1 files changed, 61 insertions, 0 deletions
diff --git a/drivers/crypto/gemini/sl3516-ce-rng.c b/drivers/crypto/gemini/sl3516-ce-rng.c
new file mode 100644
index 000000000..76931ec1c
--- /dev/null
+++ b/drivers/crypto/gemini/sl3516-ce-rng.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sl3516-ce-rng.c - hardware cryptographic offloader for SL3516 SoC.
+ *
+ * Copyright (C) 2021 Corentin Labbe <clabbe@baylibre.com>
+ *
+ * This file handle the RNG found in the SL3516 crypto engine
+ */
+#include "sl3516-ce.h"
+#include <linux/pm_runtime.h>
+#include <linux/hw_random.h>
+
+static int sl3516_ce_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+	struct sl3516_ce_dev *ce;
+	u32 *data = buf;
+	size_t read = 0;
+	int err;
+
+	ce = container_of(rng, struct sl3516_ce_dev, trng);
+
+#ifdef CONFIG_CRYPTO_DEV_SL3516_DEBUG
+	ce->hwrng_stat_req++;
+	ce->hwrng_stat_bytes += max;
+#endif
+
+	err = pm_runtime_get_sync(ce->dev);
+	if (err < 0) {
+		pm_runtime_put_noidle(ce->dev);
+		return err;
+	}
+
+	while (read < max) {
+		*data = readl(ce->base + IPSEC_RAND_NUM_REG);
+		data++;
+		read += 4;
+	}
+
+	pm_runtime_put(ce->dev);
+
+	return read;
+}
+
+int sl3516_ce_rng_register(struct sl3516_ce_dev *ce)
+{
+	int ret;
+
+	ce->trng.name = "SL3516 Crypto Engine RNG";
+	ce->trng.read = sl3516_ce_rng_read;
+	ce->trng.quality = 700;
+
+	ret = hwrng_register(&ce->trng);
+	if (ret)
+		dev_err(ce->dev, "Fail to register the RNG\n");
+	return ret;
+}
+
+void sl3516_ce_rng_unregister(struct sl3516_ce_dev *ce)
+{
+	hwrng_unregister(&ce->trng);
+}