// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright (c) 1998-2001 Vojtech Pavlik
 */

/*
 * PDPI Lightning 4 gamecard driver for Linux.
 */

#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\n");
                        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\n",
                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);