2 * Copyright © 2015 Keith Packard <keithp@keithp.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
19 #include <ao_adc_fast.h>
21 #include <ao_trng_send.h>
25 ao_trng_send_raw(uint16_t *buf)
29 uint16_t *rnd = (uint16_t *) ao_adc_ring;
31 t = ao_adc_get(AO_USB_IN_SIZE>>1); /* one 16-bit value per two output bytes */
32 for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++) {
34 t = (t + 1) & (AO_ADC_RING_SIZE - 1);
39 ao_trng_send_cooked(uint16_t *buf)
43 uint32_t *rnd = (uint32_t *) ao_adc_ring;
45 t = ao_adc_get(AO_USB_IN_SIZE) >> 1; /* one 16-bit value per output byte */
46 for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++) {
47 *buf++ = ao_crc_in_32_out_16(rnd[t]);
48 t = (t + 1) & ((AO_ADC_RING_SIZE>>1) - 1);
55 return !ao_gpio_get(AO_RAW_PORT, AO_RAW_BIT, AO_RAW_PIN);
61 static uint16_t *buffer[2];
65 buffer[0] = ao_usb_alloc();
66 buffer[1] = ao_usb_alloc();
75 /* Delay long enough for the HV power supply to stabilize so that the
76 * first bits we read aren't of poor quality
78 ao_delay(AO_MS_TO_TICKS(250));
82 ao_led_on(AO_LED_TRNG_RAW);
83 ao_trng_send_raw(buffer[usb_buf_id]);
84 ao_led_off(AO_LED_TRNG_RAW);
86 ao_led_on(AO_LED_TRNG_COOKED);
87 ao_trng_send_cooked(buffer[usb_buf_id]);
88 ao_led_off(AO_LED_TRNG_COOKED);
90 ao_adc_ack(AO_USB_IN_SIZE);
91 ao_usb_write(buffer[usb_buf_id], AO_USB_IN_SIZE);
92 usb_buf_id = 1-usb_buf_id;
96 static struct ao_task ao_trng_send_task;
99 ao_trng_send_init(void)
101 ao_enable_input(AO_RAW_PORT, AO_RAW_BIT, AO_EXTI_MODE_PULL_UP);
102 ao_add_task(&ao_trng_send_task, ao_trng_send, "trng_send");