1 files changed, 53 insertions, 0 deletions
diff --git a/plat/qti/common/src/qti_rng.c b/plat/qti/common/src/qti_rng.c
new file mode 100644
index 0000000..f63f3b8
--- /dev/null
+++ b/plat/qti/common/src/qti_rng.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2020, The Linux Foundation. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#include <stddef.h>
+
+#include <lib/mmio.h>
+
+#include <qti_rng.h>
+#include <qti_rng_io.h>
+
+int qti_rng_get_data(uint8_t *out, uint32_t out_len)
+{
+	uint32_t tmp_rndm = 0;
+	uint32_t bytes_left = out_len;
+	int i = 0;
+
+	if (NULL == out || 0 == out_len) {
+		return -1;
+	}
+
+	/*
+	 * RNG HW initialized at previous boot image.
+	 * RNG clocks are expected to be ON.
+	 */
+
+	do {
+		/* There is no data to read */
+		if ((mmio_read_32(SEC_PRNG_STATUS) &
+		     SEC_PRNG_STATUS_DATA_AVAIL_BMSK) == 0) {
+			continue;
+		}
+
+		while ((tmp_rndm = mmio_read_32(SEC_PRNG_DATA_OUT)) == 0) {
+			;
+		}
+
+		for (i = 0; i < 4; i++) {
+			*out = (uint8_t) (tmp_rndm >> (8 * i));
+
+			out++;
+			bytes_left--;
+
+			if (bytes_left == 0) {
+				break;
+			}
+		}
+
+	} while (bytes_left != 0);
+
+	return 0;
+}