = tw_serio_ids,
 180         .interrupt      = tw_interrupt,
 181         .connect        = tw_connect,
 182         .disconnect     = tw_disconnect,
 183 };
 184
 185 module_serio_driver(tw_drv);