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8#include <common.h>
9#include <dm.h>
10#include <linux/delay.h>
11#include <rng.h>
12#include <asm/io.h>
13
14#define usleep_range(a, b) udelay((b))
15
16#define RNG_CTRL_OFFSET 0x00
17#define RNG_CTRL_RNG_RBGEN_MASK 0x00001FFF
18#define RNG_CTRL_RNG_RBGEN_ENABLE 0x00000001
19#define RNG_CTRL_RNG_RBGEN_DISABLE 0x00000000
20
21#define RNG_SOFT_RESET_OFFSET 0x04
22#define RNG_SOFT_RESET 0x00000001
23
24#define RBG_SOFT_RESET_OFFSET 0x08
25#define RBG_SOFT_RESET 0x00000001
26
27#define RNG_INT_STATUS_OFFSET 0x18
28#define RNG_INT_STATUS_MASTER_FAIL_LOCKOUT_IRQ_MASK 0x80000000
29#define RNG_INT_STATUS_NIST_FAIL_IRQ_MASK 0x00000020
30
31#define RNG_FIFO_DATA_OFFSET 0x20
32
33#define RNG_FIFO_COUNT_OFFSET 0x24
34#define RNG_FIFO_COUNT_RNG_FIFO_COUNT_MASK 0x000000FF
35
36struct iproc_rng200_plat {
37 void __iomem *base;
38};
39
40static void iproc_rng200_enable(struct iproc_rng200_plat *pdata, bool enable)
41{
42 void __iomem *rng_base = pdata->base;
43 u32 val;
44
45 val = readl(rng_base + RNG_CTRL_OFFSET);
46 val &= ~RNG_CTRL_RNG_RBGEN_MASK;
47 if (enable)
48 val |= RNG_CTRL_RNG_RBGEN_ENABLE;
49 else
50 val &= ~RNG_CTRL_RNG_RBGEN_ENABLE;
51
52 writel(val, rng_base + RNG_CTRL_OFFSET);
53}
54
55static void iproc_rng200_restart(struct iproc_rng200_plat *pdata)
56{
57 void __iomem *rng_base = pdata->base;
58 u32 val;
59
60 iproc_rng200_enable(pdata, false);
61
62
63 writel(0xFFFFFFFFUL, rng_base + RNG_INT_STATUS_OFFSET);
64
65
66 val = readl(rng_base + RBG_SOFT_RESET_OFFSET);
67 val |= RBG_SOFT_RESET;
68 writel(val, rng_base + RBG_SOFT_RESET_OFFSET);
69
70 val = readl(rng_base + RNG_SOFT_RESET_OFFSET);
71 val |= RNG_SOFT_RESET;
72 writel(val, rng_base + RNG_SOFT_RESET_OFFSET);
73
74 val = readl(rng_base + RNG_SOFT_RESET_OFFSET);
75 val &= ~RNG_SOFT_RESET;
76 writel(val, rng_base + RNG_SOFT_RESET_OFFSET);
77
78 val = readl(rng_base + RBG_SOFT_RESET_OFFSET);
79 val &= ~RBG_SOFT_RESET;
80 writel(val, rng_base + RBG_SOFT_RESET_OFFSET);
81
82 iproc_rng200_enable(pdata, true);
83}
84
85static int iproc_rng200_read(struct udevice *dev, void *data, size_t len)
86{
87 struct iproc_rng200_plat *priv = dev_get_plat(dev);
88 char *buf = (char *)data;
89 u32 num_remaining = len;
90 u32 status;
91
92 #define MAX_RESETS_PER_READ 1
93 u32 num_resets = 0;
94
95 while (num_remaining > 0) {
96
97
98 status = readl(priv->base + RNG_INT_STATUS_OFFSET);
99 if ((status & (RNG_INT_STATUS_MASTER_FAIL_LOCKOUT_IRQ_MASK |
100 RNG_INT_STATUS_NIST_FAIL_IRQ_MASK)) != 0) {
101
102 if (num_resets >= MAX_RESETS_PER_READ)
103 return len - num_remaining;
104
105 iproc_rng200_restart(priv);
106 num_resets++;
107 }
108
109
110 if ((readl(priv->base + RNG_FIFO_COUNT_OFFSET) &
111 RNG_FIFO_COUNT_RNG_FIFO_COUNT_MASK) > 0) {
112
113 if (num_remaining >= sizeof(u32)) {
114
115 *(u32 *)buf = readl(priv->base +
116 RNG_FIFO_DATA_OFFSET);
117 buf += sizeof(u32);
118 num_remaining -= sizeof(u32);
119 } else {
120
121 u32 rnd_number = readl(priv->base +
122 RNG_FIFO_DATA_OFFSET);
123 memcpy(buf, &rnd_number, num_remaining);
124 buf += num_remaining;
125 num_remaining = 0;
126 }
127
128 } else {
129
130 usleep_range(min(num_remaining * 10, 500U), 500);
131 }
132 }
133
134 return 0;
135}
136
137static int iproc_rng200_probe(struct udevice *dev)
138{
139 struct iproc_rng200_plat *priv = dev_get_plat(dev);
140
141 iproc_rng200_enable(priv, true);
142
143 return 0;
144}
145
146static int iproc_rng200_remove(struct udevice *dev)
147{
148 struct iproc_rng200_plat *priv = dev_get_plat(dev);
149
150 iproc_rng200_enable(priv, false);
151
152 return 0;
153}
154
155static int iproc_rng200_of_to_plat(struct udevice *dev)
156{
157 struct iproc_rng200_plat *pdata = dev_get_plat(dev);
158
159 pdata->base = devfdt_map_physmem(dev, sizeof(void *));
160 if (!pdata->base)
161 return -ENODEV;
162
163 return 0;
164}
165
166static const struct dm_rng_ops iproc_rng200_ops = {
167 .read = iproc_rng200_read,
168};
169
170static const struct udevice_id iproc_rng200_rng_match[] = {
171 { .compatible = "brcm,bcm2711-rng200", },
172 { .compatible = "brcm,iproc-rng200", },
173 {},
174};
175
176U_BOOT_DRIVER(iproc_rng200_rng) = {
177 .name = "iproc_rng200-rng",
178 .id = UCLASS_RNG,
179 .of_match = iproc_rng200_rng_match,
180 .ops = &iproc_rng200_ops,
181 .probe = iproc_rng200_probe,
182 .remove = iproc_rng200_remove,
183 .priv_auto = sizeof(struct iproc_rng200_plat),
184 .of_to_plat = iproc_rng200_of_to_plat,
185};
186
