crypto: sl3516 - Add sl3516 crypto engine

The cortina/gemini SL3516 SoC has a crypto IP name either (crypto
engine/crypto acceleration engine in the datasheet).
It support many algorithms like [AES|DES|3DES][ECB|CBC], SHA1, MD5 and
some HMAC.

This patch adds the core files and support for ecb(aes) and the RNG.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/Kconfig

@@ -266,6 +266,25 @@ config CRYPTO_DEV_NIAGARA2
 	  Group, which can perform encryption, decryption, hashing,
 	  checksumming, and raw copies.
 
+config CRYPTO_DEV_SL3516
+	tristate "Stormlink SL3516 crypto offloader"
+	select CRYPTO_SKCIPHER
+	select CRYPTO_ENGINE
+	select CRYPTO_ECB
+	select CRYPTO_AES
+	select HW_RANDOM
+	help
+	  This option allows you to have support for SL3516 crypto offloader.
+
+config CRYPTO_DEV_SL3516_DEBUG
+	bool "Enable SL3516 stats"
+	depends on CRYPTO_DEV_SL3516
+	depends on DEBUG_FS
+	help
+	  Say y to enable SL3516 debug stats.
+	  This will create /sys/kernel/debug/sl3516/stats for displaying
+	  the number of requests per algorithm and other internal stats.
+
 config CRYPTO_DEV_HIFN_795X
 	tristate "Driver HIFN 795x crypto accelerator chips"
 	select CRYPTO_LIB_DES

drivers/crypto/Makefile

@@ -38,6 +38,7 @@ obj-$(CONFIG_CRYPTO_DEV_ROCKCHIP) += rockchip/
 obj-$(CONFIG_CRYPTO_DEV_S5P) += s5p-sss.o
 obj-$(CONFIG_CRYPTO_DEV_SA2UL) += sa2ul.o
 obj-$(CONFIG_CRYPTO_DEV_SAHARA) += sahara.o
+obj-$(CONFIG_CRYPTO_DEV_SL3516) += gemini/
 obj-$(CONFIG_ARCH_STM32) += stm32/
 obj-$(CONFIG_CRYPTO_DEV_TALITOS) += talitos.o
 obj-$(CONFIG_CRYPTO_DEV_UX500) += ux500/

drivers/crypto/gemini/Makefile

+obj-$(CONFIG_CRYPTO_DEV_SL3516) += sl3516-ce.o
+sl3516-ce-y += sl3516-ce-core.o sl3516-ce-cipher.o sl3516-ce-rng.o

drivers/crypto/gemini/sl3516-ce-rng.c

+// 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);
+}