text: /*
   *  Acorn RiscPC mouse driver for Linux/ARM
   *
   *  Copyright (c) 2000-2002 Vojtech Pavlik
   *  Copyright (C) 1996-2002 Russell King
   *
   */
  
  /*
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published by
   * the Free Software Foundation.
   *
   * 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 <asm/hardware.h>
  #include <asm/irq.h>
  #include <asm/io.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(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(EV_KEY) | BIT(EV_REL);
  	rpcmouse_dev->keybit[LONG(BTN_LEFT)] = BIT(BTN_LEFT) | BIT(BTN_MIDDLE) | BIT(BTN_RIGHT);
  	rpcmouse_dev->relbit[0]	= BIT(REL_X) | BIT(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);
  