Merge branch 'master' of ssh://git.gag.com/scm/git/fw/altos

[fw/altos] / src / drivers / ao_trng_send.c

diff --git a/src/drivers/ao_trng_send.c b/src/drivers/ao_trng_send.c
new file mode 100644 (file)
index 0000000..bac6035
--- /dev/null
+++ b/src/drivers/ao_trng_send.c
@@ -0,0 +1,65 @@
+/*
+ * 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; version 2 of the License.
+ *
+ * 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_send.h>
+
+static void
+ao_trng_send(void)
+{
+       static uint16_t *buffer[2];
+       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;
+       }
+
+       usb_buf_id = 0;
+
+       ao_crc_reset();
+
+       for (;;) {
+               ao_led_on(AO_LED_TRNG_ACTIVE);
+               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_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;
+
+void
+ao_trng_send_init(void)
+{
+       ao_add_task(&ao_trng_send_task, ao_trng_send, "trng_send");
+}