#include <ao_adc_fast.h>
#include <ao_crc.h>
#include <ao_trng_send.h>
+#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);
+}
static void
ao_trng_send(void)
{
static uint16_t *buffer[2];
- int usb_buf_id;
- uint16_t i;
- uint16_t *buf;
- uint32_t *rnd;
+ int usb_buf_id;
if (!buffer[0]) {
buffer[0] = ao_usb_alloc();
ao_crc_reset();
for (;;) {
- ao_led_on(AO_LED_TRNG_ACTIVE);
- rnd = (uint32_t *) ao_adc_get(AO_USB_IN_SIZE); /* one 16-bit value per output byte */
- buf = buffer[usb_buf_id];
- for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++)
- *buf++ = ao_crc_in_32_out_16(*rnd++);
+ if (!trng_running) {
+ /* Delay long enough for the HV power supply
+ * to stabilize so that the first bits we read
+ * aren't of poor quality
+ */
+ ao_delay(AO_MS_TO_TICKS(10));
+ trng_running = TRUE;
+ }
+ if (ao_send_raw()) {
+ ao_led_on(AO_LED_TRNG_RAW);
+ ao_trng_send_raw(buffer[usb_buf_id]);
+ ao_led_off(AO_LED_TRNG_RAW);
+ } else {
+ ao_led_on(AO_LED_TRNG_COOKED);
+ ao_trng_send_cooked(buffer[usb_buf_id]);
+ ao_led_off(AO_LED_TRNG_COOKED);
+ }
ao_adc_ack(AO_USB_IN_SIZE);
- ao_led_off(AO_LED_TRNG_ACTIVE);
ao_usb_write(buffer[usb_buf_id], AO_USB_IN_SIZE);
usb_buf_id = 1-usb_buf_id;
}
static struct ao_task ao_trng_send_task;
+#if AO_POWER_MANAGEMENT
+
+static void ao_trng_suspend(void *arg)
+{
+ (void) arg;
+#ifdef AO_TRNG_ENABLE_PORT
+ ao_gpio_set(AO_TRNG_ENABLE_PORT, AO_TRNG_ENABLE_BIT, AO_TRNG_ENABLE_PIN, 0);
+#endif
+ trng_running = FALSE;
+}
+
+static void ao_trng_resume(void *arg)
+{
+ (void) arg;
+#ifdef AO_TRNG_ENABLE_PORT
+ ao_gpio_set(AO_TRNG_ENABLE_PORT, AO_TRNG_ENABLE_BIT, AO_TRNG_ENABLE_PIN, 1);
+#endif
+}
+
+static struct ao_power ao_trng_power = {
+ .suspend = ao_trng_suspend,
+ .resume = ao_trng_resume
+};
+
+#endif
+
void
ao_trng_send_init(void)
{
+#ifdef AO_TRNG_ENABLE_PORT
+ ao_enable_output(AO_TRNG_ENABLE_PORT, AO_TRNG_ENABLE_BIT, AO_TRNG_ENABLE_PIN, 1);
+ ao_power_register(&ao_trng_power);
+#endif
+ ao_enable_input(AO_RAW_PORT, AO_RAW_BIT, AO_EXTI_MODE_PULL_UP);
ao_add_task(&ao_trng_send_task, ao_trng_send, "trng_send");
}