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 #include <linux/init.h>
  25
  26 #define DRIVER_DESC     "MicroTouch serial touchscreen driver"
  27
  28 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  29 MODULE_DESCRIPTION(DRIVER_DESC);
  30 MODULE_LICENSE("GPL");
  31
  32 /*
  33  * Definitions & global arrays.
  34  */
  35
  36 #define MTOUCH_FORMAT_TABLET_STATUS_BIT 0x80
  37 #define MTOUCH_FORMAT_TABLET_TOUCH_BIT 0x40
  38 #define MTOUCH_FORMAT_TABLET_LENGTH 5
  39 #define MTOUCH_RESPONSE_BEGIN_BYTE 0x01
  40 #define MTOUCH_RESPONSE_END_BYTE 0x0d
  41
  42 /* todo: check specs for max length of all responses */
  43 #define MTOUCH_MAX_LENGTH 16
  44
  45 #define MTOUCH_MIN_XC 0
  46 #define MTOUCH_MAX_XC 0x3fff
  47 #define MTOUCH_MIN_YC 0
  48 #define MTOUCH_MAX_YC 0x3fff
  49
  50 #define MTOUCH_GET_XC(data) (((data[2])<<7) | data[1])
  51 #define MTOUCH_GET_YC(data) (((data[4])<<7) | data[3])
  52 #define MTOUCH_GET_TOUCHED(data) (MTOUCH_FORMAT_TABLET_TOUCH_BIT & data[0])
  53
  54 /*
  55  * Per-touchscreen data.
  56  */
  57
  58 struct mtouch {
  59         struct input_dev *dev;
  60         struct serio *serio;
  61         int idx;
  62         unsigned char data[MTOUCH_MAX_LENGTH];
  63         char phys[32];
  64 };
  65
  66 static void mtouch_process_format_tablet(struct mtouch *mtouch)
  67 {
  68         struct input_dev *dev = mtouch->dev;
  69
  70         if (MTOUCH_FORMAT_TABLET_LENGTH == ++mtouch->idx) {
  71                 input_report_abs(dev, ABS_X, MTOUCH_GET_XC(mtouch->data));
  72                 input_report_abs(dev, ABS_Y, MTOUCH_MAX_YC - MTOUCH_GET_YC(mtouch->data));
  73                 input_report_key(dev, BTN_TOUCH, MTOUCH_GET_TOUCHED(mtouch->data));
  74                 input_sync(dev);
  75
  76                 mtouch->idx = 0;
  77         }
  78 }
  79
  80 static void mtouch_process_response(struct mtouch *mtouch)
  81 {
  82         if (MTOUCH_RESPONSE_END_BYTE == mtouch->data[mtouch->idx++]) {
  83                 /* FIXME - process response */
  84                 mtouch->idx = 0;
  85         } else if (MTOUCH_MAX_LENGTH == mtouch->idx) {
  86                 printk(KERN_ERR "mtouch.c: too many response bytes\n");
  87                 mtouch->idx = 0;
  88         }
  89 }
  90
  91 static irqreturn_t mtouch_interrupt(struct serio *serio,
  92                 unsigned char data, unsigned int flags)
  93 {
  94         struct mtouch* mtouch = serio_get_drvdata(serio);
  95
  96         mtouch->data[mtouch->idx] = data;
  97
  98         if (MTOUCH_FORMAT_TABLET_STATUS_BIT & mtouch->data[0])
  99                 mtouch_process_format_tablet(mtouch);
 100         else if (MTOUCH_RESPONSE_BEGIN_BYTE == mtouch->data[0])
 101                 mtouch_process_response(mtouch);
 102         else
 103                 printk(KERN_DEBUG "mtouch.c: unknown/unsynchronized data from device, byte %x\n",mtouch->data[0]);
 104
 105         return IRQ_HANDLED;
 106 }
 107
 108 /*
 109  * mtouch_disconnect() is the opposite of mtouch_connect()
 110  */
 111
 112 static void mtouch_disconnect(struct serio *serio)
 113 {
 114         struct mtouch* mtouch = serio_get_drvdata(serio);
 115
 116         input_get_device(mtouch->dev);
 117         input_unregister_device(mtouch->dev);
 118         serio_close(serio);
 119         serio_set_drvdata(serio, NULL);
 120         input_put_device(mtouch->dev);
 121         kfree(mtouch);
 122 }
 123
 124 /*
 125  * mtouch_connect() is the routine that is called when someone adds a
 126  * new serio device that supports MicroTouch (Format Tablet) protocol and registers it as
 127  * an input device.
 128  */
 129
 130 static int mtouch_connect(struct serio *serio, struct serio_driver *drv)
 131 {
 132         struct mtouch *mtouch;
 133         struct input_dev *input_dev;
 134         int err;
 135
 136         mtouch = kzalloc(sizeof(struct mtouch), GFP_KERNEL);
 137         input_dev = input_allocate_device();
 138         if (!mtouch || !input_dev) {
 139                 err = -ENOMEM;
 140                 goto fail;
 141         }
 142
 143         mtouch->serio = serio;
 144         mtouch->dev = input_dev;
 145         snprintf(mtouch->phys, sizeof(mtouch->phys), "%s/input0", serio->phys);
 146
 147         input_dev->private = mtouch;
 148         input_dev->name = "MicroTouch Serial TouchScreen";
 149         input_dev->phys = mtouch->phys;
 150         input_dev->id.bustype = BUS_RS232;
 151         input_dev->id.vendor = SERIO_MICROTOUCH;
 152         input_dev->id.product = 0;
 153         input_dev->id.version = 0x0100;
 154         input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
 155         input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
 156         input_set_abs_params(mtouch->dev, ABS_X, MTOUCH_MIN_XC, MTOUCH_MAX_XC, 0, 0);
 157         input_set_abs_params(mtouch->dev, ABS_Y, MTOUCH_MIN_YC, MTOUCH_MAX_YC, 0, 0);
 158
 159         serio_set_drvdata(serio, mtouch);
 160
 161         err = serio_open(serio, drv);
 162         if (err)
 163                 goto fail;
 164
 165         input_register_device(mtouch->dev);
 166
 167         return 0;
 168
 169  fail:  serio_set_drvdata(serio, NULL);
 170         input_free_device(input_dev);
 171         kfree(mtouch);
 172         return err;
 173 }
 174
 175 /*
 176  * The serio driver structure.
 177  */
 178
 179 static struct serio_device_id mtouch_serio_ids[] = {
 180         {
 181                 .type   = SERIO_RS232,
 182                 .proto  = SERIO_MICROTOUCH,
 183                 .id     = SERIO_ANY,
 184                 .extra  = SERIO_ANY,
 185         },
 186         { 0 }
 187 };
 188
 189 MODULE_DEVICE_TABLE(serio, mtouch_serio_ids);
 190
 191 static struct serio_driver mtouch_drv = {
 192         .driver         = {
 193                 .name   = "mtouch",
 194         },
 195         .description    = DRIVER_DESC,
 196         .id_table       = mtouch_serio_ids,
 197         .interrupt      = mtouch_interrupt,
 198         .connect        = mtouch_connect,
 199         .disconnect     = mtouch_disconnect,
 200 };
 201
 202 /*
 203  * The functions for inserting/removing us as a module.
 204  */
 205
 206 static int __init mtouch_init(void)
 207 {
 208         serio_register_driver(&mtouch_drv);
 209         return 0;
 210 }
 211
 212 static void __exit mtouch_exit(void)
 213 {
 214         serio_unregister_driver(&mtouch_drv);
 215 }
 216
 217 module_init(mtouch_init);
 218 module_exit(mtouch_exit);