SoftAP support for LWiFi library (#67)

This feature adds LWiFi.softAP() method that allows user to switch LinkIt 7697 into a simple Wi-Fi access point. Calling LWiFi.softAPdisconnect() or LWiFi.begin() to switch back to STA mode, which connects to other access points.

To do so:

* SoftAP implementation using `AP_ONLY` mode in LinkIt SDK.

* Patch `middelware/MTK/dhcpd` of LinkIT SDK to prevent include path collision. In Arduino projects, we need to prevent adding "lwip/inc/lwip" directly into compiler include pathes. Failing to do so would cause confusions between Arduino "Udp.h" and lwip "lwip/udp.h". As a result, we change the include path in `dhcpd.h` to  `lwip/ipv4.h"

* Clean up Wi-Fi initialization routines. BLE, STA and AP all initializes (`wifi_init()`) when necessary, resulting in redundant code. We refactor the Wi-Fi initializtion routines into a common function `init_gloabal_connsys` in `variant.h`. Also clean up some formatting issues and add some more documentation to softAP APIs. Since we always initialize Wi-Fi in STA mode, we have to use `wifi_config_*` APIs to update SoftAP settings, instead of relying on `wifi_init` and `lwip_tcpip_init`.

* Add example codes for `softAP()` and `softAPdisconnect()` usages.

Author: pablosun

middleware/MTK/dhcpd/inc/dhcpd.h

@@ -0,0 +1,195 @@
+/* Copyright Statement:
+ *
+ * (C) 2005-2016  MediaTek Inc. All rights reserved.
+ *
+ * This software/firmware and related documentation ("MediaTek Software") are
+ * protected under relevant copyright laws. The information contained herein
+ * is confidential and proprietary to MediaTek Inc. ("MediaTek") and/or its licensors.
+ * Without the prior written permission of MediaTek and/or its licensors,
+ * any reproduction, modification, use or disclosure of MediaTek Software,
+ * and information contained herein, in whole or in part, shall be strictly prohibited.
+ * You may only use, reproduce, modify, or distribute (as applicable) MediaTek Software
+ * if you have agreed to and been bound by the applicable license agreement with
+ * MediaTek ("License Agreement") and been granted explicit permission to do so within
+ * the License Agreement ("Permitted User").  If you are not a Permitted User,
+ * please cease any access or use of MediaTek Software immediately.
+ * BY OPENING THIS FILE, RECEIVER HEREBY UNEQUIVOCALLY ACKNOWLEDGES AND AGREES
+ * THAT MEDIATEK SOFTWARE RECEIVED FROM MEDIATEK AND/OR ITS REPRESENTATIVES
+ * ARE PROVIDED TO RECEIVER ON AN "AS-IS" BASIS ONLY. MEDIATEK EXPRESSLY DISCLAIMS ANY AND ALL
+ * WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NONINFRINGEMENT.
+ * NEITHER DOES MEDIATEK PROVIDE ANY WARRANTY WHATSOEVER WITH RESPECT TO THE
+ * SOFTWARE OF ANY THIRD PARTY WHICH MAY BE USED BY, INCORPORATED IN, OR
+ * SUPPLIED WITH MEDIATEK SOFTWARE, AND RECEIVER AGREES TO LOOK ONLY TO SUCH
+ * THIRD PARTY FOR ANY WARRANTY CLAIM RELATING THERETO. RECEIVER EXPRESSLY ACKNOWLEDGES
+ * THAT IT IS RECEIVER'S SOLE RESPONSIBILITY TO OBTAIN FROM ANY THIRD PARTY ALL PROPER LICENSES
+ * CONTAINED IN MEDIATEK SOFTWARE. MEDIATEK SHALL ALSO NOT BE RESPONSIBLE FOR ANY MEDIATEK
+ * SOFTWARE RELEASES MADE TO RECEIVER'S SPECIFICATION OR TO CONFORM TO A PARTICULAR
+ * STANDARD OR OPEN FORUM. RECEIVER'S SOLE AND EXCLUSIVE REMEDY AND MEDIATEK'S ENTIRE AND
+ * CUMULATIVE LIABILITY WITH RESPECT TO MEDIATEK SOFTWARE RELEASED HEREUNDER WILL BE,
+ * AT MEDIATEK'S OPTION, TO REVISE OR REPLACE MEDIATEK SOFTWARE AT ISSUE,
+ * OR REFUND ANY SOFTWARE LICENSE FEES OR SERVICE CHARGE PAID BY RECEIVER TO
+ * MEDIATEK FOR SUCH MEDIATEK SOFTWARE AT ISSUE.
+ */
+
+#ifndef __DHCPD_H__
+#define __DHCPD_H__
+#include "lwip/ip4_addr.h"
+#include "syslog.h"
+
+
+/**
+ * @addtogroup DHCPD
+ * @{
+ * This section introduces the DHCP daemon (DHCPD) APIs including details on how to use this module, structures and functions.
+ * It's a simple DHCP daemon to operate in soft AP mode for assigning IP addresses to connected Wi-Fi station nodes.
+ *
+ * @section DHCPD_Terms_Chapter Terms and acronyms
+ *
+ * |Terms                         |Details                                                                 |
+ * |------------------------------|------------------------------------------------------------------------|
+ * |\b DHCP                       | Dynamic Host Configuration Protocol. |
+ * |\b Wi-Fi                      | Wi-Fi is a local area wireless computer networking technology, https://en.wikipedia.org/wiki/Wi-Fi |
+ *
+ * @section DHCPD_Usage_Chapter How to use this module
+ *
+ * - Step1: Set DHCPD parameters.
+ *              If you want to use all default DHCPD parameters (DHPCD_DEFAULT_X, such as DHPCD_DEFAULT_SERVER_IP),
+ *              skip this step.
+ * - Step2: Call #dhcpd_start() to start the service.
+ *              If you want to use all default DHCPD parameters (DHPCD_DEFAULT_X, such as DHPCD_DEFAULT_SERVER_IP),
+ *              just call #dhcpd_start(NULL).
+ *  - Sample code:
+ *     @code
+ *        xTaskHandle dhcpd_task;
+ *        int32_t process_softap(void)
+ *        {
+ *            LOG_I(common, "Now start DHCPD:");
+ *            dhcpd_settings_t dhcpd_settings;
+ *
+ *            memset(&dhcpd_settings, 0, sizeof(dhcpd_settings_t));
+ *            strncpy(dhcpd_settings.dhcpd_server_address, "10.10.10.2" , IP4ADDR_STRLEN_MAX - 1);
+ *            strncpy(dhcpd_settings.dhcpd_gateway, "10.10.10.1" , IP4ADDR_STRLEN_MAX - 1);
+ *            strncpy(dhcpd_settings.dhcpd_netmask, "255.255.255.0" , IP4ADDR_STRLEN_MAX - 1);
+ *            strncpy(dhcpd_settings.dhcpd_primary_dns, "8.8.8.8" , IP4ADDR_STRLEN_MAX - 1);
+ *            strncpy(dhcpd_settings.dhcpd_secondary_dns, "8.8.4.4" , IP4ADDR_STRLEN_MAX - 1);
+ *            strncpy(dhcpd_settings.dhcpd_ip_pool_start, "10.10.10.3" , IP4ADDR_STRLEN_MAX - 1);
+ *            strncpy(dhcpd_settings.dhcpd_ip_pool_end, "10.10.10.11" , IP4ADDR_STRLEN_MAX - 1);
+ *
+ *            dhcpd_start(&dhcpd_settings);
+ *
+ *            return 0;
+ *        }
+ *
+ *     @endcode
+ */
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/** @defgroup dhcpd_define Define
+  * @{
+  */
+
+
+/** @brief  This macro enables the feature of saving the client configuration when AP is keeping power on.
+  * Client configuration will not be stored when AP is power off.
+  */
+#define DHCPD_SAVE_CLIENT_CONFIG_ON_LINE
+
+
+/** @brief This macro defines default IP lease time in seconds.
+ */
+#define DHCPD_DEFAULT_LEASE_TIME (64800)
+
+
+/** @brief This macro defines default server IP for AP.
+ */
+#define DHPCD_DEFAULT_SERVER_IP            ("10.10.10.1")
+
+
+/** @brief This macro defines default gateway IP for AP.
+ */
+#define DHPCD_DEFAULT_GATEWAY              ("10.10.10.1")
+
+
+/** @brief This macro defines default netmask for AP.
+ */
+#define DHPCD_DEFAULT_NETMASK              ("255.255.255.0")
+
+
+/** @brief This macro defines default primary DNS IP for AP.
+ */
+#define DHPCD_DEFAULT_PRIMARY_DNS          ("8.8.8.8")
+
+
+/** @brief This macro defines default secondary DNS IP for AP.
+ */
+#define DHPCD_DEFAULT_SECONDARY_DNS        ("8.8.4.4")
+
+
+/** @brief This macro defines default starting IP for IP pool.
+ */
+#define DHPCD_DEFAULT_IP_POOL_START        ("10.10.10.2")
+
+
+/** @brief This macro defines default ending IP for IP pool.
+ */
+#define DHPCD_DEFAULT_IP_POOL_END          ("10.10.10.10")
+
+/**
+  * @}
+  */
+
+
+/** @defgroup dhcpd_struct Struct
+  * @{
+  */
+
+/** @brief This structure defines the DHCPD configuration structure. For more information, please refer to #dhcpd_start() */
+typedef struct
+{
+    char dhcpd_server_address[IP4ADDR_STRLEN_MAX];  /**< Specify server IP for AP. */
+    char dhcpd_gateway[IP4ADDR_STRLEN_MAX];         /**< Specify gateway IP for AP. */
+    char dhcpd_netmask[IP4ADDR_STRLEN_MAX];         /**< Specify netmask for AP. */
+    char dhcpd_primary_dns[IP4ADDR_STRLEN_MAX];     /**< Specify primary DNS IP for AP. */
+    char dhcpd_secondary_dns[IP4ADDR_STRLEN_MAX];   /**< Specify secondary DNS IP for AP. */
+    char dhcpd_ip_pool_start[IP4ADDR_STRLEN_MAX];   /**< Specify starting IP for IP pool. */
+    char dhcpd_ip_pool_end[IP4ADDR_STRLEN_MAX];     /**< Specify ending IP for IP pool. */
+} dhcpd_settings_t;
+
+/**
+  * @}
+  */
+
+
+/**
+ * @brief This function is used to start the DHCPD service. It creates a new task for the DHCPD, then returns. The DHCPD task runs until dhcpd_stop() is called.
+ * @param[in] dhcpd_settings specifies the settings for DHCPD, such as DHCP server IP, gateway, netmask, DNS and IP pool. These settings can be set individually.
+ *            If the setting is not set, default value will be used. Please beware that if both default values and customer configured value are used, they should
+ *            match to each other.
+ * @return
+ * @sa #dhcpd_stop();
+ */
+int dhcpd_start(dhcpd_settings_t *dhcpd_settings);
+
+
+/**
+ * @brief This function is used to stop the DHCPD service. It kills the DHCPD task and stops the DHCPD service immediately.
+ * @return
+ * @sa #dhcpd_start();
+ */
+void dhcpd_stop(void);
+
+/**
+ * @}
+ */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __DHCPD_H__ */

middleware/third_party/arduino/Makefile

@@ -69,6 +69,7 @@ include $(SOURCE_DIR)/middleware/MTK/bluetooth/module.mk
 
 # WiFi files
 include $(SOURCE_DIR)/middleware/MTK/wifi_service/combo/module.mk
+CXXFLAGS += -I$(SOURCE_DIR)/middleware/MTK/wifi_service/combo/inc
 
 CXXFLAGS += -fno-rtti
 

middleware/third_party/arduino/hardware/arduino/mt7697/cores/arduino/IPAddress.cpp

@@ -72,3 +72,15 @@ size_t IPAddress::printTo(Print& p) const
 	n += p.print(_address.bytes[3], DEC);
 	return n;
 }
+
+String IPAddress::toString() const {
+	String p;
+	size_t n = 0;
+	for (int i =0; i < 3; i++)
+	{
+		p += String(_address.bytes[i], DEC);
+		p += String('.');
+	}
+	p += String(_address.bytes[3], DEC);
+	return p;
+}

middleware/third_party/arduino/hardware/arduino/mt7697/cores/arduino/IPAddress.h

@@ -21,6 +21,7 @@
 #define IPAddress_h
 
 #include <stdint.h>
+#include "WString.h"
 #include "Printable.h"
 
 // A class to make it easier to handle and pass around IP addresses
@@ -60,6 +61,7 @@ class IPAddress : public Printable {
 		IPAddress& operator=(uint32_t address);
 
 		virtual size_t printTo(Print& p) const;
+		virtual String toString() const;
 
 		friend class EthernetClass;
 		friend class UDP;

middleware/third_party/arduino/hardware/arduino/mt7697/libraries/LBLE/src/utility/ard_ble.c

@@ -27,37 +27,11 @@
 #include <lwip/dns.h>
 #include <ethernetif.h>
 
-// declared in Arduino core's "variant.h"
-extern void set_wifi_ready(void);
-extern bool wifi_ready(void);
-
-static int32_t _wifi_event_handler(wifi_event_t event, uint8_t* payload, uint32_t length)
-{
-    switch(event)
-    {
-    case WIFI_EVENT_IOT_INIT_COMPLETE:
-        set_wifi_ready();
-        pr_debug("event=0x%x, payload=0x%p, length=0x%x", (unsigned int)event, payload, (unsigned int)length);
-        break;
-    }
-
-    return 1;
-}
-
 static void _connsys_workaround()
 {
-    /* Wi-Fi must be initialized for BLE start-up */
-    if(!wifi_ready())
-    {
-        wifi_connection_register_event_handler(WIFI_EVENT_IOT_INIT_COMPLETE, _wifi_event_handler);
-
-        wifi_config_t config = {0};
-        config.opmode = WIFI_MODE_STA_ONLY;
-        wifi_init(&config, NULL);
-
-        lwip_tcpip_config_t tcpip_config = {{0}, {0}, {0}, {0}, {0}, {0}};
-        lwip_tcpip_init(&tcpip_config, WIFI_MODE_STA_ONLY);
-    }
+    // Wi-Fi must be initialized for BLE start-up
+    // declared in Arduino core's "variant.h"
+    init_global_connsys();
 }
 
 /*

middleware/third_party/arduino/hardware/arduino/mt7697/libraries/LWiFi/examples/AccessPoint/AccessPoint.ino

@@ -0,0 +1,79 @@
+#include <LWiFi.h>
+#include <WiFiClient.h>
+// #include <LWebServer.h>
+
+/* Set these to your desired credentials. */
+const char *ssid = "LinkItAP";
+const char *password = "yourpassword";
+
+WiFiServer server(80);
+
+void setup() {
+    Serial.begin(115200);
+    Serial.println();
+    Serial.print("Configuring access point...");
+
+    /* You can remove the password parameter if you want the AP to be open. */
+    WiFi.softAP(ssid, password);
+    IPAddress myIP = WiFi.softAPIP();
+    Serial.println("AP ready.");
+    Serial.print("Connect to AP ");
+    Serial.print(ssid);
+    Serial.print(" and visit http://");
+    Serial.println(myIP);
+
+    Serial.print("AP MAC=");
+    Serial.println(WiFi.softAPmacAddress());
+
+    server.begin();
+}
+
+void loop() {
+    // server.handleClient();
+    // listen for incoming clients
+    WiFiClient client = server.available();
+    if (client) {
+        // an http request ends with a blank line
+        boolean currentLineIsBlank = true;
+        while (client.connected()) {
+            if (client.available()) {
+                char c = client.read();
+                Serial.write(c);
+                // if you've gotten to the end of the line (received a newline
+                // character) and the line is blank, the http request has ended,
+                // so you can send a reply
+                if (c == '\n' && currentLineIsBlank) {
+                    // send a standard http response header
+                    client.println("HTTP/1.1 200 OK");
+                    client.println("Content-Type: text/html");
+                    client.println("Connection: close");  // the connection will be closed after completion of the response
+                    client.println();
+                    client.println("<!DOCTYPE HTML>");
+                    client.println("<html>");
+                    client.println("<p>Hello from LinkIt 7697!</p>");
+                    client.println("<p>Wi-Fi SSID: ");
+                    client.print(ssid);
+                    client.println("</p>");
+                    client.print("<p>Connected STA #: ");
+                    client.print((int)WiFi.softAPgetStationNum());
+                    client.println("</p>");
+                    client.println("</html>");
+                    break;
+                }
+                if (c == '\n') {
+                    // you're starting a new line
+                    currentLineIsBlank = true;
+                } else if (c != '\r') {
+                    // you've gotten a character on the current line
+                    currentLineIsBlank = false;
+                }
+            }
+        }
+        // give the web browser time to receive the data
+        delay(300);
+
+        // close the connection:
+        client.stop();
+        Serial.println("client disonnected");
+    }
+}