drm/amd/display: Wait for ACK for INBOX0 HW Lock

[Why]
In DC we want to wait for the INBOX0 HW Lock command to ACK before
continuing. This is to ensure that the lock has been successfully
acquired before programming HW in DC.

[How]
Add interfaces to send messages on INBOX0, poll for their completation
and clear the ack.
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alvin Lee <Alvin.Lee2@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c

@@ -115,13 +115,44 @@ void dc_dmub_srv_wait_idle(struct dc_dmub_srv *dc_dmub_srv)
 	}
 }
 
+void dc_dmub_srv_clear_inbox0_ack(struct dc_dmub_srv *dmub_srv)
+{
+	struct dmub_srv *dmub = dmub_srv->dmub;
+	struct dc_context *dc_ctx = dmub_srv->ctx;
+	enum dmub_status status = DMUB_STATUS_OK;
+
+	status = dmub_srv_clear_inbox0_ack(dmub);
+	if (status != DMUB_STATUS_OK) {
+		DC_ERROR("Error clearing INBOX0 ack: status=%d\n", status);
+		dc_dmub_srv_log_diagnostic_data(dmub_srv);
+	}
+}
+
+void dc_dmub_srv_wait_for_inbox0_ack(struct dc_dmub_srv *dmub_srv)
+{
+	struct dmub_srv *dmub = dmub_srv->dmub;
+	struct dc_context *dc_ctx = dmub_srv->ctx;
+	enum dmub_status status = DMUB_STATUS_OK;
+
+	status = dmub_srv_wait_for_inbox0_ack(dmub, 100000);
+	if (status != DMUB_STATUS_OK) {
+		DC_ERROR("Error waiting for INBOX0 HW Lock Ack\n");
+		dc_dmub_srv_log_diagnostic_data(dmub_srv);
+	}
+}
+
 void dc_dmub_srv_send_inbox0_cmd(struct dc_dmub_srv *dmub_srv,
 		union dmub_inbox0_data_register data)
 {
 	struct dmub_srv *dmub = dmub_srv->dmub;
-	if (dmub->hw_funcs.send_inbox0_cmd)
-		dmub->hw_funcs.send_inbox0_cmd(dmub, data);
-	// TODO: Add wait command -- poll register for ACK
+	struct dc_context *dc_ctx = dmub_srv->ctx;
+	enum dmub_status status = DMUB_STATUS_OK;
+
+	status = dmub_srv_send_inbox0_cmd(dmub, data);
+	if (status != DMUB_STATUS_OK) {
+		DC_ERROR("Error sending INBOX0 cmd\n");
+		dc_dmub_srv_log_diagnostic_data(dmub_srv);
+	}
 }
 
 bool dc_dmub_srv_cmd_with_reply_data(struct dc_dmub_srv *dc_dmub_srv, union dmub_rb_cmd *cmd)

drivers/gpu/drm/amd/display/dc/dc_dmub_srv.h

@@ -68,6 +68,8 @@ bool dc_dmub_srv_get_dmub_outbox0_msg(const struct dc *dc, struct dmcub_trace_bu
 
 void dc_dmub_trace_event_control(struct dc *dc, bool enable);
 
+void dc_dmub_srv_clear_inbox0_ack(struct dc_dmub_srv *dmub_srv);
+void dc_dmub_srv_wait_for_inbox0_ack(struct dc_dmub_srv *dmub_srv);
 void dc_dmub_srv_send_inbox0_cmd(struct dc_dmub_srv *dmub_srv, union dmub_inbox0_data_register data);
 
 bool dc_dmub_srv_get_diagnostic_data(struct dc_dmub_srv *dc_dmub_srv, struct dmub_diagnostic_data *dmub_oca);

drivers/gpu/drm/amd/display/dc/dce/dmub_hw_lock_mgr.c

@@ -56,8 +56,11 @@ void dmub_hw_lock_mgr_inbox0_cmd(struct dc_dmub_srv *dmub_srv,
 		union dmub_inbox0_cmd_lock_hw hw_lock_cmd)
 {
 	union dmub_inbox0_data_register data = { 0 };
+
 	data.inbox0_cmd_lock_hw = hw_lock_cmd;
+	dc_dmub_srv_clear_inbox0_ack(dmub_srv);
 	dc_dmub_srv_send_inbox0_cmd(dmub_srv, data);
+	dc_dmub_srv_wait_for_inbox0_ack(dmub_srv);
 }
 
 bool should_use_dmub_lock(struct dc_link *link)

drivers/gpu/drm/amd/display/dmub/dmub_srv.h

@@ -360,6 +360,8 @@ struct dmub_srv_hw_funcs {
 
 	uint32_t (*get_gpint_dataout)(struct dmub_srv *dmub);
 
+	void (*clear_inbox0_ack_register)(struct dmub_srv *dmub);
+	uint32_t (*read_inbox0_ack_register)(struct dmub_srv *dmub);
 	void (*send_inbox0_cmd)(struct dmub_srv *dmub, union dmub_inbox0_data_register data);
 	uint32_t (*get_current_time)(struct dmub_srv *dmub);
 
@@ -735,6 +737,45 @@ bool dmub_srv_get_diagnostic_data(struct dmub_srv *dmub, struct dmub_diagnostic_
 
 bool dmub_srv_should_detect(struct dmub_srv *dmub);
 
+/**
+ * dmub_srv_send_inbox0_cmd() - Send command to DMUB using INBOX0
+ * @dmub: the dmub service
+ * @data: the data to be sent in the INBOX0 command
+ *
+ * Send command by writing directly to INBOX0 WPTR
+ *
+ * Return:
+ *   DMUB_STATUS_OK - success
+ *   DMUB_STATUS_INVALID - hw_init false or hw function does not exist
+ */
+enum dmub_status dmub_srv_send_inbox0_cmd(struct dmub_srv *dmub, union dmub_inbox0_data_register data);
+
+/**
+ * dmub_srv_wait_for_inbox0_ack() - wait for DMUB to ACK INBOX0 command
+ * @dmub: the dmub service
+ * @timeout_us: the maximum number of microseconds to wait
+ *
+ * Wait for DMUB to ACK the INBOX0 message
+ *
+ * Return:
+ *   DMUB_STATUS_OK - success
+ *   DMUB_STATUS_INVALID - hw_init false or hw function does not exist
+ *   DMUB_STATUS_TIMEOUT - wait for ack timed out
+ */
+enum dmub_status dmub_srv_wait_for_inbox0_ack(struct dmub_srv *dmub, uint32_t timeout_us);
+
+/**
+ * dmub_srv_wait_for_inbox0_ack() - clear ACK register for INBOX0
+ * @dmub: the dmub service
+ *
+ * Clear ACK register for INBOX0
+ *
+ * Return:
+ *   DMUB_STATUS_OK - success
+ *   DMUB_STATUS_INVALID - hw_init false or hw function does not exist
+ */
+enum dmub_status dmub_srv_clear_inbox0_ack(struct dmub_srv *dmub);
+
 #if defined(__cplusplus)
 }
 #endif

drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c

@@ -842,3 +842,38 @@ bool dmub_srv_should_detect(struct dmub_srv *dmub)
 
 	return dmub->hw_funcs.should_detect(dmub);
 }
+
+enum dmub_status dmub_srv_clear_inbox0_ack(struct dmub_srv *dmub)
+{
+	if (!dmub->hw_init || dmub->hw_funcs.clear_inbox0_ack_register)
+		return DMUB_STATUS_INVALID;
+
+	dmub->hw_funcs.clear_inbox0_ack_register(dmub);
+	return DMUB_STATUS_OK;
+}
+
+enum dmub_status dmub_srv_wait_for_inbox0_ack(struct dmub_srv *dmub, uint32_t timeout_us)
+{
+	uint32_t i = 0;
+	uint32_t ack = 0;
+
+	if (!dmub->hw_init || !dmub->hw_funcs.read_inbox0_ack_register)
+		return DMUB_STATUS_INVALID;
+
+	for (i = 0; i <= timeout_us; i++) {
+		ack = dmub->hw_funcs.read_inbox0_ack_register(dmub);
+		if (ack)
+			return DMUB_STATUS_OK;
+	}
+	return DMUB_STATUS_TIMEOUT;
+}
+
+enum dmub_status dmub_srv_send_inbox0_cmd(struct dmub_srv *dmub,
+		union dmub_inbox0_data_register data)
+{
+	if (!dmub->hw_init || dmub->hw_funcs.send_inbox0_cmd)
+		return DMUB_STATUS_INVALID;
+
+	dmub->hw_funcs.send_inbox0_cmd(dmub, data);
+	return DMUB_STATUS_OK;
+}