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9#include <linux/device.h>
10#include <linux/io.h>
11#include <linux/iopoll.h>
12#include <linux/module.h>
13#include <linux/nvmem-provider.h>
14#include <linux/of.h>
15#include <linux/of_device.h>
16#include <linux/platform_device.h>
17#include <linux/slab.h>
18#include <linux/random.h>
19
20
21#define SUN8I_SID_PRCTL 0x40
22#define SUN8I_SID_RDKEY 0x60
23
24#define SUN8I_SID_OFFSET_MASK 0x1FF
25#define SUN8I_SID_OFFSET_SHIFT 16
26#define SUN8I_SID_OP_LOCK (0xAC << 8)
27#define SUN8I_SID_READ BIT(1)
28
29struct sunxi_sid_cfg {
30 u32 value_offset;
31 u32 size;
32 bool need_register_readout;
33};
34
35struct sunxi_sid {
36 void __iomem *base;
37 u32 value_offset;
38};
39
40static int sunxi_sid_read(void *context, unsigned int offset,
41 void *val, size_t bytes)
42{
43 struct sunxi_sid *sid = context;
44
45 memcpy_fromio(val, sid->base + sid->value_offset + offset, bytes);
46
47 return 0;
48}
49
50static int sun8i_sid_register_readout(const struct sunxi_sid *sid,
51 const unsigned int offset,
52 u32 *out)
53{
54 u32 reg_val;
55 int ret;
56
57
58 reg_val = (offset & SUN8I_SID_OFFSET_MASK)
59 << SUN8I_SID_OFFSET_SHIFT;
60 reg_val |= SUN8I_SID_OP_LOCK | SUN8I_SID_READ;
61 writel(reg_val, sid->base + SUN8I_SID_PRCTL);
62
63 ret = readl_poll_timeout(sid->base + SUN8I_SID_PRCTL, reg_val,
64 !(reg_val & SUN8I_SID_READ), 100, 250000);
65 if (ret)
66 return ret;
67
68 if (out)
69 *out = readl(sid->base + SUN8I_SID_RDKEY);
70
71 writel(0, sid->base + SUN8I_SID_PRCTL);
72
73 return 0;
74}
75
76
77
78
79
80
81static int sun8i_sid_read_by_reg(void *context, unsigned int offset,
82 void *val, size_t bytes)
83{
84 struct sunxi_sid *sid = context;
85 u32 word;
86 int ret;
87
88
89 while (bytes >= 4) {
90 ret = sun8i_sid_register_readout(sid, offset, val);
91 if (ret)
92 return ret;
93
94 val += 4;
95 offset += 4;
96 bytes -= 4;
97 }
98
99 if (!bytes)
100 return 0;
101
102
103 ret = sun8i_sid_register_readout(sid, offset, &word);
104 if (ret)
105 return ret;
106
107 memcpy(val, &word, bytes);
108
109 return 0;
110}
111
112static int sunxi_sid_probe(struct platform_device *pdev)
113{
114 struct device *dev = &pdev->dev;
115 struct resource *res;
116 struct nvmem_config *nvmem_cfg;
117 struct nvmem_device *nvmem;
118 struct sunxi_sid *sid;
119 int size;
120 char *randomness;
121 const struct sunxi_sid_cfg *cfg;
122
123 sid = devm_kzalloc(dev, sizeof(*sid), GFP_KERNEL);
124 if (!sid)
125 return -ENOMEM;
126
127 cfg = of_device_get_match_data(dev);
128 if (!cfg)
129 return -EINVAL;
130 sid->value_offset = cfg->value_offset;
131
132 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
133 sid->base = devm_ioremap_resource(dev, res);
134 if (IS_ERR(sid->base))
135 return PTR_ERR(sid->base);
136
137 size = cfg->size;
138
139 nvmem_cfg = devm_kzalloc(dev, sizeof(*nvmem_cfg), GFP_KERNEL);
140 if (!nvmem_cfg)
141 return -ENOMEM;
142
143 nvmem_cfg->dev = dev;
144 nvmem_cfg->name = "sunxi-sid";
145 nvmem_cfg->read_only = true;
146 nvmem_cfg->size = cfg->size;
147 nvmem_cfg->word_size = 1;
148 nvmem_cfg->stride = 4;
149 nvmem_cfg->priv = sid;
150 if (cfg->need_register_readout)
151 nvmem_cfg->reg_read = sun8i_sid_read_by_reg;
152 else
153 nvmem_cfg->reg_read = sunxi_sid_read;
154
155 nvmem = devm_nvmem_register(dev, nvmem_cfg);
156 if (IS_ERR(nvmem))
157 return PTR_ERR(nvmem);
158
159 randomness = kzalloc(size, GFP_KERNEL);
160 if (!randomness)
161 return -ENOMEM;
162
163 nvmem_cfg->reg_read(sid, 0, randomness, size);
164 add_device_randomness(randomness, size);
165 kfree(randomness);
166
167 platform_set_drvdata(pdev, nvmem);
168
169 return 0;
170}
171
172static const struct sunxi_sid_cfg sun4i_a10_cfg = {
173 .size = 0x10,
174};
175
176static const struct sunxi_sid_cfg sun7i_a20_cfg = {
177 .size = 0x200,
178};
179
180static const struct sunxi_sid_cfg sun8i_h3_cfg = {
181 .value_offset = 0x200,
182 .size = 0x100,
183 .need_register_readout = true,
184};
185
186static const struct sunxi_sid_cfg sun50i_a64_cfg = {
187 .value_offset = 0x200,
188 .size = 0x100,
189 .need_register_readout = true,
190};
191
192static const struct sunxi_sid_cfg sun50i_h6_cfg = {
193 .value_offset = 0x200,
194 .size = 0x200,
195};
196
197static const struct of_device_id sunxi_sid_of_match[] = {
198 { .compatible = "allwinner,sun4i-a10-sid", .data = &sun4i_a10_cfg },
199 { .compatible = "allwinner,sun7i-a20-sid", .data = &sun7i_a20_cfg },
200 { .compatible = "allwinner,sun8i-a83t-sid", .data = &sun50i_a64_cfg },
201 { .compatible = "allwinner,sun8i-h3-sid", .data = &sun8i_h3_cfg },
202 { .compatible = "allwinner,sun50i-a64-sid", .data = &sun50i_a64_cfg },
203 { .compatible = "allwinner,sun50i-h5-sid", .data = &sun50i_a64_cfg },
204 { .compatible = "allwinner,sun50i-h6-sid", .data = &sun50i_h6_cfg },
205 {},
206};
207MODULE_DEVICE_TABLE(of, sunxi_sid_of_match);
208
209static struct platform_driver sunxi_sid_driver = {
210 .probe = sunxi_sid_probe,
211 .driver = {
212 .name = "eeprom-sunxi-sid",
213 .of_match_table = sunxi_sid_of_match,
214 },
215};
216module_platform_driver(sunxi_sid_driver);
217
218MODULE_AUTHOR("Oliver Schinagl <oliver@schinagl.nl>");
219MODULE_DESCRIPTION("Allwinner sunxi security id driver");
220MODULE_LICENSE("GPL");
221
