[PATCH v2 1/2] ethtool: provide UAPI for PHY master/slave configuration.

From: Oleksij Rempel
Date: Mon Apr 20 2020 - 09:15:34 EST

This UAPI is needed for BroadR-Reach 100BASE-T1 devices. Due to lack of
auto-negotiation support, we needed to be able to configure the
MASTER-SLAVE role of the port manually or from an application in user
space.

The same UAPI can be used for 1000BASE-T or MultiGBASE-T devices to
force MASTER or SLAVE role. See IEEE 802.3-2018:
22.2.4.3.7 MASTER-SLAVE control register (Register 9)
22.2.4.3.8 MASTER-SLAVE status register (Register 10)
40.5.2 MASTER-SLAVE configuration resolution
45.2.1.185.1 MASTER-SLAVE config value (1.2100.14)
45.2.7.10 MultiGBASE-T AN control 1 register (Register 7.32)

The MASTER-SLAVE role affects the clock configuration:

-------------------------------------------------------------------------------
When the PHY is configured as MASTER, the PMA Transmit function shall
source TX_TCLK from a local clock source. When configured as SLAVE, the
PMA Transmit function shall source TX_TCLK from the clock recovered from
data stream provided by MASTER.

iMX6Q KSZ9031 XXX
------\ /-----------\ /------------\
| | | | |
MAC |<----RGMII----->| PHY Slave |<------>| PHY Master |
|<--- 125 MHz ---+-<------/ | | \ |
------/ \-----------/ \------------/
^
\-TX_TCLK

-------------------------------------------------------------------------------

Since some clock or link related issues are only reproducible in a
specific MASTER-SLAVE-role, MAC and PHY configuration, it is beneficial
to provide generic (not 100BASE-T1 specific) interface to the user space
for configuration flexibility and trouble shooting.

Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
---
Documentation/networking/ethtool-netlink.rst | 2 +
drivers/net/phy/phy.c | 3 +-
drivers/net/phy/phy_device.c | 88 ++++++++++++++++++++
include/linux/phy.h | 2 +
include/uapi/linux/ethtool.h | 17 +++-
include/uapi/linux/ethtool_netlink.h | 1 +
include/uapi/linux/mii.h | 2 +
net/ethtool/linkmodes.c | 9 +-
8 files changed, 121 insertions(+), 3 deletions(-)

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index f1f868479ceb8..83127a6e42b17 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -368,6 +368,7 @@ Kernel response contents:
``ETHTOOL_A_LINKMODES_PEER`` bitset partner link modes
``ETHTOOL_A_LINKMODES_SPEED`` u32 link speed (Mb/s)
``ETHTOOL_A_LINKMODES_DUPLEX`` u8 duplex mode
+ ``ETHTOOL_A_LINKMODES_MASTER_SLAVE`` u8 Master/slave port mode
==================================== ====== ==========================

For ``ETHTOOL_A_LINKMODES_OURS``, value represents advertised modes and mask
@@ -390,6 +391,7 @@ Request contents:
``ETHTOOL_A_LINKMODES_PEER`` bitset partner link modes
``ETHTOOL_A_LINKMODES_SPEED`` u32 link speed (Mb/s)
``ETHTOOL_A_LINKMODES_DUPLEX`` u8 duplex mode
+ ``ETHTOOL_A_LINKMODES_MASTER_SLAVE`` u8 Master/slave port mode
==================================== ====== ==========================

``ETHTOOL_A_LINKMODES_OURS`` bit set allows setting advertised link modes. If
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index d76e038cf2cb5..02625b0adebaf 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -294,7 +294,7 @@ int phy_ethtool_ksettings_set(struct phy_device *phydev,
phydev->advertising, autoneg == AUTONEG_ENABLE);

phydev->duplex = duplex;
-
+ phydev->master_slave_set = cmd->base.master_slave;
phydev->mdix_ctrl = cmd->base.eth_tp_mdix_ctrl;

/* Restart the PHY */
@@ -313,6 +313,7 @@ void phy_ethtool_ksettings_get(struct phy_device *phydev,

cmd->base.speed = phydev->speed;
cmd->base.duplex = phydev->duplex;
+ cmd->base.master_slave = phydev->master_slave_get;
if (phydev->interface == PHY_INTERFACE_MODE_MOCA)
cmd->base.port = PORT_BNC;
else
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index c8b0c34030d32..da75a91df5d90 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -9,6 +9,7 @@

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

+#include <linux/bitfield.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
@@ -1772,6 +1773,83 @@ int genphy_setup_forced(struct phy_device *phydev)
}
EXPORT_SYMBOL(genphy_setup_forced);

+static int genphy_setup_master_slave(struct phy_device *phydev)
+{
+ u16 ctl = 0;
+
+ if (!phydev->is_gigabit_capable)
+ return 0;
+
+ switch (FIELD_GET(PORT_MODE_CFG_MASK, phydev->master_slave_set)) {
+ case PORT_MODE_CFG_MASTER_PREFERRED:
+ ctl |= CTL1000_PREFER_MASTER;
+ break;
+ case PORT_MODE_CFG_SLAVE_PREFERRED:
+ break;
+ case PORT_MODE_CFG_MASTER_FORCE:
+ ctl |= CTL1000_AS_MASTER;
+ /* fallthrough */
+ case PORT_MODE_CFG_SLAVE_FORCE:
+ ctl |= CTL1000_ENABLE_MASTER;
+ break;
+ case PORT_MODE_CFG_UNKNOWN:
+ return 0;
+ default:
+ phydev_warn(phydev, "Unsupported Master/Slave mode\n");
+ return 0;
+ }
+
+ return phy_modify_changed(phydev, MII_CTRL1000,
+ (CTL1000_ENABLE_MASTER | CTL1000_AS_MASTER |
+ CTL1000_PREFER_MASTER), ctl);
+}
+
+static int genphy_read_master_slave(struct phy_device *phydev)
+{
+ int cfg, state = 0;
+ u16 val;
+
+ phydev->master_slave_get = 0;
+
+ if (!phydev->is_gigabit_capable)
+ return 0;
+
+ val = phy_read(phydev, MII_CTRL1000);
+ if (val < 0)
+ return val;
+
+ if (val & CTL1000_ENABLE_MASTER) {
+ if (val & CTL1000_AS_MASTER)
+ cfg = PORT_MODE_CFG_MASTER_FORCE;
+ else
+ cfg = PORT_MODE_CFG_SLAVE_FORCE;
+ } else {
+ if (val & CTL1000_PREFER_MASTER)
+ cfg = PORT_MODE_CFG_MASTER_PREFERRED;
+ else
+ cfg = PORT_MODE_CFG_SLAVE_PREFERRED;
+ }
+
+ val = phy_read(phydev, MII_STAT1000);
+ if (val < 0)
+ return val;
+
+ if (val & LPA_1000MSFAIL) {
+ state = PORT_MODE_STATE_ERR;
+ } else if (phydev->link) {
+ /* this bits are valid only for active link */
+ if (val & LPA_1000MSRES)
+ state = PORT_MODE_STATE_MASTER;
+ else
+ state = PORT_MODE_STATE_SLAVE;
+ }
+
+ phydev->master_slave_get = FIELD_PREP(PORT_MODE_CFG_MASK, cfg) |
+ FIELD_PREP(PORT_MODE_STATE_MASK, state);
+
+ return 0;
+}
+
/**
* genphy_restart_aneg - Enable and Restart Autonegotiation
* @phydev: target phy_device struct
@@ -1830,6 +1908,12 @@ int __genphy_config_aneg(struct phy_device *phydev, bool changed)
if (genphy_config_eee_advert(phydev))
changed = true;

+ err = genphy_setup_master_slave(phydev);
+ if (err < 0)
+ return err;
+ else if (err)
+ changed = true;
+
if (AUTONEG_ENABLE != phydev->autoneg)
return genphy_setup_forced(phydev);

@@ -2063,6 +2147,10 @@ int genphy_read_status(struct phy_device *phydev)
phydev->pause = 0;
phydev->asym_pause = 0;

+ err = genphy_read_master_slave(phydev);
+ if (err < 0)
+ return err;
+
err = genphy_read_lpa(phydev);
if (err < 0)
return err;
diff --git a/include/linux/phy.h b/include/linux/phy.h
index c570e162e05e5..1e9f49037167f 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -421,6 +421,8 @@ struct phy_device {
int duplex;
int pause;
int asym_pause;
+ u8 master_slave_get;
+ u8 master_slave_set;

/* Union of PHY and Attached devices' supported link modes */
/* See ethtool.h for more info */
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 2405ab2263779..0bbd6c790e2eb 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -1659,6 +1659,19 @@ static inline int ethtool_validate_duplex(__u8 duplex)
return 0;
}

+/* Port mode */
+#define PORT_MODE_CFG_MASK 0x07
+#define PORT_MODE_CFG_UNKNOWN 0
+#define PORT_MODE_CFG_MASTER_PREFERRED 1
+#define PORT_MODE_CFG_SLAVE_PREFERRED 2
+#define PORT_MODE_CFG_MASTER_FORCE 3
+#define PORT_MODE_CFG_SLAVE_FORCE 4
+#define PORT_MODE_STATE_MASK 0x38
+#define PORT_MODE_STATE_UNKNOWN 0
+#define PORT_MODE_STATE_MASTER 1
+#define PORT_MODE_STATE_SLAVE 2
+#define PORT_MODE_STATE_ERR 3
+
/* Which connector port. */
#define PORT_TP 0x00
#define PORT_AUI 0x01
@@ -1850,6 +1863,7 @@ enum ethtool_reset_flags {
* autonegotiation; 0 if unknown or not applicable. Read-only.
* @transceiver: Used to distinguish different possible PHY types,
* reported consistently by PHYLIB. Read-only.
+ * @master_slave: Master or slave port mode.
*
* If autonegotiation is disabled, the speed and @duplex represent the
* fixed link mode and are writable if the driver supports multiple
@@ -1897,7 +1911,8 @@ struct ethtool_link_settings {
__u8 eth_tp_mdix_ctrl;
__s8 link_mode_masks_nwords;
__u8 transceiver;
- __u8 reserved1[3];
+ __u8 master_slave;
+ __u8 reserved1[2];
__u32 reserved[7];
__u32 link_mode_masks[0];
/* layout of link_mode_masks fields:
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 7e0b460f872c0..e04d47cb5f227 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -185,6 +185,7 @@ enum {
ETHTOOL_A_LINKMODES_PEER, /* bitset */
ETHTOOL_A_LINKMODES_SPEED, /* u32 */
ETHTOOL_A_LINKMODES_DUPLEX, /* u8 */
+ ETHTOOL_A_LINKMODES_MASTER_SLAVE, /* u8 */

/* add new constants above here */
__ETHTOOL_A_LINKMODES_CNT,
diff --git a/include/uapi/linux/mii.h b/include/uapi/linux/mii.h
index 0b9c3beda345b..78eac603a84fb 100644
--- a/include/uapi/linux/mii.h
+++ b/include/uapi/linux/mii.h
@@ -146,11 +146,13 @@
/* 1000BASE-T Control register */
#define ADVERTISE_1000FULL 0x0200 /* Advertise 1000BASE-T full duplex */
#define ADVERTISE_1000HALF 0x0100 /* Advertise 1000BASE-T half duplex */
+#define CTL1000_PREFER_MASTER 0x0400 /* prefer to operate as master */
#define CTL1000_AS_MASTER 0x0800
#define CTL1000_ENABLE_MASTER 0x1000

/* 1000BASE-T Status register */
#define LPA_1000MSFAIL 0x8000 /* Master/Slave resolution failure */
+#define LPA_1000MSRES 0x4000 /* Master/Slave resolution status */
#define LPA_1000LOCALRXOK 0x2000 /* Link partner local receiver status */
#define LPA_1000REMRXOK 0x1000 /* Link partner remote receiver status */
#define LPA_1000FULL 0x0800 /* Link partner 1000BASE-T full duplex */
diff --git a/net/ethtool/linkmodes.c b/net/ethtool/linkmodes.c
index 96f20be64553e..dc15b88e64c6a 100644
--- a/net/ethtool/linkmodes.c
+++ b/net/ethtool/linkmodes.c
@@ -27,6 +27,7 @@ linkmodes_get_policy[ETHTOOL_A_LINKMODES_MAX + 1] = {
[ETHTOOL_A_LINKMODES_PEER] = { .type = NLA_REJECT },
[ETHTOOL_A_LINKMODES_SPEED] = { .type = NLA_REJECT },
[ETHTOOL_A_LINKMODES_DUPLEX] = { .type = NLA_REJECT },
+ [ETHTOOL_A_LINKMODES_MASTER_SLAVE] = { .type = NLA_REJECT },
};

static int linkmodes_prepare_data(const struct ethnl_req_info *req_base,
@@ -69,6 +70,7 @@ static int linkmodes_reply_size(const struct ethnl_req_info *req_base,
len = nla_total_size(sizeof(u8)) /* LINKMODES_AUTONEG */
+ nla_total_size(sizeof(u32)) /* LINKMODES_SPEED */
+ nla_total_size(sizeof(u8)) /* LINKMODES_DUPLEX */
+ + nla_total_size(sizeof(u8)) /* LINKMODES_MASTER_SLAVE */
+ 0;
ret = ethnl_bitset_size(ksettings->link_modes.advertising,
ksettings->link_modes.supported,
@@ -119,7 +121,9 @@ static int linkmodes_fill_reply(struct sk_buff *skb,
}

if (nla_put_u32(skb, ETHTOOL_A_LINKMODES_SPEED, lsettings->speed) ||
- nla_put_u8(skb, ETHTOOL_A_LINKMODES_DUPLEX, lsettings->duplex))
+ nla_put_u8(skb, ETHTOOL_A_LINKMODES_DUPLEX, lsettings->duplex) ||
+ nla_put_u8(skb, ETHTOOL_A_LINKMODES_MASTER_SLAVE,
+ lsettings->master_slave))
return -EMSGSIZE;

return 0;
@@ -248,6 +252,7 @@ linkmodes_set_policy[ETHTOOL_A_LINKMODES_MAX + 1] = {
[ETHTOOL_A_LINKMODES_PEER] = { .type = NLA_REJECT },
[ETHTOOL_A_LINKMODES_SPEED] = { .type = NLA_U32 },
[ETHTOOL_A_LINKMODES_DUPLEX] = { .type = NLA_U8 },
+ [ETHTOOL_A_LINKMODES_MASTER_SLAVE] = { .type = NLA_U8 },
};

/* Set advertised link modes to all supported modes matching requested speed
@@ -310,6 +315,8 @@ static int ethnl_update_linkmodes(struct genl_info *info, struct nlattr **tb,
mod);
ethnl_update_u8(&lsettings->duplex, tb[ETHTOOL_A_LINKMODES_DUPLEX],
mod);
+ ethnl_update_u8(&lsettings->master_slave,
+ tb[ETHTOOL_A_LINKMODES_MASTER_SLAVE], mod);

if (!tb[ETHTOOL_A_LINKMODES_OURS] && lsettings->autoneg &&
(req_speed || req_duplex) &&
--
2.26.1