net: mscc: ocelot: add support for PTP waveform configuration

For PPS output (perout period is 1.000000000), accept the new "phase"
parameter from the periodic output request structure.

For both PPS and freeform output, accept the new "on" argument for
specifying the duty cycle of the generated signal. Preserve the old
defaults for this "on" time: 1 us for PPS, and half the period for
freeform output.

Also preserve the old behavior that accepted the "phase" via the "start"
argument.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mscc/ocelot_ptp.c

@@ -184,18 +184,20 @@ int ocelot_ptp_enable(struct ptp_clock_info *ptp,
 		      struct ptp_clock_request *rq, int on)
 {
 	struct ocelot *ocelot = container_of(ptp, struct ocelot, ptp_info);
-	struct timespec64 ts_start, ts_period;
+	struct timespec64 ts_phase, ts_period;
 	enum ocelot_ptp_pins ptp_pin;
 	unsigned long flags;
 	bool pps = false;
 	int pin = -1;
+	s64 wf_high;
+	s64 wf_low;
 	u32 val;
-	s64 ns;
 
 	switch (rq->type) {
 	case PTP_CLK_REQ_PEROUT:
 		/* Reject requests with unsupported flags */
-		if (rq->perout.flags)
+		if (rq->perout.flags & ~(PTP_PEROUT_DUTY_CYCLE |
+					 PTP_PEROUT_PHASE))
 			return -EOPNOTSUPP;
 
 		pin = ptp_find_pin(ocelot->ptp_clock, PTP_PF_PEROUT,
@@ -211,22 +213,12 @@ int ocelot_ptp_enable(struct ptp_clock_info *ptp,
 		else
 			return -EBUSY;
 
-		ts_start.tv_sec = rq->perout.start.sec;
-		ts_start.tv_nsec = rq->perout.start.nsec;
 		ts_period.tv_sec = rq->perout.period.sec;
 		ts_period.tv_nsec = rq->perout.period.nsec;
 
 		if (ts_period.tv_sec == 1 && ts_period.tv_nsec == 0)
 			pps = true;
 
-		if (ts_start.tv_sec || (ts_start.tv_nsec && !pps)) {
-			dev_warn(ocelot->dev,
-				 "Absolute start time not supported!\n");
-			dev_warn(ocelot->dev,
-				 "Accept nsec for PPS phase adjustment, otherwise start time should be 0 0.\n");
-			return -EINVAL;
-		}
-
 		/* Handle turning off */
 		if (!on) {
 			spin_lock_irqsave(&ocelot->ptp_clock_lock, flags);
@@ -236,16 +228,48 @@ int ocelot_ptp_enable(struct ptp_clock_info *ptp,
 			break;
 		}
 
+		if (rq->perout.flags & PTP_PEROUT_PHASE) {
+			ts_phase.tv_sec = rq->perout.phase.sec;
+			ts_phase.tv_nsec = rq->perout.phase.nsec;
+		} else {
+			/* Compatibility */
+			ts_phase.tv_sec = rq->perout.start.sec;
+			ts_phase.tv_nsec = rq->perout.start.nsec;
+		}
+		if (ts_phase.tv_sec || (ts_phase.tv_nsec && !pps)) {
+			dev_warn(ocelot->dev,
+				 "Absolute start time not supported!\n");
+			dev_warn(ocelot->dev,
+				 "Accept nsec for PPS phase adjustment, otherwise start time should be 0 0.\n");
+			return -EINVAL;
+		}
+
+		/* Calculate waveform high and low times */
+		if (rq->perout.flags & PTP_PEROUT_DUTY_CYCLE) {
+			struct timespec64 ts_on;
+
+			ts_on.tv_sec = rq->perout.on.sec;
+			ts_on.tv_nsec = rq->perout.on.nsec;
+
+			wf_high = timespec64_to_ns(&ts_on);
+		} else {
+			if (pps) {
+				wf_high = 1000;
+			} else {
+				wf_high = timespec64_to_ns(&ts_period);
+				wf_high = div_s64(wf_high, 2);
+			}
+		}
+
+		wf_low = timespec64_to_ns(&ts_period);
+		wf_low -= wf_high;
+
 		/* Handle PPS request */
 		if (pps) {
 			spin_lock_irqsave(&ocelot->ptp_clock_lock, flags);
-			/* Pulse generated perout.start.nsec after TOD has
-			 * increased seconds.
-			 * Pulse width is set to 1us.
-			 */
-			ocelot_write_rix(ocelot, ts_start.tv_nsec,
+			ocelot_write_rix(ocelot, ts_phase.tv_nsec,
 					 PTP_PIN_WF_LOW_PERIOD, ptp_pin);
-			ocelot_write_rix(ocelot, 1000,
+			ocelot_write_rix(ocelot, wf_high,
 					 PTP_PIN_WF_HIGH_PERIOD, ptp_pin);
 			val = PTP_PIN_CFG_ACTION(PTP_PIN_ACTION_CLOCK);
 			val |= PTP_PIN_CFG_SYNC;
@@ -255,14 +279,16 @@ int ocelot_ptp_enable(struct ptp_clock_info *ptp,
 		}
 
 		/* Handle periodic clock */
-		ns = timespec64_to_ns(&ts_period);
-		ns = ns >> 1;
-		if (ns > 0x3fffffff || ns <= 0x6)
+		if (wf_high > 0x3fffffff || wf_high <= 0x6)
+			return -EINVAL;
+		if (wf_low > 0x3fffffff || wf_low <= 0x6)
 			return -EINVAL;
 
 		spin_lock_irqsave(&ocelot->ptp_clock_lock, flags);
-		ocelot_write_rix(ocelot, ns, PTP_PIN_WF_LOW_PERIOD, ptp_pin);
-		ocelot_write_rix(ocelot, ns, PTP_PIN_WF_HIGH_PERIOD, ptp_pin);
+		ocelot_write_rix(ocelot, wf_low, PTP_PIN_WF_LOW_PERIOD,
+				 ptp_pin);
+		ocelot_write_rix(ocelot, wf_high, PTP_PIN_WF_HIGH_PERIOD,
+				 ptp_pin);
 		val = PTP_PIN_CFG_ACTION(PTP_PIN_ACTION_CLOCK);
 		ocelot_write_rix(ocelot, val, PTP_PIN_CFG, ptp_pin);
 		spin_unlock_irqrestore(&ocelot->ptp_clock_lock, flags);