esp8266: Change nativeio.I2C to use bitbangio under the hood rather than throwing an error.

esp8266/Makefile

@@ -113,7 +113,6 @@ SRC_COMMON_HAL = \
 	nativeio/AnalogIn.c \
 	nativeio/AnalogOut.c \
 	nativeio/DigitalInOut.c \
-	nativeio/I2C.c \
 	nativeio/PulseIn.c \
 	nativeio/PulseOut.c \
 	nativeio/PWMOut.c \
@@ -132,6 +131,7 @@ SRC_SHARED_MODULE = \
 	bitbangio/I2C.c \
 	bitbangio/OneWire.c \
 	bitbangio/SPI.c \
+	nativeio/I2C.c \
 	nativeio/OneWire.c \
 
 SRC_SHARED_MODULE_EXPANDED = $(addprefix shared-bindings/, $(SRC_SHARED_MODULE)) \

esp8266/common-hal/nativeio/types.h

@@ -34,8 +34,8 @@
 
 #include "py/obj.h"
 
-// Use the bitbang wrapper for OneWire
-// TODO(tannewt): Wrap bitbangio for I2C too.
+// Use the bitbang wrapper for I2C and OneWire
+#include "shared-module/nativeio/I2C.h"
 #include "shared-module/nativeio/OneWire.h"
 
 typedef struct {
@@ -48,11 +48,6 @@ typedef struct {
     mp_obj_base_t base;
 } nativeio_analogout_obj_t;
 
-// Not supported, throws error on construction.
-typedef struct {
-    mp_obj_base_t base;
-} nativeio_i2c_obj_t;
-
 typedef struct {
     mp_obj_base_t base;
     bool locked;

shared-module/nativeio/I2C.c

@@ -3,7 +3,7 @@
  *
  * The MIT License (MIT)
  *
- * Copyright (c) 2016 Scott Shawcroft
+ * Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -25,39 +25,42 @@
  */
 
 #include "shared-bindings/nativeio/I2C.h"
+#include "shared-bindings/bitbangio/I2C.h"
 #include "py/mperrno.h"
 #include "py/nlr.h"
 
 void common_hal_nativeio_i2c_construct(nativeio_i2c_obj_t *self,
         const mcu_pin_obj_t* scl, const mcu_pin_obj_t* sda, uint32_t freq) {
-    nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError,
-        "No hardware support for I2C. Use bitbangio instead."));
+    shared_module_bitbangio_i2c_construct(&self->bitbang, scl, sda, freq);
 }
 
 void common_hal_nativeio_i2c_deinit(nativeio_i2c_obj_t *self) {
+    shared_module_bitbangio_i2c_deinit(&self->bitbang);
 }
 
 bool common_hal_nativeio_i2c_probe(nativeio_i2c_obj_t *self, uint8_t addr) {
-    return false;
+    return shared_module_bitbangio_i2c_probe(&self->bitbang, addr);
 }
 
 bool common_hal_nativeio_i2c_try_lock(nativeio_i2c_obj_t *self) {
-    return false;
+    return shared_module_bitbangio_i2c_try_lock(&self->bitbang);
 }
 
 bool common_hal_nativeio_i2c_has_lock(nativeio_i2c_obj_t *self) {
-    return false;
+    return shared_module_bitbangio_i2c_has_lock(&self->bitbang);
 }
 
 void common_hal_nativeio_i2c_unlock(nativeio_i2c_obj_t *self) {
+    shared_module_bitbangio_i2c_unlock(&self->bitbang);
 }
 
 uint8_t common_hal_nativeio_i2c_write(nativeio_i2c_obj_t *self, uint16_t addr,
         const uint8_t * data, size_t len, bool transmit_stop_bit) {
-    return MP_EIO;
+    return shared_module_bitbangio_i2c_write(&self->bitbang, addr, data, len,
+        transmit_stop_bit);
 }
 
 uint8_t common_hal_nativeio_i2c_read(nativeio_i2c_obj_t *self, uint16_t addr,
         uint8_t * data, size_t len) {
-    return MP_EIO;
+    return shared_module_bitbangio_i2c_read(&self->bitbang, addr, data, len);
 }

shared-module/nativeio/I2C.h

@@ -0,0 +1,42 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+// This defines the types used to underly the standard nativeio Python objects.
+// The shared API is defined in terms of these types.
+
+#ifndef __MICROPY_INCLUDED_ATMEL_SAMD_SHARED_MODULE_NATIVEIO_I2C_H__
+#define __MICROPY_INCLUDED_ATMEL_SAMD_SHARED_MODULE_NATIVEIO_I2C_H__
+
+#include "shared-module/bitbangio/types.h"
+
+#include "py/obj.h"
+
+typedef struct {
+    mp_obj_base_t base;
+    bitbangio_i2c_obj_t bitbang;
+} nativeio_i2c_obj_t;
+
+#endif // __MICROPY_INCLUDED_ATMEL_SAMD_SHARED_MODULE_NATIVEIO_I2C_H__