[PATCH 1/5] ptp: ocp: Add ptp_ocp_adjtime_coarse for large adjustments

Subsystems: networking drivers, opencompute ptp clock driver, ptp hardware clock support, the rest

STALE1763d

6 messages, 2 authors, 2021-12-18 · open the first message on its own page

[PATCH 1/5] ptp: ocp: Add ptp_ocp_adjtime_coarse for large adjustments

From: Jonathan Lemon <hidden>
Date: 2021-12-16 20:07:47

In ("ptp: ocp: Have FPGA fold in ns adjustment for adjtime."), the
ns adjustment was written to the FPGA register, so the clock could
accurately perform adjustments.

However, the adjtime() call passes in a s64, while the clock adjustment
registers use a s32.  When trying to perform adjustments with a large
value (37 sec), things fail.

Examine the incoming delta, and if larger than 1 sec, use the original
(coarse) adjustment method.  If smaller than 1 sec, then allow the
FPGA to fold in the changes over a 1 second window.

Fixes: 2d97ed56f671 ("ptp: ocp: Have FPGA fold in ns adjustment for adjtime.")
Signed-off-by: Jonathan Lemon <redacted>
---
 drivers/ptp/ptp_ocp.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
index 0f1b5a7d2a89..17ad5f0d13b2 100644
--- a/drivers/ptp/ptp_ocp.c
+++ b/drivers/ptp/ptp_ocp.c

@@ -607,7 +607,7 @@ ptp_ocp_settime(struct ptp_clock_info *ptp_info, const struct timespec64 *ts)
 }
 
 static void
-__ptp_ocp_adjtime_locked(struct ptp_ocp *bp, u64 adj_val)
+__ptp_ocp_adjtime_locked(struct ptp_ocp *bp, u32 adj_val)
 {
 	u32 select, ctrl;

@@ -615,7 +615,7 @@ __ptp_ocp_adjtime_locked(struct ptp_ocp *bp, u64 adj_val)
 	iowrite32(OCP_SELECT_CLK_REG, &bp->reg->select);
 
 	iowrite32(adj_val, &bp->reg->offset_ns);
-	iowrite32(adj_val & 0x7f, &bp->reg->offset_window_ns);
+	iowrite32(NSEC_PER_SEC, &bp->reg->offset_window_ns);
 
 	ctrl = OCP_CTRL_ADJUST_OFFSET | OCP_CTRL_ENABLE;
 	iowrite32(ctrl, &bp->reg->ctrl);

@@ -624,6 +624,22 @@ __ptp_ocp_adjtime_locked(struct ptp_ocp *bp, u64 adj_val)
 	iowrite32(select >> 16, &bp->reg->select);
 }
 
+static void
+ptp_ocp_adjtime_coarse(struct ptp_ocp *bp, u64 delta_ns)
+{
+	struct timespec64 ts;
+	unsigned long flags;
+	int err;
+
+	spin_lock_irqsave(&bp->lock, flags);
+	err = __ptp_ocp_gettime_locked(bp, &ts, NULL);
+	if (likely(!err)) {
+		timespec64_add_ns(&ts, delta_ns);
+		__ptp_ocp_settime_locked(bp, &ts);
+	}
+	spin_unlock_irqrestore(&bp->lock, flags);
+}
+
 static int
 ptp_ocp_adjtime(struct ptp_clock_info *ptp_info, s64 delta_ns)
 {

@@ -631,6 +647,11 @@ ptp_ocp_adjtime(struct ptp_clock_info *ptp_info, s64 delta_ns)
 	unsigned long flags;
 	u32 adj_ns, sign;
 
+	if (delta_ns > NSEC_PER_SEC || -delta_ns > NSEC_PER_SEC) {
+		ptp_ocp_adjtime_coarse(bp, delta_ns);
+		return 0;
+	}
+
 	sign = delta_ns < 0 ? BIT(31) : 0;
 	adj_ns = sign ? -delta_ns : delta_ns;

-- 
2.31.1

[PATCH 2/5] ptp: ocp: Expose clock status drift and offset

From: Jonathan Lemon <hidden>
Date: 2021-12-16 20:07:48

From: Vadim Fedorenko <redacted>

Monitoring of clock variance could be done through checking
the offset and the drift updates that are applied to atomic
clocks. Expose these values as attributes for timecard.

Signed-off-by: Vadim Fedorenko <redacted>
Signed-off-by: Jonathan Lemon <redacted>
---
 drivers/ptp/ptp_ocp.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
index 17ad5f0d13b2..2ac5ef54fada 100644
--- a/drivers/ptp/ptp_ocp.c
+++ b/drivers/ptp/ptp_ocp.c

@@ -52,6 +52,8 @@ struct ocp_reg {
 	u32	servo_offset_i;
 	u32	servo_drift_p;
 	u32	servo_drift_i;
+	u32	status_offset;
+	u32	status_drift;
 };
 
 #define OCP_CTRL_ENABLE		BIT(0)

@@ -1974,6 +1976,36 @@ available_clock_sources_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(available_clock_sources);
 
+static ssize_t
+clock_status_drift_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct ptp_ocp *bp = dev_get_drvdata(dev);
+	u32 val;
+	int res;
+
+	val = ioread32(&bp->reg->status_drift);
+	res = (val & ~INT_MAX) ? -1 : 1;
+	res *= (val & INT_MAX);
+	return sysfs_emit(buf, "%d\n", res);
+}
+static DEVICE_ATTR_RO(clock_status_drift);
+
+static ssize_t
+clock_status_offset_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct ptp_ocp *bp = dev_get_drvdata(dev);
+	u32 val;
+	int res;
+
+	val = ioread32(&bp->reg->status_offset);
+	res = (val & ~INT_MAX) ? -1 : 1;
+	res *= (val & INT_MAX);
+	return sysfs_emit(buf, "%d\n", res);
+}
+static DEVICE_ATTR_RO(clock_status_offset);
+
 static struct attribute *timecard_attrs[] = {
 	&dev_attr_serialnum.attr,
 	&dev_attr_gnss_sync.attr,

@@ -1985,6 +2017,8 @@ static struct attribute *timecard_attrs[] = {
 	&dev_attr_sma4.attr,
 	&dev_attr_available_sma_inputs.attr,
 	&dev_attr_available_sma_outputs.attr,
+	&dev_attr_clock_status_drift.attr,
+	&dev_attr_clock_status_offset.attr,
 	&dev_attr_irig_b_mode.attr,
 	&dev_attr_utc_tai_offset.attr,
 	&dev_attr_ts_window_adjust.attr,

-- 
2.31.1

[PATCH 3/5] ptp: ocp: add tod_correction attribute

From: Jonathan Lemon <hidden>
Date: 2021-12-16 20:07:50

From: Vadim Fedorenko <redacted>

TOD correction register is used to compensate for leap seconds in
different domains. Export it as attribute with write access.

Signed-off-by: Vadim Fedorenko <redacted>
Signed-off-by: Jonathan Lemon <redacted>
---
 drivers/ptp/ptp_ocp.c | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
index 2ac5ef54fada..2383d1024f0f 100644
--- a/drivers/ptp/ptp_ocp.c
+++ b/drivers/ptp/ptp_ocp.c

@@ -2006,6 +2006,46 @@ clock_status_offset_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(clock_status_offset);
 
+static ssize_t
+tod_correction_show(struct device *dev,
+		    struct device_attribute *attr, char *buf)
+{
+	struct ptp_ocp *bp = dev_get_drvdata(dev);
+	u32 val;
+	int res;
+
+	val = ioread32(&bp->tod->adj_sec);
+	res = (val & ~INT_MAX) ? -1 : 1;
+	res *= (val & INT_MAX);
+	return sysfs_emit(buf, "%d\n", res);
+}
+
+static ssize_t
+tod_correction_store(struct device *dev, struct device_attribute *attr,
+		     const char *buf, size_t count)
+{
+	struct ptp_ocp *bp = dev_get_drvdata(dev);
+	unsigned long flags;
+	int err, res;
+	u32 val = 0;
+
+	err = kstrtos32(buf, 0, &res);
+	if (err)
+		return err;
+	if (res < 0) {
+		res *= -1;
+		val |= BIT(31);
+	}
+	val |= res;
+
+	spin_lock_irqsave(&bp->lock, flags);
+	iowrite32(val, &bp->tod->adj_sec);
+	spin_unlock_irqrestore(&bp->lock, flags);
+
+	return count;
+}
+static DEVICE_ATTR_RW(tod_correction);
+
 static struct attribute *timecard_attrs[] = {
 	&dev_attr_serialnum.attr,
 	&dev_attr_gnss_sync.attr,

@@ -2022,6 +2062,7 @@ static struct attribute *timecard_attrs[] = {
 	&dev_attr_irig_b_mode.attr,
 	&dev_attr_utc_tai_offset.attr,
 	&dev_attr_ts_window_adjust.attr,
+	&dev_attr_tod_correction.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(timecard);

-- 
2.31.1

[PATCH 4/5] ptp: ocp: adjust utc_tai_offset to TOD info

From: Jonathan Lemon <hidden>
Date: 2021-12-16 20:07:50

From: Vadim Fedorenko <redacted>

utc_tai_offset is used to correct IRIG, DCF and NMEA outputs and is
set during initialisation but is not corrected during leap second
announce event. Add watchdog code to control this correction.

Signed-off-by: Vadim Fedorenko <redacted>
Signed-off-by: Jonathan Lemon <redacted>
---
 drivers/ptp/ptp_ocp.c | 51 ++++++++++++++++++++++++++-----------------
 1 file changed, 31 insertions(+), 20 deletions(-)

diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
index 2383d1024f0f..dc4d07b04320 100644
--- a/drivers/ptp/ptp_ocp.c
+++ b/drivers/ptp/ptp_ocp.c

@@ -761,12 +761,31 @@ __ptp_ocp_clear_drift_locked(struct ptp_ocp *bp)
 	iowrite32(select >> 16, &bp->reg->select);
 }
 
+static void
+ptp_ocp_utc_distribute(struct ptp_ocp *bp, u32 val)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&bp->lock, flags);
+
+	bp->utc_tai_offset = val;
+
+	if (bp->irig_out)
+		iowrite32(val, &bp->irig_out->adj_sec);
+	if (bp->dcf_out)
+		iowrite32(val, &bp->dcf_out->adj_sec);
+	if (bp->nmea_out)
+		iowrite32(val, &bp->nmea_out->adj_sec);
+
+	spin_unlock_irqrestore(&bp->lock, flags);
+}
+
 static void
 ptp_ocp_watchdog(struct timer_list *t)
 {
 	struct ptp_ocp *bp = from_timer(bp, t, watchdog);
 	unsigned long flags;
-	u32 status;
+	u32 status, utc_offset;
 
 	status = ioread32(&bp->pps_to_clk->status);

@@ -783,6 +802,17 @@ ptp_ocp_watchdog(struct timer_list *t)
 		bp->gnss_lost = 0;
 	}
 
+	/* if GNSS provides correct data we can rely on
+	 * it to get leap second information
+	 */
+	if (bp->tod) {
+		status = ioread32(&bp->tod->utc_status);
+		utc_offset = status & TOD_STATUS_UTC_MASK;
+		if (status & TOD_STATUS_UTC_VALID &&
+		    utc_offset != bp->utc_tai_offset)
+			ptp_ocp_utc_distribute(bp, utc_offset);
+	}
+
 	mod_timer(&bp->watchdog, jiffies + HZ);
 }

@@ -851,25 +881,6 @@ ptp_ocp_init_clock(struct ptp_ocp *bp)
 	return 0;
 }
 
-static void
-ptp_ocp_utc_distribute(struct ptp_ocp *bp, u32 val)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&bp->lock, flags);
-
-	bp->utc_tai_offset = val;
-
-	if (bp->irig_out)
-		iowrite32(val, &bp->irig_out->adj_sec);
-	if (bp->dcf_out)
-		iowrite32(val, &bp->dcf_out->adj_sec);
-	if (bp->nmea_out)
-		iowrite32(val, &bp->nmea_out->adj_sec);
-
-	spin_unlock_irqrestore(&bp->lock, flags);
-}
-
 static void
 ptp_ocp_tod_init(struct ptp_ocp *bp)
 {

-- 
2.31.1

[PATCH 5/5] ptp: ocp: export board info via devlink

From: Jonathan Lemon <hidden>
Date: 2021-12-16 20:07:55

TimeCard has eeprom with manufacturer pre-defined information.
Export this via devlink interface.

Co-developed-by: Vadim Fedorenko <redacted>
Signed-off-by: Jonathan Lemon <redacted>
---
 drivers/ptp/ptp_ocp.c | 71 +++++++++++++++++++++++++++++++------------
 1 file changed, 52 insertions(+), 19 deletions(-)

diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
index dc4d07b04320..8f235eef7521 100644
--- a/drivers/ptp/ptp_ocp.c
+++ b/drivers/ptp/ptp_ocp.c

@@ -203,6 +203,10 @@ struct ptp_ocp_ext_src {
 	int			irq_vec;
 };
 
+#define OCP_BOARD_MFR_LEN		8
+#define OCP_BOARD_ID_LEN		12
+#define OCP_SERIAL_LEN			6
+
 struct ptp_ocp {
 	struct pci_dev		*pdev;
 	struct device		dev;

@@ -237,8 +241,10 @@ struct ptp_ocp {
 	int			gnss2_port;
 	int			mac_port;	/* miniature atomic clock */
 	int			nmea_port;
-	u8			serial[6];
-	bool			has_serial;
+	u8			board_mfr[OCP_BOARD_MFR_LEN];
+	u8			board_id[OCP_BOARD_ID_LEN];
+	u8			serial[OCP_SERIAL_LEN];
+	bool			has_eeprom_data;
 	u32			pps_req_map;
 	int			flash_start;
 	u32			utc_tai_offset;

@@ -977,7 +983,7 @@ ptp_ocp_read_i2c(struct i2c_adapter *adap, u8 addr, u8 reg, u8 sz, u8 *data)
 }
 
 static void
-ptp_ocp_get_serial_number(struct ptp_ocp *bp)
+ptp_ocp_read_eeprom(struct ptp_ocp *bp)
 {
 	struct i2c_adapter *adap;
 	struct device *dev;

@@ -999,16 +1005,30 @@ ptp_ocp_get_serial_number(struct ptp_ocp *bp)
 		goto out;
 	}
 
-	err = ptp_ocp_read_i2c(adap, 0x58, 0x9A, 6, bp->serial);
-	if (err) {
-		dev_err(&bp->pdev->dev, "could not read eeprom: %d\n", err);
-		goto out;
-	}
+	err = ptp_ocp_read_i2c(adap, 0x50, 0x7A,
+			       sizeof(bp->board_mfr), bp->board_mfr);
+	if (err)
+		goto read_fail;
 
-	bp->has_serial = true;
+	err = ptp_ocp_read_i2c(adap, 0x50, 0x44,
+			       sizeof(bp->board_id), bp->board_id);
+	if (err)
+		goto read_fail;
+
+	err = ptp_ocp_read_i2c(adap, 0x58, 0x9A,
+			       sizeof(bp->serial), bp->serial);
+	if (err)
+		goto read_fail;
+
+	bp->has_eeprom_data = true;
 
 out:
 	put_device(dev);
+	return;
+
+read_fail:
+	dev_err(&bp->pdev->dev, "could not read eeprom: %d\n", err);
+	goto out;
 }
 
 static struct device *

@@ -1127,16 +1147,29 @@ ptp_ocp_devlink_info_get(struct devlink *devlink, struct devlink_info_req *req,
 			return err;
 	}
 
-	if (!bp->has_serial)
-		ptp_ocp_get_serial_number(bp);
-
-	if (bp->has_serial) {
-		sprintf(buf, "%pM", bp->serial);
-		err = devlink_info_serial_number_put(req, buf);
-		if (err)
-			return err;
+	if (!bp->has_eeprom_data) {
+		ptp_ocp_read_eeprom(bp);
+		if (!bp->has_eeprom_data)
+			return 0;
 	}
 
+	sprintf(buf, "%pM", bp->serial);
+	err = devlink_info_serial_number_put(req, buf);
+	if (err)
+		return err;
+
+	err = devlink_info_version_fixed_put(req,
+			DEVLINK_INFO_VERSION_GENERIC_BOARD_MANUFACTURE,
+			bp->board_mfr);
+	if (err)
+		return err;
+
+	err = devlink_info_version_fixed_put(req,
+			DEVLINK_INFO_VERSION_GENERIC_BOARD_ID,
+			bp->board_id);
+	if (err)
+		return err;
+
 	return 0;
 }

@@ -1828,8 +1861,8 @@ serialnum_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct ptp_ocp *bp = dev_get_drvdata(dev);
 
-	if (!bp->has_serial)
-		ptp_ocp_get_serial_number(bp);
+	if (!bp->has_eeprom_data)
+		ptp_ocp_read_eeprom(bp);
 
 	return sysfs_emit(buf, "%pM\n", bp->serial);
 }

-- 
2.31.1

Re: [PATCH 1/5] ptp: ocp: Add ptp_ocp_adjtime_coarse for large adjustments

From: Jakub Kicinski <kuba@kernel.org>
Date: 2021-12-18 03:10:12

On Thu, 16 Dec 2021 12:01:00 -0800 Jonathan Lemon wrote:

In ("ptp: ocp: Have FPGA fold in ns adjustment for adjtime."), the
ns adjustment was written to the FPGA register, so the clock could
accurately perform adjustments.

However, the adjtime() call passes in a s64, while the clock adjustment
registers use a s32.  When trying to perform adjustments with a large
value (37 sec), things fail.

Examine the incoming delta, and if larger than 1 sec, use the original
(coarse) adjustment method.  If smaller than 1 sec, then allow the
FPGA to fold in the changes over a 1 second window.

Fixes: 2d97ed56f671 ("ptp: ocp: Have FPGA fold in ns adjustment for adjtime.")

This SHA does not exist upstream. Please separate the fixes from the
features. Please CC Richard on the patches.

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