crypto: sunxi-ss - Add Allwinner Security System crypto accelerator

Add support for the Security System included in Allwinner SoC A20.
The Security System is a hardware cryptographic accelerator that support:
- MD5 and SHA1 hash algorithms
- AES block cipher in CBC/ECB mode with 128/196/256bits keys.
- DES and 3DES block cipher in CBC/ECB mode

Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/sunxi-ss/sun4i-ss-core.c b/drivers/crypto/sunxi-ss/sun4i-ss-core.c
new file mode 100644
index 0000000..0b79b58
--- /dev/null
+++ b/drivers/crypto/sunxi-ss/sun4i-ss-core.c
@@ -0,0 +1,403 @@
+/*
+ * sun4i-ss-core.c - hardware cryptographic accelerator for Allwinner A20 SoC
+ *
+ * Copyright (C) 2013-2015 Corentin LABBE <clabbe.montjoie@gmail.com>
+ *
+ * Core file which registers crypto algorithms supported by the SS.
+ *
+ * You could find a link for the datasheet in Documentation/arm/sunxi/README
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#include <linux/clk.h>
+#include <linux/crypto.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <crypto/scatterwalk.h>
+#include <linux/scatterlist.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+
+#include "sun4i-ss.h"
+
+static struct sun4i_ss_alg_template ss_algs[] = {
+{       .type = CRYPTO_ALG_TYPE_AHASH,
+	.mode = SS_OP_MD5,
+	.alg.hash = {
+		.init = sun4i_hash_init,
+		.update = sun4i_hash_update,
+		.final = sun4i_hash_final,
+		.finup = sun4i_hash_finup,
+		.digest = sun4i_hash_digest,
+		.export = sun4i_hash_export_md5,
+		.import = sun4i_hash_import_md5,
+		.halg = {
+			.digestsize = MD5_DIGEST_SIZE,
+			.base = {
+				.cra_name = "md5",
+				.cra_driver_name = "md5-sun4i-ss",
+				.cra_priority = 300,
+				.cra_alignmask = 3,
+				.cra_flags = CRYPTO_ALG_TYPE_AHASH,
+				.cra_blocksize = MD5_HMAC_BLOCK_SIZE,
+				.cra_ctxsize = sizeof(struct sun4i_req_ctx),
+				.cra_module = THIS_MODULE,
+				.cra_type = &crypto_ahash_type,
+				.cra_init = sun4i_hash_crainit
+			}
+		}
+	}
+},
+{       .type = CRYPTO_ALG_TYPE_AHASH,
+	.mode = SS_OP_SHA1,
+	.alg.hash = {
+		.init = sun4i_hash_init,
+		.update = sun4i_hash_update,
+		.final = sun4i_hash_final,
+		.finup = sun4i_hash_finup,
+		.digest = sun4i_hash_digest,
+		.export = sun4i_hash_export_sha1,
+		.import = sun4i_hash_import_sha1,
+		.halg = {
+			.digestsize = SHA1_DIGEST_SIZE,
+			.base = {
+				.cra_name = "sha1",
+				.cra_driver_name = "sha1-sun4i-ss",
+				.cra_priority = 300,
+				.cra_alignmask = 3,
+				.cra_flags = CRYPTO_ALG_TYPE_AHASH,
+				.cra_blocksize = SHA1_BLOCK_SIZE,
+				.cra_ctxsize = sizeof(struct sun4i_req_ctx),
+				.cra_module = THIS_MODULE,
+				.cra_type = &crypto_ahash_type,
+				.cra_init = sun4i_hash_crainit
+			}
+		}
+	}
+},
+{       .type = CRYPTO_ALG_TYPE_ABLKCIPHER,
+	.alg.crypto = {
+		.cra_name = "cbc(aes)",
+		.cra_driver_name = "cbc-aes-sun4i-ss",
+		.cra_priority = 300,
+		.cra_blocksize = AES_BLOCK_SIZE,
+		.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER,
+		.cra_ctxsize = sizeof(struct sun4i_tfm_ctx),
+		.cra_module = THIS_MODULE,
+		.cra_alignmask = 3,
+		.cra_type = &crypto_ablkcipher_type,
+		.cra_init = sun4i_ss_cipher_init,
+		.cra_ablkcipher = {
+			.min_keysize	= AES_MIN_KEY_SIZE,
+			.max_keysize	= AES_MAX_KEY_SIZE,
+			.ivsize		= AES_BLOCK_SIZE,
+			.setkey         = sun4i_ss_aes_setkey,
+			.encrypt        = sun4i_ss_cbc_aes_encrypt,
+			.decrypt        = sun4i_ss_cbc_aes_decrypt,
+		}
+	}
+},
+{       .type = CRYPTO_ALG_TYPE_ABLKCIPHER,
+	.alg.crypto = {
+		.cra_name = "ecb(aes)",
+		.cra_driver_name = "ecb-aes-sun4i-ss",
+		.cra_priority = 300,
+		.cra_blocksize = AES_BLOCK_SIZE,
+		.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER,
+		.cra_ctxsize = sizeof(struct sun4i_tfm_ctx),
+		.cra_module = THIS_MODULE,
+		.cra_alignmask = 3,
+		.cra_type = &crypto_ablkcipher_type,
+		.cra_init = sun4i_ss_cipher_init,
+		.cra_ablkcipher = {
+			.min_keysize	= AES_MIN_KEY_SIZE,
+			.max_keysize	= AES_MAX_KEY_SIZE,
+			.ivsize		= AES_BLOCK_SIZE,
+			.setkey         = sun4i_ss_aes_setkey,
+			.encrypt        = sun4i_ss_ecb_aes_encrypt,
+			.decrypt        = sun4i_ss_ecb_aes_decrypt,
+		}
+	}
+},
+{       .type = CRYPTO_ALG_TYPE_ABLKCIPHER,
+	.alg.crypto = {
+		.cra_name = "cbc(des)",
+		.cra_driver_name = "cbc-des-sun4i-ss",
+		.cra_priority = 300,
+		.cra_blocksize = DES_BLOCK_SIZE,
+		.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER,
+		.cra_ctxsize = sizeof(struct sun4i_req_ctx),
+		.cra_module = THIS_MODULE,
+		.cra_alignmask = 3,
+		.cra_type = &crypto_ablkcipher_type,
+		.cra_init = sun4i_ss_cipher_init,
+		.cra_u.ablkcipher = {
+			.min_keysize    = DES_KEY_SIZE,
+			.max_keysize    = DES_KEY_SIZE,
+			.ivsize         = DES_BLOCK_SIZE,
+			.setkey         = sun4i_ss_des_setkey,
+			.encrypt        = sun4i_ss_cbc_des_encrypt,
+			.decrypt        = sun4i_ss_cbc_des_decrypt,
+		}
+	}
+},
+{       .type = CRYPTO_ALG_TYPE_ABLKCIPHER,
+	.alg.crypto = {
+		.cra_name = "ecb(des)",
+		.cra_driver_name = "ecb-des-sun4i-ss",
+		.cra_priority = 300,
+		.cra_blocksize = DES_BLOCK_SIZE,
+		.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER,
+		.cra_ctxsize = sizeof(struct sun4i_req_ctx),
+		.cra_module = THIS_MODULE,
+		.cra_alignmask = 3,
+		.cra_type = &crypto_ablkcipher_type,
+		.cra_init = sun4i_ss_cipher_init,
+		.cra_u.ablkcipher = {
+			.min_keysize    = DES_KEY_SIZE,
+			.max_keysize    = DES_KEY_SIZE,
+			.setkey         = sun4i_ss_des_setkey,
+			.encrypt        = sun4i_ss_ecb_des_encrypt,
+			.decrypt        = sun4i_ss_ecb_des_decrypt,
+		}
+	}
+},
+{       .type = CRYPTO_ALG_TYPE_ABLKCIPHER,
+	.alg.crypto = {
+			.cra_name = "cbc(des3_ede)",
+			.cra_driver_name = "cbc-des3-sun4i-ss",
+			.cra_priority = 300,
+			.cra_blocksize = DES3_EDE_BLOCK_SIZE,
+			.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER,
+			.cra_ctxsize = sizeof(struct sun4i_req_ctx),
+			.cra_module = THIS_MODULE,
+			.cra_alignmask = 3,
+			.cra_type = &crypto_ablkcipher_type,
+			.cra_init = sun4i_ss_cipher_init,
+			.cra_u.ablkcipher = {
+				.min_keysize    = DES3_EDE_KEY_SIZE,
+				.max_keysize    = DES3_EDE_KEY_SIZE,
+				.ivsize         = DES3_EDE_BLOCK_SIZE,
+				.setkey         = sun4i_ss_des3_setkey,
+				.encrypt        = sun4i_ss_cbc_des3_encrypt,
+				.decrypt        = sun4i_ss_cbc_des3_decrypt,
+		}
+	}
+},
+{       .type = CRYPTO_ALG_TYPE_ABLKCIPHER,
+	.alg.crypto = {
+			.cra_name = "ecb(des3_ede)",
+			.cra_driver_name = "ecb-des3-sun4i-ss",
+			.cra_priority = 300,
+			.cra_blocksize = DES3_EDE_BLOCK_SIZE,
+			.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER,
+			.cra_ctxsize = sizeof(struct sun4i_req_ctx),
+			.cra_module = THIS_MODULE,
+			.cra_alignmask = 3,
+			.cra_type = &crypto_ablkcipher_type,
+			.cra_init = sun4i_ss_cipher_init,
+			.cra_u.ablkcipher = {
+				.min_keysize    = DES3_EDE_KEY_SIZE,
+				.max_keysize    = DES3_EDE_KEY_SIZE,
+				.ivsize         = DES3_EDE_BLOCK_SIZE,
+				.setkey         = sun4i_ss_des3_setkey,
+				.encrypt        = sun4i_ss_ecb_des3_encrypt,
+				.decrypt        = sun4i_ss_ecb_des3_decrypt,
+		}
+	}
+},
+};
+
+static int sun4i_ss_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	u32 v;
+	int err, i;
+	unsigned long cr;
+	const unsigned long cr_ahb = 24 * 1000 * 1000;
+	const unsigned long cr_mod = 150 * 1000 * 1000;
+	struct sun4i_ss_ctx *ss;
+
+	if (!pdev->dev.of_node)
+		return -ENODEV;
+
+	ss = devm_kzalloc(&pdev->dev, sizeof(*ss), GFP_KERNEL);
+	if (!ss)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ss->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(ss->base)) {
+		dev_err(&pdev->dev, "Cannot request MMIO\n");
+		return PTR_ERR(ss->base);
+	}
+
+	ss->ssclk = devm_clk_get(&pdev->dev, "mod");
+	if (IS_ERR(ss->ssclk)) {
+		err = PTR_ERR(ss->ssclk);
+		dev_err(&pdev->dev, "Cannot get SS clock err=%d\n", err);
+		return err;
+	}
+	dev_dbg(&pdev->dev, "clock ss acquired\n");
+
+	ss->busclk = devm_clk_get(&pdev->dev, "ahb");
+	if (IS_ERR(ss->busclk)) {
+		err = PTR_ERR(ss->busclk);
+		dev_err(&pdev->dev, "Cannot get AHB SS clock err=%d\n", err);
+		return err;
+	}
+	dev_dbg(&pdev->dev, "clock ahb_ss acquired\n");
+
+	/* Enable both clocks */
+	err = clk_prepare_enable(ss->busclk);
+	if (err != 0) {
+		dev_err(&pdev->dev, "Cannot prepare_enable busclk\n");
+		return err;
+	}
+	err = clk_prepare_enable(ss->ssclk);
+	if (err != 0) {
+		dev_err(&pdev->dev, "Cannot prepare_enable ssclk\n");
+		goto error_ssclk;
+	}
+
+	/*
+	 * Check that clock have the correct rates given in the datasheet
+	 * Try to set the clock to the maximum allowed
+	 */
+	err = clk_set_rate(ss->ssclk, cr_mod);
+	if (err != 0) {
+		dev_err(&pdev->dev, "Cannot set clock rate to ssclk\n");
+		goto error_clk;
+	}
+
+	/*
+	 * The only impact on clocks below requirement are bad performance,
+	 * so do not print "errors"
+	 * warn on Overclocked clocks
+	 */
+	cr = clk_get_rate(ss->busclk);
+	if (cr >= cr_ahb)
+		dev_dbg(&pdev->dev, "Clock bus %lu (%lu MHz) (must be >= %lu)\n",
+			cr, cr / 1000000, cr_ahb);
+	else
+		dev_warn(&pdev->dev, "Clock bus %lu (%lu MHz) (must be >= %lu)\n",
+			 cr, cr / 1000000, cr_ahb);
+
+	cr = clk_get_rate(ss->ssclk);
+	if (cr <= cr_mod)
+		if (cr < cr_mod)
+			dev_warn(&pdev->dev, "Clock ss %lu (%lu MHz) (must be <= %lu)\n",
+				 cr, cr / 1000000, cr_mod);
+		else
+			dev_dbg(&pdev->dev, "Clock ss %lu (%lu MHz) (must be <= %lu)\n",
+				cr, cr / 1000000, cr_mod);
+	else
+		dev_warn(&pdev->dev, "Clock ss is at %lu (%lu MHz) (must be <= %lu)\n",
+			 cr, cr / 1000000, cr_mod);
+
+	/*
+	 * Datasheet named it "Die Bonding ID"
+	 * I expect to be a sort of Security System Revision number.
+	 * Since the A80 seems to have an other version of SS
+	 * this info could be useful
+	 */
+	writel(SS_ENABLED, ss->base + SS_CTL);
+	v = readl(ss->base + SS_CTL);
+	v >>= 16;
+	v &= 0x07;
+	dev_info(&pdev->dev, "Die ID %d\n", v);
+	writel(0, ss->base + SS_CTL);
+
+	ss->dev = &pdev->dev;
+
+	spin_lock_init(&ss->slock);
+
+	for (i = 0; i < ARRAY_SIZE(ss_algs); i++) {
+		ss_algs[i].ss = ss;
+		switch (ss_algs[i].type) {
+		case CRYPTO_ALG_TYPE_ABLKCIPHER:
+			err = crypto_register_alg(&ss_algs[i].alg.crypto);
+			if (err != 0) {
+				dev_err(ss->dev, "Fail to register %s\n",
+					ss_algs[i].alg.crypto.cra_name);
+				goto error_alg;
+			}
+			break;
+		case CRYPTO_ALG_TYPE_AHASH:
+			err = crypto_register_ahash(&ss_algs[i].alg.hash);
+			if (err != 0) {
+				dev_err(ss->dev, "Fail to register %s\n",
+					ss_algs[i].alg.hash.halg.base.cra_name);
+				goto error_alg;
+			}
+			break;
+		}
+	}
+	platform_set_drvdata(pdev, ss);
+	return 0;
+error_alg:
+	i--;
+	for (; i >= 0; i--) {
+		switch (ss_algs[i].type) {
+		case CRYPTO_ALG_TYPE_ABLKCIPHER:
+			crypto_unregister_alg(&ss_algs[i].alg.crypto);
+			break;
+		case CRYPTO_ALG_TYPE_AHASH:
+			crypto_unregister_ahash(&ss_algs[i].alg.hash);
+			break;
+		}
+	}
+error_clk:
+	clk_disable_unprepare(ss->ssclk);
+error_ssclk:
+	clk_disable_unprepare(ss->busclk);
+	return err;
+}
+
+static int sun4i_ss_remove(struct platform_device *pdev)
+{
+	int i;
+	struct sun4i_ss_ctx *ss = platform_get_drvdata(pdev);
+
+	for (i = 0; i < ARRAY_SIZE(ss_algs); i++) {
+		switch (ss_algs[i].type) {
+		case CRYPTO_ALG_TYPE_ABLKCIPHER:
+			crypto_unregister_alg(&ss_algs[i].alg.crypto);
+			break;
+		case CRYPTO_ALG_TYPE_AHASH:
+			crypto_unregister_ahash(&ss_algs[i].alg.hash);
+			break;
+		}
+	}
+
+	writel(0, ss->base + SS_CTL);
+	clk_disable_unprepare(ss->busclk);
+	clk_disable_unprepare(ss->ssclk);
+	return 0;
+}
+
+static const struct of_device_id a20ss_crypto_of_match_table[] = {
+	{ .compatible = "allwinner,sun4i-a10-crypto" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, a20ss_crypto_of_match_table);
+
+static struct platform_driver sun4i_ss_driver = {
+	.probe          = sun4i_ss_probe,
+	.remove         = sun4i_ss_remove,
+	.driver         = {
+		.name           = "sun4i-ss",
+		.of_match_table	= a20ss_crypto_of_match_table,
+	},
+};
+
+module_platform_driver(sun4i_ss_driver);
+
+MODULE_DESCRIPTION("Allwinner Security System cryptographic accelerator");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Corentin LABBE <clabbe.montjoie@gmail.com>");