circuitpython/shared-bindings/busio/I2C.c

398 lines
17 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Scott Shawcroft
*
* 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.
*/
// This file contains all of the Python API definitions for the
// busio.I2C class.
#include "shared-bindings/microcontroller/Pin.h"
#include "shared-bindings/busio/I2C.h"
#include "shared-bindings/util.h"
#include "shared/runtime/buffer_helper.h"
#include "shared/runtime/context_manager_helpers.h"
#include "py/binary.h"
#include "py/runtime.h"
//| class I2C:
//| """Two wire serial protocol"""
//|
//| def __init__(
//| self,
//| scl: microcontroller.Pin,
//| sda: microcontroller.Pin,
//| *,
//| frequency: int = 100000,
//| timeout: int = 255
//| ) -> None:
//| """I2C is a two-wire protocol for communicating between devices. At the
//| physical level it consists of 2 wires: SCL and SDA, the clock and data
//| lines respectively.
//|
//| .. seealso:: Using this class directly requires careful lock management.
//| Instead, use :class:`~adafruit_bus_device.I2CDevice` to
//| manage locks.
//|
//| .. seealso:: Using this class to directly read registers requires manual
//| bit unpacking. Instead, use an existing driver or make one with
//| :ref:`Register <register-module-reference>` data descriptors.
//|
//| :param ~microcontroller.Pin scl: The clock pin
//| :param ~microcontroller.Pin sda: The data pin
//| :param int frequency: The clock frequency in Hertz
//| :param int timeout: The maximum clock stretching timeut - (used only for
//| :class:`bitbangio.I2C`; ignored for :class:`busio.I2C`)
//| """
//| ...
STATIC mp_obj_t busio_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
busio_i2c_obj_t *self = mp_obj_malloc(busio_i2c_obj_t, &busio_i2c_type);
enum { ARG_scl, ARG_sda, ARG_frequency, ARG_timeout };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_scl, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_sda, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_frequency, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 100000} },
{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 255} },
};
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 *scl = validate_obj_is_free_pin(args[ARG_scl].u_obj, MP_QSTR_scl);
const mcu_pin_obj_t *sda = validate_obj_is_free_pin(args[ARG_sda].u_obj, MP_QSTR_sda);
common_hal_busio_i2c_construct(self, scl, sda, args[ARG_frequency].u_int, args[ARG_timeout].u_int);
return (mp_obj_t)self;
}
//| def deinit(self) -> None:
//| """Releases control of the underlying hardware so other classes can use it."""
//| ...
STATIC mp_obj_t busio_i2c_obj_deinit(mp_obj_t self_in) {
busio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
common_hal_busio_i2c_deinit(self);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_1(busio_i2c_deinit_obj, busio_i2c_obj_deinit);
STATIC void check_for_deinit(busio_i2c_obj_t *self) {
if (common_hal_busio_i2c_deinited(self)) {
raise_deinited_error();
}
}
//| def __enter__(self) -> I2C:
//| """No-op used in Context Managers."""
//| ...
// Provided by context manager helper.
//| def __exit__(self) -> None:
//| """Automatically deinitializes the hardware on context exit. See
//| :ref:`lifetime-and-contextmanagers` for more info."""
//| ...
STATIC mp_obj_t busio_i2c_obj___exit__(size_t n_args, const mp_obj_t *args) {
(void)n_args;
common_hal_busio_i2c_deinit(MP_OBJ_TO_PTR(args[0]));
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(busio_i2c___exit___obj, 4, 4, busio_i2c_obj___exit__);
static void check_lock(busio_i2c_obj_t *self) {
asm ("");
if (!common_hal_busio_i2c_has_lock(self)) {
mp_raise_RuntimeError(MP_ERROR_TEXT("Function requires lock"));
}
}
//| def scan(self) -> List[int]:
//| """Scan all I2C addresses between 0x08 and 0x77 inclusive and return a
//| list of those that respond.
//|
//| :return: List of device ids on the I2C bus
//| :rtype: list"""
//| ...
STATIC mp_obj_t busio_i2c_scan(mp_obj_t self_in) {
busio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
check_for_deinit(self);
check_lock(self);
mp_obj_t list = mp_obj_new_list(0, NULL);
// 7-bit addresses 0b0000xxx and 0b1111xxx are reserved
for (int addr = 0x08; addr < 0x78; ++addr) {
bool success = common_hal_busio_i2c_probe(self, addr);
if (success) {
mp_obj_list_append(list, MP_OBJ_NEW_SMALL_INT(addr));
}
}
return list;
}
MP_DEFINE_CONST_FUN_OBJ_1(busio_i2c_scan_obj, busio_i2c_scan);
//| def try_lock(self) -> bool:
//| """Attempts to grab the I2C lock. Returns True on success.
//|
//| :return: True when lock has been grabbed
//| :rtype: bool"""
//| ...
STATIC mp_obj_t busio_i2c_obj_try_lock(mp_obj_t self_in) {
busio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
check_for_deinit(self);
return mp_obj_new_bool(common_hal_busio_i2c_try_lock(self));
}
MP_DEFINE_CONST_FUN_OBJ_1(busio_i2c_try_lock_obj, busio_i2c_obj_try_lock);
//| def unlock(self) -> None:
//| """Releases the I2C lock."""
//| ...
STATIC mp_obj_t busio_i2c_obj_unlock(mp_obj_t self_in) {
busio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
check_for_deinit(self);
common_hal_busio_i2c_unlock(self);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_1(busio_i2c_unlock_obj, busio_i2c_obj_unlock);
//| import sys
//| def readfrom_into(
//| self, address: int, buffer: WriteableBuffer, *, start: int = 0, end: int = sys.maxsize
//| ) -> None:
//| """Read into ``buffer`` from the device selected by ``address``.
//| At least one byte must be read.
//|
//| If ``start`` or ``end`` is provided, then the buffer will be sliced
//| as if ``buffer[start:end]`` were passed, but without copying the data.
//| The number of bytes read will be the length of ``buffer[start:end]``.
//|
//| :param int address: 7-bit device address
//| :param WriteableBuffer buffer: buffer to write into
//| :param int start: beginning of buffer slice
//| :param int end: end of buffer slice; if not specified, use ``len(buffer)``"""
//| ...
STATIC mp_obj_t busio_i2c_readfrom_into(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_address, ARG_buffer, ARG_start, ARG_end };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_address, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
};
busio_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
check_for_deinit(self);
check_lock(self);
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_WRITE);
// Compute bounds in terms of elements, not bytes.
int stride_in_bytes = mp_binary_get_size('@', bufinfo.typecode, NULL);
size_t length = bufinfo.len / stride_in_bytes;
int32_t start = args[ARG_start].u_int;
const int32_t end = args[ARG_end].u_int;
normalize_buffer_bounds(&start, end, &length);
mp_arg_validate_length_min(length, 1, MP_QSTR_buffer);
// Treat start and length in terms of bytes from now on.
start *= stride_in_bytes;
length *= stride_in_bytes;
uint8_t status =
common_hal_busio_i2c_read(self, args[ARG_address].u_int, ((uint8_t *)bufinfo.buf) + start, length);
if (status != 0) {
mp_raise_OSError(status);
}
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_KW(busio_i2c_readfrom_into_obj, 1, busio_i2c_readfrom_into);
//| import sys
//| def writeto(
//| self, address: int, buffer: ReadableBuffer, *, start: int = 0, end: int = sys.maxsize
//| ) -> None:
//| """Write the bytes from ``buffer`` to the device selected by ``address`` and
//| then transmit a stop bit.
//|
//| If ``start`` or ``end`` is provided, then the buffer will be sliced
//| as if ``buffer[start:end]`` were passed, but without copying the data.
//| The number of bytes written will be the length of ``buffer[start:end]``.
//|
//| Writing a buffer or slice of length zero is permitted, as it can be used
//| to poll for the existence of a device.
//|
//| :param int address: 7-bit device address
//| :param ReadableBuffer buffer: buffer containing the bytes to write
//| :param int start: beginning of buffer slice
//| :param int end: end of buffer slice; if not specified, use ``len(buffer)``
//| """
//| ...
STATIC mp_obj_t busio_i2c_writeto(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_address, ARG_buffer, ARG_start, ARG_end };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_address, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
};
busio_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
check_for_deinit(self);
check_lock(self);
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
// get the buffer to write the data from
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_READ);
int stride_in_bytes = mp_binary_get_size('@', bufinfo.typecode, NULL);
// Compute bounds in terms of elements, not bytes.
size_t length = bufinfo.len / stride_in_bytes;
int32_t start = args[ARG_start].u_int;
const int32_t end = args[ARG_end].u_int;
normalize_buffer_bounds(&start, end, &length);
// Treat start and length in terms of bytes from now on.
start *= stride_in_bytes;
length *= stride_in_bytes;
// do the transfer
uint8_t status =
common_hal_busio_i2c_write(self, args[ARG_address].u_int, ((uint8_t *)bufinfo.buf) + start, length);
if (status != 0) {
mp_raise_OSError(status);
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(busio_i2c_writeto_obj, 1, busio_i2c_writeto);
//| import sys
//| def writeto_then_readfrom(
//| self,
//| address: int,
//| out_buffer: ReadableBuffer,
//| in_buffer: WriteableBuffer,
//| *,
//| out_start: int = 0,
//| out_end: int = sys.maxsize,
//| in_start: int = 0,
//| in_end: int = sys.maxsize
//| ) -> None:
//| """Write the bytes from ``out_buffer`` to the device selected by ``address``, generate no stop
//| bit, generate a repeated start and read into ``in_buffer``. ``out_buffer`` and
//| ``in_buffer`` can be the same buffer because they are used sequentially.
//|
//| If ``out_start`` or ``out_end`` is provided, then the buffer will be sliced
//| as if ``out_buffer[out_start:out_end]`` were passed, but without copying the data.
//| The number of bytes written will be the length of ``out_buffer[start:end]``.
//|
//| If ``in_start`` or ``in_end`` is provided, then the input buffer will be sliced
//| as if ``in_buffer[in_start:in_end]`` were passed,
//| The number of bytes read will be the length of ``out_buffer[in_start:in_end]``.
//|
//| :param int address: 7-bit device address
//| :param ~circuitpython_typing.ReadableBuffer out_buffer: buffer containing the bytes to write
//| :param ~circuitpython_typing.WriteableBuffer in_buffer: buffer to write into
//| :param int out_start: beginning of ``out_buffer`` slice
//| :param int out_end: end of ``out_buffer`` slice; if not specified, use ``len(out_buffer)``
//| :param int in_start: beginning of ``in_buffer`` slice
//| :param int in_end: end of ``in_buffer slice``; if not specified, use ``len(in_buffer)``
//| """
//| ...
//|
STATIC mp_obj_t busio_i2c_writeto_then_readfrom(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_address, ARG_out_buffer, ARG_in_buffer, ARG_out_start, ARG_out_end, ARG_in_start, ARG_in_end };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_address, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_out_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_in_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_out_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_out_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
{ MP_QSTR_in_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_in_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
};
busio_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
check_for_deinit(self);
check_lock(self);
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
mp_buffer_info_t out_bufinfo;
mp_get_buffer_raise(args[ARG_out_buffer].u_obj, &out_bufinfo, MP_BUFFER_READ);
int out_stride_in_bytes = mp_binary_get_size('@', out_bufinfo.typecode, NULL);
size_t out_length = out_bufinfo.len / out_stride_in_bytes;
int32_t out_start = args[ARG_out_start].u_int;
const int32_t out_end = args[ARG_out_end].u_int;
normalize_buffer_bounds(&out_start, out_end, &out_length);
mp_buffer_info_t in_bufinfo;
mp_get_buffer_raise(args[ARG_in_buffer].u_obj, &in_bufinfo, MP_BUFFER_WRITE);
int in_stride_in_bytes = mp_binary_get_size('@', in_bufinfo.typecode, NULL);
size_t in_length = in_bufinfo.len / in_stride_in_bytes;
int32_t in_start = args[ARG_in_start].u_int;
const int32_t in_end = args[ARG_in_end].u_int;
normalize_buffer_bounds(&in_start, in_end, &in_length);
mp_arg_validate_length_min(in_length, 1, MP_QSTR_out_buffer);
// Treat start and length in terms of bytes from now on.
out_start *= out_stride_in_bytes;
out_length *= out_stride_in_bytes;
in_start *= in_stride_in_bytes;
in_length *= in_stride_in_bytes;
uint8_t status = common_hal_busio_i2c_write_read(self, args[ARG_address].u_int,
((uint8_t *)out_bufinfo.buf) + out_start, out_length, ((uint8_t *)in_bufinfo.buf) + in_start, in_length);
if (status != 0) {
mp_raise_OSError(status);
}
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_KW(busio_i2c_writeto_then_readfrom_obj, 1, busio_i2c_writeto_then_readfrom);
STATIC const mp_rom_map_elem_t busio_i2c_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&busio_i2c_deinit_obj) },
{ MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
{ MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&busio_i2c___exit___obj) },
{ MP_ROM_QSTR(MP_QSTR_scan), MP_ROM_PTR(&busio_i2c_scan_obj) },
{ MP_ROM_QSTR(MP_QSTR_try_lock), MP_ROM_PTR(&busio_i2c_try_lock_obj) },
{ MP_ROM_QSTR(MP_QSTR_unlock), MP_ROM_PTR(&busio_i2c_unlock_obj) },
{ MP_ROM_QSTR(MP_QSTR_readfrom_into), MP_ROM_PTR(&busio_i2c_readfrom_into_obj) },
{ MP_ROM_QSTR(MP_QSTR_writeto), MP_ROM_PTR(&busio_i2c_writeto_obj) },
{ MP_ROM_QSTR(MP_QSTR_writeto_then_readfrom), MP_ROM_PTR(&busio_i2c_writeto_then_readfrom_obj) },
};
STATIC MP_DEFINE_CONST_DICT(busio_i2c_locals_dict, busio_i2c_locals_dict_table);
MP_DEFINE_CONST_OBJ_TYPE(
busio_i2c_type,
MP_QSTR_I2C,
MP_TYPE_FLAG_NONE,
make_new, busio_i2c_make_new,
locals_dict, &busio_i2c_locals_dict
);