Merge branch '1GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/next-queue

Jeff Kirsher says:

====================
1GbE Intel Wired LAN Driver Updates 2020-01-06

This series contains updates to igc to add basic support for
timestamping.

Vinicius adds basic support for timestamping and enables ptp4l/phc2sys
to work with i225 devices.  Initially, adds the ability to read and
adjust the PHC clock.  Patches 2 & 3 enable and retrieve hardware
timestamps.  Patch 4 implements the ethtool ioctl that ptp4l uses to
check what timestamping methods are supported.  Lastly, added support to
do timestamping using the "Start of Packet" signal from the PHY, which
is now supported in i225 devices.

While i225 does support multiple PTP domains, with multiple timestamping
registers, we currently only support one PTP domain and use only one of
the timestamping registers for implementation purposes.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/intel/igc/Makefile

@@ -8,4 +8,4 @@
 obj-$(CONFIG_IGC) += igc.o
 
 igc-objs := igc_main.o igc_mac.o igc_i225.o igc_base.o igc_nvm.o igc_phy.o \
-igc_ethtool.o
+igc_ethtool.o igc_ptp.o

drivers/net/ethernet/intel/igc/igc.h

@@ -10,6 +10,9 @@
 #include <linux/vmalloc.h>
 #include <linux/ethtool.h>
 #include <linux/sctp.h>
+#include <linux/ptp_clock_kernel.h>
+#include <linux/timecounter.h>
+#include <linux/net_tstamp.h>
 
 #include "igc_hw.h"
 
@@ -45,11 +48,15 @@ extern char igc_driver_version[];
 #define IGC_REGS_LEN			740
 #define IGC_RETA_SIZE			128
 
+/* flags controlling PTP/1588 function */
+#define IGC_PTP_ENABLED		BIT(0)
+
 /* Interrupt defines */
 #define IGC_START_ITR			648 /* ~6000 ints/sec */
 #define IGC_FLAG_HAS_MSI		BIT(0)
 #define IGC_FLAG_QUEUE_PAIRS		BIT(3)
 #define IGC_FLAG_DMAC			BIT(4)
+#define IGC_FLAG_PTP			BIT(8)
 #define IGC_FLAG_NEED_LINK_UPDATE	BIT(9)
 #define IGC_FLAG_MEDIA_RESET		BIT(10)
 #define IGC_FLAG_MAS_ENABLE		BIT(12)
@@ -100,6 +107,20 @@ extern char igc_driver_version[];
 #define AUTO_ALL_MODES		0
 #define IGC_RX_HDR_LEN			IGC_RXBUFFER_256
 
+/* Transmit and receive latency (for PTP timestamps) */
+/* FIXME: These values were estimated using the ones that i210 has as
+ * basis, they seem to provide good numbers with ptp4l/phc2sys, but we
+ * need to confirm them.
+ */
+#define IGC_I225_TX_LATENCY_10		9542
+#define IGC_I225_TX_LATENCY_100		1024
+#define IGC_I225_TX_LATENCY_1000	178
+#define IGC_I225_TX_LATENCY_2500	64
+#define IGC_I225_RX_LATENCY_10		20662
+#define IGC_I225_RX_LATENCY_100		2213
+#define IGC_I225_RX_LATENCY_1000	448
+#define IGC_I225_RX_LATENCY_2500	160
+
 /* RX and TX descriptor control thresholds.
  * PTHRESH - MAC will consider prefetch if it has fewer than this number of
  *           descriptors available in its onboard memory.
@@ -432,6 +453,20 @@ struct igc_adapter {
 
 	unsigned long link_check_timeout;
 	struct igc_info ei;
+
+	struct ptp_clock *ptp_clock;
+	struct ptp_clock_info ptp_caps;
+	struct work_struct ptp_tx_work;
+	struct sk_buff *ptp_tx_skb;
+	struct hwtstamp_config tstamp_config;
+	unsigned long ptp_tx_start;
+	unsigned long last_rx_ptp_check;
+	unsigned long last_rx_timestamp;
+	unsigned int ptp_flags;
+	/* System time value lock */
+	spinlock_t tmreg_lock;
+	struct cyclecounter cc;
+	struct timecounter tc;
 };
 
 /* igc_desc_unused - calculate if we have unused descriptors */
@@ -515,6 +550,16 @@ int igc_add_filter(struct igc_adapter *adapter,
 int igc_erase_filter(struct igc_adapter *adapter,
 		     struct igc_nfc_filter *input);
 
+void igc_ptp_init(struct igc_adapter *adapter);
+void igc_ptp_reset(struct igc_adapter *adapter);
+void igc_ptp_stop(struct igc_adapter *adapter);
+void igc_ptp_rx_rgtstamp(struct igc_q_vector *q_vector, struct sk_buff *skb);
+void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, void *va,
+			 struct sk_buff *skb);
+int igc_ptp_set_ts_config(struct net_device *netdev, struct ifreq *ifr);
+int igc_ptp_get_ts_config(struct net_device *netdev, struct ifreq *ifr);
+void igc_ptp_tx_hang(struct igc_adapter *adapter);
+
 #define igc_rx_pg_size(_ring) (PAGE_SIZE << igc_rx_pg_order(_ring))
 
 #define IGC_TXD_DCMD	(IGC_ADVTXD_DCMD_EOP | IGC_ADVTXD_DCMD_RS)

drivers/net/ethernet/intel/igc/igc_defines.h

@@ -218,6 +218,7 @@
 #define IGC_ICR_RXDMT0		BIT(4)	/* Rx desc min. threshold (0) */
 #define IGC_ICR_RXO		BIT(6)	/* Rx overrun */
 #define IGC_ICR_RXT0		BIT(7)	/* Rx timer intr (ring 0) */
+#define IGC_ICR_TS		BIT(19)	/* Time Sync Interrupt */
 #define IGC_ICR_DRSTA		BIT(30)	/* Device Reset Asserted */
 
 /* If this bit asserted, the driver should claim the interrupt */
@@ -240,6 +241,7 @@
 #define IGC_IMS_DRSTA		IGC_ICR_DRSTA	/* Device Reset Asserted */
 #define IGC_IMS_RXT0		IGC_ICR_RXT0	/* Rx timer intr */
 #define IGC_IMS_RXDMT0		IGC_ICR_RXDMT0	/* Rx desc min. threshold */
+#define IGC_IMS_TS		IGC_ICR_TS	/* Time Sync Interrupt */
 
 #define IGC_QVECTOR_MASK	0x7FFC		/* Q-vector mask */
 #define IGC_ITR_VAL_MASK	0x04		/* ITR value mask */
@@ -312,12 +314,21 @@
 #define IGC_RCTL_RDMTS_HALF	0x00000000 /* Rx desc min thresh size */
 #define IGC_RCTL_BAM		0x00008000 /* broadcast enable */
 
+/* Split Replication Receive Control */
+#define IGC_SRRCTL_TIMESTAMP		0x40000000
+#define IGC_SRRCTL_TIMER1SEL(timer)	(((timer) & 0x3) << 14)
+#define IGC_SRRCTL_TIMER0SEL(timer)	(((timer) & 0x3) << 17)
+
 /* Receive Descriptor bit definitions */
 #define IGC_RXD_STAT_EOP	0x02	/* End of Packet */
 #define IGC_RXD_STAT_IXSM	0x04	/* Ignore checksum */
 #define IGC_RXD_STAT_UDPCS	0x10	/* UDP xsum calculated */
 #define IGC_RXD_STAT_TCPCS	0x20	/* TCP xsum calculated */
 
+/* Advanced Receive Descriptor bit definitions */
+#define IGC_RXDADV_STAT_TSIP	0x08000 /* timestamp in packet */
+#define IGC_RXDADV_STAT_TS	0x10000 /* Pkt was time stamped */
+
 #define IGC_RXDEXT_STATERR_CE		0x01000000
 #define IGC_RXDEXT_STATERR_SE		0x02000000
 #define IGC_RXDEXT_STATERR_SEQ		0x04000000
@@ -354,6 +365,61 @@
 
 #define I225_RXPBSIZE_DEFAULT	0x000000A2 /* RXPBSIZE default */
 #define I225_TXPBSIZE_DEFAULT	0x04000014 /* TXPBSIZE default */
+#define IGC_RXPBS_CFG_TS_EN	0x80000000 /* Timestamp in Rx buffer */
+
+/* Time Sync Interrupt Causes */
+#define IGC_TSICR_SYS_WRAP	BIT(0) /* SYSTIM Wrap around. */
+#define IGC_TSICR_TXTS		BIT(1) /* Transmit Timestamp. */
+#define IGC_TSICR_TT0		BIT(3) /* Target Time 0 Trigger. */
+#define IGC_TSICR_TT1		BIT(4) /* Target Time 1 Trigger. */
+#define IGC_TSICR_AUTT0		BIT(5) /* Auxiliary Timestamp 0 Taken. */
+#define IGC_TSICR_AUTT1		BIT(6) /* Auxiliary Timestamp 1 Taken. */
+
+#define IGC_TSICR_INTERRUPTS	IGC_TSICR_TXTS
+
+/* PTP Queue Filter */
+#define IGC_ETQF_1588		BIT(30)
+
+#define IGC_FTQF_VF_BP		0x00008000
+#define IGC_FTQF_1588_TIME_STAMP	0x08000000
+#define IGC_FTQF_MASK			0xF0000000
+#define IGC_FTQF_MASK_PROTO_BP	0x10000000
+
+/* Time Sync Receive Control bit definitions */
+#define IGC_TSYNCRXCTL_VALID		0x00000001  /* Rx timestamp valid */
+#define IGC_TSYNCRXCTL_TYPE_MASK	0x0000000E  /* Rx type mask */
+#define IGC_TSYNCRXCTL_TYPE_L2_V2	0x00
+#define IGC_TSYNCRXCTL_TYPE_L4_V1	0x02
+#define IGC_TSYNCRXCTL_TYPE_L2_L4_V2	0x04
+#define IGC_TSYNCRXCTL_TYPE_ALL		0x08
+#define IGC_TSYNCRXCTL_TYPE_EVENT_V2	0x0A
+#define IGC_TSYNCRXCTL_ENABLED		0x00000010  /* enable Rx timestamping */
+#define IGC_TSYNCRXCTL_SYSCFI		0x00000020  /* Sys clock frequency */
+#define IGC_TSYNCRXCTL_RXSYNSIG		0x00000400  /* Sample RX tstamp in PHY sop */
+
+/* Time Sync Receive Configuration */
+#define IGC_TSYNCRXCFG_PTP_V1_CTRLT_MASK	0x000000FF
+#define IGC_TSYNCRXCFG_PTP_V1_SYNC_MESSAGE	0x00
+#define IGC_TSYNCRXCFG_PTP_V1_DELAY_REQ_MESSAGE	0x01
+
+/* Immediate Interrupt Receive */
+#define IGC_IMIR_CLEAR_MASK	0xF001FFFF /* IMIR Reg Clear Mask */
+#define IGC_IMIR_PORT_BYPASS	0x20000 /* IMIR Port Bypass Bit */
+#define IGC_IMIR_PRIORITY_SHIFT	29 /* IMIR Priority Shift */
+#define IGC_IMIREXT_CLEAR_MASK	0x7FFFF /* IMIREXT Reg Clear Mask */
+
+/* Immediate Interrupt Receive Extended */
+#define IGC_IMIREXT_CTRL_BP	0x00080000  /* Bypass check of ctrl bits */
+#define IGC_IMIREXT_SIZE_BP	0x00001000  /* Packet size bypass */
+
+/* Time Sync Transmit Control bit definitions */
+#define IGC_TSYNCTXCTL_VALID			0x00000001  /* Tx timestamp valid */
+#define IGC_TSYNCTXCTL_ENABLED			0x00000010  /* enable Tx timestamping */
+#define IGC_TSYNCTXCTL_MAX_ALLOWED_DLY_MASK	0x0000F000  /* max delay */
+#define IGC_TSYNCTXCTL_SYNC_COMP_ERR		0x20000000  /* sync err */
+#define IGC_TSYNCTXCTL_SYNC_COMP		0x40000000  /* sync complete */
+#define IGC_TSYNCTXCTL_START_SYNC		0x80000000  /* initiate sync */
+#define IGC_TSYNCTXCTL_TXSYNSIG			0x00000020  /* Sample TX tstamp in PHY sop */
 
 /* Receive Checksum Control */
 #define IGC_RXCSUM_CRCOFL	0x00000800   /* CRC32 offload enable */

drivers/net/ethernet/intel/igc/igc_ethtool.c

@@ -1600,6 +1600,39 @@ static int igc_set_channels(struct net_device *netdev,
 	return 0;
 }
 
+static int igc_get_ts_info(struct net_device *dev,
+			   struct ethtool_ts_info *info)
+{
+	struct igc_adapter *adapter = netdev_priv(dev);
+
+	if (adapter->ptp_clock)
+		info->phc_index = ptp_clock_index(adapter->ptp_clock);
+	else
+		info->phc_index = -1;
+
+	switch (adapter->hw.mac.type) {
+	case igc_i225:
+		info->so_timestamping =
+			SOF_TIMESTAMPING_TX_SOFTWARE |
+			SOF_TIMESTAMPING_RX_SOFTWARE |
+			SOF_TIMESTAMPING_SOFTWARE |
+			SOF_TIMESTAMPING_TX_HARDWARE |
+			SOF_TIMESTAMPING_RX_HARDWARE |
+			SOF_TIMESTAMPING_RAW_HARDWARE;
+
+		info->tx_types =
+			BIT(HWTSTAMP_TX_OFF) |
+			BIT(HWTSTAMP_TX_ON);
+
+		info->rx_filters = BIT(HWTSTAMP_FILTER_NONE);
+		info->rx_filters |= BIT(HWTSTAMP_FILTER_ALL);
+
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 static u32 igc_get_priv_flags(struct net_device *netdev)
 {
 	struct igc_adapter *adapter = netdev_priv(netdev);
@@ -1847,6 +1880,7 @@ static const struct ethtool_ops igc_ethtool_ops = {
 	.get_rxfh_indir_size	= igc_get_rxfh_indir_size,
 	.get_rxfh		= igc_get_rxfh,
 	.set_rxfh		= igc_set_rxfh,
+	.get_ts_info		= igc_get_ts_info,
 	.get_channels		= igc_get_channels,
 	.set_channels		= igc_set_channels,
 	.get_priv_flags		= igc_get_priv_flags,

drivers/net/ethernet/intel/igc/igc_main.c

@@ -102,6 +102,9 @@ void igc_reset(struct igc_adapter *adapter)
 	if (!netif_running(adapter->netdev))
 		igc_power_down_link(adapter);
 
+	/* Re-enable PTP, where applicable. */
+	igc_ptp_reset(adapter);
+
 	igc_get_phy_info(hw);
 }
 
@@ -984,6 +987,11 @@ static inline int igc_maybe_stop_tx(struct igc_ring *tx_ring, const u16 size)
 	return __igc_maybe_stop_tx(tx_ring, size);
 }
 
+#define IGC_SET_FLAG(_input, _flag, _result) \
+	(((_flag) <= (_result)) ?				\
+	 ((u32)((_input) & (_flag)) * ((_result) / (_flag))) :	\
+	 ((u32)((_input) & (_flag)) / ((_flag) / (_result))))
+
 static u32 igc_tx_cmd_type(struct sk_buff *skb, u32 tx_flags)
 {
 	/* set type for advanced descriptor with frame checksum insertion */
@@ -991,6 +999,10 @@ static u32 igc_tx_cmd_type(struct sk_buff *skb, u32 tx_flags)
 		       IGC_ADVTXD_DCMD_DEXT |
 		       IGC_ADVTXD_DCMD_IFCS;
 
+	/* set timestamp bit if present */
+	cmd_type |= IGC_SET_FLAG(tx_flags, IGC_TX_FLAGS_TSTAMP,
+				 (IGC_ADVTXD_MAC_TSTAMP));
+
 	return cmd_type;
 }
 
@@ -1189,6 +1201,26 @@ static netdev_tx_t igc_xmit_frame_ring(struct sk_buff *skb,
 	first->bytecount = skb->len;
 	first->gso_segs = 1;
 
+	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) {
+		struct igc_adapter *adapter = netdev_priv(tx_ring->netdev);
+
+		/* FIXME: add support for retrieving timestamps from
+		 * the other timer registers before skipping the
+		 * timestamping request.
+		 */
+		if (adapter->tstamp_config.tx_type == HWTSTAMP_TX_ON &&
+		    !test_and_set_bit_lock(__IGC_PTP_TX_IN_PROGRESS,
+					   &adapter->state)) {
+			skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
+			tx_flags |= IGC_TX_FLAGS_TSTAMP;
+
+			adapter->ptp_tx_skb = skb_get(skb);
+			adapter->ptp_tx_start = jiffies;
+		} else {
+			adapter->tx_hwtstamp_skipped++;
+		}
+	}
+
 	/* record initial flags and protocol */
 	first->tx_flags = tx_flags;
 	first->protocol = protocol;
@@ -1296,6 +1328,10 @@ static void igc_process_skb_fields(struct igc_ring *rx_ring,
 
 	igc_rx_checksum(rx_ring, rx_desc, skb);
 
+	if (igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TS) &&
+	    !igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TSIP))
+		igc_ptp_rx_rgtstamp(rx_ring->q_vector, skb);
+
 	skb_record_rx_queue(skb, rx_ring->queue_index);
 
 	skb->protocol = eth_type_trans(skb, rx_ring->netdev);
@@ -1415,6 +1451,12 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring,
 	if (unlikely(!skb))
 		return NULL;
 
+	if (unlikely(igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TSIP))) {
+		igc_ptp_rx_pktstamp(rx_ring->q_vector, va, skb);
+		va += IGC_TS_HDR_LEN;
+		size -= IGC_TS_HDR_LEN;
+	}
+
 	/* Determine available headroom for copy */
 	headlen = size;
 	if (headlen > IGC_RX_HDR_LEN)
@@ -3635,6 +3677,22 @@ int igc_del_mac_steering_filter(struct igc_adapter *adapter,
 					IGC_MAC_STATE_QUEUE_STEERING | flags);
 }
 
+static void igc_tsync_interrupt(struct igc_adapter *adapter)
+{
+	struct igc_hw *hw = &adapter->hw;
+	u32 tsicr = rd32(IGC_TSICR);
+	u32 ack = 0;
+
+	if (tsicr & IGC_TSICR_TXTS) {
+		/* retrieve hardware timestamp */
+		schedule_work(&adapter->ptp_tx_work);
+		ack |= IGC_TSICR_TXTS;
+	}
+
+	/* acknowledge the interrupts */
+	wr32(IGC_TSICR, ack);
+}
+
 /**
  * igc_msix_other - msix other interrupt handler
  * @irq: interrupt number
@@ -3662,6 +3720,9 @@ static irqreturn_t igc_msix_other(int irq, void *data)
 			mod_timer(&adapter->watchdog_timer, jiffies + 1);
 	}
 
+	if (icr & IGC_ICR_TS)
+		igc_tsync_interrupt(adapter);
+
 	wr32(IGC_EIMS, adapter->eims_other);
 
 	return IRQ_HANDLED;
@@ -3991,6 +4052,8 @@ static void igc_watchdog_task(struct work_struct *work)
 		wr32(IGC_ICS, IGC_ICS_RXDMT0);
 	}
 
+	igc_ptp_tx_hang(adapter);
+
 	/* Reset the timer */
 	if (!test_bit(__IGC_DOWN, &adapter->state)) {
 		if (adapter->flags & IGC_FLAG_NEED_LINK_UPDATE)
@@ -4277,6 +4340,24 @@ static int igc_close(struct net_device *netdev)
 	return 0;
 }
 
+/**
+ * igc_ioctl - Access the hwtstamp interface
+ * @netdev: network interface device structure
+ * @ifreq: interface request data
+ * @cmd: ioctl command
+ **/
+static int igc_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
+{
+	switch (cmd) {
+	case SIOCGHWTSTAMP:
+		return igc_ptp_get_ts_config(netdev, ifr);
+	case SIOCSHWTSTAMP:
+		return igc_ptp_set_ts_config(netdev, ifr);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 static const struct net_device_ops igc_netdev_ops = {
 	.ndo_open		= igc_open,
 	.ndo_stop		= igc_close,
@@ -4288,6 +4369,7 @@ static const struct net_device_ops igc_netdev_ops = {
 	.ndo_fix_features	= igc_fix_features,
 	.ndo_set_features	= igc_set_features,
 	.ndo_features_check	= igc_features_check,
+	.ndo_do_ioctl		= igc_ioctl,
 };
 
 /* PCIe configuration access */
@@ -4588,6 +4670,9 @@ static int igc_probe(struct pci_dev *pdev,
 	 /* carrier off reporting is important to ethtool even BEFORE open */
 	netif_carrier_off(netdev);
 
+	/* do hw tstamp init after resetting */
+	igc_ptp_init(adapter);
+
 	/* Check if Media Autosense is enabled */
 	adapter->ei = *ei;
 
@@ -4629,6 +4714,8 @@ static void igc_remove(struct pci_dev *pdev)
 	struct net_device *netdev = pci_get_drvdata(pdev);
 	struct igc_adapter *adapter = netdev_priv(netdev);
 
+	igc_ptp_stop(adapter);
+
 	set_bit(__IGC_DOWN, &adapter->state);
 
 	del_timer_sync(&adapter->watchdog_timer);

drivers/net/ethernet/intel/igc/igc_ptp.c

+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c)  2019 Intel Corporation */
+
+#include "igc.h"
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/pci.h>
+#include <linux/ptp_classify.h>
+#include <linux/clocksource.h>
+
+#define INCVALUE_MASK		0x7fffffff
+#define ISGN			0x80000000
+
+#define IGC_SYSTIM_OVERFLOW_PERIOD	(HZ * 60 * 9)
+#define IGC_PTP_TX_TIMEOUT		(HZ * 15)
+
+/* SYSTIM read access for I225 */
+static void igc_ptp_read_i225(struct igc_adapter *adapter,
+			      struct timespec64 *ts)
+{
+	struct igc_hw *hw = &adapter->hw;
+	u32 sec, nsec;
+
+	/* The timestamp latches on lowest register read. For I210/I211, the
+	 * lowest register is SYSTIMR. Since we only need to provide nanosecond
+	 * resolution, we can ignore it.
+	 */
+	rd32(IGC_SYSTIMR);
+	nsec = rd32(IGC_SYSTIML);
+	sec = rd32(IGC_SYSTIMH);
+
+	ts->tv_sec = sec;
+	ts->tv_nsec = nsec;
+}
+
+static void igc_ptp_write_i225(struct igc_adapter *adapter,
+			       const struct timespec64 *ts)
+{
+	struct igc_hw *hw = &adapter->hw;
+
+	/* Writing the SYSTIMR register is not necessary as it only
+	 * provides sub-nanosecond resolution.
+	 */
+	wr32(IGC_SYSTIML, ts->tv_nsec);
+	wr32(IGC_SYSTIMH, ts->tv_sec);
+}
+
+static int igc_ptp_adjfine_i225(struct ptp_clock_info *ptp, long scaled_ppm)
+{
+	struct igc_adapter *igc = container_of(ptp, struct igc_adapter,
+					       ptp_caps);
+	struct igc_hw *hw = &igc->hw;
+	int neg_adj = 0;
+	u64 rate;
+	u32 inca;
+
+	if (scaled_ppm < 0) {
+		neg_adj = 1;
+		scaled_ppm = -scaled_ppm;
+	}
+	rate = scaled_ppm;
+	rate <<= 14;
+	rate = div_u64(rate, 78125);
+
+	inca = rate & INCVALUE_MASK;
+	if (neg_adj)
+		inca |= ISGN;
+
+	wr32(IGC_TIMINCA, inca);
+
+	return 0;
+}
+
+static int igc_ptp_adjtime_i225(struct ptp_clock_info *ptp, s64 delta)
+{
+	struct igc_adapter *igc = container_of(ptp, struct igc_adapter,
+					       ptp_caps);
+	struct timespec64 now, then = ns_to_timespec64(delta);
+	unsigned long flags;
+
+	spin_lock_irqsave(&igc->tmreg_lock, flags);
+
+	igc_ptp_read_i225(igc, &now);
+	now = timespec64_add(now, then);
+	igc_ptp_write_i225(igc, (const struct timespec64 *)&now);
+
+	spin_unlock_irqrestore(&igc->tmreg_lock, flags);
+
+	return 0;
+}
+
+static int igc_ptp_gettimex64_i225(struct ptp_clock_info *ptp,
+				   struct timespec64 *ts,
+				   struct ptp_system_timestamp *sts)
+{
+	struct igc_adapter *igc = container_of(ptp, struct igc_adapter,
+					       ptp_caps);
+	struct igc_hw *hw = &igc->hw;
+	unsigned long flags;
+
+	spin_lock_irqsave(&igc->tmreg_lock, flags);
+
+	ptp_read_system_prets(sts);
+	rd32(IGC_SYSTIMR);
+	ptp_read_system_postts(sts);
+	ts->tv_nsec = rd32(IGC_SYSTIML);
+	ts->tv_sec = rd32(IGC_SYSTIMH);
+
+	spin_unlock_irqrestore(&igc->tmreg_lock, flags);
+
+	return 0;
+}
+
+static int igc_ptp_settime_i225(struct ptp_clock_info *ptp,
+				const struct timespec64 *ts)
+{
+	struct igc_adapter *igc = container_of(ptp, struct igc_adapter,
+					       ptp_caps);
+	unsigned long flags;
+
+	spin_lock_irqsave(&igc->tmreg_lock, flags);
+
+	igc_ptp_write_i225(igc, ts);
+
+	spin_unlock_irqrestore(&igc->tmreg_lock, flags);
+
+	return 0;
+}
+
+static int igc_ptp_feature_enable_i225(struct ptp_clock_info *ptp,
+				       struct ptp_clock_request *rq, int on)
+{
+	return -EOPNOTSUPP;
+}
+
+/**
+ * igc_ptp_systim_to_hwtstamp - convert system time value to HW timestamp
+ * @adapter: board private structure
+ * @hwtstamps: timestamp structure to update
+ * @systim: unsigned 64bit system time value
+ *
+ * We need to convert the system time value stored in the RX/TXSTMP registers
+ * into a hwtstamp which can be used by the upper level timestamping functions.
+ **/
+static void igc_ptp_systim_to_hwtstamp(struct igc_adapter *adapter,
+				       struct skb_shared_hwtstamps *hwtstamps,
+				       u64 systim)
+{
+	switch (adapter->hw.mac.type) {
+	case igc_i225:
+		memset(hwtstamps, 0, sizeof(*hwtstamps));
+		/* Upper 32 bits contain s, lower 32 bits contain ns. */
+		hwtstamps->hwtstamp = ktime_set(systim >> 32,
+						systim & 0xFFFFFFFF);
+		break;
+	default:
+		break;
+	}
+}
+
+/**
+ * igc_ptp_rx_pktstamp - retrieve Rx per packet timestamp
+ * @q_vector: Pointer to interrupt specific structure
+ * @va: Pointer to address containing Rx buffer
+ * @skb: Buffer containing timestamp and packet
+ *
+ * This function is meant to retrieve the first timestamp from the
+ * first buffer of an incoming frame. The value is stored in little
+ * endian format starting on byte 0. There's a second timestamp
+ * starting on byte 8.
+ **/
+void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, void *va,
+			 struct sk_buff *skb)
+{
+	struct igc_adapter *adapter = q_vector->adapter;
+	__le64 *regval = (__le64 *)va;
+	int adjust = 0;
+
+	/* The timestamp is recorded in little endian format.
+	 * DWORD: | 0          | 1           | 2          | 3
+	 * Field: | Timer0 Low | Timer0 High | Timer1 Low | Timer1 High
+	 */
+	igc_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb),
+				   le64_to_cpu(regval[0]));
+
+	/* adjust timestamp for the RX latency based on link speed */
+	if (adapter->hw.mac.type == igc_i225) {
+		switch (adapter->link_speed) {
+		case SPEED_10:
+			adjust = IGC_I225_RX_LATENCY_10;
+			break;
+		case SPEED_100:
+			adjust = IGC_I225_RX_LATENCY_100;
+			break;
+		case SPEED_1000:
+			adjust = IGC_I225_RX_LATENCY_1000;
+			break;
+		case SPEED_2500:
+			adjust = IGC_I225_RX_LATENCY_2500;
+			break;
+		}
+	}
+	skb_hwtstamps(skb)->hwtstamp =
+		ktime_sub_ns(skb_hwtstamps(skb)->hwtstamp, adjust);
+}
+
+/**
+ * igc_ptp_rx_rgtstamp - retrieve Rx timestamp stored in register
+ * @q_vector: Pointer to interrupt specific structure
+ * @skb: Buffer containing timestamp and packet
+ *
+ * This function is meant to retrieve a timestamp from the internal registers
+ * of the adapter and store it in the skb.
+ */
+void igc_ptp_rx_rgtstamp(struct igc_q_vector *q_vector,
+			 struct sk_buff *skb)
+{
+	struct igc_adapter *adapter = q_vector->adapter;
+	struct igc_hw *hw = &adapter->hw;
+	u64 regval;
+
+	/* If this bit is set, then the RX registers contain the time
+	 * stamp. No other packet will be time stamped until we read
+	 * these registers, so read the registers to make them
+	 * available again. Because only one packet can be time
+	 * stamped at a time, we know that the register values must
+	 * belong to this one here and therefore we don't need to
+	 * compare any of the additional attributes stored for it.
+	 *
+	 * If nothing went wrong, then it should have a shared
+	 * tx_flags that we can turn into a skb_shared_hwtstamps.
+	 */
+	if (!(rd32(IGC_TSYNCRXCTL) & IGC_TSYNCRXCTL_VALID))
+		return;
+
+	regval = rd32(IGC_RXSTMPL);
+	regval |= (u64)rd32(IGC_RXSTMPH) << 32;
+
+	igc_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb), regval);
+
+	/* Update the last_rx_timestamp timer in order to enable watchdog check
+	 * for error case of latched timestamp on a dropped packet.
+	 */
+	adapter->last_rx_timestamp = jiffies;
+}
+
+/**
+ * igc_ptp_enable_tstamp_rxqueue - Enable RX timestamp for a queue
+ * @rx_ring: Pointer to RX queue
+ * @timer: Index for timer
+ *
+ * This function enables RX timestamping for a queue, and selects
+ * which 1588 timer will provide the timestamp.
+ */
+static void igc_ptp_enable_tstamp_rxqueue(struct igc_adapter *adapter,
+					  struct igc_ring *rx_ring, u8 timer)
+{
+	struct igc_hw *hw = &adapter->hw;
+	int reg_idx = rx_ring->reg_idx;
+	u32 srrctl = rd32(IGC_SRRCTL(reg_idx));
+
+	srrctl |= IGC_SRRCTL_TIMESTAMP;
+	srrctl |= IGC_SRRCTL_TIMER1SEL(timer);
+	srrctl |= IGC_SRRCTL_TIMER0SEL(timer);
+
+	wr32(IGC_SRRCTL(reg_idx), srrctl);
+}
+
+static void igc_ptp_enable_tstamp_all_rxqueues(struct igc_adapter *adapter,
+					       u8 timer)
+{
+	int i;
+
+	for (i = 0; i < adapter->num_rx_queues; i++) {
+		struct igc_ring *ring = adapter->rx_ring[i];
+
+		igc_ptp_enable_tstamp_rxqueue(adapter, ring, timer);
+	}
+}
+
+/**
+ * igc_ptp_set_timestamp_mode - setup hardware for timestamping
+ * @adapter: networking device structure
+ * @config: hwtstamp configuration
+ *
+ * Outgoing time stamping can be enabled and disabled. Play nice and
+ * disable it when requested, although it shouldn't case any overhead
+ * when no packet needs it. At most one packet in the queue may be
+ * marked for time stamping, otherwise it would be impossible to tell
+ * for sure to which packet the hardware time stamp belongs.
+ *
+ * Incoming time stamping has to be configured via the hardware
+ * filters. Not all combinations are supported, in particular event
+ * type has to be specified. Matching the kind of event packet is
+ * not supported, with the exception of "all V2 events regardless of
+ * level 2 or 4".
+ *
+ */
+static int igc_ptp_set_timestamp_mode(struct igc_adapter *adapter,
+				      struct hwtstamp_config *config)
+{
+	u32 tsync_tx_ctl = IGC_TSYNCTXCTL_ENABLED;
+	u32 tsync_rx_ctl = IGC_TSYNCRXCTL_ENABLED;
+	struct igc_hw *hw = &adapter->hw;
+	u32 tsync_rx_cfg = 0;
+	bool is_l4 = false;
+	bool is_l2 = false;
+	u32 regval;
+
+	/* reserved for future extensions */
+	if (config->flags)
+		return -EINVAL;
+
+	switch (config->tx_type) {
+	case HWTSTAMP_TX_OFF:
+		tsync_tx_ctl = 0;
+	case HWTSTAMP_TX_ON:
+		break;
+	default:
+		return -ERANGE;
+	}
+
+	switch (config->rx_filter) {
+	case HWTSTAMP_FILTER_NONE:
+		tsync_rx_ctl = 0;
+		break;
+	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
+		tsync_rx_ctl |= IGC_TSYNCRXCTL_TYPE_L4_V1;
+		tsync_rx_cfg = IGC_TSYNCRXCFG_PTP_V1_SYNC_MESSAGE;
+		is_l4 = true;
+		break;
+	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
+		tsync_rx_ctl |= IGC_TSYNCRXCTL_TYPE_L4_V1;
+		tsync_rx_cfg = IGC_TSYNCRXCFG_PTP_V1_DELAY_REQ_MESSAGE;
+		is_l4 = true;
+		break;
+	case HWTSTAMP_FILTER_PTP_V2_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
+	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
+	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
+		tsync_rx_ctl |= IGC_TSYNCRXCTL_TYPE_EVENT_V2;
+		config->rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
+		is_l2 = true;
+		is_l4 = true;
+		break;
+	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
+	case HWTSTAMP_FILTER_NTP_ALL:
+	case HWTSTAMP_FILTER_ALL:
+		tsync_rx_ctl |= IGC_TSYNCRXCTL_TYPE_ALL;
+		config->rx_filter = HWTSTAMP_FILTER_ALL;
+		break;
+		/* fall through */
+	default:
+		config->rx_filter = HWTSTAMP_FILTER_NONE;
+		return -ERANGE;
+	}
+
+	/* Per-packet timestamping only works if all packets are
+	 * timestamped, so enable timestamping in all packets as long
+	 * as one Rx filter was configured.
+	 */
+	if (tsync_rx_ctl) {
+		tsync_rx_ctl = IGC_TSYNCRXCTL_ENABLED;
+		tsync_rx_ctl |= IGC_TSYNCRXCTL_TYPE_ALL;
+		tsync_rx_ctl |= IGC_TSYNCRXCTL_RXSYNSIG;
+		config->rx_filter = HWTSTAMP_FILTER_ALL;
+		is_l2 = true;
+		is_l4 = true;
+
+		if (hw->mac.type == igc_i225) {
+			regval = rd32(IGC_RXPBS);
+			regval |= IGC_RXPBS_CFG_TS_EN;
+			wr32(IGC_RXPBS, regval);
+
+			/* FIXME: For now, only support retrieving RX
+			 * timestamps from timer 0
+			 */
+			igc_ptp_enable_tstamp_all_rxqueues(adapter, 0);
+		}
+	}
+
+	if (tsync_tx_ctl) {
+		tsync_tx_ctl = IGC_TSYNCTXCTL_ENABLED;
+		tsync_tx_ctl |= IGC_TSYNCTXCTL_TXSYNSIG;
+	}
+
+	/* enable/disable TX */
+	regval = rd32(IGC_TSYNCTXCTL);
+	regval &= ~IGC_TSYNCTXCTL_ENABLED;
+	regval |= tsync_tx_ctl;
+	wr32(IGC_TSYNCTXCTL, regval);
+
+	/* enable/disable RX */
+	regval = rd32(IGC_TSYNCRXCTL);
+	regval &= ~(IGC_TSYNCRXCTL_ENABLED | IGC_TSYNCRXCTL_TYPE_MASK);
+	regval |= tsync_rx_ctl;
+	wr32(IGC_TSYNCRXCTL, regval);
+
+	/* define which PTP packets are time stamped */
+	wr32(IGC_TSYNCRXCFG, tsync_rx_cfg);
+
+	/* define ethertype filter for timestamped packets */
+	if (is_l2)
+		wr32(IGC_ETQF(3),
+		     (IGC_ETQF_FILTER_ENABLE | /* enable filter */
+		     IGC_ETQF_1588 | /* enable timestamping */
+		     ETH_P_1588)); /* 1588 eth protocol type */
+	else
+		wr32(IGC_ETQF(3), 0);
+
+	/* L4 Queue Filter[3]: filter by destination port and protocol */
+	if (is_l4) {
+		u32 ftqf = (IPPROTO_UDP /* UDP */
+			    | IGC_FTQF_VF_BP /* VF not compared */
+			    | IGC_FTQF_1588_TIME_STAMP /* Enable Timestamp */
+			    | IGC_FTQF_MASK); /* mask all inputs */
+		ftqf &= ~IGC_FTQF_MASK_PROTO_BP; /* enable protocol check */
+
+		wr32(IGC_IMIR(3), htons(PTP_EV_PORT));
+		wr32(IGC_IMIREXT(3),
+		     (IGC_IMIREXT_SIZE_BP | IGC_IMIREXT_CTRL_BP));
+		wr32(IGC_FTQF(3), ftqf);
+	} else {
+		wr32(IGC_FTQF(3), IGC_FTQF_MASK);
+	}
+	wrfl();
+
+	/* clear TX/RX time stamp registers, just to be sure */
+	regval = rd32(IGC_TXSTMPL);
+	regval = rd32(IGC_TXSTMPH);
+	regval = rd32(IGC_RXSTMPL);
+	regval = rd32(IGC_RXSTMPH);
+
+	return 0;
+}
+
+void igc_ptp_tx_hang(struct igc_adapter *adapter)
+{
+	bool timeout = time_is_before_jiffies(adapter->ptp_tx_start +
+					      IGC_PTP_TX_TIMEOUT);
+	struct igc_hw *hw = &adapter->hw;
+
+	if (!adapter->ptp_tx_skb)
+		return;
+
+	if (!test_bit(__IGC_PTP_TX_IN_PROGRESS, &adapter->state))
+		return;
+
+	/* If we haven't received a timestamp within the timeout, it is
+	 * reasonable to assume that it will never occur, so we can unlock the
+	 * timestamp bit when this occurs.
+	 */
+	if (timeout) {
+		cancel_work_sync(&adapter->ptp_tx_work);
+		dev_kfree_skb_any(adapter->ptp_tx_skb);
+		adapter->ptp_tx_skb = NULL;
+		clear_bit_unlock(__IGC_PTP_TX_IN_PROGRESS, &adapter->state);
+		adapter->tx_hwtstamp_timeouts++;
+		/* Clear the Tx valid bit in TSYNCTXCTL register to enable
+		 * interrupt
+		 */
+		rd32(IGC_TXSTMPH);
+		dev_warn(&adapter->pdev->dev, "clearing Tx timestamp hang\n");
+	}
+}
+
+/**
+ * igc_ptp_tx_hwtstamp - utility function which checks for TX time stamp
+ * @adapter: Board private structure
+ *
+ * If we were asked to do hardware stamping and such a time stamp is
+ * available, then it must have been for this skb here because we only
+ * allow only one such packet into the queue.
+ */
+static void igc_ptp_tx_hwtstamp(struct igc_adapter *adapter)
+{
+	struct sk_buff *skb = adapter->ptp_tx_skb;
+	struct skb_shared_hwtstamps shhwtstamps;
+	struct igc_hw *hw = &adapter->hw;
+	u64 regval;
+
+	regval = rd32(IGC_TXSTMPL);
+	regval |= (u64)rd32(IGC_TXSTMPH) << 32;
+	igc_ptp_systim_to_hwtstamp(adapter, &shhwtstamps, regval);
+
+	/* Clear the lock early before calling skb_tstamp_tx so that
+	 * applications are not woken up before the lock bit is clear. We use
+	 * a copy of the skb pointer to ensure other threads can't change it
+	 * while we're notifying the stack.
+	 */
+	adapter->ptp_tx_skb = NULL;
+	clear_bit_unlock(__IGC_PTP_TX_IN_PROGRESS, &adapter->state);
+
+	/* Notify the stack and free the skb after we've unlocked */
+	skb_tstamp_tx(skb, &shhwtstamps);
+	dev_kfree_skb_any(skb);
+}
+
+/**
+ * igc_ptp_tx_work
+ * @work: pointer to work struct
+ *
+ * This work function polls the TSYNCTXCTL valid bit to determine when a
+ * timestamp has been taken for the current stored skb.
+ */
+void igc_ptp_tx_work(struct work_struct *work)
+{
+	struct igc_adapter *adapter = container_of(work, struct igc_adapter,
+						   ptp_tx_work);
+	struct igc_hw *hw = &adapter->hw;
+	u32 tsynctxctl;
+
+	if (!adapter->ptp_tx_skb)
+		return;
+
+	if (time_is_before_jiffies(adapter->ptp_tx_start +
+				   IGC_PTP_TX_TIMEOUT)) {
+		dev_kfree_skb_any(adapter->ptp_tx_skb);
+		adapter->ptp_tx_skb = NULL;
+		clear_bit_unlock(__IGC_PTP_TX_IN_PROGRESS, &adapter->state);
+		adapter->tx_hwtstamp_timeouts++;
+		/* Clear the tx valid bit in TSYNCTXCTL register to enable
+		 * interrupt
+		 */
+		rd32(IGC_TXSTMPH);
+		dev_warn(&adapter->pdev->dev, "clearing Tx timestamp hang\n");
+		return;
+	}
+
+	tsynctxctl = rd32(IGC_TSYNCTXCTL);
+	if (tsynctxctl & IGC_TSYNCTXCTL_VALID)
+		igc_ptp_tx_hwtstamp(adapter);
+	else
+		/* reschedule to check later */
+		schedule_work(&adapter->ptp_tx_work);
+}
+
+/**
+ * igc_ptp_set_ts_config - set hardware time stamping config
+ * @netdev: network interface device structure
+ * @ifreq: interface request data
+ *
+ **/
+int igc_ptp_set_ts_config(struct net_device *netdev, struct ifreq *ifr)
+{
+	struct igc_adapter *adapter = netdev_priv(netdev);
+	struct hwtstamp_config config;
+	int err;
+
+	if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
+		return -EFAULT;
+
+	err = igc_ptp_set_timestamp_mode(adapter, &config);
+	if (err)
+		return err;
+
+	/* save these settings for future reference */
+	memcpy(&adapter->tstamp_config, &config,
+	       sizeof(adapter->tstamp_config));
+
+	return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
+		-EFAULT : 0;
+}
+
+/**
+ * igc_ptp_get_ts_config - get hardware time stamping config
+ * @netdev: network interface device structure
+ * @ifreq: interface request data
+ *
+ * Get the hwtstamp_config settings to return to the user. Rather than attempt
+ * to deconstruct the settings from the registers, just return a shadow copy
+ * of the last known settings.
+ **/
+int igc_ptp_get_ts_config(struct net_device *netdev, struct ifreq *ifr)
+{
+	struct igc_adapter *adapter = netdev_priv(netdev);
+	struct hwtstamp_config *config = &adapter->tstamp_config;
+
+	return copy_to_user(ifr->ifr_data, config, sizeof(*config)) ?
+		-EFAULT : 0;
+}
+
+/**
+ * igc_ptp_init - Initialize PTP functionality
+ * @adapter: Board private structure
+ *
+ * This function is called at device probe to initialize the PTP
+ * functionality.
+ */
+void igc_ptp_init(struct igc_adapter *adapter)
+{
+	struct net_device *netdev = adapter->netdev;
+	struct igc_hw *hw = &adapter->hw;
+
+	switch (hw->mac.type) {
+	case igc_i225:
+		snprintf(adapter->ptp_caps.name, 16, "%pm", netdev->dev_addr);
+		adapter->ptp_caps.owner = THIS_MODULE;
+		adapter->ptp_caps.max_adj = 62499999;
+		adapter->ptp_caps.adjfine = igc_ptp_adjfine_i225;
+		adapter->ptp_caps.adjtime = igc_ptp_adjtime_i225;
+		adapter->ptp_caps.gettimex64 = igc_ptp_gettimex64_i225;
+		adapter->ptp_caps.settime64 = igc_ptp_settime_i225;
+		adapter->ptp_caps.enable = igc_ptp_feature_enable_i225;
+		break;
+	default:
+		adapter->ptp_clock = NULL;
+		return;
+	}
+
+	spin_lock_init(&adapter->tmreg_lock);
+	INIT_WORK(&adapter->ptp_tx_work, igc_ptp_tx_work);
+
+	adapter->tstamp_config.rx_filter = HWTSTAMP_FILTER_NONE;
+	adapter->tstamp_config.tx_type = HWTSTAMP_TX_OFF;
+
+	igc_ptp_reset(adapter);
+
+	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_caps,
+						&adapter->pdev->dev);
+	if (IS_ERR(adapter->ptp_clock)) {
+		adapter->ptp_clock = NULL;
+		dev_err(&adapter->pdev->dev, "ptp_clock_register failed\n");
+	} else if (adapter->ptp_clock) {
+		dev_info(&adapter->pdev->dev, "added PHC on %s\n",
+			 adapter->netdev->name);
+		adapter->ptp_flags |= IGC_PTP_ENABLED;
+	}
+}
+
+/**
+ * igc_ptp_suspend - Disable PTP work items and prepare for suspend
+ * @adapter: Board private structure
+ *
+ * This function stops the overflow check work and PTP Tx timestamp work, and
+ * will prepare the device for OS suspend.
+ */
+void igc_ptp_suspend(struct igc_adapter *adapter)
+{
+	if (!(adapter->ptp_flags & IGC_PTP_ENABLED))
+		return;
+
+	cancel_work_sync(&adapter->ptp_tx_work);
+	if (adapter->ptp_tx_skb) {
+		dev_kfree_skb_any(adapter->ptp_tx_skb);
+		adapter->ptp_tx_skb = NULL;
+		clear_bit_unlock(__IGC_PTP_TX_IN_PROGRESS, &adapter->state);
+	}
+}
+
+/**
+ * igc_ptp_stop - Disable PTP device and stop the overflow check.
+ * @adapter: Board private structure.
+ *
+ * This function stops the PTP support and cancels the delayed work.
+ **/
+void igc_ptp_stop(struct igc_adapter *adapter)
+{
+	igc_ptp_suspend(adapter);
+
+	if (adapter->ptp_clock) {
+		ptp_clock_unregister(adapter->ptp_clock);
+		dev_info(&adapter->pdev->dev, "removed PHC on %s\n",
+			 adapter->netdev->name);
+		adapter->ptp_flags &= ~IGC_PTP_ENABLED;
+	}
+}
+
+/**
+ * igc_ptp_reset - Re-enable the adapter for PTP following a reset.
+ * @adapter: Board private structure.
+ *
+ * This function handles the reset work required to re-enable the PTP device.
+ **/
+void igc_ptp_reset(struct igc_adapter *adapter)
+{
+	struct igc_hw *hw = &adapter->hw;
+	unsigned long flags;
+
+	/* reset the tstamp_config */
+	igc_ptp_set_timestamp_mode(adapter, &adapter->tstamp_config);
+
+	spin_lock_irqsave(&adapter->tmreg_lock, flags);
+
+	switch (adapter->hw.mac.type) {
+	case igc_i225:
+		wr32(IGC_TSAUXC, 0x0);
+		wr32(IGC_TSSDP, 0x0);
+		wr32(IGC_TSIM, IGC_TSICR_INTERRUPTS);
+		wr32(IGC_IMS, IGC_IMS_TS);
+		break;
+	default:
+		/* No work to do. */
+		goto out;
+	}
+
+	/* Re-initialize the timer. */
+	if (hw->mac.type == igc_i225) {
+		struct timespec64 ts64 = ktime_to_timespec64(ktime_get_real());
+
+		igc_ptp_write_i225(adapter, &ts64);
+	} else {
+		timecounter_init(&adapter->tc, &adapter->cc,
+				 ktime_to_ns(ktime_get_real()));
+	}
+out:
+	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
+
+	wrfl();
+}

drivers/net/ethernet/intel/igc/igc_regs.h

@@ -209,6 +209,33 @@
 #define IGC_LENERRS	0x04138  /* Length Errors Count */
 #define IGC_HRMPC	0x0A018  /* Header Redirection Missed Packet Count */
 
+/* Time sync registers */
+#define IGC_TSICR	0x0B66C  /* Time Sync Interrupt Cause */
+#define IGC_TSIM	0x0B674  /* Time Sync Interrupt Mask Register */
+#define IGC_TSAUXC	0x0B640  /* Timesync Auxiliary Control register */
+#define IGC_TSYNCRXCTL	0x0B620  /* Rx Time Sync Control register - RW */
+#define IGC_TSYNCTXCTL	0x0B614  /* Tx Time Sync Control register - RW */
+#define IGC_TSYNCRXCFG	0x05F50  /* Time Sync Rx Configuration - RW */
+#define IGC_TSSDP	0x0003C  /* Time Sync SDP Configuration Register - RW */
+
+#define IGC_IMIR(_i)	(0x05A80 + ((_i) * 4))  /* Immediate Interrupt */
+#define IGC_IMIREXT(_i)	(0x05AA0 + ((_i) * 4))  /* Immediate INTR Ext*/
+
+#define IGC_FTQF(_n)	(0x059E0 + (4 * (_n)))  /* 5-tuple Queue Fltr */
+
+#define IGC_RXPBS	0x02404  /* Rx Packet Buffer Size - RW */
+
+/* System Time Registers */
+#define IGC_SYSTIML	0x0B600  /* System time register Low - RO */
+#define IGC_SYSTIMH	0x0B604  /* System time register High - RO */
+#define IGC_SYSTIMR	0x0B6F8  /* System time register Residue */
+#define IGC_TIMINCA	0x0B608  /* Increment attributes register - RW */
+
+#define IGC_RXSTMPL	0x0B624  /* Rx timestamp Low - RO */
+#define IGC_RXSTMPH	0x0B628  /* Rx timestamp High - RO */
+#define IGC_TXSTMPL	0x0B618  /* Tx timestamp value Low - RO */
+#define IGC_TXSTMPH	0x0B61C  /* Tx timestamp value High - RO */
+
 /* Management registers */
 #define IGC_MANC	0x05820  /* Management Control - RW */