gunze.c

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/*
 *  Copyright (c) 2000-2001 Vojtech Pavlik
 */

/*
 * Gunze AHL-51S touchscreen driver for Linux
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <[email protected]>, or by paper mail:
 * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
 */

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/init.h>

#define DRIVER_DESC "Gunze AHL-51S touchscreen driver"

MODULE_AUTHOR("Vojtech Pavlik <[email protected]>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

/*
 * Definitions & global arrays.
 */

#define GUNZE_MAX_LENGTH    10

/*
 * Per-touchscreen data.
 */

struct gunze {
    struct input_dev *dev;
    struct serio *serio;
    int idx;
    unsigned char data[GUNZE_MAX_LENGTH];
    char phys[32];
};

static void gunze_process_packet(struct gunze* gunze)
{
    struct input_dev *dev = gunze->dev;

    if (gunze->idx != GUNZE_MAX_LENGTH || gunze->data[5] != ',' ||
        (gunze->data[0] != 'T' && gunze->data[0] != 'R')) {
        printk(KERN_WARNING "gunze.c: bad packet: >%.*s<\n", GUNZE_MAX_LENGTH, gunze->data);
        return;
    }

    input_report_abs(dev, ABS_X, simple_strtoul(gunze->data + 1, NULL, 10));
    input_report_abs(dev, ABS_Y, 1024 - simple_strtoul(gunze->data + 6, NULL, 10));
    input_report_key(dev, BTN_TOUCH, gunze->data[0] == 'T');
    input_sync(dev);
}

static irqreturn_t gunze_interrupt(struct serio *serio,
        unsigned char data, unsigned int flags)
{
    struct gunze* gunze = serio_get_drvdata(serio);

    if (data == '\r') {
        gunze_process_packet(gunze);
        gunze->idx = 0;
    } else {
        if (gunze->idx < GUNZE_MAX_LENGTH)
            gunze->data[gunze->idx++] = data;
    }
    return IRQ_HANDLED;
}

/*
 * gunze_disconnect() is the opposite of gunze_connect()
 */

static void gunze_disconnect(struct serio *serio)
{
    struct gunze *gunze = serio_get_drvdata(serio);

    input_get_device(gunze->dev);
    input_unregister_device(gunze->dev);
    serio_close(serio);
    serio_set_drvdata(serio, NULL);
    input_put_device(gunze->dev);
    kfree(gunze);
}

/*
 * gunze_connect() is the routine that is called when someone adds a
 * new serio device that supports Gunze protocol and registers it as
 * an input device.
 */

static int gunze_connect(struct serio *serio, struct serio_driver *drv)
{
    struct gunze *gunze;
    struct input_dev *input_dev;
    int err;

    gunze = kzalloc(sizeof(struct gunze), GFP_KERNEL);
    input_dev = input_allocate_device();
    if (!gunze || !input_dev) {
        err = -ENOMEM;
        goto fail1;
    }

    gunze->serio = serio;
    gunze->dev = input_dev;
    snprintf(gunze->phys, sizeof(serio->phys), "%s/input0", serio->phys);

    input_dev->name = "Gunze AHL-51S TouchScreen";
    input_dev->phys = gunze->phys;
    input_dev->id.bustype = BUS_RS232;
    input_dev->id.vendor = SERIO_GUNZE;
    input_dev->id.product = 0x0051;
    input_dev->id.version = 0x0100;
    input_dev->dev.parent = &serio->dev;
    input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
    input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
    input_set_abs_params(input_dev, ABS_X, 24, 1000, 0, 0);
    input_set_abs_params(input_dev, ABS_Y, 24, 1000, 0, 0);

    serio_set_drvdata(serio, gunze);

    err = serio_open(serio, drv);
    if (err)
        goto fail2;

    err = input_register_device(gunze->dev);
    if (err)
        goto fail3;

    return 0;

 fail3: serio_close(serio);
 fail2: serio_set_drvdata(serio, NULL);
 fail1: input_free_device(input_dev);
    kfree(gunze);
    return err;
}

/*
 * The serio driver structure.
 */

static struct serio_device_id gunze_serio_ids[] = {
    {
        .type   = SERIO_RS232,
        .proto  = SERIO_GUNZE,
        .id = SERIO_ANY,
        .extra  = SERIO_ANY,
    },
    { 0 }
};

MODULE_DEVICE_TABLE(serio, gunze_serio_ids);

static struct serio_driver gunze_drv = {
    .driver     = {
        .name   = "gunze",
    },
    .description    = DRIVER_DESC,
    .id_table   = gunze_serio_ids,
    .interrupt  = gunze_interrupt,
    .connect    = gunze_connect,
    .disconnect = gunze_disconnect,
};

module_serio_driver(gunze_drv);