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, struct pt_regs *regs)
  67 {
  68         struct input_dev *dev = mtouch->dev;
  69
  70         if (MTOUCH_FORMAT_TABLET_LENGTH == ++mtouch->idx) {
  71                 input_regs(dev, regs);
  72                 input_report_abs(dev, ABS_X, MTOUCH_GET_XC(mtouch->data));
  73                 input_report_abs(dev, ABS_Y, MTOUCH_MAX_YC - MTOUCH_GET_YC(mtouch->data));
  74                 input_report_key(dev, BTN_TOUCH, MTOUCH_GET_TOUCHED(mtouch->data));
  75                 input_sync(dev);
  76
  77                 mtouch->idx = 0;
  78         }
  79 }
  80
  81 static void mtouch_process_response(struct mtouch *mtouch, struct pt_regs *regs)
  82 {
  83         if (MTOUCH_RESPONSE_END_BYTE == mtouch->data[mtouch->idx++]) {
  84                 /* FIXME - process response */
  85                 mtouch->idx = 0;
  86         } else if (MTOUCH_MAX_LENGTH == mtouch->idx) {
  87                 printk(KERN_ERR "mtouch.c: too many response bytes\n");
  88                 mtouch->idx = 0;
  89         }
  90 }
  91
  92 static irqreturn_t mtouch_interrupt(struct serio *serio,
  93                 unsigned char data, unsigned int flags, struct pt_regs *regs)
  94 {
  95         struct mtouch* mtouch = serio_get_drvdata(serio);
  96
  97         mtouch->data[mtouch->idx] = data;
  98
  99         if (MTOUCH_FORMAT_TABLET_STATUS_BIT & mtouch->data[0])
 100                 mtouch_process_format_tablet(mtouch, regs);
 101         else if (MTOUCH_RESPONSE_BEGIN_BYTE == mtouch->data[0])
 102                 mtouch_process_response(mtouch, regs);
 103         else
 104                 printk(KERN_DEBUG "mtouch.c: unknown/unsynchronized data from device, byte %x\n",mtouch->data[0]);
 105
 106         return IRQ_HANDLED;
 107 }
 108
 109 /*
 110  * mtouch_disconnect() is the opposite of mtouch_connect()
 111  */
 112
 113 static void mtouch_disconnect(struct serio *serio)
 114 {
 115         struct mtouch* mtouch = serio_get_drvdata(serio);
 116
 117         input_get_device(mtouch->dev);
 118         input_unregister_device(mtouch->dev);
 119         serio_close(serio);
 120         serio_set_drvdata(serio, NULL);
 121         input_put_device(mtouch->dev);
 122         kfree(mtouch);
 123 }
 124
 125 /*
 126  * mtouch_connect() is the routine that is called when someone adds a
 127  * new serio device that supports MicroTouch (Format Tablet) protocol and registers it as
 128  * an input device.
 129  */
 130
 131 static int mtouch_connect(struct serio *serio, struct serio_driver *drv)
 132 {
 133         struct mtouch *mtouch;
 134         struct input_dev *input_dev;
 135         int err;
 136
 137         mtouch = kzalloc(sizeof(struct mtouch), GFP_KERNEL);
 138         input_dev = input_allocate_device();
 139         if (!mtouch || !input_dev) {
 140                 err = -ENOMEM;
 141                 goto fail;
 142         }
 143
 144         mtouch->serio = serio;
 145         mtouch->dev = input_dev;
 146         snprintf(mtouch->phys, sizeof(mtouch->phys), "%s/input0", serio->phys);
 147
 148         input_dev->private = mtouch;
 149         input_dev->name = "MicroTouch Serial TouchScreen";
 150         input_dev->phys = mtouch->phys;
 151         input_dev->id.bustype = BUS_RS232;
 152         input_dev->id.vendor = SERIO_MICROTOUCH;
 153         input_dev->id.product = 0;
 154         input_dev->id.version = 0x0100;
 155         input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
 156         input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
 157         input_set_abs_params(mtouch->dev, ABS_X, MTOUCH_MIN_XC, MTOUCH_MAX_XC, 0, 0);
 158         input_set_abs_params(mtouch->dev, ABS_Y, MTOUCH_MIN_YC, MTOUCH_MAX_YC, 0, 0);
 159
 160         serio_set_drvdata(serio, mtouch);
 161
 162         err = serio_open(serio, drv);
 163         if (err)
 164                 goto fail;
 165
 166         input_register_device(mtouch->dev);
 167
 168         return 0;
 169
 170  fail:  serio_set_drvdata(serio, NULL);
 171         input_free_device(input_dev);
 172         kfree(mtouch);
 173         return err;
 174 }
 175
 176 /*
 177  * The serio driver structure.
 178  */
 179
 180 static struct serio_device_id mtouch_serio_ids[] = {
 181         {
 182                 .type   = SERIO_RS232,
 183                 .proto  = SERIO_MICROTOUCH,
 184                 .id     = SERIO_ANY,
 185                 .extra  = SERIO_ANY,
 186         },
 187         { 0 }
 188 };
 189
 190 MODULE_DEVICE_TABLE(serio, mtouch_serio_ids);
 191
 192 static struct serio_driver mtouch_drv = {
 193         .driver         = {
 194                 .name   = "mtouch",
 195         },
 196         .description    = DRIVER_DESC,
 197         .id_table       = mtouch_serio_ids,
 198         .interrupt      = mtouch_interrupt,
 199         .connect        = mtouch_connect,
 200         .disconnect     = mtouch_disconnect,
 201 };
 202
 203 /*
 204  * The functions for inserting/removing us as a module.
 205  */
 206
 207 static int __init mtouch_init(void)
 208 {
 209         serio_register_driver(&mtouch_drv);
 210         return 0;
 211 }
 212
 213 static void __exit mtouch_exit(void)
 214 {
 215         serio_unregister_driver(&mtouch_drv);
 216 }
 217
 218 module_init(mtouch_init);
 219 module_exit(mtouch_exit);