2 * Copyright © 2023 Keith Packard <keithp@keithp.com>
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.
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.
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.
26 volatile AO_TICK_TYPE ao_tick_count;
37 AO_TICK_TYPE before, after;
41 before = ao_tick_count;
42 val = stm_systick.val;
43 after = ao_tick_count;
44 } while (before != after);
46 return (uint64_t) after * (1000000000ULL / AO_HERTZ) +
47 (uint64_t) val * (1000000000ULL / AO_SYSTICK);
50 void stm_systick_isr(void)
52 if (stm_systick.ctrl & (1 << STM_SYSTICK_CTRL_COUNTFLAG)) {
54 ao_task_check_alarm();
61 #define SYSTICK_RELOAD (AO_SYSTICK / 100 - 1)
66 stm_systick.load = SYSTICK_RELOAD;
68 stm_systick.ctrl = ((1 << STM_SYSTICK_CTRL_ENABLE) |
69 (1 << STM_SYSTICK_CTRL_TICKINT) |
70 (STM_SYSTICK_CTRL_CLKSOURCE_HCLK_8 << STM_SYSTICK_CTRL_CLKSOURCE));
71 stm_scb.shpr3 |= (uint32_t) AO_STM_NVIC_CLOCK_PRIORITY << 24;