ptp_qoriq: support external trigger stamp FIFO

The external trigger stamp FIFO was introduced as a new feature
for QorIQ 1588 timer IP block. This patch is to support it by
adding a new dts property "fsl,extts-fifo". Any QorIQ 1588 timer
supporting this feature is required to add this property in its
dts node.

In addition, the FIFO should be cleaned up before enabling external
trigger interrupts. Otherwise, there will be interrupts immediately
just after enabling external trigger interrupts.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 54 insertions, 14 deletions

diff --git a/drivers/ptp/ptp_qoriq.c b/drivers/ptp/ptp_qoriq.c
index 274321471d50..a2e7702db3a4 100644
--- a/drivers/ptp/ptp_qoriq.c
+++ b/drivers/ptp/ptp_qoriq.c
@@ -88,6 +88,49 @@ static void set_fipers(struct qoriq_ptp *qoriq_ptp)
 	qoriq_write(&regs->fiper_regs->tmr_fiper2, qoriq_ptp->tmr_fiper2);
 }
 
+static int extts_clean_up(struct qoriq_ptp *qoriq_ptp, int index,
+			  bool update_event)
+{
+	struct qoriq_ptp_registers *regs = &qoriq_ptp->regs;
+	struct ptp_clock_event event;
+	void __iomem *reg_etts_l;
+	void __iomem *reg_etts_h;
+	u32 valid, stat, lo, hi;
+
+	switch (index) {
+	case 0:
+		valid = ETS1_VLD;
+		reg_etts_l = &regs->etts_regs->tmr_etts1_l;
+		reg_etts_h = &regs->etts_regs->tmr_etts1_h;
+		break;
+	case 1:
+		valid = ETS2_VLD;
+		reg_etts_l = &regs->etts_regs->tmr_etts2_l;
+		reg_etts_h = &regs->etts_regs->tmr_etts2_h;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	event.type = PTP_CLOCK_EXTTS;
+	event.index = index;
+
+	do {
+		lo = qoriq_read(reg_etts_l);
+		hi = qoriq_read(reg_etts_h);
+
+		if (update_event) {
+			event.timestamp = ((u64) hi) << 32;
+			event.timestamp |= lo;
+			ptp_clock_event(qoriq_ptp->clock, &event);
+		}
+
+		stat = qoriq_read(&regs->ctrl_regs->tmr_stat);
+	} while (qoriq_ptp->extts_fifo_support && (stat & valid));
+
+	return 0;
+}
+
 /*
  * Interrupt service routine
  */
@@ -111,24 +154,12 @@ static irqreturn_t isr(int irq, void *priv)
 
 	if (irqs & ETS1) {
 		ack |= ETS1;
-		hi = qoriq_read(&regs->etts_regs->tmr_etts1_h);
-		lo = qoriq_read(&regs->etts_regs->tmr_etts1_l);
-		event.type = PTP_CLOCK_EXTTS;
-		event.index = 0;
-		event.timestamp = ((u64) hi) << 32;
-		event.timestamp |= lo;
-		ptp_clock_event(qoriq_ptp->clock, &event);
+		extts_clean_up(qoriq_ptp, 0, true);
 	}
 
 	if (irqs & ETS2) {
 		ack |= ETS2;
-		hi = qoriq_read(&regs->etts_regs->tmr_etts2_h);
-		lo = qoriq_read(&regs->etts_regs->tmr_etts2_l);
-		event.type = PTP_CLOCK_EXTTS;
-		event.index = 1;
-		event.timestamp = ((u64) hi) << 32;
-		event.timestamp |= lo;
-		ptp_clock_event(qoriq_ptp->clock, &event);
+		extts_clean_up(qoriq_ptp, 1, true);
 	}
 
 	if (irqs & ALM2) {
@@ -278,6 +309,10 @@ static int ptp_qoriq_enable(struct ptp_clock_info *ptp,
 		default:
 			return -EINVAL;
 		}
+
+		if (on)
+			extts_clean_up(qoriq_ptp, rq->extts.index, false);
+
 		break;
 	case PTP_CLK_REQ_PPS:
 		bit = PP1EN;
@@ -441,6 +476,11 @@ static int qoriq_ptp_probe(struct platform_device *dev)
 	if (of_property_read_u32(node, "fsl,cksel", &qoriq_ptp->cksel))
 		qoriq_ptp->cksel = DEFAULT_CKSEL;
 
+	if (of_property_read_bool(node, "fsl,extts-fifo"))
+		qoriq_ptp->extts_fifo_support = true;
+	else
+		qoriq_ptp->extts_fifo_support = false;
+
 	if (of_property_read_u32(node,
 				 "fsl,tclk-period", &qoriq_ptp->tclk_period) ||
 	    of_property_read_u32(node,