[PATCH net-next v10 1/5] net: phy: Allow loopback speed selection for PHY drivers

Gerhard Engleder
2025-03-12T20:30:23Z

PHY drivers support loopback mode, but it is not possible to select the
speed of the loopback mode. The speed is chosen by the set_loopback()
operation of the PHY driver. Same is valid for genphy_loopback().

There are PHYs that support loopback with different speeds. Extend
set_loopback() to make loopback speed selection possible.

Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
drivers/net/phy/adin1100.c | 5 ++++-
drivers/net/phy/dp83867.c | 5 ++++-
drivers/net/phy/marvell.c | 8 +++++++-
drivers/net/phy/mxl-gpy.c | 11 +++++++----
drivers/net/phy/phy-c45.c | 5 ++++-
drivers/net/phy/phy_device.c | 12 +++++++++---
drivers/net/phy/xilinx_gmii2rgmii.c | 7 ++++---
include/linux/phy.h | 16 ++++++++++++----
8 files changed, 51 insertions(+), 18 deletions(-)

diff --git a/drivers/net/phy/adin1100.c b/drivers/net/phy/adin1100.c
index 6bb469429b9d..bd7a47a903ac 100644
--- a/drivers/net/phy/adin1100.c
+++ b/drivers/net/phy/adin1100.c
@@ -215,8 +215,11 @@ static int adin_resume(struct phy_device *phydev)
return adin_set_powerdown_mode(phydev, false);
}

-static int adin_set_loopback(struct phy_device *phydev, bool enable)
+static int adin_set_loopback(struct phy_device *phydev, bool enable, int speed)
{
+ if (enable && speed)
+ return -EOPNOTSUPP;
+
if (enable)
return phy_set_bits_mmd(phydev, MDIO_MMD_PCS, MDIO_PCS_10T1L_CTRL,
BMCR_LOOPBACK);
diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c
index c1451df430ac..063266cafe9c 100644
--- a/drivers/net/phy/dp83867.c
+++ b/drivers/net/phy/dp83867.c
@@ -1009,8 +1009,11 @@ static void dp83867_link_change_notify(struct phy_device *phydev)
}
}

-static int dp83867_loopback(struct phy_device *phydev, bool enable)
+static int dp83867_loopback(struct phy_device *phydev, bool enable, int speed)
{
+ if (enable && speed)
+ return -EOPNOTSUPP;
+
return phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK,
enable ? BMCR_LOOPBACK : 0);
}
diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c
index dd254e36ca8a..f2ad675537d1 100644
--- a/drivers/net/phy/marvell.c
+++ b/drivers/net/phy/marvell.c
@@ -2131,13 +2131,19 @@ static void marvell_get_stats_simple(struct phy_device *phydev,
data[i] = marvell_get_stat_simple(phydev, i);
}

-static int m88e1510_loopback(struct phy_device *phydev, bool enable)
+static int m88e1510_loopback(struct phy_device *phydev, bool enable, int speed)
{
int err;

if (enable) {
u16 bmcr_ctl, mscr2_ctl = 0;

+ if (speed == SPEED_10 || speed == SPEED_100 ||
+ speed == SPEED_1000)
+ phydev->speed = speed;
+ else if (speed)
+ return -EINVAL;
+
bmcr_ctl = mii_bmcr_encode_fixed(phydev->speed, phydev->duplex);

err = phy_write(phydev, MII_BMCR, bmcr_ctl);
diff --git a/drivers/net/phy/mxl-gpy.c b/drivers/net/phy/mxl-gpy.c
index 94d9cb727121..a6cca8d43253 100644
--- a/drivers/net/phy/mxl-gpy.c
+++ b/drivers/net/phy/mxl-gpy.c
@@ -813,7 +813,7 @@ static void gpy_get_wol(struct phy_device *phydev,
wol->wolopts = priv->wolopts;
}

-static int gpy_loopback(struct phy_device *phydev, bool enable)
+static int gpy_loopback(struct phy_device *phydev, bool enable, int speed)
{
struct gpy_priv *priv = phydev->priv;
u16 set = 0;
@@ -822,6 +822,9 @@ static int gpy_loopback(struct phy_device *phydev, bool enable)
if (enable) {
u64 now = get_jiffies_64();

+ if (speed)
+ return -EOPNOTSUPP;
+
/* wait until 3 seconds from last disable */
if (time_before64(now, priv->lb_dis_to))
msleep(jiffies64_to_msecs(priv->lb_dis_to - now));
@@ -845,15 +848,15 @@ static int gpy_loopback(struct phy_device *phydev, bool enable)
return 0;
}

-static int gpy115_loopback(struct phy_device *phydev, bool enable)
+static int gpy115_loopback(struct phy_device *phydev, bool enable, int speed)
{
struct gpy_priv *priv = phydev->priv;

if (enable)
- return gpy_loopback(phydev, enable);
+ return gpy_loopback(phydev, enable, speed);

if (priv->fw_minor > 0x76)
- return gpy_loopback(phydev, 0);
+ return gpy_loopback(phydev, 0, 0);

return genphy_soft_reset(phydev);
}
diff --git a/drivers/net/phy/phy-c45.c b/drivers/net/phy/phy-c45.c
index 0bcbdce38107..8a0ffc3174ec 100644
--- a/drivers/net/phy/phy-c45.c
+++ b/drivers/net/phy/phy-c45.c
@@ -1228,8 +1228,11 @@ int gen10g_config_aneg(struct phy_device *phydev)
}
EXPORT_SYMBOL_GPL(gen10g_config_aneg);

-int genphy_c45_loopback(struct phy_device *phydev, bool enable)
+int genphy_c45_loopback(struct phy_device *phydev, bool enable, int speed)
{
+ if (enable && speed)
+ return -EOPNOTSUPP;
+
return phy_modify_mmd(phydev, MDIO_MMD_PCS, MDIO_CTRL1,
MDIO_PCS_CTRL1_LOOPBACK,
enable ? MDIO_PCS_CTRL1_LOOPBACK : 0);
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index b2d32fbc8c85..b6828019c34c 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1837,9 +1837,9 @@ int phy_loopback(struct phy_device *phydev, bool enable)
}

if (phydev->drv->set_loopback)
- ret = phydev->drv->set_loopback(phydev, enable);
+ ret = phydev->drv->set_loopback(phydev, enable, 0);
else
- ret = genphy_loopback(phydev, enable);
+ ret = genphy_loopback(phydev, enable, 0);

if (ret)
goto out;
@@ -2608,12 +2608,18 @@ int genphy_resume(struct phy_device *phydev)
}
EXPORT_SYMBOL(genphy_resume);

-int genphy_loopback(struct phy_device *phydev, bool enable)
+int genphy_loopback(struct phy_device *phydev, bool enable, int speed)
{
if (enable) {
u16 ctl = BMCR_LOOPBACK;
int ret, val;

+ if (speed == SPEED_10 || speed == SPEED_100 ||
+ speed == SPEED_1000)
+ phydev->speed = speed;
+ else if (speed)
+ return -EINVAL;
+
ctl |= mii_bmcr_encode_fixed(phydev->speed, phydev->duplex);

phy_modify(phydev, MII_BMCR, ~0, ctl);
diff --git a/drivers/net/phy/xilinx_gmii2rgmii.c b/drivers/net/phy/xilinx_gmii2rgmii.c
index 7c51daecf18e..2024d8ef36d9 100644
--- a/drivers/net/phy/xilinx_gmii2rgmii.c
+++ b/drivers/net/phy/xilinx_gmii2rgmii.c
@@ -64,15 +64,16 @@ static int xgmiitorgmii_read_status(struct phy_device *phydev)
return 0;
}

-static int xgmiitorgmii_set_loopback(struct phy_device *phydev, bool enable)
+static int xgmiitorgmii_set_loopback(struct phy_device *phydev, bool enable,
+ int speed)
{
struct gmii2rgmii *priv = mdiodev_get_drvdata(&phydev->mdio);
int err;

if (priv->phy_drv->set_loopback)
- err = priv->phy_drv->set_loopback(phydev, enable);
+ err = priv->phy_drv->set_loopback(phydev, enable, speed);
else
- err = genphy_loopback(phydev, enable);
+ err = genphy_loopback(phydev, enable, speed);
if (err < 0)
return err;

diff --git a/include/linux/phy.h b/include/linux/phy.h
index c4a6385faf41..e8e42888f3e1 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -1136,8 +1136,16 @@ struct phy_driver {
int (*set_tunable)(struct phy_device *dev,
struct ethtool_tunable *tuna,
const void *data);
- /** @set_loopback: Set the loopback mood of the PHY */
- int (*set_loopback)(struct phy_device *dev, bool enable);
+ /**
+ * @set_loopback: Set the loopback mode of the PHY
+ * enable selects if the loopback mode is enabled or disabled. If the
+ * loopback mode is enabled, then the speed of the loopback mode can be
+ * requested with the speed argument. If the speed argument is zero,
+ * then any speed can be selected. If the speed argument is > 0, then
+ * this speed shall be selected for the loopback mode or EOPNOTSUPP
+ * shall be returned if speed selection is not supported.
+ */
+ int (*set_loopback)(struct phy_device *dev, bool enable, int speed);
/** @get_sqi: Get the signal quality indication */
int (*get_sqi)(struct phy_device *dev);
/** @get_sqi_max: Get the maximum signal quality indication */
@@ -1930,7 +1938,7 @@ int genphy_read_status(struct phy_device *phydev);
int genphy_read_master_slave(struct phy_device *phydev);
int genphy_suspend(struct phy_device *phydev);
int genphy_resume(struct phy_device *phydev);
-int genphy_loopback(struct phy_device *phydev, bool enable);
+int genphy_loopback(struct phy_device *phydev, bool enable, int speed);
int genphy_soft_reset(struct phy_device *phydev);
irqreturn_t genphy_handle_interrupt_no_ack(struct phy_device *phydev);

@@ -1972,7 +1980,7 @@ int genphy_c45_pma_baset1_read_master_slave(struct phy_device *phydev);
int genphy_c45_read_status(struct phy_device *phydev);
int genphy_c45_baset1_read_status(struct phy_device *phydev);
int genphy_c45_config_aneg(struct phy_device *phydev);
-int genphy_c45_loopback(struct phy_device *phydev, bool enable);
+int genphy_c45_loopback(struct phy_device *phydev, bool enable, int speed);
int genphy_c45_pma_resume(struct phy_device *phydev);
int genphy_c45_pma_suspend(struct phy_device *phydev);
int genphy_c45_fast_retrain(struct phy_device *phydev, bool enable);
--
2.39.5