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 #include <linux/init.h>
  31
  32 #define DRIVER_DESC     "Touchwindow serial touchscreen driver"
  33
  34 MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
  35 MODULE_DESCRIPTION(DRIVER_DESC);
  36 MODULE_LICENSE("GPL");
  37
  38 /*
  39  * Definitions & global arrays.
  40  */
  41
  42 #define TW_LENGTH 3
  43
  44 #define TW_MIN_XC 0
  45 #define TW_MAX_XC 0xff
  46 #define TW_MIN_YC 0
  47 #define TW_MAX_YC 0xff
  48
  49 /*
  50  * Per-touchscreen data.
  51  */
  52
  53 struct tw {
  54         struct input_dev *dev;
  55         struct serio *serio;
  56         int idx;
  57         int touched;
  58         unsigned char data[TW_LENGTH];
  59         char phys[32];
  60 };
  61
  62 static irqreturn_t tw_interrupt(struct serio *serio,
  63                 unsigned char data, unsigned int flags)
  64 {
  65         struct tw *tw = serio_get_drvdata(serio);
  66         struct input_dev *dev = tw->dev;
  67
  68         if (data) {             /* touch */
  69                 tw->touched = 1;
  70                 tw->data[tw->idx++] = data;
  71                 /* verify length and that the two Y's are the same */
  72                 if (tw->idx == TW_LENGTH && tw->data[1] == tw->data[2]) {
  73                         input_report_abs(dev, ABS_X, tw->data[0]);
  74                         input_report_abs(dev, ABS_Y, tw->data[1]);
  75                         input_report_key(dev, BTN_TOUCH, 1);
  76                         input_sync(dev);
  77                         tw->idx = 0;
  78                 }
  79         } else if (tw->touched) {       /* untouch */
  80                 input_report_key(dev, BTN_TOUCH, 0);
  81                 input_sync(dev);
  82                 tw->idx = 0;
  83                 tw->touched = 0;
  84         }
  85
  86         return IRQ_HANDLED;
  87 }
  88
  89 /*
  90  * tw_disconnect() is the opposite of tw_connect()
  91  */
  92
  93 static void tw_disconnect(struct serio *serio)
  94 {
  95         struct tw *tw = serio_get_drvdata(serio);
  96
  97         input_get_device(tw->dev);
  98         input_unregister_device(tw->dev);
  99         serio_close(serio);
 100         serio_set_drvdata(serio, NULL);
 101         input_put_device(tw->dev);
 102         kfree(tw);
 103 }
 104
 105 /*
 106  * tw_connect() is the routine that is called when someone adds a
 107  * new serio device that supports the Touchwin protocol and registers it as
 108  * an input device.
 109  */
 110
 111 static int tw_connect(struct serio *serio, struct serio_driver *drv)
 112 {
 113         struct tw *tw;
 114         struct input_dev *input_dev;
 115         int err;
 116
 117         tw = kzalloc(sizeof(struct tw), GFP_KERNEL);
 118         input_dev = input_allocate_device();
 119         if (!tw || !input_dev) {
 120                 err = -ENOMEM;
 121                 goto fail1;
 122         }
 123
 124         tw->serio = serio;
 125         tw->dev = input_dev;
 126         snprintf(tw->phys, sizeof(tw->phys), "%s/input0", serio->phys);
 127
 128         input_dev->private = tw;
 129         input_dev->name = "Touchwindow Serial TouchScreen";
 130         input_dev->phys = tw->phys;
 131         input_dev->id.bustype = BUS_RS232;
 132         input_dev->id.vendor = SERIO_TOUCHWIN;
 133         input_dev->id.product = 0;
 134         input_dev->id.version = 0x0100;
 135         input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
 136         input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
 137         input_set_abs_params(tw->dev, ABS_X, TW_MIN_XC, TW_MAX_XC, 0, 0);
 138         input_set_abs_params(tw->dev, ABS_Y, TW_MIN_YC, TW_MAX_YC, 0, 0);
 139
 140         serio_set_drvdata(serio, tw);
 141
 142         err = serio_open(serio, drv);
 143         if (err)
 144                 goto fail2;
 145
 146         err = input_register_device(tw->dev);
 147         if (err)
 148                 goto fail3;
 149
 150         return 0;
 151
 152  fail3: serio_close(serio);
 153  fail2: serio_set_drvdata(serio, NULL);
 154  fail1: input_free_device(input_dev);
 155         kfree(tw);
 156         return err;
 157 }
 158
 159 /*
 160  * The serio driver structure.
 161  */
 162
 163 static struct serio_device_id tw_serio_ids[] = {
 164         {
 165                 .type   = SERIO_RS232,
 166                 .proto  = SERIO_TOUCHWIN,
 167                 .id     = SERIO_ANY,
 168                 .extra  = SERIO_ANY,
 169         },
 170         { 0 }
 171 };
 172
 173 MODULE_DEVICE_TABLE(serio, tw_serio_ids);
 174
 175 static struct serio_driver tw_drv = {
 176         .driver         = {
 177                 .name   = "touchwin",
 178         },
 179         .description    = DRIVER_DESC,
 180         .id_table       = tw_serio_ids,
 181         .interrupt      = tw_interrupt,
 182         .connect        = tw_connect,
 183         .disconnect     = tw_disconnect,
 184 };
 185
 186 /*
 187  * The functions for inserting/removing us as a module.
 188  */
 189
 190 static int __init tw_init(void)
 191 {
 192         return serio_register_driver(&tw_drv);
 193 }
 194
 195 static void __exit tw_exit(void)
 196 {
 197         serio_unregister_driver(&tw_drv);
 198 }
 199
 200 module_init(tw_init);
 201 module_exit(tw_exit);