static int entropy_nrf5_get_entropy(struct device *device, u8_t *buf, u16_t len)
{
/* Mark the peripheral as being used */
atomic_inc(&DEV_DATA(device)->user_count);
/* Disable the shortcut that stops the task after a byte is generated */
nrf_rng_shorts_disable(NRF_RNG_SHORT_VALRDY_STOP_MASK);
/* Start the RNG generator peripheral */
nrf_rng_task_trigger(NRF_RNG_TASK_START);
while (len) {
*buf = entropy_nrf5_get_u8();
buf++;
len--;
}
/* Only stop the RNG generator peripheral if we're the last user */
if (atomic_dec(&DEV_DATA(device)->user_count) == 1) {
/* Disable the peripheral on the next VALRDY event */
nrf_rng_shorts_enable(NRF_RNG_SHORT_VALRDY_STOP_MASK);
if (atomic_get(&DEV_DATA(device)->user_count) != 0) {
/* Race condition: another thread started to use
* the peripheral while we were disabling it.
* Enable the peripheral again
*/
nrf_rng_shorts_disable(NRF_RNG_SHORT_VALRDY_STOP_MASK);
nrf_rng_task_trigger(NRF_RNG_TASK_START);
}
}
return 0;
}
nrfx_err_t nrfx_rng_init(nrfx_rng_config_t const * p_config, nrfx_rng_evt_handler_t handler)
{
NRFX_ASSERT(p_config);
if (m_rng_state != NRFX_DRV_STATE_UNINITIALIZED)
{
return NRFX_ERROR_ALREADY_INITIALIZED;
}
if (handler == NULL)
{
return NRFX_ERROR_INVALID_PARAM;
}
m_rng_hndl = handler;
if (p_config->error_correction)
{
nrf_rng_error_correction_enable();
}
nrf_rng_shorts_disable(NRF_RNG_SHORT_VALRDY_STOP_MASK);
NRFX_IRQ_PRIORITY_SET(RNG_IRQn, p_config->interrupt_priority);
NRFX_IRQ_ENABLE(RNG_IRQn);
m_rng_state = NRFX_DRV_STATE_INITIALIZED;
return NRFX_SUCCESS;
}
ret_code_t nrf_drv_rng_init(nrf_drv_rng_config_t const * p_config)
{
uint32_t result;
if (m_rng_cb.state == NRF_DRV_STATE_UNINITIALIZED)
{
#ifndef SOFTDEVICE_PRESENT
result = app_fifo_init(&m_rng_cb.rand_pool, m_rng_cb.buffer, RNG_CONFIG_POOL_SIZE);
if (p_config == NULL)
{
p_config = &m_default_config;
}
if (result == NRF_SUCCESS)
{
if (p_config->error_correction)
{
nrf_rng_error_correction_enable();
}
nrf_drv_common_irq_enable(RNG_IRQn, p_config->interrupt_priority);
nrf_rng_shorts_disable(NRF_RNG_SHORT_VALRDY_STOP_MASK);
rng_start();
m_rng_cb.state = NRF_DRV_STATE_INITIALIZED;
}
#else
UNUSED_VARIABLE(p_config);
uint8_t softdevice_is_enabled;
result = sd_softdevice_is_enabled(&softdevice_is_enabled);
if (softdevice_is_enabled)
{
m_rng_cb.state = NRF_DRV_STATE_INITIALIZED;
}
else
{
result = NRF_ERROR_SOFTDEVICE_NOT_ENABLED;
}
#endif // SOFTDEVICE_PRESENT
}
else
{
result = NRF_ERROR_INVALID_STATE;
}
return result;
}
void nrf5RandomInit(void)
{
uint32_t seed = 0;
memset(sBuffer, 0, sizeof(sBuffer));
sReadPosition = 0;
sWritePosition = 0;
NVIC_SetPriority(RNG_IRQn, RNG_IRQ_PRIORITY);
NVIC_ClearPendingIRQ(RNG_IRQn);
NVIC_EnableIRQ(RNG_IRQn);
nrf_rng_error_correction_enable();
nrf_rng_shorts_disable(NRF_RNG_SHORT_VALRDY_STOP_MASK);
generatorStart();
// Wait for the first randomized 4 bytes, to randomize software generator seed.
while (!bufferIsUint32Ready())
;
seed = bufferGetUint32();
srand(seed);
}