blob: b2a68ab2afedeb6797e52564503b1df34eed1124 [file] [log] [blame]
/*
* Generic gameport layer
*
* Copyright (c) 1999-2002 Vojtech Pavlik
*/
/*
* 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 <asm/io.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/gameport.h>
#include <linux/slab.h>
#include <linux/stddef.h>
#include <linux/delay.h>
MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Generic gameport layer");
MODULE_LICENSE("GPL");
EXPORT_SYMBOL(gameport_register_port);
EXPORT_SYMBOL(gameport_unregister_port);
EXPORT_SYMBOL(gameport_register_device);
EXPORT_SYMBOL(gameport_unregister_device);
EXPORT_SYMBOL(gameport_open);
EXPORT_SYMBOL(gameport_close);
EXPORT_SYMBOL(gameport_rescan);
EXPORT_SYMBOL(gameport_cooked_read);
static LIST_HEAD(gameport_list);
static LIST_HEAD(gameport_dev_list);
#ifdef __i386__
#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)
{
extern spinlock_t i8253_lock;
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)
{
#ifdef __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);
#else
unsigned int j, t = 0;
j = jiffies; while (j == jiffies);
j = jiffies; while (j == jiffies) { t++; gameport_read(gameport); }
gameport_close(gameport);
return t * HZ / 1000;
#endif
}
static void gameport_find_dev(struct gameport *gameport)
{
struct gameport_dev *dev;
list_for_each_entry(dev, &gameport_dev_list, node) {
if (gameport->dev)
break;
if (dev->connect)
dev->connect(gameport, dev);
}
}
void gameport_rescan(struct gameport *gameport)
{
gameport_close(gameport);
gameport_find_dev(gameport);
}
void gameport_register_port(struct gameport *gameport)
{
list_add_tail(&gameport->node, &gameport_list);
gameport->speed = gameport_measure_speed(gameport);
gameport_find_dev(gameport);
}
void gameport_unregister_port(struct gameport *gameport)
{
list_del_init(&gameport->node);
if (gameport->dev && gameport->dev->disconnect)
gameport->dev->disconnect(gameport);
}
void gameport_register_device(struct gameport_dev *dev)
{
struct gameport *gameport;
list_add_tail(&dev->node, &gameport_dev_list);
list_for_each_entry(gameport, &gameport_list, node)
if (!gameport->dev && dev->connect)
dev->connect(gameport, dev);
}
void gameport_unregister_device(struct gameport_dev *dev)
{
struct gameport *gameport;
list_del_init(&dev->node);
list_for_each_entry(gameport, &gameport_list, node) {
if (gameport->dev == dev && dev->disconnect)
dev->disconnect(gameport);
gameport_find_dev(gameport);
}
}
int gameport_open(struct gameport *gameport, struct gameport_dev *dev, int mode)
{
if (gameport->open) {
if (gameport->open(gameport, mode))
return -1;
} else {
if (mode != GAMEPORT_MODE_RAW)
return -1;
}
if (gameport->dev)
return -1;
gameport->dev = dev;
return 0;
}
void gameport_close(struct gameport *gameport)
{
gameport->dev = NULL;
if (gameport->close)
gameport->close(gameport);
}