src/crc.c: Add missing file.

src/crc.c

@@ -0,0 +1,43 @@
+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2015 Aurelien Jacobs <aurel@gnuage.org>
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdint.h>
+#include <libsigrok/libsigrok.h>
+#include "libsigrok-internal.h"
+
+SR_PRIV uint16_t sr_crc16(uint16_t crc, const uint8_t *buffer, int len)
+{
+	int i;
+
+	if (!buffer || len < 0)
+		return crc;
+
+	while (len--) {
+		crc ^= *buffer++;
+		for (i = 0; i < 8; i++) {
+			int carry = crc & 1;
+			crc >>= 1;
+			if (carry)
+				crc ^= 0xA001;
+		}
+	}
+
+	return crc;
+}