From 88a03c8d0148d7fc90fe73b0a91b480a1329aab2 Mon Sep 17 00:00:00 2001
From: Matthias Ringwald <matthias@ringwald.ch>
Date: Thu, 13 Aug 2020 19:41:48 +0200
Subject: [PATCH] gap: request role change for classic connection via
 `gap_request_role`

---
 CHANGELOG.md |  2 +-
 src/gap.h    | 11 ++++++++++-
 src/hci.c    | 19 +++++++++++++++++--
 src/hci.h    |  5 ++++-
 4 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 956750bc6..0f1e5d199 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,7 +18,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Added
 - `btstack_run_loop_base`: added `btstack_run_loop_base_dump_timer`
-
+- GAP: request role change for classic connection via `gap_request_role`
 ### Changed
 
 
diff --git a/src/gap.h b/src/gap.h
index 8c3e2848a..ed92e5bf9 100644
--- a/src/gap.h
+++ b/src/gap.h
@@ -139,6 +139,15 @@ hci_role_t gap_get_role(hci_con_handle_t connection_handle);
 
 // Classic
 
+/**
+ * @brief Request role switch
+ * @note this only requests the role switch. A HCI_EVENT_ROLE_CHANGE is emitted and its status field will indicate if the switch was succesful
+ * @param addr
+ * @param hci_role_t HCI_ROLE_MASTER / HCI_ROLE_SLAVE
+ * @result status
+ */
+uint8_t gap_request_role(bd_addr_t addr, hci_role_t role);
+
 /** 
  * @brief Sets local name.
  * @note has to be done before stack starts up
@@ -695,7 +704,7 @@ void gap_le_get_own_address(uint8_t * addr_type, bd_addr_t addr);
 
 
 /**
- * @brief Get state of connection re-encryptiong for bonded devices when in central role
+ * @brief Get state of connection re-encryption for bonded devices when in central role
  * @note used by gatt_client and att_server to wait for re-encryption
  * @param con_handle
  * @return 1 if security setup is active
diff --git a/src/hci.c b/src/hci.c
index e2f632acb..6ece4d24a 100644
--- a/src/hci.c
+++ b/src/hci.c
@@ -201,6 +201,7 @@ static hci_connection_t * create_connection_for_bd_addr_and_type(bd_addr_t addr,
     conn->bonding_flags = 0;
     conn->requested_security_level = LEVEL_0;
 #ifdef ENABLE_CLASSIC
+    conn->request_role = HCI_ROLE_INVALID;
     btstack_run_loop_set_timer_handler(&conn->timeout, hci_connection_timeout_handler);
     btstack_run_loop_set_timer_context(&conn->timeout, conn);
     hci_connection_timestamp(conn);
@@ -3737,7 +3738,7 @@ static bool hci_run_general_gap_le(void){
 }
 #endif
 
-static bool hci_run_general_pending_commmands(void){
+static bool hci_run_general_pending_commands(void){
     btstack_linked_item_t * it;
     for (it = (btstack_linked_item_t *) hci_stack->connections; it != NULL; it = it->next){
         hci_connection_t * connection = (hci_connection_t *) it;
@@ -3960,6 +3961,13 @@ static bool hci_run_general_pending_commmands(void){
                 hci_send_cmd(&hci_sniff_mode, connection->con_handle, connection->sniff_max_interval, sniff_min_interval, connection->sniff_attempt, connection->sniff_timeout);
                 return true;
         }
+
+        if (connection->request_role != HCI_ROLE_INVALID){
+            hci_role_t  role = connection->request_role;
+            connection->request_role = HCI_ROLE_INVALID;
+            hci_send_cmd(&hci_switch_role_command, connection->address, role);
+            return true;
+        }
 #endif
 
 #ifdef ENABLE_BLE
@@ -4030,7 +4038,7 @@ static void hci_run(void){
 #endif
 
     // send pending HCI commands
-    done = hci_run_general_pending_commmands();
+    done = hci_run_general_pending_commands();
     if (done) return;
 
     // stack state sub statemachines
@@ -5178,6 +5186,13 @@ hci_role_t gap_get_role(hci_con_handle_t connection_handle){
 }
 
 
+uint8_t gap_request_role(bd_addr_t addr, hci_role_t role){
+    hci_connection_t * conn = hci_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL);
+    if (!conn) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER;
+    conn->request_role = role;
+    hci_run();
+}
+
 #ifdef ENABLE_BLE
 
 uint8_t gap_le_set_phy(hci_con_handle_t connection_handle, uint8_t all_phys, uint8_t tx_phys, uint8_t rx_phys, uint8_t phy_options){
diff --git a/src/hci.h b/src/hci.h
index 90c859026..d64aaf8cb 100644
--- a/src/hci.h
+++ b/src/hci.h
@@ -530,7 +530,10 @@ typedef struct {
 
     // generate sco can send now based on received packets, using timeout below
     uint8_t  sco_tx_ready;
-    
+
+    // request role switch
+    hci_role_t request_role;
+
     btstack_timer_source_t timeout_sco;
 #endif /* ENABLE_CLASSIC */