sntp/lwip: Add some modes for time synchronization

Closes: IDF-236
Closes: https://github.com/espressif/esp-idf/pull/1668
Closes: https://github.com/espressif/esp-idf/pull/4103

components/lwip/CMakeLists.txt

@@ -1,5 +1,6 @@
 set(COMPONENT_ADD_INCLUDEDIRS
     include/apps
+    include/apps/sntp
     lwip/src/include
     port/esp32/include
     port/esp32/include/arch
@@ -9,6 +10,7 @@ set(COMPONENT_ADD_INCLUDEDIRS
 set(COMPONENT_SRCS "apps/dhcpserver/dhcpserver.c"
                    "apps/ping/esp_ping.c"
                    "apps/ping/ping.c"
+                   "apps/sntp/sntp.c"
                    "lwip/src/api/api_lib.c"
                    "lwip/src/api/api_msg.c"
                    "lwip/src/api/err.c"

components/lwip/apps/sntp/sntp.c

@@ -0,0 +1,93 @@
+// Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+#include <sys/time.h>
+#include "esp_log.h"
+#include "sntp.h"
+
+static const char *TAG = "sntp";
+
+static volatile sntp_sync_mode_t sntp_sync_mode = SNTP_SYNC_MODE_IMMED;
+static volatile sntp_sync_status_t sntp_sync_status = SNTP_SYNC_STATUS_RESET;
+static sntp_sync_time_cb_t time_sync_notification_cb = NULL;
+
+inline void sntp_set_sync_status(sntp_sync_status_t sync_status)
+{
+    sntp_sync_status = sync_status;
+}
+
+void __attribute__((weak)) sntp_sync_time(struct timeval *tv)
+{
+    if (sntp_sync_mode == SNTP_SYNC_MODE_IMMED) {
+        settimeofday(tv, NULL);
+        sntp_set_sync_status(SNTP_SYNC_STATUS_COMPLETED);
+    } else if (sntp_sync_mode == SNTP_SYNC_MODE_SMOOTH) {
+        struct timeval tv_now;
+        gettimeofday(&tv_now, NULL);
+        int64_t cpu_time = (int64_t)tv_now.tv_sec * 1000000L + (int64_t)tv_now.tv_usec;
+        int64_t sntp_time = (int64_t)tv->tv_sec * 1000000L + (int64_t)tv->tv_usec;
+        int64_t delta = sntp_time - cpu_time;
+        struct timeval tv_delta = { .tv_sec = delta / 1000000L, .tv_usec = delta % 1000000L };
+        if (adjtime(&tv_delta, NULL) == -1) {
+            ESP_LOGD(TAG, "Function adjtime don't update time because the error is very big");
+            settimeofday(tv, NULL);
+            ESP_LOGD(TAG, "Time was synchronized through settimeofday");
+            sntp_set_sync_status(SNTP_SYNC_STATUS_COMPLETED);
+        } else {
+            sntp_set_sync_status(SNTP_SYNC_STATUS_IN_PROGRESS);
+        }
+    }
+    if (time_sync_notification_cb) {
+        time_sync_notification_cb(tv);
+    }
+}
+
+void sntp_set_sync_mode(sntp_sync_mode_t sync_mode)
+{
+    sntp_sync_mode = sync_mode;
+}
+
+sntp_sync_mode_t sntp_get_sync_mode(void)
+{
+    return sntp_sync_mode;
+}
+
+// set a callback function for time synchronization notification
+void sntp_set_time_sync_notification_cb(sntp_sync_time_cb_t callback)
+{
+    time_sync_notification_cb = callback;
+}
+
+sntp_sync_status_t sntp_get_sync_status(void)
+{
+    sntp_sync_status_t ret_sync_status = SNTP_SYNC_STATUS_RESET;
+    sntp_sync_status_t sync_status = sntp_sync_status;
+    if (sync_status == SNTP_SYNC_STATUS_COMPLETED) {
+        sntp_set_sync_status(SNTP_SYNC_STATUS_RESET);
+        ret_sync_status = SNTP_SYNC_STATUS_COMPLETED;
+    } else if (sync_status == SNTP_SYNC_STATUS_IN_PROGRESS) {
+        struct timeval outdelta;
+        adjtime(NULL, &outdelta);
+        if (outdelta.tv_sec == 0 && outdelta.tv_usec == 0) {
+            sntp_set_sync_status(SNTP_SYNC_STATUS_RESET);
+            ret_sync_status = SNTP_SYNC_STATUS_COMPLETED;
+        } else {
+            ret_sync_status = SNTP_SYNC_STATUS_IN_PROGRESS;
+        }
+    }
+    return ret_sync_status;
+}

components/lwip/component.mk

@@ -5,6 +5,7 @@ COMPONENT_SUBMODULES += lwip
 
 COMPONENT_ADD_INCLUDEDIRS := \
 	include/apps \
+	include/apps/sntp \
 	lwip/src/include \
 	port/esp32/include \
 	port/esp32/include/arch \
@@ -13,6 +14,7 @@ COMPONENT_ADD_INCLUDEDIRS := \
 COMPONENT_SRCDIRS := \
 	apps/dhcpserver \
 	apps/ping \
+	apps/sntp \
 	lwip/src/api \
 	lwip/src/apps/sntp \
 	lwip/src/core \

components/lwip/include/apps/esp_sntp.h

@@ -0,0 +1,22 @@
+// Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef __ESP_SNTP_H__
+#define __ESP_SNTP_H__
+
+#include "lwip/err.h"
+#include "lwip/apps/sntp.h"
+#include "sntp.h"
+
+#endif // __ESP_SNTP_H__

components/lwip/include/apps/sntp/sntp.h

@@ -0,0 +1,119 @@
+// Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef __SNTP_H__
+#define __SNTP_H__
+
+/*
+ * The time update takes place in the sntp_sync_time() function.
+ * The user has the ability to redefine this function in order
+ * to re-define its functionality. This function has two time update modes,
+ * which can be set via the sntp_set_sync_mode() function.
+ * Two modes are available:
+ * - the first is an immediate update when receiving time from the sntp server,
+ * - the second is a smooth time update (if the time error is no more than 35 minutes,
+ *   and an immediate update if the error is more than 35 minutes).
+ *
+ * To receive notification of time synchronization,
+ * you can use the callback function or get the synchronization status
+ * via the sntp_get_sync_status() function.
+ *
+ * To determine the time synchronization time on the device, you can use:
+ * 1) sntp_set_time_sync_notification_cb() function to set the callback function,
+ *    which is convenient to use to receive notification of the update time.
+ * 2) sntp_get_sync_status() function for getting time synchronization status.
+ *    After the time synchronization is completed, the status will be
+ *    SNTP_SYNC_STATUS_COMPLETED, after, it will be reseted to SNTP_SYNC_STATUS_RESET
+ *    to wait for the next sync cycle.
+ */
+
+/// SNTP time update mode
+typedef enum {
+    SNTP_SYNC_MODE_IMMED,   /*!< Update system time immediately when receiving a response from the SNTP server. */
+    SNTP_SYNC_MODE_SMOOTH,  /*!< Smooth time updating. Time error is gradually reduced using adjtime function. If the difference between SNTP response time and system time is large (more than 35 minutes) then update immediately. */
+} sntp_sync_mode_t;
+
+/// SNTP sync status
+typedef enum {
+    SNTP_SYNC_STATUS_RESET,         // Reset status.
+    SNTP_SYNC_STATUS_COMPLETED,     // Time is synchronized.
+    SNTP_SYNC_STATUS_IN_PROGRESS,   // Smooth time sync in progress.
+} sntp_sync_status_t;
+
+/**
+ * @brief SNTP callback function for notifying about time sync event
+ *
+ * @param tv Time received from SNTP server.
+ */
+typedef void (*sntp_sync_time_cb_t) (struct timeval *tv);
+
+/**
+ * @brief This function updates the system time.
+ *
+ * This is a weak-linked function. It is possible to replace all SNTP update functionality
+ * by placing a sntp_sync_time() function in the app firmware source.
+ * If the default implementation is used, calling sntp_set_sync_mode() allows
+ * the time synchronization mode to be changed to instant or smooth.
+ * If a callback function is registered via sntp_set_time_sync_notification_cb(),
+ * it will be called following time synchronization.
+ *
+ * @param tv Time received from SNTP server.
+ */
+void sntp_sync_time(struct timeval *tv);
+
+/**
+ * @brief Set the sync mode
+ *
+ * Allowable two mode: SNTP_SYNC_MODE_IMMED and SNTP_SYNC_MODE_SMOOTH.
+ * @param sync_mode Sync mode.
+ */
+void sntp_set_sync_mode(sntp_sync_mode_t sync_mode);
+
+/**
+ * @brief Get set sync mode
+ *
+ * @return  SNTP_SYNC_MODE_IMMED: Update time immediately.
+ *          SNTP_SYNC_MODE_SMOOTH: Smooth time updating.
+ */
+sntp_sync_mode_t sntp_get_sync_mode(void);
+
+/**
+ * @brief Get status of time sync
+ *
+ * After the update is completed, the status will be returned as SNTP_SYNC_STATUS_COMPLETED.
+ * After that, the status will be reset to SNTP_SYNC_STATUS_RESET.
+ * If the update operation is not completed yet, the status will be SNTP_SYNC_STATUS_RESET.
+ * If a smooth mode was chosen and the synchronization is still continuing (adjtime works), then it will be SNTP_SYNC_STATUS_IN_PROGRESS.
+ *
+ * @return  SNTP_SYNC_STATUS_RESET: Reset status.
+ *          SNTP_SYNC_STATUS_COMPLETED: Time is synchronized.
+ *          SNTP_SYNC_STATUS_IN_PROGRESS: Smooth time sync in progress.
+ */
+sntp_sync_status_t sntp_get_sync_status(void);
+
+/**
+ * @brief Set status of time sync
+ *
+ * @param sync_status status of time sync (see sntp_sync_status_t)
+ */
+void sntp_set_sync_status(sntp_sync_status_t sync_status);
+
+/**
+ * @brief Set a callback function for time synchronization notification
+ *
+ * @param callback a callback function
+ */
+void sntp_set_time_sync_notification_cb(sntp_sync_time_cb_t callback);
+
+#endif // __SNTP_H__

components/lwip/include_compat/apps/sntp/sntp.h

@@ -1,3 +1,3 @@
 #pragma once
-#warning "This header file is deprecated, please include lwip/apps/sntp.h instead."
-#include "lwip/apps/sntp.h"
+#warning "This header file is deprecated, please include esp_sntp.h instead."
+#include "esp_sntp.h"

components/lwip/port/esp32/include/lwipopts.h

@@ -43,7 +43,7 @@
 #include "esp_task.h"
 #include "esp_system.h"
 #include "sdkconfig.h"
-
+#include "sntp.h"
 #include "netif/dhcp_state.h"
 
 /* Enable all Espressif-only options */
@@ -836,7 +836,7 @@ enum {
 #define SNTP_SET_SYSTEM_TIME_US(sec, us)  \
     do { \
         struct timeval tv = { .tv_sec = sec, .tv_usec = us }; \
-        settimeofday(&tv, NULL); \
+        sntp_sync_time(&tv); \
     } while (0);
 
 #define SNTP_GET_SYSTEM_TIME(sec, us) \
@@ -845,6 +845,7 @@ enum {
         gettimeofday(&tv, NULL); \
         (sec) = tv.tv_sec;  \
         (us) = tv.tv_usec; \
+        sntp_set_sync_status(SNTP_SYNC_STATUS_RESET); \
     } while (0);
 
 #define SOC_SEND_LOG //printf