1 files changed, 137 insertions, 0 deletions
diff --git a/cm3cpp/systick.cpp b/cm3cpp/systick.cpp
new file mode 100644
index 0000000..5e1c0e5
--- /dev/null
+++ b/cm3cpp/systick.cpp
@@ -0,0 +1,137 @@
+/*
+ * This file is part of the libopencm3_cpp_extensions project.
+ * hosted at http://github.com/thirdpin/libopencm3_cpp_extensions
+ *
+ * Copyright (C) 2016  Third Pin LLC
+ * Written by Anastasiia Lazareva <a.lazareva@thirdpin.ru>
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+SYSTICK implementation, public interface
+*/
+
+#include "systick.hpp"
+
+#ifndef CM3CPP_CUSTOM_SYSTICK
+static volatile uint32_t counter;
+
+void sys_tick_handler(void)
+{
+    counter++;
+}
+#endif
+
+void delay_nop(uint32_t count)
+{
+    while (count--) {
+        __asm("nop");
+    }
+}
+
+namespace cm3cpp {
+
+namespace systick {
+
+#ifndef CM3CPP_CUSTOM_SYSTICK
+void delay_systick(uint32_t ms)
+{
+    uint32_t time = get_counter();
+    while ((get_counter() - time) < ms) {
+        __asm("nop");
+    }
+}
+#endif  // CM3CPP_CUSTOM_SYSTICK
+
+void init(uint32_t system_core_freq, uint32_t clock_div)
+{
+#ifndef CM3CPP_CUSTOM_SYSTICK
+    counter = 0;
+#endif
+    systick_set_reload(system_core_freq / clock_div);
+    systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);
+    systick_counter_enable();
+    systick_interrupt_enable();
+}
+
+void deinit()
+{
+    systick_interrupt_disable();
+    systick_counter_disable();
+}
+
+#ifndef CM3CPP_CUSTOM_SYSTICK
+uint32_t get_counter()
+{
+    return counter;
+}
+
+Counter::Counter(Mode mode, uint32_t period)
+{
+    init(mode, period);
+}
+
+void Counter::init(Mode mode, uint32_t period)
+{
+    _mode = mode;
+    _saved = get_counter();
+    _period = period;
+
+    switch (_mode) {
+        case CYCLE:
+            _is_active = true;
+            break;
+        case ONE_SHOT:
+            _is_active = false;
+            break;
+    }
+}
+
+bool Counter::timeout()
+{
+    if (_is_active && ((get_counter() - _saved) >= _period)) {
+        switch (_mode) {
+            case CYCLE:
+                _saved = get_counter();
+                return true;
+            case ONE_SHOT:
+                return true;
+        }
+    }
+
+    return false;
+}
+
+bool Counter::start()
+{
+    if (_mode == CYCLE)
+        return false;
+    _saved = get_counter();
+    _is_active = true;
+    return true;
+}
+
+bool Counter::stop()
+{
+    if (_mode == CYCLE)
+        return false;
+    _is_active = false;
+    return true;
+}
+
+}  // namespace systick
+#endif  // CM3CPP_CUSTOM_SYSTICK
+
+}  // namespace cm3cpp