// SPDX-License-Identifier: GPL-2.0+
/*
* 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>
*/
#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>
#define TSTCNTL 20
#define TSTCNTL_READ BIT(15)
#define TSTCNTL_WRITE BIT(14)
#define TSTCNTL_REG_BANK_SEL GENMASK(12, 11)
#define TSTCNTL_TEST_MODE BIT(10)
#define TSTCNTL_READ_ADDRESS GENMASK(9, 5)
#define TSTCNTL_WRITE_ADDRESS GENMASK(4, 0)
#define TSTREAD1 21
#define TSTWRITE 23
#define INTSRC_FLAG 29
#define INTSRC_ANEG_PR BIT(1)
#define INTSRC_PARALLEL_FAULT BIT(2)
#define INTSRC_ANEG_LP_ACK BIT(3)
#define INTSRC_LINK_DOWN BIT(4)
#define INTSRC_REMOTE_FAULT BIT(5)
#define INTSRC_ANEG_COMPLETE BIT(6)
#define INTSRC_MASK 30
#define BANK_ANALOG_DSP 0
#define BANK_WOL 1
#define BANK_BIST 3
/* WOL Registers */
#define LPI_STATUS 0xc
#define LPI_STATUS_RSV12 BIT(12)
/* BIST Registers */
#define FR_PLL_CONTROL 0x1b
#define FR_PLL_DIV0 0x1c
#define FR_PLL_DIV1 0x1d
static int meson_gxl_open_banks(struct phy_device *phydev)
{
int ret;
/* Enable Analog and DSP register Bank access by
* toggling TSTCNTL_TEST_MODE bit in the TSTCNTL register
*/
ret = phy_write(phydev, TSTCNTL, 0);
if (ret)
return ret;
ret = phy_write(phydev, TSTCNTL, TSTCNTL_TEST_MODE);
if (ret)
return ret;
ret = phy_write(phydev, TSTCNTL, 0);
if (ret)
return ret;
return phy_write(phydev, TSTCNTL, TSTCNTL_TEST_MODE);
}
static void meson_gxl_close_banks(struct phy_device *phydev)
{
phy_write(phydev, TSTCNTL, 0);
}
static int meson_gxl_read_reg(struct phy_device *phydev,
unsigned int bank, unsigned int reg)
{
int ret;
ret = meson_gxl_open_banks(phydev);
if (ret)
goto out;
ret = phy_write(phydev, TSTCNTL, TSTCNTL_READ |
FIELD_PREP(TSTCNTL_REG_BANK_SEL, bank) |
TSTCNTL_TEST_MODE |
FIELD_PREP(TSTCNTL_READ_ADDRESS, reg));
if (ret)
goto out;
ret = phy_read(phydev, TSTREAD1);
out:
/* Close the bank access on our way out */
meson_gxl_close_banks(phydev);
return ret;
}
static int meson_gxl_write_reg(struct phy_device *phydev,
unsigned int bank, unsigned int reg,
uint16_t value)
{
int ret;
ret = meson_gxl_open_banks(phydev);
if (ret)
goto out;
ret = phy_write(phydev, TSTWRITE, value);
if (ret)
goto out;
ret = phy_write(phydev, TSTCNTL, TSTCNTL_WRITE |
FIELD_PREP(TSTCNTL_REG_BANK_SEL, bank) |
TSTCNTL_TEST_MODE |
FIELD_PREP(TSTCNTL_WRITE_ADDRESS, reg));
out:
/* Close the bank access on our way out */
meson_gxl_close_banks(phydev);
return ret;
}
static int meson_gxl_config_init(struct phy_device *phydev)
{
int ret;
/* Enable fractional PLL */
ret = meson_gxl_write_reg(phydev, BANK_BIST, FR_PLL_CONTROL, 0x5);
if (ret)
return ret;
/* Program fraction FR_PLL_DIV1 */
ret = meson_gxl_write_reg(phydev, BANK_BIST, FR_PLL_DIV1, 0x029a);
if (ret)
return ret;
/* Program fraction FR_PLL_DIV1 */
ret = meson_gxl_write_reg(phydev, BANK_BIST, FR_PLL_DIV0, 0xaaaa);
if (ret)
return ret;
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;
/* Aneg is done, let's check everything is fine */
wol = meson_gxl_read_reg(phydev, BANK_WOL, LPI_STATUS);
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 & LPI_STATUS_RSV12) ||
((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 int meson_gxl_ack_interrupt(struct phy_device *phydev)
{
int ret = phy_read(phydev, INTSRC_FLAG);
return ret < 0 ? ret : 0;
}
static int meson_gxl_config_intr(struct phy_device *phydev)
{
u16 val;
int ret;
if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
val = INTSRC_ANEG_PR
| INTSRC_PARALLEL_FAULT
| INTSRC_ANEG_LP_ACK
| INTSRC_LINK_DOWN
| INTSRC_REMOTE_FAULT
| INTSRC_ANEG_COMPLETE;
} else {
val = 0;
}
/* Ack any pending IRQ */
ret = meson_gxl_ack_interrupt(phydev);
if (ret)
return ret;
return phy_write(phydev, INTSRC_MASK, val);
}
static struct phy_driver meson_gxl_phy[] = {
{
PHY_ID_MATCH_EXACT(0x01814400),
.name = "Meson GXL Internal PHY",
/* PHY_BASIC_FEATURES */
.flags = PHY_IS_INTERNAL,
.soft_reset = genphy_soft_reset,
.config_init = meson_gxl_config_init,
.read_status = meson_gxl_read_status,
.ack_interrupt = meson_gxl_ack_interrupt,
.config_intr = meson_gxl_config_intr,
.suspend = genphy_suspend,
.resume = genphy_resume,
}, {
PHY_ID_MATCH_EXACT(0x01803301),
.name = "Meson G12A Internal PHY",
/* PHY_BASIC_FEATURES */
.flags = PHY_IS_INTERNAL,
.soft_reset = genphy_soft_reset,
.ack_interrupt = meson_gxl_ack_interrupt,
.config_intr = meson_gxl_config_intr,
.suspend = genphy_suspend,
.resume = genphy_resume,
},
};
static struct mdio_device_id __maybe_unused meson_gxl_tbl[] = {
{ PHY_ID_MATCH_VENDOR(0x01814400) },
{ PHY_ID_MATCH_VENDOR(0x01803301) },
{ }
};
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_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
MODULE_LICENSE("GPL");