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 <[email protected]>
---
Documentation/networking/ethtool-netlink.rst | 35 ++++----
drivers/net/phy/phy.c | 4 +-
drivers/net/phy/phy_device.c | 94 ++++++++++++++++++++
include/linux/phy.h | 3 +
include/uapi/linux/ethtool.h | 16 +++-
include/uapi/linux/ethtool_netlink.h | 2 +
include/uapi/linux/mii.h | 2 +
net/ethtool/ioctl.c | 6 ++
net/ethtool/linkmodes.c | 53 +++++++++++
9 files changed, 197 insertions(+), 18 deletions(-)
diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 567326491f80b..8f5cefc539cf1 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -392,14 +392,16 @@ Request contents:
Kernel response contents:
- ==================================== ====== ==========================
- ``ETHTOOL_A_LINKMODES_HEADER`` nested reply header
- ``ETHTOOL_A_LINKMODES_AUTONEG`` u8 autonegotiation status
- ``ETHTOOL_A_LINKMODES_OURS`` bitset advertised link modes
- ``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_HEADER`` nested reply header
+ ``ETHTOOL_A_LINKMODES_AUTONEG`` u8 autonegotiation status
+ ``ETHTOOL_A_LINKMODES_OURS`` bitset advertised link modes
+ ``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_CFG`` u8 Master/slave port mode
+ ``ETHTOOL_A_LINKMODES_MASTER_SLAVE_STATE`` u8 Master/slave port state
+ ========================================== ====== ==========================
For ``ETHTOOL_A_LINKMODES_OURS``, value represents advertised modes and mask
represents supported modes. ``ETHTOOL_A_LINKMODES_PEER`` in the reply is a bit
@@ -414,14 +416,15 @@ LINKMODES_SET
Request contents:
- ==================================== ====== ==========================
- ``ETHTOOL_A_LINKMODES_HEADER`` nested request header
- ``ETHTOOL_A_LINKMODES_AUTONEG`` u8 autonegotiation status
- ``ETHTOOL_A_LINKMODES_OURS`` bitset advertised link modes
- ``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_HEADER`` nested request header
+ ``ETHTOOL_A_LINKMODES_AUTONEG`` u8 autonegotiation status
+ ``ETHTOOL_A_LINKMODES_OURS`` bitset advertised link modes
+ ``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_CFG`` u8 Master/slave port mode
+ ========================================== ====== ==========================
``ETHTOOL_A_LINKMODES_OURS`` bit set allows setting advertised link modes. If
autonegotiation is on (either set now or kept from before), advertised modes
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 72c69a9c8a98a..8c22d02b4218e 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -295,7 +295,7 @@ 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_cfg;
phydev->mdix_ctrl = cmd->base.eth_tp_mdix_ctrl;
/* Restart the PHY */
@@ -314,6 +314,8 @@ void phy_ethtool_ksettings_get(struct phy_device *phydev,
cmd->base.speed = phydev->speed;
cmd->base.duplex = phydev->duplex;
+ cmd->base.master_slave_cfg = phydev->master_slave_get;
+ cmd->base.master_slave_state = phydev->master_slave_state;
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 ac2784192472f..42dda9d2082ee 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1768,6 +1768,90 @@ 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 (phydev->master_slave_set) {
+ case MASTER_SLAVE_CFG_MASTER_PREFERRED:
+ ctl |= CTL1000_PREFER_MASTER;
+ break;
+ case MASTER_SLAVE_CFG_SLAVE_PREFERRED:
+ break;
+ case MASTER_SLAVE_CFG_MASTER_FORCE:
+ ctl |= CTL1000_AS_MASTER;
+ /* fallthrough */
+ case MASTER_SLAVE_CFG_SLAVE_FORCE:
+ ctl |= CTL1000_ENABLE_MASTER;
+ break;
+ case MASTER_SLAVE_CFG_UNKNOWN:
+ case MASTER_SLAVE_CFG_UNSUPPORTED:
+ return 0;
+ default:
+ phydev_warn(phydev, "Unsupported Master/Slave mode\n");
+ return -EOPNOTSUPP;
+ }
+
+ 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;
+ u16 val;
+
+ if (!phydev->is_gigabit_capable) {
+ phydev->master_slave_get = MASTER_SLAVE_CFG_UNSUPPORTED;
+ phydev->master_slave_state = MASTER_SLAVE_STATE_UNSUPPORTED;
+ return 0;
+ }
+
+ phydev->master_slave_get = MASTER_SLAVE_CFG_UNKNOWN;
+ phydev->master_slave_state = MASTER_SLAVE_STATE_UNKNOWN;
+
+ val = phy_read(phydev, MII_CTRL1000);
+ if (val < 0)
+ return val;
+
+ if (val & CTL1000_ENABLE_MASTER) {
+ if (val & CTL1000_AS_MASTER)
+ cfg = MASTER_SLAVE_CFG_MASTER_FORCE;
+ else
+ cfg = MASTER_SLAVE_CFG_SLAVE_FORCE;
+ } else {
+ if (val & CTL1000_PREFER_MASTER)
+ cfg = MASTER_SLAVE_CFG_MASTER_PREFERRED;
+ else
+ cfg = MASTER_SLAVE_CFG_SLAVE_PREFERRED;
+ }
+
+ val = phy_read(phydev, MII_STAT1000);
+ if (val < 0)
+ return val;
+
+ if (val & LPA_1000MSFAIL) {
+ state = MASTER_SLAVE_STATE_ERR;
+ } else if (phydev->link) {
+ /* this bits are valid only for active link */
+ if (val & LPA_1000MSRES)
+ state = MASTER_SLAVE_STATE_MASTER;
+ else
+ state = MASTER_SLAVE_STATE_SLAVE;
+ } else {
+ state = MASTER_SLAVE_STATE_UNKNOWN;
+ }
+
+ phydev->master_slave_get = cfg;
+ phydev->master_slave_state = state;
+
+ return 0;
+}
+
/**
* genphy_restart_aneg - Enable and Restart Autonegotiation
* @phydev: target phy_device struct
@@ -1826,6 +1910,12 @@ 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);
@@ -2060,6 +2150,10 @@ 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 2432ca463ddc0..19cd4fe6efbf1 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -431,6 +431,9 @@ struct phy_device {
int duplex;
int pause;
int asym_pause;
+ u8 master_slave_get;
+ u8 master_slave_set;
+ u8 master_slave_state;
/* 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 92f737f101178..f4662b3a9e1ef 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -1666,6 +1666,18 @@ static inline int ethtool_validate_duplex(__u8 duplex)
return 0;
}
+#define MASTER_SLAVE_CFG_UNSUPPORTED 0
+#define MASTER_SLAVE_CFG_UNKNOWN 1
+#define MASTER_SLAVE_CFG_MASTER_PREFERRED 2
+#define MASTER_SLAVE_CFG_SLAVE_PREFERRED 3
+#define MASTER_SLAVE_CFG_MASTER_FORCE 4
+#define MASTER_SLAVE_CFG_SLAVE_FORCE 5
+#define MASTER_SLAVE_STATE_UNSUPPORTED 0
+#define MASTER_SLAVE_STATE_UNKNOWN 1
+#define MASTER_SLAVE_STATE_MASTER 2
+#define MASTER_SLAVE_STATE_SLAVE 3
+#define MASTER_SLAVE_STATE_ERR 4
+
/* Which connector port. */
#define PORT_TP 0x00
#define PORT_AUI 0x01
@@ -1904,7 +1916,9 @@ struct ethtool_link_settings {
__u8 eth_tp_mdix_ctrl;
__s8 link_mode_masks_nwords;
__u8 transceiver;
- __u8 reserved1[3];
+ __u8 master_slave_cfg;
+ __u8 master_slave_state;
+ __u8 reserved1[1];
__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 7fde76366ba46..bf1d310e20bc6 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -216,6 +216,8 @@ enum {
ETHTOOL_A_LINKMODES_PEER, /* bitset */
ETHTOOL_A_LINKMODES_SPEED, /* u32 */
ETHTOOL_A_LINKMODES_DUPLEX, /* u8 */
+ ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG, /* u8 */
+ ETHTOOL_A_LINKMODES_MASTER_SLAVE_STATE, /* 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 90f9b4e1ba277..39f7c44baf535 100644
--- a/include/uapi/linux/mii.h
+++ b/include/uapi/linux/mii.h
@@ -151,11 +151,13 @@
/* 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/ioctl.c b/net/ethtool/ioctl.c
index 89d0b1827aaff..525e8865f511f 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -553,6 +553,8 @@ static int ethtool_get_link_ksettings(struct net_device *dev,
link_ksettings.base.cmd = ETHTOOL_GLINKSETTINGS;
link_ksettings.base.link_mode_masks_nwords
= __ETHTOOL_LINK_MODE_MASK_NU32;
+ link_ksettings.base.master_slave_cfg = MASTER_SLAVE_CFG_UNSUPPORTED;
+ link_ksettings.base.master_slave_state = MASTER_SLAVE_STATE_UNSUPPORTED;
return store_link_ksettings_for_user(useraddr, &link_ksettings);
}
@@ -590,6 +592,10 @@ static int ethtool_set_link_ksettings(struct net_device *dev,
!= link_ksettings.base.link_mode_masks_nwords)
return -EINVAL;
+ if (link_ksettings.base.master_slave_cfg ||
+ link_ksettings.base.master_slave_state)
+ return -EINVAL;
+
err = dev->ethtool_ops->set_link_ksettings(dev, &link_ksettings);
if (err >= 0) {
ethtool_notify(dev, ETHTOOL_MSG_LINKINFO_NTF, NULL);
diff --git a/net/ethtool/linkmodes.c b/net/ethtool/linkmodes.c
index 452608c6d8562..fd4f3e58c6f62 100644
--- a/net/ethtool/linkmodes.c
+++ b/net/ethtool/linkmodes.c
@@ -27,6 +27,8 @@ 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_CFG] = { .type = NLA_REJECT },
+ [ETHTOOL_A_LINKMODES_MASTER_SLAVE_STATE] = { .type = NLA_REJECT },
};
static int linkmodes_prepare_data(const struct ethnl_req_info *req_base,
@@ -63,6 +65,7 @@ static int linkmodes_reply_size(const struct ethnl_req_info *req_base,
{
const struct linkmodes_reply_data *data = LINKMODES_REPDATA(reply_base);
const struct ethtool_link_ksettings *ksettings = &data->ksettings;
+ const struct ethtool_link_settings *lsettings = &ksettings->base;
bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
int len, ret;
@@ -86,6 +89,12 @@ static int linkmodes_reply_size(const struct ethnl_req_info *req_base,
len += ret;
}
+ if (lsettings->master_slave_cfg != MASTER_SLAVE_CFG_UNSUPPORTED)
+ len += nla_total_size(sizeof(u8));
+
+ if (lsettings->master_slave_state != MASTER_SLAVE_STATE_UNSUPPORTED)
+ len += nla_total_size(sizeof(u8));
+
return len;
}
@@ -122,6 +131,16 @@ static int linkmodes_fill_reply(struct sk_buff *skb,
nla_put_u8(skb, ETHTOOL_A_LINKMODES_DUPLEX, lsettings->duplex))
return -EMSGSIZE;
+ if (lsettings->master_slave_cfg != MASTER_SLAVE_CFG_UNSUPPORTED &&
+ nla_put_u8(skb, ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG,
+ lsettings->master_slave_cfg))
+ return -EMSGSIZE;
+
+ if (lsettings->master_slave_state != MASTER_SLAVE_STATE_UNSUPPORTED &&
+ nla_put_u8(skb, ETHTOOL_A_LINKMODES_MASTER_SLAVE_STATE,
+ lsettings->master_slave_state))
+ return -EMSGSIZE;
+
return 0;
}
@@ -249,6 +268,8 @@ 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_CFG] = { .type = NLA_U8 },
+ [ETHTOOL_A_LINKMODES_MASTER_SLAVE_STATE] = { .type = NLA_REJECT },
};
/* Set advertised link modes to all supported modes matching requested speed
@@ -287,14 +308,45 @@ static bool ethnl_auto_linkmodes(struct ethtool_link_ksettings *ksettings,
__ETHTOOL_LINK_MODE_MASK_NBITS);
}
+static bool ethnl_validate_master_slave_cfg(u8 cfg)
+{
+ switch (cfg) {
+ case MASTER_SLAVE_CFG_MASTER_PREFERRED:
+ case MASTER_SLAVE_CFG_SLAVE_PREFERRED:
+ case MASTER_SLAVE_CFG_MASTER_FORCE:
+ case MASTER_SLAVE_CFG_SLAVE_FORCE:
+ return true;
+ }
+
+ return false;
+}
+
static int ethnl_update_linkmodes(struct genl_info *info, struct nlattr **tb,
struct ethtool_link_ksettings *ksettings,
bool *mod)
{
struct ethtool_link_settings *lsettings = &ksettings->base;
bool req_speed, req_duplex;
+ const struct nlattr *master_slave_cfg;
int ret;
+ master_slave_cfg = tb[ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG];
+ if (master_slave_cfg) {
+ u8 cfg = nla_get_u8(master_slave_cfg);
+
+ if (lsettings->master_slave_cfg == MASTER_SLAVE_CFG_UNSUPPORTED) {
+ NL_SET_ERR_MSG_ATTR(info->extack, master_slave_cfg,
+ "master/slave configuration not supported by device");
+ return -EOPNOTSUPP;
+ }
+
+ if (!ethnl_validate_master_slave_cfg(cfg)) {
+ NL_SET_ERR_MSG_ATTR(info->extack, master_slave_cfg,
+ "master/slave value is invalid");
+ return -EOPNOTSUPP;
+ }
+ }
+
*mod = false;
req_speed = tb[ETHTOOL_A_LINKMODES_SPEED];
req_duplex = tb[ETHTOOL_A_LINKMODES_DUPLEX];
@@ -311,6 +363,7 @@ 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_cfg, master_slave_cfg, mod);
if (!tb[ETHTOOL_A_LINKMODES_OURS] && lsettings->autoneg &&
(req_speed || req_duplex) &&
--
2.26.2
On Tue, May 05, 2020 at 08:35:05AM +0200, Oleksij Rempel wrote:
> 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 <[email protected]>
> ---
I'm OK with the ethtool part and interface between ethtool and phy code
but I'm not confident to review the low level genphy stuff so it would
be nice if someone could check that.
Michal
On Tue, May 05, 2020 at 08:35:05AM +0200, Oleksij Rempel wrote:
> 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 <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
One issue we might run into in the future is that there is a PHY which
has standardized auto-neg, but not master/slave support. The PHY
driver cannot override genphy_read_master_slave(phydev) and
genphy_setup_master_slave(phydev). So we might need to provide ops for
these in the driver structure. But we can delay this until we have
such a device.
Andrew