inexio.c

   1 /*
   2  * iNexio serial touchscreen driver
   3  *
   4  * Copyright (c) 2008 Richard Lemon
   5  * Based on the mtouch driver (c) Vojtech Pavlik and Dan Streetman
   6  *
   7  */
   8
   9 /*
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License version 2 as published by
  12  * the Free Software Foundation.
  13  */
  14
  15 /*
  16  * 2008/06/19 Richard Lemon <richard@codelemon.com>
  17  *   Copied mtouch.c and edited for iNexio protocol
  18  */
  19
  20 #include <linux/errno.h>
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/slab.h>
  24 #include <linux/input.h>
  25 #include <linux/serio.h>
  26 #include <linux/init.h>
  27
  28 #define DRIVER_DESC     "iNexio serial touchscreen driver"
  29
  30 MODULE_AUTHOR("Richard Lemon <richard@codelemon.com>");
  31 MODULE_DESCRIPTION(DRIVER_DESC);
  32 MODULE_LICENSE("GPL");
  33
  34 /*
  35  * Definitions & global arrays.
  36  */
  37
  38 #define INEXIO_FORMAT_TOUCH_BIT 0x01
  39 #define INEXIO_FORMAT_LENGTH 5
  40 #define INEXIO_RESPONSE_BEGIN_BYTE 0x80
  41
  42 /* todo: check specs for max length of all responses */
  43 #define INEXIO_MAX_LENGTH 16
  44
  45 #define INEXIO_MIN_XC 0
  46 #define INEXIO_MAX_XC 0x3fff
  47 #define INEXIO_MIN_YC 0
  48 #define INEXIO_MAX_YC 0x3fff
  49
  50 #define INEXIO_GET_XC(data) (((data[1])<<7) | data[2])
  51 #define INEXIO_GET_YC(data) (((data[3])<<7) | data[4])
  52 #define INEXIO_GET_TOUCHED(data) (INEXIO_FORMAT_TOUCH_BIT & data[0])
  53
  54 /*
  55  * Per-touchscreen data.
  56  */
  57
  58 struct inexio {
  59         struct input_dev *dev;
  60         struct serio *serio;
  61         int idx;
  62         unsigned char data[INEXIO_MAX_LENGTH];
  63         char phys[32];
  64 };
  65
  66 static void inexio_process_data(struct inexio *pinexio)
  67 {
  68         struct input_dev *dev = pinexio->dev;
  69
  70         if (INEXIO_FORMAT_LENGTH == ++pinexio->idx) {
  71                 input_report_abs(dev, ABS_X, INEXIO_GET_XC(pinexio->data));
  72                 input_report_abs(dev, ABS_Y, INEXIO_GET_YC(pinexio->data));
  73                 input_report_key(dev, BTN_TOUCH, INEXIO_GET_TOUCHED(pinexio->data));
  74                 input_sync(dev);
  75
  76                 pinexio->idx = 0;
  77         }
  78 }
  79
  80 static irqreturn_t inexio_interrupt(struct serio *serio,
  81                 unsigned char data, unsigned int flags)
  82 {
  83         struct inexio* pinexio = serio_get_drvdata(serio);
  84
  85         pinexio->data[pinexio->idx] = data;
  86
  87         if (INEXIO_RESPONSE_BEGIN_BYTE&pinexio->data[0])
  88                 inexio_process_data(pinexio);
  89         else
  90                 printk(KERN_DEBUG "inexio.c: unknown/unsynchronized data from device, byte %x\n",pinexio->data[0]);
  91
  92         return IRQ_HANDLED;
  93 }
  94
  95 /*
  96  * inexio_disconnect() is the opposite of inexio_connect()
  97  */
  98
  99 static void inexio_disconnect(struct serio *serio)
 100 {
 101         struct inexio* pinexio = serio_get_drvdata(serio);
 102
 103         input_get_device(pinexio->dev);
 104         input_unregister_device(pinexio->dev);
 105         serio_close(serio);
 106         serio_set_drvdata(serio, NULL);
 107         input_put_device(pinexio->dev);
 108         kfree(pinexio);
 109 }
 110
 111 /*
 112  * inexio_connect() is the routine that is called when someone adds a
 113  * new serio device that supports iNexio protocol and registers it as
 114  * an input device. This is usually accomplished using inputattach.
 115  */
 116
 117 static int inexio_connect(struct serio *serio, struct serio_driver *drv)
 118 {
 119         struct inexio *pinexio;
 120         struct input_dev *input_dev;
 121         int err;
 122
 123         pinexio = kzalloc(sizeof(struct inexio), GFP_KERNEL);
 124         input_dev = input_allocate_device();
 125         if (!pinexio || !input_dev) {
 126                 err = -ENOMEM;
 127                 goto fail1;
 128         }
 129
 130         pinexio->serio = serio;
 131         pinexio->dev = input_dev;
 132         snprintf(pinexio->phys, sizeof(pinexio->phys), "%s/input0", serio->phys);
 133
 134         input_dev->name = "iNexio Serial TouchScreen";
 135         input_dev->phys = pinexio->phys;
 136         input_dev->id.bustype = BUS_RS232;
 137         input_dev->id.vendor = SERIO_INEXIO;
 138         input_dev->id.product = 0;
 139         input_dev->id.version = 0x0001;
 140         input_dev->dev.parent = &serio->dev;
 141         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 142         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 143         input_set_abs_params(pinexio->dev, ABS_X, INEXIO_MIN_XC, INEXIO_MAX_XC, 0, 0);
 144         input_set_abs_params(pinexio->dev, ABS_Y, INEXIO_MIN_YC, INEXIO_MAX_YC, 0, 0);
 145
 146         serio_set_drvdata(serio, pinexio);
 147
 148         err = serio_open(serio, drv);
 149         if (err)
 150                 goto fail2;
 151
 152         err = input_register_device(pinexio->dev);
 153         if (err)
 154                 goto fail3;
 155
 156         return 0;
 157
 158  fail3: serio_close(serio);
 159  fail2: serio_set_drvdata(serio, NULL);
 160  fail1: input_free_device(input_dev);
 161         kfree(pinexio);
 162         return err;
 163 }
 164
 165 /*
 166  * The serio driver structure.
 167  */
 168
 169 static struct serio_device_id inexio_serio_ids[] = {
 170         {
 171                 .type   = SERIO_RS232,
 172                 .proto  = SERIO_INEXIO,
 173                 .id     = SERIO_ANY,
 174                 .extra  = SERIO_ANY,
 175         },
 176         { 0 }
 177 };
 178
 179 MODULE_DEVICE_TABLE(serio, inexio_serio_ids);
 180
 181 static struct serio_driver inexio_drv = {
 182         .driver         = {
 183                 .name   = "inexio",
 184         },
 185         .description    = DRIVER_DESC,
 186         .id_table       = inexio_serio_ids,
 187         .interrupt      = inexio_interrupt,
 188         .connect        = inexio_connect,
 189         .disconnect     = inexio_disconnect,
 190 };
 191
 192 /*
 193  * The functions for inserting/removing us as a module.
 194  */
 195
 196 static int __init inexio_init(void)
 197 {
 198         return serio_register_driver(&inexio_drv);
 199 }
 200
 201 static void __exit inexio_exit(void)
 202 {
 203         serio_unregister_driver(&inexio_drv);
 204 }
 205
 206 module_init(inexio_init);
 207 module_exit(inexio_exit);