zephyr: Initial implementation of machine.Pin.

The integration with Zephyr is fairly clean but as MicroPython Hardware API
requires pin ID to be a single value, but Zephyr operates GPIO in terms of
ports and pins, not just pins, a "hierarchical" ID is required, using tuple
of (port, pin). Port is a string, effectively a device name of a GPIO port,
per Zephyr conventions these are "GPIO_0", "GPIO_1", etc.; pin is integer
number of pin with the port (supposed to be in range 0-31).

Example of pin initialization:

pin = Pin(("GPIO_1", 21), Pin.OUT)

(an LED on FRDM-K64F's Port B, Pin 21).

There is support for in/out pins and pull up/pull down but currently
there is no interrupt support.

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@linaro.org>
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>

5 files changed, 272 insertions, 0 deletions

diff --git a/zephyr/Makefile b/zephyr/Makefile
index bf0d9c959f..920336722e 100644
--- a/zephyr/Makefile
+++ b/zephyr/Makefile
@@ -35,6 +35,8 @@ INC += -I$(ZEPHYR_BASE)/net/ip/contiki/os
 SRC_C = main.c \
 	help.c \
 	modutime.c \
+	modmachine.c \
+	machine_pin.c \
 	uart_core.c \
 	lib/utils/stdout_helpers.c \
 	lib/utils/printf.c \
diff --git a/zephyr/machine_pin.c b/zephyr/machine_pin.c
new file mode 100644
index 0000000000..049255e9f6
--- /dev/null
+++ b/zephyr/machine_pin.c
@@ -0,0 +1,180 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013, 2014, 2015 Damien P. George
+ * Copyright (c) 2016 Linaro Limited
+ *
+ * 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 <stdint.h>
+#include <string.h>
+
+#include <zephyr.h>
+#include <gpio.h>
+
+#include "py/nlr.h"
+#include "py/runtime.h"
+#include "py/gc.h"
+#include "py/mphal.h"
+#include "modmachine.h"
+
+const mp_obj_base_t machine_pin_obj_template = {&machine_pin_type};
+
+STATIC void machine_pin_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
+    machine_pin_obj_t *self = self_in;
+    mp_printf(print, "<Pin %p %d>", self->port, self->pin);
+}
+
+// pin.init(mode, pull=None, *, value)
+STATIC mp_obj_t machine_pin_obj_init_helper(machine_pin_obj_t *self, mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    enum { ARG_mode, ARG_pull, ARG_value };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_mode, MP_ARG_REQUIRED | MP_ARG_INT },
+        { MP_QSTR_pull, MP_ARG_OBJ, {.u_obj = mp_const_none}},
+        { MP_QSTR_value, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL}},
+    };
+
+    // parse args
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    // get io mode
+    uint mode = args[ARG_mode].u_int;
+
+    // get pull mode
+    uint pull = GPIO_PUD_NORMAL;
+    if (args[ARG_pull].u_obj != mp_const_none) {
+        pull = mp_obj_get_int(args[ARG_pull].u_obj);
+    }
+
+    int ret = gpio_pin_configure(self->port, self->pin, mode | pull);
+    if (ret) {
+        mp_raise_ValueError("invalid pin");
+    }
+
+    // get initial value
+    if (args[ARG_value].u_obj != MP_OBJ_NULL) {
+        (void)gpio_pin_write(self->port, self->pin, mp_obj_is_true(args[ARG_value].u_obj));
+    }
+
+    return mp_const_none;
+}
+
+// constructor(drv_name, pin, ...)
+STATIC mp_obj_t machine_pin_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);
+
+    // get the wanted port
+    if (!MP_OBJ_IS_TYPE(args[0], &mp_type_tuple)) {
+        mp_raise_ValueError("Pin id must be tuple of (\"GPIO_x\", pin#)");
+    }
+    mp_obj_t *items;
+    mp_obj_get_array_fixed_n(args[0], 2, &items);
+    const char *drv_name = mp_obj_str_get_str(items[0]);
+    int wanted_pin = mp_obj_get_int(items[1]);
+    struct device *wanted_port = device_get_binding(drv_name);
+    if (!wanted_port) {
+        mp_raise_ValueError("invalid port");
+    }
+
+    machine_pin_obj_t *pin = m_new_obj(machine_pin_obj_t);
+    pin->base = machine_pin_obj_template;
+    pin->port = wanted_port;
+    pin->pin = wanted_pin;
+
+    if (n_args > 1 || n_kw > 0) {
+        // pin mode given, so configure this GPIO
+        mp_map_t kw_args;
+        mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
+        machine_pin_obj_init_helper(pin, n_args - 1, args + 1, &kw_args);
+    }
+
+    return (mp_obj_t)pin;
+}
+
+// fast method for getting/setting pin value
+STATIC mp_obj_t machine_pin_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    mp_arg_check_num(n_args, n_kw, 0, 1, false);
+    machine_pin_obj_t *self = self_in;
+    if (n_args == 0) {
+        uint32_t pin_val;
+        (void)gpio_pin_read(self->port, self->pin, &pin_val);
+        return MP_OBJ_NEW_SMALL_INT(pin_val);
+    } else {
+        (void)gpio_pin_write(self->port, self->pin, mp_obj_is_true(args[0]));
+        return mp_const_none;
+    }
+}
+
+// pin.init(mode, pull)
+STATIC mp_obj_t machine_pin_obj_init(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
+    return machine_pin_obj_init_helper(args[0], n_args - 1, args + 1, kw_args);
+}
+MP_DEFINE_CONST_FUN_OBJ_KW(machine_pin_init_obj, 1, machine_pin_obj_init);
+
+// pin.value([value])
+STATIC mp_obj_t machine_pin_value(size_t n_args, const mp_obj_t *args) {
+    return machine_pin_call(args[0], n_args - 1, 0, args + 1);
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_pin_value_obj, 1, 2, machine_pin_value);
+
+// pin.low()
+STATIC mp_obj_t machine_pin_low(mp_obj_t self_in) {
+    machine_pin_obj_t *self = self_in;
+    (void)gpio_pin_write(self->port, self->pin, 0);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(machine_pin_low_obj, machine_pin_low);
+
+// pin.high()
+STATIC mp_obj_t machine_pin_high(mp_obj_t self_in) {
+    machine_pin_obj_t *self = self_in;
+    (void)gpio_pin_write(self->port, self->pin, 1);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(machine_pin_high_obj, machine_pin_high);
+
+STATIC const mp_map_elem_t machine_pin_locals_dict_table[] = {
+    // instance methods
+    { MP_OBJ_NEW_QSTR(MP_QSTR_init),    (mp_obj_t)&machine_pin_init_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_value),   (mp_obj_t)&machine_pin_value_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_low),     (mp_obj_t)&machine_pin_low_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_high),    (mp_obj_t)&machine_pin_high_obj },
+
+    // class constants
+    { MP_OBJ_NEW_QSTR(MP_QSTR_IN),        MP_OBJ_NEW_SMALL_INT(GPIO_DIR_IN) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_OUT),       MP_OBJ_NEW_SMALL_INT(GPIO_DIR_OUT) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_PULL_UP),   MP_OBJ_NEW_SMALL_INT(GPIO_PUD_PULL_UP) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_PULL_DOWN), MP_OBJ_NEW_SMALL_INT(GPIO_PUD_PULL_DOWN) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(machine_pin_locals_dict, machine_pin_locals_dict_table);
+
+const mp_obj_type_t machine_pin_type = {
+    { &mp_type_type },
+    .name = MP_QSTR_Pin,
+    .print = machine_pin_print,
+    .make_new = machine_pin_make_new,
+    .call = machine_pin_call,
+    .locals_dict = (mp_obj_t)&machine_pin_locals_dict,
+};
diff --git a/zephyr/modmachine.c b/zephyr/modmachine.c
new file mode 100644
index 0000000000..6194a95dad
--- /dev/null
+++ b/zephyr/modmachine.c
@@ -0,0 +1,71 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013-2015 Damien P. George
+ * Copyright (c) 2016 Paul Sokolovsky
+ * Copyright (c) 2016 Linaro Limited
+ *
+ * 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 <stdint.h>
+#include <stdio.h>
+
+#include "py/obj.h"
+#include "py/runtime.h"
+#include "extmod/machine_mem.h"
+#include "extmod/machine_pulse.h"
+#include "extmod/machine_i2c.h"
+#include "modmachine.h"
+
+#if MICROPY_PY_MACHINE
+
+STATIC mp_obj_t machine_reset(void) {
+    printf("Warning: %s is not implemented\n", __func__);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
+
+STATIC mp_obj_t machine_reset_cause(void) {
+    printf("Warning: %s is not implemented\n", __func__);
+    return MP_OBJ_NEW_SMALL_INT(42);
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);
+
+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_reset), MP_ROM_PTR(&machine_reset_obj) },
+    { MP_ROM_QSTR(MP_QSTR_reset_cause), MP_ROM_PTR(&machine_reset_cause_obj) },
+
+    { MP_ROM_QSTR(MP_QSTR_Pin), MP_ROM_PTR(&machine_pin_type) },
+
+    // reset causes
+    /*{ MP_ROM_QSTR(MP_QSTR_PWRON_RESET), MP_ROM_INT(REASON_DEFAULT_RST) },*/
+};
+
+STATIC MP_DEFINE_CONST_DICT(machine_module_globals, machine_module_globals_table);
+
+const mp_obj_module_t mp_module_machine = {
+    .base = { &mp_type_module },
+    .globals = (mp_obj_dict_t*)&machine_module_globals,
+};
+
+#endif // MICROPY_PY_MACHINE
diff --git a/zephyr/modmachine.h b/zephyr/modmachine.h
new file mode 100644
index 0000000000..596c59b178
--- /dev/null
+++ b/zephyr/modmachine.h
@@ -0,0 +1,16 @@
+#ifndef __MICROPY_INCLUDED_ZEPHYR_MODMACHINE_H__
+#define __MICROPY_INCLUDED_ZEPHYR_MODMACHINE_H__
+
+#include "py/obj.h"
+
+extern const mp_obj_type_t machine_pin_type;
+
+MP_DECLARE_CONST_FUN_OBJ_0(machine_info_obj);
+
+typedef struct _machine_pin_obj_t {
+    mp_obj_base_t base;
+    struct device *port;
+    uint32_t pin;
+} machine_pin_obj_t;
+
+#endif // __MICROPY_INCLUDED_ZEPHYR_MODMACHINE_H__
diff --git a/zephyr/mpconfigport.h b/zephyr/mpconfigport.h
index 2f12cf7112..0a3905c3c5 100644
--- a/zephyr/mpconfigport.h
+++ b/zephyr/mpconfigport.h
@@ -53,6 +53,7 @@
 #define MICROPY_PY_CMATH            (0)
 #define MICROPY_PY_IO               (0)
 #define MICROPY_PY_MICROPYTHON_MEM_INFO (1)
+#define MICROPY_PY_MACHINE          (1)
 #define MICROPY_PY_STRUCT           (0)
 #define MICROPY_PY_UTIME            (1)
 #define MICROPY_PY_UTIME_MP_HAL     (1)
@@ -90,6 +91,7 @@ typedef long mp_off_t;
     mp_obj_t mp_kbd_exception; \
     const char *readline_hist[8];
 
+extern const struct _mp_obj_module_t mp_module_machine;
 extern const struct _mp_obj_module_t mp_module_time;
 
 #if MICROPY_PY_UTIME
@@ -99,6 +101,7 @@ extern const struct _mp_obj_module_t mp_module_time;
 #endif
 
 #define MICROPY_PORT_BUILTIN_MODULES \
+    { MP_OBJ_NEW_QSTR(MP_QSTR_machine), (mp_obj_t)&mp_module_machine }, \
     MICROPY_PY_UTIME_DEF \
 
 // extra built in names to add to the global namespace