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1// SPDX-License-Identifier: GPL-2.02/*3 * sl3516-ce-rng.c - hardware cryptographic offloader for SL3516 SoC.4 *5 * Copyright (C) 2021 Corentin Labbe <clabbe@baylibre.com>6 *7 * This file handle the RNG found in the SL3516 crypto engine8 */9#include "sl3516-ce.h"10#include <linux/pm_runtime.h>11#include <linux/hw_random.h>12 13static int sl3516_ce_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)14{15 struct sl3516_ce_dev *ce;16 u32 *data = buf;17 size_t read = 0;18 int err;19 20 ce = container_of(rng, struct sl3516_ce_dev, trng);21 22#ifdef CONFIG_CRYPTO_DEV_SL3516_DEBUG23 ce->hwrng_stat_req++;24 ce->hwrng_stat_bytes += max;25#endif26 27 err = pm_runtime_get_sync(ce->dev);28 if (err < 0) {29 pm_runtime_put_noidle(ce->dev);30 return err;31 }32 33 while (read < max) {34 *data = readl(ce->base + IPSEC_RAND_NUM_REG);35 data++;36 read += 4;37 }38 39 pm_runtime_put(ce->dev);40 41 return read;42}43 44int sl3516_ce_rng_register(struct sl3516_ce_dev *ce)45{46 int ret;47 48 ce->trng.name = "SL3516 Crypto Engine RNG";49 ce->trng.read = sl3516_ce_rng_read;50 ce->trng.quality = 700;51 52 ret = hwrng_register(&ce->trng);53 if (ret)54 dev_err(ce->dev, "Fail to register the RNG\n");55 return ret;56}57 58void sl3516_ce_rng_unregister(struct sl3516_ce_dev *ce)59{60 hwrng_unregister(&ce->trng);61}62