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   1 /*
   2  * Copyright © 2020 Keith Packard <keithp@keithp.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  17  */
  18
  19 #include "ao.h"
  20 #include <ao_task.h>
  21 #if HAS_FAKE_FLIGHT
  22 #include <ao_fake_flight.h>
  23 #endif
  24
  25 #ifndef HAS_TICK
  26 #define HAS_TICK 1
  27 #endif
  28
  29 #if HAS_TICK
  30 volatile AO_TICK_TYPE ao_tick_count;
  31
  32 AO_TICK_TYPE
  33 ao_time(void)
  34 {
  35         return ao_tick_count;
  36 }
  37
  38 #if 0
  39 uint64_t
  40 ao_time_ns(void)
  41 {
  42         AO_TICK_TYPE    before, after;
  43         uint32_t        cvr;
  44
  45         do {
  46                 before = ao_tick_count;
  47                 cvr = stm_systick.cvr;
  48                 after = ao_tick_count;
  49         } while (before != after);
  50
  51         return (uint64_t) after * (1000000000ULL / AO_HERTZ) +
  52                 (uint64_t) cvr * (1000000000ULL / AO_SYSTICK);
  53 }
  54 #endif
  55
  56 #if AO_DATA_ALL
  57 volatile uint8_t        ao_data_interval = 1;
  58 volatile uint8_t        ao_data_count;
  59 #endif
  60
  61 void stm_systick_isr(void)
  62 {
  63         if (stm_systick.csr & (1 << STM_SYSTICK_CSR_COUNTFLAG)) {
  64                 ++ao_tick_count;
  65                 ao_task_check_alarm();
  66 #if AO_DATA_ALL
  67                 if (++ao_data_count == ao_data_interval) {
  68                         ao_data_count = 0;
  69 #if HAS_ADC
  70 #if HAS_FAKE_FLIGHT
  71                         if (ao_fake_flight_active)
  72                                 ao_fake_flight_poll();
  73                         else
  74 #endif
  75                                 ao_adc_poll();
  76 #endif
  77 #if (AO_DATA_ALL & ~(AO_DATA_ADC))
  78                         ao_wakeup((void *) &ao_data_count);
  79 #endif
  80                 }
  81 #endif
  82 #ifdef AO_TIMER_HOOK
  83                 AO_TIMER_HOOK;
  84 #endif
  85         }
  86 }
  87
  88 #define SYSTICK_RELOAD (AO_SYSTICK / 100 - 1)
  89
  90 void
  91 ao_timer_init(void)
  92 {
  93         stm_systick.csr = 0;
  94         stm_systick.rvr = SYSTICK_RELOAD;
  95         stm_systick.cvr = 0;
  96         stm_systick.csr = ((1 << STM_SYSTICK_CSR_ENABLE) |
  97                            (1 << STM_SYSTICK_CSR_TICKINT) |
  98                            (STM_SYSTICK_CSR_CLKSOURCE_HCLK_8 << STM_SYSTICK_CSR_CLKSOURCE));
  99 }
 100
 101 void
 102 ao_timer_stop(void)
 103 {
 104         stm_systick.csr = 0;
 105 }
 106
 107 #endif