From c50d44e66e6f2e363a08dc9e197e7a1389213b24 Mon Sep 17 00:00:00 2001
From: Konstantin Kondrashov <konstantin@espressif.com>
Date: Mon, 17 Jun 2019 15:44:25 +0800
Subject: [PATCH] sntp/lwip: Add SNTP_UPDATE_DELAY option in Kconfig

Closes: https://github.com/espressif/esp-idf/issues/2277
Closes: IDFGH-337
---
 components/lwip/Kconfig                       | 31 +++++++++++++------
 components/lwip/port/esp32/include/lwipopts.h | 10 ++++++
 2 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/components/lwip/Kconfig b/components/lwip/Kconfig
index 025305d95..34557400a 100644
--- a/components/lwip/Kconfig
+++ b/components/lwip/Kconfig
@@ -74,15 +74,6 @@ menu "LWIP"
         help
             Enabling this option allows checking for available data on a netconn.
 
-    config LWIP_DHCP_MAX_NTP_SERVERS
-        int "Maximum number of NTP servers"
-        default 1
-        range 1 16
-        help
-            Set maximum number of NTP servers used by LwIP SNTP module.
-            First argument of sntp_setserver/sntp_setservername functions
-            is limited to this value.
-
     config LWIP_IP_FRAG
         bool "Enable fragment outgoing IP packets"
         default n
@@ -560,4 +551,26 @@ menu "LWIP"
 
     endmenu  # LWIP RAW API
 
+    menu "SNTP"
+
+        config LWIP_DHCP_MAX_NTP_SERVERS
+            int "Maximum number of NTP servers"
+            default 1
+            range 1 16
+            help
+                Set maximum number of NTP servers used by LwIP SNTP module.
+                First argument of sntp_setserver/sntp_setservername functions
+                is limited to this value.
+
+        config LWIP_SNTP_UPDATE_DELAY
+            int "Request interval to update time (ms)"
+            range 15000 4294967295
+            default 3600000
+            help
+                This option allows you to set the time update period via SNTP.
+                Default is 1 hour. Must not be below 15 seconds by specification.
+                (SNTPv4 RFC 4330 enforces a minimum update time of 15 seconds).
+
+    endmenu # SNTP
+
 endmenu
diff --git a/components/lwip/port/esp32/include/lwipopts.h b/components/lwip/port/esp32/include/lwipopts.h
index c22046e0d..de0ee9c31 100644
--- a/components/lwip/port/esp32/include/lwipopts.h
+++ b/components/lwip/port/esp32/include/lwipopts.h
@@ -833,6 +833,16 @@ enum {
 #define LWIP_DHCP_MAX_NTP_SERVERS       CONFIG_LWIP_DHCP_MAX_NTP_SERVERS
 #define LWIP_TIMEVAL_PRIVATE            0
 
+/*
+   --------------------------------------
+   ------------ SNTP options ------------
+   --------------------------------------
+*/
+/*
+ * SNTP update delay - in milliseconds
+ */
+#define SNTP_UPDATE_DELAY              CONFIG_LWIP_SNTP_UPDATE_DELAY
+
 #define SNTP_SET_SYSTEM_TIME_US(sec, us)  \
     do { \
         struct timeval tv = { .tv_sec = sec, .tv_usec = us }; \