From 47181045ae9215f49690e10089ba60e5edd64fbd Mon Sep 17 00:00:00 2001
From: Matthias Ringwald <matthias@ringwald.ch>
Date: Thu, 1 Feb 2018 15:17:03 +0100
Subject: [PATCH] gatt_client: add
 gatt_client_request_can_write_without_response_event()

---
 src/ble/gatt_client.c | 23 ++++++++++++++++++++++-
 src/ble/gatt_client.h | 14 +++++++++++---
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/src/ble/gatt_client.c b/src/ble/gatt_client.c
index 93167bf3f..661e58702 100644
--- a/src/ble/gatt_client.c
+++ b/src/ble/gatt_client.c
@@ -998,10 +998,22 @@ static int gatt_client_run_for_peripheral( gatt_client_t * peripheral){
             return 1;
         }
 #endif
-
         default:
             break;
     }
+
+    // requested can send snow?
+    if (peripheral->write_without_response_callback){
+        btstack_packet_handler_t packet_handler = peripheral->write_without_response_callback;
+        peripheral->write_without_response_callback = NULL;
+        uint8_t event[4];
+        event[0] = GATT_EVENT_CAN_WRITE_WITHOUT_RESPONSE;
+        event[1] = sizeof(event) - 2;
+        little_endian_store_16(event, 2, peripheral->con_handle);
+        packet_handler(HCI_EVENT_PACKET, peripheral->con_handle, event, sizeof(event));
+        return 1; // to trigger requeueing (even if higher layer didn't sent)
+    }
+
     return 0;
 }
 
@@ -1915,3 +1927,12 @@ void gatt_client_send_mtu_negotiation(btstack_packet_handler_t callback, hci_con
         gatt_client_run();
     }
 }
+
+uint8_t gatt_client_request_can_write_without_response_event(btstack_packet_handler_t callback, hci_con_handle_t con_handle){
+    gatt_client_t * context = provide_context_for_conn_handle(con_handle);
+    if (!context) return BTSTACK_MEMORY_ALLOC_FAILED;
+    if (context->write_without_response_callback) return GATT_CLIENT_IN_WRONG_STATE;
+    context->write_without_response_callback = callback;
+    att_dispatch_client_request_can_send_now_event(context->con_handle);
+    return 0;
+}
diff --git a/src/ble/gatt_client.h b/src/ble/gatt_client.h
index 654309773..ff201699b 100644
--- a/src/ble/gatt_client.h
+++ b/src/ble/gatt_client.h
@@ -138,6 +138,9 @@ typedef struct gatt_client{
     // user callback 
     btstack_packet_handler_t callback;
     
+    // can write without response callback
+    btstack_packet_handler_t write_without_response_callback;
+
     hci_con_handle_t con_handle;
     
     uint8_t   address_type;
@@ -358,6 +361,14 @@ void gatt_client_listen_for_characteristic_value_updates(gatt_client_notificatio
  */
 void gatt_client_stop_listening_for_characteristic_value_updates(gatt_client_notification_t * notification);
 
+/**
+ * @brief Requests GATT_EVENT_CAN_WRITE_WITHOUT_RESPONSE that guarantees a single successful gatt_client_write_value_of_characteristic_without_response
+ * @param packet_handler
+ * @param con_handle
+ * @returns status
+ */
+uint8_t gatt_client_request_can_write_without_response_event(btstack_packet_handler_t callback, hci_con_handle_t con_handle);
+
 /**
  * @brief -> gatt complete event
  */
@@ -381,9 +392,6 @@ void gatt_client_deserialize_service(const uint8_t *packet, int offset, gatt_cli
 void gatt_client_deserialize_characteristic(const uint8_t * packet, int offset, gatt_client_characteristic_t * characteristic);
 void gatt_client_deserialize_characteristic_descriptor(const uint8_t * packet, int offset, gatt_client_characteristic_descriptor_t * descriptor);
 
-// only used for testing
-void gatt_client_pts_suppress_mtu_exchange(void);
-
 #if defined __cplusplus
 }
 #endif