WIP Support for I2C in MicroPython

Just the basic files created - compiles but no meaningful content is read.

lib/micropython/meson.build

@@ -194,4 +194,5 @@ micropython_extmod_sources = files(
   'micropython/extmod/modure.c',
   'micropython/extmod/moduselect.c',
   'micropython/extmod/modutimeq.c',
+  'micropython/extmod/machine_i2c.c',
 )

pycardium/meson.build

@@ -13,6 +13,8 @@ modsrc = files(
   'modules/sys_display.c',
   'modules/utime.c',
   'modules/vibra.c',
+  'modules/modmachine.c',
+  'modules/machine_i2c.c',
 )
 
 #################################

pycardium/modules/machine_i2c.c

+#include <string.h>
+
+#include "py/obj.h"
+#include "py/objlist.h"
+#include "py/runtime.h"
+#include "py/mphal.h"
+
+#include "extmod/machine_i2c.h"
+#include "i2c.h"
+
+#define MICROPY_HW_I2C1_NAME "X"
+#define MICROPY_HW_I2C2_NAME "Y"
+
+STATIC const mp_obj_type_t machine_hard_i2c_type;
+
+typedef struct _machine_hard_i2c_obj_t {
+    mp_obj_base_t base;
+    mxc_i2c_regs_t *i2c;
+} machine_hard_i2c_obj_t;
+
+STATIC const machine_hard_i2c_obj_t machine_hard_i2c_obj[2] = {
+    [0] = {{&machine_hard_i2c_type}, MXC_I2C1_BUS0},
+    [1] = {{&machine_hard_i2c_type}, MXC_I2C1_BUS1},
+};
+
+
+int machine_hard_i2c_transfer(mp_obj_base_t *self_in, uint16_t addr, size_t n, mp_machine_i2c_buf_t *bufs, unsigned int flags) {
+    machine_hard_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    if (flags & MP_MACHINE_I2C_FLAG_READ) {
+	return I2C_MasterRead(self->i2c, addr, bufs->buf, bufs->len, !(flags & MP_MACHINE_I2C_FLAG_STOP));
+    } else {
+	return I2C_MasterRead(self->i2c, addr, bufs->buf, bufs->len, !(flags & MP_MACHINE_I2C_FLAG_STOP));
+    }
+}
+
+
+/******************************************************************************/
+/* MicroPython bindings for machine API                                       */
+
+mp_obj_t machine_hard_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
+    // parse args
+    enum { ARG_id };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_id, MP_ARG_REQUIRED | MP_ARG_OBJ },
+    };
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    // work out i2c bus
+    int i2c_id = 0;
+    if (!mp_obj_is_str(args[ARG_id].u_obj)) {
+        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
+                "Provide I2C bus as string"));
+    }
+
+    const char *port = mp_obj_str_get_str(args[ARG_id].u_obj);
+    if (strcmp(port, MICROPY_HW_I2C1_NAME) == 0) {
+        i2c_id = 1;
+    } else if (strcmp(port, MICROPY_HW_I2C2_NAME) == 0) {
+        i2c_id = 2;
+    } else {
+        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
+            "I2C(%s) doesn't exist", port));
+    }
+
+    // get static peripheral object
+    machine_hard_i2c_obj_t *self = (machine_hard_i2c_obj_t*)&machine_hard_i2c_obj[i2c_id - 1];
+    return MP_OBJ_FROM_PTR(self);
+}
+
+STATIC const mp_machine_i2c_p_t machine_hard_i2c_p = {
+    .transfer = machine_hard_i2c_transfer,
+};
+
+STATIC const mp_obj_type_t machine_hard_i2c_type = {
+    { &mp_type_type },
+    .name = MP_QSTR_I2C,
+    .make_new = machine_hard_i2c_make_new,
+    .protocol = &machine_hard_i2c_p,
+    .locals_dict = (mp_obj_dict_t*)&mp_machine_soft_i2c_locals_dict,
+};
+

pycardium/modules/modmachine.c

+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013-2015 Damien P. George
+ *
+ * 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 <stdio.h>
+#include <string.h>
+
+#include "py/gc.h"
+#include "py/runtime.h"
+#include "py/objstr.h"
+#include "py/mperrno.h"
+#include "py/mphal.h"
+#include "extmod/machine_i2c.h"
+#include "i2c.h"
+
+STATIC const mp_rom_map_elem_t machine_module_globals_table[] = {
+    { MP_ROM_QSTR(MP_QSTR___name__),            MP_ROM_QSTR(MP_QSTR_umachine) },
+    { MP_ROM_QSTR(MP_QSTR_I2C),                 MP_ROM_PTR(&machine_i2c_type) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(machine_module_globals, machine_module_globals_table);
+
+const mp_obj_module_t machine_module = {
+    .base = { &mp_type_module },
+    .globals = (mp_obj_dict_t*)&machine_module_globals,
+};
+
+MP_REGISTER_MODULE(MP_QSTR_umachine, machine_module, MODULE_UMACHINE_ENABLED);

pycardium/modules/qstrdefs.h

@@ -127,3 +127,6 @@ Q(NO_CONTACT)
 Q(CHAOS)
 Q(COMMUNICATION)
 Q(CAMP)
+
+/* umachine and i2c */
+Q(umachine)

pycardium/mpconfigport.h

@@ -44,6 +44,16 @@ int mp_hal_trng_read_int(void);
 #define MICROPY_PY_IO_FILEIO                (1)
 #define MICROPY_PY_UERRNO                   (1)
 
+/* I2C */ 
+#define mp_hal_delay_us_fast(us) mp_hal_delay_us(us)
+typedef void *mp_obj_t;
+int mp_virtual_pin_read(mp_obj_t pin);
+#define mp_hal_pin_open_drain(x) 
+#define mp_hal_pin_od_low(x)
+#define mp_hal_pin_od_high(x)
+#define MICROPY_PY_MACHINE_I2C              (1)
+#define MICROPY_PY_MACHINE_I2C_MAKE_NEW     machine_hard_i2c_make_new
+
 /* Modules */
 #define MODULE_BUTTONS_ENABLED              (1)
 #define MODULE_DISPLAY_ENABLED              (1)
@@ -55,6 +65,7 @@ int mp_hal_trng_read_int(void);
 #define MODULE_PERSONAL_STATE_ENABLED       (1)
 #define MODULE_UTIME_ENABLED                (1)
 #define MODULE_VIBRA_ENABLED                (1)
+#define MODULE_UMACHINE_ENABLED             (1)
 
 /*
  * This port is intended to be 32-bit, but unfortunately, int32_t for

pycardium/mphalport.c

@@ -163,3 +163,11 @@ int mp_hal_trng_read_int(void)
 	epic_trng_read((uint8_t *)&result, sizeof(result));
 	return result;
 }
+
+/******************************************************************************
+ * Dummy implementations
+ */
+int mp_virtual_pin_read(mp_obj_t pin)
+{
+	return 0;
+}