Merge: CNB97: dpll: add phase-offset-monitor feature

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/7158

JIRA: https://issues.redhat.com/browse/RHEL-105066

This adds phase-offset-monitor feature into DPLL subsystem.

Signed-off-by: Ivan Vecera <ivecera@redhat.com>

Approved-by: Petr Oros <poros@redhat.com>
Approved-by: Murphy Zhou <xzhou@redhat.com>
Approved-by: mheib <mheib@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Augusto Caringi <acaringi@redhat.com>

Author: caringi

Documentation/driver-api/dpll.rst

@@ -214,6 +214,24 @@ offset values are fractional with 3-digit decimal places and shell be
 divided with ``DPLL_PIN_PHASE_OFFSET_DIVIDER`` to get integer part and
 modulo divided to get fractional part.
 
+Phase offset monitor
+====================
+
+Phase offset measurement is typically performed against the current active
+source. However, some DPLL (Digital Phase-Locked Loop) devices may offer
+the capability to monitor phase offsets across all available inputs.
+The attribute and current feature state shall be included in the response
+message of the ``DPLL_CMD_DEVICE_GET`` command for supported DPLL devices.
+In such cases, users can also control the feature using the
+``DPLL_CMD_DEVICE_SET`` command by setting the ``enum dpll_feature_state``
+values for the attribute.
+Once enabled the phase offset measurements for the input shall be returned
+in the ``DPLL_A_PIN_PHASE_OFFSET`` attribute.
+
+  =============================== ========================
+  ``DPLL_A_PHASE_OFFSET_MONITOR`` attr state of a feature
+  =============================== ========================
+
 Embedded SYNC
 =============
 

Documentation/netlink/specs/dpll.yaml

@@ -240,6 +240,20 @@ definitions:
       integer part of a measured phase offset value.
       Value of (DPLL_A_PHASE_OFFSET % DPLL_PHASE_OFFSET_DIVIDER) is a
       fractional part of a measured phase offset value.
+  -
+    type: enum
+    name: feature-state
+    doc: |
+      Allow control (enable/disable) and status checking over features.
+    entries:
+      -
+        name: disable
+        doc: |
+          feature shall be disabled
+      -
+        name: enable
+        doc: |
+          feature shall be enabled
 
 attribute-sets:
   -
@@ -293,6 +307,14 @@ attribute-sets:
           be put to message multiple times to indicate possible parallel
           quality levels (e.g. one specified by ITU option 1 and another
           one specified by option 2).
+      -
+        name: phase-offset-monitor
+        type: u32
+        enum: feature-state
+        doc: Receive or request state of phase offset monitor feature.
+          If enabled, dpll device shall monitor and notify all currently
+          available inputs for changes of their phase offset against the
+          dpll device.
   -
     name: pin
     enum-name: dpll_a_pin
@@ -483,6 +505,7 @@ operations:
             - temp
             - clock-id
             - type
+            - phase-offset-monitor
 
       dump:
         reply: *dev-attrs
@@ -499,6 +522,7 @@ operations:
         request:
           attributes:
             - id
+            - phase-offset-monitor
     -
       name: device-create-ntf
       doc: Notification about device appearing

drivers/dpll/dpll_netlink.c

@@ -126,6 +126,26 @@ dpll_msg_add_mode_supported(struct sk_buff *msg, struct dpll_device *dpll,
 	return 0;
 }
 
+static int
+dpll_msg_add_phase_offset_monitor(struct sk_buff *msg, struct dpll_device *dpll,
+				  struct netlink_ext_ack *extack)
+{
+	const struct dpll_device_ops *ops = dpll_device_ops(dpll);
+	enum dpll_feature_state state;
+	int ret;
+
+	if (ops->phase_offset_monitor_set && ops->phase_offset_monitor_get) {
+		ret = ops->phase_offset_monitor_get(dpll, dpll_priv(dpll),
+						    &state, extack);
+		if (ret)
+			return ret;
+		if (nla_put_u32(msg, DPLL_A_PHASE_OFFSET_MONITOR, state))
+			return -EMSGSIZE;
+	}
+
+	return 0;
+}
+
 static int
 dpll_msg_add_lock_status(struct sk_buff *msg, struct dpll_device *dpll,
 			 struct netlink_ext_ack *extack)
@@ -591,6 +611,9 @@ dpll_device_get_one(struct dpll_device *dpll, struct sk_buff *msg,
 		return ret;
 	if (nla_put_u32(msg, DPLL_A_TYPE, dpll->type))
 		return -EMSGSIZE;
+	ret = dpll_msg_add_phase_offset_monitor(msg, dpll, extack);
+	if (ret)
+		return ret;
 
 	return 0;
 }
@@ -746,6 +769,31 @@ int dpll_pin_change_ntf(struct dpll_pin *pin)
 }
 EXPORT_SYMBOL_GPL(dpll_pin_change_ntf);
 
+static int
+dpll_phase_offset_monitor_set(struct dpll_device *dpll, struct nlattr *a,
+			      struct netlink_ext_ack *extack)
+{
+	const struct dpll_device_ops *ops = dpll_device_ops(dpll);
+	enum dpll_feature_state state = nla_get_u32(a), old_state;
+	int ret;
+
+	if (!(ops->phase_offset_monitor_set && ops->phase_offset_monitor_get)) {
+		NL_SET_ERR_MSG_ATTR(extack, a, "dpll device not capable of phase offset monitor");
+		return -EOPNOTSUPP;
+	}
+	ret = ops->phase_offset_monitor_get(dpll, dpll_priv(dpll), &old_state,
+					    extack);
+	if (ret) {
+		NL_SET_ERR_MSG(extack, "unable to get current state of phase offset monitor");
+		return ret;
+	}
+	if (state == old_state)
+		return 0;
+
+	return ops->phase_offset_monitor_set(dpll, dpll_priv(dpll), state,
+					     extack);
+}
+
 static int
 dpll_pin_freq_set(struct dpll_pin *pin, struct nlattr *a,
 		  struct netlink_ext_ack *extack)
@@ -1533,12 +1581,29 @@ int dpll_nl_device_get_doit(struct sk_buff *skb, struct genl_info *info)
 	return genlmsg_reply(msg, info);
 }
 
-int dpll_nl_device_set_doit(struct sk_buff *skb, struct genl_info *info)
+static int
+dpll_set_from_nlattr(struct dpll_device *dpll, struct genl_info *info)
 {
-	/* placeholder for set command */
+	int ret;
+
+	if (info->attrs[DPLL_A_PHASE_OFFSET_MONITOR]) {
+		struct nlattr *a = info->attrs[DPLL_A_PHASE_OFFSET_MONITOR];
+
+		ret = dpll_phase_offset_monitor_set(dpll, a, info->extack);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
+int dpll_nl_device_set_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct dpll_device *dpll = info->user_ptr[0];
+
+	return dpll_set_from_nlattr(dpll, info);
+}
+
 int dpll_nl_device_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct dpll_dump_ctx *ctx = dpll_dump_context(cb);

drivers/dpll/dpll_nl.c

@@ -37,8 +37,9 @@ static const struct nla_policy dpll_device_get_nl_policy[DPLL_A_ID + 1] = {
 };
 
 /* DPLL_CMD_DEVICE_SET - do */
-static const struct nla_policy dpll_device_set_nl_policy[DPLL_A_ID + 1] = {
+static const struct nla_policy dpll_device_set_nl_policy[DPLL_A_PHASE_OFFSET_MONITOR + 1] = {
 	[DPLL_A_ID] = { .type = NLA_U32, },
+	[DPLL_A_PHASE_OFFSET_MONITOR] = NLA_POLICY_MAX(NLA_U32, 1),
 };
 
 /* DPLL_CMD_PIN_ID_GET - do */
@@ -105,7 +106,7 @@ static const struct genl_split_ops dpll_nl_ops[] = {
 		.doit		= dpll_nl_device_set_doit,
 		.post_doit	= dpll_post_doit,
 		.policy		= dpll_device_set_nl_policy,
-		.maxattr	= DPLL_A_ID,
+		.maxattr	= DPLL_A_PHASE_OFFSET_MONITOR,
 		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
 	},
 	{

include/linux/dpll.h

@@ -30,6 +30,14 @@ struct dpll_device_ops {
 				       void *dpll_priv,
 				       unsigned long *qls,
 				       struct netlink_ext_ack *extack);
+	int (*phase_offset_monitor_set)(const struct dpll_device *dpll,
+					void *dpll_priv,
+					enum dpll_feature_state state,
+					struct netlink_ext_ack *extack);
+	int (*phase_offset_monitor_get)(const struct dpll_device *dpll,
+					void *dpll_priv,
+					enum dpll_feature_state *state,
+					struct netlink_ext_ack *extack);
 };
 
 struct dpll_pin_ops {

include/uapi/linux/dpll.h

@@ -192,6 +192,17 @@ enum dpll_pin_capabilities {
 
 #define DPLL_PHASE_OFFSET_DIVIDER	1000
 
+/**
+ * enum dpll_feature_state - Allow control (enable/disable) and status checking
+ *   over features.
+ * @DPLL_FEATURE_STATE_DISABLE: feature shall be disabled
+ * @DPLL_FEATURE_STATE_ENABLE: feature shall be enabled
+ */
+enum dpll_feature_state {
+	DPLL_FEATURE_STATE_DISABLE,
+	DPLL_FEATURE_STATE_ENABLE,
+};
+
 enum dpll_a {
 	DPLL_A_ID = 1,
 	DPLL_A_MODULE_NAME,
@@ -204,6 +215,7 @@ enum dpll_a {
 	DPLL_A_TYPE,
 	DPLL_A_LOCK_STATUS_ERROR,
 	DPLL_A_CLOCK_QUALITY_LEVEL,
+	DPLL_A_PHASE_OFFSET_MONITOR,
 
 	__DPLL_A_MAX,
 	DPLL_A_MAX = (__DPLL_A_MAX - 1)