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/*
* Amlogic 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>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/phy.h>
#include <linux/netdevice.h>
#include <linux/bitfield.h>
static int meson_gxl_config_init(struct phy_device *phydev)
{
/* Enable Analog and DSP register Bank access by */
phy_write(phydev, 0x14, 0x0000);
phy_write(phydev, 0x14, 0x0400);
phy_write(phydev, 0x14, 0x0000);
phy_write(phydev, 0x14, 0x0400);
/* Write Analog register 23 */
phy_write(phydev, 0x17, 0x8E0D);
phy_write(phydev, 0x14, 0x4417);
/* Enable fractional PLL */
phy_write(phydev, 0x17, 0x0005);
phy_write(phydev, 0x14, 0x5C1B);
/* Program fraction FR_PLL_DIV1 */
phy_write(phydev, 0x17, 0x029A);
phy_write(phydev, 0x14, 0x5C1D);
/* Program fraction FR_PLL_DIV1 */
phy_write(phydev, 0x17, 0xAAAA);
phy_write(phydev, 0x14, 0x5C1C);
return 0;
}
/* 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
*/
static int meson_gxl_read_status(struct phy_device *phydev)
{
int ret, wol, lpa, exp;
if (phydev->autoneg == AUTONEG_ENABLE) {
ret = genphy_aneg_done(phydev);
if (ret < 0)
return ret;
else if (!ret)
goto read_status_continue;
/* Need to access WOL bank, make sure the access is open */
ret = phy_write(phydev, 0x14, 0x0000);
if (ret)
return ret;
ret = phy_write(phydev, 0x14, 0x0400);
if (ret)
return ret;
ret = phy_write(phydev, 0x14, 0x0000);
if (ret)
return ret;
ret = phy_write(phydev, 0x14, 0x0400);
if (ret)
return ret;
/* Request LPI_STATUS WOL register */
ret = phy_write(phydev, 0x14, 0x8D80);
if (ret)
return ret;
/* Read LPI_STATUS value */
wol = phy_read(phydev, 0x15);
if (wol < 0)
return wol;
lpa = phy_read(phydev, MII_LPA);
if (lpa < 0)
return lpa;
exp = phy_read(phydev, MII_EXPANSION);
if (exp < 0)
return exp;
if (!(wol & BIT(12)) ||
((exp & EXPANSION_NWAY) && !(lpa & LPA_LPACK))) {
/* Looks like aneg failed after all */
phydev_dbg(phydev, "LPA corruption - aneg restart\n");
return genphy_restart_aneg(phydev);
}
}
read_status_continue:
return genphy_read_status(phydev);
}
static struct phy_driver meson_gxl_phy[] = {
{
.phy_id = 0x01814400,
.phy_id_mask = 0xfffffff0,
.name = "Meson GXL Internal PHY",
.features = PHY_BASIC_FEATURES,
.flags = PHY_IS_INTERNAL,
.config_init = meson_gxl_config_init,
.config_aneg = genphy_config_aneg,
.aneg_done = genphy_aneg_done,
.read_status = meson_gxl_read_status,
.suspend = genphy_suspend,
.resume = genphy_resume,
},
};
static struct mdio_device_id __maybe_unused meson_gxl_tbl[] = {
{ 0x01814400, 0xfffffff0 },
{ }
};
module_phy_driver(meson_gxl_phy);
MODULE_DEVICE_TABLE(mdio, meson_gxl_tbl);
MODULE_DESCRIPTION("Amlogic Meson GXL Internal PHY driver");
MODULE_AUTHOR("Baoqi wang");
MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
MODULE_LICENSE("GPL");