esp32: Split out WLAN code from modnetwork.c to network_wlan.c.

To match network_lan.c and network_ppp.c, and make it clear what code is
specifically for WLAN support.

Also provide a configuration option MICROPY_PY_NETWORK_WLAN which can be
used to fully disable network.WLAN (it's enabled by default).
Signed-off-by: Damien George <damien@micropython.org>

ports/esp32/main/CMakeLists.txt

@@ -67,6 +67,7 @@ set(MICROPY_SOURCE_PORT
     ${PROJECT_DIR}/modnetwork.c
     ${PROJECT_DIR}/network_lan.c
     ${PROJECT_DIR}/network_ppp.c
+    ${PROJECT_DIR}/network_wlan.c
     ${PROJECT_DIR}/mpnimbleport.c
     ${PROJECT_DIR}/modsocket.c
     ${PROJECT_DIR}/modesp.c

ports/esp32/modnetwork.h

@@ -26,14 +26,39 @@
 #ifndef MICROPY_INCLUDED_ESP32_MODNETWORK_H
 #define MICROPY_INCLUDED_ESP32_MODNETWORK_H
 
+#include "esp_event.h"
+
 enum { PHY_LAN8720, PHY_IP101, PHY_RTL8201, PHY_DP83848, PHY_KSZ8041 };
 enum { ETH_INITIALIZED, ETH_STARTED, ETH_STOPPED, ETH_CONNECTED, ETH_DISCONNECTED, ETH_GOT_IP };
 
+// Cases similar to ESP8266 user_interface.h
+// Error cases are referenced from wifi_err_reason_t in ESP-IDF
+enum {
+    STAT_IDLE       = 1000,
+    STAT_CONNECTING = 1001,
+    STAT_GOT_IP     = 1010,
+};
+
+typedef struct _wlan_if_obj_t {
+    mp_obj_base_t base;
+    int if_id;
+} wlan_if_obj_t;
+
+MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(get_wlan_obj);
 MP_DECLARE_CONST_FUN_OBJ_KW(get_lan_obj);
 MP_DECLARE_CONST_FUN_OBJ_1(ppp_make_new_obj);
 MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(esp_ifconfig_obj);
 MP_DECLARE_CONST_FUN_OBJ_KW(esp_config_obj);
 
+NORETURN void esp_exceptions_helper(esp_err_t e);
+
+static inline void esp_exceptions(esp_err_t e) {
+    if (e != ESP_OK) {
+        esp_exceptions_helper(e);
+    }
+}
+
 void usocket_events_deinit(void);
+void network_wlan_event_handler(system_event_t *event);
 
 #endif

ports/esp32/mpconfigport.h

@@ -174,6 +174,9 @@
 #ifndef MICROPY_PY_MACHINE_I2S
 #define MICROPY_PY_MACHINE_I2S              (1)
 #endif
+#ifndef MICROPY_PY_NETWORK_WLAN
+#define MICROPY_PY_NETWORK_WLAN             (1)
+#endif
 #ifndef MICROPY_HW_ENABLE_SDCARD
 #define MICROPY_HW_ENABLE_SDCARD            (1)
 #endif