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// SPDX-License-Identifier: GPL-2.0
// Broadcom BCM84881 NBASE-T PHY driver, as found on a SFP+ module.
// Copyright (C) 2019 Russell King, Deep Blue Solutions Ltd.
//
// Like the Marvell 88x3310, the Broadcom 84881 changes its host-side
// interface according to the operating speed between 10GBASE-R,
// 2500BASE-X and SGMII (but unlike the 88x3310, without the control
// word).
//
// This driver only supports those aspects of the PHY that I'm able to
// observe and test with the SFP+ module, which is an incomplete subset
// of what this PHY is able to support. For example, I only assume it
// supports a single lane Serdes connection, but it may be that the PHY
// is able to support more than that.
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/phy.h>
enum {
MDIO_AN_C22 = 0xffe0,
};
static int bcm84881_wait_init(struct phy_device *phydev)
{
unsigned int tries = 20;
int ret, val;
do {
val = phy_read_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_CTRL1);
if (val < 0) {
ret = val;
break;
}
if (!(val & MDIO_CTRL1_RESET)) {
ret = 0;
break;
}
if (!--tries) {
ret = -ETIMEDOUT;
break;
}
msleep(100);
} while (1);
if (ret)
phydev_err(phydev, "%s failed: %d\n", __func__, ret);
return ret;
}
static int bcm84881_config_init(struct phy_device *phydev)
{
switch (phydev->interface) {
case PHY_INTERFACE_MODE_SGMII:
case PHY_INTERFACE_MODE_2500BASEX:
case PHY_INTERFACE_MODE_10GBASER:
break;
default:
return -ENODEV;
}
return 0;
}
static int bcm84881_probe(struct phy_device *phydev)
{
/* This driver requires PMAPMD and AN blocks */
const u32 mmd_mask = MDIO_DEVS_PMAPMD | MDIO_DEVS_AN;
if (!phydev->is_c45 ||
(phydev->c45_ids.devices_in_package & mmd_mask) != mmd_mask)
return -ENODEV;
return 0;
}
static int bcm84881_get_features(struct phy_device *phydev)
{
int ret;
ret = genphy_c45_pma_read_abilities(phydev);
if (ret)
return ret;
/* Although the PHY sets bit 1.11.8, it does not support 10M modes */
linkmode_clear_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT,
phydev->supported);
linkmode_clear_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT,
phydev->supported);
return 0;
}
static int bcm84881_config_aneg(struct phy_device *phydev)
{
bool changed = false;
u32 adv;
int ret;
/* Wait for the PHY to finish initialising, otherwise our
* advertisement may be overwritten.
*/
ret = bcm84881_wait_init(phydev);
if (ret)
return ret;
/* We don't support manual MDI control */
phydev->mdix_ctrl = ETH_TP_MDI_AUTO;
/* disabled autoneg doesn't seem to work with this PHY */
if (phydev->autoneg == AUTONEG_DISABLE)
return -EINVAL;
ret = genphy_c45_an_config_aneg(phydev);
if (ret < 0)
return ret;
if (ret > 0)
changed = true;
adv = linkmode_adv_to_mii_ctrl1000_t(phydev->advertising);
ret = phy_modify_mmd_changed(phydev, MDIO_MMD_AN,
MDIO_AN_C22 + MII_CTRL1000,
ADVERTISE_1000FULL | ADVERTISE_1000HALF,
adv);
if (ret < 0)
return ret;
if (ret > 0)
changed = true;
return genphy_c45_check_and_restart_aneg(phydev, changed);
}
static int bcm84881_aneg_done(struct phy_device *phydev)
{
int bmsr, val;
val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_STAT1);
if (val < 0)
return val;
bmsr = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_C22 + MII_BMSR);
if (bmsr < 0)
return val;
return !!(val & MDIO_AN_STAT1_COMPLETE) &&
!!(bmsr & BMSR_ANEGCOMPLETE);
}
static int bcm84881_read_status(struct phy_device *phydev)
{
unsigned int mode;
int bmsr, val;
val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_CTRL1);
if (val < 0)
return val;
if (val & MDIO_AN_CTRL1_RESTART) {
phydev->link = 0;
return 0;
}
val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_STAT1);
if (val < 0)
return val;
bmsr = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_C22 + MII_BMSR);
if (bmsr < 0)
return val;
phydev->autoneg_complete = !!(val & MDIO_AN_STAT1_COMPLETE) &&
!!(bmsr & BMSR_ANEGCOMPLETE);
phydev->link = !!(val & MDIO_STAT1_LSTATUS) &&
!!(bmsr & BMSR_LSTATUS);
if (phydev->autoneg == AUTONEG_ENABLE && !phydev->autoneg_complete)
phydev->link = false;
if (!phydev->link)
return 0;
linkmode_zero(phydev->lp_advertising);
phydev->speed = SPEED_UNKNOWN;
phydev->duplex = DUPLEX_UNKNOWN;
phydev->pause = 0;
phydev->asym_pause = 0;
phydev->mdix = 0;
if (phydev->autoneg_complete) {
val = genphy_c45_read_lpa(phydev);
if (val < 0)
return val;
val = phy_read_mmd(phydev, MDIO_MMD_AN,
MDIO_AN_C22 + MII_STAT1000);
if (val < 0)
return val;
mii_stat1000_mod_linkmode_lpa_t(phydev->lp_advertising, val);
if (phydev->autoneg == AUTONEG_ENABLE)
phy_resolve_aneg_linkmode(phydev);
}
if (phydev->autoneg == AUTONEG_DISABLE) {
/* disabled autoneg doesn't seem to work, so force the link
* down.
*/
phydev->link = 0;
return 0;
}
/* Set the host link mode - we set the phy interface mode and
* the speed according to this register so that downshift works.
* We leave the duplex setting as per the resolution from the
* above.
*/
val = phy_read_mmd(phydev, MDIO_MMD_VEND1, 0x4011);
mode = (val & 0x1e) >> 1;
if (mode == 1 || mode == 2)
phydev->interface = PHY_INTERFACE_MODE_SGMII;
else if (mode == 3)
phydev->interface = PHY_INTERFACE_MODE_10GBASER;
else if (mode == 4)
phydev->interface = PHY_INTERFACE_MODE_2500BASEX;
switch (mode & 7) {
case 1:
phydev->speed = SPEED_100;
break;
case 2:
phydev->speed = SPEED_1000;
break;
case 3:
phydev->speed = SPEED_10000;
break;
case 4:
phydev->speed = SPEED_2500;
break;
case 5:
phydev->speed = SPEED_5000;
break;
}
return genphy_c45_read_mdix(phydev);
}
static struct phy_driver bcm84881_drivers[] = {
{
.phy_id = 0xae025150,
.phy_id_mask = 0xfffffff0,
.name = "Broadcom BCM84881",
.config_init = bcm84881_config_init,
.probe = bcm84881_probe,
.get_features = bcm84881_get_features,
.config_aneg = bcm84881_config_aneg,
.aneg_done = bcm84881_aneg_done,
.read_status = bcm84881_read_status,
},
};
module_phy_driver(bcm84881_drivers);
/* FIXME: module auto-loading for Clause 45 PHYs seems non-functional */
static struct mdio_device_id __maybe_unused bcm84881_tbl[] = {
{ 0xae025150, 0xfffffff0 },
{ },
};
MODULE_AUTHOR("Russell King");
MODULE_DESCRIPTION("Broadcom BCM84881 PHY driver");
MODULE_DEVICE_TABLE(mdio, bcm84881_tbl);
MODULE_LICENSE("GPL");