sys/dev/isa/elink.c

   1 /*      $NetBSD: elink.c,v 1.16 2008/04/28 20:23:52 martin Exp $        */
   2
   3 /*-
   4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Jason R. Thorpe and Charles M. Hannum.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * Common code for dealing with 3COM ethernet cards.
  34  */
  35
  36 #include <sys/cdefs.h>
  37 __KERNEL_RCSID(0, "$NetBSD: elink.c,v 1.16 2008/04/28 20:23:52 martin Exp $");
  38
  39 #include <sys/param.h>
  40 #include <sys/systm.h>
  41 #include <sys/malloc.h>
  42 #include <sys/queue.h>
  43
  44 #include <sys/bus.h>
  45
  46 #include <dev/isa/elink.h>
  47
  48 /*
  49  * This list keeps track of which ISAs have gotten an elink_reset().
  50  */
  51 struct elink_done_reset {
  52         LIST_ENTRY(elink_done_reset)    er_link;
  53         int                             er_bus;
  54 };
  55 static LIST_HEAD(, elink_done_reset) elink_all_resets;
  56 static int elink_all_resets_initialized;
  57
  58 /*
  59  * Issue a `global reset' to all cards, and reset the ID state machines.  We
  60  * have to be careful to do the global reset only once during autoconfig, to
  61  * prevent resetting boards that have already been configured.
  62  *
  63  * The "bus" argument here is the unit number of the ISA bus, e.g. "0"
  64  * if the bus is "isa0".
  65  *
  66  * NOTE: the caller MUST provide an access handle for ELINK_ID_PORT!
  67  */
  68 void
  69 elink_reset(bus_space_tag_t iot, bus_space_handle_t ioh, int bus)
  70 {
  71         struct elink_done_reset *er;
  72
  73         if (elink_all_resets_initialized == 0) {
  74                 LIST_INIT(&elink_all_resets);
  75                 elink_all_resets_initialized = 1;
  76         }
  77
  78         /*
  79          * Reset these cards if we haven't done so already.
  80          */
  81         for (er = elink_all_resets.lh_first; er != NULL;
  82             er = er->er_link.le_next)
  83                 if (er->er_bus == bus)
  84                         goto out;
  85
  86         /* Mark this bus so we don't do it again. */
  87         er = (struct elink_done_reset *)malloc(sizeof(struct elink_done_reset),
  88             M_DEVBUF, M_NOWAIT);
  89         if (er == NULL)
  90                 panic("elink_reset: can't allocate state storage");
  91
  92         er->er_bus = bus;
  93         LIST_INSERT_HEAD(&elink_all_resets, er, er_link);
  94
  95         /* Haven't reset the cards on this bus, yet. */
  96         bus_space_write_1(iot, ioh, 0, ELINK_RESET);
  97
  98  out:
  99         bus_space_write_1(iot, ioh, 0, 0x00);
 100         bus_space_write_1(iot, ioh, 0, 0x00);
 101 }
 102
 103 /*
 104  * The `ID sequence' is really just snapshots of an 8-bit CRC register as 0
 105  * bits are shifted in.  Different board types use different polynomials.
 106  *
 107  * NOTE: the caller MUST provide an access handle for ELINK_ID_PORT!
 108  */
 109 void
 110 elink_idseq(bus_space_tag_t iot, bus_space_handle_t ioh, u_char p)
 111 {
 112         int i;
 113         u_char c;
 114
 115         c = 0xff;
 116         for (i = 255; i; i--) {
 117                 bus_space_write_1(iot, ioh, 0, c);
 118                 if (c & 0x80) {
 119                         c <<= 1;
 120                         c ^= p;
 121                 } else
 122                         c <<= 1;
 123         }
 124 }