firmware: arm_scmi: Implement is_notify_supported callback in clock protocol

Add a preliminary check to verify if the clock 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/20240212123233.1230090-7-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

1 files changed, 43 insertions, 4 deletions

diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
index 959e48aba1b54..85eda5db40bab 100644
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -158,6 +158,8 @@ struct clock_info {
 	u32 version;
 	int num_clocks;
 	int max_async_req;
+	bool notify_rate_changed_cmd;
+	bool notify_rate_change_requested_cmd;
 	atomic_t cur_async_req;
 	struct scmi_clock_info *clk;
 	int (*clock_config_set)(const struct scmi_protocol_handle *ph,
@@ -204,6 +206,17 @@ scmi_clock_protocol_attributes_get(const struct scmi_protocol_handle *ph,
 	}
 
 	ph->xops->xfer_put(ph, t);
+
+	if (!ret) {
+		if (!ph->hops->protocol_msg_check(ph, CLOCK_RATE_NOTIFY, NULL))
+			ci->notify_rate_changed_cmd = true;
+
+		if (!ph->hops->protocol_msg_check(ph,
+						  CLOCK_RATE_CHANGE_REQUESTED_NOTIFY,
+						  NULL))
+			ci->notify_rate_change_requested_cmd = true;
+	}
+
 	return ret;
 }
 
@@ -329,13 +342,14 @@ scmi_clock_get_permissions(const struct scmi_protocol_handle *ph, u32 clk_id,
 }
 
 static int scmi_clock_attributes_get(const struct scmi_protocol_handle *ph,
-				     u32 clk_id, struct scmi_clock_info *clk,
+				     u32 clk_id, struct clock_info *cinfo,
 				     u32 version)
 {
 	int ret;
 	u32 attributes;
 	struct scmi_xfer *t;
 	struct scmi_msg_resp_clock_attributes *attr;
+	struct scmi_clock_info *clk = cinfo->clk + clk_id;
 
 	ret = ph->xops->xfer_get_init(ph, CLOCK_ATTRIBUTES,
 				      sizeof(clk_id), sizeof(*attr), &t);
@@ -368,9 +382,11 @@ static int scmi_clock_attributes_get(const struct scmi_protocol_handle *ph,
 						    NULL, clk->name,
 						    SCMI_MAX_STR_SIZE);
 
-		if (SUPPORTS_RATE_CHANGED_NOTIF(attributes))
+		if (cinfo->notify_rate_changed_cmd &&
+		    SUPPORTS_RATE_CHANGED_NOTIF(attributes))
 			clk->rate_changed_notifications = true;
-		if (SUPPORTS_RATE_CHANGE_REQUESTED_NOTIF(attributes))
+		if (cinfo->notify_rate_change_requested_cmd &&
+		    SUPPORTS_RATE_CHANGE_REQUESTED_NOTIF(attributes))
 			clk->rate_change_requested_notifications = true;
 		if (SUPPORTS_PARENT_CLOCK(attributes))
 			scmi_clock_possible_parents(ph, clk_id, clk);
@@ -896,6 +912,28 @@ static const struct scmi_clk_proto_ops clk_proto_ops = {
 	.parent_get = scmi_clock_get_parent,
 };
 
+static bool scmi_clk_notify_supported(const struct scmi_protocol_handle *ph,
+				      u8 evt_id, u32 src_id)
+{
+	bool supported;
+	struct scmi_clock_info *clk;
+	struct clock_info *ci = ph->get_priv(ph);
+
+	if (evt_id >= ARRAY_SIZE(evt_2_cmd))
+		return false;
+
+	clk = scmi_clock_domain_lookup(ci, src_id);
+	if (IS_ERR(clk))
+		return false;
+
+	if (evt_id == SCMI_EVENT_CLOCK_RATE_CHANGED)
+		supported = clk->rate_changed_notifications;
+	else
+		supported = clk->rate_change_requested_notifications;
+
+	return supported;
+}
+
 static int scmi_clk_rate_notify(const struct scmi_protocol_handle *ph,
 				u32 clk_id, int message_id, bool enable)
 {
@@ -980,6 +1018,7 @@ static const struct scmi_event clk_events[] = {
 };
 
 static const struct scmi_event_ops clk_event_ops = {
+	.is_notify_supported = scmi_clk_notify_supported,
 	.get_num_sources = scmi_clk_get_num_sources,
 	.set_notify_enabled = scmi_clk_set_notify_enabled,
 	.fill_custom_report = scmi_clk_fill_custom_report,
@@ -1021,7 +1060,7 @@ static int scmi_clock_protocol_init(const struct scmi_protocol_handle *ph)
 	for (clkid = 0; clkid < cinfo->num_clocks; clkid++) {
 		struct scmi_clock_info *clk = cinfo->clk + clkid;
 
-		ret = scmi_clock_attributes_get(ph, clkid, clk, version);
+		ret = scmi_clock_attributes_get(ph, clkid, cinfo, version);
 		if (!ret)
 			scmi_clock_describe_rates_get(ph, clkid, clk);
 	}