Subject: [PATCH 37/45] net/mlx5e: Change 1PPS out scheme

From: Eugenia Emantayev <[email-masked]>
Date: Sun, 28 May 2017 14:06:01 +0300

[ Upstream commit 4272f9b88db9223216cdf87314f570f6d81295b4 ]

In order to fix the drift in 1PPS out need to adjust the next pulse.
On each 1PPS out falling edge driver gets the event, then the event
handler adjusts the next pulse starting time.

Fixes: ee7f12205abc ('net/mlx5e: Implement 1PPS support')
Signed-off-by: Eugenia Emantayev <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 drivers/net/ethernet/mellanox/mlx5/core/en.h       |   9 +-
 drivers/net/ethernet/mellanox/mlx5/core/en_clock.c | 116 ++++++++++++++-------
 2 files changed, 87 insertions(+), 38 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index 944fc1742464..08c303c0be10 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -261,6 +261,13 @@ struct mlx5e_dcbx {
 };
 #endif
 
+#define MAX_PIN_NUM	8
+struct mlx5e_pps {
+	u8                         pin_caps[MAX_PIN_NUM];
+	struct work_struct         out_work;
+	u64                        start[MAX_PIN_NUM];
+};
+
 struct mlx5e_tstamp {
 	rwlock_t                   lock;
 	struct cyclecounter        cycles;
@@ -272,7 +279,7 @@ struct mlx5e_tstamp {
 	struct mlx5_core_dev      *mdev;
 	struct ptp_clock          *ptp;
 	struct ptp_clock_info      ptp_info;
-	u8                        *pps_pin_caps;
+	struct mlx5e_pps           pps_info;
 };
 
 enum {
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_clock.c b/drivers/net/ethernet/mellanox/mlx5/core/en_clock.c
index 41397de86f89..da9fa20f93d5 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_clock.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_clock.c
@@ -82,6 +82,33 @@ static u64 mlx5e_read_internal_timer(const struct cyclecounter *cc)
 	return mlx5_read_internal_timer(tstamp->mdev) & cc->mask;
 }
 
+static void mlx5e_pps_out(struct work_struct *work)
+{
+	struct mlx5e_pps *pps_info = container_of(work, struct mlx5e_pps,
+						  out_work);
+	struct mlx5e_tstamp *tstamp = container_of(pps_info, struct mlx5e_tstamp,
+						   pps_info);
+	u32 in[MLX5_ST_SZ_DW(mtpps_reg)] = {0};
+	unsigned long flags;
+	int i;
+
+	for (i = 0; i < tstamp->ptp_info.n_pins; i++) {
+		u64 tstart;
+
+		write_lock_irqsave(&tstamp->lock, flags);
+		tstart = tstamp->pps_info.start[i];
+		tstamp->pps_info.start[i] = 0;
+		write_unlock_irqrestore(&tstamp->lock, flags);
+		if (!tstart)
+			continue;
+
+		MLX5_SET(mtpps_reg, in, pin, i);
+		MLX5_SET64(mtpps_reg, in, time_stamp, tstart);
+		MLX5_SET(mtpps_reg, in, field_select, MLX5E_MTPPS_FS_TIME_STAMP);
+		mlx5_set_mtpps(tstamp->mdev, in, sizeof(in));
+	}
+}
+
 static void mlx5e_timestamp_overflow(struct work_struct *work)
 {
 	struct delayed_work *dwork = to_delayed_work(work);
@@ -223,21 +250,6 @@ static int mlx5e_ptp_adjfreq(struct ptp_clock_info *ptp, s32 delta)
 	int neg_adj = 0;
 	struct mlx5e_tstamp *tstamp = container_of(ptp, struct mlx5e_tstamp,
 						  ptp_info);
-	struct mlx5e_priv *priv =
-		container_of(tstamp, struct mlx5e_priv, tstamp);
-
-	if (MLX5_CAP_GEN(priv->mdev, pps_modify)) {
-		u32 in[MLX5_ST_SZ_DW(mtpps_reg)] = {0};
-
-		/* For future use need to add a loop for finding all 1PPS out pins */
-		MLX5_SET(mtpps_reg, in, pin_mode, MLX5E_PIN_MODE_OUT);
-		MLX5_SET(mtpps_reg, in, enhanced_out_periodic_adjustment, delta);
-		MLX5_SET(mtpps_reg, in, field_select,
-			 MLX5E_MTPPS_FS_PIN_MODE |
-			 MLX5E_MTPPS_FS_ENH_OUT_PER_ADJ);
-
-		mlx5_set_mtpps(priv->mdev, in, sizeof(in));
-	}
 
 	if (delta < 0) {
 		neg_adj = 1;
@@ -315,7 +327,7 @@ static int mlx5e_perout_configure(struct ptp_clock_info *ptp,
 	struct mlx5e_priv *priv =
 		container_of(tstamp, struct mlx5e_priv, tstamp);
 	u32 in[MLX5_ST_SZ_DW(mtpps_reg)] = {0};
-	u64 nsec_now, nsec_delta, time_stamp;
+	u64 nsec_now, nsec_delta, time_stamp = 0;
 	u64 cycles_now, cycles_delta;
 	struct timespec64 ts;
 	unsigned long flags;
@@ -323,6 +335,7 @@ static int mlx5e_perout_configure(struct ptp_clock_info *ptp,
 	u8 pin_mode = 0;
 	u8 pattern = 0;
 	int pin = -1;
+	int err = 0;
 	s64 ns;
 
 	if (!MLX5_PPS_CAP(priv->mdev))
@@ -373,7 +386,12 @@ static int mlx5e_perout_configure(struct ptp_clock_info *ptp,
 	MLX5_SET64(mtpps_reg, in, time_stamp, time_stamp);
 	MLX5_SET(mtpps_reg, in, field_select, field_select);
 
-	return mlx5_set_mtpps(priv->mdev, in, sizeof(in));
+	err = mlx5_set_mtpps(priv->mdev, in, sizeof(in));
+	if (err)
+		return err;
+
+	return mlx5_set_mtppse(priv->mdev, pin, 0,
+			       MLX5E_EVENT_MODE_REPETETIVE & on);
 }
 
 static int mlx5e_ptp_enable(struct ptp_clock_info *ptp,
@@ -457,22 +475,50 @@ static void mlx5e_get_pps_caps(struct mlx5e_priv *priv,
 	tstamp->ptp_info.n_per_out = MLX5_GET(mtpps_reg, out,
 					      cap_max_num_of_pps_out_pins);
 
-	tstamp->pps_pin_caps[0] = MLX5_GET(mtpps_reg, out, cap_pin_0_mode);
-	tstamp->pps_pin_caps[1] = MLX5_GET(mtpps_reg, out, cap_pin_1_mode);
-	tstamp->pps_pin_caps[2] = MLX5_GET(mtpps_reg, out, cap_pin_2_mode);
-	tstamp->pps_pin_caps[3] = MLX5_GET(mtpps_reg, out, cap_pin_3_mode);
-	tstamp->pps_pin_caps[4] = MLX5_GET(mtpps_reg, out, cap_pin_4_mode);
-	tstamp->pps_pin_caps[5] = MLX5_GET(mtpps_reg, out, cap_pin_5_mode);
-	tstamp->pps_pin_caps[6] = MLX5_GET(mtpps_reg, out, cap_pin_6_mode);
-	tstamp->pps_pin_caps[7] = MLX5_GET(mtpps_reg, out, cap_pin_7_mode);
+	tstamp->pps_info.pin_caps[0] = MLX5_GET(mtpps_reg, out, cap_pin_0_mode);
+	tstamp->pps_info.pin_caps[1] = MLX5_GET(mtpps_reg, out, cap_pin_1_mode);
+	tstamp->pps_info.pin_caps[2] = MLX5_GET(mtpps_reg, out, cap_pin_2_mode);
+	tstamp->pps_info.pin_caps[3] = MLX5_GET(mtpps_reg, out, cap_pin_3_mode);
+	tstamp->pps_info.pin_caps[4] = MLX5_GET(mtpps_reg, out, cap_pin_4_mode);
+	tstamp->pps_info.pin_caps[5] = MLX5_GET(mtpps_reg, out, cap_pin_5_mode);
+	tstamp->pps_info.pin_caps[6] = MLX5_GET(mtpps_reg, out, cap_pin_6_mode);
+	tstamp->pps_info.pin_caps[7] = MLX5_GET(mtpps_reg, out, cap_pin_7_mode);
 }
 
 void mlx5e_pps_event_handler(struct mlx5e_priv *priv,
 			     struct ptp_clock_event *event)
 {
+	struct net_device *netdev = priv->netdev;
 	struct mlx5e_tstamp *tstamp = &priv->tstamp;
+	struct timespec64 ts;
+	u64 nsec_now, nsec_delta;
+	u64 cycles_now, cycles_delta;
+	int pin = event->index;
+	s64 ns;
+	unsigned long flags;
 
-	ptp_clock_event(tstamp->ptp, event);
+	switch (tstamp->ptp_info.pin_config[pin].func) {
+	case PTP_PF_EXTTS:
+		ptp_clock_event(tstamp->ptp, event);
+		break;
+	case PTP_PF_PEROUT:
+		mlx5e_ptp_gettime(&tstamp->ptp_info, &ts);
+		cycles_now = mlx5_read_internal_timer(tstamp->mdev);
+		ts.tv_sec += 1;
+		ts.tv_nsec = 0;
+		ns = timespec64_to_ns(&ts);
+		write_lock_irqsave(&tstamp->lock, flags);
+		nsec_now = timecounter_cyc2time(&tstamp->clock, cycles_now);
+		nsec_delta = ns - nsec_now;
+		cycles_delta = div64_u64(nsec_delta << tstamp->cycles.shift,
+					 tstamp->cycles.mult);
+		tstamp->pps_info.start[pin] = cycles_now + cycles_delta;
+		queue_work(priv->wq, &tstamp->pps_info.out_work);
+		write_unlock_irqrestore(&tstamp->lock, flags);
+		break;
+	default:
+		netdev_err(netdev, "%s: Unhandled event\n", __func__);
+	}
 }
 
 void mlx5e_timestamp_init(struct mlx5e_priv *priv)
@@ -508,6 +554,7 @@ void mlx5e_timestamp_init(struct mlx5e_priv *priv)
 	do_div(ns, NSEC_PER_SEC / 2 / HZ);
 	tstamp->overflow_period = ns;
 
+	INIT_WORK(&tstamp->pps_info.out_work, mlx5e_pps_out);
 	INIT_DELAYED_WORK(&tstamp->overflow_work, mlx5e_timestamp_overflow);
 	if (tstamp->overflow_period)
 		schedule_delayed_work(&tstamp->overflow_work, 0);
@@ -519,16 +566,10 @@ void mlx5e_timestamp_init(struct mlx5e_priv *priv)
 	snprintf(tstamp->ptp_info.name, 16, "mlx5 ptp");
 
 	/* Initialize 1PPS data structures */
-#define MAX_PIN_NUM	8
-	tstamp->pps_pin_caps = kzalloc(sizeof(u8) * MAX_PIN_NUM, GFP_KERNEL);
-	if (tstamp->pps_pin_caps) {
-		if (MLX5_PPS_CAP(priv->mdev))
-			mlx5e_get_pps_caps(priv, tstamp);
-		if (tstamp->ptp_info.n_pins)
-			mlx5e_init_pin_config(tstamp);
-	} else {
-		mlx5_core_warn(priv->mdev, "1PPS initialization failed\n");
-	}
+	if (MLX5_PPS_CAP(priv->mdev))
+		mlx5e_get_pps_caps(priv, tstamp);
+	if (tstamp->ptp_info.n_pins)
+		mlx5e_init_pin_config(tstamp);
 
 	tstamp->ptp = ptp_clock_register(&tstamp->ptp_info,
 					 &priv->mdev->pdev->dev);
@@ -551,7 +592,8 @@ void mlx5e_timestamp_cleanup(struct mlx5e_priv *priv)
 		priv->tstamp.ptp = NULL;
 	}
 
-	kfree(tstamp->pps_pin_caps);
+	cancel_work_sync(&tstamp->pps_info.out_work);
+
 	kfree(tstamp->ptp_info.pin_config);
 
 	cancel_delayed_work_sync(&tstamp->overflow_work);
-- 
2.13.4