dm: rng: Add random number generator(rng) uclass
Add a uclass for reading a random number seed from a random number
generator device.
Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/include/rng.h b/include/rng.h
new file mode 100644
index 0000000..d2c0f9a
--- /dev/null
+++ b/include/rng.h
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2019, Linaro Limited
+ */
+
+#if !defined _RNG_H_
+#define _RNG_H_
+
+struct udevice;
+
+/**
+ * dm_rng_read() - read a random number seed from the rng device
+ * @buffer: input buffer to put the read random seed into
+ * @size: number of bytes of random seed read
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
+
+/* struct dm_rng_ops - Operations for the hwrng uclass */
+struct dm_rng_ops {
+ /**
+ * @read() - read a random number seed
+ *
+ * @data: input buffer to read the random seed
+ * @max: total number of bytes to read
+ *
+ * Return: 0 if OK, -ve on error
+ */
+ int (*read)(struct udevice *dev, void *data, size_t max);
+};
+
+#endif /* _RNG_H_ */