// SPDX-License-Identifier: GPL-2.0-only
/*
 *      SEGA Dreamcast mouse driver
 *      Based on drivers/usb/usbmouse.c
 *
 *      Copyright (c) Yaegashi Takeshi, 2001
 *      Copyright (c) Adrian McMenamin, 2008 - 2009
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/maple.h>

MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
MODULE_DESCRIPTION("SEGA Dreamcast mouse driver");
MODULE_LICENSE("GPL");

struct dc_mouse {
        struct input_dev *dev;
        struct maple_device *mdev;
};

static void dc_mouse_callback(struct mapleq *mq)
{
        int buttons, relx, rely, relz;
        struct maple_device *mapledev = mq->dev;
        struct dc_mouse *mse = maple_get_drvdata(mapledev);
        struct input_dev *dev = mse->dev;
        unsigned char *res = mq->recvbuf->buf;

        buttons = ~res[8];
        relx = *(unsigned short *)(res + 12) - 512;
        rely = *(unsigned short *)(res + 14) - 512;
        relz = *(unsigned short *)(res + 16) - 512;

        input_report_key(dev, BTN_LEFT,   buttons & 4);
        input_report_key(dev, BTN_MIDDLE, buttons & 9);
        input_report_key(dev, BTN_RIGHT,  buttons & 2);
        input_report_rel(dev, REL_X,      relx);
        input_report_rel(dev, REL_Y,      rely);
        input_report_rel(dev, REL_WHEEL,  relz);
        input_sync(dev);
}

static int dc_mouse_open(struct input_dev *dev)
{
        struct dc_mouse *mse = maple_get_drvdata(to_maple_dev(&dev->dev));

        maple_getcond_callback(mse->mdev, dc_mouse_callback, HZ/50,
                MAPLE_FUNC_MOUSE);

        return 0;
}

static void dc_mouse_close(struct input_dev *dev)
{
        struct dc_mouse *mse = maple_get_drvdata(to_maple_dev(&dev->dev));

        maple_getcond_callback(mse->mdev, dc_mouse_callback, 0,
                MAPLE_FUNC_MOUSE);
}

/* allow the mouse to be used */
static int probe_maple_mouse(struct device *dev)
{
        struct maple_device *mdev = to_maple_dev(dev);
        struct maple_driver *mdrv = to_maple_driver(dev->driver);
        int error;
        struct input_dev *input_dev;
        struct dc_mouse *mse;

        mse = kzalloc_obj(*mse);
        if (!mse) {
                error = -ENOMEM;
                goto fail;
        }

        input_dev = input_allocate_device();
        if (!input_dev) {
                error = -ENOMEM;
                goto fail_nomem;
        }

        mse->dev = input_dev;
        mse->mdev = mdev;

        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
        input_dev->keybit[BIT_WORD(BTN_MOUSE)] = BIT_MASK(BTN_LEFT) |
                BIT_MASK(BTN_RIGHT) | BIT_MASK(BTN_MIDDLE);
        input_dev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y) |
                BIT_MASK(REL_WHEEL);
        input_dev->open = dc_mouse_open;
        input_dev->close = dc_mouse_close;
        input_dev->name = mdev->product_name;
        input_dev->id.bustype = BUS_HOST;
        error = input_register_device(input_dev);
        if (error)
                goto fail_register;

        mdev->driver = mdrv;
        maple_set_drvdata(mdev, mse);

        return error;

fail_register:
        input_free_device(input_dev);
fail_nomem:
        kfree(mse);
fail:
        return error;
}

static int remove_maple_mouse(struct device *dev)
{
        struct maple_device *mdev = to_maple_dev(dev);
        struct dc_mouse *mse = maple_get_drvdata(mdev);

        mdev->callback = NULL;
        input_unregister_device(mse->dev);
        maple_set_drvdata(mdev, NULL);
        kfree(mse);

        return 0;
}

static struct maple_driver dc_mouse_driver = {
        .function =     MAPLE_FUNC_MOUSE,
        .drv = {
                .name = "Dreamcast_mouse",
                .probe = probe_maple_mouse,
                .remove = remove_maple_mouse,
        },
};

static int __init dc_mouse_init(void)
{
        return maple_driver_register(&dc_mouse_driver);
}

static void __exit dc_mouse_exit(void)
{
        maple_driver_unregister(&dc_mouse_driver);
}

module_init(dc_mouse_init);
module_exit(dc_mouse_exit);