LXR linux/drivers/input/touchscreen/fujitsu

   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
  23MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
  24MODULE_DESCRIPTION(DRIVER_DESC);
  25MODULE_LICENSE("GPL");
  26
  27#define FUJITSU_LENGTH 5
  28
  29/*
  30 * Per-touchscreen data.
  31 */
  32struct 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 */
  48static 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 */
  84static 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 */
 101static 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 */
 155static 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
 165MODULE_DEVICE_TABLE(serio, fujitsu_serio_ids);
 166
 167static 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
 178module_serio_driver(fujitsu_drv);
 179