diff options
Diffstat (limited to 'c/src/lib/libbsp/arm/shared/armv7m/startup/armv7m-cpucounter.c')
-rw-r--r-- | c/src/lib/libbsp/arm/shared/armv7m/startup/armv7m-cpucounter.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/arm/shared/armv7m/startup/armv7m-cpucounter.c b/c/src/lib/libbsp/arm/shared/armv7m/startup/armv7m-cpucounter.c new file mode 100644 index 0000000000..16e971f85a --- /dev/null +++ b/c/src/lib/libbsp/arm/shared/armv7m/startup/armv7m-cpucounter.c @@ -0,0 +1,55 @@ +/* + * Copyright (c) 2016 embedded brains GmbH. All rights reserved. + * + * embedded brains GmbH + * Dornierstr. 4 + * 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/score/armv7m.h> +#include <rtems/counter.h> +#include <rtems/sysinit.h> + +#include <bsp.h> +#include <bsp/fatal.h> + +CPU_Counter_ticks _CPU_Counter_read(void) +{ + volatile ARMV7M_DWT *dwt = _ARMV7M_DWT; + + return dwt->cyccnt; +} + +static void armv7m_cpu_counter_initialize(void) +{ + volatile ARMV7M_DWT *dwt = _ARMV7M_DWT; + uint32_t dwt_ctrl; + + dwt_ctrl = dwt->ctrl; + + if ((dwt_ctrl & ARMV7M_DWT_CTRL_NOCYCCNT) == 0) { + #ifdef BSP_ARMV7M_SYSTICK_FREQUENCY + uint64_t freq = BSP_ARMV7M_SYSTICK_FREQUENCY; + #else + volatile ARMV7M_Systick *systick = _ARMV7M_Systick; + uint64_t freq = ARMV7M_SYSTICK_CALIB_TENMS_GET(systick->calib) * 100ULL; + #endif + + dwt->ctrl = dwt_ctrl | ARMV7M_DWT_CTRL_CYCCNTENA; + rtems_counter_initialize_converter(freq); + } else { + bsp_fatal(BSP_ARM_ARMV7M_CPU_COUNTER_INIT); + } +} + +RTEMS_SYSINIT_ITEM( + armv7m_cpu_counter_initialize, + RTEMS_SYSINIT_BSP_START, + RTEMS_SYSINIT_ORDER_FIRST +); |