mirror of
https://github.com/ipxe/ipxe
synced 2026-04-16 03:00:10 +03:00
Michael Brown
6ad02e78bb
Most devices expose at least the link up/down status via a bit in a
MAC register, since the MAC generally already needs to know whether or
not the link is up. Some devices (e.g. the SMSC75xx USB NIC) expose
this information to software only via the MII registers.
Provide a generic mii_check_link() implementation to check the BMSR
and report the link status via netdev_link_{up,down}().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
150 lines
3.5 KiB
C
150 lines
3.5 KiB
C
/*
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* Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*
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* You can also choose to distribute this program under the terms of
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* the Unmodified Binary Distribution Licence (as given in the file
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* COPYING.UBDL), provided that you have satisfied its requirements.
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*/
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FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
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#include <string.h>
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#include <unistd.h>
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#include <errno.h>
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#include <ipxe/mii.h>
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/** @file
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*
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* Media Independent Interface
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*
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*/
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/**
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* Restart autonegotiation
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*
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* @v mii MII interface
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* @ret rc Return status code
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*/
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int mii_restart ( struct mii_interface *mii ) {
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int bmcr;
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int rc;
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/* Read BMCR */
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bmcr = mii_read ( mii, MII_BMCR );
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if ( bmcr < 0 ) {
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rc = bmcr;
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DBGC ( mii, "MII %p could not read BMCR: %s\n",
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mii, strerror ( rc ) );
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return rc;
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}
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/* Enable and restart autonegotiation */
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bmcr |= ( BMCR_ANENABLE | BMCR_ANRESTART );
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if ( ( rc = mii_write ( mii, MII_BMCR, bmcr ) ) != 0 ) {
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DBGC ( mii, "MII %p could not write BMCR: %s\n",
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mii, strerror ( rc ) );
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return rc;
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}
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DBGC ( mii, "MII %p restarted autonegotiation\n", mii );
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return 0;
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}
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/**
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* Reset MII interface
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*
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* @v mii MII interface
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* @ret rc Return status code
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*/
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int mii_reset ( struct mii_interface *mii ) {
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unsigned int i;
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int bmcr;
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int rc;
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/* Power-up, enable autonegotiation and initiate reset */
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if ( ( rc = mii_write ( mii, MII_BMCR,
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( BMCR_RESET | BMCR_ANENABLE ) ) ) != 0 ) {
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DBGC ( mii, "MII %p could not write BMCR: %s\n",
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mii, strerror ( rc ) );
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return rc;
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}
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/* Wait for reset to complete */
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for ( i = 0 ; i < MII_RESET_MAX_WAIT_MS ; i++ ) {
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/* Check if reset has completed */
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bmcr = mii_read ( mii, MII_BMCR );
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if ( bmcr < 0 ) {
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rc = bmcr;
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DBGC ( mii, "MII %p could not read BMCR: %s\n",
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mii, strerror ( rc ) );
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return rc;
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}
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/* If reset is not complete, delay 1ms and retry */
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if ( bmcr & BMCR_RESET ) {
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mdelay ( 1 );
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continue;
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}
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/* Force autonegotation on again, in case it was
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* cleared by the reset.
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*/
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if ( ( rc = mii_restart ( mii ) ) != 0 )
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return rc;
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DBGC ( mii, "MII %p reset after %dms\n", mii, i );
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return 0;
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}
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DBGC ( mii, "MII %p timed out waiting for reset\n", mii );
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return -ETIMEDOUT;
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}
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/**
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* Update link status via MII
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*
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* @v mii MII interface
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* @v netdev Network device
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* @ret rc Return status code
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*/
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int mii_check_link ( struct mii_interface *mii, struct net_device *netdev ) {
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int bmsr;
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int link;
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int rc;
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/* Read BMSR */
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bmsr = mii_read ( mii, MII_BMSR );
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if ( bmsr < 0 ) {
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rc = bmsr;
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return rc;
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}
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/* Report link status */
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link = ( bmsr & BMSR_LSTATUS );
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DBGC ( mii, "MII %p link %s (BMSR %#04x)\n",
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mii, ( link ? "up" : "down" ), bmsr );
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if ( link ) {
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netdev_link_up ( netdev );
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} else {
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netdev_link_down ( netdev );
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}
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return 0;
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}
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