// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Amiga mouse driver for Linux/m68k
 *
 *  Copyright (c) 2000-2002 Vojtech Pavlik
 *
 *  Based on the work of:
 *      Michael Rausch          James Banks
 *      Matther Dillon          David Giller
 *      Nathan Laredo           Linus Torvalds
 *      Johan Myreen            Jes Sorensen
 *      Russell King
 */


#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>

#include <asm/irq.h>
#include <asm/setup.h>
#include <linux/uaccess.h>
#include <asm/amigahw.h>
#include <asm/amigaints.h>

MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Amiga mouse driver");
MODULE_LICENSE("GPL");

static int amimouse_lastx, amimouse_lasty;

static irqreturn_t amimouse_interrupt(int irq, void *data)
{
        struct input_dev *dev = data;
        unsigned short joy0dat, potgor;
        int nx, ny, dx, dy;

        joy0dat = amiga_custom.joy0dat;

        nx = joy0dat & 0xff;
        ny = joy0dat >> 8;

        dx = nx - amimouse_lastx;
        dy = ny - amimouse_lasty;

        if (dx < -127) dx = (256 + nx) - amimouse_lastx;
        if (dx >  127) dx = (nx - 256) - amimouse_lastx;
        if (dy < -127) dy = (256 + ny) - amimouse_lasty;
        if (dy >  127) dy = (ny - 256) - amimouse_lasty;

        amimouse_lastx = nx;
        amimouse_lasty = ny;

        potgor = amiga_custom.potgor;

        input_report_rel(dev, REL_X, dx);
        input_report_rel(dev, REL_Y, dy);

        input_report_key(dev, BTN_LEFT,   ciaa.pra & 0x40);
        input_report_key(dev, BTN_MIDDLE, potgor & 0x0100);
        input_report_key(dev, BTN_RIGHT,  potgor & 0x0400);

        input_sync(dev);

        return IRQ_HANDLED;
}

static int amimouse_open(struct input_dev *dev)
{
        unsigned short joy0dat;
        int error;

        joy0dat = amiga_custom.joy0dat;

        amimouse_lastx = joy0dat & 0xff;
        amimouse_lasty = joy0dat >> 8;

        error = request_irq(IRQ_AMIGA_VERTB, amimouse_interrupt, 0, "amimouse",
                            dev);
        if (error)
                dev_err(&dev->dev, "Can't allocate irq %d\n", IRQ_AMIGA_VERTB);

        return error;
}

static void amimouse_close(struct input_dev *dev)
{
        free_irq(IRQ_AMIGA_VERTB, dev);
}

static int __init amimouse_probe(struct platform_device *pdev)
{
        int err;
        struct input_dev *dev;

        dev = input_allocate_device();
        if (!dev)
                return -ENOMEM;

        dev->name = pdev->name;
        dev->phys = "amimouse/input0";
        dev->id.bustype = BUS_AMIGA;
        dev->id.vendor = 0x0001;
        dev->id.product = 0x0002;
        dev->id.version = 0x0100;

        dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
        dev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y);
        dev->keybit[BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) |
                BIT_MASK(BTN_MIDDLE) | BIT_MASK(BTN_RIGHT);
        dev->open = amimouse_open;
        dev->close = amimouse_close;
        dev->dev.parent = &pdev->dev;

        err = input_register_device(dev);
        if (err) {
                input_free_device(dev);
                return err;
        }

        platform_set_drvdata(pdev, dev);

        return 0;
}

static void __exit amimouse_remove(struct platform_device *pdev)
{
        struct input_dev *dev = platform_get_drvdata(pdev);

        input_unregister_device(dev);
}

/*
 * amimouse_remove() lives in .exit.text. For drivers registered via
 * module_platform_driver_probe() this is ok because they cannot get unbound at
 * runtime. So mark the driver struct with __refdata to prevent modpost
 * triggering a section mismatch warning.
 */
static struct platform_driver amimouse_driver __refdata = {
        .remove = __exit_p(amimouse_remove),
        .driver   = {
                .name   = "amiga-mouse",
        },
};

module_platform_driver_probe(amimouse_driver, amimouse_probe);

MODULE_ALIAS("platform:amiga-mouse");