static int entropy_nrf5_get_entropy_isr(struct device *dev, u8_t *buf, u16_t len,
u32_t flags)
{
u16_t cnt = len;
/* Check if this API is called on correct driver instance. */
__ASSERT_NO_MSG(&entropy_nrf5_data == DEV_DATA(dev));
if (likely((flags & ENTROPY_BUSYWAIT) == 0)) {
return rng_pool_get((struct rng_pool *)(entropy_nrf5_data.isr),
buf, len);
}
if (len) {
unsigned int key;
int irq_enabled;
key = irq_lock();
irq_enabled = irq_is_enabled(RNG_IRQn);
irq_disable(RNG_IRQn);
irq_unlock(key);
nrf_rng_event_clear(NRF_RNG_EVENT_VALRDY);
nrf_rng_task_trigger(NRF_RNG_TASK_START);
do {
int byte;
while (!nrf_rng_event_get(NRF_RNG_EVENT_VALRDY)) {
__WFE();
__SEV();
__WFE();
}
byte = random_byte_get();
NVIC_ClearPendingIRQ(RNG_IRQn);
if (byte < 0) {
continue;
}
buf[--len] = byte;
} while (len);
if (irq_enabled) {
irq_enable(RNG_IRQn);
}
}
return cnt;
}
void RNG_IRQHandler(void)
{
if (nrf_rng_event_get(NRF_RNG_EVENT_VALRDY) &&
nrf_rng_int_get(NRF_RNG_INT_VALRDY_MASK))
{
nrf_rng_event_clear(NRF_RNG_EVENT_VALRDY);
uint32_t nrf_error = app_fifo_put(&m_rng_cb.rand_pool, nrf_rng_random_value_get());
if ((FIFO_LENGTH(m_rng_cb.rand_pool) > m_rng_cb.rand_pool.buf_size_mask) || (nrf_error == NRF_ERROR_NO_MEM))
{
rng_stop();
}
}
}
void RNG_IRQHandler(void)
{
if (nrf_rng_event_get(NRF_RNG_EVENT_VALRDY) && nrf_rng_int_get(NRF_RNG_INT_VALRDY_MASK))
{
nrf_rng_event_clear(NRF_RNG_EVENT_VALRDY);
bufferPut(nrf_rng_random_value_get());
if (bufferIsFull())
{
generatorStop();
}
}
}
static inline u8_t entropy_nrf5_get_u8(void)
{
while (!nrf_rng_event_get(NRF_RNG_EVENT_VALRDY)) {
__WFE();
__SEV();
__WFE();
}
nrf_rng_event_clear(NRF_RNG_EVENT_VALRDY);
/* Clear the Pending status of the RNG interrupt so that it could
* wake up the core when the VALRDY event occurs again. */
NVIC_ClearPendingIRQ(RNG_IRQn);
return nrf_rng_random_value_get();
}
static int random_byte_get(void)
{
int retval = -EAGAIN;
unsigned int key;
key = irq_lock();
if (nrf_rng_event_get(NRF_RNG_EVENT_VALRDY)) {
retval = nrf_rng_random_value_get();
nrf_rng_event_clear(NRF_RNG_EVENT_VALRDY);
}
irq_unlock(key);
return retval;
}