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 */
40int
41mii_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 */
58void
59mii_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 */
80unsigned int
81mii_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}
148