1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2020 Fuzhou Rockchip Electronics Co., Ltd
4 */
5 #include <asm/arch-rockchip/hardware.h>
6 #include <asm/io.h>
7 #include <common.h>
8 #include <dm.h>
9 #include <linux/bitops.h>
10 #include <linux/iopoll.h>
11 #include <linux/string.h>
12 #include <rng.h>
13
14 #define RK_HW_RNG_MAX 32
15
16 #define _SBF(s, v) ((v) << (s))
17
18 /* start of CRYPTO V1 register define */
19 #define CRYPTO_V1_CTRL 0x0008
20 #define CRYPTO_V1_RNG_START BIT(8)
21 #define CRYPTO_V1_RNG_FLUSH BIT(9)
22
23 #define CRYPTO_V1_TRNG_CTRL 0x0200
24 #define CRYPTO_V1_OSC_ENABLE BIT(16)
25 #define CRYPTO_V1_TRNG_SAMPLE_PERIOD(x) (x)
26
27 #define CRYPTO_V1_TRNG_DOUT_0 0x0204
28 /* end of CRYPTO V1 register define */
29
30 /* start of CRYPTO V2 register define */
31 #define CRYPTO_V2_RNG_CTL 0x0400
32 #define CRYPTO_V2_RNG_64_BIT_LEN _SBF(4, 0x00)
33 #define CRYPTO_V2_RNG_128_BIT_LEN _SBF(4, 0x01)
34 #define CRYPTO_V2_RNG_192_BIT_LEN _SBF(4, 0x02)
35 #define CRYPTO_V2_RNG_256_BIT_LEN _SBF(4, 0x03)
36 #define CRYPTO_V2_RNG_FATESY_SOC_RING _SBF(2, 0x00)
37 #define CRYPTO_V2_RNG_SLOWER_SOC_RING_0 _SBF(2, 0x01)
38 #define CRYPTO_V2_RNG_SLOWER_SOC_RING_1 _SBF(2, 0x02)
39 #define CRYPTO_V2_RNG_SLOWEST_SOC_RING _SBF(2, 0x03)
40 #define CRYPTO_V2_RNG_ENABLE BIT(1)
41 #define CRYPTO_V2_RNG_START BIT(0)
42 #define CRYPTO_V2_RNG_SAMPLE_CNT 0x0404
43 #define CRYPTO_V2_RNG_DOUT_0 0x0410
44 /* end of CRYPTO V2 register define */
45
46 #define RK_RNG_TIME_OUT 50000 /* max 50ms */
47
48 struct rk_rng_soc_data {
49 int (*rk_rng_read)(struct udevice *dev, void *data, size_t len);
50 };
51
52 struct rk_rng_plat {
53 fdt_addr_t base;
54 struct rk_rng_soc_data *soc_data;
55 };
56
rk_rng_read_regs(fdt_addr_t addr,void * buf,size_t size)57 static int rk_rng_read_regs(fdt_addr_t addr, void *buf, size_t size)
58 {
59 u32 count = RK_HW_RNG_MAX / sizeof(u32);
60 u32 reg, tmp_len;
61
62 if (size > RK_HW_RNG_MAX)
63 return -EINVAL;
64
65 while (size && count) {
66 reg = readl(addr);
67 tmp_len = min(size, sizeof(u32));
68 memcpy(buf, ®, tmp_len);
69 addr += sizeof(u32);
70 buf += tmp_len;
71 size -= tmp_len;
72 count--;
73 }
74
75 return 0;
76 }
77
rk_v1_rng_read(struct udevice * dev,void * data,size_t len)78 static int rk_v1_rng_read(struct udevice *dev, void *data, size_t len)
79 {
80 struct rk_rng_plat *pdata = dev_get_priv(dev);
81 u32 reg = 0;
82 int retval;
83
84 if (len > RK_HW_RNG_MAX)
85 return -EINVAL;
86
87 /* enable osc_ring to get entropy, sample period is set as 100 */
88 writel(CRYPTO_V1_OSC_ENABLE | CRYPTO_V1_TRNG_SAMPLE_PERIOD(100),
89 pdata->base + CRYPTO_V1_TRNG_CTRL);
90
91 rk_clrsetreg(pdata->base + CRYPTO_V1_CTRL, CRYPTO_V1_RNG_START,
92 CRYPTO_V1_RNG_START);
93
94 retval = readl_poll_timeout(pdata->base + CRYPTO_V1_CTRL, reg,
95 !(reg & CRYPTO_V1_RNG_START),
96 RK_RNG_TIME_OUT);
97 if (retval)
98 goto exit;
99
100 rk_rng_read_regs(pdata->base + CRYPTO_V1_TRNG_DOUT_0, data, len);
101
102 exit:
103 /* close TRNG */
104 rk_clrreg(pdata->base + CRYPTO_V1_CTRL, CRYPTO_V1_RNG_START);
105
106 return 0;
107 }
108
rk_v2_rng_read(struct udevice * dev,void * data,size_t len)109 static int rk_v2_rng_read(struct udevice *dev, void *data, size_t len)
110 {
111 struct rk_rng_plat *pdata = dev_get_priv(dev);
112 u32 reg = 0;
113 int retval;
114
115 if (len > RK_HW_RNG_MAX)
116 return -EINVAL;
117
118 /* enable osc_ring to get entropy, sample period is set as 100 */
119 writel(100, pdata->base + CRYPTO_V2_RNG_SAMPLE_CNT);
120
121 reg |= CRYPTO_V2_RNG_256_BIT_LEN;
122 reg |= CRYPTO_V2_RNG_SLOWER_SOC_RING_0;
123 reg |= CRYPTO_V2_RNG_ENABLE;
124 reg |= CRYPTO_V2_RNG_START;
125
126 rk_clrsetreg(pdata->base + CRYPTO_V2_RNG_CTL, 0xffff, reg);
127
128 retval = readl_poll_timeout(pdata->base + CRYPTO_V2_RNG_CTL, reg,
129 !(reg & CRYPTO_V2_RNG_START),
130 RK_RNG_TIME_OUT);
131 if (retval)
132 goto exit;
133
134 rk_rng_read_regs(pdata->base + CRYPTO_V2_RNG_DOUT_0, data, len);
135
136 exit:
137 /* close TRNG */
138 rk_clrreg(pdata->base + CRYPTO_V2_RNG_CTL, 0xffff);
139
140 return retval;
141 }
142
rockchip_rng_read(struct udevice * dev,void * data,size_t len)143 static int rockchip_rng_read(struct udevice *dev, void *data, size_t len)
144 {
145 unsigned char *buf = data;
146 unsigned int i;
147 int ret = -EIO;
148
149 struct rk_rng_plat *pdata = dev_get_priv(dev);
150
151 if (!len)
152 return 0;
153
154 if (!pdata->soc_data || !pdata->soc_data->rk_rng_read)
155 return -EINVAL;
156
157 for (i = 0; i < len / RK_HW_RNG_MAX; i++, buf += RK_HW_RNG_MAX) {
158 ret = pdata->soc_data->rk_rng_read(dev, buf, RK_HW_RNG_MAX);
159 if (ret)
160 goto exit;
161 }
162
163 if (len % RK_HW_RNG_MAX)
164 ret = pdata->soc_data->rk_rng_read(dev, buf,
165 len % RK_HW_RNG_MAX);
166
167 exit:
168 return ret;
169 }
170
rockchip_rng_of_to_plat(struct udevice * dev)171 static int rockchip_rng_of_to_plat(struct udevice *dev)
172 {
173 struct rk_rng_plat *pdata = dev_get_priv(dev);
174
175 memset(pdata, 0x00, sizeof(*pdata));
176
177 pdata->base = (fdt_addr_t)dev_read_addr_ptr(dev);
178 if (!pdata->base)
179 return -ENOMEM;
180
181 return 0;
182 }
183
rockchip_rng_probe(struct udevice * dev)184 static int rockchip_rng_probe(struct udevice *dev)
185 {
186 struct rk_rng_plat *pdata = dev_get_priv(dev);
187
188 pdata->soc_data = (struct rk_rng_soc_data *)dev_get_driver_data(dev);
189
190 return 0;
191 }
192
193 static const struct rk_rng_soc_data rk_rng_v1_soc_data = {
194 .rk_rng_read = rk_v1_rng_read,
195 };
196
197 static const struct rk_rng_soc_data rk_rng_v2_soc_data = {
198 .rk_rng_read = rk_v2_rng_read,
199 };
200
201 static const struct dm_rng_ops rockchip_rng_ops = {
202 .read = rockchip_rng_read,
203 };
204
205 static const struct udevice_id rockchip_rng_match[] = {
206 {
207 .compatible = "rockchip,cryptov1-rng",
208 .data = (ulong)&rk_rng_v1_soc_data,
209 },
210 {
211 .compatible = "rockchip,cryptov2-rng",
212 .data = (ulong)&rk_rng_v2_soc_data,
213 },
214 {},
215 };
216
217 U_BOOT_DRIVER(rockchip_rng) = {
218 .name = "rockchip-rng",
219 .id = UCLASS_RNG,
220 .of_match = rockchip_rng_match,
221 .ops = &rockchip_rng_ops,
222 .probe = rockchip_rng_probe,
223 .of_to_plat = rockchip_rng_of_to_plat,
224 .priv_auto = sizeof(struct rk_rng_plat),
225 };
226