/*      $NetBSD: if_ae.c,v 1.80 2010/01/19 22:06:20 pooka Exp $ */

/*
 * Device driver for National Semiconductor DS8390/WD83C690 based ethernet
 * adapters.
 *
 * Copyright (c) 1994, 1995 Charles M. Hannum.  All rights reserved.
 *
 * Copyright (C) 1993, David Greenman.  This software may be used, modified,
 * copied, distributed, and sold, in both source and binary form provided that
 * the above copyright and these terms are retained.  Under no circumstances is
 * the author responsible for the proper functioning of this software, nor does
 * the author assume any responsibility for damages incurred with its use.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_ae.c,v 1.80 2010/01/19 22:06:20 pooka Exp $");


#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/mbuf.h>
#include <sys/socket.h>

#include <net/if.h>
#include <net/if_media.h>
#include <net/if_ether.h>

#include <machine/bus.h>

#include <dev/ic/dp8390reg.h>
#include <dev/ic/dp8390var.h>
#include <mac68k/dev/if_aevar.h>

#define ETHER_PAD_LEN   (ETHER_MIN_LEN - ETHER_CRC_LEN)

int
ae_size_card_memory(bus_space_tag_t bst, bus_space_handle_t bsh, int ofs)
{
        int i1, i2, i3, i4, i8;

        /*
         * banks; also assume it will generally mirror in upper banks
         * if not installed.
         */
        i1 = (8192 * 0);
        i2 = (8192 * 1);
        i3 = (8192 * 2);
        i4 = (8192 * 3);

        i8 = (8192 * 4);

        bus_space_write_2(bst, bsh, ofs + i8, 0x8888);
        bus_space_write_2(bst, bsh, ofs + i4, 0x4444);
        bus_space_write_2(bst, bsh, ofs + i3, 0x3333);
        bus_space_write_2(bst, bsh, ofs + i2, 0x2222);
        bus_space_write_2(bst, bsh, ofs + i1, 0x1111);

        /*
        * 1) If the memory range is decoded completely, it does not
        *    matter what we write first: High tags written into
        *    the void are lost.
        * 2) If the memory range is not decoded completely (banks are
        *    mirrored), high tags are overwritten by lower ones.
        * 3) Lazy implementation of pathological cases - none found yet.
        */

        if (bus_space_read_2(bst, bsh, ofs + i1) == 0x1111 &&
            bus_space_read_2(bst, bsh, ofs + i2) == 0x2222 &&
            bus_space_read_2(bst, bsh, ofs + i3) == 0x3333 &&
            bus_space_read_2(bst, bsh, ofs + i4) == 0x4444 &&
            bus_space_read_2(bst, bsh, ofs + i8) == 0x8888)
                return 8192 * 8;

        if (bus_space_read_2(bst, bsh, ofs + i1) == 0x1111 &&
            bus_space_read_2(bst, bsh, ofs + i2) == 0x2222 &&
            bus_space_read_2(bst, bsh, ofs + i3) == 0x3333 &&
            bus_space_read_2(bst, bsh, ofs + i4) == 0x4444)
                return 8192 * 4;

        if ((bus_space_read_2(bst, bsh, ofs + i1) == 0x1111 &&
            bus_space_read_2(bst, bsh, ofs + i2) == 0x2222) ||
            (bus_space_read_2(bst, bsh, ofs + i1) == 0x3333 &&
            bus_space_read_2(bst, bsh, ofs + i2) == 0x4444))
                return 8192 * 2;

        if (bus_space_read_2(bst, bsh, ofs + i1) == 0x1111 ||
            bus_space_read_2(bst, bsh, ofs + i1) == 0x4444)
                return 8192;

        return 0;
}

/*
 * Zero memory and verify that it is clear.  The only difference between
 * this and the default test_mem function is that the DP8390-based NuBus
 * cards * apparently require word-wide writes and byte-wide reads, an
 * `interesting' combination.
 */
int
ae_test_mem(struct dp8390_softc *sc)
{
        bus_space_tag_t buft = sc->sc_buft;
        bus_space_handle_t bufh = sc->sc_bufh;
        int i;

        bus_space_set_region_2(buft, bufh, sc->mem_start, 0,
            sc->mem_size / 2);

        for (i = 0; i < sc->mem_size; ++i) {
                if (bus_space_read_1(sc->sc_buft, sc->sc_bufh, i)) {
                        printf(": failed to clear NIC buffer at offset %x - "
                            "check configuration\n", (sc->mem_start + i));
                        return 1;
                }
        }

        return 0;
}

/*
 * Copy packet from mbuf to the board memory Currently uses an extra
 * buffer/extra memory copy, unless the whole packet fits in one mbuf.
 *
 * As in the test_mem function, we use word-wide writes.
 */
int
ae_write_mbuf(struct dp8390_softc *sc, struct mbuf *m, int buf)
{
        u_char *data, savebyte[2];
        int len, wantbyte;
        u_short totlen = 0;

        wantbyte = 0;

        for (; m ; m = m->m_next) {
                data = mtod(m, u_char *);
                len = m->m_len;
                totlen += len;
                if (len > 0) {
                        /* Finish the last word. */
                        if (wantbyte) {
                                savebyte[1] = *data;
                                bus_space_write_region_2(sc->sc_buft,
                                    sc->sc_bufh, buf, (u_int16_t *)savebyte, 1);
                                buf += 2;
                                data++;
                                len--;
                                wantbyte = 0;
                        }
                        /* Output contiguous words. */
                        if (len > 1) {
                                bus_space_write_region_2(
                                    sc->sc_buft, sc->sc_bufh,
                                    buf, (u_int16_t *)data, len >> 1);
                                buf += len & ~1;
                                data += len & ~1;
                                len &= 1;
                        }
                        /* Save last byte, if necessary. */
                        if (len == 1) {
                                savebyte[0] = *data;
                                wantbyte = 1;
                        }
                }
        }

        len = ETHER_PAD_LEN - totlen;
        if (wantbyte) {
                savebyte[1] = 0;
                bus_space_write_region_2(sc->sc_buft, sc->sc_bufh,
                    buf, (u_int16_t *)savebyte, 1);
                buf += 2;
                totlen++;
                len--;
        }
        /* if sent data is shorter than EHTER_PAD_LEN, put 0 to padding */
        if (len > 0) {
                bus_space_set_region_2(sc->sc_buft, sc->sc_bufh, buf, 0,
                    len >> 1);
                totlen = ETHER_PAD_LEN;
        }
        return (totlen);
}