From 871d1d6b59802adfd42fd22c82ec419bc8fd2f10 Mon Sep 17 00:00:00 2001 From: LEROY Christophe Date: Mon, 24 Sep 2012 04:00:58 +0000 Subject: [PATCH] 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: Christophe Leroy Acked-by: Richard Cochran Signed-off-by: David S. Miller --- drivers/net/phy/lxt.c | 127 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) diff --git a/drivers/net/phy/lxt.c b/drivers/net/phy/lxt.c index 6d1e3fc..ec40ba8 100644 --- a/drivers/net/phy/lxt.c +++ b/drivers/net/phy/lxt.c @@ -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); @@ -175,6 +292,16 @@ static struct phy_driver lxt97x_driver[] = { .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", .phy_id_mask = 0xfffffff0, .features = PHY_BASIC_FEATURES, -- 2.7.4