crypto: aspeed: Add AST2600 ACRY support

ACRY is designed to accelerate ECC/RSA digital signature
generation and verification.

Signed-off-by: Chia-Wei Wang <chiawei_wang@aspeedtech.com>

3 files changed, 201 insertions, 0 deletions

diff --git a/drivers/crypto/aspeed/Kconfig b/drivers/crypto/aspeed/Kconfig
index 471c06f986..9bf317177a 100644
--- a/drivers/crypto/aspeed/Kconfig
+++ b/drivers/crypto/aspeed/Kconfig
@@ -8,3 +8,13 @@ config ASPEED_HACE
 	  Enabling this allows the use of SHA operations in hardware without
 	  requiring the SHA software implementations. It also improves performance
 	  and saves code size.
+
+config ASPEED_ACRY
+	bool "ASPEED RSA and ECC Engine"
+	depends on ASPEED_AST2600
+	help
+	 Select this option to enable a driver for using the RSA/ECC engine in
+	 the ASPEED BMC SoCs.
+
+	 Enabling this allows the use of RSA/ECC operations in hardware without requiring the
+	 software implementations. It also improves performance and saves code size.
diff --git a/drivers/crypto/aspeed/Makefile b/drivers/crypto/aspeed/Makefile
index 84e6bfe82a..58b55fc46e 100644
--- a/drivers/crypto/aspeed/Makefile
+++ b/drivers/crypto/aspeed/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_ASPEED_HACE) += aspeed_hace.o
+obj-$(CONFIG_ASPEED_ACRY) += aspeed_acry.o
diff --git a/drivers/crypto/aspeed/aspeed_acry.c b/drivers/crypto/aspeed/aspeed_acry.c
new file mode 100644
index 0000000000..c28cdf374b
--- /dev/null
+++ b/drivers/crypto/aspeed/aspeed_acry.c
@@ -0,0 +1,190 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2021 ASPEED Technology Inc.
+ */
+#include <config.h>
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <asm/types.h>
+#include <asm/io.h>
+#include <dm/device.h>
+#include <dm/fdtaddr.h>
+#include <linux/delay.h>
+#include <u-boot/rsa-mod-exp.h>
+
+/* ACRY register offsets */
+#define ACRY_CTRL1		0x00
+#define   ACRY_CTRL1_RSA_DMA		BIT(1)
+#define   ACRY_CTRL1_RSA_START		BIT(0)
+#define ACRY_CTRL2		0x44
+#define ACRY_CTRL3		0x48
+#define   ACRY_CTRL3_SRAM_AHB_ACCESS	BIT(8)
+#define   ACRY_CTRL3_ECC_RSA_MODE_MASK	GENMASK(5, 4)
+#define   ACRY_CTRL3_ECC_RSA_MODE_SHIFT	4
+#define ACRY_DMA_DRAM_SADDR	0x4c
+#define ACRY_DMA_DMEM_TADDR	0x50
+#define   ACRY_DMA_DMEM_TADDR_LEN_MASK	GENMASK(15, 0)
+#define   ACRY_DMA_DMEM_TADDR_LEN_SHIFT	0
+#define ACRY_RSA_PARAM		0x58
+#define   ACRY_RSA_PARAM_EXP_MASK	GENMASK(31, 16)
+#define   ACRY_RSA_PARAM_EXP_SHIFT	16
+#define   ACRY_RSA_PARAM_MOD_MASK	GENMASK(15, 0)
+#define   ACRY_RSA_PARAM_MOD_SHIFT	0
+#define ACRY_RSA_INT_EN		0x3f8
+#define   ACRY_RSA_INT_EN_RSA_READY	BIT(2)
+#define   ACRY_RSA_INT_EN_RSA_CMPLT	BIT(1)
+#define ACRY_RSA_INT_STS	0x3fc
+#define   ACRY_RSA_INT_STS_RSA_READY	BIT(2)
+#define   ACRY_RSA_INT_STS_RSA_CMPLT	BIT(1)
+
+/* misc. constant */
+#define ACRY_ECC_MODE	2
+#define ACRY_RSA_MODE	3
+#define ACRY_CTX_BUFSZ	0x600
+
+struct aspeed_acry {
+	phys_addr_t base;
+	phys_addr_t sram_base; /* internal sram */
+	struct clk clk;
+};
+
+static int aspeed_acry_mod_exp(struct udevice *dev, const uint8_t *sig, uint32_t sig_len,
+			       struct key_prop *prop, uint8_t *out)
+{
+	int i, j;
+	u8 *ctx;
+	u8 *ptr;
+	u32 reg;
+	struct aspeed_acry *acry = dev_get_priv(dev);
+
+	ctx = memalign(16, ACRY_CTX_BUFSZ);
+	if (!ctx)
+		return -ENOMEM;
+
+	memset(ctx, 0, ACRY_CTX_BUFSZ);
+
+	ptr = (u8 *)prop->public_exponent;
+	for (i = prop->exp_len - 1, j = 0; i >= 0; --i) {
+		ctx[j] = ptr[i];
+		j++;
+		j = (j % 16) ? j : j + 32;
+	}
+
+	ptr = (u8 *)prop->modulus;
+	for (i = (prop->num_bits >> 3) - 1, j = 0; i >= 0; --i) {
+		ctx[j + 16] = ptr[i];
+		j++;
+		j = (j % 16) ? j : j + 32;
+	}
+
+	ptr = (u8 *)sig;
+	for (i = sig_len - 1, j = 0; i >= 0; --i) {
+		ctx[j + 32] = ptr[i];
+		j++;
+		j = (j % 16) ? j : j + 32;
+	}
+
+	writel((u32)ctx, acry->base + ACRY_DMA_DRAM_SADDR);
+
+	reg = (((prop->exp_len << 3) << ACRY_RSA_PARAM_EXP_SHIFT) & ACRY_RSA_PARAM_EXP_MASK) |
+		  ((prop->num_bits << ACRY_RSA_PARAM_MOD_SHIFT) & ACRY_RSA_PARAM_MOD_MASK);
+	writel(reg, acry->base + ACRY_RSA_PARAM);
+
+	reg = (ACRY_CTX_BUFSZ << ACRY_DMA_DMEM_TADDR_LEN_SHIFT) & ACRY_DMA_DMEM_TADDR_LEN_MASK;
+	writel(reg, acry->base + ACRY_DMA_DMEM_TADDR);
+
+	reg = (ACRY_RSA_MODE << ACRY_CTRL3_ECC_RSA_MODE_SHIFT) & ACRY_CTRL3_ECC_RSA_MODE_MASK;
+	writel(reg, acry->base + ACRY_CTRL3);
+
+	writel(ACRY_CTRL1_RSA_DMA | ACRY_CTRL1_RSA_START, acry->base + ACRY_CTRL1);
+
+	/* polling RSA status */
+	while (1) {
+		reg = readl(acry->base + ACRY_RSA_INT_STS);
+		if ((reg & ACRY_RSA_INT_STS_RSA_READY) && (reg & ACRY_RSA_INT_STS_RSA_CMPLT)) {
+			writel(reg, ACRY_RSA_INT_STS);
+			break;
+		}
+		udelay(20);
+	}
+
+	/* grant SRAM access permission to CPU */
+	writel(0x0, acry->base + ACRY_CTRL1);
+	writel(ACRY_CTRL3_SRAM_AHB_ACCESS, acry->base + ACRY_CTRL3);
+	udelay(20);
+
+	for (i = (prop->num_bits / 8) - 1, j = 0; i >= 0; --i) {
+		out[i] = readb(acry->sram_base + (j + 32));
+		j++;
+		j = (j % 16) ? j : j + 32;
+	}
+
+	/* return SRAM access permission to ACRY */
+	writel(0, acry->base + ACRY_CTRL3);
+
+	free(ctx);
+
+	return 0;
+}
+
+static int aspeed_acry_probe(struct udevice *dev)
+{
+	struct aspeed_acry *acry = dev_get_priv(dev);
+	int ret;
+
+	ret = clk_get_by_index(dev, 0, &acry->clk);
+	if (ret < 0) {
+		debug("Can't get clock for %s: %d\n", dev->name, ret);
+		return ret;
+	}
+
+	ret = clk_enable(&acry->clk);
+	if (ret) {
+		debug("Failed to enable acry clock (%d)\n", ret);
+		return ret;
+	}
+
+	acry->base = devfdt_get_addr_index(dev, 0);
+	if (acry->base == FDT_ADDR_T_NONE) {
+		debug("Failed to get acry base\n");
+		return acry->base;
+	}
+
+	acry->sram_base = devfdt_get_addr_index(dev, 1);
+	if (acry->sram_base == FDT_ADDR_T_NONE) {
+		debug("Failed to get acry SRAM base\n");
+		return acry->sram_base;
+	}
+
+	return ret;
+}
+
+static int aspeed_acry_remove(struct udevice *dev)
+{
+	struct aspeed_acry *acry = dev_get_priv(dev);
+
+	clk_disable(&acry->clk);
+
+	return 0;
+}
+
+static const struct mod_exp_ops aspeed_acry_ops = {
+	.mod_exp = aspeed_acry_mod_exp,
+};
+
+static const struct udevice_id aspeed_acry_ids[] = {
+	{ .compatible = "aspeed,ast2600-acry" },
+	{ }
+};
+
+U_BOOT_DRIVER(aspeed_acry) = {
+	.name = "aspeed_acry",
+	.id = UCLASS_MOD_EXP,
+	.of_match = aspeed_acry_ids,
+	.probe = aspeed_acry_probe,
+	.remove = aspeed_acry_remove,
+	.priv_auto = sizeof(struct aspeed_acry),
+	.ops = &aspeed_acry_ops,
+	.flags = DM_FLAG_PRE_RELOC,
+};