[PATCH net-next 0/4] dpll: zl3073x: add PTP clock support

[PATCH net-next 0/4] dpll: zl3073x: add PTP clock support

[Ivan Vecera]

Add PTP hardware clock support to the zl3073x DPLL driver.

Patch 1 adds channel ToD read/write, phase step and delta frequency
offset operations as low-level building blocks for PTP callbacks.

Patch 2 registers a PTP clock device for each DPLL channel with
gettimex64, settime64, adjtime, adjfine and perout callbacks.
The adjtime callback splits multi-second adjustments via ToD
read-modify-write and sub-second remainders via output phase step.

Patch 3 adds a channel TIE (Time Interval Error) write operation
for sub-picosecond resolution phase adjustment.

Patch 4 adds PTP adjphase and getmaxphase callbacks using TIE write
for phase adjustment in AUTO and REFLOCK modes, extends adjtime to
handle non-NCO modes via TIE write, and removes the NCO-only gate
from PTP clock registration.

Ivan Vecera (4):
  dpll: zl3073x: add channel ToD and phase step operations
  dpll: zl3073x: add PTP clock support
  dpll: zl3073x: add channel TIE write operation
  dpll: zl3073x: add PTP clock adjphase and TIE support

 drivers/dpll/zl3073x/Kconfig |   6 +-
 drivers/dpll/zl3073x/chan.c  | 307 +++++++++++++++++++
 drivers/dpll/zl3073x/chan.h  |  48 +++
 drivers/dpll/zl3073x/core.c  |   8 +
 drivers/dpll/zl3073x/core.h  |   8 +
 drivers/dpll/zl3073x/dpll.c  | 575 +++++++++++++++++++++++++++++++++--
 drivers/dpll/zl3073x/dpll.h  |   6 +
 drivers/dpll/zl3073x/regs.h  |  56 ++++
 8 files changed, 978 insertions(+), 36 deletions(-)


base-commit: 4a13f31a92f35161b499bf29638336885259da78
-- 
2.53.0

[PATCH net-next 1/4] dpll: zl3073x: add channel ToD and phase step operations

[Ivan Vecera]

Add low-level DPLL channel operations for ToD read/write/adjust,
delta frequency offset write and output phase step. ToD operations
use a wait-before-write pattern to avoid blocking after each
operation. tod_adjust additionally waits for completion since callers
may follow with phase step operations.

The tod_ready_wait helper selects the poll timeout based on the
current ToD command - write operations use a longer timeout (1000 ms)
than reads (30 ms).

The ToD read captures system timestamps (ptp_system_timestamp) around
the HW command and completion poll to support cross-timestamping.

Add output step-time mask invariant to zl3073x_chan and
zl3073x_chan_is_out_stepped() helper to check if an output
participates in step-time operations.

Tested-by: Chris du Quesnay <Chris.duQuesnay@microchip.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
 drivers/dpll/zl3073x/chan.c | 267 ++++++++++++++++++++++++++++++++++++
 drivers/dpll/zl3073x/chan.h |  31 +++++
 drivers/dpll/zl3073x/core.c |   4 +
 drivers/dpll/zl3073x/core.h |   5 +
 drivers/dpll/zl3073x/regs.h |  44 ++++++
 5 files changed, 351 insertions(+)

diff --git a/drivers/dpll/zl3073x/chan.c b/drivers/dpll/zl3073x/chan.c
index 4ec2cf53dad46..8360444559d09 100644
--- a/drivers/dpll/zl3073x/chan.c
+++ b/drivers/dpll/zl3073x/chan.c
@@ -3,6 +3,7 @@
 #include <linux/cleanup.h>
 #include <linux/delay.h>
 #include <linux/dev_printk.h>
+#include <linux/ptp_clock_kernel.h>
 #include <linux/string.h>
 #include <linux/types.h>
 
@@ -202,6 +203,11 @@ int zl3073x_chan_state_fetch(struct zl3073x_dev *zldev, u8 index)
 		zl3073x_chan_refsel_state_get(chan),
 		zl3073x_chan_refsel_ref_get(chan));
 
+	rc = zl3073x_read_u16(zldev, ZL_REG_OUTPUT_STEP_TIME_MASK,
+			      &chan->out_step_time_mask);
+	if (rc)
+		return rc;
+
 	guard(mutex)(&zldev->multiop_lock);
 
 	/* Read DPLL configuration from mailbox */
@@ -234,6 +240,267 @@ const struct zl3073x_chan *zl3073x_chan_state_get(struct zl3073x_dev *zldev,
 	return &zldev->chan[index];
 }
 
+/**
+ * zl3073x_chan_tod_ready_wait - wait for ToD semaphore to clear
+ * @zldev: pointer to zl3073x device
+ * @ch: DPLL channel index
+ *
+ * Polls the ToD control register until the semaphore bit is cleared,
+ * indicating the device has completed the previous ToD operation.
+ *
+ * Return: 0 on success, -EBUSY if semaphore not cleared, <0 on error
+ */
+static int zl3073x_chan_tod_ready_wait(struct zl3073x_dev *zldev, u8 ch)
+{
+	unsigned int timeout;
+	u8 tod_ctrl;
+	int rc;
+
+	rc = zl3073x_read_u8(zldev, ZL_REG_DPLL_TOD_CTRL(ch), &tod_ctrl);
+	if (rc)
+		return rc;
+
+	switch (FIELD_GET(ZL_DPLL_TOD_CTRL_CMD, tod_ctrl)) {
+	case ZL_DPLL_TOD_CTRL_CMD_WR_NEXT_1HZ:
+		timeout = ZL_POLL_TOD_WR_TIMEOUT_US;
+		break;
+	default:
+		timeout = ZL_POLL_TOD_RD_TIMEOUT_US;
+		break;
+	}
+
+	rc = zl3073x_poll_zero_u8(zldev, ZL_REG_DPLL_TOD_CTRL(ch),
+				  ZL_DPLL_TOD_CTRL_SEM, timeout);
+
+	return rc == -ETIMEDOUT ? -EBUSY : rc;
+}
+
+/**
+ * zl3073x_chan_tod_ctrl - issue ToD command
+ * @zldev: pointer to zl3073x device
+ * @ch: DPLL channel index
+ * @cmd: ToD command to execute
+ *
+ * Writes the semaphore and command to dpll_tod_ctrl. The caller must
+ * ensure the device is ready (semaphore clear) before calling and
+ * must wait for completion if needed.
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int zl3073x_chan_tod_ctrl(struct zl3073x_dev *zldev, u8 ch, u8 cmd)
+{
+	return zl3073x_write_u8(zldev, ZL_REG_DPLL_TOD_CTRL(ch),
+				ZL_DPLL_TOD_CTRL_SEM | cmd);
+}
+
+/**
+ * zl3073x_chan_tod_read - read ToD registers after issuing a command
+ * @zldev: pointer to zl3073x device
+ * @ch: DPLL channel index
+ * @next_hz: if true, read predicted ToD at next 1 Hz; otherwise read current
+ * @ts: timespec to store the result
+ * @sts: optional system timestamp pair for cross-timestamping
+ *
+ * Context: Caller must serialize all zl3073x_chan_tod_* calls externally.
+ * Return: 0 on success, <0 on error
+ */
+int zl3073x_chan_tod_read(struct zl3073x_dev *zldev, u8 ch,
+			  bool next_hz, struct timespec64 *ts,
+			  struct ptp_system_timestamp *sts)
+{
+	u32 nsec;
+	u64 sec;
+	u8 cmd;
+	int rc;
+
+	if (next_hz)
+		cmd = ZL_DPLL_TOD_CTRL_CMD_RD_NEXT_1HZ;
+	else
+		cmd = ZL_DPLL_TOD_CTRL_CMD_RD_CURRENT;
+
+	/* Wait for any previous ToD operation to complete */
+	rc = zl3073x_chan_tod_ready_wait(zldev, ch);
+	if (rc)
+		return rc;
+
+	ptp_read_system_prets(sts);
+	rc = zl3073x_chan_tod_ctrl(zldev, ch, cmd);
+	if (rc)
+		return rc;
+
+	rc = zl3073x_chan_tod_ready_wait(zldev, ch);
+	if (rc)
+		return rc;
+	ptp_read_system_postts(sts);
+
+	rc = zl3073x_read_u48(zldev, ZL_REG_DPLL_TOD_SEC(ch), &sec);
+	if (rc)
+		return rc;
+
+	/* HW nanoseconds are always in [0, NSEC_PER_SEC) range */
+	rc = zl3073x_read_u32(zldev, ZL_REG_DPLL_TOD_NS(ch), &nsec);
+	if (rc)
+		return rc;
+
+	ts->tv_sec = sec;
+	ts->tv_nsec = nsec;
+
+	return 0;
+}
+
+/**
+ * zl3073x_chan_tod_write - write ToD registers and trigger 1 Hz update
+ * @zldev: pointer to zl3073x device
+ * @ch: DPLL channel index
+ * @ts: time to set
+ *
+ * Context: Caller must serialize all zl3073x_chan_tod_* calls externally.
+ * Return: 0 on success, <0 on error
+ */
+int zl3073x_chan_tod_write(struct zl3073x_dev *zldev, u8 ch,
+			   struct timespec64 ts)
+{
+	int rc;
+
+	/* Wait for any previous ToD operation to complete */
+	rc = zl3073x_chan_tod_ready_wait(zldev, ch);
+	if (rc)
+		return rc;
+
+	rc = zl3073x_write_u48(zldev, ZL_REG_DPLL_TOD_SEC(ch), ts.tv_sec);
+	if (rc)
+		return rc;
+
+	rc = zl3073x_write_u32(zldev, ZL_REG_DPLL_TOD_NS(ch), ts.tv_nsec);
+	if (rc)
+		return rc;
+
+	return zl3073x_chan_tod_ctrl(zldev, ch,
+				    ZL_DPLL_TOD_CTRL_CMD_WR_NEXT_1HZ);
+}
+
+/**
+ * zl3073x_chan_tod_adjust - atomic ToD read-modify-write with rollover guard
+ * @zldev: pointer to zl3073x device
+ * @ch: DPLL channel index
+ * @delta: time adjustment to apply
+ *
+ * Reads the next-Hz ToD and current ToD, then checks whether enough time
+ * remains before the next 1 Hz rollover to safely complete the write.
+ * If less than 20 ms remains, waits for the rollover and increments the
+ * next-Hz seconds by one. Applies @delta and writes the result back.
+ *
+ * Context: Caller must serialize all zl3073x_chan_tod_* calls externally.
+ * Return: 0 on success, <0 on error
+ */
+int zl3073x_chan_tod_adjust(struct zl3073x_dev *zldev, u8 ch,
+			    struct timespec64 delta)
+{
+	static const long threshold_ns = 20 * NSEC_PER_MSEC;
+	struct timespec64 ts_next, ts_cur, diff;
+	int rc;
+
+	/* Read predicted ToD at next 1 Hz tick */
+	rc = zl3073x_chan_tod_read(zldev, ch, true, &ts_next, NULL);
+	if (rc)
+		return rc;
+
+	/* Read current ToD to determine remaining margin */
+	rc = zl3073x_chan_tod_read(zldev, ch, false, &ts_cur, NULL);
+	if (rc)
+		return rc;
+
+	/* If too close to (or past) the next rollover, wait it out */
+	diff = timespec64_sub(ts_next, ts_cur);
+	if (diff.tv_sec < 0 || (!diff.tv_sec && diff.tv_nsec < threshold_ns)) {
+		if (!diff.tv_sec && diff.tv_nsec)
+			fsleep((unsigned long)diff.tv_nsec / NSEC_PER_USEC + 1);
+		ts_next.tv_sec++;
+	}
+
+	/* Apply delta to the next-Hz ToD */
+	ts_next = timespec64_add(ts_next, delta);
+	if (!timespec64_valid(&ts_next))
+		return -EINVAL;
+
+	/* Write adjusted ToD back and wait for completion */
+	rc = zl3073x_chan_tod_write(zldev, ch, ts_next);
+	if (rc)
+		return rc;
+
+	return zl3073x_chan_tod_ready_wait(zldev, ch);
+}
+
+/**
+ * zl3073x_chan_df_offset_set - write delta frequency offset to hardware
+ * @zldev: pointer to zl3073x device
+ * @ch: DPLL channel index
+ * @offset: frequency offset in 2^-48 steps
+ *
+ * Return: 0 on success, <0 on error
+ */
+int zl3073x_chan_df_offset_set(struct zl3073x_dev *zldev, u8 ch, s64 offset)
+{
+	int rc;
+
+	rc = zl3073x_write_u48(zldev, ZL_REG_DPLL_DF_OFFSET(ch), offset);
+	if (!rc)
+		zldev->chan[ch].df_offset = offset;
+
+	return rc;
+}
+
+/**
+ * zl3073x_chan_phase_step - execute one output phase step operation
+ * @zldev: pointer to zl3073x device
+ * @ch: DPLL channel index
+ * @out_mask: bitmask of outputs to step
+ * @step_cycles: phase step in synthesizer clock cycles
+ * @tod_step: also step the ToD counter
+ *
+ * All masked outputs must use synthesizers of the same frequency since
+ * the step value is in synthesizer clock cycles.
+ *
+ * Return: 0 on success, <0 on error
+ */
+int zl3073x_chan_phase_step(struct zl3073x_dev *zldev, u8 ch,
+			    u16 out_mask, s32 step_cycles,
+			    bool tod_step)
+{
+	u8 ctrl;
+	int rc;
+
+	guard(mutex)(&zldev->phase_step_lock);
+
+	/* Wait for any previous phase step operation to complete */
+	rc = zl3073x_poll_zero_u8(zldev, ZL_REG_OUTPUT_PHASE_STEP_CTRL,
+				  ZL_OUTPUT_PHASE_STEP_CTRL_OP,
+				  ZL_POLL_PHASE_STEP_TIMEOUT_US);
+	if (rc)
+		return rc;
+
+	rc = zl3073x_write_u32(zldev, ZL_REG_OUTPUT_PHASE_STEP_DATA,
+			       step_cycles);
+	if (rc)
+		return rc;
+
+	rc = zl3073x_write_u16(zldev, ZL_REG_OUTPUT_PHASE_STEP_MASK, out_mask);
+	if (rc)
+		return rc;
+
+	rc = zl3073x_write_u8(zldev, ZL_REG_OUTPUT_PHASE_STEP_NUMBER, 1);
+	if (rc)
+		return rc;
+
+	ctrl = FIELD_PREP(ZL_OUTPUT_PHASE_STEP_CTRL_DPLL, ch) |
+	       FIELD_PREP(ZL_OUTPUT_PHASE_STEP_CTRL_OP,
+			  ZL_OUTPUT_PHASE_STEP_CTRL_OP_WRITE);
+	if (tod_step)
+		ctrl |= ZL_OUTPUT_PHASE_STEP_CTRL_TOD_STEP;
+
+	return zl3073x_write_u8(zldev, ZL_REG_OUTPUT_PHASE_STEP_CTRL, ctrl);
+}
+
 /**
  * zl3073x_chan_state_set - commit DPLL channel state changes to hardware
  * @zldev: pointer to zl3073x_dev structure
diff --git a/drivers/dpll/zl3073x/chan.h b/drivers/dpll/zl3073x/chan.h
index dc9c6d95bdee7..56a3db012cf50 100644
--- a/drivers/dpll/zl3073x/chan.h
+++ b/drivers/dpll/zl3073x/chan.h
@@ -5,10 +5,12 @@
 
 #include <linux/bitfield.h>
 #include <linux/stddef.h>
+#include <linux/time64.h>
 #include <linux/types.h>
 
 #include "regs.h"
 
+struct ptp_system_timestamp;
 struct zl3073x_dev;
 
 /**
@@ -16,6 +18,7 @@ struct zl3073x_dev;
  * @ctrl: DPLL control register value
  * @mode_refsel: mode and reference selection register value
  * @ref_prio: reference priority registers (4 bits per ref, P/N packed)
+ * @out_step_time_mask: output step-time mask
  * @mon_status: monitor status register value
  * @refsel_status: reference selection status register value
  * @df_offset: frequency offset vs tracked reference in 2^-48 steps
@@ -26,6 +29,9 @@ struct zl3073x_chan {
 		u8	mode_refsel;
 		u8	ref_prio[ZL3073X_NUM_REFS / 2];
 	);
+	struct_group(inv, /* Invariants */
+		u16	out_step_time_mask;
+	);
 	struct_group(stat,
 		u8	mon_status;
 		u8	refsel_status;
@@ -42,6 +48,18 @@ int zl3073x_chan_state_set(struct zl3073x_dev *zldev, u8 index,
 int zl3073x_chan_state_update(struct zl3073x_dev *zldev, u8 index);
 int zl3073x_chan_nco_mode_set(struct zl3073x_dev *zldev, u8 index);
 
+int zl3073x_chan_tod_read(struct zl3073x_dev *zldev, u8 ch,
+			  bool next_hz, struct timespec64 *ts,
+			  struct ptp_system_timestamp *sts);
+int zl3073x_chan_tod_write(struct zl3073x_dev *zldev, u8 ch,
+			   struct timespec64 ts);
+int zl3073x_chan_tod_adjust(struct zl3073x_dev *zldev, u8 ch,
+			    struct timespec64 delta);
+int zl3073x_chan_phase_step(struct zl3073x_dev *zldev, u8 ch,
+			    u16 out_mask, s32 step_cycles, bool tod_step);
+
+int zl3073x_chan_df_offset_set(struct zl3073x_dev *zldev, u8 ch, s64 offset);
+
 /**
  * zl3073x_chan_df_offset_get - get cached df_offset vs tracked reference
  * @chan: pointer to channel state
@@ -233,4 +251,17 @@ static inline u8 zl3073x_chan_refsel_ref_get(const struct zl3073x_chan *chan)
 	return FIELD_GET(ZL_DPLL_REFSEL_STATUS_REFSEL, chan->refsel_status);
 }
 
+/**
+ * zl3073x_chan_is_out_stepped - check if output is in step-time mask
+ * @chan: pointer to channel state
+ * @out: output index
+ *
+ * Return: true if output is affected by step-time operations
+ */
+static inline bool
+zl3073x_chan_is_out_stepped(const struct zl3073x_chan *chan, u8 out)
+{
+	return !!(chan->out_step_time_mask & BIT(out));
+}
+
 #endif /* _ZL3073X_CHAN_H */
diff --git a/drivers/dpll/zl3073x/core.c b/drivers/dpll/zl3073x/core.c
index 7f5afaaae6342..958b722d7a38d 100644
--- a/drivers/dpll/zl3073x/core.c
+++ b/drivers/dpll/zl3073x/core.c
@@ -1033,6 +1033,10 @@ int zl3073x_dev_probe(struct zl3073x_dev *zldev)
 	 * and/or polls are required to be done atomically.
 	 */
 	rc = devm_mutex_init(zldev->dev, &zldev->multiop_lock);
+	if (rc)
+		return dev_err_probe(zldev->dev, rc,
+				     "Failed to initialize mutex\n");
+	rc = devm_mutex_init(zldev->dev, &zldev->phase_step_lock);
 	if (rc)
 		return dev_err_probe(zldev->dev, rc,
 				     "Failed to initialize mutex\n");
diff --git a/drivers/dpll/zl3073x/core.h b/drivers/dpll/zl3073x/core.h
index 78dc208f3eea2..bd60104ee567a 100644
--- a/drivers/dpll/zl3073x/core.h
+++ b/drivers/dpll/zl3073x/core.h
@@ -26,6 +26,9 @@ struct zl3073x_dpll;
 #define ZL_POLL_HWREG_TIMEOUT_US	(50 * USEC_PER_MSEC)
 #define ZL_POLL_MB_TIMEOUT_US		(30 * USEC_PER_MSEC)
 #define ZL_POLL_PHASE_ERR_TIMEOUT_US	(50 * USEC_PER_MSEC)
+#define ZL_POLL_PHASE_STEP_TIMEOUT_US	(3000 * USEC_PER_MSEC)
+#define ZL_POLL_TOD_RD_TIMEOUT_US	(30 * USEC_PER_MSEC)
+#define ZL_POLL_TOD_WR_TIMEOUT_US	(1000 * USEC_PER_MSEC)
 
 enum zl3073x_flags {
 	ZL3073X_FLAG_REF_PHASE_COMP_32_BIT,
@@ -55,6 +58,7 @@ struct zl3073x_chip_info {
  * @regmap: regmap to access device registers
  * @info: detected chip info
  * @multiop_lock: to serialize multiple register operations
+ * @phase_step_lock: to serialize output phase step operations
  * @ref: array of input references' invariants
  * @out: array of outs' invariants
  * @synth: array of synths' invariants
@@ -71,6 +75,7 @@ struct zl3073x_dev {
 	struct regmap			*regmap;
 	const struct zl3073x_chip_info	*info;
 	struct mutex			multiop_lock;
+	struct mutex			phase_step_lock;
 
 	/* Invariants */
 	struct zl3073x_ref	ref[ZL3073X_NUM_REFS];
diff --git a/drivers/dpll/zl3073x/regs.h b/drivers/dpll/zl3073x/regs.h
index b70ead7d4495b..9b8e06fddaa6c 100644
--- a/drivers/dpll/zl3073x/regs.h
+++ b/drivers/dpll/zl3073x/regs.h
@@ -179,6 +179,14 @@
 #define ZL_DPLL_DF_READ_CMD			GENMASK(2, 0)
 #define ZL_DPLL_DF_READ_CMD_ACC_I		4
 
+#define ZL_REG_DPLL_TOD_CTRL(_idx)					\
+	ZL_REG_IDX(_idx, 5, 0x38, 1, 8, 1)
+#define ZL_DPLL_TOD_CTRL_SEM			BIT(4)
+#define ZL_DPLL_TOD_CTRL_CMD			GENMASK(3, 0)
+#define ZL_DPLL_TOD_CTRL_CMD_WR_NEXT_1HZ	1
+#define ZL_DPLL_TOD_CTRL_CMD_RD_CURRENT	8
+#define ZL_DPLL_TOD_CTRL_CMD_RD_NEXT_1HZ	9
+
 #define ZL_REG_DPLL_MEAS_CTRL			ZL_REG(5, 0x50, 1)
 #define ZL_DPLL_MEAS_CTRL_EN			BIT(0)
 #define ZL_DPLL_MEAS_CTRL_AVG_FACTOR		GENMASK(7, 4)
@@ -193,6 +201,9 @@
 
 /*******************************
  * Register Pages 6-7, DPLL Data
+ *
+ * Per-channel registers with stride 0x20. Channels 0-3 reside on page 6,
+ * channel 4 on page 7.
  *******************************/
 
 #define ZL_REG_DPLL_DF_OFFSET_03(_idx)					\
@@ -202,6 +213,18 @@
 	((_idx) < 4 ? ZL_REG_DPLL_DF_OFFSET_03(_idx) : ZL_REG_DPLL_DF_OFFSET_4)
 #define ZL_DPLL_DF_OFFSET_UNKNOWN	S64_MIN
 
+#define ZL_REG_DPLL_TOD_SEC_03(_idx)					\
+	ZL_REG_IDX(_idx, 6, 0x12, 6, 4, 0x20)
+#define ZL_REG_DPLL_TOD_SEC_4			ZL_REG(7, 0x12, 6)
+#define ZL_REG_DPLL_TOD_SEC(_idx)					\
+	((_idx) < 4 ? ZL_REG_DPLL_TOD_SEC_03(_idx) : ZL_REG_DPLL_TOD_SEC_4)
+
+#define ZL_REG_DPLL_TOD_NS_03(_idx)					\
+	ZL_REG_IDX(_idx, 6, 0x18, 4, 4, 0x20)
+#define ZL_REG_DPLL_TOD_NS_4			ZL_REG(7, 0x18, 4)
+#define ZL_REG_DPLL_TOD_NS(_idx)					\
+	((_idx) < 4 ? ZL_REG_DPLL_TOD_NS_03(_idx) : ZL_REG_DPLL_TOD_NS_4)
+
 /***********************************
  * Register Page 9, Synth and Output
  ***********************************/
@@ -221,6 +244,8 @@
 #define ZL_OUTPUT_CTRL_EN			BIT(0)
 #define ZL_OUTPUT_CTRL_SYNTH_SEL		GENMASK(6, 4)
 
+#define ZL_REG_OUTPUT_STEP_TIME_MASK		ZL_REG(9, 0x36, 2)
+
 /*******************************
  * Register Page 10, Ref Mailbox
  *******************************/
@@ -316,6 +341,25 @@
 #define ZL_REG_OUTPUT_ESYNC_WIDTH		ZL_REG(14, 0x18, 4)
 #define ZL_REG_OUTPUT_PHASE_COMP		ZL_REG(14, 0x20, 4)
 
+/***********************************
+ * Register Page 9, Output Phase Step
+ ***********************************/
+
+#define ZL_REG_OUTPUT_PHASE_STEP_CTRL		ZL_REG(9, 0x38, 1)
+#define ZL_OUTPUT_PHASE_STEP_CTRL_DPLL		GENMASK(6, 4)
+#define ZL_OUTPUT_PHASE_STEP_CTRL_TOD_STEP	BIT(3)
+#define ZL_OUTPUT_PHASE_STEP_CTRL_OP		GENMASK(1, 0)
+#define ZL_OUTPUT_PHASE_STEP_CTRL_OP_NONE	0
+#define ZL_OUTPUT_PHASE_STEP_CTRL_OP_RESET	1
+#define ZL_OUTPUT_PHASE_STEP_CTRL_OP_READ	2
+#define ZL_OUTPUT_PHASE_STEP_CTRL_OP_WRITE	3
+
+#define ZL_REG_OUTPUT_PHASE_STEP_NUMBER		ZL_REG(9, 0x39, 1)
+
+#define ZL_REG_OUTPUT_PHASE_STEP_MASK		ZL_REG(9, 0x3a, 2)
+
+#define ZL_REG_OUTPUT_PHASE_STEP_DATA		ZL_REG(9, 0x3c, 4)
+
 /*
  * Register Page 255 - HW registers access
  */
-- 
2.53.0

[PATCH net-next 2/4] dpll: zl3073x: add PTP clock support

[Ivan Vecera]

Add PTP clock support for the ZL3073x DPLL driver. A PTP clock device
is registered for each DPLL channel that is in NCO mode, providing
gettimex64, settime64, adjtime, adjfine and perout callbacks.

The adjtime callback handles multi-second adjustments via ToD
read-modify-write at 1 Hz boundaries, with sub-second remainders
handled through the output phase step mechanism. If phase step is
unavailable, the full adjustment falls back to ToD read-modify-write.

Output pins eligible for periodic output (single-ended, marked in
output_step_time_mask, supporting 1 Hz) are registered as PTP perout
channels. Enabling perout sets the output frequency to 1 Hz via the
existing DPLL frequency_set path.

All PTP callbacks are serialized by the existing per-DPLL zldpll->lock
mutex, which is also used by DPLL pin and device callbacks.

Tested-by: Chris du Quesnay <Chris.duQuesnay@microchip.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
 drivers/dpll/zl3073x/Kconfig |   6 +-
 drivers/dpll/zl3073x/dpll.c  | 521 ++++++++++++++++++++++++++++++++---
 drivers/dpll/zl3073x/dpll.h  |   6 +
 3 files changed, 497 insertions(+), 36 deletions(-)

diff --git a/drivers/dpll/zl3073x/Kconfig b/drivers/dpll/zl3073x/Kconfig
index 5bbca14005813..d0574ad571d3f 100644
--- a/drivers/dpll/zl3073x/Kconfig
+++ b/drivers/dpll/zl3073x/Kconfig
@@ -2,7 +2,7 @@
 
 config ZL3073X
 	tristate "Microchip Azurite DPLL/PTP/SyncE devices" if COMPILE_TEST
-	depends on NET
+	depends on NET && PTP_1588_CLOCK_OPTIONAL
 	select DPLL
 	select NET_DEVLINK
 	select REGMAP
@@ -16,7 +16,7 @@ config ZL3073X
 
 config ZL3073X_I2C
 	tristate "I2C bus implementation for Microchip Azurite devices"
-	depends on I2C && NET
+	depends on I2C && NET && PTP_1588_CLOCK_OPTIONAL
 	select REGMAP_I2C
 	select ZL3073X
 	help
@@ -28,7 +28,7 @@ config ZL3073X_I2C
 
 config ZL3073X_SPI
 	tristate "SPI bus implementation for Microchip Azurite devices"
-	depends on NET && SPI
+	depends on NET && SPI && PTP_1588_CLOCK_OPTIONAL
 	select REGMAP_SPI
 	select ZL3073X
 	help
diff --git a/drivers/dpll/zl3073x/dpll.c b/drivers/dpll/zl3073x/dpll.c
index d91f52b58eae3..86770dea3d652 100644
--- a/drivers/dpll/zl3073x/dpll.c
+++ b/drivers/dpll/zl3073x/dpll.c
@@ -2,6 +2,7 @@
 
 #include <linux/bits.h>
 #include <linux/bitfield.h>
+#include <linux/cleanup.h>
 #include <linux/bug.h>
 #include <linux/container_of.h>
 #include <linux/dev_printk.h>
@@ -14,6 +15,7 @@
 #include <linux/netlink.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
+#include <linux/ptp_clock_kernel.h>
 #include <linux/slab.h>
 #include <linux/sprintf.h>
 
@@ -42,6 +44,7 @@
  * @phase_offset: last saved pin phase offset
  * @freq_offset: last saved fractional frequency offset
  * @measured_freq: last saved measured frequency
+ * @perout_idx: PTP perout channel index, or -1 if not perout-eligible
  */
 struct zl3073x_dpll_pin {
 	struct list_head	list;
@@ -59,6 +62,7 @@ struct zl3073x_dpll_pin {
 	s64			phase_offset;
 	s64			freq_offset;
 	u32			measured_freq;
+	s8			perout_idx;
 };
 
 /*
@@ -936,21 +940,17 @@ zl3073x_dpll_output_pin_frequency_get(const struct dpll_pin *dpll_pin,
 }
 
 static int
-zl3073x_dpll_output_pin_frequency_set(const struct dpll_pin *dpll_pin,
-				      void *pin_priv,
-				      const struct dpll_device *dpll,
-				      void *dpll_priv, u64 frequency,
-				      struct netlink_ext_ack *extack)
+__zl3073x_dpll_output_pin_frequency_set(struct zl3073x_dpll *zldpll,
+					struct zl3073x_dpll_pin *pin,
+					u64 frequency)
 {
-	struct zl3073x_dpll *zldpll = dpll_priv;
 	struct zl3073x_dev *zldev = zldpll->dev;
-	struct zl3073x_dpll_pin *pin = pin_priv;
 	const struct zl3073x_synth *synth;
 	u32 new_div, synth_freq;
 	struct zl3073x_out out;
 	u8 out_id;
 
-	guard(mutex)(&zldpll->lock);
+	lockdep_assert_held(&zldpll->lock);
 
 	out_id = zl3073x_output_pin_out_get(pin->id);
 	out = *zl3073x_out_state_get(zldev, out_id);
@@ -1011,6 +1011,21 @@ zl3073x_dpll_output_pin_frequency_set(const struct dpll_pin *dpll_pin,
 	return zl3073x_out_state_set(zldev, out_id, &out);
 }
 
+static int
+zl3073x_dpll_output_pin_frequency_set(const struct dpll_pin *dpll_pin,
+				      void *pin_priv,
+				      const struct dpll_device *dpll,
+				      void *dpll_priv, u64 frequency,
+				      struct netlink_ext_ack *extack)
+{
+	struct zl3073x_dpll *zldpll = dpll_priv;
+
+	guard(mutex)(&zldpll->lock);
+
+	return __zl3073x_dpll_output_pin_frequency_set(zldpll, pin_priv,
+						       frequency);
+}
+
 static int
 zl3073x_dpll_output_pin_phase_adjust_get(const struct dpll_pin *dpll_pin,
 					 void *pin_priv,
@@ -1608,6 +1623,7 @@ zl3073x_dpll_pin_alloc(struct zl3073x_dpll *zldpll, enum dpll_pin_direction dir,
 	pin->dpll = zldpll;
 	pin->dir = dir;
 	pin->id = id;
+	pin->perout_idx = -1;
 
 	return pin;
 }
@@ -1626,6 +1642,44 @@ zl3073x_dpll_pin_free(struct zl3073x_dpll_pin *pin)
 	kfree(pin);
 }
 
+/**
+ * zl3073x_dpll_pin_is_perout - check if output pin is perout-eligible
+ * @pin: DPLL pin to check
+ * @props: pin properties (already fetched by caller)
+ *
+ * An output pin is eligible for PTP periodic output if it is single-ended
+ * (not differential) and supports 1 Hz in its frequency list.
+ *
+ * Return: true if eligible, false otherwise
+ */
+static bool
+zl3073x_dpll_pin_is_perout(struct zl3073x_dpll_pin *pin,
+			   const struct zl3073x_pin_props *props)
+{
+	struct zl3073x_dpll *zldpll = pin->dpll;
+	const struct zl3073x_chan *chan;
+	u8 out_id;
+	int i;
+
+	if (zl3073x_dpll_is_input_pin(pin))
+		return false;
+
+	out_id = zl3073x_output_pin_out_get(pin->id);
+	if (zl3073x_dev_out_is_diff(zldpll->dev, out_id))
+		return false;
+
+	chan = zl3073x_chan_state_get(zldpll->dev, zldpll->id);
+	if (!zl3073x_chan_is_out_stepped(chan, out_id))
+		return false;
+
+	for (i = 0; i < props->dpll_props.freq_supported_num; i++) {
+		if (props->dpll_props.freq_supported[i].min == 1)
+			return true;
+	}
+
+	return false;
+}
+
 /**
  * zl3073x_dpll_pin_register - register DPLL pin
  * @pin: pointer to DPLL pin
@@ -1667,6 +1721,8 @@ zl3073x_dpll_pin_register(struct zl3073x_dpll_pin *pin, u32 index)
 		if (pin->prio == ZL_DPLL_REF_PRIO_NONE)
 			/* Clamp prio to max value */
 			pin->prio = ZL_DPLL_REF_PRIO_MAX;
+	} else if (zl3073x_dpll_pin_is_perout(pin, props)) {
+		pin->perout_idx = zldpll->ptp_info.n_per_out++;
 	}
 
 	/* Create or get existing DPLL pin */
@@ -1897,6 +1953,8 @@ zl3073x_dpll_pins_register(struct zl3073x_dpll *zldpll)
 	u8 id, index;
 	int rc;
 
+	zldpll->ptp_info.n_per_out = 0;
+
 	/* Process input pins */
 	for (index = 0; index < ZL3073X_NUM_PINS; index++) {
 		/* First input pins and then output pins */
@@ -2280,45 +2338,393 @@ zl3073x_dpll_init_fine_phase_adjust(struct zl3073x_dev *zldev)
 	return rc;
 }
 
+/* Maximum frequency adjustment: +-1% of nominal in ppb */
+#define ZL3073X_DPLL_PTP_MAX_ADJ	10000000
+
 /**
- * zl3073x_dpll_alloc - allocate DPLL device
- * @zldev: pointer to zl3073x device
- * @ch: DPLL channel number
+ * zl3073x_dpll_ptp_gettimex64 - read current time from ToD counters
+ * @info: PTP clock info
+ * @ts: timespec to store current time
+ * @sts: optional system timestamp pair for cross-timestamping
  *
- * Allocates DPLL device structure for given DPLL channel.
+ * Return: 0 on success, <0 on error
+ */
+static int zl3073x_dpll_ptp_gettimex64(struct ptp_clock_info *info,
+				       struct timespec64 *ts,
+				       struct ptp_system_timestamp *sts)
+{
+	struct zl3073x_dpll *zldpll = container_of(info, struct zl3073x_dpll,
+						   ptp_info);
+
+	guard(mutex)(&zldpll->lock);
+
+	return zl3073x_chan_tod_read(zldpll->dev, zldpll->id, false, ts, sts);
+}
+
+/**
+ * zl3073x_dpll_ptp_settime64 - set ToD counters to given time
+ * @info: PTP clock info
+ * @ts: timespec with time to set
  *
- * Return: pointer to DPLL device on success, error pointer on error
+ * Return: 0 on success, <0 on error
  */
-struct zl3073x_dpll *
-zl3073x_dpll_alloc(struct zl3073x_dev *zldev, u8 ch)
+static int zl3073x_dpll_ptp_settime64(struct ptp_clock_info *info,
+				      const struct timespec64 *ts)
 {
-	struct zl3073x_dpll *zldpll;
+	struct zl3073x_dpll *zldpll = container_of(info, struct zl3073x_dpll,
+						   ptp_info);
 
-	zldpll = kzalloc_obj(*zldpll);
-	if (!zldpll)
-		return ERR_PTR(-ENOMEM);
+	guard(mutex)(&zldpll->lock);
 
-	zldpll->dev = zldev;
-	zldpll->id = ch;
-	mutex_init(&zldpll->lock);
-	INIT_LIST_HEAD(&zldpll->pins);
+	return zl3073x_chan_tod_write(zldpll->dev, zldpll->id, *ts);
+}
 
-	return zldpll;
+/**
+ * zl3073x_dpll_ptp_adjtime_phase_step - adjust sub-second time via phase step
+ * @zldpll: DPLL channel
+ * @delta: time adjustment in nanoseconds (must be within (-NSEC_PER_SEC,
+ *         NSEC_PER_SEC))
+ *
+ * Uses the output phase step mechanism with tod_step=1 to adjust both
+ * the output clock phase and the ToD counter simultaneously. This keeps
+ * outputs and ToD coherent. Only valid in NCO mode.
+ *
+ * Outputs are grouped by synthesizer since the phase step value is in
+ * synthesizer clock cycles. The first synth group with enabled outputs
+ * uses tod_step to adjust both outputs and the ToD counter. Remaining
+ * groups step outputs only. If no synth has enabled outputs, the ToD
+ * counter is stepped alone using an empty output mask (the FW uses the
+ * lowest-ID synth's period for the conversion).
+ *
+ * Return: 0 on success, -EOPNOTSUPP if no synths available, <0 on error
+ */
+static int zl3073x_dpll_ptp_adjtime_phase_step(struct zl3073x_dpll *zldpll,
+					       s64 delta)
+{
+	u16 synth_mask[ZL3073X_NUM_SYNTHS] = {};
+	struct zl3073x_dev *zldev = zldpll->dev;
+	const struct zl3073x_synth *synth;
+	const struct zl3073x_chan *chan;
+	struct zl3073x_dpll_pin *pin;
+	u32 first_synth_freq = 0;
+	bool tod_stepped = false;
+	s32 step_cycles;
+	u32 synth_freq;
+	int rc;
+	u8 i;
+
+	chan = zl3073x_chan_state_get(zldev, zldpll->id);
+
+	/* Build per-synth output masks from registered output pins */
+	list_for_each_entry(pin, &zldpll->pins, list) {
+		u8 out_id, synth_id;
+
+		if (zl3073x_dpll_is_input_pin(pin))
+			continue;
+
+		out_id = zl3073x_output_pin_out_get(pin->id);
+
+		if (!zl3073x_chan_is_out_stepped(chan, out_id))
+			continue;
+
+		synth_id = zl3073x_dev_out_synth_get(zldev, out_id);
+		if (synth_id >= ZL3073X_NUM_SYNTHS) {
+			dev_warn(zldev->dev, "Unexpected synth id for OUT%u\n",
+				 out_id);
+			continue;
+		}
+		synth_mask[synth_id] |= BIT(out_id);
+	}
+
+	/* Process each synth group */
+	for (i = 0; i < ZL3073X_NUM_SYNTHS; i++) {
+		synth = zl3073x_synth_state_get(zldev, i);
+		if (!zl3073x_synth_is_enabled(synth) ||
+		    zl3073x_synth_dpll_get(synth) != zldpll->id)
+			continue;
+
+		synth_freq = zl3073x_synth_freq_get(synth);
+
+		/* Remember lowest-ID synth freq for ToD-only fallback */
+		if (!first_synth_freq)
+			first_synth_freq = synth_freq;
+
+		if (!synth_mask[i])
+			continue;
+
+		/* Safe for s32: max synth freq is 750 MHz */
+		step_cycles = div_s64(delta * synth_freq, NSEC_PER_SEC);
+
+		rc = zl3073x_chan_phase_step(zldev, zldpll->id,
+					     synth_mask[i], step_cycles,
+					     !tod_stepped);
+		if (rc) {
+			if (tod_stepped) {
+				dev_warn(zldev->dev,
+					 "Partial phase step failure\n");
+				return 0;
+			}
+			return rc;
+		}
+		tod_stepped = true;
+	}
+
+	if (!first_synth_freq)
+		return -EOPNOTSUPP;
+
+	/* No enabled outputs found; step ToD counter only using the
+	 * lowest-ID synth's period (empty output mask).
+	 */
+	if (!tod_stepped) {
+		step_cycles = div_s64(delta * first_synth_freq, NSEC_PER_SEC);
+		return zl3073x_chan_phase_step(zldev, zldpll->id, 0,
+					       step_cycles, true);
+	}
+
+	return 0;
 }
 
 /**
- * zl3073x_dpll_free - free DPLL device
- * @zldpll: pointer to zl3073x_dpll structure
+ * zl3073x_dpll_ptp_adjtime - adjust PTP clock time
+ * @info: PTP clock info
+ * @delta: time adjustment in nanoseconds
  *
- * Deallocates given DPLL device previously allocated by @zl3073x_dpll_alloc.
+ * For large deltas (>= 1 second), the seconds part is adjusted via ToD
+ * read-modify-write at 1 Hz boundaries and the sub-second remainder via
+ * output phase step. For sub-second deltas, uses phase step directly.
+ * Falls back to full ToD read-modify-write if phase step is unavailable.
+ *
+ * Return: 0 on success, <0 on error
  */
-void
-zl3073x_dpll_free(struct zl3073x_dpll *zldpll)
+static int zl3073x_dpll_ptp_adjtime(struct ptp_clock_info *info, s64 delta)
 {
-	WARN(zldpll->dpll_dev, "DPLL device is still registered\n");
+	struct zl3073x_dpll *zldpll = container_of(info, struct zl3073x_dpll,
+						   ptp_info);
+	struct zl3073x_dev *zldev = zldpll->dev;
+	bool sec_adjusted = false;
+	struct timespec64 ts;
+	int rc;
 
-	mutex_destroy(&zldpll->lock);
-	kfree(zldpll);
+	if (!delta)
+		return 0;
+
+	guard(mutex)(&zldpll->lock);
+
+	/* Split off seconds via ToD read-modify-write so the sub-second
+	 * remainder can be applied through the output-coherent phase step.
+	 */
+	if (abs(delta) >= NSEC_PER_SEC) {
+		s32 remainder;
+
+		ts.tv_sec = div_s64_rem(delta, NSEC_PER_SEC, &remainder);
+		ts.tv_nsec = 0;
+		delta = remainder;
+
+		rc = zl3073x_chan_tod_adjust(zldev, zldpll->id, ts);
+		if (rc)
+			return rc;
+
+		sec_adjusted = true;
+
+		/* No sub-second remainder, done */
+		if (!delta)
+			return 0;
+	}
+
+	rc = zl3073x_dpll_ptp_adjtime_phase_step(zldpll, delta);
+	if (!rc)
+		return 0;
+
+	/* Phase step failed or unavailable, fall back to ToD adjust */
+	rc = zl3073x_chan_tod_adjust(zldev, zldpll->id,
+				     ns_to_timespec64(delta));
+
+	/* In the unlikely event that both phase step and fallback ToD adjust
+	 * fail after seconds were already committed, return success to prevent
+	 * the PTP servo from retrying the full delta and applying seconds
+	 * again. The sub-second residual will self-correct in the next servo
+	 * cycle.
+	 */
+	if (rc && sec_adjusted) {
+		dev_warn(zldev->dev,
+			 "Sub-second adjustment failed after seconds applied\n");
+		return 0;
+	}
+
+	return rc;
+}
+
+/**
+ * zl3073x_dpll_ptp_adjfine - adjust PTP clock frequency
+ * @info: PTP clock info
+ * @scaled_ppm: frequency adjustment in scaled ppm (ppm * 2^16)
+ *
+ * Writes the delta frequency offset register.
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int
+zl3073x_dpll_ptp_adjfine(struct ptp_clock_info *info, long scaled_ppm)
+{
+	struct zl3073x_dpll *zldpll = container_of(info, struct zl3073x_dpll,
+						   ptp_info);
+	const struct zl3073x_chan *chan;
+	s64 offset;
+
+	/* Convert scaled_ppm to df_offset in 2^-48 steps:
+	 *   df_offset = -(scaled_ppm * 2^32) / 10^6
+	 *
+	 * Simplify to avoid overflow:
+	 *   df_offset = -(scaled_ppm * 2^26) / 5^6
+	 *   df_offset = -(scaled_ppm * 67108864) / 15625
+	 */
+	offset = -div_s64((s64)scaled_ppm * 67108864LL, 15625);
+
+	guard(mutex)(&zldpll->lock);
+
+	chan = zl3073x_chan_state_get(zldpll->dev, zldpll->id);
+	if (offset == chan->df_offset)
+		return 0;
+
+	return zl3073x_chan_df_offset_set(zldpll->dev, zldpll->id, offset);
+}
+
+/**
+ * zl3073x_dpll_ptp_perout_find_pin - find pin by perout channel index
+ * @zldpll: DPLL channel
+ * @idx: perout channel index to find
+ *
+ * Return: pointer to the pin, or NULL if not found
+ */
+static struct zl3073x_dpll_pin *
+zl3073x_dpll_ptp_perout_find_pin(struct zl3073x_dpll *zldpll, int idx)
+{
+	struct zl3073x_dpll_pin *pin;
+
+	list_for_each_entry(pin, &zldpll->pins, list) {
+		if (pin->perout_idx == idx)
+			return pin;
+	}
+
+	return NULL;
+}
+
+/**
+ * zl3073x_dpll_ptp_enable - enable/disable PTP clock functions
+ * @info: PTP clock info
+ * @rq: the requested clock function and parameters
+ * @on: true to enable, false to disable
+ *
+ * Handles PTP_CLK_REQ_PEROUT requests. Only 1PPS (period = 1s) is supported.
+ * On enable, configures the output divider for 1 Hz. On disable, does nothing
+ * as the signal is not disabled.
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int zl3073x_dpll_ptp_enable(struct ptp_clock_info *info,
+				   struct ptp_clock_request *rq, int on)
+{
+	struct zl3073x_dpll *zldpll = container_of(info, struct zl3073x_dpll,
+						   ptp_info);
+	struct zl3073x_dpll_pin *pin;
+	unsigned int idx;
+	int rc;
+
+	if (rq->type != PTP_CLK_REQ_PEROUT)
+		return -EOPNOTSUPP;
+
+	idx = rq->perout.index;
+	if (idx >= info->n_per_out)
+		return -EINVAL;
+
+	/* Toggling output pins can produce runt pulses, so disable
+	 * is a no-op.
+	 */
+	if (!on)
+		return 0;
+
+	/* Only accept exactly 1PPS (period.sec == 1, nsec == 0) */
+	if (rq->perout.period.sec != 1 || rq->perout.period.nsec != 0)
+		return -EINVAL;
+
+	mutex_lock(&zldpll->lock);
+
+	pin = zl3073x_dpll_ptp_perout_find_pin(zldpll, idx);
+	if (!pin) {
+		mutex_unlock(&zldpll->lock);
+		return -EINVAL;
+	}
+
+	/* Already at 1 Hz, nothing to do */
+	if (zl3073x_dev_output_pin_freq_get(zldpll->dev, pin->id) == 1) {
+		mutex_unlock(&zldpll->lock);
+		return 0;
+	}
+
+	rc = __zl3073x_dpll_output_pin_frequency_set(zldpll, pin, 1);
+
+	mutex_unlock(&zldpll->lock);
+
+	if (!rc)
+		dpll_pin_change_ntf(pin->dpll_pin);
+
+	return rc;
+}
+
+static const struct ptp_clock_info zl3073x_dpll_ptp_clock_info = {
+	.owner		= THIS_MODULE,
+	.max_adj	= ZL3073X_DPLL_PTP_MAX_ADJ,
+	.gettimex64	= zl3073x_dpll_ptp_gettimex64,
+	.settime64	= zl3073x_dpll_ptp_settime64,
+	.adjtime	= zl3073x_dpll_ptp_adjtime,
+	.adjfine	= zl3073x_dpll_ptp_adjfine,
+	.enable		= zl3073x_dpll_ptp_enable,
+};
+
+/**
+ * zl3073x_dpll_ptp_register - register PTP clock for a DPLL channel
+ * @zldpll: DPLL channel to register PTP clock for
+ *
+ * PTP clock is only registered when the channel is in NCO mode.
+ * If the channel is not in NCO mode, this is a no-op.
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int zl3073x_dpll_ptp_register(struct zl3073x_dpll *zldpll)
+{
+	struct zl3073x_dev *zldev = zldpll->dev;
+	const struct zl3073x_chan *chan;
+	struct ptp_clock *ptp_clock;
+
+	chan = zl3073x_chan_state_get(zldev, zldpll->id);
+	if (!zl3073x_chan_mode_is_nco(chan))
+		return 0;
+
+	snprintf(zldpll->ptp_info.name, sizeof(zldpll->ptp_info.name),
+		 "zl3073x-dpll%u", zldpll->id);
+
+	ptp_clock = ptp_clock_register(&zldpll->ptp_info, zldev->dev);
+	if (IS_ERR(ptp_clock)) {
+		dev_err(zldev->dev, "Failed to register PTP clock for DPLL%u\n",
+			zldpll->id);
+		return PTR_ERR(ptp_clock);
+	}
+
+	zldpll->ptp_clock = ptp_clock;
+
+	return 0;
+}
+
+/**
+ * zl3073x_dpll_ptp_unregister - unregister PTP clock for a DPLL channel
+ * @zldpll: DPLL channel to unregister PTP clock for
+ */
+static void zl3073x_dpll_ptp_unregister(struct zl3073x_dpll *zldpll)
+{
+	if (!IS_ERR_OR_NULL(zldpll->ptp_clock)) {
+		ptp_clock_unregister(zldpll->ptp_clock);
+		zldpll->ptp_clock = NULL;
+	}
 }
 
 /**
@@ -2403,6 +2809,48 @@ zl3073x_dpll_ref_sync_pairs_register(struct zl3073x_dpll *zldpll)
 	return 0;
 }
 
+/**
+ * zl3073x_dpll_alloc - allocate DPLL device
+ * @zldev: pointer to zl3073x device
+ * @ch: DPLL channel number
+ *
+ * Allocates DPLL device structure for given DPLL channel.
+ *
+ * Return: pointer to DPLL device on success, error pointer on error
+ */
+struct zl3073x_dpll *
+zl3073x_dpll_alloc(struct zl3073x_dev *zldev, u8 ch)
+{
+	struct zl3073x_dpll *zldpll;
+
+	zldpll = kzalloc_obj(*zldpll);
+	if (!zldpll)
+		return ERR_PTR(-ENOMEM);
+
+	zldpll->dev = zldev;
+	zldpll->id = ch;
+	zldpll->ptp_info = zl3073x_dpll_ptp_clock_info;
+	mutex_init(&zldpll->lock);
+	INIT_LIST_HEAD(&zldpll->pins);
+
+	return zldpll;
+}
+
+/**
+ * zl3073x_dpll_free - free DPLL device
+ * @zldpll: pointer to zl3073x_dpll structure
+ *
+ * Deallocates given DPLL device previously allocated by @zl3073x_dpll_alloc.
+ */
+void
+zl3073x_dpll_free(struct zl3073x_dpll *zldpll)
+{
+	WARN(zldpll->dpll_dev, "DPLL device is still registered\n");
+
+	mutex_destroy(&zldpll->lock);
+	kfree(zldpll);
+}
+
 /**
  * zl3073x_dpll_register - register DPLL device and all its pins
  * @zldpll: pointer to zl3073x_dpll structure
@@ -2433,6 +2881,13 @@ zl3073x_dpll_register(struct zl3073x_dpll *zldpll)
 		return rc;
 	}
 
+	rc = zl3073x_dpll_ptp_register(zldpll);
+	if (rc) {
+		zl3073x_dpll_pins_unregister(zldpll);
+		zl3073x_dpll_device_unregister(zldpll);
+		return rc;
+	}
+
 	return 0;
 }
 
@@ -2446,7 +2901,7 @@ zl3073x_dpll_register(struct zl3073x_dpll *zldpll)
 void
 zl3073x_dpll_unregister(struct zl3073x_dpll *zldpll)
 {
-	/* Unregister all pins and dpll */
+	zl3073x_dpll_ptp_unregister(zldpll);
 	zl3073x_dpll_pins_unregister(zldpll);
 	zl3073x_dpll_device_unregister(zldpll);
 }
diff --git a/drivers/dpll/zl3073x/dpll.h b/drivers/dpll/zl3073x/dpll.h
index faebc402ba1b7..9b5f72c33849c 100644
--- a/drivers/dpll/zl3073x/dpll.h
+++ b/drivers/dpll/zl3073x/dpll.h
@@ -5,6 +5,8 @@
 
 #include <linux/dpll.h>
 #include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/ptp_clock_kernel.h>
 
 #include "core.h"
 
@@ -22,6 +24,8 @@
  * @type: DPLL type (PPS or EEC)
  * @lock_status: last saved DPLL lock status
  * @pins: list of pins
+ * @ptp_info: PTP clock info
+ * @ptp_clock: registered PTP clock (or NULL)
  */
 struct zl3073x_dpll {
 	struct list_head		list;
@@ -36,6 +40,8 @@ struct zl3073x_dpll {
 	enum dpll_type			type;
 	enum dpll_lock_status		lock_status;
 	struct list_head		pins;
+	struct ptp_clock_info		ptp_info;
+	struct ptp_clock		*ptp_clock;
 };
 
 struct zl3073x_dpll *zl3073x_dpll_alloc(struct zl3073x_dev *zldev, u8 ch);
-- 
2.53.0

[PATCH net-next 3/4] dpll: zl3073x: add channel TIE write operation

[Ivan Vecera]

Add TIE phase adjustment operation zl3073x_chan_tie_write() that
converts nanoseconds to TIE units (0.01 ps) and writes TIE data
to the specified DPLL channel. A tie_lock mutex serializes TIE
operations.

Add convenience helper zl3073x_chan_mode_supports_tie() to chan.h.

Tested-by: Chris du Quesnay <Chris.duQuesnay@microchip.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
 drivers/dpll/zl3073x/chan.c | 40 +++++++++++++++++++++++++++++++++++++
 drivers/dpll/zl3073x/chan.h | 17 ++++++++++++++++
 drivers/dpll/zl3073x/core.c |  4 ++++
 drivers/dpll/zl3073x/core.h |  3 +++
 drivers/dpll/zl3073x/regs.h | 12 +++++++++++
 5 files changed, 76 insertions(+)

diff --git a/drivers/dpll/zl3073x/chan.c b/drivers/dpll/zl3073x/chan.c
index 8360444559d09..53032e782fd4a 100644
--- a/drivers/dpll/zl3073x/chan.c
+++ b/drivers/dpll/zl3073x/chan.c
@@ -450,6 +450,46 @@ int zl3073x_chan_df_offset_set(struct zl3073x_dev *zldev, u8 ch, s64 offset)
 	return rc;
 }
 
+/**
+ * zl3073x_chan_tie_write - adjust DPLL phase using TIE write
+ * @zldev: pointer to zl3073x device
+ * @ch: DPLL channel index
+ * @delta_ns: phase adjustment in nanoseconds (must be within +-1s)
+ *
+ * Converts nanoseconds to TIE units (0.01 ps) and writes TIE data
+ * to the specified channel.
+ *
+ * Return: 0 on success, <0 on error
+ */
+int zl3073x_chan_tie_write(struct zl3073x_dev *zldev, u8 ch, s64 delta_ns)
+{
+	s64 tie_data;
+	int rc;
+
+	guard(mutex)(&zldev->tie_lock);
+
+	/* Wait for any previous TIE operation to complete */
+	rc = zl3073x_poll_zero_u8(zldev, ZL_REG_DPLL_TIE_CTRL,
+				  ZL_DPLL_TIE_CTRL_OP,
+				  ZL_POLL_TIE_WR_TIMEOUT_US);
+	if (rc)
+		return rc;
+
+	/* Convert ns to TIE units (0.01 ps = 10^-14 s) */
+	tie_data = delta_ns * 100000LL;
+
+	rc = zl3073x_write_u48(zldev, ZL_REG_DPLL_TIE_DATA(ch), tie_data);
+	if (rc)
+		return rc;
+
+	rc = zl3073x_write_u8(zldev, ZL_REG_DPLL_TIE_CTRL_MASK, BIT(ch));
+	if (rc)
+		return rc;
+
+	return zl3073x_write_u8(zldev, ZL_REG_DPLL_TIE_CTRL,
+				ZL_DPLL_TIE_CTRL_OP_WR);
+}
+
 /**
  * zl3073x_chan_phase_step - execute one output phase step operation
  * @zldev: pointer to zl3073x device
diff --git a/drivers/dpll/zl3073x/chan.h b/drivers/dpll/zl3073x/chan.h
index 56a3db012cf50..9dc5a3f1991f1 100644
--- a/drivers/dpll/zl3073x/chan.h
+++ b/drivers/dpll/zl3073x/chan.h
@@ -60,6 +60,8 @@ int zl3073x_chan_phase_step(struct zl3073x_dev *zldev, u8 ch,
 
 int zl3073x_chan_df_offset_set(struct zl3073x_dev *zldev, u8 ch, s64 offset);
 
+int zl3073x_chan_tie_write(struct zl3073x_dev *zldev, u8 ch, s64 delta_ns);
+
 /**
  * zl3073x_chan_df_offset_get - get cached df_offset vs tracked reference
  * @chan: pointer to channel state
@@ -218,6 +220,21 @@ static inline bool zl3073x_chan_mode_is_reflock(const struct zl3073x_chan *chan)
 	return zl3073x_chan_mode_get(chan) == ZL_DPLL_MODE_REFSEL_MODE_REFLOCK;
 }
 
+/**
+ * zl3073x_chan_mode_supports_tie - check if channel mode supports TIE write
+ * @chan: pointer to channel state
+ *
+ * TIE write is supported in AUTO and REFLOCK modes regardless of lock state.
+ *
+ * Return: true if TIE write is supported, false otherwise
+ */
+static inline bool
+zl3073x_chan_mode_supports_tie(const struct zl3073x_chan *chan)
+{
+	return zl3073x_chan_mode_is_auto(chan) ||
+		zl3073x_chan_mode_is_reflock(chan);
+}
+
 /**
  * zl3073x_chan_is_ho_ready - check if holdover is ready
  * @chan: pointer to channel state
diff --git a/drivers/dpll/zl3073x/core.c b/drivers/dpll/zl3073x/core.c
index 958b722d7a38d..b2f9fc97fd1b6 100644
--- a/drivers/dpll/zl3073x/core.c
+++ b/drivers/dpll/zl3073x/core.c
@@ -1037,6 +1037,10 @@ int zl3073x_dev_probe(struct zl3073x_dev *zldev)
 		return dev_err_probe(zldev->dev, rc,
 				     "Failed to initialize mutex\n");
 	rc = devm_mutex_init(zldev->dev, &zldev->phase_step_lock);
+	if (rc)
+		return dev_err_probe(zldev->dev, rc,
+				     "Failed to initialize mutex\n");
+	rc = devm_mutex_init(zldev->dev, &zldev->tie_lock);
 	if (rc)
 		return dev_err_probe(zldev->dev, rc,
 				     "Failed to initialize mutex\n");
diff --git a/drivers/dpll/zl3073x/core.h b/drivers/dpll/zl3073x/core.h
index bd60104ee567a..2dc836d0c8f6b 100644
--- a/drivers/dpll/zl3073x/core.h
+++ b/drivers/dpll/zl3073x/core.h
@@ -27,6 +27,7 @@ struct zl3073x_dpll;
 #define ZL_POLL_MB_TIMEOUT_US		(30 * USEC_PER_MSEC)
 #define ZL_POLL_PHASE_ERR_TIMEOUT_US	(50 * USEC_PER_MSEC)
 #define ZL_POLL_PHASE_STEP_TIMEOUT_US	(3000 * USEC_PER_MSEC)
+#define ZL_POLL_TIE_WR_TIMEOUT_US	(1000 * USEC_PER_MSEC)
 #define ZL_POLL_TOD_RD_TIMEOUT_US	(30 * USEC_PER_MSEC)
 #define ZL_POLL_TOD_WR_TIMEOUT_US	(1000 * USEC_PER_MSEC)
 
@@ -58,6 +59,7 @@ struct zl3073x_chip_info {
  * @regmap: regmap to access device registers
  * @info: detected chip info
  * @multiop_lock: to serialize multiple register operations
+ * @tie_lock: to serialize TIE write operations
  * @phase_step_lock: to serialize output phase step operations
  * @ref: array of input references' invariants
  * @out: array of outs' invariants
@@ -75,6 +77,7 @@ struct zl3073x_dev {
 	struct regmap			*regmap;
 	const struct zl3073x_chip_info	*info;
 	struct mutex			multiop_lock;
+	struct mutex			tie_lock;
 	struct mutex			phase_step_lock;
 
 	/* Invariants */
diff --git a/drivers/dpll/zl3073x/regs.h b/drivers/dpll/zl3073x/regs.h
index 9b8e06fddaa6c..447757e99845d 100644
--- a/drivers/dpll/zl3073x/regs.h
+++ b/drivers/dpll/zl3073x/regs.h
@@ -179,6 +179,12 @@
 #define ZL_DPLL_DF_READ_CMD			GENMASK(2, 0)
 #define ZL_DPLL_DF_READ_CMD_ACC_I		4
 
+#define ZL_REG_DPLL_TIE_CTRL			ZL_REG(5, 0x30, 1)
+#define ZL_DPLL_TIE_CTRL_OP			GENMASK(2, 0)
+#define ZL_DPLL_TIE_CTRL_OP_WR			4
+
+#define ZL_REG_DPLL_TIE_CTRL_MASK		ZL_REG(5, 0x31, 1)
+
 #define ZL_REG_DPLL_TOD_CTRL(_idx)					\
 	ZL_REG_IDX(_idx, 5, 0x38, 1, 8, 1)
 #define ZL_DPLL_TOD_CTRL_SEM			BIT(4)
@@ -213,6 +219,12 @@
 	((_idx) < 4 ? ZL_REG_DPLL_DF_OFFSET_03(_idx) : ZL_REG_DPLL_DF_OFFSET_4)
 #define ZL_DPLL_DF_OFFSET_UNKNOWN	S64_MIN
 
+#define ZL_REG_DPLL_TIE_DATA_03(_idx)					\
+	ZL_REG_IDX(_idx, 6, 0x0C, 6, 4, 0x20)
+#define ZL_REG_DPLL_TIE_DATA_4			ZL_REG(7, 0x0C, 6)
+#define ZL_REG_DPLL_TIE_DATA(_idx)					\
+	((_idx) < 4 ? ZL_REG_DPLL_TIE_DATA_03(_idx) : ZL_REG_DPLL_TIE_DATA_4)
+
 #define ZL_REG_DPLL_TOD_SEC_03(_idx)					\
 	ZL_REG_IDX(_idx, 6, 0x12, 6, 4, 0x20)
 #define ZL_REG_DPLL_TOD_SEC_4			ZL_REG(7, 0x12, 6)
-- 
2.53.0

[PATCH net-next 4/4] dpll: zl3073x: add PTP clock adjphase and TIE support

[Ivan Vecera]

Add adjphase and getmaxphase PTP callbacks using TIE write for
sub-picosecond phase adjustment in AUTO and REFLOCK modes.

Extend the adjtime callback to handle non-NCO modes: in AUTO/REFLOCK
modes the sub-second remainder is applied via TIE write instead of
phase step. In modes that support neither, the full adjustment falls
back to ToD read-modify-write.

Remove the NCO-only gate from PTP clock registration since the PTP
clock now provides useful operations in all modes. Add a mode check
to adjfine so it returns -EOPNOTSUPP when not in NCO mode.

Tested-by: Chris du Quesnay <Chris.duQuesnay@microchip.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
 drivers/dpll/zl3073x/dpll.c | 102 +++++++++++++++++++++++++++---------
 1 file changed, 78 insertions(+), 24 deletions(-)

diff --git a/drivers/dpll/zl3073x/dpll.c b/drivers/dpll/zl3073x/dpll.c
index 86770dea3d652..74001e6d4a32f 100644
--- a/drivers/dpll/zl3073x/dpll.c
+++ b/drivers/dpll/zl3073x/dpll.c
@@ -2489,10 +2489,13 @@ static int zl3073x_dpll_ptp_adjtime_phase_step(struct zl3073x_dpll *zldpll,
  * @info: PTP clock info
  * @delta: time adjustment in nanoseconds
  *
- * For large deltas (>= 1 second), the seconds part is adjusted via ToD
- * read-modify-write at 1 Hz boundaries and the sub-second remainder via
- * output phase step. For sub-second deltas, uses phase step directly.
- * Falls back to full ToD read-modify-write if phase step is unavailable.
+ * In NCO mode, large deltas (>= 1 second) are split into a ToD
+ * read-modify-write for the seconds part and an output phase step for
+ * the sub-second remainder. Sub-second deltas use phase step directly,
+ * falling back to ToD read-modify-write if phase step is unavailable.
+ * In AUTO/REFLOCK modes, large deltas are split into ToD
+ * read-modify-write for seconds and TIE write for the sub-second
+ * remainder. Sub-second deltas use TIE write directly.
  *
  * Return: 0 on success, <0 on error
  */
@@ -2501,6 +2504,7 @@ static int zl3073x_dpll_ptp_adjtime(struct ptp_clock_info *info, s64 delta)
 	struct zl3073x_dpll *zldpll = container_of(info, struct zl3073x_dpll,
 						   ptp_info);
 	struct zl3073x_dev *zldev = zldpll->dev;
+	const struct zl3073x_chan *chan;
 	bool sec_adjusted = false;
 	struct timespec64 ts;
 	int rc;
@@ -2510,8 +2514,16 @@ static int zl3073x_dpll_ptp_adjtime(struct ptp_clock_info *info, s64 delta)
 
 	guard(mutex)(&zldpll->lock);
 
+	/* Modes without phase step or TIE use plain ToD adjust */
+	chan = zl3073x_chan_state_get(zldev, zldpll->id);
+	if (!zl3073x_chan_mode_is_nco(chan) &&
+	    !zl3073x_chan_mode_supports_tie(chan))
+		return zl3073x_chan_tod_adjust(zldev, zldpll->id,
+					       ns_to_timespec64(delta));
+
 	/* Split off seconds via ToD read-modify-write so the sub-second
-	 * remainder can be applied through the output-coherent phase step.
+	 * remainder can be applied through the output-coherent mechanism
+	 * (phase step or TIE write).
 	 */
 	if (abs(delta) >= NSEC_PER_SEC) {
 		s32 remainder;
@@ -2531,19 +2543,26 @@ static int zl3073x_dpll_ptp_adjtime(struct ptp_clock_info *info, s64 delta)
 			return 0;
 	}
 
-	rc = zl3073x_dpll_ptp_adjtime_phase_step(zldpll, delta);
-	if (!rc)
-		return 0;
+	/* Apply sub-second delta via phase step (NCO) or TIE write */
+	if (zl3073x_chan_mode_is_nco(chan)) {
+		rc = zl3073x_dpll_ptp_adjtime_phase_step(zldpll, delta);
+		if (!rc)
+			return 0;
+	} else {
+		rc = zl3073x_chan_tie_write(zldev, zldpll->id, delta);
+		if (!rc)
+			return 0;
+	}
 
-	/* Phase step failed or unavailable, fall back to ToD adjust */
+	/* Phase step or TIE write failed, fall back to ToD adjust */
 	rc = zl3073x_chan_tod_adjust(zldev, zldpll->id,
 				     ns_to_timespec64(delta));
 
-	/* In the unlikely event that both phase step and fallback ToD adjust
-	 * fail after seconds were already committed, return success to prevent
-	 * the PTP servo from retrying the full delta and applying seconds
-	 * again. The sub-second residual will self-correct in the next servo
-	 * cycle.
+	/* In the unlikely event that both phase step/TIE write and fallback
+	 * ToD adjust fail after seconds were already committed, return
+	 * success to prevent the PTP servo from retrying the full delta and
+	 * applying seconds again. The sub-second residual will self-correct
+	 * in the next servo cycle.
 	 */
 	if (rc && sec_adjusted) {
 		dev_warn(zldev->dev,
@@ -2559,9 +2578,9 @@ static int zl3073x_dpll_ptp_adjtime(struct ptp_clock_info *info, s64 delta)
  * @info: PTP clock info
  * @scaled_ppm: frequency adjustment in scaled ppm (ppm * 2^16)
  *
- * Writes the delta frequency offset register.
+ * Only supported in NCO mode. Writes the delta frequency offset register.
  *
- * Return: 0 on success, <0 on error
+ * Return: 0 on success, -EOPNOTSUPP if not in NCO mode, <0 on error
  */
 static int
 zl3073x_dpll_ptp_adjfine(struct ptp_clock_info *info, long scaled_ppm)
@@ -2583,12 +2602,53 @@ zl3073x_dpll_ptp_adjfine(struct ptp_clock_info *info, long scaled_ppm)
 	guard(mutex)(&zldpll->lock);
 
 	chan = zl3073x_chan_state_get(zldpll->dev, zldpll->id);
+	if (!zl3073x_chan_mode_is_nco(chan))
+		return scaled_ppm ? -EOPNOTSUPP : 0;
 	if (offset == chan->df_offset)
 		return 0;
 
 	return zl3073x_chan_df_offset_set(zldpll->dev, zldpll->id, offset);
 }
 
+/**
+ * zl3073x_dpll_ptp_adjphase - adjust PTP clock phase
+ * @info: PTP clock info
+ * @delta: phase adjustment in nanoseconds
+ *
+ * Only supported in AUTO and REFLOCK modes. Uses TIE write for
+ * nanosecond resolution phase adjustment.
+ *
+ * Return: 0 on success, -EOPNOTSUPP if mode doesn't support TIE, <0 on error
+ */
+static int zl3073x_dpll_ptp_adjphase(struct ptp_clock_info *info, s32 delta)
+{
+	struct zl3073x_dpll *zldpll = container_of(info, struct zl3073x_dpll,
+						   ptp_info);
+	struct zl3073x_dev *zldev = zldpll->dev;
+	const struct zl3073x_chan *chan;
+
+	if (!delta)
+		return 0;
+
+	guard(mutex)(&zldpll->lock);
+
+	chan = zl3073x_chan_state_get(zldev, zldpll->id);
+
+	if (!zl3073x_chan_mode_supports_tie(chan))
+		return -EOPNOTSUPP;
+
+	return zl3073x_chan_tie_write(zldev, zldpll->id, delta);
+}
+
+static s32
+zl3073x_dpll_ptp_getmaxphase(struct ptp_clock_info *info __always_unused)
+{
+	/* HW limits TIE write to +-1 second. Return the constant HW
+	 * limit and let adjphase handle mode-specific checks.
+	 */
+	return NSEC_PER_SEC - 1;
+}
+
 /**
  * zl3073x_dpll_ptp_perout_find_pin - find pin by perout channel index
  * @zldpll: DPLL channel
@@ -2678,6 +2738,8 @@ static const struct ptp_clock_info zl3073x_dpll_ptp_clock_info = {
 	.settime64	= zl3073x_dpll_ptp_settime64,
 	.adjtime	= zl3073x_dpll_ptp_adjtime,
 	.adjfine	= zl3073x_dpll_ptp_adjfine,
+	.adjphase	= zl3073x_dpll_ptp_adjphase,
+	.getmaxphase	= zl3073x_dpll_ptp_getmaxphase,
 	.enable		= zl3073x_dpll_ptp_enable,
 };
 
@@ -2685,21 +2747,13 @@ static const struct ptp_clock_info zl3073x_dpll_ptp_clock_info = {
  * zl3073x_dpll_ptp_register - register PTP clock for a DPLL channel
  * @zldpll: DPLL channel to register PTP clock for
  *
- * PTP clock is only registered when the channel is in NCO mode.
- * If the channel is not in NCO mode, this is a no-op.
- *
  * Return: 0 on success, <0 on error
  */
 static int zl3073x_dpll_ptp_register(struct zl3073x_dpll *zldpll)
 {
 	struct zl3073x_dev *zldev = zldpll->dev;
-	const struct zl3073x_chan *chan;
 	struct ptp_clock *ptp_clock;
 
-	chan = zl3073x_chan_state_get(zldev, zldpll->id);
-	if (!zl3073x_chan_mode_is_nco(chan))
-		return 0;
-
 	snprintf(zldpll->ptp_info.name, sizeof(zldpll->ptp_info.name),
 		 "zl3073x-dpll%u", zldpll->id);
 
-- 
2.53.0

Re: [PATCH net-next 1/4] dpll: zl3073x: add channel ToD and phase step operations

[Vadim Fedorenko]

On 08/07/2026 18:05, Ivan Vecera wrote:
> Add low-level DPLL channel operations for ToD read/write/adjust,
> delta frequency offset write and output phase step. ToD operations
> use a wait-before-write pattern to avoid blocking after each
> operation. tod_adjust additionally waits for completion since callers
> may follow with phase step operations.
> 
> The tod_ready_wait helper selects the poll timeout based on the
> current ToD command - write operations use a longer timeout (1000 ms)
> than reads (30 ms).
> 
> The ToD read captures system timestamps (ptp_system_timestamp) around
> the HW command and completion poll to support cross-timestamping.
> 
> Add output step-time mask invariant to zl3073x_chan and
> zl3073x_chan_is_out_stepped() helper to check if an output
> participates in step-time operations.
> 

[...]

> +/**
> + * zl3073x_chan_tod_read - read ToD registers after issuing a command
> + * @zldev: pointer to zl3073x device
> + * @ch: DPLL channel index
> + * @next_hz: if true, read predicted ToD at next 1 Hz; otherwise read current
> + * @ts: timespec to store the result
> + * @sts: optional system timestamp pair for cross-timestamping
> + *
> + * Context: Caller must serialize all zl3073x_chan_tod_* calls externally.
> + * Return: 0 on success, <0 on error
> + */
> +int zl3073x_chan_tod_read(struct zl3073x_dev *zldev, u8 ch,
> +			  bool next_hz, struct timespec64 *ts,
> +			  struct ptp_system_timestamp *sts)
> +{
> +	u32 nsec;
> +	u64 sec;
> +	u8 cmd;
> +	int rc;
> +
> +	if (next_hz)
> +		cmd = ZL_DPLL_TOD_CTRL_CMD_RD_NEXT_1HZ;
> +	else
> +		cmd = ZL_DPLL_TOD_CTRL_CMD_RD_CURRENT;
> +
> +	/* Wait for any previous ToD operation to complete */
> +	rc = zl3073x_chan_tod_ready_wait(zldev, ch);
> +	if (rc)
> +		return rc;
> +
> +	ptp_read_system_prets(sts);
> +	rc = zl3073x_chan_tod_ctrl(zldev, ch, cmd);
> +	if (rc)
> +		return rc;
> +
> +	rc = zl3073x_chan_tod_ready_wait(zldev, ch);
> +	if (rc)
> +		return rc;
> +	ptp_read_system_postts(sts);

AFAIU, this code means that the ToD value was somewhere between tod_ctrl
command and tod_ready read value 0 of the register. How does it work
with "predicted ToD at next 1 Hz"?

> +
> +	rc = zl3073x_read_u48(zldev, ZL_REG_DPLL_TOD_SEC(ch), &sec);
> +	if (rc)
> +		return rc;
> +
> +	/* HW nanoseconds are always in [0, NSEC_PER_SEC) range */
> +	rc = zl3073x_read_u32(zldev, ZL_REG_DPLL_TOD_NS(ch), &nsec);
> +	if (rc)
> +		return rc;
> +
> +	ts->tv_sec = sec;
> +	ts->tv_nsec = nsec;
> +
> +	return 0;
> +}
[...]

Re: [PATCH net-next 2/4] dpll: zl3073x: add PTP clock support

[Vadim Fedorenko]

On 08/07/2026 18:05, Ivan Vecera wrote:
> Add PTP clock support for the ZL3073x DPLL driver. A PTP clock device
> is registered for each DPLL channel that is in NCO mode, providing
> gettimex64, settime64, adjtime, adjfine and perout callbacks.

Here we come back to the discussion of NCO mode. Is DPLL channel
actually a pin (virtual or physical)? If it's not, then it means that
channel is exposed as independent DPLL device, that shouldn't affect
other devices, but AFAIU, it can in the current implementation. If it is
a pin, why do you check device's mode rather then pins?

And another question - what happens when channel changes its mode to
non-NCO? Do we have ptp device disappearing from the system?

Re: [PATCH net-next 1/4] dpll: zl3073x: add channel ToD and phase step operations

[Ivan Vecera]

On 7/10/26 2:56 PM, Vadim Fedorenko wrote:
> On 08/07/2026 18:05, Ivan Vecera wrote:
>> Add low-level DPLL channel operations for ToD read/write/adjust,
>> delta frequency offset write and output phase step. ToD operations
>> use a wait-before-write pattern to avoid blocking after each
>> operation. tod_adjust additionally waits for completion since callers
>> may follow with phase step operations.
>>
>> The tod_ready_wait helper selects the poll timeout based on the
>> current ToD command - write operations use a longer timeout (1000 ms)
>> than reads (30 ms).
>>
>> The ToD read captures system timestamps (ptp_system_timestamp) around
>> the HW command and completion poll to support cross-timestamping.
>>
>> Add output step-time mask invariant to zl3073x_chan and
>> zl3073x_chan_is_out_stepped() helper to check if an output
>> participates in step-time operations.
>>
> 
> [...]
> 
>> +/**
>> + * zl3073x_chan_tod_read - read ToD registers after issuing a command
>> + * @zldev: pointer to zl3073x device
>> + * @ch: DPLL channel index
>> + * @next_hz: if true, read predicted ToD at next 1 Hz; otherwise read 
>> current
>> + * @ts: timespec to store the result
>> + * @sts: optional system timestamp pair for cross-timestamping
>> + *
>> + * Context: Caller must serialize all zl3073x_chan_tod_* calls 
>> externally.
>> + * Return: 0 on success, <0 on error
>> + */
>> +int zl3073x_chan_tod_read(struct zl3073x_dev *zldev, u8 ch,
>> +              bool next_hz, struct timespec64 *ts,
>> +              struct ptp_system_timestamp *sts)
>> +{
>> +    u32 nsec;
>> +    u64 sec;
>> +    u8 cmd;
>> +    int rc;
>> +
>> +    if (next_hz)
>> +        cmd = ZL_DPLL_TOD_CTRL_CMD_RD_NEXT_1HZ;
>> +    else
>> +        cmd = ZL_DPLL_TOD_CTRL_CMD_RD_CURRENT;
>> +
>> +    /* Wait for any previous ToD operation to complete */
>> +    rc = zl3073x_chan_tod_ready_wait(zldev, ch);
>> +    if (rc)
>> +        return rc;
>> +
>> +    ptp_read_system_prets(sts);
>> +    rc = zl3073x_chan_tod_ctrl(zldev, ch, cmd);
>> +    if (rc)
>> +        return rc;
>> +
>> +    rc = zl3073x_chan_tod_ready_wait(zldev, ch);
>> +    if (rc)
>> +        return rc;
>> +    ptp_read_system_postts(sts);
> 
> AFAIU, this code means that the ToD value was somewhere between tod_ctrl
> command and tod_ready read value 0 of the register. How does it work
> with "predicted ToD at next 1 Hz"?

The ptp_system_timestamp is only used by the gettimex64 callback which
always calls tod_read with next_hz=false (current ToD). The next_hz=true
path is only used internally by tod_adjust() which passes sts=NULL.

So in practice, system timestamps are never captured around a predicted
ToD read. The function accepts both options through the same interface
for simplicity, but the sts parameter is only meaningful with
next_hz=false.

Thanks,
Ivan

Re: [PATCH net-next 2/4] dpll: zl3073x: add PTP clock support

[Ivan Vecera]

On 7/10/26 3:08 PM, Vadim Fedorenko wrote:
> On 08/07/2026 18:05, Ivan Vecera wrote:
>> Add PTP clock support for the ZL3073x DPLL driver. A PTP clock device
>> is registered for each DPLL channel that is in NCO mode, providing
>> gettimex64, settime64, adjtime, adjfine and perout callbacks.
> 
> Here we come back to the discussion of NCO mode. Is DPLL channel
> actually a pin (virtual or physical)? If it's not, then it means that
> channel is exposed as independent DPLL device, that shouldn't affect
> other devices, but AFAIU, it can in the current implementation. If it is
> a pin, why do you check device's mode rather then pins?
> 
> And another question - what happens when channel changes its mode to
> non-NCO? Do we have ptp device disappearing from the system?

Hi Vadim,

I understand your point. The PTP code was originally developed before
the NCO pin switching was implemented, when it made sense to split PTP
support into two patches - basic PTP for NCO-only channels (patch 2) and
then extending it to all modes via TIE write (patch 4).

Now that NCO mode can be entered and left dynamically via the NCO pin,
this split no longer makes sense. Having patch 2 register PTP only for
NCO-mode channels creates an awkward intermediate state where a dynamic
NCO switch would require dynamic PTP clock registration/unregistration.

I'll squash patches 1&3 and 2&4 in v2, so the PTP clock is always
registered regardless of the initial channel mode, with per-callback
mode checks.

Thanks,
Ivan