extmod/machine_pinbase: Implementation of PinBase class.

Allows to translate C-level pin API to Python-level pin API. In other
words, allows to implement a pin class and Python which will be usable
for efficient C-coded algorithms, like bitbanging SPI/I2C, time_pulse,
etc.

extmod/machine_pinbase.c

+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 Paul Sokolovsky
+ *
+ * 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.
+ */
+
+#include "py/mpconfig.h"
+#if MICROPY_PY_MACHINE
+
+#include "py/obj.h"
+#include "py/runtime.h"
+#include "extmod/virtpin.h"
+
+// PinBase class
+
+// As this is abstract class, its instance is null.
+// But there should be an instance, as the rest of instance code
+// expects that there will be concrete object for inheritance.
+typedef struct _mp_pinbase_t {
+    mp_obj_base_t base;
+} mp_pinbase_t;
+
+STATIC const mp_obj_type_t pinbase_type;
+
+STATIC mp_pinbase_t pinbase_singleton = {
+    .base = { &pinbase_type },
+};
+
+STATIC mp_obj_t pinbase_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    (void)type;
+    (void)n_args;
+    (void)n_kw;
+    (void)args;
+    return MP_ROM_PTR(&pinbase_singleton);
+}
+
+mp_uint_t pinbase_ioctl(mp_obj_t obj, mp_uint_t request, uintptr_t arg, int *errcode);
+mp_uint_t pinbase_ioctl(mp_obj_t obj, mp_uint_t request, uintptr_t arg, int *errcode) {
+    (void)errcode;
+    switch (request) {
+        case MP_PIN_READ: {
+            mp_obj_t dest[2];
+            mp_load_method(obj, MP_QSTR_value, dest);
+            return mp_obj_get_int(mp_call_method_n_kw(0, 0, dest));
+        }
+        case MP_PIN_WRITE: {
+            mp_obj_t dest[3];
+            mp_load_method(obj, MP_QSTR_value, dest);
+            dest[2] = (arg == 0 ? mp_const_false : mp_const_true);
+            mp_call_method_n_kw(1, 0, dest);
+            return 0;
+        }
+    }
+    return -1;
+}
+
+STATIC const mp_pin_p_t pinbase_pin_p = {
+    .ioctl = pinbase_ioctl,
+};
+
+const mp_obj_type_t machine_pinbase_type = {
+    { &mp_type_type },
+    .name = MP_QSTR_PinBase,
+    .make_new = pinbase_make_new,
+    .protocol = &pinbase_pin_p,
+};
+
+#endif // MICROPY_PY_MACHINE

extmod/machine_pinbase.h

+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 Paul Sokolovsky
+ *
+ * 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.
+ */
+
+
+#ifndef __MICROPY_INCLUDED_EXTMOD_MACHINE_PINBASE_H__
+#define __MICROPY_INCLUDED_EXTMOD_MACHINE_PINBASE_H__
+
+#include "py/obj.h"
+
+extern const mp_obj_type_t machine_pinbase_type;
+
+#endif // __MICROPY_INCLUDED_EXTMOD_MACHINE_PINBASE_H__

py/py.mk

@@ -201,6 +201,7 @@ PY_O_BASENAME = \
 	../extmod/modubinascii.o \
 	../extmod/virtpin.o \
 	../extmod/machine_mem.o \
+	../extmod/machine_pinbase.o \
 	../extmod/machine_pulse.o \
 	../extmod/machine_i2c.o \
 	../extmod/modussl.o \