drivers/input/touchscreen/mtouch.c

   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
  27 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  28 MODULE_DESCRIPTION(DRIVER_DESC);
  29 MODULE_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
  57 struct 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
  65 static 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
  79 static 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
  90 static 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
 111 static 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
 129 static 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
 181 static 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
 191 MODULE_DEVICE_TABLE(serio, mtouch_serio_ids);
 192
 193 static 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
 204 module_serio_driver(mtouch_drv);