[PATCH net-next v4 0/2] dpll: zl3073x: add PTP clock support

[PATCH net-next v4 0/2] dpll: zl3073x: add PTP clock support

[Ivan Vecera]

Add PTP hardware clock support to the zl3073x DPLL driver.

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

Patch 2 registers a PTP clock device for each DPLL channel with
gettimex64, settime64, adjtime, adjfine, adjphase and getmaxphase
callbacks. Callback availability adapts to the current channel
state - adjfine requires NCO pin connected, adjphase uses TIE write
when tracking a reference, and adjtime selects the appropriate
mechanism automatically. Periodic output support will be added in a
follow-up series.

Link: https://lore.kernel.org/netdev/20260730132150.371376-1-ivecera@redhat.com/
Link: https://lore.kernel.org/netdev/20260713103739.1553284-1-ivecera@redhat.com/
Link: https://lore.kernel.org/netdev/20260708170527.916035-1-ivecera@redhat.com/

Changes:
v4:
  - Move out_step_time_mask to struct zl3073x_dev (device-global)
  - Fix tod_adjust rollover guard for tick-crossing case
  - Drop trailing tod_ready_wait from tod_adjust
  - Fix TOD_CTRL register item count
  - Move phase step registers into existing page 9 section in regs.h
  - Align ToD command define values
  - Update kernel-doc for chan_state_fetch
  - Drop perout support (will rework as follow-up)
  - Replace abs(delta) with explicit range check to avoid S64_MIN UB
  - Add locking context doc to zl3073x_chan_df_offset_set
  - Export zl3073x_chan_tod_ready_wait and wait for ToD completion in
    adjtime before phase step/TIE write to prevent WR_NEXT_1HZ from
    overwriting the sub-second adjustment
v3:
  - Use PTP_1588_CLOCK instead of PTP_1588_CLOCK_OPTIONAL (Jakub)
  - Factor out output pin frequency helper to a separate commit (Jakub)
  - Remove spurious #include <linux/mutex.h> from dpll.h (Jakub)
v2:
  - Squash low-level ops patches (1+3) into patch 1.
  - Squash PTP callback patches (2+4) into patch 2, register PTP
    clock regardless of initial channel state.

Ivan Vecera (2):
  dpll: zl3073x: add channel ToD, phase step and TIE operations
  dpll: zl3073x: add PTP clock support

 drivers/dpll/zl3073x/Kconfig |   6 +-
 drivers/dpll/zl3073x/chan.c  | 310 ++++++++++++++++++++++++-
 drivers/dpll/zl3073x/chan.h  |  32 +++
 drivers/dpll/zl3073x/core.c  |  13 ++
 drivers/dpll/zl3073x/core.h  |  23 ++
 drivers/dpll/zl3073x/dpll.c  | 425 ++++++++++++++++++++++++++++++++---
 drivers/dpll/zl3073x/dpll.h  |   5 +
 drivers/dpll/zl3073x/regs.h  |  52 +++++
 8 files changed, 836 insertions(+), 30 deletions(-)


base-commit: a5c6ae8de11ef0c3aedbe5e123354aad87d0d925
-- 
2.54.0

[PATCH net-next v4 1/2] dpll: zl3073x: add channel ToD, phase step and TIE operations

[Ivan Vecera]

Add low-level DPLL channel operations for ToD read/write/adjust,
output phase step, delta frequency offset write and TIE (Time
Interval Error) write. These serve as building blocks for the PTP
clock callbacks added in the next patch.

ToD operations use a wait-before-write pattern to avoid blocking
after each operation.

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.

The TIE write operation provides sub-picosecond resolution phase
adjustment for modes where the DPLL is tracking a reference
(AUTO and REFLOCK).

Add output step-time mask to struct zl3073x_dev and
zl3073x_dev_out_is_stepped() helper to check if an output
participates in step-time operations.

Reviewed-by: Petr Oros <poros@redhat.com>
Tested-by: Chris du Quesnay <Chris.duQuesnay@microchip.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
 drivers/dpll/zl3073x/chan.c | 310 +++++++++++++++++++++++++++++++++++-
 drivers/dpll/zl3073x/chan.h |  32 ++++
 drivers/dpll/zl3073x/core.c |  13 ++
 drivers/dpll/zl3073x/core.h |  23 +++
 drivers/dpll/zl3073x/regs.h |  52 ++++++
 5 files changed, 428 insertions(+), 2 deletions(-)

diff --git a/drivers/dpll/zl3073x/chan.c b/drivers/dpll/zl3073x/chan.c
index 4ec2cf53dad468..79874a9fdb4962 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>
 
@@ -162,8 +163,8 @@ int zl3073x_chan_nco_mode_set(struct zl3073x_dev *zldev, u8 index)
  * @zldev: pointer to zl3073x_dev structure
  * @index: DPLL channel index to fetch state for
  *
- * Reads the mode_refsel register and reference priority registers for
- * the given DPLL channel and stores the raw values for later use.
+ * Reads the mode_refsel, status and reference priority registers for
+ * the given DPLL channel and stores the values for later use.
  *
  * Return: 0 on success, <0 on error
  */
@@ -234,6 +235,311 @@ 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
+ */
+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. If the tick crossed between the two reads,
+ * normalizes by the number of elapsed ticks. 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 the next rollover, wait it out. If the 1 Hz tick
+	 * crossed between the two reads, normalize by the elapsed ticks.
+	 */
+	diff = timespec64_sub(ts_next, ts_cur);
+	if (!diff.tv_sec && diff.tv_nsec < threshold_ns) {
+		fsleep((unsigned long)diff.tv_nsec / NSEC_PER_USEC + 1);
+		ts_next.tv_sec++;
+	} else if (diff.tv_sec < 0) {
+		ts_next.tv_sec -= diff.tv_sec;
+	}
+
+	/* Apply delta to the next-Hz ToD */
+	ts_next = timespec64_add(ts_next, delta);
+	if (!timespec64_valid(&ts_next))
+		return -EINVAL;
+
+	return zl3073x_chan_tod_write(zldev, ch, ts_next);
+}
+
+/**
+ * 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
+ *
+ * Context: Caller must hold the per-DPLL lock.
+ * 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_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;
+
+	if (WARN_ON(delta_ns <= -NSEC_PER_SEC || delta_ns >= NSEC_PER_SEC))
+		return -ERANGE;
+
+	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
+ * @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 dc9c6d95bdee75..99c3b7088f678f 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;
 
 /**
@@ -42,6 +44,21 @@ 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_ready_wait(struct zl3073x_dev *zldev, u8 ch);
+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);
+
+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
@@ -200,6 +217,21 @@ 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 7f5afaaae6342f..8a8c27a06ac9de 100644
--- a/drivers/dpll/zl3073x/core.c
+++ b/drivers/dpll/zl3073x/core.c
@@ -510,6 +510,11 @@ zl3073x_dev_state_fetch(struct zl3073x_dev *zldev)
 	int rc;
 	u8 i;
 
+	rc = zl3073x_read_u16(zldev, ZL_REG_OUTPUT_STEP_TIME_MASK,
+			      &zldev->out_step_time_mask);
+	if (rc)
+		return rc;
+
 	for (i = 0; i < ZL3073X_NUM_REFS; i++) {
 		rc = zl3073x_ref_state_fetch(zldev, i);
 		if (rc) {
@@ -1033,6 +1038,14 @@ 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");
+	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 78dc208f3eea2a..67c10e2595118c 100644
--- a/drivers/dpll/zl3073x/core.h
+++ b/drivers/dpll/zl3073x/core.h
@@ -26,6 +26,10 @@ 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_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)
 
 enum zl3073x_flags {
 	ZL3073X_FLAG_REF_PHASE_COMP_32_BIT,
@@ -55,6 +59,8 @@ 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
  * @synth: array of synths' invariants
@@ -63,6 +69,7 @@ struct zl3073x_chip_info {
  * @kworker: thread for periodic work
  * @work: periodic work
  * @clock_id: clock id of the device
+ * @out_step_time_mask: output step-time mask (device-global)
  * @phase_avg_factor: phase offset measurement averaging factor
  * @freq_monitor: is frequency monitor enabled
  */
@@ -71,6 +78,8 @@ 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 */
 	struct zl3073x_ref	ref[ZL3073X_NUM_REFS];
@@ -87,6 +96,7 @@ struct zl3073x_dev {
 
 	/* Per-chip parameters */
 	u64			clock_id;
+	u16			out_step_time_mask;
 	u8			phase_avg_factor;
 	bool			freq_monitor;
 };
@@ -308,6 +318,19 @@ zl3073x_dev_out_is_enabled(struct zl3073x_dev *zldev, u8 index)
 	return zl3073x_synth_is_enabled(synth) && zl3073x_out_is_enabled(out);
 }
 
+/**
+ * zl3073x_dev_out_is_stepped - check if output is in step-time mask
+ * @zldev: pointer to zl3073x device
+ * @index: output index
+ *
+ * Return: true if output is affected by step-time operations
+ */
+static inline bool
+zl3073x_dev_out_is_stepped(struct zl3073x_dev *zldev, u8 index)
+{
+	return !!(zldev->out_step_time_mask & BIT(index));
+}
+
 /**
  * zl3073x_dev_out_dpll_get - get DPLL ID the output is driven by
  * @zldev: pointer to zl3073x device
diff --git a/drivers/dpll/zl3073x/regs.h b/drivers/dpll/zl3073x/regs.h
index b70ead7d4495b2..f3a5e1215aa36b 100644
--- a/drivers/dpll/zl3073x/regs.h
+++ b/drivers/dpll/zl3073x/regs.h
@@ -179,6 +179,20 @@
 #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, ZL3073X_MAX_CHANNELS, 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 +207,9 @@
 
 /*******************************
  * 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 +219,24 @@
 	((_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)
+#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 +256,23 @@
 #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)
+
+#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 10, Ref Mailbox
  *******************************/
-- 
2.54.0

[PATCH net-next v4 2/2] 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 regardless of the initial channel
state, providing gettimex64, settime64, adjtime, adjfine, adjphase
and getmaxphase callbacks.

Callback availability depends on the current channel state:
- adjfine: when NCO pin is connected (returns -EOPNOTSUPP otherwise)
- adjphase: available when tracking a reference, uses TIE write
- adjtime: always available and uses
  * phase step for sub-second deltas when NCO pin is connected
  * TIE write when tracking a reference
  * plain ToD read-modify-write otherwise
- gettime/settime: always available

The adjtime callback splits multi-second adjustments into a ToD
read-modify-write for the seconds part and a sub-second mechanism
(phase step or TIE write) for the remainder. On partial failure
where seconds were already committed, success is returned to
prevent the PTP servo from retrying and applying seconds again.

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

Reviewed-by: Petr Oros <poros@redhat.com>
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  | 425 ++++++++++++++++++++++++++++++++---
 drivers/dpll/zl3073x/dpll.h  |   5 +
 3 files changed, 408 insertions(+), 28 deletions(-)

diff --git a/drivers/dpll/zl3073x/Kconfig b/drivers/dpll/zl3073x/Kconfig
index 5bbca140058131..da1731ace15f02 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
 	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
 	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
 	select REGMAP_SPI
 	select ZL3073X
 	help
diff --git a/drivers/dpll/zl3073x/dpll.c b/drivers/dpll/zl3073x/dpll.c
index 0488ae6ac486c8..5e294f190505fc 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>
@@ -13,6 +14,7 @@
 #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>
 
@@ -2275,45 +2277,369 @@ zl3073x_dpll_init_fine_phase_adjust(struct zl3073x_dev *zldev)
 	return zl3073x_write_u8(zldev, ZL_REG_SYNTH_PHASE_SHIFT_CTRL, 0x01);
 }
 
+/* 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 for NCO.
+ *
+ * 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;
+	struct zl3073x_dpll_pin *pin;
+	u32 first_synth_freq = 0;
+	bool tod_stepped = false;
+	s32 step_cycles;
+	u32 synth_freq;
+	int rc;
+	u8 i;
+
+	/* 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_dev_out_is_stepped(zldev, 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 NCO, 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
  */
-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;
+	const struct zl3073x_chan *chan;
+	bool sec_adjusted = false;
+	struct timespec64 ts;
+	int rc;
 
-	mutex_destroy(&zldpll->lock);
-	kfree(zldpll);
+	if (!delta)
+		return 0;
+
+	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 mechanism
+	 * (phase step or TIE write).
+	 */
+	if (delta >= NSEC_PER_SEC || 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;
+
+		/* No sub-second remainder, done */
+		if (!delta)
+			return 0;
+
+		/* Wait for the ToD write to be applied at the 1 Hz edge
+		 * before issuing phase step or TIE write, so the pending
+		 * WR_NEXT_1HZ does not overwrite the sub-second adjustment.
+		 */
+		rc = zl3073x_chan_tod_ready_wait(zldev, zldpll->id);
+		if (rc)
+			return rc;
+
+		sec_adjusted = true;
+	}
+
+	/* 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 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/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,
+			 "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)
+ *
+ * Only supported for NCO. Writes the delta frequency offset register.
+ *
+ * Return: 0 on success, -EOPNOTSUPP if NCO pin is not connected, <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 (!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;
+}
+
+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,
+	.adjphase	= zl3073x_dpll_ptp_adjphase,
+	.getmaxphase	= zl3073x_dpll_ptp_getmaxphase,
+};
+
+/**
+ * zl3073x_dpll_ptp_register - register PTP clock for a DPLL channel
+ * @zldpll: DPLL channel to register PTP clock for
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int zl3073x_dpll_ptp_register(struct zl3073x_dpll *zldpll)
+{
+	struct zl3073x_dev *zldev = zldpll->dev;
+	struct ptp_clock *ptp_clock;
+
+	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;
+	}
 }
 
 /**
@@ -2398,6 +2724,48 @@ 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
@@ -2428,6 +2796,13 @@ 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;
 }
 
@@ -2441,7 +2816,7 @@ 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 faebc402ba1b70..993221dc63249d 100644
--- a/drivers/dpll/zl3073x/dpll.h
+++ b/drivers/dpll/zl3073x/dpll.h
@@ -5,6 +5,7 @@
 
 #include <linux/dpll.h>
 #include <linux/list.h>
+#include <linux/ptp_clock_kernel.h>
 
 #include "core.h"
 
@@ -22,6 +23,8 @@
  * @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 +39,8 @@ 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);
-- 
2.54.0

Re: [PATCH net-next v4 1/2] dpll: zl3073x: add channel ToD, phase step and TIE operations

[Vadim Fedorenko]

On 03/08/2026 15:06, Ivan Vecera wrote:
> Add low-level DPLL channel operations for ToD read/write/adjust,
> output phase step, delta frequency offset write and TIE (Time
> Interval Error) write. These serve as building blocks for the PTP
> clock callbacks added in the next patch.
> 
> ToD operations use a wait-before-write pattern to avoid blocking
> after each operation.
> 
> 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.
> 
> The TIE write operation provides sub-picosecond resolution phase
> adjustment for modes where the DPLL is tracking a reference
> (AUTO and REFLOCK).
> 
> Add output step-time mask to struct zl3073x_dev and
> zl3073x_dev_out_is_stepped() helper to check if an output
> participates in step-time operations.
> 
> Reviewed-by: Petr Oros <poros@redhat.com>
> Tested-by: Chris du Quesnay <Chris.duQuesnay@microchip.com>
> Signed-off-by: Ivan Vecera <ivecera@redhat.com>
> ---
>   drivers/dpll/zl3073x/chan.c | 310 +++++++++++++++++++++++++++++++++++-
>   drivers/dpll/zl3073x/chan.h |  32 ++++
>   drivers/dpll/zl3073x/core.c |  13 ++
>   drivers/dpll/zl3073x/core.h |  23 +++
>   drivers/dpll/zl3073x/regs.h |  52 ++++++
>   5 files changed, 428 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dpll/zl3073x/chan.c b/drivers/dpll/zl3073x/chan.c
> index 4ec2cf53dad468..79874a9fdb4962 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>
>   
> @@ -162,8 +163,8 @@ int zl3073x_chan_nco_mode_set(struct zl3073x_dev *zldev, u8 index)
>    * @zldev: pointer to zl3073x_dev structure
>    * @index: DPLL channel index to fetch state for
>    *
> - * Reads the mode_refsel register and reference priority registers for
> - * the given DPLL channel and stores the raw values for later use.
> + * Reads the mode_refsel, status and reference priority registers for
> + * the given DPLL channel and stores the values for later use.
>    *
>    * Return: 0 on success, <0 on error
>    */
> @@ -234,6 +235,311 @@ 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
> + */
> +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;
> +	}

there are 3 cmds defined, but FIELD_GET(ZL_DPLL_TOD_CTRL_CMD) can return
up to 16 possible values. I would explicitly put defined commands in
cases and make default to ENOTSUPP..

> +
> +	rc = zl3073x_poll_zero_u8(zldev, ZL_REG_DPLL_TOD_CTRL(ch),
> +				  ZL_DPLL_TOD_CTRL_SEM, timeout);
> +
> +	return rc == -ETIMEDOUT ? -EBUSY : rc;
> +}

[...]

> +#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

Re: [PATCH net-next v4 1/2] dpll: zl3073x: add channel ToD, phase step and TIE operations

[Ivan Vecera]

On 8/5/26 1:07 AM, Vadim Fedorenko wrote:
> On 03/08/2026 15:06, Ivan Vecera wrote:
>> Add low-level DPLL channel operations for ToD read/write/adjust,
>> output phase step, delta frequency offset write and TIE (Time
>> Interval Error) write. These serve as building blocks for the PTP
>> clock callbacks added in the next patch.
>>
>> ToD operations use a wait-before-write pattern to avoid blocking
>> after each operation.
>>
>> 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.
>>
>> The TIE write operation provides sub-picosecond resolution phase
>> adjustment for modes where the DPLL is tracking a reference
>> (AUTO and REFLOCK).
>>
>> Add output step-time mask to struct zl3073x_dev and
>> zl3073x_dev_out_is_stepped() helper to check if an output
>> participates in step-time operations.
>>
>> Reviewed-by: Petr Oros <poros@redhat.com>
>> Tested-by: Chris du Quesnay <Chris.duQuesnay@microchip.com>
>> Signed-off-by: Ivan Vecera <ivecera@redhat.com>
>> ---
>>   drivers/dpll/zl3073x/chan.c | 310 +++++++++++++++++++++++++++++++++++-
>>   drivers/dpll/zl3073x/chan.h |  32 ++++
>>   drivers/dpll/zl3073x/core.c |  13 ++
>>   drivers/dpll/zl3073x/core.h |  23 +++
>>   drivers/dpll/zl3073x/regs.h |  52 ++++++
>>   5 files changed, 428 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/dpll/zl3073x/chan.c b/drivers/dpll/zl3073x/chan.c
>> index 4ec2cf53dad468..79874a9fdb4962 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>
>> @@ -162,8 +163,8 @@ int zl3073x_chan_nco_mode_set(struct zl3073x_dev 
>> *zldev, u8 index)
>>    * @zldev: pointer to zl3073x_dev structure
>>    * @index: DPLL channel index to fetch state for
>>    *
>> - * Reads the mode_refsel register and reference priority registers for
>> - * the given DPLL channel and stores the raw values for later use.
>> + * Reads the mode_refsel, status and reference priority registers for
>> + * the given DPLL channel and stores the values for later use.
>>    *
>>    * Return: 0 on success, <0 on error
>>    */
>> @@ -234,6 +235,311 @@ 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
>> + */
>> +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;
>> +    }
> 
> there are 3 cmds defined, but FIELD_GET(ZL_DPLL_TOD_CTRL_CMD) can return
> up to 16 possible values. I would explicitly put defined commands in
> cases and make default to ENOTSUPP..

Hi Vadim,
the ZL_DPLL_TOD_CTRL_CMD bits are never filled by firmware (only the
semaphore bit) so the driver knows what it writes. So such check is not
necessary but if you want it I can add something like:

...
     case ZL_DPLL_TOD_CTRL_CMD_RD_CURRENT:
     case ZL_DPLL_TOD_CTRL_CMD_RD_NEXT_1HZ:
         timeout = ZL_POLL_TOD_RD_TIMEOUT_US;
         break;
     default:
         WARN_ON(1); /* this is really unexpected */
         return -ENOTSUPP;
...

Let me know.

Thanks,
Ivan

Re: [PATCH net-next v4 1/2] dpll: zl3073x: add channel ToD, phase step and TIE operations

[Vadim Fedorenko]

On 05/08/2026 10:48, Ivan Vecera wrote:
> On 8/5/26 1:07 AM, Vadim Fedorenko wrote:
>> On 03/08/2026 15:06, Ivan Vecera wrote:
>>> Add low-level DPLL channel operations for ToD read/write/adjust,
>>> output phase step, delta frequency offset write and TIE (Time
>>> Interval Error) write. These serve as building blocks for the PTP
>>> clock callbacks added in the next patch.
>>>
>>> ToD operations use a wait-before-write pattern to avoid blocking
>>> after each operation.
>>>
>>> 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.
>>>
>>> The TIE write operation provides sub-picosecond resolution phase
>>> adjustment for modes where the DPLL is tracking a reference
>>> (AUTO and REFLOCK).
>>>
>>> Add output step-time mask to struct zl3073x_dev and
>>> zl3073x_dev_out_is_stepped() helper to check if an output
>>> participates in step-time operations.
>>>
>>> Reviewed-by: Petr Oros <poros@redhat.com>
>>> Tested-by: Chris du Quesnay <Chris.duQuesnay@microchip.com>
>>> Signed-off-by: Ivan Vecera <ivecera@redhat.com>
>>> ---
>>>   drivers/dpll/zl3073x/chan.c | 310 +++++++++++++++++++++++++++++++++++-
>>>   drivers/dpll/zl3073x/chan.h |  32 ++++
>>>   drivers/dpll/zl3073x/core.c |  13 ++
>>>   drivers/dpll/zl3073x/core.h |  23 +++
>>>   drivers/dpll/zl3073x/regs.h |  52 ++++++
>>>   5 files changed, 428 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/dpll/zl3073x/chan.c b/drivers/dpll/zl3073x/chan.c
>>> index 4ec2cf53dad468..79874a9fdb4962 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>
>>> @@ -162,8 +163,8 @@ int zl3073x_chan_nco_mode_set(struct zl3073x_dev 
>>> *zldev, u8 index)
>>>    * @zldev: pointer to zl3073x_dev structure
>>>    * @index: DPLL channel index to fetch state for
>>>    *
>>> - * Reads the mode_refsel register and reference priority registers for
>>> - * the given DPLL channel and stores the raw values for later use.
>>> + * Reads the mode_refsel, status and reference priority registers for
>>> + * the given DPLL channel and stores the values for later use.
>>>    *
>>>    * Return: 0 on success, <0 on error
>>>    */
>>> @@ -234,6 +235,311 @@ 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
>>> + */
>>> +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;
>>> +    }
>>
>> there are 3 cmds defined, but FIELD_GET(ZL_DPLL_TOD_CTRL_CMD) can return
>> up to 16 possible values. I would explicitly put defined commands in
>> cases and make default to ENOTSUPP..
> 
> Hi Vadim,
> the ZL_DPLL_TOD_CTRL_CMD bits are never filled by firmware (only the
> semaphore bit) so the driver knows what it writes. So such check is not
> necessary but if you want it I can add something like:
> 
> ...
>      case ZL_DPLL_TOD_CTRL_CMD_RD_CURRENT:
>      case ZL_DPLL_TOD_CTRL_CMD_RD_NEXT_1HZ:
>          timeout = ZL_POLL_TOD_RD_TIMEOUT_US;
>          break;
>      default:
>          WARN_ON(1); /* this is really unexpected */
>          return -ENOTSUPP;
> ...

This looks a bit more safe, especially now while the driver is in active
development. Let's add this part.

Thanks

> 
> Let me know.
> 
> Thanks,
> Ivan
> 

Re: [PATCH net-next v4 1/2] dpll: zl3073x: add channel ToD, phase step and TIE operations

[Ivan Vecera]

On 8/5/26 12:03 PM, Vadim Fedorenko wrote:
> On 05/08/2026 10:48, Ivan Vecera wrote:
>> On 8/5/26 1:07 AM, Vadim Fedorenko wrote:
>>> On 03/08/2026 15:06, Ivan Vecera wrote:
>>>> Add low-level DPLL channel operations for ToD read/write/adjust,
>>>> output phase step, delta frequency offset write and TIE (Time
>>>> Interval Error) write. These serve as building blocks for the PTP
>>>> clock callbacks added in the next patch.
>>>>
>>>> ToD operations use a wait-before-write pattern to avoid blocking
>>>> after each operation.
>>>>
>>>> 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.
>>>>
>>>> The TIE write operation provides sub-picosecond resolution phase
>>>> adjustment for modes where the DPLL is tracking a reference
>>>> (AUTO and REFLOCK).
>>>>
>>>> Add output step-time mask to struct zl3073x_dev and
>>>> zl3073x_dev_out_is_stepped() helper to check if an output
>>>> participates in step-time operations.
>>>>
>>>> Reviewed-by: Petr Oros <poros@redhat.com>
>>>> Tested-by: Chris du Quesnay <Chris.duQuesnay@microchip.com>
>>>> Signed-off-by: Ivan Vecera <ivecera@redhat.com>
>>>> ---
>>>>   drivers/dpll/zl3073x/chan.c | 310 ++++++++++++++++++++++++++++++++ 
>>>> +++-
>>>>   drivers/dpll/zl3073x/chan.h |  32 ++++
>>>>   drivers/dpll/zl3073x/core.c |  13 ++
>>>>   drivers/dpll/zl3073x/core.h |  23 +++
>>>>   drivers/dpll/zl3073x/regs.h |  52 ++++++
>>>>   5 files changed, 428 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/dpll/zl3073x/chan.c b/drivers/dpll/zl3073x/chan.c
>>>> index 4ec2cf53dad468..79874a9fdb4962 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>
>>>> @@ -162,8 +163,8 @@ int zl3073x_chan_nco_mode_set(struct zl3073x_dev 
>>>> *zldev, u8 index)
>>>>    * @zldev: pointer to zl3073x_dev structure
>>>>    * @index: DPLL channel index to fetch state for
>>>>    *
>>>> - * Reads the mode_refsel register and reference priority registers for
>>>> - * the given DPLL channel and stores the raw values for later use.
>>>> + * Reads the mode_refsel, status and reference priority registers for
>>>> + * the given DPLL channel and stores the values for later use.
>>>>    *
>>>>    * Return: 0 on success, <0 on error
>>>>    */
>>>> @@ -234,6 +235,311 @@ 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
>>>> + */
>>>> +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;
>>>> +    }
>>>
>>> there are 3 cmds defined, but FIELD_GET(ZL_DPLL_TOD_CTRL_CMD) can return
>>> up to 16 possible values. I would explicitly put defined commands in
>>> cases and make default to ENOTSUPP..
>>
>> Hi Vadim,
>> the ZL_DPLL_TOD_CTRL_CMD bits are never filled by firmware (only the
>> semaphore bit) so the driver knows what it writes. So such check is not
>> necessary but if you want it I can add something like:
>>
>> ...
>>      case ZL_DPLL_TOD_CTRL_CMD_RD_CURRENT:
>>      case ZL_DPLL_TOD_CTRL_CMD_RD_NEXT_1HZ:
>>          timeout = ZL_POLL_TOD_RD_TIMEOUT_US;
>>          break;
>>      default:
>>          WARN_ON(1); /* this is really unexpected */
>>          return -ENOTSUPP;
>> ...
> 
> This looks a bit more safe, especially now while the driver is in active
> development. Let's add this part.
> 
> Thanks

OK, will update in v5.

Thanks,
Ivan