Merge branch 'dpll-add-pin-operational-state'

Ivan Vecera says:

====================
dpll: add pin operational state

Add pin operational state (operstate) to the DPLL subsystem to
separate administrative intent from actual hardware status.

Currently pin-state mixes what the user requested (connected,
selectable, disconnected) with what the hardware is actually doing.
This makes it difficult to diagnose situations where a user sets
a pin as selectable or connected but the hardware cannot use it
due to signal issues.

The new operstate attribute is reported inside the pin-parent-device
nest alongside the existing state and is read-only. Defined values:

  - active: pin is qualified and actively used by the DPLL
  - standby: pin is qualified but not actively used by the DPLL
  - no-signal: pin does not have a valid signal
  - qual-failed: pin signal failed qualification checks

Patch 1 adds the operstate enum, netlink attribute and the
operstate_on_dpll_get callback to the DPLL subsystem. It also
updates Documentation/driver-api/dpll.rst to describe the
separation between admin state and operational state.

Patch 2 implements the callback for ZL3073x input pins using the
reference monitor status register. It also refactors the existing
state_on_dpll_get to return purely administrative state and switches
periodic monitoring to track operstate changes.
====================

Link: https://patch.msgid.link/20260428154907.2820654-1-ivecera@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

9 files changed, 192 insertions, 55 deletions

diff --git a/Documentation/driver-api/dpll.rst b/Documentation/driver-api/dpll.rst
index 93c191b2d089..37eaef785e30 100644
--- a/Documentation/driver-api/dpll.rst
+++ b/Documentation/driver-api/dpll.rst
@@ -65,35 +65,43 @@ request, where user provides attributes that result in single pin match.
 Pin selection
 =============
 
-In general, selected pin (the one which signal is driving the dpll
-device) can be obtained from ``DPLL_A_PIN_STATE`` attribute, and only
-one pin shall be in ``DPLL_PIN_STATE_CONNECTED`` state for any dpll
-device.
+Pin state (``DPLL_A_PIN_STATE``) reflects the administrative intent set
+by the user. Pin operational state (``DPLL_A_PIN_OPERSTATE``) reflects
+what the hardware is actually doing with the pin.
 
 Pin selection can be done either manually or automatically, depending
 on hardware capabilities and active dpll device work mode
 (``DPLL_A_MODE`` attribute). The consequence is that there are
-differences for each mode in terms of available pin states, as well as
-for the states the user can request for a dpll device.
+differences for each mode in terms of available pin states the user can
+request for a dpll device.
 
-In manual mode (``DPLL_MODE_MANUAL``) the user can request or receive
-one of following pin states:
+In manual mode (``DPLL_MODE_MANUAL``) the user can request one of
+following pin states:
 
-- ``DPLL_PIN_STATE_CONNECTED`` - the pin is used to drive dpll device
-- ``DPLL_PIN_STATE_DISCONNECTED`` - the pin is not used to drive dpll
+- ``DPLL_PIN_STATE_CONNECTED`` - the pin is selected to drive dpll
   device
+- ``DPLL_PIN_STATE_DISCONNECTED`` - the pin is not selected to drive
+  dpll device
 
-In automatic mode (``DPLL_MODE_AUTOMATIC``) the user can request or
-receive one of following pin states:
+In automatic mode (``DPLL_MODE_AUTOMATIC``) the user can request one of
+following pin states:
 
 - ``DPLL_PIN_STATE_SELECTABLE`` - the pin shall be considered as valid
   input for automatic selection algorithm
 - ``DPLL_PIN_STATE_DISCONNECTED`` - the pin shall be not considered as
   a valid input for automatic selection algorithm
 
-In automatic mode (``DPLL_MODE_AUTOMATIC``) the user can only receive
-pin state ``DPLL_PIN_STATE_CONNECTED`` once automatic selection
-algorithm locks a dpll device with one of the inputs.
+The actual hardware status of a pin is reported via the operational
+state (``DPLL_A_PIN_OPERSTATE``) attribute nested under the parent
+device:
+
+- ``DPLL_PIN_OPERSTATE_ACTIVE`` - pin is qualified and actively used
+  by the DPLL
+- ``DPLL_PIN_OPERSTATE_STANDBY`` - pin is qualified but not actively
+  used by the DPLL
+- ``DPLL_PIN_OPERSTATE_NO_SIGNAL`` - pin does not have a valid signal
+- ``DPLL_PIN_OPERSTATE_QUAL_FAILED`` - pin signal failed qualification
+  checks
 
 Shared pins
 ===========
diff --git a/Documentation/netlink/specs/dpll.yaml b/Documentation/netlink/specs/dpll.yaml
index 40465a3d7fc2..c45de70a47ce 100644
--- a/Documentation/netlink/specs/dpll.yaml
+++ b/Documentation/netlink/specs/dpll.yaml
@@ -213,6 +213,27 @@ definitions:
         doc: pin enabled for automatic input selection
     render-max: true
   -
+    type: enum
+    name: pin-operstate
+    doc: |
+      defines possible operational states of a pin with respect to its
+      parent DPLL device, valid values for DPLL_A_PIN_OPERSTATE attribute
+    entries:
+      -
+        name: active
+        doc: pin is qualified and actively used by the DPLL
+        value: 1
+      -
+        name: standby
+        doc: pin is qualified but not actively used by the DPLL
+      -
+        name: no-signal
+        doc: pin does not have a valid signal
+      -
+        name: qual-failed
+        doc: pin signal failed qualification (e.g. frequency or phase monitor)
+    render-max: true
+  -
     type: flags
     name: pin-capabilities
     doc: |
@@ -488,6 +509,14 @@ attribute-sets:
           Value of (DPLL_A_PIN_MEASURED_FREQUENCY %
           DPLL_PIN_MEASURED_FREQUENCY_DIVIDER) is a fractional part
           of a measured frequency value.
+      -
+        name: operstate
+        type: u32
+        enum: pin-operstate
+        doc: |
+          Operational state of the pin with respect to its parent DPLL
+          device. Unlike state (which reflects the administrative intent),
+          operstate reflects the actual hardware status.
 
   -
     name: pin-parent-device
@@ -502,6 +531,8 @@ attribute-sets:
       -
         name: state
       -
+        name: operstate
+      -
         name: phase-offset
   -
     name: pin-parent-pin
diff --git a/drivers/dpll/dpll_netlink.c b/drivers/dpll/dpll_netlink.c
index af7ce62ec55c..05cf946b4be5 100644
--- a/drivers/dpll/dpll_netlink.c
+++ b/drivers/dpll/dpll_netlink.c
@@ -325,6 +325,30 @@ dpll_msg_add_pin_on_dpll_state(struct sk_buff *msg, struct dpll_pin *pin,
 }
 
 static int
+dpll_msg_add_pin_operstate(struct sk_buff *msg, struct dpll_pin *pin,
+			   struct dpll_pin_ref *ref,
+			   struct netlink_ext_ack *extack)
+{
+	const struct dpll_pin_ops *ops = dpll_pin_ops(ref);
+	struct dpll_device *dpll = ref->dpll;
+	enum dpll_pin_operstate operstate;
+	int ret;
+
+	if (!ops->operstate_on_dpll_get)
+		return 0;
+	ret = ops->operstate_on_dpll_get(pin,
+					  dpll_pin_on_dpll_priv(dpll, pin),
+					  dpll, dpll_priv(dpll),
+					  &operstate, extack);
+	if (ret)
+		return ret;
+	if (nla_put_u32(msg, DPLL_A_PIN_OPERSTATE, operstate))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+static int
 dpll_msg_add_pin_direction(struct sk_buff *msg, struct dpll_pin *pin,
 			   struct dpll_pin_ref *ref,
 			   struct netlink_ext_ack *extack)
@@ -652,6 +676,9 @@ dpll_msg_add_pin_dplls(struct sk_buff *msg, struct dpll_pin *pin,
 		ret = dpll_msg_add_pin_on_dpll_state(msg, pin, ref, extack);
 		if (ret)
 			goto nest_cancel;
+		ret = dpll_msg_add_pin_operstate(msg, pin, ref, extack);
+		if (ret)
+			goto nest_cancel;
 		ret = dpll_msg_add_pin_prio(msg, pin, ref, extack);
 		if (ret)
 			goto nest_cancel;
diff --git a/drivers/dpll/dpll_nl.c b/drivers/dpll/dpll_nl.c
index 1e652340a5d7..58235845fa3d 100644
--- a/drivers/dpll/dpll_nl.c
+++ b/drivers/dpll/dpll_nl.c
@@ -12,11 +12,12 @@
 #include <uapi/linux/dpll.h>
 
 /* Common nested types */
-const struct nla_policy dpll_pin_parent_device_nl_policy[DPLL_A_PIN_PHASE_OFFSET + 1] = {
+const struct nla_policy dpll_pin_parent_device_nl_policy[DPLL_A_PIN_OPERSTATE + 1] = {
 	[DPLL_A_PIN_PARENT_ID] = { .type = NLA_U32, },
 	[DPLL_A_PIN_DIRECTION] = NLA_POLICY_RANGE(NLA_U32, 1, 2),
 	[DPLL_A_PIN_PRIO] = { .type = NLA_U32, },
 	[DPLL_A_PIN_STATE] = NLA_POLICY_RANGE(NLA_U32, 1, 3),
+	[DPLL_A_PIN_OPERSTATE] = NLA_POLICY_RANGE(NLA_U32, 1, 4),
 	[DPLL_A_PIN_PHASE_OFFSET] = { .type = NLA_S64, },
 };
 
diff --git a/drivers/dpll/dpll_nl.h b/drivers/dpll/dpll_nl.h
index 7419679b6977..fa8280e3dd14 100644
--- a/drivers/dpll/dpll_nl.h
+++ b/drivers/dpll/dpll_nl.h
@@ -13,7 +13,7 @@
 #include <uapi/linux/dpll.h>
 
 /* Common nested types */
-extern const struct nla_policy dpll_pin_parent_device_nl_policy[DPLL_A_PIN_PHASE_OFFSET + 1];
+extern const struct nla_policy dpll_pin_parent_device_nl_policy[DPLL_A_PIN_OPERSTATE + 1];
 extern const struct nla_policy dpll_pin_parent_pin_nl_policy[DPLL_A_PIN_STATE + 1];
 extern const struct nla_policy dpll_reference_sync_nl_policy[DPLL_A_PIN_STATE + 1];
 
diff --git a/drivers/dpll/zl3073x/dpll.c b/drivers/dpll/zl3073x/dpll.c
index c95e93ef3ab0..6fd718696de0 100644
--- a/drivers/dpll/zl3073x/dpll.c
+++ b/drivers/dpll/zl3073x/dpll.c
@@ -38,7 +38,7 @@
  * @prio: pin priority <0, 14>
  * @esync_control: embedded sync is controllable
  * @phase_gran: phase adjustment granularity
- * @pin_state: last saved pin state
+ * @operstate: last saved operational state
  * @phase_offset: last saved pin phase offset
  * @freq_offset: last saved fractional frequency offset
  * @measured_freq: last saved measured frequency
@@ -55,7 +55,7 @@ struct zl3073x_dpll_pin {
 	u8			prio;
 	bool			esync_control;
 	s32			phase_gran;
-	enum dpll_pin_state	pin_state;
+	enum dpll_pin_operstate	operstate;
 	s64			phase_offset;
 	s64			freq_offset;
 	u32			measured_freq;
@@ -500,46 +500,41 @@ zl3073x_dpll_input_pin_phase_adjust_set(const struct dpll_pin *dpll_pin,
 }
 
 /**
- * zl3073x_dpll_ref_state_get - get status for given input pin
+ * zl3073x_dpll_ref_operstate_get - get operational state for input pin
  * @pin: pointer to pin
- * @state: place to store status
+ * @operstate: place to store operational state
  *
- * Checks current status for the given input pin and stores the value
- * to @state.
+ * Returns the actual hardware state of the pin: whether it is actively
+ * used by the DPLL, has no signal, failed qualification, or is simply
+ * not in use.
  *
  * Return: 0 on success, <0 on error
  */
 static int
-zl3073x_dpll_ref_state_get(struct zl3073x_dpll_pin *pin,
-			   enum dpll_pin_state *state)
+zl3073x_dpll_ref_operstate_get(struct zl3073x_dpll_pin *pin,
+			       enum dpll_pin_operstate *operstate)
 {
 	struct zl3073x_dpll *zldpll = pin->dpll;
 	struct zl3073x_dev *zldev = zldpll->dev;
-	const struct zl3073x_chan *chan;
-	u8 ref;
-
-	chan = zl3073x_chan_state_get(zldev, zldpll->id);
-	ref = zl3073x_input_pin_ref_get(pin->id);
+	const struct zl3073x_ref *ref;
+	u8 ref_id;
 
-	/* Check if the pin reference is connected */
-	if (ref == zl3073x_dpll_connected_ref_get(zldpll)) {
-		*state = DPLL_PIN_STATE_CONNECTED;
-		return 0;
-	}
+	ref_id = zl3073x_input_pin_ref_get(pin->id);
 
-	/* If the DPLL is running in automatic mode and the reference is
-	 * selectable and its monitor does not report any error then report
-	 * pin as selectable.
-	 */
-	if (zl3073x_chan_mode_get(chan) == ZL_DPLL_MODE_REFSEL_MODE_AUTO &&
-	    zl3073x_dev_ref_is_status_ok(zldev, ref) &&
-	    zl3073x_chan_ref_is_selectable(chan, ref)) {
-		*state = DPLL_PIN_STATE_SELECTABLE;
+	/* Check if this pin is the currently locked reference */
+	if (ref_id == zl3073x_dpll_connected_ref_get(zldpll)) {
+		*operstate = DPLL_PIN_OPERSTATE_ACTIVE;
 		return 0;
 	}
 
-	/* Otherwise report the pin as disconnected */
-	*state = DPLL_PIN_STATE_DISCONNECTED;
+	/* Check reference monitor status */
+	ref = zl3073x_ref_state_get(zldev, ref_id);
+	if (ref->mon_status & ZL_REF_MON_STATUS_LOS)
+		*operstate = DPLL_PIN_OPERSTATE_NO_SIGNAL;
+	else if (!zl3073x_ref_is_status_ok(ref))
+		*operstate = DPLL_PIN_OPERSTATE_QUAL_FAILED;
+	else
+		*operstate = DPLL_PIN_OPERSTATE_STANDBY;
 
 	return 0;
 }
@@ -552,9 +547,47 @@ zl3073x_dpll_input_pin_state_on_dpll_get(const struct dpll_pin *dpll_pin,
 					 enum dpll_pin_state *state,
 					 struct netlink_ext_ack *extack)
 {
+	struct zl3073x_dpll *zldpll = dpll_priv;
+	struct zl3073x_dpll_pin *pin = pin_priv;
+	const struct zl3073x_chan *chan;
+	u8 mode, ref;
+
+	chan = zl3073x_chan_state_get(zldpll->dev, zldpll->id);
+	ref = zl3073x_input_pin_ref_get(pin->id);
+	mode = zl3073x_chan_mode_get(chan);
+
+	switch (mode) {
+	case ZL_DPLL_MODE_REFSEL_MODE_REFLOCK:
+		if (ref == zl3073x_chan_ref_get(chan))
+			*state = DPLL_PIN_STATE_CONNECTED;
+		else
+			*state = DPLL_PIN_STATE_DISCONNECTED;
+		break;
+	case ZL_DPLL_MODE_REFSEL_MODE_AUTO:
+		if (zl3073x_chan_ref_is_selectable(chan, ref))
+			*state = DPLL_PIN_STATE_SELECTABLE;
+		else
+			*state = DPLL_PIN_STATE_DISCONNECTED;
+		break;
+	default:
+		*state = DPLL_PIN_STATE_DISCONNECTED;
+		break;
+	}
+
+	return 0;
+}
+
+static int
+zl3073x_dpll_input_pin_operstate_on_dpll_get(const struct dpll_pin *dpll_pin,
+					     void *pin_priv,
+					     const struct dpll_device *dpll,
+					     void *dpll_priv,
+					     enum dpll_pin_operstate *operstate,
+					     struct netlink_ext_ack *extack)
+{
 	struct zl3073x_dpll_pin *pin = pin_priv;
 
-	return zl3073x_dpll_ref_state_get(pin, state);
+	return zl3073x_dpll_ref_operstate_get(pin, operstate);
 }
 
 static int
@@ -1248,6 +1281,7 @@ static const struct dpll_pin_ops zl3073x_dpll_input_pin_ops = {
 	.frequency_get = zl3073x_dpll_input_pin_frequency_get,
 	.frequency_set = zl3073x_dpll_input_pin_frequency_set,
 	.measured_freq_get = zl3073x_dpll_input_pin_measured_freq_get,
+	.operstate_on_dpll_get = zl3073x_dpll_input_pin_operstate_on_dpll_get,
 	.phase_offset_get = zl3073x_dpll_input_pin_phase_offset_get,
 	.phase_adjust_get = zl3073x_dpll_input_pin_phase_adjust_get,
 	.phase_adjust_set = zl3073x_dpll_input_pin_phase_adjust_set,
@@ -1663,7 +1697,7 @@ zl3073x_dpll_pin_phase_offset_check(struct zl3073x_dpll_pin *pin)
 	 * 2) For other pins use appropriate ref_phase register if the phase
 	 *    monitor feature is enabled.
 	 */
-	if (pin->pin_state == DPLL_PIN_STATE_CONNECTED)
+	if (pin->operstate == DPLL_PIN_OPERSTATE_ACTIVE)
 		reg = ZL_REG_DPLL_PHASE_ERR_DATA(zldpll->id);
 	else if (zldpll->phase_monitor)
 		reg = ZL_REG_REF_PHASE(ref_id);
@@ -1828,7 +1862,7 @@ zl3073x_dpll_changes_check(struct zl3073x_dpll *zldpll)
 	}
 
 	list_for_each_entry(pin, &zldpll->pins, list) {
-		enum dpll_pin_state state;
+		enum dpll_pin_operstate operstate;
 		bool pin_changed = false;
 
 		/* Output pins change checks are not necessary because output
@@ -1837,18 +1871,18 @@ zl3073x_dpll_changes_check(struct zl3073x_dpll *zldpll)
 		if (!zl3073x_dpll_is_input_pin(pin))
 			continue;
 
-		rc = zl3073x_dpll_ref_state_get(pin, &state);
+		rc = zl3073x_dpll_ref_operstate_get(pin, &operstate);
 		if (rc) {
 			dev_err(dev,
-				"Failed to get %s on DPLL%u state: %pe\n",
+				"Failed to get %s on DPLL%u oper state: %pe\n",
 				pin->label, zldpll->id, ERR_PTR(rc));
 			return;
 		}
 
-		if (state != pin->pin_state) {
-			dev_dbg(dev, "%s state changed: %u->%u\n", pin->label,
-				pin->pin_state, state);
-			pin->pin_state = state;
+		if (operstate != pin->operstate) {
+			dev_dbg(dev, "%s oper state changed: %u->%u\n",
+				pin->label, pin->operstate, operstate);
+			pin->operstate = operstate;
 			pin_changed = true;
 		}
 
diff --git a/drivers/dpll/zl3073x/regs.h b/drivers/dpll/zl3073x/regs.h
index d425dc67250f..8015808bdf54 100644
--- a/drivers/dpll/zl3073x/regs.h
+++ b/drivers/dpll/zl3073x/regs.h
@@ -98,7 +98,14 @@
 
 #define ZL_REG_REF_MON_STATUS(_idx)					\
 	ZL_REG_IDX(_idx, 2, 0x02, 1, ZL3073X_NUM_REFS, 1)
-#define ZL_REF_MON_STATUS_OK			0 /* all bits zeroed */
+#define ZL_REF_MON_STATUS_OK			0
+#define ZL_REF_MON_STATUS_LOS			BIT(0)
+#define ZL_REF_MON_STATUS_SCM			BIT(1)
+#define ZL_REF_MON_STATUS_CFM			BIT(2)
+#define ZL_REF_MON_STATUS_GST			BIT(3)
+#define ZL_REF_MON_STATUS_PFM			BIT(4)
+#define ZL_REF_MON_STATUS_ESYNC			BIT(6)
+#define ZL_REF_MON_STATUS_SPLIT_XO		BIT(7)
 
 #define ZL_REG_DPLL_MON_STATUS(_idx)					\
 	ZL_REG_IDX(_idx, 2, 0x10, 1, ZL3073X_MAX_CHANNELS, 1)
diff --git a/include/linux/dpll.h b/include/linux/dpll.h
index b7277a8b484d..b6f16c884b99 100644
--- a/include/linux/dpll.h
+++ b/include/linux/dpll.h
@@ -85,6 +85,12 @@ struct dpll_pin_ops {
 				 const struct dpll_device *dpll,
 				 void *dpll_priv, enum dpll_pin_state *state,
 				 struct netlink_ext_ack *extack);
+	int (*operstate_on_dpll_get)(const struct dpll_pin *pin,
+				     void *pin_priv,
+				     const struct dpll_device *dpll,
+				     void *dpll_priv,
+				     enum dpll_pin_operstate *operstate,
+				     struct netlink_ext_ack *extack);
 	int (*state_on_pin_set)(const struct dpll_pin *pin, void *pin_priv,
 				const struct dpll_pin *parent_pin,
 				void *parent_pin_priv,
diff --git a/include/uapi/linux/dpll.h b/include/uapi/linux/dpll.h
index 871685f7c353..cb363cccf2e2 100644
--- a/include/uapi/linux/dpll.h
+++ b/include/uapi/linux/dpll.h
@@ -179,6 +179,28 @@ enum dpll_pin_state {
 };
 
 /**
+ * enum dpll_pin_operstate - defines possible operational states of a pin with
+ *   respect to its parent DPLL device, valid values for DPLL_A_PIN_OPERSTATE
+ *   attribute
+ * @DPLL_PIN_OPERSTATE_ACTIVE: pin is qualified and actively used by the DPLL
+ * @DPLL_PIN_OPERSTATE_STANDBY: pin is qualified but not actively used by the
+ *   DPLL
+ * @DPLL_PIN_OPERSTATE_NO_SIGNAL: pin does not have a valid signal
+ * @DPLL_PIN_OPERSTATE_QUAL_FAILED: pin signal failed qualification (e.g.
+ *   frequency or phase monitor)
+ */
+enum dpll_pin_operstate {
+	DPLL_PIN_OPERSTATE_ACTIVE = 1,
+	DPLL_PIN_OPERSTATE_STANDBY,
+	DPLL_PIN_OPERSTATE_NO_SIGNAL,
+	DPLL_PIN_OPERSTATE_QUAL_FAILED,
+
+	/* private: */
+	__DPLL_PIN_OPERSTATE_MAX,
+	DPLL_PIN_OPERSTATE_MAX = (__DPLL_PIN_OPERSTATE_MAX - 1)
+};
+
+/**
  * enum dpll_pin_capabilities - defines possible capabilities of a pin, valid
  *   flags on DPLL_A_PIN_CAPABILITIES attribute
  * @DPLL_PIN_CAPABILITIES_DIRECTION_CAN_CHANGE: pin direction can be changed
@@ -257,6 +279,7 @@ enum dpll_a_pin {
 	DPLL_A_PIN_PHASE_ADJUST_GRAN,
 	DPLL_A_PIN_FRACTIONAL_FREQUENCY_OFFSET_PPT,
 	DPLL_A_PIN_MEASURED_FREQUENCY,
+	DPLL_A_PIN_OPERSTATE,
 
 	__DPLL_A_PIN_MAX,
 	DPLL_A_PIN_MAX = (__DPLL_A_PIN_MAX - 1)