// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * (c) 1998  Grant R. Guenther <grant@torque.net>
 *
 * fit3.c is a low-level protocol driver for newer models
 * of the Fidelity International Technology parallel port adapter.
 * This adapter is used in their TransDisk 3000 portable
 * hard-drives, as well as CD-ROM, PD-CD and other devices.
 *
 * The TD-2000 and certain older devices use a different protocol.
 * Try the fit2 protocol module with them.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/wait.h>
#include <asm/io.h>
#include "pata_parport.h"

#define j44(a, b)       (((a >> 3) & 0x0f) | ((b << 1) & 0xf0))

#define w7(byte)        out_p(7, byte)
#define r7()            (in_p(7) & 0xff)

/*
 * cont = 0 - access the IDE register file
 * cont = 1 - access the IDE command set
 */

static void fit3_write_regr(struct pi_adapter *pi, int cont, int regr, int val)
{
        regr += cont << 3;

        switch (pi->mode) {
        case 0:
        case 1:
                w2(0xc); w0(regr); w2(0x8); w2(0xc);
                w0(val); w2(0xd);
                w0(0);   w2(0xc);
                break;
        case 2:
                w2(0xc); w0(regr); w2(0x8); w2(0xc);
                w4(val); w4(0);
                w2(0xc);
                break;
        }
}

static int fit3_read_regr(struct pi_adapter *pi, int cont, int regr)
{
        int  a, b;

        regr += cont << 3;

        switch (pi->mode) {
        case 0:
                w2(0xc); w0(regr + 0x10); w2(0x8); w2(0xc);
                w2(0xd); a = r1();
                w2(0xf); b = r1();
                w2(0xc);
                return j44(a, b);
        case 1:
                w2(0xc); w0(regr + 0x90); w2(0x8); w2(0xc);
                w2(0xec); w2(0xee); w2(0xef); a = r0();
                w2(0xc);
                return a;
        case 2:
                w2(0xc); w0(regr + 0x90); w2(0x8); w2(0xc);
                w2(0xec);
                a = r4(); b = r4();
                w2(0xc);
                return a;
        }

        return -1;
}

static void fit3_read_block(struct pi_adapter *pi, char *buf, int count)
{
        int  k, a, b, c, d;

        switch (pi->mode) {
        case 0:
                w2(0xc); w0(0x10); w2(0x8); w2(0xc);
                for (k = 0; k < count / 2; k++) {
                        w2(0xd); a = r1();
                        w2(0xf); b = r1();
                        w2(0xc); c = r1();
                        w2(0xe); d = r1();
                        buf[2 * k] = j44(a, b);
                        buf[2 * k + 1] = j44(c, d);
                }
                w2(0xc);
                break;
        case 1:
                w2(0xc); w0(0x90); w2(0x8); w2(0xc);
                w2(0xec); w2(0xee);
                for (k = 0; k < count / 2; k++) {
                        w2(0xef); a = r0();
                        w2(0xee); b = r0();
                        buf[2 * k] = a;
                        buf[2 * k + 1] = b;
                }
                w2(0xec);
                w2(0xc);
                break;
        case 2:
                w2(0xc); w0(0x90); w2(0x8); w2(0xc);
                w2(0xec);
                for (k = 0; k < count; k++)
                        buf[k] = r4();
                w2(0xc);
                break;
        }
}

static void fit3_write_block(struct pi_adapter *pi, char *buf, int count)
{
        int k;

        switch (pi->mode) {
        case 0:
        case 1:
                w2(0xc); w0(0); w2(0x8); w2(0xc);
                for (k = 0; k < count / 2; k++) {
                        w0(buf[2 * k]); w2(0xd);
                        w0(buf[2 * k + 1]); w2(0xc);
                }
                break;
        case 2:
                w2(0xc); w0(0); w2(0x8); w2(0xc);
                for (k = 0; k < count; k++)
                        w4(buf[k]);
                w2(0xc);
                break;
        }
}

static void fit3_connect(struct pi_adapter *pi)
{
        pi->saved_r0 = r0();
        pi->saved_r2 = r2();
        w2(0xc); w0(0); w2(0xa);
        if (pi->mode == 2) {
                w2(0xc); w0(0x9);
                w2(0x8); w2(0xc);
        }
}

static void fit3_disconnect(struct pi_adapter *pi)
{
        w2(0xc); w0(0xa); w2(0x8); w2(0xc);
        w0(pi->saved_r0);
        w2(pi->saved_r2);
}

static void fit3_log_adapter(struct pi_adapter *pi)
{
        char *mode_string[3] = { "4-bit", "8-bit", "EPP"};

        dev_info(&pi->dev,
                 "FIT 3000 adapter at 0x%x, mode %d (%s), delay %d\n",
                 pi->port, pi->mode, mode_string[pi->mode], pi->delay);
}

static struct pi_protocol fit3 = {
        .owner          = THIS_MODULE,
        .name           = "fit3",
        .max_mode       = 3,
        .epp_first      = 2,
        .default_delay  = 1,
        .max_units      = 1,
        .write_regr     = fit3_write_regr,
        .read_regr      = fit3_read_regr,
        .write_block    = fit3_write_block,
        .read_block     = fit3_read_block,
        .connect        = fit3_connect,
        .disconnect     = fit3_disconnect,
        .log_adapter    = fit3_log_adapter,
};

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Grant R. Guenther <grant@torque.net>");
MODULE_DESCRIPTION("Fidelity International Technology parallel port IDE adapter"
                   "(newer models) protocol driver");
module_pata_parport_driver(fit3);