linux-stable/drivers/net/phy/swphy.c
Heiner Kallweit 726097d6d6 net: phy: improve auto-neg emulation in swphy
Auto-neg emulation currently doesn't set bit BMCR_ANENABLE in BMCR,
add this. Users will ignore speed and duplex settings in BMCR because
we're emulating auto-neg, therefore we can remove related code.
See also following discussion [0].

[0] https://marc.info/?t=155041784900002&r=1&w=2

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-24 22:28:15 -08:00

167 lines
3.5 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Software PHY emulation
*
* Code taken from fixed_phy.c by Russell King <rmk+kernel@arm.linux.org.uk>
*
* Author: Vitaly Bordug <vbordug@ru.mvista.com>
* Anton Vorontsov <avorontsov@ru.mvista.com>
*
* Copyright (c) 2006-2007 MontaVista Software, Inc.
*/
#include <linux/export.h>
#include <linux/mii.h>
#include <linux/phy.h>
#include <linux/phy_fixed.h>
#include "swphy.h"
#define MII_REGS_NUM 29
struct swmii_regs {
u16 bmsr;
u16 lpa;
u16 lpagb;
};
enum {
SWMII_SPEED_10 = 0,
SWMII_SPEED_100,
SWMII_SPEED_1000,
SWMII_DUPLEX_HALF = 0,
SWMII_DUPLEX_FULL,
};
/*
* These two tables get bitwise-anded together to produce the final result.
* This means the speed table must contain both duplex settings, and the
* duplex table must contain all speed settings.
*/
static const struct swmii_regs speed[] = {
[SWMII_SPEED_10] = {
.lpa = LPA_10FULL | LPA_10HALF,
},
[SWMII_SPEED_100] = {
.bmsr = BMSR_100FULL | BMSR_100HALF,
.lpa = LPA_100FULL | LPA_100HALF,
},
[SWMII_SPEED_1000] = {
.bmsr = BMSR_ESTATEN,
.lpagb = LPA_1000FULL | LPA_1000HALF,
},
};
static const struct swmii_regs duplex[] = {
[SWMII_DUPLEX_HALF] = {
.bmsr = BMSR_ESTATEN | BMSR_100HALF,
.lpa = LPA_10HALF | LPA_100HALF,
.lpagb = LPA_1000HALF,
},
[SWMII_DUPLEX_FULL] = {
.bmsr = BMSR_ESTATEN | BMSR_100FULL,
.lpa = LPA_10FULL | LPA_100FULL,
.lpagb = LPA_1000FULL,
},
};
static int swphy_decode_speed(int speed)
{
switch (speed) {
case 1000:
return SWMII_SPEED_1000;
case 100:
return SWMII_SPEED_100;
case 10:
return SWMII_SPEED_10;
default:
return -EINVAL;
}
}
/**
* swphy_validate_state - validate the software phy status
* @state: software phy status
*
* This checks that we can represent the state stored in @state can be
* represented in the emulated MII registers. Returns 0 if it can,
* otherwise returns -EINVAL.
*/
int swphy_validate_state(const struct fixed_phy_status *state)
{
int err;
if (state->link) {
err = swphy_decode_speed(state->speed);
if (err < 0) {
pr_warn("swphy: unknown speed\n");
return -EINVAL;
}
}
return 0;
}
EXPORT_SYMBOL_GPL(swphy_validate_state);
/**
* swphy_read_reg - return a MII register from the fixed phy state
* @reg: MII register
* @state: fixed phy status
*
* Return the MII @reg register generated from the fixed phy state @state.
*/
int swphy_read_reg(int reg, const struct fixed_phy_status *state)
{
int speed_index, duplex_index;
u16 bmsr = BMSR_ANEGCAPABLE;
u16 lpagb = 0;
u16 lpa = 0;
if (reg > MII_REGS_NUM)
return -1;
speed_index = swphy_decode_speed(state->speed);
if (WARN_ON(speed_index < 0))
return 0;
duplex_index = state->duplex ? SWMII_DUPLEX_FULL : SWMII_DUPLEX_HALF;
bmsr |= speed[speed_index].bmsr & duplex[duplex_index].bmsr;
if (state->link) {
bmsr |= BMSR_LSTATUS | BMSR_ANEGCOMPLETE;
lpa |= speed[speed_index].lpa & duplex[duplex_index].lpa;
lpagb |= speed[speed_index].lpagb & duplex[duplex_index].lpagb;
if (state->pause)
lpa |= LPA_PAUSE_CAP;
if (state->asym_pause)
lpa |= LPA_PAUSE_ASYM;
}
switch (reg) {
case MII_BMCR:
return BMCR_ANENABLE;
case MII_BMSR:
return bmsr;
case MII_PHYSID1:
case MII_PHYSID2:
return 0;
case MII_LPA:
return lpa;
case MII_STAT1000:
return lpagb;
/*
* We do not support emulating Clause 45 over Clause 22 register
* reads. Return an error instead of bogus data.
*/
case MII_MMD_CTRL:
case MII_MMD_DATA:
return -1;
default:
return 0xffff;
}
}
EXPORT_SYMBOL_GPL(swphy_read_reg);