altos: Add initial stm32l0 support

[fw/altos] / src / stm32l0 / ao_timer.c

diff --git a/src/stm32l0/ao_timer.c b/src/stm32l0/ao_timer.c
new file mode 100644 (file)
index 0000000..3b77afc
--- /dev/null
+++ b/src/stm32l0/ao_timer.c
@@ -0,0 +1,102 @@
+/*
+ * Copyright © 2020 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include "ao.h"
+#include <ao_task.h>
+#if HAS_FAKE_FLIGHT
+#include <ao_fake_flight.h>
+#endif
+
+#ifndef HAS_TICK
+#define HAS_TICK 1
+#endif
+
+#if HAS_TICK
+volatile AO_TICK_TYPE ao_tick_count;
+
+AO_TICK_TYPE
+ao_time(void)
+{
+       return ao_tick_count;
+}
+
+uint64_t
+ao_time_ns(void)
+{
+       AO_TICK_TYPE    before, after;
+       uint32_t        cvr;
+
+       do {
+               before = ao_tick_count;
+               cvr = stm_systick.cvr;
+               after = ao_tick_count;
+       } while (before != after);
+
+       return (uint64_t) after * (1000000000ULL / AO_HERTZ) +
+               (uint64_t) cvr * (1000000000ULL / AO_SYSTICK);
+}
+
+#if AO_DATA_ALL
+volatile uint8_t       ao_data_interval = 1;
+volatile uint8_t       ao_data_count;
+#endif
+
+void stm_systick_isr(void)
+{
+       if (stm_systick.csr & (1 << STM_SYSTICK_CSR_COUNTFLAG)) {
+               ++ao_tick_count;
+#if HAS_TASK_QUEUE
+               if (ao_task_alarm_tick && (int16_t) (ao_tick_count - ao_task_alarm_tick) >= 0)
+                       ao_task_check_alarm((uint16_t) ao_tick_count);
+#endif
+#if AO_DATA_ALL
+               if (++ao_data_count == ao_data_interval) {
+                       ao_data_count = 0;
+#if HAS_ADC
+#if HAS_FAKE_FLIGHT
+                       if (ao_fake_flight_active)
+                               ao_fake_flight_poll();
+                       else
+#endif
+                               ao_adc_poll();
+#endif
+#if (AO_DATA_ALL & ~(AO_DATA_ADC))
+                       ao_wakeup((void *) &ao_data_count);
+#endif
+               }
+#endif
+#ifdef AO_TIMER_HOOK
+               AO_TIMER_HOOK;
+#endif
+       }
+}
+
+#define SYSTICK_RELOAD (AO_SYSTICK / 100 - 1)
+
+void
+ao_timer_init(void)
+{
+       stm_systick.csr = 0;
+       stm_systick.rvr = SYSTICK_RELOAD;
+       stm_systick.cvr = 0;
+       stm_systick.csr = ((1 << STM_SYSTICK_CSR_ENABLE) |
+                          (1 << STM_SYSTICK_CSR_TICKINT) |
+                          (STM_SYSTICK_CSR_CLKSOURCE_HCLK_8 << STM_SYSTICK_CSR_CLKSOURCE));
+}
+
+#endif