// 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); }