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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 uint64_t
  39 ao_time_ns(void)
  40 {
  41         AO_TICK_TYPE    before, after;
  42         uint32_t        cvr;
  43
  44         do {
  45                 before = ao_tick_count;
  46                 cvr = stm_systick.cvr;
  47                 after = ao_tick_count;
  48         } while (before != after);
  49
  50         return (uint64_t) after * (1000000000ULL / AO_HERTZ) +
  51                 (uint64_t) cvr * (1000000000ULL / AO_SYSTICK);
  52 }
  53
  54 #if AO_DATA_ALL
  55 volatile uint8_t        ao_data_interval = 1;
  56 volatile uint8_t        ao_data_count;
  57 #endif
  58
  59 void stm_systick_isr(void)
  60 {
  61         if (stm_systick.csr & (1 << STM_SYSTICK_CSR_COUNTFLAG)) {
  62                 ++ao_tick_count;
  63 #if HAS_TASK_QUEUE
  64                 if (ao_task_alarm_tick && (int16_t) (ao_tick_count - ao_task_alarm_tick) >= 0)
  65                         ao_task_check_alarm((uint16_t) ao_tick_count);
  66 #endif
  67 #if AO_DATA_ALL
  68                 if (++ao_data_count == ao_data_interval) {
  69                         ao_data_count = 0;
  70 #if HAS_ADC
  71 #if HAS_FAKE_FLIGHT
  72                         if (ao_fake_flight_active)
  73                                 ao_fake_flight_poll();
  74                         else
  75 #endif
  76                                 ao_adc_poll();
  77 #endif
  78 #if (AO_DATA_ALL & ~(AO_DATA_ADC))
  79                         ao_wakeup((void *) &ao_data_count);
  80 #endif
  81                 }
  82 #endif
  83 #ifdef AO_TIMER_HOOK
  84                 AO_TIMER_HOOK;
  85 #endif
  86         }
  87 }
  88
  89 #define SYSTICK_RELOAD (AO_SYSTICK / 100 - 1)
  90
  91 void
  92 ao_timer_init(void)
  93 {
  94         stm_systick.csr = 0;
  95         stm_systick.rvr = SYSTICK_RELOAD;
  96         stm_systick.cvr = 0;
  97         stm_systick.csr = ((1 << STM_SYSTICK_CSR_ENABLE) |
  98                            (1 << STM_SYSTICK_CSR_TICKINT) |
  99                            (STM_SYSTICK_CSR_CLKSOURCE_HCLK_8 << STM_SYSTICK_CSR_CLKSOURCE));
 100 }
 101
 102 #endif