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 static char *mtouch_name = "MicroTouch Serial TouchScreen";
  55
  56 /*
  57  * Per-touchscreen data.
  58  */
  59
  60 struct mtouch {
  61         struct input_dev dev;
  62         struct serio *serio;
  63         int idx;
  64         unsigned char data[MTOUCH_MAX_LENGTH];
  65         char phys[32];
  66 };
  67
  68 static void mtouch_process_format_tablet(struct mtouch *mtouch, struct pt_regs *regs)
  69 {
  70         struct input_dev *dev = &mtouch->dev;
  71
  72         if (MTOUCH_FORMAT_TABLET_LENGTH == ++mtouch->idx) {
  73                 input_regs(dev, regs);
  74                 input_report_abs(dev, ABS_X, MTOUCH_GET_XC(mtouch->data));
  75                 input_report_abs(dev, ABS_Y, MTOUCH_MAX_YC - MTOUCH_GET_YC(mtouch->data));
  76                 input_report_key(dev, BTN_TOUCH, MTOUCH_GET_TOUCHED(mtouch->data));
  77                 input_sync(dev);
  78
  79                 mtouch->idx = 0;
  80         }
  81 }
  82
  83 static void mtouch_process_response(struct mtouch *mtouch, struct pt_regs *regs)
  84 {
  85         if (MTOUCH_RESPONSE_END_BYTE == mtouch->data[mtouch->idx++]) {
  86                 /* FIXME - process response */
  87                 mtouch->idx = 0;
  88         } else if (MTOUCH_MAX_LENGTH == mtouch->idx) {
  89                 printk(KERN_ERR "mtouch.c: too many response bytes\n");
  90                 mtouch->idx = 0;
  91         }
  92 }
  93
  94 static irqreturn_t mtouch_interrupt(struct serio *serio,
  95                 unsigned char data, unsigned int flags, struct pt_regs *regs)
  96 {
  97         struct mtouch* mtouch = serio_get_drvdata(serio);
  98
  99         mtouch->data[mtouch->idx] = data;
 100
 101         if (MTOUCH_FORMAT_TABLET_STATUS_BIT & mtouch->data[0])
 102                 mtouch_process_format_tablet(mtouch, regs);
 103         else if (MTOUCH_RESPONSE_BEGIN_BYTE == mtouch->data[0])
 104                 mtouch_process_response(mtouch, regs);
 105         else
 106                 printk(KERN_DEBUG "mtouch.c: unknown/unsynchronized data from device, byte %x\n",mtouch->data[0]);
 107
 108         return IRQ_HANDLED;
 109 }
 110
 111 /*
 112  * mtouch_disconnect() is the opposite of mtouch_connect()
 113  */
 114
 115 static void mtouch_disconnect(struct serio *serio)
 116 {
 117         struct mtouch* mtouch = serio_get_drvdata(serio);
 118
 119         input_unregister_device(&mtouch->dev);
 120         serio_close(serio);
 121         serio_set_drvdata(serio, NULL);
 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         int err;
 135
 136         if (!(mtouch = kmalloc(sizeof(*mtouch), GFP_KERNEL)))
 137                 return -ENOMEM;
 138
 139         memset(mtouch, 0, sizeof(*mtouch));
 140
 141         init_input_dev(&mtouch->dev);
 142         mtouch->dev.evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
 143         mtouch->dev.keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
 144
 145         input_set_abs_params(&mtouch->dev, ABS_X, MTOUCH_MIN_XC, MTOUCH_MAX_XC, 0, 0);
 146         input_set_abs_params(&mtouch->dev, ABS_Y, MTOUCH_MIN_YC, MTOUCH_MAX_YC, 0, 0);
 147
 148         mtouch->serio = serio;
 149
 150         sprintf(mtouch->phys, "%s/input0", serio->phys);
 151
 152         mtouch->dev.private = mtouch;
 153         mtouch->dev.name = mtouch_name;
 154         mtouch->dev.phys = mtouch->phys;
 155         mtouch->dev.id.bustype = BUS_RS232;
 156         mtouch->dev.id.vendor = SERIO_MICROTOUCH;
 157         mtouch->dev.id.product = 0;
 158         mtouch->dev.id.version = 0x0100;
 159
 160         serio_set_drvdata(serio, mtouch);
 161
 162         err = serio_open(serio, drv);
 163         if (err) {
 164                 serio_set_drvdata(serio, NULL);
 165                 kfree(mtouch);
 166                 return err;
 167         }
 168
 169         input_register_device(&mtouch->dev);
 170
 171         printk(KERN_INFO "input: %s on %s\n", mtouch->dev.name, serio->phys);
 172
 173         return 0;
 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);