circuitpython/shared-bindings/busio/UART.c

474 lines
20 KiB
C

/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Scott Shawcroft for Adafruit Industries
*
* 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 "shared-bindings/busio/UART.h"
#include "shared-bindings/microcontroller/Pin.h"
#include "shared-bindings/util.h"
#include "shared/runtime/context_manager_helpers.h"
#include "shared/runtime/interrupt_char.h"
#include "py/stream.h"
#include "py/objproperty.h"
#include "py/objtype.h"
#include "py/runtime.h"
#include "py/stream.h"
#include "supervisor/shared/translate/translate.h"
#define STREAM_DEBUG(...) (void)0
// #define STREAM_DEBUG(...) mp_printf(&mp_plat_print __VA_OPT__(,) __VA_ARGS__)
//| class UART:
//| """A bidirectional serial protocol"""
//|
//| def __init__(
//| self,
//| tx: Optional[microcontroller.Pin] = None,
//| rx: Optional[microcontroller.Pin] = None,
//| *,
//| rts: Optional[microcontroller.Pin] = None,
//| cts: Optional[microcontroller.Pin] = None,
//| rs485_dir: Optional[microcontroller.Pin] = None,
//| rs485_invert: bool = False,
//| baudrate: int = 9600,
//| bits: int = 8,
//| parity: Optional[Parity] = None,
//| stop: int = 1,
//| timeout: float = 1,
//| receiver_buffer_size: int = 64
//| ) -> None:
//| """A common bidirectional serial protocol that uses an an agreed upon speed
//| rather than a shared clock line.
//|
//| :param ~microcontroller.Pin tx: the pin to transmit with, or ``None`` if this ``UART`` is receive-only.
//| :param ~microcontroller.Pin rx: the pin to receive on, or ``None`` if this ``UART`` is transmit-only.
//| :param ~microcontroller.Pin rts: the pin for rts, or ``None`` if rts not in use.
//| :param ~microcontroller.Pin cts: the pin for cts, or ``None`` if cts not in use.
//| :param ~microcontroller.Pin rs485_dir: the output pin for rs485 direction setting, or ``None`` if rs485 not in use.
//| :param bool rs485_invert: rs485_dir pin active high when set. Active low otherwise.
//| :param int baudrate: the transmit and receive speed.
//| :param int bits: the number of bits per byte, 5 to 9.
//| :param Parity parity: the parity used for error checking.
//| :param int stop: the number of stop bits, 1 or 2.
//| :param float timeout: the timeout in seconds to wait for the first character and between subsequent characters when reading. Raises ``ValueError`` if timeout >100 seconds.
//| :param int receiver_buffer_size: the character length of the read buffer (0 to disable). (When a character is 9 bits the buffer will be 2 * receiver_buffer_size bytes.)
//|
//| ``tx`` and ``rx`` cannot both be ``None``.
//|
//| *New in CircuitPython 4.0:* ``timeout`` has incompatibly changed units from milliseconds to seconds.
//| The new upper limit on ``timeout`` is meant to catch mistaken use of milliseconds.
//|
//| **Limitations:** RS485 is not supported on SAMD, nRF, Broadcom, Spresense, or STM.
//| On i.MX and Raspberry Pi RP2040, RS485 support is implemented in software:
//| The timing for the ``rs485_dir`` pin signal is done on a best-effort basis, and may not meet
//| RS485 specifications intermittently.
//| """
//| ...
typedef struct {
mp_obj_base_t base;
} busio_uart_parity_obj_t;
extern const busio_uart_parity_obj_t busio_uart_parity_even_obj;
extern const busio_uart_parity_obj_t busio_uart_parity_odd_obj;
#if CIRCUITPY_BUSIO_UART
STATIC void validate_timeout(mp_float_t timeout) {
mp_arg_validate_int_range((int)timeout, 0, 100, MP_QSTR_timeout);
}
#endif // CIRCUITPY_BUSIO_UART
STATIC mp_obj_t busio_uart_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
#if CIRCUITPY_BUSIO_UART
enum { ARG_tx, ARG_rx, ARG_baudrate, ARG_bits, ARG_parity, ARG_stop, ARG_timeout, ARG_receiver_buffer_size,
ARG_rts, ARG_cts, ARG_rs485_dir,ARG_rs485_invert};
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_tx, MP_ARG_OBJ, {.u_obj = mp_const_none} },
{ MP_QSTR_rx, MP_ARG_OBJ, {.u_obj = mp_const_none} },
{ MP_QSTR_baudrate, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 9600} },
{ MP_QSTR_bits, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} },
{ MP_QSTR_parity, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
{ MP_QSTR_stop, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1} },
{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NEW_SMALL_INT(1)} },
{ MP_QSTR_receiver_buffer_size, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 64} },
{ MP_QSTR_rts, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
{ MP_QSTR_cts, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
{ MP_QSTR_rs485_dir, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none } },
{ MP_QSTR_rs485_invert, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false } },
};
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);
const mcu_pin_obj_t *rx = validate_obj_is_free_pin_or_none(args[ARG_rx].u_obj, MP_QSTR_rx);
const mcu_pin_obj_t *tx = validate_obj_is_free_pin_or_none(args[ARG_tx].u_obj, MP_QSTR_tx);
const mcu_pin_obj_t *rts = validate_obj_is_free_pin_or_none(args[ARG_rts].u_obj, MP_QSTR_rts);
const mcu_pin_obj_t *cts = validate_obj_is_free_pin_or_none(args[ARG_cts].u_obj, MP_QSTR_cts);
const mcu_pin_obj_t *rs485_dir = validate_obj_is_free_pin_or_none(args[ARG_rs485_dir].u_obj, MP_QSTR_rs485_dir);
if ((tx == NULL) && (rx == NULL)) {
mp_raise_ValueError(translate("tx and rx cannot both be None"));
}
// Pins must be distinct.
if ((tx != NULL && (tx == rx || tx == rts || tx == cts || tx == rs485_dir)) ||
(rx != NULL && (rx == rts || rx == cts || rx == rs485_dir)) ||
(rts != NULL && (rts == cts || rts == rs485_dir)) ||
(cts != NULL && (cts == rs485_dir))) {
raise_ValueError_invalid_pins();
}
uint8_t bits = (uint8_t)mp_arg_validate_int_range(args[ARG_bits].u_int, 5, 9, MP_QSTR_bits);
busio_uart_parity_t parity = BUSIO_UART_PARITY_NONE;
if (args[ARG_parity].u_obj == MP_OBJ_FROM_PTR(&busio_uart_parity_even_obj)) {
parity = BUSIO_UART_PARITY_EVEN;
} else if (args[ARG_parity].u_obj == MP_OBJ_FROM_PTR(&busio_uart_parity_odd_obj)) {
parity = BUSIO_UART_PARITY_ODD;
}
uint8_t stop = (uint8_t)mp_arg_validate_int_range(args[ARG_stop].u_int, 1, 2, MP_QSTR_stop);
mp_float_t timeout = mp_obj_get_float(args[ARG_timeout].u_obj);
validate_timeout(timeout);
const bool rs485_invert = args[ARG_rs485_invert].u_bool;
// Always initially allocate the UART object within the long-lived heap.
// This is needed to avoid crashes with certain UART implementations which
// cannot accomodate being moved after creation. (See
// https://github.com/adafruit/circuitpython/issues/1056)
busio_uart_obj_t *self = m_new_ll_obj_with_finaliser(busio_uart_obj_t);
self->base.type = &busio_uart_type;
common_hal_busio_uart_construct(self, tx, rx, rts, cts, rs485_dir, rs485_invert,
args[ARG_baudrate].u_int, bits, parity, stop, timeout,
args[ARG_receiver_buffer_size].u_int, NULL, false);
return (mp_obj_t)self;
#else
mp_raise_NotImplementedError(NULL);
#endif // CIRCUITPY_BUSIO_UART
}
#if CIRCUITPY_BUSIO_UART
// Helper to ensure we have the native super class instead of a subclass.
STATIC busio_uart_obj_t *native_uart(mp_obj_t uart_obj) {
mp_obj_t native_uart = mp_obj_cast_to_native_base(uart_obj, MP_OBJ_FROM_PTR(&busio_uart_type));
if (native_uart == MP_OBJ_NULL) {
mp_raise_ValueError_varg(translate("Must be a %q subclass."), MP_QSTR_UART);
}
mp_obj_assert_native_inited(native_uart);
return MP_OBJ_TO_PTR(native_uart);
}
//| def deinit(self) -> None:
//| """Deinitialises the UART and releases any hardware resources for reuse."""
//| ...
STATIC mp_obj_t busio_uart_obj_deinit(mp_obj_t self_in) {
busio_uart_obj_t *self = native_uart(self_in);
common_hal_busio_uart_deinit(self);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(busio_uart_deinit_obj, busio_uart_obj_deinit);
STATIC void check_for_deinit(busio_uart_obj_t *self) {
if (common_hal_busio_uart_deinited(self)) {
raise_deinited_error();
}
}
//| def __enter__(self) -> UART:
//| """No-op used by Context Managers."""
//| ...
// Provided by context manager helper.
//| def __exit__(self) -> None:
//| """Automatically deinitializes the hardware when exiting a context. See
//| :ref:`lifetime-and-contextmanagers` for more info."""
//| ...
STATIC mp_obj_t busio_uart_obj___exit__(size_t n_args, const mp_obj_t *args) {
(void)n_args;
common_hal_busio_uart_deinit(MP_OBJ_TO_PTR(args[0]));
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(busio_uart___exit___obj, 4, 4, busio_uart_obj___exit__);
// These are standard stream methods. Code is in py/stream.c.
//
//| def read(self, nbytes: Optional[int] = None) -> Optional[bytes]:
//| """Read bytes. If ``nbytes`` is specified then read at most that many
//| bytes. Otherwise, read everything that arrives until the connection
//| times out. Providing the number of bytes expected is highly recommended
//| because it will be faster. If no bytes are read, return ``None``.
//|
//| .. note:: When no bytes are read due to a timeout, this function returns ``None``.
//| This matches the behavior of `io.RawIOBase.read` in Python 3, but
//| differs from pyserial which returns ``b''`` in that situation.
//|
//| :return: Data read
//| :rtype: bytes or None"""
//| ...
//| def readinto(self, buf: WriteableBuffer) -> Optional[int]:
//| """Read bytes into the ``buf``. Read at most ``len(buf)`` bytes.
//|
//| :return: number of bytes read and stored into ``buf``
//| :rtype: int or None (on a non-blocking error)
//|
//| *New in CircuitPython 4.0:* No length parameter is permitted."""
//| ...
//| def readline(self) -> bytes:
//| """Read a line, ending in a newline character, or
//| return ``None`` if a timeout occurs sooner, or
//| return everything readable if no newline is found and
//| ``timeout=0``
//|
//| :return: the line read
//| :rtype: bytes or None"""
//| ...
//| def write(self, buf: ReadableBuffer) -> Optional[int]:
//| """Write the buffer of bytes to the bus.
//|
//| *New in CircuitPython 4.0:* ``buf`` must be bytes, not a string.
//|
//| :return: the number of bytes written
//| :rtype: int or None"""
//| ...
// These three methods are used by the shared stream methods.
STATIC mp_uint_t busio_uart_read(mp_obj_t self_in, void *buf_in, mp_uint_t size, int *errcode) {
STREAM_DEBUG("busio_uart_read stream %d\n", size);
busio_uart_obj_t *self = native_uart(self_in);
check_for_deinit(self);
byte *buf = buf_in;
// make sure we want at least 1 char
if (size == 0) {
return 0;
}
return common_hal_busio_uart_read(self, buf, size, errcode);
}
STATIC mp_uint_t busio_uart_write(mp_obj_t self_in, const void *buf_in, mp_uint_t size, int *errcode) {
busio_uart_obj_t *self = native_uart(self_in);
check_for_deinit(self);
const byte *buf = buf_in;
return common_hal_busio_uart_write(self, buf, size, errcode);
}
STATIC mp_uint_t busio_uart_ioctl(mp_obj_t self_in, mp_uint_t request, mp_uint_t arg, int *errcode) {
busio_uart_obj_t *self = native_uart(self_in);
check_for_deinit(self);
mp_uint_t ret;
if (request == MP_STREAM_POLL) {
mp_uint_t flags = arg;
ret = 0;
if ((flags & MP_STREAM_POLL_RD) && common_hal_busio_uart_rx_characters_available(self) > 0) {
ret |= MP_STREAM_POLL_RD;
}
if ((flags & MP_STREAM_POLL_WR) && common_hal_busio_uart_ready_to_tx(self)) {
ret |= MP_STREAM_POLL_WR;
}
} else {
*errcode = MP_EINVAL;
ret = MP_STREAM_ERROR;
}
return ret;
}
//| baudrate: int
//| """The current baudrate."""
STATIC mp_obj_t busio_uart_obj_get_baudrate(mp_obj_t self_in) {
busio_uart_obj_t *self = native_uart(self_in);
check_for_deinit(self);
return MP_OBJ_NEW_SMALL_INT(common_hal_busio_uart_get_baudrate(self));
}
MP_DEFINE_CONST_FUN_OBJ_1(busio_uart_get_baudrate_obj, busio_uart_obj_get_baudrate);
STATIC mp_obj_t busio_uart_obj_set_baudrate(mp_obj_t self_in, mp_obj_t baudrate) {
busio_uart_obj_t *self = native_uart(self_in);
check_for_deinit(self);
common_hal_busio_uart_set_baudrate(self, mp_obj_get_int(baudrate));
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_2(busio_uart_set_baudrate_obj, busio_uart_obj_set_baudrate);
MP_PROPERTY_GETSET(busio_uart_baudrate_obj,
(mp_obj_t)&busio_uart_get_baudrate_obj,
(mp_obj_t)&busio_uart_set_baudrate_obj);
//| in_waiting: int
//| """The number of bytes in the input buffer, available to be read"""
STATIC mp_obj_t busio_uart_obj_get_in_waiting(mp_obj_t self_in) {
busio_uart_obj_t *self = native_uart(self_in);
check_for_deinit(self);
return MP_OBJ_NEW_SMALL_INT(common_hal_busio_uart_rx_characters_available(self));
}
MP_DEFINE_CONST_FUN_OBJ_1(busio_uart_get_in_waiting_obj, busio_uart_obj_get_in_waiting);
MP_PROPERTY_GETTER(busio_uart_in_waiting_obj,
(mp_obj_t)&busio_uart_get_in_waiting_obj);
//| timeout: float
//| """The current timeout, in seconds (float)."""
STATIC mp_obj_t busio_uart_obj_get_timeout(mp_obj_t self_in) {
busio_uart_obj_t *self = native_uart(self_in);
check_for_deinit(self);
return mp_obj_new_float(common_hal_busio_uart_get_timeout(self));
}
MP_DEFINE_CONST_FUN_OBJ_1(busio_uart_get_timeout_obj, busio_uart_obj_get_timeout);
STATIC mp_obj_t busio_uart_obj_set_timeout(mp_obj_t self_in, mp_obj_t timeout) {
busio_uart_obj_t *self = native_uart(self_in);
check_for_deinit(self);
mp_float_t timeout_float = mp_obj_get_float(timeout);
validate_timeout(timeout_float);
common_hal_busio_uart_set_timeout(self, timeout_float);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_2(busio_uart_set_timeout_obj, busio_uart_obj_set_timeout);
MP_PROPERTY_GETSET(busio_uart_timeout_obj,
(mp_obj_t)&busio_uart_get_timeout_obj,
(mp_obj_t)&busio_uart_set_timeout_obj);
//| def reset_input_buffer(self) -> None:
//| """Discard any unread characters in the input buffer."""
//| ...
//|
STATIC mp_obj_t busio_uart_obj_reset_input_buffer(mp_obj_t self_in) {
busio_uart_obj_t *self = native_uart(self_in);
check_for_deinit(self);
common_hal_busio_uart_clear_rx_buffer(self);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(busio_uart_reset_input_buffer_obj, busio_uart_obj_reset_input_buffer);
#endif // CIRCUITPY_BUSIO_UART
//| class Parity:
//| """Enum-like class to define the parity used to verify correct data transfer."""
//|
//| ODD: int
//| """Total number of ones should be odd."""
//|
//| EVEN: int
//| """Total number of ones should be even."""
//|
const mp_obj_type_t busio_uart_parity_type;
const busio_uart_parity_obj_t busio_uart_parity_odd_obj = {
{ &busio_uart_parity_type },
};
const busio_uart_parity_obj_t busio_uart_parity_even_obj = {
{ &busio_uart_parity_type },
};
STATIC const mp_rom_map_elem_t busio_uart_parity_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_ODD), MP_ROM_PTR(&busio_uart_parity_odd_obj) },
{ MP_ROM_QSTR(MP_QSTR_EVEN), MP_ROM_PTR(&busio_uart_parity_even_obj) },
};
STATIC MP_DEFINE_CONST_DICT(busio_uart_parity_locals_dict, busio_uart_parity_locals_dict_table);
STATIC void busio_uart_parity_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
qstr parity = MP_QSTR_ODD;
if (self_in == MP_ROM_PTR(&busio_uart_parity_even_obj)) {
parity = MP_QSTR_EVEN;
}
mp_printf(print, "%q.%q.%q.%q", MP_QSTR_busio, MP_QSTR_UART, MP_QSTR_Parity, parity);
}
const mp_obj_type_t busio_uart_parity_type = {
{ &mp_type_type },
.name = MP_QSTR_Parity,
.print = busio_uart_parity_print,
.locals_dict = (mp_obj_dict_t *)&busio_uart_parity_locals_dict,
};
STATIC const mp_rom_map_elem_t busio_uart_locals_dict_table[] = {
#if CIRCUITPY_BUSIO_UART
{ MP_ROM_QSTR(MP_QSTR___del__), MP_ROM_PTR(&busio_uart_deinit_obj) },
{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&busio_uart_deinit_obj) },
{ MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
{ MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&busio_uart___exit___obj) },
// Standard stream methods.
{ MP_OBJ_NEW_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_stream_read_obj) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_readline), MP_ROM_PTR(&mp_stream_unbuffered_readline_obj)},
{ MP_OBJ_NEW_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_stream_readinto_obj) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_stream_write_obj) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_reset_input_buffer), MP_ROM_PTR(&busio_uart_reset_input_buffer_obj) },
// Properties
{ MP_ROM_QSTR(MP_QSTR_baudrate), MP_ROM_PTR(&busio_uart_baudrate_obj) },
{ MP_ROM_QSTR(MP_QSTR_in_waiting), MP_ROM_PTR(&busio_uart_in_waiting_obj) },
{ MP_ROM_QSTR(MP_QSTR_timeout), MP_ROM_PTR(&busio_uart_timeout_obj) },
#endif // CIRCUITPY_BUSIO_UART
// Nested Enum-like Classes.
{ MP_ROM_QSTR(MP_QSTR_Parity), MP_ROM_PTR(&busio_uart_parity_type) },
};
STATIC MP_DEFINE_CONST_DICT(busio_uart_locals_dict, busio_uart_locals_dict_table);
#if CIRCUITPY_BUSIO_UART
STATIC const mp_stream_p_t uart_stream_p = {
MP_PROTO_IMPLEMENT(MP_QSTR_protocol_stream)
.read = busio_uart_read,
.write = busio_uart_write,
.ioctl = busio_uart_ioctl,
.is_text = false,
// Disallow optional length argument for .readinto()
.pyserial_readinto_compatibility = true,
};
const mp_obj_type_t busio_uart_type = {
{ &mp_type_type },
.flags = MP_TYPE_FLAG_EXTENDED,
.name = MP_QSTR_UART,
.make_new = busio_uart_make_new,
.locals_dict = (mp_obj_dict_t *)&busio_uart_locals_dict,
MP_TYPE_EXTENDED_FIELDS(
.getiter = mp_identity_getiter,
.iternext = mp_stream_unbuffered_iter,
.protocol = &uart_stream_p,
),
};
#else
const mp_obj_type_t busio_uart_type = {
{ &mp_type_type },
.name = MP_QSTR_UART,
.make_new = busio_uart_make_new,
.locals_dict = (mp_obj_dict_t *)&busio_uart_locals_dict,
};
#endif // CIRCUITPY_BUSIO_UART