FreeBSD/Linux Kernel Cross Reference
sys/dev/isa/elink.c

     /*      $OpenBSD: elink.c,v 1.7 2007/06/29 15:17:02 jasper Exp $        */
     /*      $NetBSD: elink.c,v 1.9 1996/05/03 19:06:27 christos Exp $       */
     
     /*
      * Copyright (c) 1996 Jason R. Thorpe.  All rights reserved.
      * Copyright (c) 1994, 1995 Charles Hannum.  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.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by Charles Hannum.
     * 4. The name of the author may not be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
     */
    
    /*
     * Common code for dealing with 3COM ethernet cards.
     */
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/malloc.h>
    #include <sys/queue.h>
    
    #include <machine/bus.h>
    
    #include <dev/isa/elink.h>
    
    /*
     * This list keeps track of which ISAs have gotten an elink_reset().
     */
    struct elink_done_reset {
            LIST_ENTRY(elink_done_reset)    er_link;
            int                             er_bus;
    };
    static LIST_HEAD(, elink_done_reset) elink_all_resets;
    static int elink_all_resets_initialized;
    
    /*
     * Issue a `global reset' to all cards, and reset the ID state machines.  We
     * have to be careful to do the global reset only once during autoconfig, to
     * prevent resetting boards that have already been configured.
     *
     * The "bus" argument here is the unit number of the ISA bus, e.g. ""
     * if the bus is "isa0".
     *
     * NOTE: the caller MUST provide an i/o handle for ELINK_ID_PORT!
     */
    void
    elink_reset(bus_space_tag_t iot, bus_space_handle_t ioh, int bus)
    {
            struct elink_done_reset *er;
    
            if (elink_all_resets_initialized == 0) {
                    LIST_INIT(&elink_all_resets);
                    elink_all_resets_initialized = 1;
            }
    
            /*
             * Reset these cards if we haven't done so already.
             */
            LIST_FOREACH(er, &elink_all_resets, er_link)
                    if (er->er_bus == bus)
                            goto out;
    
            /* Mark this bus so we don't do it again. */
            er = (struct elink_done_reset *)malloc(sizeof(struct elink_done_reset),
                M_DEVBUF, M_NOWAIT);
            if (er == NULL)
                    panic("elink_reset: can't allocate state storage");
    
            er->er_bus = bus;
            LIST_INSERT_HEAD(&elink_all_resets, er, er_link);
    
            /* Haven't reset the cards on this bus, yet. */
            bus_space_write_1(iot, ioh, 0, ELINK_RESET);
    
     out:
            bus_space_write_1(iot, ioh, 0, 0x00);
            bus_space_write_1(iot, ioh, 0, 0x00);
    }
   
   /*
    * The `ID sequence' is really just snapshots of an 8-bit CRC register as 0
    * bits are shifted in.  Different board types use different polynomials.
    *
    * NOTE: the caller MUST provide an i/o handle for ELINK_ID_PORT!
    */
   void
   elink_idseq(bus_space_tag_t iot, bus_space_handle_t ioh, u_char p)
   {
           int i;
           u_char c;
   
           c = 0xff;
           for (i = 255; i; i--) {
                   bus_space_write_1(iot, ioh, 0, c);
                   if (c & 0x80) {
                           c <<= 1;
                           c ^= p;
                   } else
                           c <<= 1;
           }
   }

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