greybus: svc: implement connection_quiescing call

Implement Greybus remote call to connection_quiescing operation. This
operation disables flow contorl for the connection and resets associated
attributes.

Testing done: tested along with required NuttX firmware changes, booted
EVT2, inserted module, removed module, inserted module. Verified module
was functioning as expected.
Signed-off-by: Jeffrey Carlyle <jcarlyle@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/greybus_protocols.h

@@ -904,6 +904,7 @@ struct gb_spi_transfer_response {
 #define GB_SVC_TYPE_TIMESYNC_WAKE_PINS_ACQUIRE	0x18
 #define GB_SVC_TYPE_TIMESYNC_WAKE_PINS_RELEASE	0x19
 #define GB_SVC_TYPE_TIMESYNC_PING		0x1a
+#define GB_SVC_TYPE_CONN_QUIESCING		0x1e
 #define GB_SVC_TYPE_MODULE_INSERTED		0x1f
 #define GB_SVC_TYPE_MODULE_REMOVED		0x20
 #define GB_SVC_TYPE_INTF_VSYS_ENABLE		0x21
@@ -1215,6 +1216,17 @@ struct gb_svc_intf_mailbox_event_request {
 } __packed;
 /* intf_mailbox_event response has no payload */
 
+struct gb_svc_conn_quiescing_request {
+	__u8	intf1_id;
+	__le16	cport1_id;
+	__u8	intf2_id;
+	__le16	cport2_id;
+} __packed;
+
+struct gb_svc_conn_quiescing_response {
+	__u8	status;
+} __packed;
+
 
 /* RAW */
 

drivers/staging/greybus/svc.c

@@ -441,10 +441,31 @@ EXPORT_SYMBOL_GPL(gb_svc_connection_create);
 void gb_svc_connection_quiescing(struct gb_svc *svc, u8 intf1_id, u16 cport1_id,
 					u8 intf2_id, u16 cport2_id)
 {
-	/* FIXME: implement */
+	struct gb_svc_conn_quiescing_request request;
+	struct gb_svc_conn_quiescing_response response;
+	int ret;
 
 	dev_dbg(&svc->dev, "%s - (%u:%u %u:%u)\n", __func__,
 				intf1_id, cport1_id, intf2_id, cport2_id);
+
+	request.intf1_id = intf1_id;
+	request.cport1_id = cpu_to_le16(cport1_id);
+	request.intf2_id = intf2_id;
+	request.cport2_id = cpu_to_le16(cport2_id);
+
+	ret = gb_operation_sync(svc->connection, GB_SVC_TYPE_CONN_QUIESCING,
+				 &request, sizeof(request),
+				 &response, sizeof(response));
+	if (ret < 0)
+		return;
+	if (response.status != GB_SVC_OP_SUCCESS) {
+		dev_err(&svc->dev, "quiescing connection failed (%u:%u %u:%u): %u\n",
+				intf1_id, cport1_id, intf2_id, cport2_id,
+				response.status);
+		return;
+	}
+
+	return;
 }
 EXPORT_SYMBOL_GPL(gb_svc_connection_quiescing);