// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * (c) 1997-1998  Grant R. Guenther <grant@torque.net>
 *
 * This is a low-level driver for the KBIC-951A and KBIC-971A
 * parallel to IDE adapter chips from KingByte Information Systems.
 *
 * The chips are almost identical, however, the wakeup code
 * required for the 971A interferes with the correct operation of
 * the 951A, so this driver registers itself twice, once for
 * each chip.
 */

#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 r12w()          (delay_p, inw(pi->port + 1) & 0xffff)

#define j44(a, b)       ((((a >> 4) & 0x0f) | (b & 0xf0)) ^ 0x88)
#define j53(w)          (((w >> 3) & 0x1f) | ((w >> 4) & 0xe0))


/*
 * cont = 0 - access the IDE register file
 * cont = 1 - access the IDE command set
 */
static int cont_map[2] = { 0x80, 0x40 };

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

        s = cont_map[cont];

        switch (pi->mode) {
        case 0:
                w0(regr | 0x18 | s); w2(4); w2(6); w2(4); w2(1); w0(8);
                a = r1(); w0(0x28); b = r1(); w2(4);
                return j44(a, b);
        case 1:
                w0(regr|0x38 | s); w2(4); w2(6); w2(4); w2(5); w0(8);
                a = r12w(); w2(4);
                return j53(a);
        case 2:
                w0(regr | 0x08 | s); w2(4); w2(6); w2(4); w2(0xa5); w2(0xa1);
                a = r0(); w2(4);
                return a;
        case 3:
        case 4:
        case 5:
                w0(0x20 | s); w2(4); w2(6); w2(4); w3(regr);
                a = r4(); b = r4(); w2(4); w2(0); w2(4);
                return a;
        }

        return -1;
}

static void kbic_write_regr(struct pi_adapter *pi, int cont, int regr, int val)
{
        int s = cont_map[cont];

        switch (pi->mode) {
        case 0:
        case 1:
        case 2:
                w0(regr | 0x10 | s); w2(4); w2(6); w2(4);
                w0(val); w2(5); w2(4);
                break;
        case 3:
        case 4:
        case 5:
                w0(0x20 | s); w2(4); w2(6); w2(4); w3(regr);
                w4(val); w4(val);
                w2(4); w2(0); w2(4);
                break;
        }
}

static void k951_connect(struct pi_adapter *pi)
{
        pi->saved_r0 = r0();
        pi->saved_r2 = r2();
        w2(4);
}

static void k951_disconnect(struct pi_adapter *pi)
{
        w0(pi->saved_r0);
        w2(pi->saved_r2);
}

#define CCP(x)                                          \
        do {                                            \
                w2(0xc4); w0(0xaa); w0(0x55);           \
                w0(0); w0(0xff); w0(0x87);              \
                w0(0x78); w0(x); w2(0xc5);              \
                w2(0xc4); w0(0xff);                     \
        } while (0)

static void k971_connect(struct pi_adapter *pi)
{
        pi->saved_r0 = r0();
        pi->saved_r2 = r2();
        CCP(0x20);
        w2(4);
}

static void k971_disconnect(struct pi_adapter *pi)
{
        CCP(0x30);
        w0(pi->saved_r0);
        w2(pi->saved_r2);
}

/*
 * count must be congruent to 0 MOD 4, but all known applications
 *have this property.
 */
static void kbic_read_block(struct pi_adapter *pi, char *buf, int count)
{
        int k, a, b;

        switch (pi->mode) {
        case 0:
                w0(0x98); w2(4); w2(6); w2(4);
                for (k = 0; k < count / 2; k++) {
                        w2(1); w0(8);
                        a = r1();
                        w0(0x28);
                        b = r1();
                        buf[2 * k] = j44(a, b);
                        w2(5);
                        b = r1();
                        w0(8);
                        a = r1();
                        buf[2 * k + 1] = j44(a, b);
                        w2(4);
                }
                break;
        case 1:
                w0(0xb8); w2(4); w2(6); w2(4);
                for (k = 0; k < count / 4; k++) {
                        w0(0xb8);
                        w2(4); w2(5);
                        w0(8);
                        buf[4 * k] = j53(r12w());
                        w0(0xb8);
                        buf[4 * k + 1] = j53(r12w());
                        w2(4); w2(5);
                        buf[4 * k + 3] = j53(r12w());
                        w0(8);
                        buf[4 * k + 2] = j53(r12w());
                }
                w2(4);
                break;
        case 2:
                w0(0x88); w2(4); w2(6); w2(4);
                for (k = 0; k < count / 2; k++) {
                        w2(0xa0); w2(0xa1);
                        buf[2 * k] = r0();
                        w2(0xa5);
                        buf[2 * k + 1] = r0();
                }
                w2(4);
                break;
        case 3:
                w0(0xa0); w2(4); w2(6); w2(4); w3(0);
                for (k = 0; k < count; k++)
                        buf[k] = r4();
                w2(4); w2(0); w2(4);
                break;
        case 4:
                w0(0xa0); w2(4); w2(6); w2(4); w3(0);
                for (k = 0; k < count / 2; k++)
                        ((u16 *)buf)[k] = r4w();
                w2(4); w2(0); w2(4);
                break;
        case 5:
                w0(0xa0); w2(4); w2(6); w2(4); w3(0);
                for (k = 0; k < count / 4; k++)
                        ((u32 *)buf)[k] = r4l();
                w2(4); w2(0); w2(4);
                break;
        }
}

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

        switch (pi->mode) {
        case 0:
        case 1:
        case 2:
                w0(0x90); w2(4); w2(6); w2(4);
                for (k = 0; k < count / 2; k++) {
                        w0(buf[2 * k + 1]);
                        w2(0); w2(4);
                        w0(buf[2 * k]);
                        w2(5); w2(4);
                }
                break;
        case 3:
                w0(0xa0); w2(4); w2(6); w2(4); w3(0);
                for (k = 0; k < count / 2; k++) {
                        w4(buf[2 * k + 1]);
                        w4(buf[2 * k]);
                }
                w2(4); w2(0); w2(4);
                break;
        case 4:
                w0(0xa0); w2(4); w2(6); w2(4); w3(0);
                for (k = 0; k < count / 2; k++)
                        w4w(swab16(((u16 *)buf)[k]));
                w2(4); w2(0); w2(4);
                break;
        case 5:
                w0(0xa0); w2(4); w2(6); w2(4); w3(0);
                for (k = 0; k < count / 4; k++)
                        w4l(swab16(((u16 *)buf)[2 * k]) |
                            swab16(((u16 *)buf)[2 * k + 1]) << 16);
                w2(4); w2(0); w2(4);
                break;
        }
}

static void kbic_log_adapter(struct pi_adapter *pi, char *chip)
{
        char *mode[6] = { "4-bit", "5/3", "8-bit", "EPP-8", "EPP_16", "EPP-32"};

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

static void k951_log_adapter(struct pi_adapter *pi)
{
        kbic_log_adapter(pi, "KBIC-951A");
}

static void k971_log_adapter(struct pi_adapter *pi)
{
        kbic_log_adapter(pi, "KBIC-971A");
}

static struct pi_protocol k951 = {
        .owner          = THIS_MODULE,
        .name           = "k951",
        .max_mode       = 6,
        .epp_first      = 3,
        .default_delay  = 1,
        .max_units      = 1,
        .write_regr     = kbic_write_regr,
        .read_regr      = kbic_read_regr,
        .write_block    = kbic_write_block,
        .read_block     = kbic_read_block,
        .connect        = k951_connect,
        .disconnect     = k951_disconnect,
        .log_adapter    = k951_log_adapter,
};

static struct pi_protocol k971 = {
        .owner          = THIS_MODULE,
        .name           = "k971",
        .max_mode       = 6,
        .epp_first      = 3,
        .default_delay  = 1,
        .max_units      = 1,
        .write_regr     = kbic_write_regr,
        .read_regr      = kbic_read_regr,
        .write_block    = kbic_write_block,
        .read_block     = kbic_read_block,
        .connect        = k971_connect,
        .disconnect     = k971_disconnect,
        .log_adapter    = k971_log_adapter,
};

static int __init kbic_init(void)
{
        int rv;

        rv = pata_parport_register_driver(&k951);
        if (rv < 0)
                return rv;
        rv = pata_parport_register_driver(&k971);
        if (rv < 0)
                pata_parport_unregister_driver(&k951);
        return rv;
}

static void __exit kbic_exit(void)
{
        pata_parport_unregister_driver(&k951);
        pata_parport_unregister_driver(&k971);
}

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Grant R. Guenther <grant@torque.net>");
MODULE_DESCRIPTION("KingByte Information Systems KBIC-951A and KBIC-971A "
                   "parallel port IDE adapter protocol driver");
module_init(kbic_init)
module_exit(kbic_exit)