+#include <ao_exti.h>
+#include <ao_power.h>
+
+static uint8_t trng_running;
+
+static void
+ao_trng_send_raw(uint16_t *buf)
+{
+ uint16_t i;
+ uint16_t t;
+ uint16_t *rnd = (uint16_t *) ao_adc_ring;
+
+ t = ao_adc_get(AO_USB_IN_SIZE>>1); /* one 16-bit value per two output bytes */
+ for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++) {
+ *buf++ = rnd[t];
+ t = (t + 1) & (AO_ADC_RING_SIZE - 1);
+ }
+}
+
+static void
+ao_trng_send_cooked(uint16_t *buf)
+{
+ uint16_t i;
+ uint16_t t;
+ uint32_t *rnd = (uint32_t *) ao_adc_ring;
+
+ t = ao_adc_get(AO_USB_IN_SIZE) >> 1; /* one 16-bit value per output byte */
+ for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++) {
+ *buf++ = ao_crc_in_32_out_16(rnd[t]);
+ t = (t + 1) & ((AO_ADC_RING_SIZE>>1) - 1);
+ }
+}
+
+static inline int
+ao_send_raw(void)
+{
+ return !ao_gpio_get(AO_RAW_PORT, AO_RAW_BIT, AO_RAW_PIN);
+}