LXR linux/drivers/input/touchscreen/fujitsu

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Fujitsu serial touchscreen driver
   4 *
   5 * Copyright (c) Dmitry Torokhov <dtor@mail.ru>
   6 */
   7
   8
   9#include <linux/errno.h>
  10#include <linux/kernel.h>
  11#include <linux/module.h>
  12#include <linux/slab.h>
  13#include <linux/input.h>
  14#include <linux/serio.h>
  15
  16#define DRIVER_DESC     "Fujitsu serial touchscreen driver"
  17
  18MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
  19MODULE_DESCRIPTION(DRIVER_DESC);
  20MODULE_LICENSE("GPL");
  21
  22#define FUJITSU_LENGTH 5
  23
  24/*
  25 * Per-touchscreen data.
  26 */
  27struct fujitsu {
  28        struct input_dev *dev;
  29        struct serio *serio;
  30        int idx;
  31        unsigned char data[FUJITSU_LENGTH];
  32        char phys[32];
  33};
  34
  35/*
  36 * Decode serial data (5 bytes per packet)
  37 * First byte
  38 * 1 C 0 0 R S S S
  39 * Where C is 1 while in calibration mode (which we don't use)
  40 * R is 1 when no coordinate corection was done.
  41 * S are button state
  42 */
  43static irqreturn_t fujitsu_interrupt(struct serio *serio,
  44                                     unsigned char data, unsigned int flags)
  45{
  46        struct fujitsu *fujitsu = serio_get_drvdata(serio);
  47        struct input_dev *dev = fujitsu->dev;
  48
  49        if (fujitsu->idx == 0) {
  50                /* resync skip until start of frame */
  51                if ((data & 0xf0) != 0x80)
  52                        return IRQ_HANDLED;
  53        } else {
  54                /* resync skip garbage */
  55                if (data & 0x80) {
  56                        fujitsu->idx = 0;
  57                        return IRQ_HANDLED;
  58                }
  59        }
  60
  61        fujitsu->data[fujitsu->idx++] = data;
  62        if (fujitsu->idx == FUJITSU_LENGTH) {
  63                input_report_abs(dev, ABS_X,
  64                                 (fujitsu->data[2] << 7) | fujitsu->data[1]);
  65                input_report_abs(dev, ABS_Y,
  66                                 (fujitsu->data[4] << 7) | fujitsu->data[3]);
  67                input_report_key(dev, BTN_TOUCH,
  68                                 (fujitsu->data[0] & 0x03) != 2);
  69                input_sync(dev);
  70                fujitsu->idx = 0;
  71        }
  72
  73        return IRQ_HANDLED;
  74}
  75
  76/*
  77 * fujitsu_disconnect() is the opposite of fujitsu_connect()
  78 */
  79static void fujitsu_disconnect(struct serio *serio)
  80{
  81        struct fujitsu *fujitsu = serio_get_drvdata(serio);
  82
  83        input_get_device(fujitsu->dev);
  84        input_unregister_device(fujitsu->dev);
  85        serio_close(serio);
  86        serio_set_drvdata(serio, NULL);
  87        input_put_device(fujitsu->dev);
  88        kfree(fujitsu);
  89}
  90
  91/*
  92 * fujitsu_connect() is the routine that is called when someone adds a
  93 * new serio device that supports the Fujitsu protocol and registers it
  94 * as input device.
  95 */
  96static int fujitsu_connect(struct serio *serio, struct serio_driver *drv)
  97{
  98        struct fujitsu *fujitsu;
  99        struct input_dev *input_dev;
 100        int err;
 101
 102        fujitsu = kzalloc(sizeof(struct fujitsu), GFP_KERNEL);
 103        input_dev = input_allocate_device();
 104        if (!fujitsu || !input_dev) {
 105                err = -ENOMEM;
 106                goto fail1;
 107        }
 108
 109        fujitsu->serio = serio;
 110        fujitsu->dev = input_dev;
 111        snprintf(fujitsu->phys, sizeof(fujitsu->phys),
 112                 "%s/input0", serio->phys);
 113
 114        input_dev->name = "Fujitsu Serial Touchscreen";
 115        input_dev->phys = fujitsu->phys;
 116        input_dev->id.bustype = BUS_RS232;
 117        input_dev->id.vendor = SERIO_FUJITSU;
 118        input_dev->id.product = 0;
 119        input_dev->id.version = 0x0100;
 120        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 121        input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 122
 123        input_set_abs_params(input_dev, ABS_X, 0, 4096, 0, 0);
 124        input_set_abs_params(input_dev, ABS_Y, 0, 4096, 0, 0);
 125        serio_set_drvdata(serio, fujitsu);
 126
 127        err = serio_open(serio, drv);
 128        if (err)
 129                goto fail2;
 130
 131        err = input_register_device(fujitsu->dev);
 132        if (err)
 133                goto fail3;
 134
 135        return 0;
 136
 137 fail3:
 138        serio_close(serio);
 139 fail2:
 140        serio_set_drvdata(serio, NULL);
 141 fail1:
 142        input_free_device(input_dev);
 143        kfree(fujitsu);
 144        return err;
 145}
 146
 147/*
 148 * The serio driver structure.
 149 */
 150static const struct serio_device_id fujitsu_serio_ids[] = {
 151        {
 152                .type   = SERIO_RS232,
 153                .proto  = SERIO_FUJITSU,
 154                .id     = SERIO_ANY,
 155                .extra  = SERIO_ANY,
 156        },
 157        { 0 }
 158};
 159
 160MODULE_DEVICE_TABLE(serio, fujitsu_serio_ids);
 161
 162static struct serio_driver fujitsu_drv = {
 163        .driver         = {
 164                .name   = "fujitsu_ts",
 165        },
 166        .description    = DRIVER_DESC,
 167        .id_table       = fujitsu_serio_ids,
 168        .interrupt      = fujitsu_interrupt,
 169        .connect        = fujitsu_connect,
 170        .disconnect     = fujitsu_disconnect,
 171};
 172
 173module_serio_driver(fujitsu_drv);
 174