drivers/input/touchscreen/touchright.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Touchright serial touchscreen driver
   4  *
   5  * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
   6  *
   7  * Based on MicroTouch driver (drivers/input/touchscreen/mtouch.c)
   8  * Copyright (c) 2004 Vojtech Pavlik
   9  * and Dan Streetman <ddstreet@ieee.org>
  10  */
  11
  12
  13 #include <linux/errno.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17 #include <linux/input.h>
  18 #include <linux/serio.h>
  19
  20 #define DRIVER_DESC     "Touchright serial touchscreen driver"
  21
  22 MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
  23 MODULE_DESCRIPTION(DRIVER_DESC);
  24 MODULE_LICENSE("GPL");
  25
  26 /*
  27  * Definitions & global arrays.
  28  */
  29
  30 #define TR_FORMAT_TOUCH_BIT     0x01
  31 #define TR_FORMAT_STATUS_BYTE   0x40
  32 #define TR_FORMAT_STATUS_MASK   ~TR_FORMAT_TOUCH_BIT
  33
  34 #define TR_LENGTH 5
  35
  36 #define TR_MIN_XC 0
  37 #define TR_MAX_XC 0x1ff
  38 #define TR_MIN_YC 0
  39 #define TR_MAX_YC 0x1ff
  40
  41 /*
  42  * Per-touchscreen data.
  43  */
  44
  45 struct tr {
  46         struct input_dev *dev;
  47         struct serio *serio;
  48         int idx;
  49         unsigned char data[TR_LENGTH];
  50         char phys[32];
  51 };
  52
  53 static irqreturn_t tr_interrupt(struct serio *serio,
  54                 unsigned char data, unsigned int flags)
  55 {
  56         struct tr *tr = serio_get_drvdata(serio);
  57         struct input_dev *dev = tr->dev;
  58
  59         tr->data[tr->idx] = data;
  60
  61         if ((tr->data[0] & TR_FORMAT_STATUS_MASK) == TR_FORMAT_STATUS_BYTE) {
  62                 if (++tr->idx == TR_LENGTH) {
  63                         input_report_abs(dev, ABS_X,
  64                                 (tr->data[1] << 5) | (tr->data[2] >> 1));
  65                         input_report_abs(dev, ABS_Y,
  66                                 (tr->data[3] << 5) | (tr->data[4] >> 1));
  67                         input_report_key(dev, BTN_TOUCH,
  68                                 tr->data[0] & TR_FORMAT_TOUCH_BIT);
  69                         input_sync(dev);
  70                         tr->idx = 0;
  71                 }
  72         }
  73
  74         return IRQ_HANDLED;
  75 }
  76
  77 /*
  78  * tr_disconnect() is the opposite of tr_connect()
  79  */
  80
  81 static void tr_disconnect(struct serio *serio)
  82 {
  83         struct tr *tr = serio_get_drvdata(serio);
  84
  85         input_get_device(tr->dev);
  86         input_unregister_device(tr->dev);
  87         serio_close(serio);
  88         serio_set_drvdata(serio, NULL);
  89         input_put_device(tr->dev);
  90         kfree(tr);
  91 }
  92
  93 /*
  94  * tr_connect() is the routine that is called when someone adds a
  95  * new serio device that supports the Touchright protocol and registers it as
  96  * an input device.
  97  */
  98
  99 static int tr_connect(struct serio *serio, struct serio_driver *drv)
 100 {
 101         struct tr *tr;
 102         struct input_dev *input_dev;
 103         int err;
 104
 105         tr = kzalloc(sizeof(*tr), GFP_KERNEL);
 106         input_dev = input_allocate_device();
 107         if (!tr || !input_dev) {
 108                 err = -ENOMEM;
 109                 goto fail1;
 110         }
 111
 112         tr->serio = serio;
 113         tr->dev = input_dev;
 114         snprintf(tr->phys, sizeof(tr->phys), "%s/input0", serio->phys);
 115
 116         input_dev->name = "Touchright Serial TouchScreen";
 117         input_dev->phys = tr->phys;
 118         input_dev->id.bustype = BUS_RS232;
 119         input_dev->id.vendor = SERIO_TOUCHRIGHT;
 120         input_dev->id.product = 0;
 121         input_dev->id.version = 0x0100;
 122         input_dev->dev.parent = &serio->dev;
 123         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 124         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 125         input_set_abs_params(tr->dev, ABS_X, TR_MIN_XC, TR_MAX_XC, 0, 0);
 126         input_set_abs_params(tr->dev, ABS_Y, TR_MIN_YC, TR_MAX_YC, 0, 0);
 127
 128         serio_set_drvdata(serio, tr);
 129
 130         err = serio_open(serio, drv);
 131         if (err)
 132                 goto fail2;
 133
 134         err = input_register_device(tr->dev);
 135         if (err)
 136                 goto fail3;
 137
 138         return 0;
 139
 140  fail3: serio_close(serio);
 141  fail2: serio_set_drvdata(serio, NULL);
 142  fail1: input_free_device(input_dev);
 143         kfree(tr);
 144         return err;
 145 }
 146
 147 /*
 148  * The serio driver structure.
 149  */
 150
 151 static const struct serio_device_id tr_serio_ids[] = {
 152         {
 153                 .type   = SERIO_RS232,
 154                 .proto  = SERIO_TOUCHRIGHT,
 155                 .id     = SERIO_ANY,
 156                 .extra  = SERIO_ANY,
 157         },
 158         { 0 }
 159 };
 160
 161 MODULE_DEVICE_TABLE(serio, tr_serio_ids);
 162
 163 static struct serio_driver tr_drv = {
 164         .driver         = {
 165                 .name   = "touchright",
 166         },
 167         .description    = DRIVER_DESC,
 168         .id_table       = tr_serio_ids,
 169         .interrupt      = tr_interrupt,
 170         .connect        = tr_connect,
 171         .disconnect     = tr_disconnect,
 172 };
 173
 174 module_serio_driver(tr_drv);