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mx98905.c revision 1.1
      1  1.1  bjh21 /*	$NetBSD: mx98905.c,v 1.1 2001/12/15 17:47:35 bjh21 Exp $	*/
      2  1.1  bjh21 
      3  1.1  bjh21 /*-
      4  1.1  bjh21  * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
      5  1.1  bjh21  * All rights reserved.
      6  1.1  bjh21  *
      7  1.1  bjh21  * This code is derived from software contributed to The NetBSD Foundation
      8  1.1  bjh21  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
      9  1.1  bjh21  * NASA Ames Research Center.
     10  1.1  bjh21  *
     11  1.1  bjh21  * Redistribution and use in source and binary forms, with or without
     12  1.1  bjh21  * modification, are permitted provided that the following conditions
     13  1.1  bjh21  * are met:
     14  1.1  bjh21  * 1. Redistributions of source code must retain the above copyright
     15  1.1  bjh21  *    notice, this list of conditions and the following disclaimer.
     16  1.1  bjh21  * 2. Redistributions in binary form must reproduce the above copyright
     17  1.1  bjh21  *    notice, this list of conditions and the following disclaimer in the
     18  1.1  bjh21  *    documentation and/or other materials provided with the distribution.
     19  1.1  bjh21  * 3. All advertising materials mentioning features or use of this software
     20  1.1  bjh21  *    must display the following acknowledgement:
     21  1.1  bjh21  *	This product includes software developed by the NetBSD
     22  1.1  bjh21  *	Foundation, Inc. and its contributors.
     23  1.1  bjh21  * 4. Neither the name of The NetBSD Foundation nor the names of its
     24  1.1  bjh21  *    contributors may be used to endorse or promote products derived
     25  1.1  bjh21  *    from this software without specific prior written permission.
     26  1.1  bjh21  *
     27  1.1  bjh21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     28  1.1  bjh21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     29  1.1  bjh21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     30  1.1  bjh21  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     31  1.1  bjh21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     32  1.1  bjh21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     33  1.1  bjh21  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     34  1.1  bjh21  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     35  1.1  bjh21  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     36  1.1  bjh21  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     37  1.1  bjh21  * POSSIBILITY OF SUCH DAMAGE.
     38  1.1  bjh21  */
     39  1.1  bjh21 
     40  1.1  bjh21 /*
     41  1.1  bjh21  * Device driver for National Semiconductor DS8390/WD83C690 based ethernet
     42  1.1  bjh21  * adapters.
     43  1.1  bjh21  *
     44  1.1  bjh21  * Copyright (c) 1994, 1995 Charles M. Hannum.  All rights reserved.
     45  1.1  bjh21  *
     46  1.1  bjh21  * Copyright (C) 1993, David Greenman.  This software may be used, modified,
     47  1.1  bjh21  * copied, distributed, and sold, in both source and binary form provided that
     48  1.1  bjh21  * the above copyright and these terms are retained.  Under no circumstances is
     49  1.1  bjh21  * the author responsible for the proper functioning of this software, nor does
     50  1.1  bjh21  * the author assume any responsibility for damages incurred with its use.
     51  1.1  bjh21  */
     52  1.1  bjh21 
     53  1.1  bjh21 /*
     54  1.1  bjh21  * Special routines for the Macronix MX 98905.  For use with the "ne" driver.
     55  1.1  bjh21  */
     56  1.1  bjh21 
     57  1.1  bjh21 /*
     58  1.1  bjh21  * <URL:http://mail-index.netbsd.org/port-arm32/1996/06/23/0005.html>:
     59  1.1  bjh21  * There are 2 types of etherh card.  One uses the macronics chipset MX98905
     60  1.1  bjh21  * and that chipset has a bug in it, in that it the MSB remote dma
     61  1.1  bjh21  * register does not work.  There is a workaround for this which
     62  1.1  bjh21  * should be around soon.  In fact, I think only the buffer ram test
     63  1.1  bjh21  * ever transfers more than 256 bytes across the dma channel, so diabling
     64  1.1  bjh21  * it will make the mx stuff work.
     65  1.1  bjh21  */
     66  1.1  bjh21 
     67  1.1  bjh21 #include <sys/param.h>
     68  1.1  bjh21 
     69  1.1  bjh21 __KERNEL_RCSID(0, "$NetBSD: mx98905.c,v 1.1 2001/12/15 17:47:35 bjh21 Exp $");
     70  1.1  bjh21 
     71  1.1  bjh21 #include <sys/device.h>
     72  1.1  bjh21 #include <sys/mbuf.h>
     73  1.1  bjh21 #include <sys/socket.h>
     74  1.1  bjh21 #include <sys/syslog.h>
     75  1.1  bjh21 #include <sys/systm.h>
     76  1.1  bjh21 
     77  1.1  bjh21 #include <net/if.h>
     78  1.1  bjh21 #include <net/if_ether.h>
     79  1.1  bjh21 #include <net/if_media.h>
     80  1.1  bjh21 
     81  1.1  bjh21 #include <machine/bus.h>
     82  1.1  bjh21 
     83  1.1  bjh21 #include <dev/ic/dp8390reg.h>
     84  1.1  bjh21 #include <dev/ic/dp8390var.h>
     85  1.1  bjh21 #include <dev/ic/ne2000reg.h>
     86  1.1  bjh21 #include <dev/ic/ne2000var.h>
     87  1.1  bjh21 #include <dev/ic/mx98905var.h>
     88  1.1  bjh21 
     89  1.1  bjh21 #ifndef __BUS_SPACE_HAS_STREAM_METHODS
     90  1.1  bjh21 #define	bus_space_write_stream_2	bus_space_write_2
     91  1.1  bjh21 #define	bus_space_write_multi_stream_2	bus_space_write_multi_2
     92  1.1  bjh21 #define	bus_space_read_multi_stream_2	bus_space_read_multi_2
     93  1.1  bjh21 #endif /* __BUS_SPACE_HAS_STREAM_METHODS */
     94  1.1  bjh21 
     95  1.1  bjh21 void
     96  1.1  bjh21 mx98905_attach(struct dp8390_softc *sc)
     97  1.1  bjh21 {
     98  1.1  bjh21 
     99  1.1  bjh21 	sc->ring_copy = mx98905_ring_copy;
    100  1.1  bjh21 	sc->write_mbuf = mx98905_write_mbuf;
    101  1.1  bjh21 	sc->read_hdr = mx98905_read_hdr;
    102  1.1  bjh21 }
    103  1.1  bjh21 
    104  1.1  bjh21 static __inline void
    105  1.1  bjh21 mx98905_write_setup(sc, len, buf)
    106  1.1  bjh21 	struct dp8390_softc *sc;
    107  1.1  bjh21 	int len, buf;
    108  1.1  bjh21 {
    109  1.1  bjh21 	bus_space_tag_t nict = sc->sc_regt;
    110  1.1  bjh21 	bus_space_handle_t nich = sc->sc_regh;
    111  1.1  bjh21 
    112  1.1  bjh21 	/* Select page 0 registers. */
    113  1.1  bjh21 	NIC_BARRIER(nict, nich);
    114  1.1  bjh21 	bus_space_write_1(nict, nich, ED_P0_CR,
    115  1.1  bjh21 	    ED_CR_RD2 | ED_CR_PAGE_0 | ED_CR_STA);
    116  1.1  bjh21 	NIC_BARRIER(nict, nich);
    117  1.1  bjh21 
    118  1.1  bjh21 	/* Reset remote DMA complete flag. */
    119  1.1  bjh21 	bus_space_write_1(nict, nich, ED_P0_ISR, ED_ISR_RDC);
    120  1.1  bjh21 	NIC_BARRIER(nict, nich);
    121  1.1  bjh21 
    122  1.1  bjh21 	/* Set up DMA byte count. */
    123  1.1  bjh21 	bus_space_write_1(nict, nich, ED_P0_RBCR0, len);
    124  1.1  bjh21 	bus_space_write_1(nict, nich, ED_P0_RBCR1, len >> 8);
    125  1.1  bjh21 
    126  1.1  bjh21 	/* Set up destination address in NIC mem. */
    127  1.1  bjh21 	bus_space_write_1(nict, nich, ED_P0_RSAR0, buf);
    128  1.1  bjh21 	bus_space_write_1(nict, nich, ED_P0_RSAR1, buf >> 8);
    129  1.1  bjh21 
    130  1.1  bjh21 	/* Set remote DMA write. */
    131  1.1  bjh21 	NIC_BARRIER(nict, nich);
    132  1.1  bjh21 	bus_space_write_1(nict, nich,
    133  1.1  bjh21 	    ED_P0_CR, ED_CR_RD1 | ED_CR_PAGE_0 | ED_CR_STA);
    134  1.1  bjh21 	NIC_BARRIER(nict, nich);
    135  1.1  bjh21 }
    136  1.1  bjh21 
    137  1.1  bjh21 
    138  1.1  bjh21 static __inline void
    139  1.1  bjh21 mx98905_write_wait(sc)
    140  1.1  bjh21 	struct dp8390_softc *sc;
    141  1.1  bjh21 {
    142  1.1  bjh21 	int maxwait = 100;	/* about 120us */
    143  1.1  bjh21 	bus_space_tag_t nict = sc->sc_regt;
    144  1.1  bjh21 	bus_space_handle_t nich = sc->sc_regh;
    145  1.1  bjh21 
    146  1.1  bjh21 	/*
    147  1.1  bjh21 	 * Wait for remote DMA to complete.  This is necessary because on the
    148  1.1  bjh21 	 * transmit side, data is handled internally by the NIC in bursts, and
    149  1.1  bjh21 	 * we can't start another remote DMA until this one completes.  Not
    150  1.1  bjh21 	 * waiting causes really bad things to happen - like the NIC wedging
    151  1.1  bjh21 	 * the bus.
    152  1.1  bjh21 	 */
    153  1.1  bjh21 	while (((bus_space_read_1(nict, nich, ED_P0_ISR) & ED_ISR_RDC) !=
    154  1.1  bjh21 	    ED_ISR_RDC) && --maxwait) {
    155  1.1  bjh21 		bus_space_read_1(nict, nich, ED_P0_CRDA1);
    156  1.1  bjh21 		bus_space_read_1(nict, nich, ED_P0_CRDA0);
    157  1.1  bjh21 		NIC_BARRIER(nict, nich);
    158  1.1  bjh21 		DELAY(1);
    159  1.1  bjh21 	}
    160  1.1  bjh21 
    161  1.1  bjh21 	if (maxwait == 0) {
    162  1.1  bjh21 		log(LOG_WARNING,
    163  1.1  bjh21 		    "%s: remote transmit DMA failed to complete\n",
    164  1.1  bjh21 		    sc->sc_dev.dv_xname);
    165  1.1  bjh21 		dp8390_reset(sc);
    166  1.1  bjh21 	}
    167  1.1  bjh21 }
    168  1.1  bjh21 
    169  1.1  bjh21 /*
    170  1.1  bjh21  * Write an mbuf chain to the destination NIC memory address using programmed
    171  1.1  bjh21  * I/O.
    172  1.1  bjh21  */
    173  1.1  bjh21 int
    174  1.1  bjh21 mx98905_write_mbuf(sc, m, buf)
    175  1.1  bjh21 	struct dp8390_softc *sc;
    176  1.1  bjh21 	struct mbuf *m;
    177  1.1  bjh21 	int buf;
    178  1.1  bjh21 {
    179  1.1  bjh21 	struct ne2000_softc *nsc = (struct ne2000_softc *)sc;
    180  1.1  bjh21 	bus_space_tag_t nict = sc->sc_regt;
    181  1.1  bjh21 	bus_space_handle_t nich = sc->sc_regh;
    182  1.1  bjh21 	bus_space_tag_t asict = nsc->sc_asict;
    183  1.1  bjh21 	bus_space_handle_t asich = nsc->sc_asich;
    184  1.1  bjh21 	int savelen, dmalen, resid, len;
    185  1.1  bjh21 	u_int8_t *data, savebyte[2];
    186  1.1  bjh21 	int l, leftover;
    187  1.1  bjh21 #ifdef DIAGNOSTIC
    188  1.1  bjh21 	u_int8_t *lim;
    189  1.1  bjh21 #endif
    190  1.1  bjh21 
    191  1.1  bjh21 	resid = savelen = m->m_pkthdr.len;
    192  1.1  bjh21 
    193  1.1  bjh21 	dmalen = min(resid, 254);
    194  1.1  bjh21 
    195  1.1  bjh21 	mx98905_write_setup(sc, dmalen, buf);
    196  1.1  bjh21 
    197  1.1  bjh21 	buf += dmalen;
    198  1.1  bjh21 	resid -= dmalen;
    199  1.1  bjh21 
    200  1.1  bjh21 	/*
    201  1.1  bjh21 	 * Transfer the mbuf chain to the NIC memory.  NE2000 cards
    202  1.1  bjh21 	 * require that data be transferred as words, and only words,
    203  1.1  bjh21 	 * so that case requires some extra code to patch over odd-length
    204  1.1  bjh21 	 * mbufs.
    205  1.1  bjh21 	 */
    206  1.1  bjh21 	/* NE2000s are a bit trickier. */
    207  1.1  bjh21 	/* Start out with no leftover data. */
    208  1.1  bjh21 	leftover = 0;
    209  1.1  bjh21 	savebyte[0] = savebyte[1] = 0;
    210  1.1  bjh21 
    211  1.1  bjh21 	for (; m != 0; m = m->m_next) {
    212  1.1  bjh21 		l = m->m_len;
    213  1.1  bjh21 		if (l == 0)
    214  1.1  bjh21 			continue;
    215  1.1  bjh21 		data = mtod(m, u_int8_t *);
    216  1.1  bjh21 #ifdef DIAGNOSTIC
    217  1.1  bjh21 		lim = data + l;
    218  1.1  bjh21 #endif
    219  1.1  bjh21 		while (l > 0) {
    220  1.1  bjh21 			if (leftover) {
    221  1.1  bjh21 				/*
    222  1.1  bjh21 				 * Data left over (from mbuf or
    223  1.1  bjh21 				 * realignment).  Buffer the next
    224  1.1  bjh21 				 * byte, and write it and the leftover
    225  1.1  bjh21 				 * data out.
    226  1.1  bjh21 				 */
    227  1.1  bjh21 				savebyte[1] = *data++;
    228  1.1  bjh21 				l--;
    229  1.1  bjh21 				bus_space_write_stream_2(asict, asich,
    230  1.1  bjh21 				    NE2000_ASIC_DATA, *(u_int16_t *)savebyte);
    231  1.1  bjh21 				dmalen -= 2;
    232  1.1  bjh21 				leftover = 0;
    233  1.1  bjh21 			} else if (BUS_SPACE_ALIGNED_POINTER(data,
    234  1.1  bjh21 			    u_int16_t) == 0) {
    235  1.1  bjh21 				/* Unaligned data; buffer the next byte. */
    236  1.1  bjh21 				savebyte[0] = *data++;
    237  1.1  bjh21 				l--;
    238  1.1  bjh21 				leftover = 1;
    239  1.1  bjh21 			} else {
    240  1.1  bjh21 				/*
    241  1.1  bjh21 				 * Aligned data; output contiguous
    242  1.1  bjh21 				 * words as much as we can, then
    243  1.1  bjh21 				 * buffer the remaining byte, if any.
    244  1.1  bjh21 				 */
    245  1.1  bjh21 				len = min(l, dmalen);
    246  1.1  bjh21 				leftover = len & 1;
    247  1.1  bjh21 				len &= ~1;
    248  1.1  bjh21 				bus_space_write_multi_stream_2(asict,
    249  1.1  bjh21 				    asich, NE2000_ASIC_DATA,
    250  1.1  bjh21 				    (u_int16_t *)data, len >> 1);
    251  1.1  bjh21 				dmalen -= len;
    252  1.1  bjh21 				data += len;
    253  1.1  bjh21 				if (leftover)
    254  1.1  bjh21 					savebyte[0] = *data++;
    255  1.1  bjh21 				l -= len + leftover;
    256  1.1  bjh21 			}
    257  1.1  bjh21 			if (dmalen == 0 && resid > 0) {
    258  1.1  bjh21 				mx98905_write_wait(sc);
    259  1.1  bjh21 				dmalen = min(resid, 254);
    260  1.1  bjh21 
    261  1.1  bjh21 				mx98905_write_setup(sc, dmalen, buf);
    262  1.1  bjh21 
    263  1.1  bjh21 				buf += dmalen;
    264  1.1  bjh21 				resid -= dmalen;
    265  1.1  bjh21 			}
    266  1.1  bjh21 		}
    267  1.1  bjh21 		if (l < 0)
    268  1.1  bjh21 			panic("mx98905_write_mbuf: negative len");
    269  1.1  bjh21 #ifdef DIAGNOSTIC
    270  1.1  bjh21 		if (data != lim)
    271  1.1  bjh21 			panic("mx98905_write_mbuf: data != lim");
    272  1.1  bjh21 #endif
    273  1.1  bjh21 	}
    274  1.1  bjh21 	if (leftover) {
    275  1.1  bjh21 		savebyte[1] = 0;
    276  1.1  bjh21 		bus_space_write_stream_2(asict, asich, NE2000_ASIC_DATA,
    277  1.1  bjh21 		    *(u_int16_t *)savebyte);
    278  1.1  bjh21 	}
    279  1.1  bjh21 	NIC_BARRIER(nict, nich);
    280  1.1  bjh21 
    281  1.1  bjh21 	mx98905_write_wait(sc);
    282  1.1  bjh21 
    283  1.1  bjh21 	return (savelen);
    284  1.1  bjh21 }
    285  1.1  bjh21 
    286  1.1  bjh21 /*
    287  1.1  bjh21  * Given a source and destination address, copy 'amout' of a packet from
    288  1.1  bjh21  * the ring buffer into a linear destination buffer.  Takes into account
    289  1.1  bjh21  * ring-wrap.
    290  1.1  bjh21  */
    291  1.1  bjh21 int
    292  1.1  bjh21 mx98905_ring_copy(sc, src, dst, amount)
    293  1.1  bjh21 	struct dp8390_softc *sc;
    294  1.1  bjh21 	int src;
    295  1.1  bjh21 	caddr_t dst;
    296  1.1  bjh21 	u_short amount;
    297  1.1  bjh21 {
    298  1.1  bjh21 	struct ne2000_softc *nsc = (struct ne2000_softc *)sc;
    299  1.1  bjh21 	bus_space_tag_t nict = sc->sc_regt;
    300  1.1  bjh21 	bus_space_handle_t nich = sc->sc_regh;
    301  1.1  bjh21 	bus_space_tag_t asict = nsc->sc_asict;
    302  1.1  bjh21 	bus_space_handle_t asich = nsc->sc_asich;
    303  1.1  bjh21 	u_short tmp_amount;
    304  1.1  bjh21 	int useword = NE2000_USE_WORD(nsc);
    305  1.1  bjh21 
    306  1.1  bjh21 	/* Does copy wrap to lower addr in ring buffer? */
    307  1.1  bjh21 	if (src + amount > sc->mem_end) {
    308  1.1  bjh21 		tmp_amount = sc->mem_end - src;
    309  1.1  bjh21 
    310  1.1  bjh21 		/* Copy amount up to end of NIC memory. */
    311  1.1  bjh21 		mx98905_readmem(nict, nich, asict, asich, src,
    312  1.1  bjh21 		    (u_int8_t *)dst, tmp_amount, useword);
    313  1.1  bjh21 
    314  1.1  bjh21 		amount -= tmp_amount;
    315  1.1  bjh21 		src = sc->mem_ring;
    316  1.1  bjh21 		dst += tmp_amount;
    317  1.1  bjh21 	}
    318  1.1  bjh21 
    319  1.1  bjh21 	mx98905_readmem(nict, nich, asict, asich, src, (u_int8_t *)dst,
    320  1.1  bjh21 	    amount, useword);
    321  1.1  bjh21 
    322  1.1  bjh21 	return (src + amount);
    323  1.1  bjh21 }
    324  1.1  bjh21 
    325  1.1  bjh21 void
    326  1.1  bjh21 mx98905_read_hdr(sc, buf, hdr)
    327  1.1  bjh21 	struct dp8390_softc *sc;
    328  1.1  bjh21 	int buf;
    329  1.1  bjh21 	struct dp8390_ring *hdr;
    330  1.1  bjh21 {
    331  1.1  bjh21 	struct ne2000_softc *nsc = (struct ne2000_softc *)sc;
    332  1.1  bjh21 
    333  1.1  bjh21 	mx98905_readmem(sc->sc_regt, sc->sc_regh, nsc->sc_asict, nsc->sc_asich,
    334  1.1  bjh21 	    buf, (u_int8_t *)hdr, sizeof(struct dp8390_ring),
    335  1.1  bjh21 	    NE2000_USE_WORD(nsc));
    336  1.1  bjh21 #if BYTE_ORDER == BIG_ENDIAN
    337  1.1  bjh21 	hdr->count = bswap16(hdr->count);
    338  1.1  bjh21 #endif
    339  1.1  bjh21 }
    340  1.1  bjh21 
    341  1.1  bjh21 static __inline void
    342  1.1  bjh21 mx98905_read_setup(bus_space_tag_t nict, bus_space_handle_t nich,
    343  1.1  bjh21     int len, int buf)
    344  1.1  bjh21 {
    345  1.1  bjh21 
    346  1.1  bjh21 	/* Select page 0 registers. */
    347  1.1  bjh21 	NIC_BARRIER(nict, nich);
    348  1.1  bjh21 	bus_space_write_1(nict, nich, ED_P0_CR,
    349  1.1  bjh21 	    ED_CR_RD2 | ED_CR_PAGE_0 | ED_CR_STA);
    350  1.1  bjh21 	NIC_BARRIER(nict, nich);
    351  1.1  bjh21 
    352  1.1  bjh21 	/* Set up DMA byte count. */
    353  1.1  bjh21 	bus_space_write_1(nict, nich, ED_P0_RBCR0, len);
    354  1.1  bjh21 	bus_space_write_1(nict, nich, ED_P0_RBCR1, len >> 8);
    355  1.1  bjh21 
    356  1.1  bjh21 	/* Set up source address in NIC mem. */
    357  1.1  bjh21 	bus_space_write_1(nict, nich, ED_P0_RSAR0, buf);
    358  1.1  bjh21 	bus_space_write_1(nict, nich, ED_P0_RSAR1, buf >> 8);
    359  1.1  bjh21 
    360  1.1  bjh21 	NIC_BARRIER(nict, nich);
    361  1.1  bjh21 	bus_space_write_1(nict, nich, ED_P0_CR,
    362  1.1  bjh21 	    ED_CR_RD0 | ED_CR_PAGE_0 | ED_CR_STA);
    363  1.1  bjh21 
    364  1.1  bjh21 	bus_space_barrier(nict, nich, 0, NE2000_NPORTS,
    365  1.1  bjh21 			  BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE);
    366  1.1  bjh21 }
    367  1.1  bjh21 
    368  1.1  bjh21 /*
    369  1.1  bjh21  * Given a NIC memory source address and a host memory destination address,
    370  1.1  bjh21  * copy 'amount' from NIC to host using programmed i/o.  The 'amount' is
    371  1.1  bjh21  * rounded up to a word - ok as long as mbufs are word sized.
    372  1.1  bjh21  */
    373  1.1  bjh21 void
    374  1.1  bjh21 mx98905_readmem(nict, nich, asict, asich, src, dst, amount, useword)
    375  1.1  bjh21 	bus_space_tag_t nict;
    376  1.1  bjh21 	bus_space_handle_t nich;
    377  1.1  bjh21 	bus_space_tag_t asict;
    378  1.1  bjh21 	bus_space_handle_t asich;
    379  1.1  bjh21 	int src;
    380  1.1  bjh21 	u_int8_t *dst;
    381  1.1  bjh21 	size_t amount;
    382  1.1  bjh21 	int useword;
    383  1.1  bjh21 {
    384  1.1  bjh21 	int len, resid;
    385  1.1  bjh21 
    386  1.1  bjh21 	resid = amount;
    387  1.1  bjh21 	/* Round up to a word. */
    388  1.1  bjh21 	if (resid & 1)
    389  1.1  bjh21 		++resid;
    390  1.1  bjh21 
    391  1.1  bjh21 	while (resid > 0) {
    392  1.1  bjh21 		len = min(resid, 254);
    393  1.1  bjh21 		mx98905_read_setup(nict, nich, len, src);
    394  1.1  bjh21 		if (useword)
    395  1.1  bjh21 			bus_space_read_multi_stream_2(asict, asich,
    396  1.1  bjh21 			    NE2000_ASIC_DATA, (u_int16_t *)dst, len >> 1);
    397  1.1  bjh21 		else
    398  1.1  bjh21 			bus_space_read_multi_1(asict, asich, NE2000_ASIC_DATA,
    399  1.1  bjh21 			    dst, len);
    400  1.1  bjh21 		resid -= len;
    401  1.1  bjh21 		src += len;
    402  1.1  bjh21 		dst += len;
    403  1.1  bjh21 	}
    404  1.1  bjh21 }
    405