drivers/input/touchscreen/fujitsu_ts.c

   1 /*
   2  * Fujitsu serial touchscreen driver
   3  *
   4  * Copyright (c) Dmitry Torokhov <dtor@mail.ru>
   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
  10  * by the Free Software Foundation.
  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 #include <linux/init.h>
  20
  21 #define DRIVER_DESC     "Fujitsu serial touchscreen driver"
  22
  23 MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
  24 MODULE_DESCRIPTION(DRIVER_DESC);
  25 MODULE_LICENSE("GPL");
  26
  27 #define FUJITSU_LENGTH 5
  28
  29 /*
  30  * Per-touchscreen data.
  31  */
  32 struct fujitsu {
  33         struct input_dev *dev;
  34         struct serio *serio;
  35         int idx;
  36         unsigned char data[FUJITSU_LENGTH];
  37         char phys[32];
  38 };
  39
  40 /*
  41  * Decode serial data (5 bytes per packet)
  42  * First byte
  43  * 1 C 0 0 R S S S
  44  * Where C is 1 while in calibration mode (which we don't use)
  45  * R is 1 when no coordinate corection was done.
  46  * S are button state
  47  */
  48 static irqreturn_t fujitsu_interrupt(struct serio *serio,
  49                                      unsigned char data, unsigned int flags)
  50 {
  51         struct fujitsu *fujitsu = serio_get_drvdata(serio);
  52         struct input_dev *dev = fujitsu->dev;
  53
  54         if (fujitsu->idx == 0) {
  55                 /* resync skip until start of frame */
  56                 if ((data & 0xf0) != 0x80)
  57                         return IRQ_HANDLED;
  58         } else {
  59                 /* resync skip garbage */
  60                 if (data & 0x80) {
  61                         fujitsu->idx = 0;
  62                         return IRQ_HANDLED;
  63                 }
  64         }
  65
  66         fujitsu->data[fujitsu->idx++] = data;
  67         if (fujitsu->idx == FUJITSU_LENGTH) {
  68                 input_report_abs(dev, ABS_X,
  69                                  (fujitsu->data[2] << 7) | fujitsu->data[1]);
  70                 input_report_abs(dev, ABS_Y,
  71                                  (fujitsu->data[4] << 7) | fujitsu->data[3]);
  72                 input_report_key(dev, BTN_TOUCH,
  73                                  (fujitsu->data[0] & 0x03) != 2);
  74                 input_sync(dev);
  75                 fujitsu->idx = 0;
  76         }
  77
  78         return IRQ_HANDLED;
  79 }
  80
  81 /*
  82  * fujitsu_disconnect() is the opposite of fujitsu_connect()
  83  */
  84 static void fujitsu_disconnect(struct serio *serio)
  85 {
  86         struct fujitsu *fujitsu = serio_get_drvdata(serio);
  87
  88         input_get_device(fujitsu->dev);
  89         input_unregister_device(fujitsu->dev);
  90         serio_close(serio);
  91         serio_set_drvdata(serio, NULL);
  92         input_put_device(fujitsu->dev);
  93         kfree(fujitsu);
  94 }
  95
  96 /*
  97  * fujitsu_connect() is the routine that is called when someone adds a
  98  * new serio device that supports the Fujitsu protocol and registers it
  99  * as input device.
 100  */
 101 static int fujitsu_connect(struct serio *serio, struct serio_driver *drv)
 102 {
 103         struct fujitsu *fujitsu;
 104         struct input_dev *input_dev;
 105         int err;
 106
 107         fujitsu = kzalloc(sizeof(struct fujitsu), GFP_KERNEL);
 108         input_dev = input_allocate_device();
 109         if (!fujitsu || !input_dev) {
 110                 err = -ENOMEM;
 111                 goto fail1;
 112         }
 113
 114         fujitsu->serio = serio;
 115         fujitsu->dev = input_dev;
 116         snprintf(fujitsu->phys, sizeof(fujitsu->phys),
 117                  "%s/input0", serio->phys);
 118
 119         input_dev->name = "Fujitsu Serial Touchscreen";
 120         input_dev->phys = fujitsu->phys;
 121         input_dev->id.bustype = BUS_RS232;
 122         input_dev->id.vendor = SERIO_FUJITSU;
 123         input_dev->id.product = 0;
 124         input_dev->id.version = 0x0100;
 125         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 126         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 127
 128         input_set_abs_params(input_dev, ABS_X, 0, 4096, 0, 0);
 129         input_set_abs_params(input_dev, ABS_Y, 0, 4096, 0, 0);
 130         serio_set_drvdata(serio, fujitsu);
 131
 132         err = serio_open(serio, drv);
 133         if (err)
 134                 goto fail2;
 135
 136         err = input_register_device(fujitsu->dev);
 137         if (err)
 138                 goto fail3;
 139
 140         return 0;
 141
 142  fail3:
 143         serio_close(serio);
 144  fail2:
 145         serio_set_drvdata(serio, NULL);
 146  fail1:
 147         input_free_device(input_dev);
 148         kfree(fujitsu);
 149         return err;
 150 }
 151
 152 /*
 153  * The serio driver structure.
 154  */
 155 static struct serio_device_id fujitsu_serio_ids[] = {
 156         {
 157                 .type   = SERIO_RS232,
 158                 .proto  = SERIO_FUJITSU,
 159                 .id     = SERIO_ANY,
 160                 .extra  = SERIO_ANY,
 161         },
 162         { 0 }
 163 };
 164
 165 MODULE_DEVICE_TABLE(serio, fujitsu_serio_ids);
 166
 167 static struct serio_driver fujitsu_drv = {
 168         .driver         = {
 169                 .name   = "fujitsu_ts",
 170         },
 171         .description    = DRIVER_DESC,
 172         .id_table       = fujitsu_serio_ids,
 173         .interrupt      = fujitsu_interrupt,
 174         .connect        = fujitsu_connect,
 175         .disconnect     = fujitsu_disconnect,
 176 };
 177
 178 static int __init fujitsu_init(void)
 179 {
 180         return serio_register_driver(&fujitsu_drv);
 181 }
 182
 183 static void __exit fujitsu_exit(void)
 184 {
 185         serio_unregister_driver(&fujitsu_drv);
 186 }
 187
 188 module_init(fujitsu_init);
 189 module_exit(fujitsu_exit);