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