Merge branch 'net-ptp-driver-opt-in-for-supported-ptp-ioctl-flags'

Jacob Keller says:

====================
net: ptp: driver opt-in for supported PTP ioctl flags

Both the PTP_EXTTS_REQUEST(2) and PTP_PEROUT_REQUEST(2) ioctls take flags
from userspace to modify their behavior. Drivers are supposed to check
these flags, rejecting requests for flags they do not support.

Many drivers today do not check these flags, despite many attempts to
squash individual drivers as these mistakes are discovered. Additionally,
any new flags added can require updating every driver if their validation
checks are poorly implemented.

It is clear that driver authors will not reliably check for unsupported
flags. The root of the issue is that drivers must essentially opt out of
every flag, rather than opt in to the ones they support.

Instead, lets introduce .supported_perout_flags and .supported_extts_flags
to the ptp_clock_info structure. This is a pattern taken from several
ethtool ioctls which enabled validation to move out of the drivers and into
the shared ioctl handlers. This pattern has worked quite well and makes it
much more difficult for drivers to accidentally accept flags they do not
support.

With this approach, drivers which do not set the supported fields will have
the core automatically reject any request which has flags. Drivers must opt
in to each flag they support by adding it to the list, with the sole
exception being the PTP_ENABLE_FEATURE flag of the PTP_EXTTS_REQUEST ioctl
since it is entirely handled by the ptp_chardev.c file.

This change will ensure that all current and future drivers are safe for
extension when we need to extend these ioctls.

I opted to keep all the driver changes into one patch per ioctl type. The
changes are relatively small and straight forward. Splitting it per-driver
would make the series large, and also break flags between the introduction
of the supported field and setting it in each driver.

The non-Intel drivers are compile-tested only, and I would appreciate
confirmation and testing from their respective maintainers. (It is also
likely that I missed some of the driver authors especially for drivers
which didn't make any checks at all and do not set either of the supported
flags yet)

v1: https://lore.kernel.org/20250408-jk-supported-perout-flags-v1-0-d2f8e3df64f3@intel.com
====================

Link: https://patch.msgid.link/20250414-jk-supported-perout-flags-v2-0-f6b17d15475c@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

20 files changed, 91 insertions, 168 deletions

diff --git a/drivers/net/dsa/mv88e6xxx/ptp.c b/drivers/net/dsa/mv88e6xxx/ptp.c
index aed4a4b07f34..1d3b2c94c53e 100644
--- a/drivers/net/dsa/mv88e6xxx/ptp.c
+++ b/drivers/net/dsa/mv88e6xxx/ptp.c
@@ -332,13 +332,6 @@ static int mv88e6352_ptp_enable_extts(struct mv88e6xxx_chip *chip,
 	int pin;
 	int err;
 
-	/* Reject requests with unsupported flags */
-	if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
-				PTP_RISING_EDGE |
-				PTP_FALLING_EDGE |
-				PTP_STRICT_FLAGS))
-		return -EOPNOTSUPP;
-
 	/* Reject requests to enable time stamping on both edges. */
 	if ((rq->extts.flags & PTP_STRICT_FLAGS) &&
 	    (rq->extts.flags & PTP_ENABLE_FEATURE) &&
@@ -566,6 +559,10 @@ int mv88e6xxx_ptp_setup(struct mv88e6xxx_chip *chip)
 	chip->ptp_clock_info.verify	= ptp_ops->ptp_verify;
 	chip->ptp_clock_info.do_aux_work = mv88e6xxx_hwtstamp_work;
 
+	chip->ptp_clock_info.supported_extts_flags = PTP_RISING_EDGE |
+						     PTP_FALLING_EDGE |
+						     PTP_STRICT_FLAGS;
+
 	if (ptp_ops->set_ptp_cpu_port) {
 		struct dsa_port *dp;
 		int upstream = 0;
diff --git a/drivers/net/dsa/sja1105/sja1105_ptp.c b/drivers/net/dsa/sja1105/sja1105_ptp.c
index 198e787e8560..3abc64aec411 100644
--- a/drivers/net/dsa/sja1105/sja1105_ptp.c
+++ b/drivers/net/dsa/sja1105/sja1105_ptp.c
@@ -737,10 +737,6 @@ static int sja1105_per_out_enable(struct sja1105_private *priv,
 	if (perout->index != 0)
 		return -EOPNOTSUPP;
 
-	/* Reject requests with unsupported flags */
-	if (perout->flags)
-		return -EOPNOTSUPP;
-
 	mutex_lock(&ptp_data->lock);
 
 	rc = sja1105_change_ptp_clk_pin_func(priv, PTP_PF_PEROUT);
@@ -820,13 +816,6 @@ static int sja1105_extts_enable(struct sja1105_private *priv,
 	if (extts->index != 0)
 		return -EOPNOTSUPP;
 
-	/* Reject requests with unsupported flags */
-	if (extts->flags & ~(PTP_ENABLE_FEATURE |
-			     PTP_RISING_EDGE |
-			     PTP_FALLING_EDGE |
-			     PTP_STRICT_FLAGS))
-		return -EOPNOTSUPP;
-
 	/* We can only enable time stamping on both edges, sadly. */
 	if ((extts->flags & PTP_STRICT_FLAGS) &&
 	    (extts->flags & PTP_ENABLE_FEATURE) &&
@@ -912,6 +901,9 @@ int sja1105_ptp_clock_register(struct dsa_switch *ds)
 		.n_pins		= 1,
 		.n_ext_ts	= 1,
 		.n_per_out	= 1,
+		.supported_extts_flags = PTP_RISING_EDGE |
+					 PTP_FALLING_EDGE |
+					 PTP_STRICT_FLAGS,
 	};
 
 	/* Only used on SJA1105 */
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 0ea5e52303f2..b79a148ed0f2 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -1627,14 +1627,6 @@ static int ice_ptp_cfg_extts(struct ice_pf *pf, struct ptp_extts_request *rq,
 	int pin_desc_idx;
 	u8 tmr_idx;
 
-	/* Reject requests with unsupported flags */
-
-	if (rq->flags & ~(PTP_ENABLE_FEATURE |
-			  PTP_RISING_EDGE |
-			  PTP_FALLING_EDGE |
-			  PTP_STRICT_FLAGS))
-		return -EOPNOTSUPP;
-
 	tmr_idx = hw->func_caps.ts_func_info.tmr_index_owned;
 	chan = rq->index;
 
@@ -1805,9 +1797,6 @@ static int ice_ptp_cfg_perout(struct ice_pf *pf, struct ptp_perout_request *rq,
 	struct ice_hw *hw = &pf->hw;
 	int pin_desc_idx;
 
-	if (rq->flags & ~PTP_PEROUT_PHASE)
-		return -EOPNOTSUPP;
-
 	pin_desc_idx = ice_ptp_find_pin_idx(pf, PTP_PF_PEROUT, rq->index);
 	if (pin_desc_idx < 0)
 		return -EIO;
@@ -2740,6 +2729,11 @@ static void ice_ptp_set_caps(struct ice_pf *pf)
 	info->enable = ice_ptp_gpio_enable;
 	info->verify = ice_verify_pin;
 
+	info->supported_extts_flags = PTP_RISING_EDGE |
+				      PTP_FALLING_EDGE |
+				      PTP_STRICT_FLAGS;
+	info->supported_perout_flags = PTP_PEROUT_PHASE;
+
 	switch (pf->hw.mac_type) {
 	case ICE_MAC_E810:
 		ice_ptp_set_funcs_e810(pf);
diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c
index f323e1c1989f..793c96016288 100644
--- a/drivers/net/ethernet/intel/igb/igb_ptp.c
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
@@ -502,13 +502,6 @@ static int igb_ptp_feature_enable_82580(struct ptp_clock_info *ptp,
 
 	switch (rq->type) {
 	case PTP_CLK_REQ_EXTTS:
-		/* Reject requests with unsupported flags */
-		if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
-					PTP_RISING_EDGE |
-					PTP_FALLING_EDGE |
-					PTP_STRICT_FLAGS))
-			return -EOPNOTSUPP;
-
 		/* Both the rising and falling edge are timestamped */
 		if (rq->extts.flags & PTP_STRICT_FLAGS &&
 		    (rq->extts.flags & PTP_ENABLE_FEATURE) &&
@@ -658,13 +651,6 @@ static int igb_ptp_feature_enable_i210(struct ptp_clock_info *ptp,
 
 	switch (rq->type) {
 	case PTP_CLK_REQ_EXTTS:
-		/* Reject requests with unsupported flags */
-		if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
-					PTP_RISING_EDGE |
-					PTP_FALLING_EDGE |
-					PTP_STRICT_FLAGS))
-			return -EOPNOTSUPP;
-
 		/* Reject requests failing to enable both edges. */
 		if ((rq->extts.flags & PTP_STRICT_FLAGS) &&
 		    (rq->extts.flags & PTP_ENABLE_FEATURE) &&
@@ -1356,6 +1342,9 @@ void igb_ptp_init(struct igb_adapter *adapter)
 		adapter->ptp_caps.n_per_out = IGB_N_PEROUT;
 		adapter->ptp_caps.n_pins = IGB_N_SDP;
 		adapter->ptp_caps.pps = 0;
+		adapter->ptp_caps.supported_extts_flags = PTP_RISING_EDGE |
+							  PTP_FALLING_EDGE |
+							  PTP_STRICT_FLAGS;
 		adapter->ptp_caps.pin_config = adapter->sdp_config;
 		adapter->ptp_caps.adjfine = igb_ptp_adjfine_82580;
 		adapter->ptp_caps.adjtime = igb_ptp_adjtime_82576;
@@ -1378,6 +1367,9 @@ void igb_ptp_init(struct igb_adapter *adapter)
 		adapter->ptp_caps.n_ext_ts = IGB_N_EXTTS;
 		adapter->ptp_caps.n_per_out = IGB_N_PEROUT;
 		adapter->ptp_caps.n_pins = IGB_N_SDP;
+		adapter->ptp_caps.supported_extts_flags = PTP_RISING_EDGE |
+							  PTP_FALLING_EDGE |
+							  PTP_STRICT_FLAGS;
 		adapter->ptp_caps.pps = 1;
 		adapter->ptp_caps.pin_config = adapter->sdp_config;
 		adapter->ptp_caps.adjfine = igb_ptp_adjfine_82580;
diff --git a/drivers/net/ethernet/intel/igc/igc_ptp.c b/drivers/net/ethernet/intel/igc/igc_ptp.c
index 946edbad4302..b6c60b3d0e3a 100644
--- a/drivers/net/ethernet/intel/igc/igc_ptp.c
+++ b/drivers/net/ethernet/intel/igc/igc_ptp.c
@@ -257,13 +257,6 @@ static int igc_ptp_feature_enable_i225(struct ptp_clock_info *ptp,
 
 	switch (rq->type) {
 	case PTP_CLK_REQ_EXTTS:
-		/* Reject requests with unsupported flags */
-		if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
-					PTP_RISING_EDGE |
-					PTP_FALLING_EDGE |
-					PTP_STRICT_FLAGS))
-			return -EOPNOTSUPP;
-
 		/* Reject requests failing to enable both edges. */
 		if ((rq->extts.flags & PTP_STRICT_FLAGS) &&
 		    (rq->extts.flags & PTP_ENABLE_FEATURE) &&
@@ -300,10 +293,6 @@ static int igc_ptp_feature_enable_i225(struct ptp_clock_info *ptp,
 		return 0;
 
 	case PTP_CLK_REQ_PEROUT:
-		/* Reject requests with unsupported flags */
-		if (rq->perout.flags)
-			return -EOPNOTSUPP;
-
 		if (on) {
 			pin = ptp_find_pin(igc->ptp_clock, PTP_PF_PEROUT,
 					   rq->perout.index);
@@ -1146,6 +1135,9 @@ void igc_ptp_init(struct igc_adapter *adapter)
 		adapter->ptp_caps.pin_config = adapter->sdp_config;
 		adapter->ptp_caps.n_ext_ts = IGC_N_EXTTS;
 		adapter->ptp_caps.n_per_out = IGC_N_PEROUT;
+		adapter->ptp_caps.supported_extts_flags = PTP_RISING_EDGE |
+							  PTP_FALLING_EDGE |
+							  PTP_STRICT_FLAGS;
 		adapter->ptp_caps.n_pins = IGC_N_SDP;
 		adapter->ptp_caps.verify = igc_ptp_verify_pin;
 
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c
index 65a94e46edcf..cec18efadc73 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c
@@ -643,13 +643,6 @@ static int mlx5_extts_configure(struct ptp_clock_info *ptp,
 	int pin = -1;
 	int err = 0;
 
-	/* Reject requests with unsupported flags */
-	if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
-				PTP_RISING_EDGE |
-				PTP_FALLING_EDGE |
-				PTP_STRICT_FLAGS))
-		return -EOPNOTSUPP;
-
 	/* Reject requests to enable time stamping on both edges. */
 	if ((rq->extts.flags & PTP_STRICT_FLAGS) &&
 	    (rq->extts.flags & PTP_ENABLE_FEATURE) &&
@@ -820,12 +813,6 @@ static int perout_conf_npps_real_time(struct mlx5_core_dev *mdev, struct ptp_clo
 	return 0;
 }
 
-static bool mlx5_perout_verify_flags(struct mlx5_core_dev *mdev, unsigned int flags)
-{
-	return ((!mlx5_npps_real_time_supported(mdev) && flags) ||
-		(mlx5_npps_real_time_supported(mdev) && flags & ~PTP_PEROUT_DUTY_CYCLE));
-}
-
 static int mlx5_perout_configure(struct ptp_clock_info *ptp,
 				 struct ptp_clock_request *rq,
 				 int on)
@@ -861,12 +848,6 @@ static int mlx5_perout_configure(struct ptp_clock_info *ptp,
 		goto unlock;
 	}
 
-	/* Reject requests with unsupported flags */
-	if (mlx5_perout_verify_flags(mdev, rq->perout.flags)) {
-		err = -EOPNOTSUPP;
-		goto unlock;
-	}
-
 	if (on) {
 		pin_mode = MLX5_PIN_MODE_OUT;
 		pattern = MLX5_OUT_PATTERN_PERIODIC;
@@ -1034,6 +1015,13 @@ static void mlx5_init_pin_config(struct mlx5_core_dev *mdev)
 	clock->ptp_info.verify = mlx5_ptp_verify;
 	clock->ptp_info.pps = 1;
 
+	clock->ptp_info.supported_extts_flags = PTP_RISING_EDGE |
+						PTP_FALLING_EDGE |
+						PTP_STRICT_FLAGS;
+
+	if (mlx5_npps_real_time_supported(mdev))
+		clock->ptp_info.supported_perout_flags = PTP_PEROUT_DUTY_CYCLE;
+
 	for (i = 0; i < clock->ptp_info.n_pins; i++) {
 		snprintf(clock->ptp_info.pin_config[i].name,
 			 sizeof(clock->ptp_info.pin_config[i].name),
diff --git a/drivers/net/ethernet/microchip/lan743x_ptp.c b/drivers/net/ethernet/microchip/lan743x_ptp.c
index 0be44dcb3393..b07f5b099a2b 100644
--- a/drivers/net/ethernet/microchip/lan743x_ptp.c
+++ b/drivers/net/ethernet/microchip/lan743x_ptp.c
@@ -463,10 +463,6 @@ static int lan743x_ptp_perout(struct lan743x_adapter *adapter, int on,
 	struct lan743x_ptp_perout *perout = &ptp->perout[index];
 	int ret = 0;
 
-	/* Reject requests with unsupported flags */
-	if (perout_request->flags & ~PTP_PEROUT_DUTY_CYCLE)
-		return -EOPNOTSUPP;
-
 	if (on) {
 		perout_pin = ptp_find_pin(ptp->ptp_clock, PTP_PF_PEROUT,
 					  perout_request->index);
@@ -942,12 +938,6 @@ static int lan743x_ptp_io_extts(struct lan743x_adapter *adapter, int on,
 
 	extts = &ptp->extts[index];
 
-	if (extts_request->flags & ~(PTP_ENABLE_FEATURE |
-				     PTP_RISING_EDGE |
-				     PTP_FALLING_EDGE |
-				     PTP_STRICT_FLAGS))
-		return -EOPNOTSUPP;
-
 	if (on) {
 		extts_pin = ptp_find_pin(ptp->ptp_clock, PTP_PF_EXTTS, index);
 		if (extts_pin < 0)
@@ -1543,6 +1533,10 @@ int lan743x_ptp_open(struct lan743x_adapter *adapter)
 	ptp->ptp_clock_info.n_per_out = LAN743X_PTP_N_EVENT_CHAN;
 	ptp->ptp_clock_info.n_pins = n_pins;
 	ptp->ptp_clock_info.pps = LAN743X_PTP_N_PPS;
+	ptp->ptp_clock_info.supported_extts_flags = PTP_RISING_EDGE |
+						    PTP_FALLING_EDGE |
+						    PTP_STRICT_FLAGS;
+	ptp->ptp_clock_info.supported_perout_flags = PTP_PEROUT_DUTY_CYCLE;
 	ptp->ptp_clock_info.pin_config = ptp->pin_config;
 	ptp->ptp_clock_info.adjfine = lan743x_ptpci_adjfine;
 	ptp->ptp_clock_info.adjtime = lan743x_ptpci_adjtime;
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_ptp.c b/drivers/net/ethernet/microchip/lan966x/lan966x_ptp.c
index 63905bb5a63a..098406e2e5bb 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_ptp.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_ptp.c
@@ -815,10 +815,6 @@ static int lan966x_ptp_perout(struct ptp_clock_info *ptp,
 	bool pps = false;
 	int pin;
 
-	if (rq->perout.flags & ~(PTP_PEROUT_DUTY_CYCLE |
-				 PTP_PEROUT_PHASE))
-		return -EOPNOTSUPP;
-
 	pin = ptp_find_pin(phc->clock, PTP_PF_PEROUT, rq->perout.index);
 	if (pin == -1 || pin >= LAN966X_PHC_PINS_NUM)
 		return -EINVAL;
@@ -917,12 +913,6 @@ static int lan966x_ptp_extts(struct ptp_clock_info *ptp,
 	if (lan966x->ptp_ext_irq <= 0)
 		return -EOPNOTSUPP;
 
-	/* Reject requests with unsupported flags */
-	if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
-				PTP_RISING_EDGE |
-				PTP_STRICT_FLAGS))
-		return -EOPNOTSUPP;
-
 	pin = ptp_find_pin(phc->clock, PTP_PF_EXTTS, rq->extts.index);
 	if (pin == -1 || pin >= LAN966X_PHC_PINS_NUM)
 		return -EINVAL;
@@ -978,6 +968,10 @@ static struct ptp_clock_info lan966x_ptp_clock_info = {
 	.n_per_out	= LAN966X_PHC_PINS_NUM,
 	.n_ext_ts	= LAN966X_PHC_PINS_NUM,
 	.n_pins		= LAN966X_PHC_PINS_NUM,
+	.supported_extts_flags = PTP_RISING_EDGE |
+				 PTP_STRICT_FLAGS,
+	.supported_perout_flags = PTP_PEROUT_DUTY_CYCLE |
+				  PTP_PEROUT_PHASE,
 };
 
 static int lan966x_ptp_phc_init(struct lan966x *lan966x,
diff --git a/drivers/net/ethernet/mscc/ocelot_ptp.c b/drivers/net/ethernet/mscc/ocelot_ptp.c
index cc1088988da0..d2a0a32f75ea 100644
--- a/drivers/net/ethernet/mscc/ocelot_ptp.c
+++ b/drivers/net/ethernet/mscc/ocelot_ptp.c
@@ -211,11 +211,6 @@ int ocelot_ptp_enable(struct ptp_clock_info *ptp,
 
 	switch (rq->type) {
 	case PTP_CLK_REQ_PEROUT:
-		/* Reject requests with unsupported flags */
-		if (rq->perout.flags & ~(PTP_PEROUT_DUTY_CYCLE |
-					 PTP_PEROUT_PHASE))
-			return -EOPNOTSUPP;
-
 		pin = ptp_find_pin(ocelot->ptp_clock, PTP_PF_PEROUT,
 				   rq->perout.index);
 		if (pin == 0)
diff --git a/drivers/net/ethernet/mscc/ocelot_vsc7514.c b/drivers/net/ethernet/mscc/ocelot_vsc7514.c
index 055b55651a49..498eec8ae61d 100644
--- a/drivers/net/ethernet/mscc/ocelot_vsc7514.c
+++ b/drivers/net/ethernet/mscc/ocelot_vsc7514.c
@@ -108,6 +108,8 @@ static struct ptp_clock_info ocelot_ptp_clock_info = {
 	.n_ext_ts	= 0,
 	.n_per_out	= OCELOT_PTP_PINS_NUM,
 	.n_pins		= OCELOT_PTP_PINS_NUM,
+	.supported_perout_flags = PTP_PEROUT_DUTY_CYCLE |
+				  PTP_PEROUT_PHASE,
 	.pps		= 0,
 	.gettime64	= ocelot_ptp_gettime64,
 	.settime64	= ocelot_ptp_settime64,
diff --git a/drivers/net/ethernet/renesas/ravb_ptp.c b/drivers/net/ethernet/renesas/ravb_ptp.c
index b4365906669f..226c6c0ab945 100644
--- a/drivers/net/ethernet/renesas/ravb_ptp.c
+++ b/drivers/net/ethernet/renesas/ravb_ptp.c
@@ -176,12 +176,6 @@ static int ravb_ptp_extts(struct ptp_clock_info *ptp,
 	struct net_device *ndev = priv->ndev;
 	unsigned long flags;
 
-	/* Reject requests with unsupported flags */
-	if (req->flags & ~(PTP_ENABLE_FEATURE |
-			   PTP_RISING_EDGE |
-			   PTP_FALLING_EDGE))
-		return -EOPNOTSUPP;
-
 	if (req->index)
 		return -EINVAL;
 
@@ -212,10 +206,6 @@ static int ravb_ptp_perout(struct ptp_clock_info *ptp,
 	unsigned long flags;
 	int error = 0;
 
-	/* Reject requests with unsupported flags */
-	if (req->flags)
-		return -EOPNOTSUPP;
-
 	if (req->index)
 		return -EINVAL;
 
@@ -287,6 +277,7 @@ static const struct ptp_clock_info ravb_ptp_info = {
 	.max_adj	= 50000000,
 	.n_ext_ts	= N_EXT_TS,
 	.n_per_out	= N_PER_OUT,
+	.supported_extts_flags = PTP_RISING_EDGE | PTP_FALLING_EDGE,
 	.adjfine	= ravb_ptp_adjfine,
 	.adjtime	= ravb_ptp_adjtime,
 	.gettime64	= ravb_ptp_gettime64,
diff --git a/drivers/net/phy/dp83640.c b/drivers/net/phy/dp83640.c
index 85e231451093..daab555721df 100644
--- a/drivers/net/phy/dp83640.c
+++ b/drivers/net/phy/dp83640.c
@@ -478,13 +478,6 @@ static int ptp_dp83640_enable(struct ptp_clock_info *ptp,
 
 	switch (rq->type) {
 	case PTP_CLK_REQ_EXTTS:
-		/* Reject requests with unsupported flags */
-		if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
-					PTP_RISING_EDGE |
-					PTP_FALLING_EDGE |
-					PTP_STRICT_FLAGS))
-			return -EOPNOTSUPP;
-
 		/* Reject requests to enable time stamping on both edges. */
 		if ((rq->extts.flags & PTP_STRICT_FLAGS) &&
 		    (rq->extts.flags & PTP_ENABLE_FEATURE) &&
@@ -513,9 +506,6 @@ static int ptp_dp83640_enable(struct ptp_clock_info *ptp,
 		return 0;
 
 	case PTP_CLK_REQ_PEROUT:
-		/* Reject requests with unsupported flags */
-		if (rq->perout.flags)
-			return -EOPNOTSUPP;
 		if (rq->perout.index >= N_PER_OUT)
 			return -EINVAL;
 		return periodic_output(clock, rq, on, rq->perout.index);
@@ -1002,6 +992,9 @@ static void dp83640_clock_init(struct dp83640_clock *clock, struct mii_bus *bus)
 	clock->caps.n_per_out	= N_PER_OUT;
 	clock->caps.n_pins	= DP83640_N_PINS;
 	clock->caps.pps		= 0;
+	clock->caps.supported_extts_flags = PTP_RISING_EDGE |
+					    PTP_FALLING_EDGE |
+					    PTP_STRICT_FLAGS;
 	clock->caps.adjfine	= ptp_dp83640_adjfine;
 	clock->caps.adjtime	= ptp_dp83640_adjtime;
 	clock->caps.gettime64	= ptp_dp83640_gettime;
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 24882d30f685..71fb4410c31b 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -3236,10 +3236,6 @@ static int lan8814_ptp_perout(struct ptp_clock_info *ptpci,
 	int pulse_width;
 	int pin, event;
 
-	/* Reject requests with unsupported flags */
-	if (rq->perout.flags & ~PTP_PEROUT_DUTY_CYCLE)
-		return -EOPNOTSUPP;
-
 	mutex_lock(&shared->shared_lock);
 	event = rq->perout.index;
 	pin = ptp_find_pin(shared->ptp_clock, PTP_PF_PEROUT, event);
@@ -3406,11 +3402,6 @@ static int lan8814_ptp_extts(struct ptp_clock_info *ptpci,
 	struct phy_device *phydev = shared->phydev;
 	int pin;
 
-	if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
-				PTP_EXTTS_EDGES |
-				PTP_STRICT_FLAGS))
-		return -EOPNOTSUPP;
-
 	pin = ptp_find_pin(shared->ptp_clock, PTP_PF_EXTTS,
 			   rq->extts.index);
 	if (pin == -1 || pin != LAN8814_PTP_EXTTS_NUM)
@@ -3917,6 +3908,10 @@ static int lan8814_ptp_probe_once(struct phy_device *phydev)
 	shared->ptp_clock_info.n_ext_ts = LAN8814_PTP_EXTTS_NUM;
 	shared->ptp_clock_info.n_pins = LAN8814_PTP_GPIO_NUM;
 	shared->ptp_clock_info.pps = 0;
+	shared->ptp_clock_info.supported_extts_flags = PTP_RISING_EDGE |
+						       PTP_FALLING_EDGE |
+						       PTP_STRICT_FLAGS;
+	shared->ptp_clock_info.supported_perout_flags = PTP_PEROUT_DUTY_CYCLE;
 	shared->ptp_clock_info.pin_config = shared->pin_config;
 	shared->ptp_clock_info.n_per_out = LAN8814_PTP_PEROUT_NUM;
 	shared->ptp_clock_info.adjfine = lan8814_ptpci_adjfine;
@@ -5068,9 +5063,6 @@ static int lan8841_ptp_perout(struct ptp_clock_info *ptp,
 	int pin;
 	int ret;
 
-	if (rq->perout.flags & ~PTP_PEROUT_DUTY_CYCLE)
-		return -EOPNOTSUPP;
-
 	pin = ptp_find_pin(ptp_priv->ptp_clock, PTP_PF_PEROUT, rq->perout.index);
 	if (pin == -1 || pin >= LAN8841_PTP_GPIO_NUM)
 		return -EINVAL;
@@ -5314,6 +5306,7 @@ static struct ptp_clock_info lan8841_ptp_clock_info = {
 	.n_per_out      = LAN8841_PTP_GPIO_NUM,
 	.n_ext_ts       = LAN8841_PTP_GPIO_NUM,
 	.n_pins         = LAN8841_PTP_GPIO_NUM,
+	.supported_perout_flags = PTP_PEROUT_DUTY_CYCLE,
 };
 
 #define LAN8841_OPERATION_MODE_STRAP_LOW_REGISTER 3
diff --git a/drivers/net/phy/microchip_rds_ptp.c b/drivers/net/phy/microchip_rds_ptp.c
index 3e6bf10cdeed..e6514ce04c29 100644
--- a/drivers/net/phy/microchip_rds_ptp.c
+++ b/drivers/net/phy/microchip_rds_ptp.c
@@ -224,10 +224,6 @@ static int mchp_rds_ptp_perout(struct ptp_clock_info *ptpci,
 	struct phy_device *phydev = clock->phydev;
 	int ret, event_pin, pulsewidth;
 
-	/* Reject requests with unsupported flags */
-	if (perout->flags & ~PTP_PEROUT_DUTY_CYCLE)
-		return -EOPNOTSUPP;
-
 	event_pin = ptp_find_pin(clock->ptp_clock, PTP_PF_PEROUT,
 				 perout->index);
 	if (event_pin != clock->event_pin)
@@ -1259,6 +1255,7 @@ struct mchp_rds_ptp_clock *mchp_rds_ptp_probe(struct phy_device *phydev, u8 mmd,
 	clock->caps.pps            = 0;
 	clock->caps.n_pins         = MCHP_RDS_PTP_N_PIN;
 	clock->caps.n_per_out      = MCHP_RDS_PTP_N_PEROUT;
+	clock->caps.supported_perout_flags = PTP_PEROUT_DUTY_CYCLE;
 	clock->caps.pin_config     = clock->pin_config;
 	clock->caps.adjfine        = mchp_rds_ptp_ltc_adjfine;
 	clock->caps.adjtime        = mchp_rds_ptp_ltc_adjtime;
diff --git a/drivers/net/phy/nxp-c45-tja11xx.c b/drivers/net/phy/nxp-c45-tja11xx.c
index 250a018d5546..f11dd32494c3 100644
--- a/drivers/net/phy/nxp-c45-tja11xx.c
+++ b/drivers/net/phy/nxp-c45-tja11xx.c
@@ -763,9 +763,6 @@ static int nxp_c45_perout_enable(struct nxp_c45_phy *priv,
 	struct phy_device *phydev = priv->phydev;
 	int pin;
 
-	if (perout->flags & ~PTP_PEROUT_PHASE)
-		return -EOPNOTSUPP;
-
 	pin = ptp_find_pin(priv->ptp_clock, PTP_PF_PEROUT, perout->index);
 	if (pin < 0)
 		return pin;
@@ -861,12 +858,6 @@ static int nxp_c45_extts_enable(struct nxp_c45_phy *priv,
 	const struct nxp_c45_phy_data *data = nxp_c45_get_data(priv->phydev);
 	int pin;
 
-	if (extts->flags & ~(PTP_ENABLE_FEATURE |
-			      PTP_RISING_EDGE |
-			      PTP_FALLING_EDGE |
-			      PTP_STRICT_FLAGS))
-		return -EOPNOTSUPP;
-
 	/* Sampling on both edges is not supported */
 	if ((extts->flags & PTP_RISING_EDGE) &&
 	    (extts->flags & PTP_FALLING_EDGE) &&
@@ -962,6 +953,10 @@ static int nxp_c45_init_ptp_clock(struct nxp_c45_phy *priv)
 		.n_pins		= ARRAY_SIZE(nxp_c45_ptp_pins),
 		.n_ext_ts	= 1,
 		.n_per_out	= 1,
+		.supported_extts_flags = PTP_RISING_EDGE |
+					 PTP_FALLING_EDGE |
+					 PTP_STRICT_FLAGS,
+		.supported_perout_flags = PTP_PEROUT_PHASE,
 	};
 
 	priv->ptp_clock = ptp_clock_register(&priv->caps,
diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 4380e6ddb849..4bf421765d03 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -162,6 +162,7 @@ long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
 {
 	struct ptp_clock *ptp =
 		container_of(pccontext->clk, struct ptp_clock, clock);
+	unsigned int i, pin_index, supported_extts_flags;
 	struct ptp_sys_offset_extended *extoff = NULL;
 	struct ptp_sys_offset_precise precise_offset;
 	struct system_device_crosststamp xtstamp;
@@ -172,7 +173,6 @@ long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
 	struct ptp_clock_request req;
 	struct ptp_clock_caps caps;
 	struct ptp_clock_time *pct;
-	unsigned int i, pin_index;
 	struct ptp_pin_desc pd;
 	struct timespec64 ts;
 	int enable, err = 0;
@@ -240,6 +240,18 @@ long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
 			err = -EINVAL;
 			break;
 		}
+		supported_extts_flags = ptp->info->supported_extts_flags;
+		/* The PTP_ENABLE_FEATURE flag is always supported. */
+		supported_extts_flags |= PTP_ENABLE_FEATURE;
+		/* If the driver does not support strictly checking flags, the
+		 * PTP_RISING_EDGE and PTP_FALLING_EDGE flags are merely
+		 * hints which are not enforced.
+		 */
+		if (!(supported_extts_flags & PTP_STRICT_FLAGS))
+			supported_extts_flags |= PTP_EXTTS_EDGES;
+		/* Reject unsupported flags */
+		if (req.extts.flags & ~supported_extts_flags)
+			return -EOPNOTSUPP;
 		req.type = PTP_CLK_REQ_EXTTS;
 		enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
@@ -312,6 +324,8 @@ long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
 			err = -EINVAL;
 			break;
 		}
+		if (req.perout.flags & ~ptp->info->supported_perout_flags)
+			return -EOPNOTSUPP;
 		req.type = PTP_CLK_REQ_PEROUT;
 		enable = req.perout.period.sec || req.perout.period.nsec;
 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
diff --git a/drivers/ptp/ptp_clockmatrix.c b/drivers/ptp/ptp_clockmatrix.c
index fbb3fa8fc60b..b8d4df8c6da2 100644
--- a/drivers/ptp/ptp_clockmatrix.c
+++ b/drivers/ptp/ptp_clockmatrix.c
@@ -283,18 +283,6 @@ static int idtcm_extts_enable(struct idtcm_channel *channel,
 	idtcm = channel->idtcm;
 	old_mask = idtcm->extts_mask;
 
-	/* Reject requests with unsupported flags */
-	if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
-				PTP_RISING_EDGE |
-				PTP_FALLING_EDGE |
-				PTP_STRICT_FLAGS))
-		return -EOPNOTSUPP;
-
-	/* Reject requests to enable time stamping on falling edge */
-	if ((rq->extts.flags & PTP_ENABLE_FEATURE) &&
-	    (rq->extts.flags & PTP_FALLING_EDGE))
-		return -EOPNOTSUPP;
-
 	if (index >= MAX_TOD)
 		return -EINVAL;
 
@@ -2043,6 +2031,7 @@ static const struct ptp_clock_info idtcm_caps = {
 	.n_per_out	= 12,
 	.n_ext_ts	= MAX_TOD,
 	.n_pins		= MAX_REF_CLK,
+	.supported_extts_flags = PTP_RISING_EDGE | PTP_STRICT_FLAGS,
 	.adjphase	= &idtcm_adjphase,
 	.getmaxphase	= &idtcm_getmaxphase,
 	.adjfine	= &idtcm_adjfine,
@@ -2060,6 +2049,7 @@ static const struct ptp_clock_info idtcm_caps_deprecated = {
 	.n_per_out	= 12,
 	.n_ext_ts	= MAX_TOD,
 	.n_pins		= MAX_REF_CLK,
+	.supported_extts_flags = PTP_RISING_EDGE | PTP_STRICT_FLAGS,
 	.adjphase	= &idtcm_adjphase,
 	.getmaxphase    = &idtcm_getmaxphase,
 	.adjfine	= &idtcm_adjfine,
diff --git a/drivers/ptp/ptp_fc3.c b/drivers/ptp/ptp_fc3.c
index cfced36c70bc..70002500170e 100644
--- a/drivers/ptp/ptp_fc3.c
+++ b/drivers/ptp/ptp_fc3.c
@@ -592,6 +592,7 @@ static const struct ptp_clock_info idtfc3_caps = {
 	.max_adj	= MAX_FFO_PPB,
 	.n_per_out	= 1,
 	.n_ext_ts	= 1,
+	.supported_extts_flags = PTP_STRICT_FLAGS | PTP_EXT_OFFSET,
 	.adjphase	= &idtfc3_adjphase,
 	.adjfine	= &idtfc3_adjfine,
 	.adjtime	= &idtfc3_adjtime,
diff --git a/drivers/ptp/ptp_idt82p33.c b/drivers/ptp/ptp_idt82p33.c
index b2fd94d4f863..f01c50dfa44e 100644
--- a/drivers/ptp/ptp_idt82p33.c
+++ b/drivers/ptp/ptp_idt82p33.c
@@ -246,18 +246,6 @@ static int idt82p33_extts_enable(struct idt82p33_channel *channel,
 	idt82p33  = channel->idt82p33;
 	old_mask = idt82p33->extts_mask;
 
-	/* Reject requests with unsupported flags */
-	if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
-				PTP_RISING_EDGE |
-				PTP_FALLING_EDGE |
-				PTP_STRICT_FLAGS))
-		return -EOPNOTSUPP;
-
-	/* Reject requests to enable time stamping on falling edge */
-	if ((rq->extts.flags & PTP_ENABLE_FEATURE) &&
-	    (rq->extts.flags & PTP_FALLING_EDGE))
-		return -EOPNOTSUPP;
-
 	if (index >= MAX_PHC_PLL)
 		return -EINVAL;
 
@@ -1187,6 +1175,9 @@ static void idt82p33_caps_init(u32 index, struct ptp_clock_info *caps,
 
 	caps->pin_config = pin_cfg;
 
+	caps->supported_extts_flags = PTP_RISING_EDGE |
+				      PTP_STRICT_FLAGS;
+
 	for (i = 0; i < max_pins; ++i) {
 		ppd = &pin_cfg[i];
 
diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h
index 0d68d09bedd1..eced7e9bf69a 100644
--- a/include/linux/ptp_clock_kernel.h
+++ b/include/linux/ptp_clock_kernel.h
@@ -68,6 +68,22 @@ struct ptp_system_timestamp {
  * @n_per_out: The number of programmable periodic signals.
  * @n_pins:    The number of programmable pins.
  * @pps:       Indicates whether the clock supports a PPS callback.
+ *
+ * @supported_perout_flags:  The set of flags the driver supports for the
+ *                           PTP_PEROUT_REQUEST ioctl. The PTP core will
+ *                           reject a request with any flag not specified
+ *                           here.
+ *
+ * @supported_extts_flags:  The set of flags the driver supports for the
+ *                          PTP_EXTTS_REQUEST ioctl. The PTP core will use
+ *                          this list to reject unsupported requests.
+ *                          PTP_ENABLE_FEATURE is assumed and does not need to
+ *                          be included. If PTP_STRICT_FLAGS is *not* set,
+ *                          then both PTP_RISING_EDGE and PTP_FALLING_EDGE
+ *                          will be assumed. Note that PTP_STRICT_FLAGS must
+ *                          be set if the drivers wants to honor
+ *                          PTP_EXTTS_REQUEST2 and any future flags.
+ *
  * @pin_config: Array of length 'n_pins'. If the number of
  *              programmable pins is nonzero, then drivers must
  *              allocate and initialize this array.
@@ -174,6 +190,8 @@ struct ptp_clock_info {
 	int n_per_out;
 	int n_pins;
 	int pps;
+	unsigned int supported_perout_flags;
+	unsigned int supported_extts_flags;
 	struct ptp_pin_desc *pin_config;
 	int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);
 	int (*adjphase)(struct ptp_clock_info *ptp, s32 phase);