/*
   *  Copyright (c) 1998-2001 Vojtech Pavlik
   */
  
  /*
   * PDPI Lightning 4 gamecard driver for Linux.
   */
  
  /*
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   *
   * Should you need to contact me, the author, you can do so either by
   * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
   * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
   */
  
  #include <asm/io.h>
  #include <linux/delay.h>
  #include <linux/errno.h>
  #include <linux/ioport.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/gameport.h>
  
  #define L4_PORT			0x201
  #define L4_SELECT_ANALOG	0xa4
  #define L4_SELECT_DIGITAL	0xa5
  #define L4_SELECT_SECONDARY	0xa6
  #define L4_CMD_ID		0x80
  #define L4_CMD_GETCAL		0x92
  #define L4_CMD_SETCAL		0x93
  #define L4_ID			0x04
  #define L4_BUSY			0x01
  #define L4_TIMEOUT		80	/* 80 us */
  
  MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  MODULE_DESCRIPTION("PDPI Lightning 4 gamecard driver");
  MODULE_LICENSE("GPL");
  
  struct l4 {
  	struct gameport *gameport;
  	unsigned char port;
  };
  
  static struct l4 l4_ports[8];
  
  /*
   * l4_wait_ready() waits for the L4 to become ready.
   */
  
  static int l4_wait_ready(void)
  {
  	unsigned int t = L4_TIMEOUT;
  
  	while ((inb(L4_PORT) & L4_BUSY) && t > 0) t--;
  	return -(t <= 0);
  }
  
  /*
   * l4_cooked_read() reads data from the Lightning 4.
   */
  
  static int l4_cooked_read(struct gameport *gameport, int *axes, int *buttons)
  {
  	struct l4 *l4 = gameport->port_data;
  	unsigned char status;
  	int i, result = -1;
  
  	outb(L4_SELECT_ANALOG, L4_PORT);
  	outb(L4_SELECT_DIGITAL + (l4->port >> 2), L4_PORT);
  
  	if (inb(L4_PORT) & L4_BUSY) goto fail;
  	outb(l4->port & 3, L4_PORT);
  
  	if (l4_wait_ready()) goto fail;
  	status = inb(L4_PORT);
  
  	for (i = 0; i < 4; i++)
  		if (status & (1 << i)) {
  			if (l4_wait_ready()) goto fail;
  			axes[i] = inb(L4_PORT);
  			if (axes[i] > 252) axes[i] = -1;
  		}
  
  	if (status & 0x10) {
  		if (l4_wait_ready()) goto fail;
  		*buttons = inb(L4_PORT) & 0x0f;
  	}
  
  	result = 0;
  
  fail:	outb(L4_SELECT_ANALOG, L4_PORT);
  	return result;
  }
  
  static int l4_open(struct gameport *gameport, int mode)
  {
  	struct l4 *l4 = gameport->port_data;
  
          if (l4->port != 0 && mode != GAMEPORT_MODE_COOKED)
  		return -1;
  	outb(L4_SELECT_ANALOG, L4_PORT);
  	return 0;
  }
  
  /*
   * l4_getcal() reads the L4 with calibration values.
   */
  
  static int l4_getcal(int port, int *cal)
  {
  	int i, result = -1;
  
  	outb(L4_SELECT_ANALOG, L4_PORT);
  	outb(L4_SELECT_DIGITAL + (port >> 2), L4_PORT);
  	if (inb(L4_PORT) & L4_BUSY)
  		goto out;
  
  	outb(L4_CMD_GETCAL, L4_PORT);
  	if (l4_wait_ready())
  		goto out;
  
  	if (inb(L4_PORT) != L4_SELECT_DIGITAL + (port >> 2))
  		goto out;
  
  	if (l4_wait_ready())
  		goto out;
          outb(port & 3, L4_PORT);
  
  	for (i = 0; i < 4; i++) {
  		if (l4_wait_ready())
  			goto out;
  		cal[i] = inb(L4_PORT);
  	}
  
  	result = 0;
  
  out:	outb(L4_SELECT_ANALOG, L4_PORT);
  	return result;
  }
  
  /*
   * l4_setcal() programs the L4 with calibration values.
   */
  
  static int l4_setcal(int port, int *cal)
  {
  	int i, result = -1;
  
  	outb(L4_SELECT_ANALOG, L4_PORT);
  	outb(L4_SELECT_DIGITAL + (port >> 2), L4_PORT);
  	if (inb(L4_PORT) & L4_BUSY)
  		goto out;
  
  	outb(L4_CMD_SETCAL, L4_PORT);
  	if (l4_wait_ready())
  		goto out;
  
  	if (inb(L4_PORT) != L4_SELECT_DIGITAL + (port >> 2))
  		goto out;
  
  	if (l4_wait_ready())
  		goto out;
          outb(port & 3, L4_PORT);
  
  	for (i = 0; i < 4; i++) {
  		if (l4_wait_ready())
  			goto out;
  		outb(cal[i], L4_PORT);
  	}
  
  	result = 0;
  
  out:	outb(L4_SELECT_ANALOG, L4_PORT);
  	return result;
  }
  
  /*
   * l4_calibrate() calibrates the L4 for the attached device, so
   * that the device's resistance fits into the L4's 8-bit range.
   */
  
  static int l4_calibrate(struct gameport *gameport, int *axes, int *max)
  {
  	int i, t;
  	int cal[4];
  	struct l4 *l4 = gameport->port_data;
  
  	if (l4_getcal(l4->port, cal))
  		return -1;
  
  	for (i = 0; i < 4; i++) {
  		t = (max[i] * cal[i]) / 200;
  		t = (t < 1) ? 1 : ((t > 255) ? 255 : t);
  		axes[i] = (axes[i] < 0) ? -1 : (axes[i] * cal[i]) / t;
  		axes[i] = (axes[i] > 252) ? 252 : axes[i];
  		cal[i] = t;
  	}
  
  	if (l4_setcal(l4->port, cal))
  		return -1;
  
  	return 0;
  }
  
  static int __init l4_create_ports(int card_no)
  {
  	struct l4 *l4;
  	struct gameport *port;
  	int i, idx;
  
  	for (i = 0; i < 4; i++) {
  
  		idx = card_no * 4 + i;
  		l4 = &l4_ports[idx];
  
  		if (!(l4->gameport = port = gameport_allocate_port())) {
  			printk(KERN_ERR "lightning: Memory allocation failed
  ");
  			while (--i >= 0) {
  				gameport_free_port(l4->gameport);
  				l4->gameport = NULL;
  			}
  			return -ENOMEM;
  		}
  		l4->port = idx;
  
  		port->port_data = l4;
  		port->open = l4_open;
  		port->cooked_read = l4_cooked_read;
  		port->calibrate = l4_calibrate;
  
  		gameport_set_name(port, "PDPI Lightning 4");
  		gameport_set_phys(port, "isa%04x/gameport%d", L4_PORT, idx);
  
  		if (idx == 0)
  			port->io = L4_PORT;
  	}
  
  	return 0;
  }
  
  static int __init l4_add_card(int card_no)
  {
  	int cal[4] = { 255, 255, 255, 255 };
  	int i, rev, result;
  	struct l4 *l4;
  
  	outb(L4_SELECT_ANALOG, L4_PORT);
  	outb(L4_SELECT_DIGITAL + card_no, L4_PORT);
  
  	if (inb(L4_PORT) & L4_BUSY)
  		return -1;
  	outb(L4_CMD_ID, L4_PORT);
  
  	if (l4_wait_ready())
  		return -1;
  
  	if (inb(L4_PORT) != L4_SELECT_DIGITAL + card_no)
  		return -1;
  
  	if (l4_wait_ready())
  		return -1;
  	if (inb(L4_PORT) != L4_ID)
  		return -1;
  
  	if (l4_wait_ready())
  		return -1;
  	rev = inb(L4_PORT);
  
  	if (!rev)
  		return -1;
  
  	result = l4_create_ports(card_no);
  	if (result)
  		return result;
  
  	printk(KERN_INFO "gameport: PDPI Lightning 4 %s card v%d.%d at %#x
  ",
  		card_no ? "secondary" : "primary", rev >> 4, rev, L4_PORT);
  
  	for (i = 0; i < 4; i++) {
  		l4 = &l4_ports[card_no * 4 + i];
  
  		if (rev > 0x28)		/* on 2.9+ the setcal command works correctly */
  			l4_setcal(l4->port, cal);
  		gameport_register_port(l4->gameport);
  	}
  
  	return 0;
  }
  
  static int __init l4_init(void)
  {
  	int i, cards = 0;
  
  	if (!request_region(L4_PORT, 1, "lightning"))
  		return -EBUSY;
  
  	for (i = 0; i < 2; i++)
  		if (l4_add_card(i) == 0)
  			cards++;
  
  	outb(L4_SELECT_ANALOG, L4_PORT);
  
  	if (!cards) {
  		release_region(L4_PORT, 1);
  		return -ENODEV;
  	}
  
  	return 0;
  }
  
  static void __exit l4_exit(void)
  {
  	int i;
  	int cal[4] = { 59, 59, 59, 59 };
  
  	for (i = 0; i < 8; i++)
  		if (l4_ports[i].gameport) {
  			l4_setcal(l4_ports[i].port, cal);
  			gameport_unregister_port(l4_ports[i].gameport);
  		}
  
  	outb(L4_SELECT_ANALOG, L4_PORT);
  	release_region(L4_PORT, 1);
  }
  
  module_init(l4_init);
  module_exit(l4_exit);