esp8266: Make pyb.RTC a type, and pyb.RTC() constructs an RTC object.

This is the standard way of doing things, one should construct a
peripheral object (even if it's a singleton).

See issue #1330.

esp8266/modpyb.c

@@ -172,7 +172,7 @@ STATIC const mp_map_elem_t pyb_module_globals_table[] = {
 
     { MP_OBJ_NEW_QSTR(MP_QSTR_Pin), (mp_obj_t)&pyb_pin_type },
     { MP_OBJ_NEW_QSTR(MP_QSTR_ADC), (mp_obj_t)&pyb_adc_type },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_RTC), (mp_obj_t)&pyb_rtc_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_RTC), (mp_obj_t)&pyb_rtc_type },
 };
 
 STATIC MP_DEFINE_CONST_DICT(pyb_module_globals, pyb_module_globals_table);

esp8266/modpyb.h

@@ -1,3 +1,3 @@
 extern const mp_obj_type_t pyb_pin_type;
 extern const mp_obj_type_t pyb_adc_type;
-extern const mp_obj_base_t pyb_rtc_obj;
+extern const mp_obj_type_t pyb_rtc_type;

esp8266/modpybrtc.c

@@ -33,6 +33,7 @@
 #include MICROPY_HAL_H
 #include "timeutils.h"
 #include "user_interface.h"
+#include "modpyb.h"
 
 typedef struct _pyb_rtc_obj_t {
     mp_obj_base_t base;
@@ -46,6 +47,17 @@ typedef struct _pyb_rtc_obj_t {
 #define MEM_USER_DATA_ADDR  (MEM_USER_LEN_ADDR + 1)
 #define MEM_USER_MAXLEN     (512 - (MEM_USER_DATA_ADDR - MEM_DELTA_ADDR) * 4)
 
+// singleton RTC object
+STATIC const pyb_rtc_obj_t pyb_rtc_obj = {{&pyb_rtc_type}};
+
+STATIC mp_obj_t pyb_rtc_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+    // check arguments
+    mp_arg_check_num(n_args, n_kw, 0, 0, false);
+
+    // return constant object
+    return (mp_obj_t)&pyb_rtc_obj;
+}
+
 STATIC uint64_t pyb_rtc_raw_us(uint64_t cal) {
     return system_get_rtc_time() * ((cal >> 12) * 1000 + (cal & 0xfff) / 4) / 1000;
 };
@@ -158,10 +170,9 @@ STATIC const mp_map_elem_t pyb_rtc_locals_dict_table[] = {
 };
 STATIC MP_DEFINE_CONST_DICT(pyb_rtc_locals_dict, pyb_rtc_locals_dict_table);
 
-STATIC const mp_obj_type_t pyb_rtc_type = {
+const mp_obj_type_t pyb_rtc_type = {
     { &mp_type_type },
     .name = MP_QSTR_RTC,
+    .make_new = pyb_rtc_make_new,
     .locals_dict = (mp_obj_t)&pyb_rtc_locals_dict,
 };
-
-const mp_obj_base_t pyb_rtc_obj = {&pyb_rtc_type};