src/net/mii.c

   1 /*
   2
   3         mii.c: MII interface library
   4
   5         Ported to gPXE by Daniel Verkamp <daniel@drv.nu>
   6         from Linux drivers/net/mii.c
   7
   8         Maintained by Jeff Garzik <jgarzik@pobox.com>
   9         Copyright 2001,2002 Jeff Garzik
  10
  11         Various code came from myson803.c and other files by
  12         Donald Becker.  Copyright:
  13
  14                 Written 1998-2002 by Donald Becker.
  15
  16                 This software may be used and distributed according
  17                 to the terms of the GNU General Public License (GPL),
  18                 incorporated herein by reference.  Drivers based on
  19                 or derived from this code fall under the GPL and must
  20                 retain the authorship, copyright and license notice.
  21                 This file is not a complete program and may only be
  22                 used when the entire operating system is licensed
  23                 under the GPL.
  24
  25                 The author may be reached as becker@scyld.com, or C/O
  26                 Scyld Computing Corporation
  27                 410 Severn Ave., Suite 210
  28                 Annapolis MD 21403
  29
  30 */
  31
  32 #include <mii.h>
  33
  34 /**
  35  * mii_link_ok - is link status up/ok
  36  * @mii: the MII interface
  37  *
  38  * Returns 1 if the MII reports link status up/ok, 0 otherwise.
  39  */
  40 int
  41 mii_link_ok ( struct mii_if_info *mii )
  42 {
  43         /* first, a dummy read, needed to latch some MII phys */
  44         mii->mdio_read ( mii->dev, mii->phy_id, MII_BMSR );
  45         if ( mii->mdio_read ( mii->dev, mii->phy_id, MII_BMSR ) & BMSR_LSTATUS )
  46                 return 1;
  47         return 0;
  48 }
  49
  50 /**
  51  * mii_check_link - check MII link status
  52  * @mii: MII interface
  53  *
  54  * If the link status changed (previous != current), call
  55  * netif_carrier_on() if current link status is Up or call
  56  * netif_carrier_off() if current link status is Down.
  57  */
  58 void
  59 mii_check_link ( struct mii_if_info *mii )
  60 {
  61         int cur_link = mii_link_ok ( mii );
  62         int prev_link = netdev_link_ok ( mii->dev );
  63
  64         if ( cur_link && !prev_link )
  65                 netdev_link_up ( mii->dev );
  66         else if (prev_link && !cur_link)
  67                 netdev_link_down ( mii->dev );
  68 }
  69
  70
  71 /**
  72  * mii_check_media - check the MII interface for a duplex change
  73  * @mii: the MII interface
  74  * @ok_to_print: OK to print link up/down messages
  75  * @init_media: OK to save duplex mode in @mii
  76  *
  77  * Returns 1 if the duplex mode changed, 0 if not.
  78  * If the media type is forced, always returns 0.
  79  */
  80 unsigned int
  81 mii_check_media ( struct mii_if_info *mii,
  82                   unsigned int ok_to_print,
  83                   unsigned int init_media )
  84 {
  85         unsigned int old_carrier, new_carrier;
  86         int advertise, lpa, media, duplex;
  87         int lpa2 = 0;
  88
  89         /* if forced media, go no further */
  90         if (mii->force_media)
  91                 return 0; /* duplex did not change */
  92
  93         /* check current and old link status */
  94         old_carrier = netdev_link_ok ( mii->dev ) ? 1 : 0;
  95         new_carrier = (unsigned int) mii_link_ok ( mii );
  96
  97         /* if carrier state did not change, this is a "bounce",
  98          * just exit as everything is already set correctly
  99          */
 100         if ( ( ! init_media ) && ( old_carrier == new_carrier ) )
 101                 return 0; /* duplex did not change */
 102
 103         /* no carrier, nothing much to do */
 104         if ( ! new_carrier ) {
 105                 netdev_link_down ( mii->dev );
 106                 if ( ok_to_print )
 107                         DBG ( "%s: link down\n", mii->dev->name);
 108                 return 0; /* duplex did not change */
 109         }
 110
 111         /*
 112          * we have carrier, see who's on the other end
 113          */
 114         netdev_link_up ( mii->dev );
 115
 116         /* get MII advertise and LPA values */
 117         if ( ( ! init_media ) && ( mii->advertising ) ) {
 118                 advertise = mii->advertising;
 119         } else {
 120                 advertise = mii->mdio_read ( mii->dev, mii->phy_id, MII_ADVERTISE );
 121                 mii->advertising = advertise;
 122         }
 123         lpa = mii->mdio_read ( mii->dev, mii->phy_id, MII_LPA );
 124         if ( mii->supports_gmii )
 125                 lpa2 = mii->mdio_read ( mii->dev, mii->phy_id, MII_STAT1000 );
 126
 127         /* figure out media and duplex from advertise and LPA values */
 128         media = mii_nway_result ( lpa & advertise );
 129         duplex = ( media & ADVERTISE_FULL ) ? 1 : 0;
 130         if ( lpa2 & LPA_1000FULL )
 131                 duplex = 1;
 132
 133         if ( ok_to_print )
 134                 DBG ( "%s: link up, %sMbps, %s-duplex, lpa 0x%04X\n",
 135                        mii->dev->name,
 136                        lpa2 & ( LPA_1000FULL | LPA_1000HALF ) ? "1000" :
 137                        media & ( ADVERTISE_100FULL | ADVERTISE_100HALF ) ? "100" : "10",
 138                        duplex ? "full" : "half",
 139                        lpa);
 140
 141         if ( ( init_media ) || ( mii->full_duplex != duplex ) ) {
 142                 mii->full_duplex = duplex;
 143                 return 1; /* duplex changed */
 144         }
 145
 146         return 0; /* duplex did not change */
 147 }