diff --git a/cpu/nrf5x_common/include/periph_cpu_common.h b/cpu/nrf5x_common/include/periph_cpu_common.h index c6fa1cfc4e37..e2c5a81df70a 100644 --- a/cpu/nrf5x_common/include/periph_cpu_common.h +++ b/cpu/nrf5x_common/include/periph_cpu_common.h @@ -199,6 +199,11 @@ typedef struct { uint8_t irqn; /**< IRQ number of the timer device */ } timer_conf_t; +/** + * @brief The nRF5x periph_timer implements timer_set() + */ +#define PERIPH_TIMER_PROVIDES_SET 1 + #ifndef DOXYGEN /** * @brief Override SPI mode values diff --git a/cpu/nrf5x_common/periph/timer.c b/cpu/nrf5x_common/periph/timer.c index 148f16519b36..ce0644e5198a 100644 --- a/cpu/nrf5x_common/periph/timer.c +++ b/cpu/nrf5x_common/periph/timer.c @@ -117,6 +117,55 @@ int timer_set_absolute(tim_t tim, int chan, unsigned int value) return 0; } +int timer_set(tim_t tim, int chan, unsigned int timeout) +{ + static const uint32_t max_mask[] = { + [TIMER_BITMODE_BITMODE_08Bit] = 0x000000ff, + [TIMER_BITMODE_BITMODE_16Bit] = 0x0000ffff, + [TIMER_BITMODE_BITMODE_24Bit] = 0x00ffffff, + [TIMER_BITMODE_BITMODE_32Bit] = 0xffffffff, + }; + /* see if channel is valid */ + if (chan >= timer_config[tim].channels) { + return -1; + } + + unsigned value = timer_read(tim) + timeout; + + unsigned irq_state = irq_disable(); + ctx[tim].flags |= (1 << chan); + ctx[tim].is_periodic &= ~(1 << chan); + dev(tim)->CC[chan] = value; + + /* clear spurious IRQs */ + dev(tim)->EVENTS_COMPARE[chan] = 0; + (void)dev(tim)->EVENTS_COMPARE[chan]; + + /* enable IRQ */ + dev(tim)->INTENSET = (TIMER_INTENSET_COMPARE0_Msk << chan); + + unsigned expires = value - timer_read(tim); + expires &= max_mask[timer_config[tim].bitmode]; + if (expires > timeout) { + /* timer already expired, check if IRQ flag is set */ + if (!dev(tim)->EVENTS_COMPARE[chan]) { + /* timer has expired but IRQ flag is not set. The only way to not + * wait *a full period* is now to set a new target to the next tick. + * (Setting it to the current timer value will not trigger the IRQ + * flag.) We briefly stop the timer to avoid a race, losing one + * timer tick in accuracy. But that is better than a timer firing + * a whole period too late */ + dev(tim)->TASKS_STOP = 1; + dev(tim)->CC[chan] = timer_read(tim) + 1; + dev(tim)->TASKS_START = 1; + } + } + + irq_restore(irq_state); + + return 0; +} + int timer_set_periodic(tim_t tim, int chan, unsigned int value, uint8_t flags) { /* see if channel is valid */