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Commit 871d1d6b authored by LEROY Christophe's avatar LEROY Christophe Committed by David S. Miller
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lxt PHY: Support for the buggy LXT973 rev A2 



This patch adds proper handling of the buggy revision A2 of LXT973 phy, adding
precautions linked to ERRATA Item 4:

Revision A2 of LXT973 chip randomly returns the contents of the previous even
register when you read a odd register regularly

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Acked-by: default avatarRichard Cochran <richardcochran@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 26f7cbc0

drivers/net/phy/lxt.c

+127 −0
Original line number Diff line number Diff line
@@ -122,6 +122,123 @@ static int lxt971_config_intr(struct phy_device *phydev) 
	return err;

}



/*

 * A2 version of LXT973 chip has an ERRATA: it randomly return the contents

 * of the previous even register when you read a odd register regularly

 */



static int lxt973a2_update_link(struct phy_device *phydev)

{

	int status;

	int control;

	int retry = 8; /* we try 8 times */



	/* Do a fake read */

	status = phy_read(phydev, MII_BMSR);



	if (status < 0)

		return status;



	control = phy_read(phydev, MII_BMCR);

	if (control < 0)

		return control;



	do {

		/* Read link and autonegotiation status */

		status = phy_read(phydev, MII_BMSR);

	} while (status >= 0 && retry-- && status == control);



	if (status < 0)

		return status;



	if ((status & BMSR_LSTATUS) == 0)

		phydev->link = 0;

	else

		phydev->link = 1;



	return 0;

}



int lxt973a2_read_status(struct phy_device *phydev)

{

	int adv;

	int err;

	int lpa;

	int lpagb = 0;



	/* Update the link, but return if there was an error */

	err = lxt973a2_update_link(phydev);

	if (err)

		return err;



	if (AUTONEG_ENABLE == phydev->autoneg) {

		int retry = 1;



		adv = phy_read(phydev, MII_ADVERTISE);



		if (adv < 0)

			return adv;



		do {

			lpa = phy_read(phydev, MII_LPA);



			if (lpa < 0)

				return lpa;



			/* If both registers are equal, it is suspect but not

			* impossible, hence a new try

			*/

		} while (lpa == adv && retry--);



		lpa &= adv;



		phydev->speed = SPEED_10;

		phydev->duplex = DUPLEX_HALF;

		phydev->pause = phydev->asym_pause = 0;



		if (lpagb & (LPA_1000FULL | LPA_1000HALF)) {

			phydev->speed = SPEED_1000;



			if (lpagb & LPA_1000FULL)

				phydev->duplex = DUPLEX_FULL;

		} else if (lpa & (LPA_100FULL | LPA_100HALF)) {

			phydev->speed = SPEED_100;



			if (lpa & LPA_100FULL)

				phydev->duplex = DUPLEX_FULL;

		} else {

			if (lpa & LPA_10FULL)

				phydev->duplex = DUPLEX_FULL;

		}



		if (phydev->duplex == DUPLEX_FULL) {

			phydev->pause = lpa & LPA_PAUSE_CAP ? 1 : 0;

			phydev->asym_pause = lpa & LPA_PAUSE_ASYM ? 1 : 0;

		}

	} else {

		int bmcr = phy_read(phydev, MII_BMCR);



		if (bmcr < 0)

			return bmcr;



		if (bmcr & BMCR_FULLDPLX)

			phydev->duplex = DUPLEX_FULL;

		else

			phydev->duplex = DUPLEX_HALF;



		if (bmcr & BMCR_SPEED1000)

			phydev->speed = SPEED_1000;

		else if (bmcr & BMCR_SPEED100)

			phydev->speed = SPEED_100;

		else

			phydev->speed = SPEED_10;



		phydev->pause = phydev->asym_pause = 0;

	}



	return 0;

}



static int lxt973_probe(struct phy_device *phydev)

{

	int val = phy_read(phydev, MII_LXT973_PCR);
@@ -173,6 +290,16 @@ static struct phy_driver lxt97x_driver[] = { 
	.ack_interrupt	= lxt971_ack_interrupt,

	.config_intr	= lxt971_config_intr,

	.driver		= { .owner = THIS_MODULE,},

}, {

	.phy_id		= 0x00137a10,

	.name		= "LXT973-A2",

	.phy_id_mask	= 0xffffffff,

	.features	= PHY_BASIC_FEATURES,

	.flags		= 0,

	.probe		= lxt973_probe,

	.config_aneg	= lxt973_config_aneg,

	.read_status	= lxt973a2_read_status,

	.driver		= { .owner = THIS_MODULE,},

}, {

	.phy_id		= 0x00137a10,

	.name		= "LXT973",