*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
#include <ao_crc.h>
#include <ao_trng_send.h>
#include <ao_exti.h>
+#include <ao_power.h>
+
+static struct ao_task ao_trng_send_task;
+static uint8_t trng_running;
+static AO_TICK_TYPE trng_power_time;
+
+#define TRNG_ENABLE_DELAY AO_MS_TO_TICKS(100)
+
+static uint8_t random_mutex;
+
+#if AO_USB_HAS_IN2
+
+static struct ao_task ao_trng_send_raw_task;
static void
-ao_trng_send_raw(uint16_t *buf)
+ao_trng_get_raw(uint16_t *buf)
{
uint16_t i;
uint16_t t;
- uint16_t *rnd = (uint16_t *) ao_adc_ring;
+ uint16_t v;
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];
+ v = ao_adc_ring[t];
+ *buf++ = v;
t = (t + 1) & (AO_ADC_RING_SIZE - 1);
}
+ ao_adc_ack(AO_USB_IN_SIZE>>1);
}
static void
-ao_trng_send_cooked(uint16_t *buf)
+ao_trng_send_raw(void)
+{
+ static uint16_t *buffer[2];
+ int usb_buf_id;
+
+ if (!buffer[0]) {
+ buffer[0] = ao_usb_alloc();
+ buffer[1] = ao_usb_alloc();
+ if (!buffer[0])
+ ao_exit();
+ }
+
+ usb_buf_id = 0;
+
+ for (;;) {
+ ao_mutex_get(&random_mutex);
+ if (!trng_running) {
+ AO_TICK_TYPE delay;
+
+ delay = trng_power_time + TRNG_ENABLE_DELAY - ao_time();
+ if (delay > TRNG_ENABLE_DELAY)
+ delay = TRNG_ENABLE_DELAY;
+
+ /* Delay long enough for the HV power supply
+ * to stabilize so that the first bits we read
+ * aren't of poor quality
+ */
+ ao_delay(delay);
+ trng_running = TRUE;
+ }
+#ifdef AO_LED_TRNG_RAW
+ ao_led_on(AO_LED_TRNG_RAW);
+#endif
+ ao_trng_get_raw(buffer[usb_buf_id]);
+#ifdef AO_LED_TRNG_RAW
+ ao_led_off(AO_LED_TRNG_RAW);
+#endif
+ ao_mutex_put(&random_mutex);
+ ao_usb_write2(buffer[usb_buf_id], AO_USB_IN_SIZE);
+ usb_buf_id = 1-usb_buf_id;
+ }
+}
+
+#endif
+
+static uint32_t previous[AO_USB_IN_SIZE / sizeof (uint16_t)];
+
+static int
+ao_trng_get_cooked(uint16_t *buf)
{
uint16_t i;
uint16_t t;
uint32_t *rnd = (uint32_t *) ao_adc_ring;
+ uint8_t mismatch = 0;
- t = ao_adc_get(AO_USB_IN_SIZE) >> 1; /* one 16-bit value per output byte */
+ 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);
+ uint32_t v;
+
+ /* Fetch two values in one operation */
+ v = rnd[t];
+ if (v != previous[i]) {
+ mismatch = 1;
+ previous[i] = v;
+ }
+ t = (t + 1) & ((AO_ADC_RING_SIZE >> 1) - 1);
+
+ *buf++ = ao_crc_in_32_out_16(v);
}
+ ao_adc_ack(AO_USB_IN_SIZE);
+ return mismatch;
}
-static inline int
-ao_send_raw(void)
-{
- return !ao_gpio_get(AO_RAW_PORT, AO_RAW_BIT, AO_RAW_PIN);
-}
+#define AO_TRNG_START_WAIT 1024
+#define AO_TRNG_START_CHECK 32
static void
ao_trng_send(void)
{
static uint16_t *buffer[2];
int usb_buf_id;
+ int good_bits;
+ int failed;
+ int s;
if (!buffer[0]) {
buffer[0] = ao_usb_alloc();
buffer[1] = ao_usb_alloc();
if (!buffer[0])
- return;
+ ao_exit();
}
usb_buf_id = 0;
+#ifdef AO_TRNG_ENABLE_PORT
+ ao_gpio_set(AO_TRNG_ENABLE_PORT, AO_TRNG_ENABLE_BIT, AO_TRNG_ENABLE_PIN, 1);
+#endif
+ trng_power_time = ao_time();
+
ao_crc_reset();
+ ao_delay(TRNG_ENABLE_DELAY);
+
+ for (s = 0; s < AO_TRNG_START_WAIT; s++) {
+ if (ao_trng_get_cooked(buffer[0]))
+ break;
+ ao_delay(AO_MS_TO_TICKS(10));
+ }
+
+ /* Validate the hardware before enabling USB */
+ failed = 0;
+ for (s = 0; s < AO_TRNG_START_CHECK; s++) {
+ if (!ao_trng_get_cooked(buffer[0])) {
+ failed++;
+ ao_delay(AO_MS_TO_TICKS(10));
+ }
+ }
+ if (failed > AO_TRNG_START_CHECK / 4)
+ ao_panic(AO_PANIC_DMA);
+
+#if AO_USB_HAS_IN2
+ ao_add_task(&ao_trng_send_raw_task, ao_trng_send_raw, "trng_send_raw");
+#endif
+
+#ifdef AO_USB_START_DISABLED
+ ao_usb_enable();
+#endif
+
for (;;) {
- 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);
+ ao_mutex_get(&random_mutex);
+ if (!trng_running) {
+ AO_TICK_TYPE delay;
+
+ delay = trng_power_time + TRNG_ENABLE_DELAY - ao_time();
+ if (delay > TRNG_ENABLE_DELAY)
+ delay = TRNG_ENABLE_DELAY;
+
+ /* Delay long enough for the HV power supply
+ * to stabilize so that the first bits we read
+ * aren't of poor quality
+ */
+ ao_delay(delay);
+ trng_running = TRUE;
+ }
+#ifdef AO_LED_TRNG_COOKED
+ ao_led_on(AO_LED_TRNG_COOKED);
+#endif
+ good_bits = ao_trng_get_cooked(buffer[usb_buf_id]);
+#ifdef AO_LED_TRNG_COOKED
+ ao_led_off(AO_LED_TRNG_COOKED);
+#endif
+ ao_mutex_put(&random_mutex);
+ if (good_bits) {
+ ao_usb_write(buffer[usb_buf_id], AO_USB_IN_SIZE);
+ usb_buf_id = 1-usb_buf_id;
+ failed = 0;
} else {
- ao_led_on(AO_LED_TRNG_COOKED);
- ao_trng_send_cooked(buffer[usb_buf_id]);
- ao_led_off(AO_LED_TRNG_COOKED);
+ failed++;
+ ao_delay(AO_MS_TO_TICKS(10));
+ if (failed > 10) {
+ ao_usb_disable();
+ ao_panic(AO_PANIC_DMA);
+ }
}
- ao_adc_ack(AO_USB_IN_SIZE);
- 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
+ trng_power_time = ao_time();
+}
+
+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, 0);
+ 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");
}
projects / fw / altos / blobdiff