/*      $NetBSD: dp8390.c,v 1.2 2012/11/01 14:46:26 isaki Exp $ */

/*
 * This file is derived from sys/arch/i386/stand/lib/netif/dp8390.c
 * NetBSD: dp8390.c,v 1.6 2008/12/14 18:46:33 christos Exp
 */

/*
 * Polling driver for National Semiconductor DS8390/WD83C690 based
 * ethernet adapters.
 *
 * Copyright (c) 1998 Matthias Drochner.  All rights reserved.
 *
 * 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/types.h>

#include <lib/libsa/stand.h>
#include <libx68k.h>

#include <dev/ic/dp8390reg.h>
#include "dp8390.h"
#include "ne.h"

int dp8390_iobase, dp8390_membase, dp8390_memsize;
#if defined(SUPPORT_WD80X3) && defined(SUPPORT_SMC_ULTRA)
int dp8390_is790;
#endif
uint8_t dp8390_cr_proto;
uint8_t dp8390_dcr_reg;

#define WE_IOBASE dp8390_iobase

static u_short rec_page_start;
static u_short rec_page_stop;
static u_short next_packet;

extern u_char eth_myaddr[6];

static void dp8390_read(int, char *, u_short);

#define NIC_GET(reg) inb(WE_IOBASE + (reg) * 2)
#define NIC_PUT(reg, val) outb(WE_IOBASE + (reg) * 2, val)

static void
dp8390_init(void)
{
        int i;

        /*
         * Initialize the NIC in the exact order outlined in the NS manual.
         * This init procedure is "mandatory"...don't change what or when
         * things happen.
         */

        /* Set interface for page 0, remote DMA complete, stopped. */
        NIC_PUT(ED_P0_CR, dp8390_cr_proto | ED_CR_PAGE_0 | ED_CR_STP);

        if ((dp8390_dcr_reg & ED_DCR_LS)) {
                NIC_PUT(ED_P0_DCR, dp8390_dcr_reg);
        } else {
                /*
                 * Set FIFO threshold to 8, No auto-init Remote DMA, byte
                 * order=80x86, byte-wide DMA xfers,
                 */
                NIC_PUT(ED_P0_DCR, ED_DCR_FT1 | ED_DCR_LS);
        }

        /* Clear remote byte count registers. */
        NIC_PUT(ED_P0_RBCR0, 0);
        NIC_PUT(ED_P0_RBCR1, 0);

        /* Tell RCR to do nothing for now. */
        NIC_PUT(ED_P0_RCR, ED_RCR_MON);

        /* Place NIC in internal loopback mode. */
        NIC_PUT(ED_P0_TCR, ED_TCR_LB0);

        /* Set lower bits of byte addressable framing to 0. */
        if (dp8390_is790)
                NIC_PUT(0x09, 0);

        /* Initialize receive buffer ring. */
        NIC_PUT(ED_P0_BNRY, rec_page_start);
        NIC_PUT(ED_P0_PSTART, rec_page_start);
        NIC_PUT(ED_P0_PSTOP, rec_page_stop);

        /*
         * Clear all interrupts.  A '1' in each bit position clears the
         * corresponding flag.
         */
        NIC_PUT(ED_P0_ISR, 0xff);

        /*
         * Disable all interrupts.
         */
        NIC_PUT(ED_P0_IMR, 0);

        /* Program command register for page 1. */
        NIC_PUT(ED_P0_CR, dp8390_cr_proto | ED_CR_PAGE_1 | ED_CR_STP);

        /* Copy out our station address. */
        for (i = 0; i < 6; i++)
                NIC_PUT(ED_P1_PAR0 + i, eth_myaddr[i]);

        /*
         * Set current page pointer to one page after the boundary pointer, as
         * recommended in the National manual.
         */
        next_packet = rec_page_start + 1;
        NIC_PUT(ED_P1_CURR, next_packet);

        /* Program command register for page 0. */
        NIC_PUT(ED_P1_CR, dp8390_cr_proto | ED_CR_PAGE_0 | ED_CR_STP);

        /* directed and broadcast */
        NIC_PUT(ED_P0_RCR, ED_RCR_AB);

        /* Take interface out of loopback. */
        NIC_PUT(ED_P0_TCR, 0);

        /* Fire up the interface. */
        NIC_PUT(ED_P0_CR, dp8390_cr_proto | ED_CR_PAGE_0 | ED_CR_STA);
}

int
dp8390_config(void)
{

        rec_page_start = TX_PAGE_START + ED_TXBUF_SIZE;
        rec_page_stop = TX_PAGE_START + (dp8390_memsize >> ED_PAGE_SHIFT);

        dp8390_init();

        return 0;
}

void
dp8390_stop(void)
{
        int n = 5000;

        /* Stop everything on the interface, and select page 0 registers. */
        NIC_PUT(ED_P0_CR, dp8390_cr_proto | ED_CR_PAGE_0 | ED_CR_STP);

        /*
         * Wait for interface to enter stopped state, but limit # of checks to
         * 'n' (about 5ms).  It shouldn't even take 5us on modern DS8390's, but
         * just in case it's an old one.
         */
        while (((NIC_GET(ED_P0_ISR) & ED_ISR_RST) == 0) && --n)
                continue;
}

int
EtherSend(char *pkt, int len)
{
        ne2000_writemem(pkt, dp8390_membase, len);

        /* Set TX buffer start page. */
        NIC_PUT(ED_P0_TPSR, TX_PAGE_START);

        /* Set TX length. */
        NIC_PUT(ED_P0_TBCR0, len < 60 ? 60 : len);
        NIC_PUT(ED_P0_TBCR1, len >> 8);

        /* Set page 0, remote DMA complete, transmit packet, and *start*. */
        NIC_PUT(ED_P0_CR, dp8390_cr_proto | ED_CR_PAGE_0 | ED_CR_TXP | ED_CR_STA);

        return len;
}

static void
dp8390_read(int buf, char *dest, u_short len)
{
        u_short tmp_amount;

        /* Does copy wrap to lower addr in ring buffer? */
        if (buf + len > dp8390_membase + dp8390_memsize) {
                tmp_amount = dp8390_membase + dp8390_memsize - buf;

                /* Copy amount up to end of NIC memory. */
                ne2000_readmem(buf, dest, tmp_amount);

                len -= tmp_amount;
                buf = RX_BUFBASE + (rec_page_start << ED_PAGE_SHIFT);
                dest += tmp_amount;
        }
        ne2000_readmem(buf, dest, len);
}

int
EtherReceive(char *pkt, int maxlen)
{
        struct dp8390_ring packet_hdr;
        int packet_ptr;
        u_short len;
        u_char boundary, current;
#ifdef DP8390_OLDCHIPS
        u_char nlen;
#endif

        if (!(NIC_GET(ED_P0_RSR) & ED_RSR_PRX))
                return 0; /* XXX error handling */

        /* Set NIC to page 1 registers to get 'current' pointer. */
        NIC_PUT(ED_P0_CR, dp8390_cr_proto | ED_CR_PAGE_1 | ED_CR_STA);

        /*
         * 'sc->next_packet' is the logical beginning of the ring-buffer - i.e.
         * it points to where new data has been buffered.  The 'CURR' (current)
         * register points to the logical end of the ring-buffer - i.e. it
         * points to where additional new data will be added.  We loop here
         * until the logical beginning equals the logical end (or in other
         * words, until the ring-buffer is empty).
         */
        current = NIC_GET(ED_P1_CURR);

        /* Set NIC to page 0 registers to update boundary register. */
        NIC_PUT(ED_P1_CR, dp8390_cr_proto | ED_CR_PAGE_0 | ED_CR_STA);

        if (next_packet == current)
                return 0;

        /* Get pointer to this buffer's header structure. */
        packet_ptr = RX_BUFBASE + (next_packet << ED_PAGE_SHIFT);

        /*
         * The byte count includes a 4 byte header that was added by
         * the NIC.
         */
        ne2000_readmem(packet_ptr, (void *)&packet_hdr, 4);

        len = le16toh(packet_hdr.count);

#ifdef DP8390_OLDCHIPS
        /*
         * Try do deal with old, buggy chips that sometimes duplicate
         * the low byte of the length into the high byte.  We do this
         * by simply ignoring the high byte of the length and always
         * recalculating it.
         *
         * NOTE: sc->next_packet is pointing at the current packet.
         */
        if (packet_hdr.next_packet >= next_packet)
                nlen = (packet_hdr.next_packet - next_packet);
        else
                nlen = ((packet_hdr.next_packet - rec_page_start) +
                        (rec_page_stop - next_packet));
        --nlen;
        if ((len & ED_PAGE_MASK) + sizeof(packet_hdr) > ED_PAGE_SIZE)
                --nlen;
        len = (len & ED_PAGE_MASK) | (nlen << ED_PAGE_SHIFT);
#ifdef DIAGNOSTIC
        if (len != packet_hdr.count) {
                printf(IFNAME ": length does not match next packet pointer\n");
                printf(IFNAME ": len %04x nlen %04x start %02x "
                       "first %02x curr %02x next %02x stop %02x\n",
                       packet_hdr.count, len,
                       rec_page_start, next_packet, current,
                       packet_hdr.next_packet, rec_page_stop);
        }
#endif
#endif

        if (packet_hdr.next_packet < rec_page_start ||
            packet_hdr.next_packet >= rec_page_stop)
                panic(IFNAME ": RAM corrupt");

        len -= sizeof(struct dp8390_ring);
        if (len <= maxlen) {
                /* Go get packet. */
                dp8390_read(packet_ptr + sizeof(struct dp8390_ring),
                            pkt, len);
        } else
                len = 0;

        /* Update next packet pointer. */
        next_packet = packet_hdr.next_packet;

        /*
         * Update NIC boundary pointer - being careful to keep it one
         * buffer behind (as recommended by NS databook).
         */
        boundary = next_packet - 1;
        if (boundary < rec_page_start)
                boundary = rec_page_stop - 1;
        NIC_PUT(ED_P0_BNRY, boundary);

        return len;
}