diff options
author | Raghuram Subramani <raghus2247@gmail.com> | 2022-06-19 19:47:51 +0530 |
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committer | Raghuram Subramani <raghus2247@gmail.com> | 2022-06-19 19:47:51 +0530 |
commit | 4fd287655a72b9aea14cdac715ad5b90ed082ed2 (patch) | |
tree | 65d393bc0e699dd12d05b29ba568e04cea666207 /circuitpython/shared-bindings/bitbangio/I2C.c | |
parent | 0150f70ce9c39e9e6dd878766c0620c85e47bed0 (diff) |
add circuitpython code
Diffstat (limited to 'circuitpython/shared-bindings/bitbangio/I2C.c')
-rw-r--r-- | circuitpython/shared-bindings/bitbangio/I2C.c | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/circuitpython/shared-bindings/bitbangio/I2C.c b/circuitpython/shared-bindings/bitbangio/I2C.c new file mode 100644 index 0000000..c65b184 --- /dev/null +++ b/circuitpython/shared-bindings/bitbangio/I2C.c @@ -0,0 +1,351 @@ +/* + * 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 +// bitbangio.I2C class. + +#include "shared-bindings/bitbangio/I2C.h" +#include "shared-bindings/microcontroller/Pin.h" +#include "shared-bindings/util.h" + +#include "shared/runtime/buffer_helper.h" +#include "shared/runtime/context_manager_helpers.h" +#include "py/mperrno.h" +#include "py/runtime.h" +#include "supervisor/shared/translate.h" + +//| class I2C: +//| """Two wire serial protocol""" +//| +//| def __init__(self, scl: microcontroller.Pin, sda: microcontroller.Pin, *, frequency: int = 400000, 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.i2c_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 of the bus +//| :param int timeout: The maximum clock stretching timeout in microseconds""" +//| ... +//| +STATIC mp_obj_t bitbangio_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) { + 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 = 400000} }, + { 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); + const mcu_pin_obj_t *sda = validate_obj_is_free_pin(args[ARG_sda].u_obj); + + bitbangio_i2c_obj_t *self = m_new_obj(bitbangio_i2c_obj_t); + self->base.type = &bitbangio_i2c_type; + shared_module_bitbangio_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 bitbangio_i2c_obj_deinit(mp_obj_t self_in) { + bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); + shared_module_bitbangio_i2c_deinit(self); + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_i2c_deinit_obj, bitbangio_i2c_obj_deinit); + +STATIC void check_for_deinit(bitbangio_i2c_obj_t *self) { + if (shared_module_bitbangio_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 bitbangio_i2c_obj___exit__(size_t n_args, const mp_obj_t *args) { + (void)n_args; + shared_module_bitbangio_i2c_deinit(args[0]); + return mp_const_none; +} +STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(bitbangio_i2c_obj___exit___obj, 4, 4, bitbangio_i2c_obj___exit__); + +static void check_lock(bitbangio_i2c_obj_t *self) { + if (!shared_module_bitbangio_i2c_has_lock(self)) { + mp_raise_RuntimeError(translate("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. A device responds if it pulls the SDA line low after +//| its address (including a read bit) is sent on the bus.""" +//| ... +//| +STATIC mp_obj_t bitbangio_i2c_scan(mp_obj_t self_in) { + bitbangio_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 = shared_module_bitbangio_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(bitbangio_i2c_scan_obj, bitbangio_i2c_scan); + +//| def try_lock(self) -> bool: +//| """Attempts to grab the I2C lock. Returns True on success.""" +//| ... +//| +STATIC mp_obj_t bitbangio_i2c_obj_try_lock(mp_obj_t self_in) { + bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); + check_for_deinit(self); + return mp_obj_new_bool(shared_module_bitbangio_i2c_try_lock(self)); +} +MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_i2c_try_lock_obj, bitbangio_i2c_obj_try_lock); + +//| def unlock(self) -> None: +//| """Releases the I2C lock.""" +//| ... +//| +STATIC mp_obj_t bitbangio_i2c_obj_unlock(mp_obj_t self_in) { + bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); + check_for_deinit(self); + shared_module_bitbangio_i2c_unlock(self); + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_i2c_unlock_obj, bitbangio_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``. +//| The number of bytes read will be the length of ``buffer``. +//| At least one byte must be read. +//| +//| If ``start`` or ``end`` is provided, then the buffer will be sliced +//| as if ``buffer[start:end]``. This will not cause an allocation like +//| ``buf[start:end]`` will so it saves memory. +//| +//| :param int address: 7-bit device address +//| :param WriteableBuffer buffer: buffer to write into +//| :param int start: Index to start writing at +//| :param int end: Index to write up to but not include""" +//| ... +//| +// Shared arg parsing for readfrom_into and writeto_then_readfrom. +STATIC void readfrom(bitbangio_i2c_obj_t *self, mp_int_t address, mp_obj_t buffer, int32_t start, mp_int_t end) { + mp_buffer_info_t bufinfo; + mp_get_buffer_raise(buffer, &bufinfo, MP_BUFFER_WRITE); + + size_t length = bufinfo.len; + normalize_buffer_bounds(&start, end, &length); + if (length == 0) { + mp_raise_ValueError(translate("Buffer must be at least length 1")); + } + + uint8_t status = shared_module_bitbangio_i2c_read(self, address, ((uint8_t *)bufinfo.buf) + start, length); + if (status != 0) { + mp_raise_OSError(status); + } +} + +STATIC mp_obj_t bitbangio_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} }, + }; + bitbangio_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); + + readfrom(self, args[ARG_address].u_int, args[ARG_buffer].u_obj, args[ARG_start].u_int, + args[ARG_end].u_int); + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_KW(bitbangio_i2c_readfrom_into_obj, 1, bitbangio_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 transmits a +//| stop bit. Use `writeto_then_readfrom` when needing a write, no stop and repeated start +//| before a 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 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)`` +//| """ +//| ... +//| +// Shared arg parsing for writeto and writeto_then_readfrom. +STATIC void writeto(bitbangio_i2c_obj_t *self, mp_int_t address, mp_obj_t buffer, int32_t start, mp_int_t end, bool stop) { + // get the buffer to write the data from + mp_buffer_info_t bufinfo; + mp_get_buffer_raise(buffer, &bufinfo, MP_BUFFER_READ); + + size_t length = bufinfo.len; + normalize_buffer_bounds(&start, end, &length); + + // do the transfer + uint8_t status = shared_module_bitbangio_i2c_write(self, address, + ((uint8_t *)bufinfo.buf) + start, length, + stop); + if (status != 0) { + mp_raise_OSError(status); + } +} + +STATIC mp_obj_t bitbangio_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} }, + }; + bitbangio_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); + + writeto(self, args[ARG_address].u_int, args[ARG_buffer].u_obj, args[ARG_start].u_int, + args[ARG_end].u_int, true); + return mp_const_none; +} +STATIC MP_DEFINE_CONST_FUN_OBJ_KW(bitbangio_i2c_writeto_obj, 1, bitbangio_i2c_writeto); + + +//| import sys +//| def writeto_then_readfrom(self, address: int, out_buffer: ReadableBuffer, in_buffer: ReadableBuffer, *, 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 bitbangio_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} }, + }; + bitbangio_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); + + writeto(self, args[ARG_address].u_int, args[ARG_out_buffer].u_obj, args[ARG_out_start].u_int, + args[ARG_out_end].u_int, false); + readfrom(self, args[ARG_address].u_int, args[ARG_in_buffer].u_obj, args[ARG_in_start].u_int, + args[ARG_in_end].u_int); + + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_KW(bitbangio_i2c_writeto_then_readfrom_obj, 1, bitbangio_i2c_writeto_then_readfrom); + +STATIC const mp_rom_map_elem_t bitbangio_i2c_locals_dict_table[] = { + { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&bitbangio_i2c_deinit_obj) }, + { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) }, + { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&bitbangio_i2c_obj___exit___obj) }, + { MP_ROM_QSTR(MP_QSTR_scan), MP_ROM_PTR(&bitbangio_i2c_scan_obj) }, + + { MP_ROM_QSTR(MP_QSTR_try_lock), MP_ROM_PTR(&bitbangio_i2c_try_lock_obj) }, + { MP_ROM_QSTR(MP_QSTR_unlock), MP_ROM_PTR(&bitbangio_i2c_unlock_obj) }, + + { MP_ROM_QSTR(MP_QSTR_writeto), MP_ROM_PTR(&bitbangio_i2c_writeto_obj) }, + { MP_ROM_QSTR(MP_QSTR_readfrom_into), MP_ROM_PTR(&bitbangio_i2c_readfrom_into_obj) }, + { MP_ROM_QSTR(MP_QSTR_writeto_then_readfrom), MP_ROM_PTR(&bitbangio_i2c_writeto_then_readfrom_obj) }, +}; + +STATIC MP_DEFINE_CONST_DICT(bitbangio_i2c_locals_dict, bitbangio_i2c_locals_dict_table); + +const mp_obj_type_t bitbangio_i2c_type = { + { &mp_type_type }, + .name = MP_QSTR_I2C, + .make_new = bitbangio_i2c_make_new, + .locals_dict = (mp_obj_dict_t *)&bitbangio_i2c_locals_dict, +}; |