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/*
* Copyright © 2015 Keith Packard <keithp@keithp.com>
*
* 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; 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
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include <ao.h>
#include <ao_adc_fast.h>
#include <ao_crc.h>
#include <ao_trng.h>
static void
ao_trng_fetch(void)
{
static uint16_t *buffer[2];
uint32_t kbytes = 1;
uint32_t count;
int usb_buf_id;
uint16_t i;
uint16_t *buf;
uint16_t t;
uint32_t *rnd = (uint32_t *) ao_adc_ring;
if (!buffer[0]) {
buffer[0] = ao_usb_alloc();
buffer[1] = ao_usb_alloc();
if (!buffer[0])
return;
}
ao_cmd_decimal();
if (ao_cmd_status == ao_cmd_success)
kbytes = ao_cmd_lex_u32;
else
ao_cmd_status = ao_cmd_success;
usb_buf_id = 0;
count = kbytes * (1024/AO_USB_IN_SIZE);
ao_crc_reset();
ao_led_on(AO_LED_TRNG_READ);
while (count--) {
t = ao_adc_get(AO_USB_IN_SIZE) >> 1; /* 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[t]);
t = (t + 1) & ((AO_ADC_RING_SIZE>>1) - 1);
}
ao_adc_ack(AO_USB_IN_SIZE);
ao_led_toggle(AO_LED_TRNG_READ|AO_LED_TRNG_WRITE);
ao_usb_write(buffer[usb_buf_id], AO_USB_IN_SIZE);
ao_led_toggle(AO_LED_TRNG_READ|AO_LED_TRNG_WRITE);
usb_buf_id = 1-usb_buf_id;
}
ao_led_off(AO_LED_TRNG_READ|AO_LED_TRNG_WRITE);
flush();
}
static const struct ao_cmds ao_trng_cmds[] = {
{ ao_trng_fetch, "f <kbytes>\0Fetch a block of numbers" },
{ 0, NULL },
};
void
ao_trng_init(void)
{
ao_cmd_register(ao_trng_cmds);
}
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