u-boot/drivers/net/phy/meson-gxl.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Meson GXL Internal PHY Driver
*
* Copyright (C) 2015 Amlogic, Inc. All rights reserved.
* Copyright (C) 2016 BayLibre, SAS. All rights reserved.
* Author: Neil Armstrong <narmstrong@baylibre.com>
*/
#include <config.h>
#include <common.h>
#include <linux/bitops.h>
#include <dm.h>
#include <phy.h>
/* This function is provided to cope with the possible failures of this phy
* during aneg process. When aneg fails, the PHY reports that aneg is done
* but the value found in MII_LPA is wrong:
* - Early failures: MII_LPA is just 0x0001. if MII_EXPANSION reports that
* the link partner (LP) supports aneg but the LP never acked our base
* code word, it is likely that we never sent it to begin with.
* - Late failures: MII_LPA is filled with a value which seems to make sense
* but it actually is not what the LP is advertising. It seems that we
* can detect this using a magic bit in the WOL bank (reg 12 - bit 12).
* If this particular bit is not set when aneg is reported being done,
* it means MII_LPA is likely to be wrong.
*
* In both case, forcing a restart of the aneg process solve the problem.
* When this failure happens, the first retry is usually successful but,
* in some cases, it may take up to 6 retries to get a decent result
*/
int meson_gxl_startup(struct phy_device *phydev)
{
unsigned int retries = 10;
int ret, wol, lpa, exp;
restart_aneg:
ret = genphy_update_link(phydev);
if (ret)
return ret;
if (phydev->autoneg == AUTONEG_ENABLE) {
/* Need to access WOL bank, make sure the access is open */
ret = phy_write(phydev, MDIO_DEVAD_NONE, 0x14, 0x0000);
if (ret)
return ret;
ret = phy_write(phydev, MDIO_DEVAD_NONE, 0x14, 0x0400);
if (ret)
return ret;
ret = phy_write(phydev, MDIO_DEVAD_NONE, 0x14, 0x0000);
if (ret)
return ret;
ret = phy_write(phydev, MDIO_DEVAD_NONE, 0x14, 0x0400);
if (ret)
return ret;
/* Request LPI_STATUS WOL register */
ret = phy_write(phydev, MDIO_DEVAD_NONE, 0x14, 0x8D80);
if (ret)
return ret;
/* Read LPI_STATUS value */
wol = phy_read(phydev, MDIO_DEVAD_NONE, 0x15);
if (wol < 0)
return wol;
lpa = phy_read(phydev, MDIO_DEVAD_NONE, MII_LPA);
if (lpa < 0)
return lpa;
exp = phy_read(phydev, MDIO_DEVAD_NONE, MII_EXPANSION);
if (exp < 0)
return exp;
if (!(wol & BIT(12)) ||
((exp & EXPANSION_NWAY) && !(lpa & LPA_LPACK))) {
/* Looks like aneg failed after all */
if (!retries) {
printf("%s LPA corruption max attempts\n",
phydev->dev->name);
return -ETIMEDOUT;
}
printf("%s LPA corruption - aneg restart\n",
phydev->dev->name);
ret = genphy_restart_aneg(phydev);
if (ret)
return ret;
--retries;
goto restart_aneg;
}
}
return genphy_parse_link(phydev);
}
static int meson_gxl_phy_config(struct phy_device *phydev)
{
/* Enable Analog and DSP register Bank access by */
phy_write(phydev, MDIO_DEVAD_NONE, 0x14, 0x0000);
phy_write(phydev, MDIO_DEVAD_NONE, 0x14, 0x0400);
phy_write(phydev, MDIO_DEVAD_NONE, 0x14, 0x0000);
phy_write(phydev, MDIO_DEVAD_NONE, 0x14, 0x0400);
/* Write Analog register 23 */
phy_write(phydev, MDIO_DEVAD_NONE, 0x17, 0x8E0D);
phy_write(phydev, MDIO_DEVAD_NONE, 0x14, 0x4417);
/* Enable fractional PLL */
phy_write(phydev, MDIO_DEVAD_NONE, 0x17, 0x0005);
phy_write(phydev, MDIO_DEVAD_NONE, 0x14, 0x5C1B);
/* Program fraction FR_PLL_DIV1 */
phy_write(phydev, MDIO_DEVAD_NONE, 0x17, 0x029A);
phy_write(phydev, MDIO_DEVAD_NONE, 0x14, 0x5C1D);
/* Program fraction FR_PLL_DIV1 */
phy_write(phydev, MDIO_DEVAD_NONE, 0x17, 0xAAAA);
phy_write(phydev, MDIO_DEVAD_NONE, 0x14, 0x5C1C);
return genphy_config(phydev);
}
static struct phy_driver meson_gxl_phy_driver = {
.name = "Meson GXL Internal PHY",
.uid = 0x01814400,
.mask = 0xfffffff0,
.features = PHY_BASIC_FEATURES,
.config = &meson_gxl_phy_config,
.startup = &meson_gxl_startup,
.shutdown = &genphy_shutdown,
};
int phy_meson_gxl_init(void)
{
phy_register(&meson_gxl_phy_driver);
return 0;
}