firmware: arm_scmi: Implement is_notify_supported callback in reset protocol

Add a preliminary check to verify if the reset protocol related notify
enable commands are supported at all by the SCMI platform, and then
provide the callback needed to allow the core SCMI notification
subsytem to do a fine-grain check if a specific resource domain
supports notifications.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20240212123233.1230090-9-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

1 files changed, 29 insertions, 8 deletions

diff --git a/drivers/firmware/arm_scmi/reset.c b/drivers/firmware/arm_scmi/reset.c
index 19970d9f9e36..1b318316535e 100644
--- a/drivers/firmware/arm_scmi/reset.c
+++ b/drivers/firmware/arm_scmi/reset.c
@@ -67,6 +67,7 @@ struct reset_dom_info {
 struct scmi_reset_info {
 	u32 version;
 	int num_domains;
+	bool notify_reset_cmd;
 	struct reset_dom_info *dom_info;
 };
 
@@ -89,18 +90,24 @@ static int scmi_reset_attributes_get(const struct scmi_protocol_handle *ph,
 	}
 
 	ph->xops->xfer_put(ph, t);
+
+	if (!ret)
+		if (!ph->hops->protocol_msg_check(ph, RESET_NOTIFY, NULL))
+			pi->notify_reset_cmd = true;
+
 	return ret;
 }
 
 static int
 scmi_reset_domain_attributes_get(const struct scmi_protocol_handle *ph,
-				 u32 domain, struct reset_dom_info *dom_info,
-				 u32 version)
+				 struct scmi_reset_info *pinfo,
+				 u32 domain, u32 version)
 {
 	int ret;
 	u32 attributes;
 	struct scmi_xfer *t;
 	struct scmi_msg_resp_reset_domain_attributes *attr;
+	struct reset_dom_info *dom_info = pinfo->dom_info + domain;
 
 	ret = ph->xops->xfer_get_init(ph, RESET_DOMAIN_ATTRIBUTES,
 				      sizeof(domain), sizeof(*attr), &t);
@@ -115,7 +122,9 @@ scmi_reset_domain_attributes_get(const struct scmi_protocol_handle *ph,
 		attributes = le32_to_cpu(attr->attributes);
 
 		dom_info->async_reset = SUPPORTS_ASYNC_RESET(attributes);
-		dom_info->reset_notify = SUPPORTS_NOTIFY_RESET(attributes);
+		if (pinfo->notify_reset_cmd)
+			dom_info->reset_notify =
+				SUPPORTS_NOTIFY_RESET(attributes);
 		dom_info->latency_us = le32_to_cpu(attr->latency);
 		if (dom_info->latency_us == U32_MAX)
 			dom_info->latency_us = 0;
@@ -226,6 +235,20 @@ static const struct scmi_reset_proto_ops reset_proto_ops = {
 	.deassert = scmi_reset_domain_deassert,
 };
 
+static bool scmi_reset_notify_supported(const struct scmi_protocol_handle *ph,
+					u8 evt_id, u32 src_id)
+{
+	struct reset_dom_info *dom;
+	struct scmi_reset_info *pi = ph->get_priv(ph);
+
+	if (evt_id != SCMI_EVENT_RESET_ISSUED || src_id >= pi->num_domains)
+		return false;
+
+	dom = pi->dom_info + src_id;
+
+	return dom->reset_notify;
+}
+
 static int scmi_reset_notify(const struct scmi_protocol_handle *ph,
 			     u32 domain_id, bool enable)
 {
@@ -301,6 +324,7 @@ static const struct scmi_event reset_events[] = {
 };
 
 static const struct scmi_event_ops reset_event_ops = {
+	.is_notify_supported = scmi_reset_notify_supported,
 	.get_num_sources = scmi_reset_get_num_sources,
 	.set_notify_enabled = scmi_reset_set_notify_enabled,
 	.fill_custom_report = scmi_reset_fill_custom_report,
@@ -339,11 +363,8 @@ static int scmi_reset_protocol_init(const struct scmi_protocol_handle *ph)
 	if (!pinfo->dom_info)
 		return -ENOMEM;
 
-	for (domain = 0; domain < pinfo->num_domains; domain++) {
-		struct reset_dom_info *dom = pinfo->dom_info + domain;
-
-		scmi_reset_domain_attributes_get(ph, domain, dom, version);
-	}
+	for (domain = 0; domain < pinfo->num_domains; domain++)
+		scmi_reset_domain_attributes_get(ph, pinfo, domain, version);
 
 	pinfo->version = version;
 	return ph->set_priv(ph, pinfo, version);