igb: enable internal PPS for the i210

The i210 device can produce an interrupt on the full second. This
patch allows using this interrupt to generate an internal PPS event
for adjusting the kernel system time.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/igb/igb_main.c

@@ -5387,14 +5387,26 @@ void igb_update_stats(struct igb_adapter *adapter,
 static void igb_tsync_interrupt(struct igb_adapter *adapter)
 {
 	struct e1000_hw *hw = &adapter->hw;
-	u32 tsicr = rd32(E1000_TSICR);
+	struct ptp_clock_event event;
+	u32 ack = 0, tsicr = rd32(E1000_TSICR);
+
+	if (tsicr & TSINTR_SYS_WRAP) {
+		event.type = PTP_CLOCK_PPS;
+		if (adapter->ptp_caps.pps)
+			ptp_clock_event(adapter->ptp_clock, &event);
+		else
+			dev_err(&adapter->pdev->dev, "unexpected SYS WRAP");
+		ack |= TSINTR_SYS_WRAP;
+	}
 
 	if (tsicr & E1000_TSICR_TXTS) {
-		/* acknowledge the interrupt */
-		wr32(E1000_TSICR, E1000_TSICR_TXTS);
 		/* retrieve hardware timestamp */
 		schedule_work(&adapter->ptp_tx_work);
+		ack |= E1000_TSICR_TXTS;
 	}
+
+	/* acknowledge the interrupts */
+	wr32(E1000_TSICR, ack);
 }
 
 static irqreturn_t igb_msix_other(int irq, void *data)

drivers/net/ethernet/intel/igb/igb_ptp.c

@@ -355,6 +355,34 @@ static int igb_ptp_settime_i210(struct ptp_clock_info *ptp,
 	return 0;
 }
 
+static int igb_ptp_feature_enable_i210(struct ptp_clock_info *ptp,
+				       struct ptp_clock_request *rq, int on)
+{
+	struct igb_adapter *igb =
+		container_of(ptp, struct igb_adapter, ptp_caps);
+	struct e1000_hw *hw = &igb->hw;
+	unsigned long flags;
+	u32 tsim;
+
+	switch (rq->type) {
+	case PTP_CLK_REQ_PPS:
+		spin_lock_irqsave(&igb->tmreg_lock, flags);
+		tsim = rd32(E1000_TSIM);
+		if (on)
+			tsim |= TSINTR_SYS_WRAP;
+		else
+			tsim &= ~TSINTR_SYS_WRAP;
+		wr32(E1000_TSIM, tsim);
+		spin_unlock_irqrestore(&igb->tmreg_lock, flags);
+		return 0;
+
+	default:
+		break;
+	}
+
+	return -EOPNOTSUPP;
+}
+
 static int igb_ptp_feature_enable(struct ptp_clock_info *ptp,
 				  struct ptp_clock_request *rq, int on)
 {
@@ -797,12 +825,12 @@ void igb_ptp_init(struct igb_adapter *adapter)
 		adapter->ptp_caps.owner = THIS_MODULE;
 		adapter->ptp_caps.max_adj = 62499999;
 		adapter->ptp_caps.n_ext_ts = 0;
-		adapter->ptp_caps.pps = 0;
+		adapter->ptp_caps.pps = 1;
 		adapter->ptp_caps.adjfreq = igb_ptp_adjfreq_82580;
 		adapter->ptp_caps.adjtime = igb_ptp_adjtime_i210;
 		adapter->ptp_caps.gettime = igb_ptp_gettime_i210;
 		adapter->ptp_caps.settime = igb_ptp_settime_i210;
-		adapter->ptp_caps.enable = igb_ptp_feature_enable;
+		adapter->ptp_caps.enable = igb_ptp_feature_enable_i210;
 		/* Enable the timer functions by clearing bit 31. */
 		wr32(E1000_TSAUXC, 0x0);
 		break;