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>
26 static uint16_t *buffer[2];
31 uint32_t *rnd = (uint32_t *) ao_adc_ring;
34 buffer[0] = ao_usb_alloc();
35 buffer[1] = ao_usb_alloc();
45 ao_led_on(AO_LED_TRNG_ACTIVE);
46 t = ao_adc_get(AO_USB_IN_SIZE) >> 1; /* one 16-bit value per output byte */
47 buf = buffer[usb_buf_id];
48 for (i = 0; i < AO_USB_IN_SIZE / sizeof (uint16_t); i++) {
49 *buf++ = ao_crc_in_32_out_16(rnd[t]);
50 t = (t + 1) & ((AO_ADC_RING_SIZE>>1) - 1);
52 ao_adc_ack(AO_USB_IN_SIZE);
53 ao_led_off(AO_LED_TRNG_ACTIVE);
54 ao_usb_write(buffer[usb_buf_id], AO_USB_IN_SIZE);
55 usb_buf_id = 1-usb_buf_id;
59 static struct ao_task ao_trng_send_task;
62 ao_trng_send_init(void)
64 ao_add_task(&ao_trng_send_task, ao_trng_send, "trng_send");