1 files changed, 90 insertions, 0 deletions
diff --git a/cc3200/misc/mpsystick.c b/cc3200/misc/mpsystick.c
new file mode 100644
index 000000000..5eeeae21e
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+++ b/cc3200/misc/mpsystick.c
@@ -0,0 +1,90 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013, 2014 Damien P. George
+ * Copyright (c) 2015 Daniel Campora
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "py/mpconfig.h"
+#include MICROPY_HAL_H
+#include "py/obj.h"
+#include "irq.h"
+#include "mpsystick.h"
+#include "systick.h"
+#include "inc/hw_types.h"
+#include "inc/hw_nvic.h"
+
+#ifdef USE_FREERTOS
+#include "FreeRTOS.h"
+#include "task.h"
+#endif
+
+
+bool sys_tick_has_passed(uint32_t start_tick, uint32_t delay_ms) {
+    return HAL_GetTick() - start_tick >= delay_ms;
+}
+
+// waits until at least delay_ms milliseconds have passed from the sampling of
+// startTick. Handles overflow properly. Assumes stc was taken from
+// HAL_GetTick() some time before calling this function.
+void sys_tick_wait_at_least(uint32_t start_tick, uint32_t delay_ms) {
+#ifdef USE_FREERTOS
+    vTaskDelay (delay_ms / portTICK_PERIOD_MS);
+#else
+    while (!sys_tick_has_passed(start_tick, delay_ms)) {
+        __WFI(); // enter sleep mode, waiting for interrupt
+    }
+#endif
+}
+
+// The SysTick timer counts down at HAL_FCPU_HZ, so we can use that knowledge
+// to grab a microsecond counter.
+//
+// We assume that HAL_GetTick returns milliseconds.
+uint32_t sys_tick_get_microseconds(void) {
+    mp_uint_t irq_state = disable_irq();
+    uint32_t counter = SysTickValueGet();
+    uint32_t milliseconds = HAL_GetTick();
+    uint32_t status  = (HWREG(NVIC_ST_CTRL));
+    enable_irq(irq_state);
+
+    // It's still possible for the countflag bit to get set if the counter was
+    // reloaded between reading VAL and reading CTRL. With interrupts  disabled
+    // it definitely takes less than 50 HCLK cycles between reading VAL and
+    // reading CTRL, so the test (counter > 50) is to cover the case where VAL
+    // is +ve and very close to zero, and the COUNTFLAG bit is also set.
+    if ((status & NVIC_ST_CTRL_COUNT) && counter > 50) {
+        // This means that the HW reloaded VAL between the time we read VAL and the
+        // time we read CTRL, which implies that there is an interrupt pending
+        // to increment the tick counter.
+        milliseconds++;
+    }
+    uint32_t load = (HWREG(NVIC_ST_RELOAD));
+    counter = load - counter; // Convert from decrementing to incrementing
+
+    // ((load + 1) / 1000) is the number of counts per microsecond.
+    //
+    // counter / ((load + 1) / 1000) scales from the systick clock to microseconds
+    // and is the same thing as (counter * 1000) / (load + 1)
+    return milliseconds * 1000 + (counter * 1000) / (load + 1);
+}