/*      $NetBSD: ingenic_efuse.c,v 1.3 2015/10/14 15:44:57 macallan Exp $ */

/*-
 * Copyright (c) 2015 Michael Lorenz
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * a driver for the 'EFUSE Slave Interface' found on JZ4780
 * more or less 8kBit of non-volatile storage containing things like MAC
 * address, various encryption keys, boot code, serial numbers and parameters.
 * Using it only to get the MAC address for now.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ingenic_efuse.c,v 1.3 2015/10/14 15:44:57 macallan Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/mutex.h>
#include <sys/bus.h>

#include <mips/ingenic/ingenic_var.h>
#include <mips/ingenic/ingenic_regs.h>

#include "opt_ingenic.h"

static int ingenic_efuse_match(device_t, struct cfdata *, void *);
static void ingenic_efuse_attach(device_t, device_t, void *);

struct efuse_softc {
        device_t                sc_dev;
        bus_space_tag_t         sc_iot;
        bus_space_handle_t      sc_ioh;
        uint8_t                 sc_data[0x20];
};

static void ingenic_efuse_read(struct efuse_softc *, int, int, uint8_t *);

void ingenic_set_enaddr(uint8_t *);

CFATTACH_DECL_NEW(ingenic_efuse, sizeof(struct efuse_softc),
    ingenic_efuse_match, ingenic_efuse_attach, NULL, NULL);

/* ARGSUSED */
static int
ingenic_efuse_match(device_t parent, struct cfdata *match, void *aux)
{
        struct apbus_attach_args *aa = aux;

        if (strcmp(aa->aa_name, "efuse") != 0)
                return 0;

        return 1;
}

/* ARGSUSED */
static void
ingenic_efuse_attach(device_t parent, device_t self, void *aux)
{
        struct efuse_softc *sc = device_private(self);
        struct apbus_attach_args *aa = aux;
        int error;

        sc->sc_dev = self;

        sc->sc_iot = aa->aa_bst;

        if (aa->aa_addr == 0)
                aa->aa_addr = JZ_EFUSE;

        error = bus_space_map(aa->aa_bst, aa->aa_addr, 0x30, 0, &sc->sc_ioh);
        if (error) {
                aprint_error_dev(self,
                    "can't map registers for %s: %d\n", aa->aa_name, error);
                return;
        }

        aprint_naive(": Ingenic EFUSE Slave Interface\n");
        aprint_normal(": Ingenic EFUSE Slave Interface\n");
        ingenic_efuse_read(sc, 8, 0x20, sc->sc_data);
        ingenic_set_enaddr(&sc->sc_data[0x1a]);
#ifdef INGENIC_DEBUG
        {
                int i, j;
                for (i = 0; i < 0x20; i += 8) {
                        printf("%02x:", i);
                        for (j = 0; j < 8; j++)
                                printf(" %02x", sc->sc_data[i + j]);
                        printf("\n");
                }
        }
#endif
}

static void
ingenic_efuse_read(struct efuse_softc *sc, int addr, int len, uint8_t *buf)
{
        uint32_t abuf;
        int i;

        /* default, just in case */
        bus_space_write_4(sc->sc_iot, sc->sc_ioh, JZ_EFUCFG, 0x00040000);
        bus_space_write_4(sc->sc_iot, sc->sc_ioh, JZ_EFUCTRL,
                JZ_EFUSE_READ |
                (addr << JZ_EFUSE_ADDR_SHIFT) |
                ((len - 1) << JZ_EFUSE_SIZE_SHIFT));
        do {} while ((bus_space_read_4(sc->sc_iot, sc->sc_ioh, JZ_EFUSTATE) &
                JZ_EFUSE_RD_DONE) == 0);
        for (i = 0; i < len; i += 4) {
                abuf = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
                    JZ_EFUDATA0 + i);
                memcpy(buf, &abuf, 4);
                buf += 4;
        }
}