pc110pad.c

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/*
 *  Copyright (c) 2000-2001 Vojtech Pavlik
 *
 *  Based on the work of:
 *  Alan Cox    Robin O'Leary
 */

/*
 * IBM PC110 touchpad 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/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/input.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/delay.h>

#include <asm/io.h>
#include <asm/irq.h>

MODULE_AUTHOR("Vojtech Pavlik <[email protected]>");
MODULE_DESCRIPTION("IBM PC110 touchpad driver");
MODULE_LICENSE("GPL");

#define PC110PAD_OFF    0x30
#define PC110PAD_ON 0x38

static int pc110pad_irq = 10;
static int pc110pad_io = 0x15e0;

static struct input_dev *pc110pad_dev;
static int pc110pad_data[3];
static int pc110pad_count;

static irqreturn_t pc110pad_interrupt(int irq, void *ptr)
{
    int value     = inb_p(pc110pad_io);
    int handshake = inb_p(pc110pad_io + 2);

    outb(handshake |  1, pc110pad_io + 2);
    udelay(2);
    outb(handshake & ~1, pc110pad_io + 2);
    udelay(2);
    inb_p(0x64);

    pc110pad_data[pc110pad_count++] = value;

    if (pc110pad_count < 3)
        return IRQ_HANDLED;

    input_report_key(pc110pad_dev, BTN_TOUCH,
        pc110pad_data[0] & 0x01);
    input_report_abs(pc110pad_dev, ABS_X,
        pc110pad_data[1] | ((pc110pad_data[0] << 3) & 0x80) | ((pc110pad_data[0] << 1) & 0x100));
    input_report_abs(pc110pad_dev, ABS_Y,
        pc110pad_data[2] | ((pc110pad_data[0] << 4) & 0x80));
    input_sync(pc110pad_dev);

    pc110pad_count = 0;
    return IRQ_HANDLED;
}

static void pc110pad_close(struct input_dev *dev)
{
    outb(PC110PAD_OFF, pc110pad_io + 2);
}

static int pc110pad_open(struct input_dev *dev)
{
    pc110pad_interrupt(0, NULL);
    pc110pad_interrupt(0, NULL);
    pc110pad_interrupt(0, NULL);
    outb(PC110PAD_ON, pc110pad_io + 2);
    pc110pad_count = 0;

    return 0;
}

/*
 * We try to avoid enabling the hardware if it's not
 * there, but we don't know how to test. But we do know
 * that the PC110 is not a PCI system. So if we find any
 * PCI devices in the machine, we don't have a PC110.
 */
static int __init pc110pad_init(void)
{
    int err;

    if (!no_pci_devices())
        return -ENODEV;

    if (!request_region(pc110pad_io, 4, "pc110pad")) {
        printk(KERN_ERR "pc110pad: I/O area %#x-%#x in use.\n",
                pc110pad_io, pc110pad_io + 4);
        return -EBUSY;
    }

    outb(PC110PAD_OFF, pc110pad_io + 2);

    if (request_irq(pc110pad_irq, pc110pad_interrupt, 0, "pc110pad", NULL)) {
        printk(KERN_ERR "pc110pad: Unable to get irq %d.\n", pc110pad_irq);
        err = -EBUSY;
        goto err_release_region;
    }

    pc110pad_dev = input_allocate_device();
    if (!pc110pad_dev) {
        printk(KERN_ERR "pc110pad: Not enough memory.\n");
        err = -ENOMEM;
        goto err_free_irq;
    }

    pc110pad_dev->name = "IBM PC110 TouchPad";
    pc110pad_dev->phys = "isa15e0/input0";
    pc110pad_dev->id.bustype = BUS_ISA;
    pc110pad_dev->id.vendor = 0x0003;
    pc110pad_dev->id.product = 0x0001;
    pc110pad_dev->id.version = 0x0100;

    pc110pad_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
    pc110pad_dev->absbit[0] = BIT_MASK(ABS_X) | BIT_MASK(ABS_Y);
    pc110pad_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

    input_abs_set_max(pc110pad_dev, ABS_X, 0x1ff);
    input_abs_set_max(pc110pad_dev, ABS_Y, 0x0ff);

    pc110pad_dev->open = pc110pad_open;
    pc110pad_dev->close = pc110pad_close;

    err = input_register_device(pc110pad_dev);
    if (err)
        goto err_free_dev;

    return 0;

 err_free_dev:
    input_free_device(pc110pad_dev);
 err_free_irq:
    free_irq(pc110pad_irq, NULL);
 err_release_region:
    release_region(pc110pad_io, 4);

    return err;
}

static void __exit pc110pad_exit(void)
{
    outb(PC110PAD_OFF, pc110pad_io + 2);
    free_irq(pc110pad_irq, NULL);
    input_unregister_device(pc110pad_dev);
    release_region(pc110pad_io, 4);
}

module_init(pc110pad_init);
module_exit(pc110pad_exit);