text: /*
   *  PC Speaker beeper driver for Linux
   *
   *  Copyright (c) 2002 Vojtech Pavlik
   *  Copyright (c) 1992 Orest Zborowski
   *
   */
  
  /*
   * 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
   */
  
  #include <linux/init.h>
  #include <linux/input.h>
  #include <asm/io.h>
  #include "pcsp.h"
  
  static void pcspkr_do_sound(unsigned int count)
  {
  	unsigned long flags;
  
  	raw_spin_lock_irqsave(&i8253_lock, flags);
  
  	if (count) {
  		/* set command for counter 2, 2 byte write */
  		outb_p(0xB6, 0x43);
  		/* select desired HZ */
  		outb_p(count & 0xff, 0x42);
  		outb((count >> 8) & 0xff, 0x42);
  		/* enable counter 2 */
  		outb_p(inb_p(0x61) | 3, 0x61);
  	} else {
  		/* disable counter 2 */
  		outb(inb_p(0x61) & 0xFC, 0x61);
  	}
  
  	raw_spin_unlock_irqrestore(&i8253_lock, flags);
  }
  
  void pcspkr_stop_sound(void)
  {
  	pcspkr_do_sound(0);
  }
  
  static int pcspkr_input_event(struct input_dev *dev, unsigned int type,
  			      unsigned int code, int value)
  {
  	unsigned int count = 0;
  
  	if (atomic_read(&pcsp_chip.timer_active) || !pcsp_chip.pcspkr)
  		return 0;
  
  	switch (type) {
  	case EV_SND:
  		switch (code) {
  		case SND_BELL:
  			if (value)
  				value = 1000;
  		case SND_TONE:
  			break;
  		default:
  			return -1;
  		}
  		break;
  
  	default:
  		return -1;
  	}
  
  	if (value > 20 && value < 32767)
  		count = PIT_TICK_RATE / value;
  
  	pcspkr_do_sound(count);
  
  	return 0;
  }
  
  int __devinit pcspkr_input_init(struct input_dev **rdev, struct device *dev)
  {
  	int err;
  
  	struct input_dev *input_dev = input_allocate_device();
  	if (!input_dev)
  		return -ENOMEM;
  
  	input_dev->name = "PC Speaker";
  	input_dev->phys = "isa0061/input0";
  	input_dev->id.bustype = BUS_ISA;
  	input_dev->id.vendor = 0x001f;
  	input_dev->id.product = 0x0001;
  	input_dev->id.version = 0x0100;
  	input_dev->dev.parent = dev;
  
  	input_dev->evbit[0] = BIT(EV_SND);
  	input_dev->sndbit[0] = BIT(SND_BELL) | BIT(SND_TONE);
  	input_dev->event = pcspkr_input_event;
  
  	err = input_register_device(input_dev);
  	if (err) {
  		input_free_device(input_dev);
  		return err;
  	}
  
  	*rdev = input_dev;
  	return 0;
  }
  
  int pcspkr_input_remove(struct input_dev *dev)
  {
  	pcspkr_stop_sound();
  	input_unregister_device(dev);	/* this also does kfree() */
  
  	return 0;
  }
  