dpll: add phase_offset_monitor_get/set callback ops

JIRA: https://issues.redhat.com/browse/RHEL-104979

commit 2952daf
Author: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Date:   Thu Jun 12 17:28:34 2025 +0200

    dpll: add phase_offset_monitor_get/set callback ops

    Add new callback operations for a dpll device:
    - phase_offset_monitor_get(..) - to obtain current state of phase offset
      monitor feature from dpll device,
    - phase_offset_monitor_set(..) - to allow feature configuration.

    Obtain the feature state value using the get callback and provide it to
    the user if the device driver implements callbacks.

    Execute the set callback upon user requests.

    Reviewed-by: Milena Olech <milena.olech@intel.com>
    Reviewed-by: Jiri Pirko <jiri@nvidia.com>
    Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
    Acked-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
    Link: https://patch.msgid.link/20250612152835.1703397-3-arkadiusz.kubalewski@intel.com
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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

Author: ivecera

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);

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 {