circuitpython/atmel-samd/modmachine_pin.c

/*
 * This file is part of the Micro Python project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2013, 2014 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 <stdint.h>
#include <string.h>

#include "py/nlr.h"
#include "py/runtime.h"
#include "py/mphal.h"
#include "modmachine_pin.h"

#include "asf/sam0/drivers/port/port.h"

/// \moduleref machine
/// \class Pin - control I/O pins
///
/// A pin is the basic object to control I/O pins.  It has methods to set
/// the mode of the pin (input, output, etc) and methods to get and set the
/// digital logic level.  For analog control of a pin, see the ADC class.
///
/// Usage Model:
///
/// All Board Pins are predefined as pyb.Pin.board.Name
///
///     x1_pin = machine.Pin.board.X1
///
///     g = machine.Pin(machine.Pin.board.X1, pyb.Pin.IN)
///
/// CPU pins which correspond to the board pins are available
/// as `pyb.cpu.Name`. For the CPU pins, the names are the port letter
/// followed by the pin number. On the PYBv1.0, `pyb.Pin.board.X1` and
/// `pyb.Pin.cpu.B6` are the same pin.
///
/// You can also use strings:
///
///     g = pyb.Pin('X1', pyb.Pin.OUT_PP)
///
/// Users can add their own names:
///
///     MyMapperDict = { 'LeftMotorDir' : pyb.Pin.cpu.C12 }
///     pyb.Pin.dict(MyMapperDict)
///     g = pyb.Pin("LeftMotorDir", pyb.Pin.OUT_OD)
///
/// and can query mappings
///
///     pin = pyb.Pin("LeftMotorDir")
///
/// Users can also add their own mapping function:
///
///     def MyMapper(pin_name):
///        if pin_name == "LeftMotorDir":
///            return pyb.Pin.cpu.A0
///
///     pyb.Pin.mapper(MyMapper)
///
/// So, if you were to call: `pyb.Pin("LeftMotorDir", pyb.Pin.OUT_PP)`
/// then `"LeftMotorDir"` is passed directly to the mapper function.
///
/// To summarise, the following order determines how things get mapped into
/// an ordinal pin number:
///
/// 1. Directly specify a pin object
/// 2. User supplied mapping function
/// 3. User supplied mapping (object must be usable as a dictionary key)
/// 4. Supply a string which matches a board pin
/// 5. Supply a string which matches a CPU port/pin
///
/// You can set `pyb.Pin.debug(True)` to get some debug information about
/// how a particular object gets mapped to a pin.

// Pin class variables
STATIC bool pin_class_debug;

void pin_init0(void) {
    MP_STATE_PORT(pin_class_mapper) = mp_const_none;
    MP_STATE_PORT(pin_class_map_dict) = mp_const_none;
    pin_class_debug = false;
}

// C API used to convert a user-supplied pin name into an ordinal pin number.
const pin_obj_t *pin_find(mp_obj_t user_obj) {
    const pin_obj_t *pin_obj;

    // If a pin was provided, then use it
    if (MP_OBJ_IS_TYPE(user_obj, &pin_type)) {
        pin_obj = user_obj;
        if (pin_class_debug) {
            printf("Pin map passed pin ");
            mp_obj_print((mp_obj_t)pin_obj, PRINT_STR);
            printf("\n");
        }
        return pin_obj;
    }

    if (MP_STATE_PORT(pin_class_mapper) != mp_const_none) {
        pin_obj = mp_call_function_1(MP_STATE_PORT(pin_class_mapper), user_obj);
        if (pin_obj != mp_const_none) {
            if (!MP_OBJ_IS_TYPE(pin_obj, &pin_type)) {
                nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "Pin.mapper didn't return a Pin object"));
            }
            if (pin_class_debug) {
                printf("Pin.mapper maps ");
                mp_obj_print(user_obj, PRINT_REPR);
                printf(" to ");
                mp_obj_print((mp_obj_t)pin_obj, PRINT_STR);
                printf("\n");
            }
            return pin_obj;
        }
        // The pin mapping function returned mp_const_none, fall through to
        // other lookup methods.
    }

    if (MP_STATE_PORT(pin_class_map_dict) != mp_const_none) {
        mp_map_t *pin_map_map = mp_obj_dict_get_map(MP_STATE_PORT(pin_class_map_dict));
        mp_map_elem_t *elem = mp_map_lookup(pin_map_map, user_obj, MP_MAP_LOOKUP);
        if (elem != NULL && elem->value != NULL) {
            pin_obj = elem->value;
            if (pin_class_debug) {
                printf("Pin.map_dict maps ");
                mp_obj_print(user_obj, PRINT_REPR);
                printf(" to ");
                mp_obj_print((mp_obj_t)pin_obj, PRINT_STR);
                printf("\n");
            }
            return pin_obj;
        }
    }

    // See if the pin name matches a board pin
    pin_obj = pin_find_named_pin(&pin_board_pins_locals_dict, user_obj);
    if (pin_obj) {
        if (pin_class_debug) {
            printf("Pin.board maps ");
            mp_obj_print(user_obj, PRINT_REPR);
            printf(" to ");
            mp_obj_print((mp_obj_t)pin_obj, PRINT_STR);
            printf("\n");
        }
        return pin_obj;
    }

    // See if the pin name matches a cpu pin
    pin_obj = pin_find_named_pin(&pin_cpu_pins_locals_dict, user_obj);
    if (pin_obj) {
        if (pin_class_debug) {
            printf("Pin.cpu maps ");
            mp_obj_print(user_obj, PRINT_REPR);
            printf(" to ");
            mp_obj_print((mp_obj_t)pin_obj, PRINT_STR);
            printf("\n");
        }
        return pin_obj;
    }

    nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "pin '%s' not a valid pin identifier", mp_obj_str_get_str(user_obj)));
}

/// \method __str__()
/// Return a string describing the pin object.
STATIC void pin_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
    pin_obj_t *self = self_in;

    // pin name
    mp_printf(print, "Pin(Pin.cpu.%q)", self->name);
}

STATIC mp_obj_t pin_obj_init_helper(const pin_obj_t *pin, mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args);

/// \classmethod \constructor(id, ...)
/// Create a new Pin object associated with the id.  If additional arguments are given,
/// they are used to initialise the pin.  See `init`.
STATIC mp_obj_t pin_make_new(const mp_obj_type_t *type, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
    mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);

    // Run an argument through the mapper and return the result.
    const pin_obj_t *pin = pin_find(args[0]);

    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);
        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 pin_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
    mp_arg_check_num(n_args, n_kw, 0, 1, false);
    pin_obj_t *self = self_in;
    if (n_args == 0) {
        // get pin
        // TODO(tannewt): Do we need to switch read functions based on our direction?
        return MP_OBJ_NEW_SMALL_INT(port_pin_get_input_level(self->pin));
    } else {
        // set pin
        port_pin_set_output_level(self->pin, mp_obj_is_true(args[0]));
        return mp_const_none;
    }
}

/// \classmethod mapper([fun])
/// Get or set the pin mapper function.
STATIC mp_obj_t pin_mapper(mp_uint_t n_args, const mp_obj_t *args) {
    if (n_args > 1) {
        MP_STATE_PORT(pin_class_mapper) = args[1];
        return mp_const_none;
    }
    return MP_STATE_PORT(pin_class_mapper);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pin_mapper_fun_obj, 1, 2, pin_mapper);
STATIC MP_DEFINE_CONST_CLASSMETHOD_OBJ(pin_mapper_obj, (mp_obj_t)&pin_mapper_fun_obj);

/// \classmethod dict([dict])
/// Get or set the pin mapper dictionary.
STATIC mp_obj_t pin_map_dict(mp_uint_t n_args, const mp_obj_t *args) {
    if (n_args > 1) {
        MP_STATE_PORT(pin_class_map_dict) = args[1];
        return mp_const_none;
    }
    return MP_STATE_PORT(pin_class_map_dict);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pin_map_dict_fun_obj, 1, 2, pin_map_dict);
STATIC MP_DEFINE_CONST_CLASSMETHOD_OBJ(pin_map_dict_obj, (mp_obj_t)&pin_map_dict_fun_obj);

/// \classmethod debug([state])
/// Get or set the debugging state (`True` or `False` for on or off).
STATIC mp_obj_t pin_debug(mp_uint_t n_args, const mp_obj_t *args) {
    if (n_args > 1) {
        pin_class_debug = mp_obj_is_true(args[1]);
        return mp_const_none;
    }
    return mp_obj_new_bool(pin_class_debug);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pin_debug_fun_obj, 1, 2, pin_debug);
STATIC MP_DEFINE_CONST_CLASSMETHOD_OBJ(pin_debug_obj, (mp_obj_t)&pin_debug_fun_obj);

// init(mode, pull=None, *, value, alt)
STATIC mp_obj_t pin_obj_init_helper(const pin_obj_t *self, mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
    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
    enum port_pin_dir mode = args[0].u_int;
    switch(mode)
    {
      case PORT_PIN_DIR_INPUT:
      case PORT_PIN_DIR_OUTPUT:
      case PORT_PIN_DIR_OUTPUT_WTH_READBACK:
        //do the work
        break;

      default:
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "invalid pin mode: %d", mode));
    }

    // get pull mode
    enum port_pin_pull pull = PORT_PIN_PULL_NONE;
    if (args[1].u_obj != mp_const_none) {
        pull = mp_obj_get_int(args[1].u_obj);
    }
    switch(pull)
    {
      case PORT_PIN_PULL_NONE:
      case PORT_PIN_PULL_UP:
      case PORT_PIN_PULL_DOWN:
        //do the work
        break;

      default:
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "invalid pin pull: %d", pull));
    }

    // if given, set the pin value before initialising to prevent glitches
    if (args[2].u_obj != MP_OBJ_NULL) {
        port_pin_set_output_level(self->pin, mp_obj_is_true(args[2].u_obj));
    }

    // configure the GPIO as requested
    struct port_config pin_conf;
    port_get_config_defaults(&pin_conf);

    pin_conf.direction  = mode;
    pin_conf.input_pull = pull;
    port_pin_set_config(self->pin, &pin_conf);

    return mp_const_none;
}

STATIC mp_obj_t pin_obj_init(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
    return pin_obj_init_helper(args[0], n_args - 1, args + 1, kw_args);
}
MP_DEFINE_CONST_FUN_OBJ_KW(pin_init_obj, 1, pin_obj_init);

/// \method value([value])
/// Get or set the digital logic level of the pin:
///
///   - With no argument, return 0 or 1 depending on the logic level of the pin.
///   - With `value` given, set the logic level of the pin.  `value` can be
///   anything that converts to a boolean.  If it converts to `True`, the pin
///   is set high, otherwise it is set low.
STATIC mp_obj_t pin_value(mp_uint_t n_args, const mp_obj_t *args) {
    return pin_call(args[0], n_args - 1, 0, args + 1);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pin_value_obj, 1, 2, pin_value);

/// \method low()
/// Set the pin to a low logic level.
STATIC mp_obj_t pin_low(mp_obj_t self_in) {
    pin_obj_t *self = self_in;
    port_pin_set_output_level(self->pin, false);
    return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pin_low_obj, pin_low);

/// \method high()
/// Set the pin to a high logic level.
STATIC mp_obj_t pin_high(mp_obj_t self_in) {
    pin_obj_t *self = self_in;
    port_pin_set_output_level(self->pin, true);
    return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pin_high_obj, pin_high);

/// \method name()
/// Get the pin name.
STATIC mp_obj_t pin_name(mp_obj_t self_in) {
    pin_obj_t *self = self_in;
    return MP_OBJ_NEW_QSTR(self->name);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pin_name_obj, pin_name);

/// \method names()
/// Returns the cpu and board names for this pin.
STATIC mp_obj_t pin_names(mp_obj_t self_in) {
    pin_obj_t *self = self_in;
    mp_obj_t result = mp_obj_new_list(0, NULL);
    mp_obj_list_append(result, MP_OBJ_NEW_QSTR(self->name));

    mp_map_t *map = mp_obj_dict_get_map((mp_obj_t)&pin_board_pins_locals_dict);
    mp_map_elem_t *elem = map->table;

    for (mp_uint_t i = 0; i < map->used; i++, elem++) {
        if (elem->value == self) {
            mp_obj_list_append(result, elem->key);
        }
    }
    return result;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pin_names_obj, pin_names);

/// \method pin()
/// Get the pin number.
STATIC mp_obj_t pin_pin(mp_obj_t self_in) {
    pin_obj_t *self = self_in;
    return MP_OBJ_NEW_SMALL_INT(self->pin);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pin_pin_obj, pin_pin);

/// \method gpio()
/// Returns the base address of the GPIO block associated with this pin.
STATIC mp_obj_t pin_gpio(mp_obj_t self_in) {
    pin_obj_t *self = self_in;
    return MP_OBJ_NEW_SMALL_INT((mp_int_t)port_get_group_from_gpio_pin(self->pin));
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pin_gpio_obj, pin_gpio);

STATIC const mp_map_elem_t pin_locals_dict_table[] = {
    // instance methods
    { MP_OBJ_NEW_QSTR(MP_QSTR_init),    (mp_obj_t)&pin_init_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_value),   (mp_obj_t)&pin_value_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_low),     (mp_obj_t)&pin_low_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_high),    (mp_obj_t)&pin_high_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_name),    (mp_obj_t)&pin_name_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_names),   (mp_obj_t)&pin_names_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_pin),     (mp_obj_t)&pin_pin_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_gpio),    (mp_obj_t)&pin_gpio_obj },

    // class methods
    { MP_OBJ_NEW_QSTR(MP_QSTR_mapper),  (mp_obj_t)&pin_mapper_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_dict),    (mp_obj_t)&pin_map_dict_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_debug),   (mp_obj_t)&pin_debug_obj },

    // class attributes
    { MP_OBJ_NEW_QSTR(MP_QSTR_board),   (mp_obj_t)&pin_board_pins_obj_type },
    { MP_OBJ_NEW_QSTR(MP_QSTR_cpu),     (mp_obj_t)&pin_cpu_pins_obj_type },

    // class constants
    { MP_OBJ_NEW_QSTR(MP_QSTR_IN),        MP_OBJ_NEW_SMALL_INT(PORT_PIN_DIR_INPUT) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_OUT),       MP_OBJ_NEW_SMALL_INT(PORT_PIN_DIR_OUTPUT) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_PULL_NONE),   MP_OBJ_NEW_SMALL_INT(PORT_PIN_PULL_NONE) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_PULL_UP),   MP_OBJ_NEW_SMALL_INT(PORT_PIN_PULL_UP) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_PULL_DOWN), MP_OBJ_NEW_SMALL_INT(PORT_PIN_PULL_DOWN) },
};

STATIC MP_DEFINE_CONST_DICT(pin_locals_dict, pin_locals_dict_table);

const mp_obj_type_t pin_type = {
    { &mp_type_type },
    .name = MP_QSTR_Pin,
    .print = pin_print,
    .make_new = pin_make_new,
    .call = pin_call,
    .locals_dict = (mp_obj_t)&pin_locals_dict,
};