diff options
| -rw-r--r-- | stmhal/irq.h | 6 | ||||
| -rw-r--r-- | stmhal/modpyb.c | 5 | ||||
| -rw-r--r-- | stmhal/systick.c | 39 | ||||
| -rw-r--r-- | stmhal/systick.h | 1 |
4 files changed, 40 insertions, 11 deletions
diff --git a/stmhal/irq.h b/stmhal/irq.h index ef595b7446..6689e995dc 100644 --- a/stmhal/irq.h +++ b/stmhal/irq.h @@ -24,10 +24,14 @@ * THE SOFTWARE. */ -// these states correspond to values from enable_irq and disable_irq +// these states correspond to values from query_irq, enable_irq and disable_irq #define IRQ_STATE_DISABLED (0x00000001) #define IRQ_STATE_ENABLED (0x00000000) +static inline mp_uint_t query_irq(void) { + return __get_PRIMASK(); +} + // enable_irq and disable_irq are defined inline in mpconfigport.h MP_DECLARE_CONST_FUN_OBJ(pyb_wfi_obj); diff --git a/stmhal/modpyb.c b/stmhal/modpyb.c index 38c5499b0b..46ce0e0987 100644 --- a/stmhal/modpyb.c +++ b/stmhal/modpyb.c @@ -402,10 +402,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_delay_obj, pyb_delay); STATIC mp_obj_t pyb_udelay(mp_obj_t usec_in) { mp_int_t usec = mp_obj_get_int(usec_in); if (usec > 0) { - uint32_t count = 0; - const uint32_t utime = (168 * usec / 4); - while (++count <= utime) { - } + sys_tick_udelay(usec); } return mp_const_none; } diff --git a/stmhal/systick.c b/stmhal/systick.c index b4dd68ffec..fc462943f8 100644 --- a/stmhal/systick.c +++ b/stmhal/systick.c @@ -36,12 +36,39 @@ // We provide our own version of HAL_Delay that calls __WFI while waiting, in // order to reduce power consumption. void HAL_Delay(uint32_t Delay) { - extern __IO uint32_t uwTick; - uint32_t start = uwTick; - // Wraparound of tick is taken care of by 2's complement arithmetic. - while (uwTick - start < Delay) { - // Enter sleep mode, waiting for (at least) the SysTick interrupt. - __WFI(); + if (query_irq() == IRQ_STATE_ENABLED) { + // IRQs enabled, so can use systick counter to do the delay + extern __IO uint32_t uwTick; + uint32_t start = uwTick; + // Wraparound of tick is taken care of by 2's complement arithmetic. + while (uwTick - start < Delay) { + // Enter sleep mode, waiting for (at least) the SysTick interrupt. + __WFI(); + } + } else { + // IRQs disabled, so need to use a busy loop for the delay. + // To prevent possible overflow of the counter we use a double loop. + const uint32_t count_1ms = HAL_RCC_GetSysClockFreq() / 4000; + for (int i = 0; i < Delay; i++) { + for (uint32_t count = 0; ++count <= count_1ms;) { + } + } + } +} + +// delay for given number of microseconds +void sys_tick_udelay(uint32_t usec) { + if (query_irq() == IRQ_STATE_ENABLED) { + // IRQs enabled, so can use systick counter to do the delay + uint32_t start = sys_tick_get_microseconds(); + while (sys_tick_get_microseconds() - start < usec) { + } + } else { + // IRQs disabled, so need to use a busy loop for the delay + // sys freq is always a multiple of 2MHz, so division here won't lose precision + const uint32_t ucount = HAL_RCC_GetSysClockFreq() / 2000000 * usec / 2; + for (uint32_t count = 0; ++count <= ucount;) { + } } } diff --git a/stmhal/systick.h b/stmhal/systick.h index 98045d16c4..5a4dfb3ed2 100644 --- a/stmhal/systick.h +++ b/stmhal/systick.h @@ -24,6 +24,7 @@ * THE SOFTWARE. */ +void sys_tick_udelay(uint32_t usec); void sys_tick_wait_at_least(uint32_t stc, uint32_t delay_ms); bool sys_tick_has_passed(uint32_t stc, uint32_t delay_ms); uint32_t sys_tick_get_microseconds(void); |