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       1                 :            : /*
       2                 :            :  * This file is part of the MicroPython project, http://micropython.org/
       3                 :            :  *
       4                 :            :  * The MIT License (MIT)
       5                 :            :  *
       6                 :            :  * Copyright (c) 2016 Damien P. George
       7                 :            :  *
       8                 :            :  * Permission is hereby granted, free of charge, to any person obtaining a copy
       9                 :            :  * of this software and associated documentation files (the "Software"), to deal
      10                 :            :  * in the Software without restriction, including without limitation the rights
      11                 :            :  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
      12                 :            :  * copies of the Software, and to permit persons to whom the Software is
      13                 :            :  * furnished to do so, subject to the following conditions:
      14                 :            :  *
      15                 :            :  * The above copyright notice and this permission notice shall be included in
      16                 :            :  * all copies or substantial portions of the Software.
      17                 :            :  *
      18                 :            :  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      19                 :            :  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      20                 :            :  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
      21                 :            :  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
      22                 :            :  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
      23                 :            :  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
      24                 :            :  * THE SOFTWARE.
      25                 :            :  */
      26                 :            : 
      27                 :            : #include "py/runtime.h"
      28                 :            : #include "py/mperrno.h"
      29                 :            : #include "extmod/modmachine.h"
      30                 :            : 
      31                 :            : #if MICROPY_PY_MACHINE_PULSE
      32                 :            : 
      33                 :          8 : MP_WEAK mp_uint_t machine_time_pulse_us(mp_hal_pin_obj_t pin, int pulse_level, mp_uint_t timeout_us) {
      34                 :          8 :     mp_uint_t start = mp_hal_ticks_us();
      35         [ +  + ]:        126 :     while (mp_hal_pin_read(pin) != pulse_level) {
      36         [ +  + ]:        120 :         if ((mp_uint_t)(mp_hal_ticks_us() - start) >= timeout_us) {
      37                 :            :             return (mp_uint_t)-2;
      38                 :            :         }
      39                 :            :     }
      40                 :          6 :     start = mp_hal_ticks_us();
      41         [ +  + ]:        119 :     while (mp_hal_pin_read(pin) == pulse_level) {
      42         [ +  + ]:        115 :         if ((mp_uint_t)(mp_hal_ticks_us() - start) >= timeout_us) {
      43                 :            :             return (mp_uint_t)-1;
      44                 :            :         }
      45                 :            :     }
      46                 :          4 :     return mp_hal_ticks_us() - start;
      47                 :            : }
      48                 :            : 
      49                 :          8 : static mp_obj_t machine_time_pulse_us_(size_t n_args, const mp_obj_t *args) {
      50                 :          8 :     mp_hal_pin_obj_t pin = mp_hal_get_pin_obj(args[0]);
      51                 :          8 :     int level = 0;
      52         [ +  + ]:          8 :     if (mp_obj_is_true(args[1])) {
      53                 :          4 :         level = 1;
      54                 :            :     }
      55                 :          8 :     mp_uint_t timeout_us = 1000000;
      56         [ +  + ]:          8 :     if (n_args > 2) {
      57                 :          4 :         timeout_us = mp_obj_get_int(args[2]);
      58                 :            :     }
      59                 :          8 :     mp_uint_t us = machine_time_pulse_us(pin, level, timeout_us);
      60                 :            :     // May return -1 or -2 in case of timeout
      61                 :          8 :     return mp_obj_new_int(us);
      62                 :            : }
      63                 :            : MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_time_pulse_us_obj, 2, 3, machine_time_pulse_us_);
      64                 :            : 
      65                 :            : #endif