// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Acorn RiscPC mouse driver for Linux/ARM
 *
 *  Copyright (c) 2000-2002 Vojtech Pavlik
 *  Copyright (C) 1996-2002 Russell King
 */

/*
 *
 * This handles the Acorn RiscPCs mouse.  We basically have a couple of
 * hardware registers that track the sensor count for the X-Y movement and
 * another register holding the button state.  On every VSYNC interrupt we read
 * the complete state and then work out if something has changed.
 */

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

#include <mach/hardware.h>
#include <asm/irq.h>
#include <asm/hardware/iomd.h>

MODULE_AUTHOR("Vojtech Pavlik, Russell King");
MODULE_DESCRIPTION("Acorn RiscPC mouse driver");
MODULE_LICENSE("GPL");

static short rpcmouse_lastx, rpcmouse_lasty;
static struct input_dev *rpcmouse_dev;

static irqreturn_t rpcmouse_irq(int irq, void *dev_id)
{
        struct input_dev *dev = dev_id;
        short x, y, dx, dy, b;

        x = (short) iomd_readl(IOMD_MOUSEX);
        y = (short) iomd_readl(IOMD_MOUSEY);
        b = (short) (__raw_readl(IOMEM(0xe0310000)) ^ 0x70);

        dx = x - rpcmouse_lastx;
        dy = y - rpcmouse_lasty;

        rpcmouse_lastx = x;
        rpcmouse_lasty = y;

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

        input_report_key(dev, BTN_LEFT,   b & 0x40);
        input_report_key(dev, BTN_MIDDLE, b & 0x20);
        input_report_key(dev, BTN_RIGHT,  b & 0x10);

        input_sync(dev);

        return IRQ_HANDLED;
}


static int __init rpcmouse_init(void)
{
        int err;

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

        rpcmouse_dev->name = "Acorn RiscPC Mouse";
        rpcmouse_dev->phys = "rpcmouse/input0";
        rpcmouse_dev->id.bustype = BUS_HOST;
        rpcmouse_dev->id.vendor  = 0x0005;
        rpcmouse_dev->id.product = 0x0001;
        rpcmouse_dev->id.version = 0x0100;

        rpcmouse_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
        rpcmouse_dev->keybit[BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) |
                BIT_MASK(BTN_MIDDLE) | BIT_MASK(BTN_RIGHT);
        rpcmouse_dev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y);

        rpcmouse_lastx = (short) iomd_readl(IOMD_MOUSEX);
        rpcmouse_lasty = (short) iomd_readl(IOMD_MOUSEY);

        if (request_irq(IRQ_VSYNCPULSE, rpcmouse_irq, IRQF_SHARED, "rpcmouse", rpcmouse_dev)) {
                printk(KERN_ERR "rpcmouse: unable to allocate VSYNC interrupt\n");
                err = -EBUSY;
                goto err_free_dev;
        }

        err = input_register_device(rpcmouse_dev);
        if (err)
                goto err_free_irq;

        return 0;

 err_free_irq:
        free_irq(IRQ_VSYNCPULSE, rpcmouse_dev);
 err_free_dev:
        input_free_device(rpcmouse_dev);

        return err;
}

static void __exit rpcmouse_exit(void)
{
        free_irq(IRQ_VSYNCPULSE, rpcmouse_dev);
        input_unregister_device(rpcmouse_dev);
}

module_init(rpcmouse_init);
module_exit(rpcmouse_exit);