pin.c

#include <stdio.h>
#include <stdint.h>
#include <string.h>

#include "stm32f4xx_hal.h"

#include "nlr.h"
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "runtime.h"
#include "pin.h"

/// \moduleref pyb
/// \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 = pyb.Pin.board.X1
///
///     g = pyb.Pin(pyb.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:
///
///     pyb.Pin.dict["LeftMotorDir"] = pyb.Pin.cpu.C12
///     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 mp_obj_t pin_class_mapper;
STATIC mp_obj_t pin_class_map_dict;
STATIC bool pin_class_debug;

void pin_init(void) {
    pin_class_mapper = MP_OBJ_NULL;
    pin_class_map_dict = MP_OBJ_NULL;
    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 (pin_class_mapper != MP_OBJ_NULL) {
        pin_obj = mp_call_function_1(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 (pin_class_map_dict != MP_OBJ_NULL) {
        mp_map_t *pin_map_map = mp_obj_dict_get_map(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
    const char *pin_name = mp_obj_str_get_str(user_obj);
    pin_obj = pin_find_named_pin(pin_board_pins, pin_name);
    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, pin_name);
    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", pin_name));
}

/// \method __str__()
/// Return a string describing the pin object.
STATIC void pin_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
    pin_obj_t *self = self_in;
    print(env, "<Pin %s>", self->name);
}

STATIC mp_obj_t pin_obj_init(uint n_args, mp_obj_t *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(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
    mp_arg_check_num(n_args, n_kw, 1, 3, false);

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

    if (n_args >= 2) {
        // pin mode given, so configure this GPIO
        mp_obj_t args2[3] = {(mp_obj_t)pin, args[1], MP_OBJ_NULL};
        if (n_args == 3) {
            args2[2] = args[2];
        }
        pin_obj_init(n_args, args2);
    }

    return (mp_obj_t)pin;
}

/// \classmethod mapper([fun])
/// Get or set the pin mapper function.
STATIC mp_obj_t pin_mapper(uint n_args, mp_obj_t *args) {
    if (n_args > 1) {
        pin_class_mapper = args[1];
        return mp_const_none;
    }
    return 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(uint n_args, mp_obj_t *args) {
    if (n_args > 1) {
        pin_class_map_dict = args[1];
        return mp_const_none;
    }
    return 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(uint n_args, mp_obj_t *args) {
    if (n_args > 1) {
        pin_class_debug = mp_obj_is_true(args[1]);
        return mp_const_none;
    }
    return MP_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);

/// \method init(mode, pull=Pin.PULL_NONE)
/// Initialise the pin:
///
///   - `mode` can be one of:
///     - `Pin.IN` - configure the pin for input;
///     - `Pin.OUT_PP` - configure the pin for output, with push-pull control;
///     - `Pin.OUT_OD` - configure the pin for output, with open-drain control;
///     - `Pin.AF_PP` - configure the pin for alternate function, pull-pull;
///     - `Pin.AF_OD` - configure the pin for alternate function, open-drain;
///     - `Pin.ANALOG` - configure the pin for analog.
///   - `pull` can be one of:
///     - `Pin.PULL_NONE` - no pull up or down resistors;
///     - `Pin.PULL_UP` - enable the pull-up resistor;
///     - `Pin.PULL_DOWN` - enable the pull-down resistor.
///
/// Returns: `None`.
STATIC mp_obj_t pin_obj_init(uint n_args, mp_obj_t *args) {
    pin_obj_t *self = args[0];

    // get io mode
    uint mode = mp_obj_get_int(args[1]);
    if (!IS_GPIO_MODE(mode)) {
        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "invalid pin mode: %d", mode));
    }

    // get pull mode
    uint pull = GPIO_NOPULL;
    if (n_args >= 3) {
        pull = mp_obj_get_int(args[2]);
        if (!IS_GPIO_PULL(pull)) {
            nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "invalid pin pull: %d", pull));
        }
    }

    // configure the GPIO as requested
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.Pin = self->pin_mask;
    GPIO_InitStructure.Mode = mode;
    GPIO_InitStructure.Pull = pull;
    GPIO_InitStructure.Speed = GPIO_SPEED_FAST;
    GPIO_InitStructure.Alternate = 0;
    HAL_GPIO_Init(self->gpio, &GPIO_InitStructure);

    return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pin_init_obj, 2, 3, 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(uint n_args, mp_obj_t *args) {
    pin_obj_t *self = args[0];
    if (n_args == 1) {
        // get pin
        return MP_OBJ_NEW_SMALL_INT((self->gpio->IDR >> self->pin) & 1);
    } else {
        // set pin
        if (mp_obj_is_true(args[1])) {
            self->gpio->BSRRL = self->pin_mask;
        } else {
            self->gpio->BSRRH = self->pin_mask;
        }
        return mp_const_none;
    }
}
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;
    self->gpio->BSRRH = self->pin_mask;
    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;
    self->gpio->BSRRL = self->pin_mask;
    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(qstr_from_str(self->name));
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pin_name_obj, pin_name);

/// \method port()
/// Get the pin port.
STATIC mp_obj_t pin_port(mp_obj_t self_in) {
    pin_obj_t *self = self_in;
    return MP_OBJ_NEW_SMALL_INT((mp_small_int_t)self->port);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pin_port_obj, pin_port);

/// \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((mp_small_int_t)self->pin);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pin_pin_obj, pin_pin);

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_port),    (mp_obj_t)&pin_port_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_pin),     (mp_obj_t)&pin_pin_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 },
    { MP_OBJ_NEW_QSTR(MP_QSTR_cpu),     (mp_obj_t)&pin_cpu_pins_obj },

    // class constants
    /// \constant IN - initialise the pin to input mode
    /// \constant OUT_PP - initialise the pin to output mode with a push-pull drive
    /// \constant OUT_OD - initialise the pin to output mode with an open-drain drive
    /// \constant PULL_NONE - don't enable any pull up or down resistors on the pin
    /// \constant PULL_UP - enable the pull-up resistor on the pin
    /// \constant PULL_DOWN - enable the pull-down resistor on the pin
    { MP_OBJ_NEW_QSTR(MP_QSTR_IN),        MP_OBJ_NEW_SMALL_INT(GPIO_MODE_INPUT) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_OUT_PP),    MP_OBJ_NEW_SMALL_INT(GPIO_MODE_OUTPUT_PP) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_OUT_OD),    MP_OBJ_NEW_SMALL_INT(GPIO_MODE_OUTPUT_OD) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_AF_PP),     MP_OBJ_NEW_SMALL_INT(GPIO_MODE_AF_PP) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_AF_OD),     MP_OBJ_NEW_SMALL_INT(GPIO_MODE_AF_OD) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_ANALOG),    MP_OBJ_NEW_SMALL_INT(GPIO_MODE_ANALOG) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_PULL_NONE), MP_OBJ_NEW_SMALL_INT(GPIO_NOPULL) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_PULL_UP),   MP_OBJ_NEW_SMALL_INT(GPIO_PULLUP) },
    { MP_OBJ_NEW_QSTR(MP_QSTR_PULL_DOWN), MP_OBJ_NEW_SMALL_INT(GPIO_PULLDOWN) },
};

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,
    .locals_dict = (mp_obj_t)&pin_locals_dict,
};

STATIC void pin_af_obj_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
    pin_af_obj_t *self = self_in;
    print(env, "<Pin AF %d fn:%d unit:%d typ:%d>", self->idx, self->fn,
          self->unit, self->type);
}

const mp_obj_type_t pin_af_type = {
    { &mp_type_type },
    .name = MP_QSTR_PinAF,
    .print = pin_af_obj_print,
};