1 files changed, 159 insertions, 0 deletions
diff --git a/bsps/arm/shared/clock/clock-armv7m.c b/bsps/arm/shared/clock/clock-armv7m.c
new file mode 100644
index 0000000000..39cd4efdc7
--- /dev/null
+++ b/bsps/arm/shared/clock/clock-armv7m.c
@@ -0,0 +1,159 @@
+/*
+ * Copyright (c) 2011-2012 Sebastian Huber.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Obere Lagerstr. 30
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#include <rtems.h>
+#include <rtems/timecounter.h>
+#include <rtems/score/armv7m.h>
+
+#include <bsp.h>
+
+#ifdef ARM_MULTILIB_ARCH_V7M
+
+/* This is defined in dev/clock/clockimpl.h */
+static void Clock_isr(void *arg);
+
+typedef struct {
+  rtems_timecounter_simple base;
+  void (*tick)(void);
+  bool countflag;
+} ARMV7M_Timecounter;
+
+static ARMV7M_Timecounter _ARMV7M_TC;
+
+static uint32_t _ARMV7M_TC_systick_get(rtems_timecounter_simple *tc)
+{
+  volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
+
+  return systick->cvr;
+}
+
+static bool _ARMV7M_TC_systick_is_pending(rtems_timecounter_simple *base)
+{
+  ARMV7M_Timecounter *tc = (ARMV7M_Timecounter *) base;
+  rtems_interrupt_level level;
+  bool countflag;
+
+  rtems_interrupt_disable(level);
+
+  countflag = tc->countflag;
+  if (!countflag) {
+    volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
+
+    countflag = ((systick->csr & ARMV7M_SYSTICK_CSR_COUNTFLAG) != 0);
+    tc->countflag = countflag;
+  }
+
+  rtems_interrupt_enable(level);
+
+  return countflag;
+}
+
+static uint32_t _ARMV7M_TC_systick_get_timecount(struct timecounter *tc)
+{
+  return rtems_timecounter_simple_downcounter_get(
+    tc,
+    _ARMV7M_TC_systick_get,
+    _ARMV7M_TC_systick_is_pending
+  );
+}
+
+static void _ARMV7M_TC_systick_at_tick(rtems_timecounter_simple *base)
+{
+  ARMV7M_Timecounter *tc = (ARMV7M_Timecounter *) base;
+  volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
+
+  tc->countflag = false;
+
+  /* Clear COUNTFLAG */
+  systick->csr;
+}
+
+static void _ARMV7M_TC_systick_tick(void)
+{
+  rtems_timecounter_simple_downcounter_tick(
+    &_ARMV7M_TC.base,
+    _ARMV7M_TC_systick_get,
+    _ARMV7M_TC_systick_at_tick
+  );
+}
+
+static void _ARMV7M_TC_tick(void)
+{
+  (*_ARMV7M_TC.tick)();
+}
+
+static void _ARMV7M_Systick_handler(void)
+{
+  _ARMV7M_Interrupt_service_enter();
+  Clock_isr(NULL);
+  _ARMV7M_Interrupt_service_leave();
+}
+
+static void _ARMV7M_Systick_handler_install(void)
+{
+  _ARMV7M_Set_exception_priority_and_handler(
+    ARMV7M_VECTOR_SYSTICK,
+    BSP_ARMV7M_SYSTICK_PRIORITY,
+    _ARMV7M_Systick_handler
+  );
+}
+
+static void _ARMV7M_Systick_initialize(void)
+{
+  volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
+  #ifdef BSP_ARMV7M_SYSTICK_FREQUENCY
+    uint64_t freq = BSP_ARMV7M_SYSTICK_FREQUENCY;
+  #else
+    uint64_t freq = ARMV7M_SYSTICK_CALIB_TENMS_GET(systick->calib) * 100ULL;
+  #endif
+  uint64_t us_per_tick = rtems_configuration_get_microseconds_per_tick();
+  uint64_t interval = (freq * us_per_tick) / 1000000ULL;
+
+  systick->rvr = (uint32_t) interval;
+  systick->cvr = 0;
+  systick->csr = ARMV7M_SYSTICK_CSR_ENABLE
+    | ARMV7M_SYSTICK_CSR_TICKINT
+    | ARMV7M_SYSTICK_CSR_CLKSOURCE;
+
+  _ARMV7M_TC.tick = _ARMV7M_TC_systick_tick;
+  rtems_timecounter_simple_install(
+    &_ARMV7M_TC.base,
+    freq,
+    interval,
+    _ARMV7M_TC_systick_get_timecount
+  );
+}
+
+static void _ARMV7M_Systick_cleanup(void)
+{
+  volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
+
+  systick->csr = 0;
+}
+
+#define Clock_driver_timecounter_tick() _ARMV7M_TC_tick()
+
+#define Clock_driver_support_initialize_hardware() \
+  _ARMV7M_Systick_initialize()
+
+#define Clock_driver_support_install_isr(isr) \
+  _ARMV7M_Systick_handler_install()
+
+#define Clock_driver_support_shutdown_hardware() \
+  _ARMV7M_Systick_cleanup()
+
+/* Include shared source clock driver code */
+#include "../../../shared/dev/clock/clockimpl.h"
+
+#endif /* ARM_MULTILIB_ARCH_V7M */