Merge branch 'dpll-add-reference-sync-feature'

Arkadiusz Kubalewski says:

====================
dpll: add Reference SYNC feature

The device may support the Reference SYNC feature, which allows the
combination of two inputs into a input pair. In this configuration,
clock signals from both inputs are used to synchronize the DPLL device.
The higher frequency signal is utilized for the loop bandwidth of the DPLL,
while the lower frequency signal is used to syntonize the output signal of
the DPLL device. This feature enables the provision of a high-quality loop
bandwidth signal from an external source.

A capable input provides a list of inputs that can be bound with to create
Reference SYNC. To control this feature, the user must request a
desired state for a target pin: use ``DPLL_PIN_STATE_CONNECTED`` to
enable or ``DPLL_PIN_STATE_DISCONNECTED`` to disable the feature. An input
pin can be bound to only one other pin at any given time.

Verify pins bind state/capabilities:
$ ./tools/net/ynl/pyynl/cli.py \
 --spec Documentation/netlink/specs/dpll.yaml \
 --do pin-get \
 --json '{"id":0}'
{'board-label': 'CVL-SDP22',
 'id': 0,
 [...]
 'reference-sync': [{'id': 1, 'state': 'disconnected'}],
 [...]}

Bind the pins by setting connected state between them:
$ ./tools/net/ynl/pyynl/cli.py \
 --spec Documentation/netlink/specs/dpll.yaml \
 --do pin-set \
 --json '{"id":0, "reference-sync":{"id":1, "state":"connected"}}'

Verify pins bind state:
$ ./tools/net/ynl/pyynl/cli.py \
 --spec Documentation/netlink/specs/dpll.yaml \
 --do pin-get \
 --json '{"id":0}'
{'board-label': 'CVL-SDP22',
 'id': 0,
 [...]
 'reference-sync': [{'id': 1, 'state': 'connected'}],
 [...]}

Unbind the pins by setting disconnected state between them:
$ ./tools/net/ynl/pyynl/cli.py \
 --spec Documentation/netlink/specs/dpll.yaml \
 --do pin-set \
 --json '{"id":0, "reference-sync":{"id":1, "state":"disconnected"}}'
====================

Link: https://patch.msgid.link/20250626135219.1769350-1-arkadiusz.kubalewski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 171 insertions, 19 deletions

diff --git a/drivers/dpll/dpll_netlink.c b/drivers/dpll/dpll_netlink.c
index 4619aaa18b9c..036f21cac0a9 100644
--- a/drivers/dpll/dpll_netlink.c
+++ b/drivers/dpll/dpll_netlink.c
@@ -48,6 +48,24 @@ dpll_msg_add_dev_parent_handle(struct sk_buff *msg, u32 id)
 	return 0;
 }
 
+static bool dpll_pin_available(struct dpll_pin *pin)
+{
+	struct dpll_pin_ref *par_ref;
+	unsigned long i;
+
+	if (!xa_get_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED))
+		return false;
+	xa_for_each(&pin->parent_refs, i, par_ref)
+		if (xa_get_mark(&dpll_pin_xa, par_ref->pin->id,
+				DPLL_REGISTERED))
+			return true;
+	xa_for_each(&pin->dpll_refs, i, par_ref)
+		if (xa_get_mark(&dpll_device_xa, par_ref->dpll->id,
+				DPLL_REGISTERED))
+			return true;
+	return false;
+}
+
 /**
  * dpll_msg_add_pin_handle - attach pin handle attribute to a given message
  * @msg: pointer to sk_buff message to attach a pin handle
@@ -428,6 +446,47 @@ nest_cancel:
 	return -EMSGSIZE;
 }
 
+static int
+dpll_msg_add_pin_ref_sync(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;
+	void *pin_priv, *ref_sync_pin_priv;
+	struct dpll_pin *ref_sync_pin;
+	enum dpll_pin_state state;
+	struct nlattr *nest;
+	unsigned long index;
+	int ret;
+
+	pin_priv = dpll_pin_on_dpll_priv(dpll, pin);
+	xa_for_each(&pin->ref_sync_pins, index, ref_sync_pin) {
+		if (!dpll_pin_available(ref_sync_pin))
+			continue;
+		ref_sync_pin_priv = dpll_pin_on_dpll_priv(dpll, ref_sync_pin);
+		if (WARN_ON(!ops->ref_sync_get))
+			return -EOPNOTSUPP;
+		ret = ops->ref_sync_get(pin, pin_priv, ref_sync_pin,
+					ref_sync_pin_priv, &state, extack);
+		if (ret)
+			return ret;
+		nest = nla_nest_start(msg, DPLL_A_PIN_REFERENCE_SYNC);
+		if (!nest)
+			return -EMSGSIZE;
+		if (nla_put_s32(msg, DPLL_A_PIN_ID, ref_sync_pin->id))
+			goto nest_cancel;
+		if (nla_put_s32(msg, DPLL_A_PIN_STATE, state))
+			goto nest_cancel;
+		nla_nest_end(msg, nest);
+	}
+	return 0;
+
+nest_cancel:
+	nla_nest_cancel(msg, nest);
+	return -EMSGSIZE;
+}
+
 static bool dpll_pin_is_freq_supported(struct dpll_pin *pin, u32 freq)
 {
 	int fs;
@@ -572,6 +631,10 @@ dpll_cmd_pin_get_one(struct sk_buff *msg, struct dpll_pin *pin,
 	ret = dpll_msg_add_pin_esync(msg, pin, ref, extack);
 	if (ret)
 		return ret;
+	if (!xa_empty(&pin->ref_sync_pins))
+		ret = dpll_msg_add_pin_ref_sync(msg, pin, ref, extack);
+	if (ret)
+		return ret;
 	if (xa_empty(&pin->parent_refs))
 		ret = dpll_msg_add_pin_dplls(msg, pin, extack);
 	else
@@ -665,24 +728,6 @@ __dpll_device_change_ntf(struct dpll_device *dpll)
 	return dpll_device_event_send(DPLL_CMD_DEVICE_CHANGE_NTF, dpll);
 }
 
-static bool dpll_pin_available(struct dpll_pin *pin)
-{
-	struct dpll_pin_ref *par_ref;
-	unsigned long i;
-
-	if (!xa_get_mark(&dpll_pin_xa, pin->id, DPLL_REGISTERED))
-		return false;
-	xa_for_each(&pin->parent_refs, i, par_ref)
-		if (xa_get_mark(&dpll_pin_xa, par_ref->pin->id,
-				DPLL_REGISTERED))
-			return true;
-	xa_for_each(&pin->dpll_refs, i, par_ref)
-		if (xa_get_mark(&dpll_device_xa, par_ref->dpll->id,
-				DPLL_REGISTERED))
-			return true;
-	return false;
-}
-
 /**
  * dpll_device_change_ntf - notify that the dpll device has been changed
  * @dpll: registered dpll pointer
@@ -745,7 +790,7 @@ int dpll_pin_delete_ntf(struct dpll_pin *pin)
 	return dpll_pin_event_send(DPLL_CMD_PIN_DELETE_NTF, pin);
 }
 
-static int __dpll_pin_change_ntf(struct dpll_pin *pin)
+int __dpll_pin_change_ntf(struct dpll_pin *pin)
 {
 	return dpll_pin_event_send(DPLL_CMD_PIN_CHANGE_NTF, pin);
 }
@@ -936,6 +981,108 @@ rollback:
 }
 
 static int
+dpll_pin_ref_sync_state_set(struct dpll_pin *pin,
+			    unsigned long ref_sync_pin_idx,
+			    const enum dpll_pin_state state,
+			    struct netlink_ext_ack *extack)
+
+{
+	struct dpll_pin_ref *ref, *failed;
+	const struct dpll_pin_ops *ops;
+	enum dpll_pin_state old_state;
+	struct dpll_pin *ref_sync_pin;
+	struct dpll_device *dpll;
+	unsigned long i;
+	int ret;
+
+	ref_sync_pin = xa_find(&pin->ref_sync_pins, &ref_sync_pin_idx,
+			       ULONG_MAX, XA_PRESENT);
+	if (!ref_sync_pin) {
+		NL_SET_ERR_MSG(extack, "reference sync pin not found");
+		return -EINVAL;
+	}
+	if (!dpll_pin_available(ref_sync_pin)) {
+		NL_SET_ERR_MSG(extack, "reference sync pin not available");
+		return -EINVAL;
+	}
+	ref = dpll_xa_ref_dpll_first(&pin->dpll_refs);
+	ASSERT_NOT_NULL(ref);
+	ops = dpll_pin_ops(ref);
+	if (!ops->ref_sync_set || !ops->ref_sync_get) {
+		NL_SET_ERR_MSG(extack, "reference sync not supported by this pin");
+		return -EOPNOTSUPP;
+	}
+	dpll = ref->dpll;
+	ret = ops->ref_sync_get(pin, dpll_pin_on_dpll_priv(dpll, pin),
+				ref_sync_pin,
+				dpll_pin_on_dpll_priv(dpll, ref_sync_pin),
+				&old_state, extack);
+	if (ret) {
+		NL_SET_ERR_MSG(extack, "unable to get old reference sync state");
+		return ret;
+	}
+	if (state == old_state)
+		return 0;
+	xa_for_each(&pin->dpll_refs, i, ref) {
+		ops = dpll_pin_ops(ref);
+		dpll = ref->dpll;
+		ret = ops->ref_sync_set(pin, dpll_pin_on_dpll_priv(dpll, pin),
+					ref_sync_pin,
+					dpll_pin_on_dpll_priv(dpll,
+							      ref_sync_pin),
+					state, extack);
+		if (ret) {
+			failed = ref;
+			NL_SET_ERR_MSG_FMT(extack, "reference sync set failed for dpll_id:%u",
+					   dpll->id);
+			goto rollback;
+		}
+	}
+	__dpll_pin_change_ntf(pin);
+
+	return 0;
+
+rollback:
+	xa_for_each(&pin->dpll_refs, i, ref) {
+		if (ref == failed)
+			break;
+		ops = dpll_pin_ops(ref);
+		dpll = ref->dpll;
+		if (ops->ref_sync_set(pin, dpll_pin_on_dpll_priv(dpll, pin),
+				      ref_sync_pin,
+				      dpll_pin_on_dpll_priv(dpll, ref_sync_pin),
+				      old_state, extack))
+			NL_SET_ERR_MSG(extack, "set reference sync rollback failed");
+	}
+	return ret;
+}
+
+static int
+dpll_pin_ref_sync_set(struct dpll_pin *pin, struct nlattr *nest,
+		      struct netlink_ext_ack *extack)
+{
+	struct nlattr *tb[DPLL_A_PIN_MAX + 1];
+	enum dpll_pin_state state;
+	u32 sync_pin_id;
+
+	nla_parse_nested(tb, DPLL_A_PIN_MAX, nest,
+			 dpll_reference_sync_nl_policy, extack);
+	if (!tb[DPLL_A_PIN_ID]) {
+		NL_SET_ERR_MSG(extack, "sync pin id expected");
+		return -EINVAL;
+	}
+	sync_pin_id = nla_get_u32(tb[DPLL_A_PIN_ID]);
+
+	if (!tb[DPLL_A_PIN_STATE]) {
+		NL_SET_ERR_MSG(extack, "sync pin state expected");
+		return -EINVAL;
+	}
+	state = nla_get_u32(tb[DPLL_A_PIN_STATE]);
+
+	return dpll_pin_ref_sync_state_set(pin, sync_pin_id, state, extack);
+}
+
+static int
 dpll_pin_on_pin_state_set(struct dpll_pin *pin, u32 parent_idx,
 			  enum dpll_pin_state state,
 			  struct netlink_ext_ack *extack)
@@ -1241,6 +1388,11 @@ dpll_pin_set_from_nlattr(struct dpll_pin *pin, struct genl_info *info)
 			if (ret)
 				return ret;
 			break;
+		case DPLL_A_PIN_REFERENCE_SYNC:
+			ret = dpll_pin_ref_sync_set(pin, a, info->extack);
+			if (ret)
+				return ret;
+			break;
 		}
 	}