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

1 files changed, 79 insertions, 0 deletions

diff --git a/src/drivers/ao_trng.c b/src/drivers/ao_trng.c
new file mode 100644
index 00000000..e69cd30b
--- /dev/null
+++ b/src/drivers/ao_trng.c
@@ -0,0 +1,79 @@
+/*
+ * 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.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);
+}