[PATCH 05/11] firmware: arm_scmi: Implement SysPower .is_notify_supported callback

[Cristian Marussi]

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

Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
---
 drivers/firmware/arm_scmi/system.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/firmware/arm_scmi/system.c b/drivers/firmware/arm_scmi/system.c
index 1621da97bcbb..b6358c155f7f 100644
--- a/drivers/firmware/arm_scmi/system.c
+++ b/drivers/firmware/arm_scmi/system.c
@@ -36,8 +36,20 @@ struct scmi_system_power_state_notifier_payld {
 struct scmi_system_info {
 	u32 version;
 	bool graceful_timeout_supported;
+	bool power_state_notify_cmd;
 };
 
+static bool scmi_system_notify_supported(const struct scmi_protocol_handle *ph,
+					 u8 evt_id, u32 src_id)
+{
+	struct scmi_system_info *pinfo = ph->get_priv(ph);
+
+	if (evt_id != SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER)
+		return false;
+
+	return pinfo->power_state_notify_cmd;
+}
+
 static int scmi_system_request_notify(const struct scmi_protocol_handle *ph,
 				      bool enable)
 {
@@ -114,6 +126,7 @@ static const struct scmi_event system_events[] = {
 };
 
 static const struct scmi_event_ops system_event_ops = {
+	.is_notify_supported = scmi_system_notify_supported,
 	.set_notify_enabled = scmi_system_set_notify_enabled,
 	.fill_custom_report = scmi_system_fill_custom_report,
 };
@@ -147,6 +160,9 @@ static int scmi_system_protocol_init(const struct scmi_protocol_handle *ph)
 	if (PROTOCOL_REV_MAJOR(pinfo->version) >= 0x2)
 		pinfo->graceful_timeout_supported = true;
 
+	if (!ph->hops->protocol_msg_check(ph, SYSTEM_POWER_STATE_NOTIFY, NULL))
+		pinfo->power_state_notify_cmd = true;
+
 	return ph->set_priv(ph, pinfo, version);
 }
 
-- 
2.43.0