350 lines
16 KiB
C
350 lines
16 KiB
C
/*
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* This file is part of the MicroPython project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2016 Scott Shawcroft
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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// This file contains all of the Python API definitions for the
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// busio.I2C class.
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#include "shared-bindings/microcontroller/Pin.h"
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#include "shared-bindings/busio/I2C.h"
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#include "shared-bindings/util.h"
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#include "lib/utils/buffer_helper.h"
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#include "lib/utils/context_manager_helpers.h"
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#include "py/runtime.h"
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#include "supervisor/shared/translate.h"
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//| class I2C:
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//| """Two wire serial protocol"""
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//|
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//| def __init__(self, scl: microcontroller.Pin, sda: microcontroller.Pin, *, frequency: int = 400000, timeout: int = 255) -> None:
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//|
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//| """I2C is a two-wire protocol for communicating between devices. At the
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//| physical level it consists of 2 wires: SCL and SDA, the clock and data
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//| lines respectively.
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//|
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//| .. seealso:: Using this class directly requires careful lock management.
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//| Instead, use :class:`~adafruit_bus_device.i2c_device.I2CDevice` to
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//| manage locks.
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//|
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//| .. seealso:: Using this class to directly read registers requires manual
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//| bit unpacking. Instead, use an existing driver or make one with
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//| :ref:`Register <register-module-reference>` data descriptors.
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//|
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//| :param ~microcontroller.Pin scl: The clock pin
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//| :param ~microcontroller.Pin sda: The data pin
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//| :param int frequency: The clock frequency in Hertz
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//| :param int timeout: The maximum clock stretching timeut - (used only for bitbangio.I2C; ignored for busio.I2C)
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//|
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//| .. note:: On the nRF52840, only one I2C object may be created,
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//| except on the Circuit Playground Bluefruit, which allows two,
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//| one for the onboard accelerometer, and one for offboard use."""
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//| ...
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//|
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STATIC mp_obj_t busio_i2c_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
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busio_i2c_obj_t *self = m_new_obj(busio_i2c_obj_t);
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self->base.type = &busio_i2c_type;
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enum { ARG_scl, ARG_sda, ARG_frequency, ARG_timeout };
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static const mp_arg_t allowed_args[] = {
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{ MP_QSTR_scl, MP_ARG_REQUIRED | MP_ARG_OBJ },
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{ MP_QSTR_sda, MP_ARG_REQUIRED | MP_ARG_OBJ },
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{ MP_QSTR_frequency, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} },
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{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 255} },
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};
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mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
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mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
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const mcu_pin_obj_t* scl = validate_obj_is_free_pin(args[ARG_scl].u_obj);
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const mcu_pin_obj_t* sda = validate_obj_is_free_pin(args[ARG_sda].u_obj);
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common_hal_busio_i2c_construct(self, scl, sda, args[ARG_frequency].u_int, args[ARG_timeout].u_int);
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return (mp_obj_t)self;
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}
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//| def deinit(self) -> None:
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//| """Releases control of the underlying hardware so other classes can use it."""
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//| ...
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//|
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STATIC mp_obj_t busio_i2c_obj_deinit(mp_obj_t self_in) {
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busio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
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common_hal_busio_i2c_deinit(self);
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return mp_const_none;
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}
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MP_DEFINE_CONST_FUN_OBJ_1(busio_i2c_deinit_obj, busio_i2c_obj_deinit);
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STATIC void check_for_deinit(busio_i2c_obj_t *self) {
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if (common_hal_busio_i2c_deinited(self)) {
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raise_deinited_error();
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}
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}
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//| def __enter__(self) -> I2C:
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//| """No-op used in Context Managers."""
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//| ...
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//|
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// Provided by context manager helper.
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//| def __exit__(self) -> None:
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//| """Automatically deinitializes the hardware on context exit. See
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//| :ref:`lifetime-and-contextmanagers` for more info."""
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//| ...
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//|
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STATIC mp_obj_t busio_i2c_obj___exit__(size_t n_args, const mp_obj_t *args) {
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(void)n_args;
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common_hal_busio_i2c_deinit(args[0]);
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return mp_const_none;
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(busio_i2c___exit___obj, 4, 4, busio_i2c_obj___exit__);
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static void check_lock(busio_i2c_obj_t *self) {
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asm("");
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if (!common_hal_busio_i2c_has_lock(self)) {
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mp_raise_RuntimeError(translate("Function requires lock"));
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}
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}
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//| def scan(self) -> List[int]:
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//| """Scan all I2C addresses between 0x08 and 0x77 inclusive and return a
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//| list of those that respond.
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//|
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//| :return: List of device ids on the I2C bus
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//| :rtype: list"""
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//| ...
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//|
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STATIC mp_obj_t busio_i2c_scan(mp_obj_t self_in) {
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busio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
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check_for_deinit(self);
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check_lock(self);
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mp_obj_t list = mp_obj_new_list(0, NULL);
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// 7-bit addresses 0b0000xxx and 0b1111xxx are reserved
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for (int addr = 0x08; addr < 0x78; ++addr) {
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bool success = common_hal_busio_i2c_probe(self, addr);
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if (success) {
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mp_obj_list_append(list, MP_OBJ_NEW_SMALL_INT(addr));
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}
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}
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return list;
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}
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MP_DEFINE_CONST_FUN_OBJ_1(busio_i2c_scan_obj, busio_i2c_scan);
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//| def try_lock(self) -> bool:
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//| """Attempts to grab the I2C lock. Returns True on success.
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//|
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//| :return: True when lock has been grabbed
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//| :rtype: bool"""
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//| ...
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//|
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STATIC mp_obj_t busio_i2c_obj_try_lock(mp_obj_t self_in) {
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busio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
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check_for_deinit(self);
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return mp_obj_new_bool(common_hal_busio_i2c_try_lock(self));
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}
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MP_DEFINE_CONST_FUN_OBJ_1(busio_i2c_try_lock_obj, busio_i2c_obj_try_lock);
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//| def unlock(self) -> None:
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//| """Releases the I2C lock."""
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//| ...
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//|
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STATIC mp_obj_t busio_i2c_obj_unlock(mp_obj_t self_in) {
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busio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
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check_for_deinit(self);
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common_hal_busio_i2c_unlock(self);
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return mp_const_none;
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}
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MP_DEFINE_CONST_FUN_OBJ_1(busio_i2c_unlock_obj, busio_i2c_obj_unlock);
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//| def readfrom_into(self, address: int, buffer: WriteableBuffer, *, start: int = 0, end: Optional[int] = None) -> None:
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//| """Read into ``buffer`` from the device selected by ``address``.
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//| The number of bytes read will be the length of ``buffer``.
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//| At least one byte must be read.
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//|
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//| If ``start`` or ``end`` is provided, then the buffer will be sliced
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//| as if ``buffer[start:end]``. This will not cause an allocation like
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//| ``buf[start:end]`` will so it saves memory.
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//|
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//| :param int address: 7-bit device address
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//| :param ~_typing.WriteableBuffer buffer: buffer to write into
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//| :param int start: Index to start writing at
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//| :param int end: Index to write up to but not include. Defaults to ``len(buffer)``"""
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//| ...
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//|
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// Shared arg parsing for readfrom_into and writeto_then_readfrom.
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STATIC void readfrom(busio_i2c_obj_t *self, mp_int_t address, mp_obj_t buffer, int32_t start, mp_int_t end) {
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mp_buffer_info_t bufinfo;
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mp_get_buffer_raise(buffer, &bufinfo, MP_BUFFER_WRITE);
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size_t length = bufinfo.len;
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normalize_buffer_bounds(&start, end, &length);
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if (length == 0) {
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mp_raise_ValueError(translate("Buffer must be at least length 1"));
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}
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uint8_t status = common_hal_busio_i2c_read(self, address, ((uint8_t*)bufinfo.buf) + start, length);
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if (status != 0) {
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mp_raise_OSError(status);
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}
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}
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STATIC mp_obj_t busio_i2c_readfrom_into(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
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enum { ARG_address, ARG_buffer, ARG_start, ARG_end };
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static const mp_arg_t allowed_args[] = {
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{ MP_QSTR_address, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
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{ MP_QSTR_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
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{ MP_QSTR_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
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{ MP_QSTR_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
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};
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busio_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
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check_for_deinit(self);
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check_lock(self);
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mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
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mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
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readfrom(self, args[ARG_address].u_int, args[ARG_buffer].u_obj, args[ARG_start].u_int,
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args[ARG_end].u_int);
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return mp_const_none;
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}
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MP_DEFINE_CONST_FUN_OBJ_KW(busio_i2c_readfrom_into_obj, 3, busio_i2c_readfrom_into);
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//| def writeto(self, address: int, buffer: ReadableBuffer, *, start: int = 0, end: Optional[int] = None, stop: bool = True) -> None:
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//| """Write the bytes from ``buffer`` to the device selected by ``address`` and
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//| then transmit a stop bit.
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//|
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//| If ``start`` or ``end`` is provided, then the buffer will be sliced
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//| as if ``buffer[start:end]``. This will not cause an allocation like
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//| ``buffer[start:end]`` will so it saves memory.
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//|
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//| Writing a buffer or slice of length zero is permitted, as it can be used
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//| to poll for the existence of a device.
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//|
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//| :param int address: 7-bit device address
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//| :param ~_typing.ReadbleBuffer buffer: buffer containing the bytes to write
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//| :param int start: Index to start writing from
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//| :param int end: Index to read up to but not include. Defaults to ``len(buffer)``"""
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//| ...
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//|
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// Shared arg parsing for writeto and writeto_then_readfrom.
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STATIC void writeto(busio_i2c_obj_t *self, mp_int_t address, mp_obj_t buffer, int32_t start, mp_int_t end, bool stop) {
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// get the buffer to write the data from
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mp_buffer_info_t bufinfo;
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mp_get_buffer_raise(buffer, &bufinfo, MP_BUFFER_READ);
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size_t length = bufinfo.len;
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normalize_buffer_bounds(&start, end, &length);
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// do the transfer
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uint8_t status = common_hal_busio_i2c_write(self, address, ((uint8_t*) bufinfo.buf) + start,
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length, stop);
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if (status != 0) {
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mp_raise_OSError(status);
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}
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}
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STATIC mp_obj_t busio_i2c_writeto(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
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enum { ARG_address, ARG_buffer, ARG_start, ARG_end };
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static const mp_arg_t allowed_args[] = {
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{ MP_QSTR_address, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
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{ MP_QSTR_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
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{ MP_QSTR_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
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{ MP_QSTR_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
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};
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busio_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
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check_for_deinit(self);
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check_lock(self);
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mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
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mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
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writeto(self, args[ARG_address].u_int, args[ARG_buffer].u_obj, args[ARG_start].u_int,
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args[ARG_end].u_int, true);
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return mp_const_none;
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_KW(busio_i2c_writeto_obj, 1, busio_i2c_writeto);
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//| def writeto_then_readfrom(self, address: int, out_buffer: ReadableBuffer, in_buffer: WriteableBuffer, *, out_start: int = 0, out_end: Optional[int] = None, in_start: int = 0, in_end: Optional[int] = None) -> None:
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//| """Write the bytes from ``out_buffer`` to the device selected by ``address``, generate no stop
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//| bit, generate a repeated start and read into ``in_buffer``. ``out_buffer`` and
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//| ``in_buffer`` can be the same buffer because they are used sequentially.
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//|
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//| if ``start`` or ``end`` is provided, then the corresponding buffer will be sliced
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//| as if ``buffer[start:end]``. This will not cause an allocation like ``buf[start:end]``
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//| will so it saves memory.
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//|
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//| :param int address: 7-bit device address
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//| :param ~_typing.ReadbleBuffer out_buffer: buffer containing the bytes to write
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//| :param ~_typing.WriteableBuffer in_buffer: buffer to write into
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//| :param int out_start: Index to start writing from
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//| :param int out_end: Index to read up to but not include. Defaults to ``len(buffer)``
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//| :param int in_start: Index to start writing at
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//| :param int in_end: Index to write up to but not include. Defaults to ``len(buffer)``"""
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//| ...
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//|
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STATIC mp_obj_t busio_i2c_writeto_then_readfrom(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
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enum { ARG_address, ARG_out_buffer, ARG_in_buffer, ARG_out_start, ARG_out_end, ARG_in_start, ARG_in_end };
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static const mp_arg_t allowed_args[] = {
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{ MP_QSTR_address, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
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{ MP_QSTR_out_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
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{ MP_QSTR_in_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
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{ MP_QSTR_out_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
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{ MP_QSTR_out_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
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{ MP_QSTR_in_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
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{ MP_QSTR_in_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
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};
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busio_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
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check_for_deinit(self);
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check_lock(self);
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mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
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mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
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writeto(self, args[ARG_address].u_int, args[ARG_out_buffer].u_obj, args[ARG_out_start].u_int,
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args[ARG_out_end].u_int, false);
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readfrom(self, args[ARG_address].u_int, args[ARG_in_buffer].u_obj, args[ARG_in_start].u_int,
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args[ARG_in_end].u_int);
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return mp_const_none;
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}
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MP_DEFINE_CONST_FUN_OBJ_KW(busio_i2c_writeto_then_readfrom_obj, 3, busio_i2c_writeto_then_readfrom);
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STATIC const mp_rom_map_elem_t busio_i2c_locals_dict_table[] = {
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{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&busio_i2c_deinit_obj) },
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{ MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
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{ MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&busio_i2c___exit___obj) },
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{ MP_ROM_QSTR(MP_QSTR_scan), MP_ROM_PTR(&busio_i2c_scan_obj) },
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{ MP_ROM_QSTR(MP_QSTR_try_lock), MP_ROM_PTR(&busio_i2c_try_lock_obj) },
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{ MP_ROM_QSTR(MP_QSTR_unlock), MP_ROM_PTR(&busio_i2c_unlock_obj) },
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{ MP_ROM_QSTR(MP_QSTR_readfrom_into), MP_ROM_PTR(&busio_i2c_readfrom_into_obj) },
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{ MP_ROM_QSTR(MP_QSTR_writeto), MP_ROM_PTR(&busio_i2c_writeto_obj) },
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{ MP_ROM_QSTR(MP_QSTR_writeto_then_readfrom), MP_ROM_PTR(&busio_i2c_writeto_then_readfrom_obj) },
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};
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STATIC MP_DEFINE_CONST_DICT(busio_i2c_locals_dict, busio_i2c_locals_dict_table);
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const mp_obj_type_t busio_i2c_type = {
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{ &mp_type_type },
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.name = MP_QSTR_I2C,
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.make_new = busio_i2c_make_new,
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.locals_dict = (mp_obj_dict_t*)&busio_i2c_locals_dict,
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};
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