xref: /openbmc/u-boot/drivers/crypto/aspeed_acry.c (revision 81930bd2)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright ASPEED Technology Inc.
4  */
5 #include <config.h>
6 #include <common.h>
7 #include <clk.h>
8 #include <dm.h>
9 #include <asm/types.h>
10 #include <asm/io.h>
11 #include <dm/device.h>
12 #include <dm/fdtaddr.h>
13 #include <linux/delay.h>
14 #include <u-boot/rsa-mod-exp.h>
15 
16 /* ACRY register offsets */
17 #define ACRY_CTRL1		0x00
18 #define   ACRY_CTRL1_RSA_DMA		BIT(1)
19 #define   ACRY_CTRL1_RSA_START		BIT(0)
20 #define ACRY_CTRL2		0x44
21 #define ACRY_CTRL3		0x48
22 #define   ACRY_CTRL3_SRAM_AHB_ACCESS	BIT(8)
23 #define   ACRY_CTRL3_ECC_RSA_MODE_MASK	GENMASK(5, 4)
24 #define   ACRY_CTRL3_ECC_RSA_MODE_SHIFT	4
25 #define ACRY_DMA_DRAM_SADDR	0x4c
26 #define ACRY_DMA_DMEM_TADDR	0x50
27 #define   ACRY_DMA_DMEM_TADDR_LEN_MASK	GENMASK(15, 0)
28 #define   ACRY_DMA_DMEM_TADDR_LEN_SHIFT	0
29 #define ACRY_RSA_PARAM		0x58
30 #define   ACRY_RSA_PARAM_EXP_MASK	GENMASK(31, 16)
31 #define   ACRY_RSA_PARAM_EXP_SHIFT	16
32 #define   ACRY_RSA_PARAM_MOD_MASK	GENMASK(15, 0)
33 #define   ACRY_RSA_PARAM_MOD_SHIFT	0
34 #define ACRY_RSA_INT_EN		0x3f8
35 #define   ACRY_RSA_INT_EN_RSA_READY	BIT(2)
36 #define   ACRY_RSA_INT_EN_RSA_CMPLT	BIT(1)
37 #define ACRY_RSA_INT_STS	0x3fc
38 #define   ACRY_RSA_INT_STS_RSA_READY	BIT(2)
39 #define   ACRY_RSA_INT_STS_RSA_CMPLT	BIT(1)
40 
41 /* misc. constant */
42 #define ACRY_ECC_MODE	2
43 #define ACRY_RSA_MODE	3
44 #define ACRY_CTX_BUFSZ	0x600
45 
46 struct aspeed_acry {
47 	phys_addr_t base;
48 	phys_addr_t sram_base; /* internal sram */
49 	struct clk clk;
50 };
51 
52 static int aspeed_acry_mod_exp(struct udevice *dev, const uint8_t *sig, uint32_t sig_len,
53 			       struct key_prop *prop, uint8_t *out)
54 {
55 	int i, j;
56 	u8 *ctx;
57 	u8 *ptr;
58 	u32 reg;
59 	struct aspeed_acry *acry = dev_get_priv(dev);
60 
61 	ctx = memalign(16, ACRY_CTX_BUFSZ);
62 	if (!ctx)
63 		return -ENOMEM;
64 
65 	memset(ctx, 0, ACRY_CTX_BUFSZ);
66 
67 	ptr = (u8 *)prop->public_exponent;
68 	for (i = prop->exp_len - 1, j = 0; i >= 0; --i) {
69 		ctx[j] = ptr[i];
70 		j++;
71 		j = (j % 16) ? j : j + 32;
72 	}
73 
74 	ptr = (u8 *)prop->modulus;
75 	for (i = (prop->num_bits >> 3) - 1, j = 0; i >= 0; --i) {
76 		ctx[j + 16] = ptr[i];
77 		j++;
78 		j = (j % 16) ? j : j + 32;
79 	}
80 
81 	ptr = (u8 *)sig;
82 	for (i = sig_len - 1, j = 0; i >= 0; --i) {
83 		ctx[j + 32] = ptr[i];
84 		j++;
85 		j = (j % 16) ? j : j + 32;
86 	}
87 
88 	writel((u32)ctx, acry->base + ACRY_DMA_DRAM_SADDR);
89 
90 	reg = (((prop->exp_len << 3) << ACRY_RSA_PARAM_EXP_SHIFT) & ACRY_RSA_PARAM_EXP_MASK) |
91 		  ((prop->num_bits << ACRY_RSA_PARAM_MOD_SHIFT) & ACRY_RSA_PARAM_MOD_MASK);
92 	writel(reg, acry->base + ACRY_RSA_PARAM);
93 
94 	reg = (ACRY_CTX_BUFSZ << ACRY_DMA_DMEM_TADDR_LEN_SHIFT) & ACRY_DMA_DMEM_TADDR_LEN_MASK;
95 	writel(reg, acry->base + ACRY_DMA_DMEM_TADDR);
96 
97 	reg = (ACRY_RSA_MODE << ACRY_CTRL3_ECC_RSA_MODE_SHIFT) & ACRY_CTRL3_ECC_RSA_MODE_MASK;
98 	writel(reg, acry->base + ACRY_CTRL3);
99 
100 	writel(ACRY_CTRL1_RSA_DMA | ACRY_CTRL1_RSA_START, acry->base + ACRY_CTRL1);
101 
102 	/* polling RSA status */
103 	while (1) {
104 		reg = readl(acry->base + ACRY_RSA_INT_STS);
105 		if ((reg & ACRY_RSA_INT_STS_RSA_READY) && (reg & ACRY_RSA_INT_STS_RSA_CMPLT)) {
106 			writel(reg, acry->base + ACRY_RSA_INT_STS);
107 			break;
108 		}
109 		udelay(20);
110 	}
111 
112 	/* grant SRAM access permission to CPU */
113 	writel(0x0, acry->base + ACRY_CTRL1);
114 	writel(ACRY_CTRL3_SRAM_AHB_ACCESS, acry->base + ACRY_CTRL3);
115 	udelay(20);
116 
117 	for (i = (prop->num_bits / 8) - 1, j = 0; i >= 0; --i) {
118 		out[i] = readb(acry->sram_base + (j + 32));
119 		j++;
120 		j = (j % 16) ? j : j + 32;
121 	}
122 
123 	free(ctx);
124 
125 	return 0;
126 }
127 
128 static int aspeed_acry_probe(struct udevice *dev)
129 {
130 	struct aspeed_acry *acry = dev_get_priv(dev);
131 	int ret;
132 
133 	ret = clk_get_by_index(dev, 0, &acry->clk);
134 	if (ret < 0) {
135 		debug("Can't get clock for %s: %d\n", dev->name, ret);
136 		return ret;
137 	}
138 
139 	ret = clk_enable(&acry->clk);
140 	if (ret) {
141 		debug("Failed to enable acry clock (%d)\n", ret);
142 		return ret;
143 	}
144 
145 	acry->base = devfdt_get_addr_index(dev, 0);
146 	if (acry->base == FDT_ADDR_T_NONE) {
147 		debug("Failed to get acry base\n");
148 		return acry->base;
149 	}
150 
151 	acry->sram_base = devfdt_get_addr_index(dev, 1);
152 	if (acry->sram_base == FDT_ADDR_T_NONE) {
153 		debug("Failed to get acry SRAM base\n");
154 		return acry->sram_base;
155 	}
156 
157 	/* grant SRAM access permission to CPU */
158 	writel(ACRY_CTRL3_SRAM_AHB_ACCESS, acry->base + ACRY_CTRL3);
159 
160 	return ret;
161 }
162 
163 static int aspeed_acry_remove(struct udevice *dev)
164 {
165 	struct aspeed_acry *acry = dev_get_priv(dev);
166 
167 	clk_disable(&acry->clk);
168 
169 	return 0;
170 }
171 
172 static const struct mod_exp_ops aspeed_acry_ops = {
173 	.mod_exp = aspeed_acry_mod_exp,
174 };
175 
176 static const struct udevice_id aspeed_acry_ids[] = {
177 	{ .compatible = "aspeed,ast2600-acry" },
178 	{ }
179 };
180 
181 U_BOOT_DRIVER(aspeed_acry) = {
182 	.name = "aspeed_acry",
183 	.id = UCLASS_MOD_EXP,
184 	.of_match = aspeed_acry_ids,
185 	.probe = aspeed_acry_probe,
186 	.remove = aspeed_acry_remove,
187 	.priv_auto_alloc_size = sizeof(struct aspeed_acry),
188 	.ops = &aspeed_acry_ops,
189 	.flags = DM_FLAG_PRE_RELOC,
190 };
191