path: root/drivers/input/gameport/gameport.c

/*
 * Generic gameport layer
 *
 * Copyright (c) 1999-2002 Vojtech Pavlik
 * Copyright (c) 2005 Dmitry Torokhov
 */

/*
 * 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/stddef.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/gameport.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/sched.h>	/* HZ */
#include <linux/mutex.h>
#include <linux/freezer.h>

/*#include <asm/io.h>*/

MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Generic gameport layer");
MODULE_LICENSE("GPL");

/*
 * gameport_mutex protects entire gameport subsystem and is taken
 * every time gameport port or driver registrered or unregistered.
 */
static DEFINE_MUTEX(gameport_mutex);

static LIST_HEAD(gameport_list);

static struct bus_type gameport_bus;

static void gameport_add_port(struct gameport *gameport);
static void gameport_attach_driver(struct gameport_driver *drv);
static void gameport_reconnect_port(struct gameport *gameport);
static void gameport_disconnect_port(struct gameport *gameport);

#if defined(__i386__)

#include <asm/i8253.h>

#define DELTA(x,y)      ((y)-(x)+((y)<(x)?1193182/HZ:0))
#define GET_TIME(x)     do { x = get_time_pit(); } while (0)

static unsigned int get_time_pit(void)
{
	unsigned long flags;
	unsigned int count;

	spin_lock_irqsave(&i8253_lock, flags);
	outb_p(0x00, 0x43);
	count = inb_p(0x40);
	count |= inb_p(0x40) << 8;
	spin_unlock_irqrestore(&i8253_lock, flags);

	return count;
}

#endif



/*
 * gameport_measure_speed() measures the gameport i/o speed.
 */

static int gameport_measure_speed(struct gameport *gameport)
{
#if defined(__i386__)

	unsigned int i, t, t1, t2, t3, tx;
	unsigned long flags;

	if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
		return 0;

	tx = 1 << 30;

	for(i = 0; i < 50; i++) {
		local_irq_save(flags);
		GET_TIME(t1);
		for (t = 0; t < 50; t++) gameport_read(gameport);
		GET_TIME(t2);
		GET_TIME(t3);
		local_irq_restore(flags);
		udelay(i * 10);
		if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t;
	}

	gameport_close(gameport);
	return 59659 / (tx < 1 ? 1 : tx);

#elif defined (__x86_64__)

	unsigned int i, t;
	unsigned long tx, t1, t2, flags;

	if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
		return 0;

	tx = 1 << 30;

	for(i = 0; i < 50; i++) {
		local_irq_save(flags);
		rdtscl(t1);
		for (t = 0; t < 50; t++) gameport_read(gameport);
		rdtscl(t2);
		local_irq_restore(flags);
		udelay(i * 10);
		if (t2 - t1 < tx) tx = t2 - t1;
	}

	gameport_close(gameport);
	return (cpu_data(raw_smp_processor_id()).loops_per_jiffy *
		(unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx);

#else

	unsigned int j, t = 0;

	if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
		return 0;

	j = jiffies; while (j == jiffies);
	j = jiffies; while (j == jiffies) { t++; gameport_read(gameport); }

	gameport_close(gameport);
	return t * HZ / 1000;

#endif
}

void gameport_start_polling(struct gameport *gameport)
{
	spin_lock(&gameport->timer_lock);

	if (!gameport->poll_cnt++) {
		BUG_ON(!gameport->poll_handler);
		BUG_ON(!gameport->poll_interval);
		mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
	}

	spin_unlock(&gameport->timer_lock);
}
EXPORT_SYMBOL(gameport_start_polling);

void gameport_stop_polling(struct gameport *gameport)
{
	spin_lock(&gameport->timer_lock);

	if (!--gameport->poll_cnt)
		del_timer(&gameport->poll_timer);

	spin_unlock(&gameport->timer_lock);
}
EXPORT_SYMBOL(gameport_stop_polling);

static void gameport_run_poll_handler(unsigned long d)
{
	struct gameport *gameport = (struct gameport *)d;

	gameport->poll_handler(gameport);
	if (gameport->poll_cnt)
		mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
}

/*
 * Basic gameport -> driver core mappings
 */

static int gameport_bind_driver(struct gameport *gameport, struct gameport_driver *drv)
{
	int error;

	gameport->dev.driver = &drv->driver;
	if (drv->connect(gameport, drv))