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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Allwinner sunXi SoCs Security ID support.
4 *
5 * Copyright (c) 2013 Oliver Schinagl <oliver@schinagl.nl>
6 * Copyright (C) 2014 Maxime Ripard <maxime.ripard@free-electrons.com>
7 */
8
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/platform_device.h>
16#include <linux/slab.h>
17#include <linux/random.h>
18
19/* Registers and special values for doing register-based SID readout on H3 */
20#define SUN8I_SID_PRCTL 0x40
21#define SUN8I_SID_RDKEY 0x60
22
23#define SUN8I_SID_OFFSET_MASK 0x1FF
24#define SUN8I_SID_OFFSET_SHIFT 16
25#define SUN8I_SID_OP_LOCK (0xAC << 8)
26#define SUN8I_SID_READ BIT(1)
27
28struct sunxi_sid_cfg {
29 u32 value_offset;
30 u32 size;
31 bool need_register_readout;
32};
33
34struct sunxi_sid {
35 void __iomem *base;
36 u32 value_offset;
37};
38
39static int sunxi_sid_read(void *context, unsigned int offset,
40 void *val, size_t bytes)
41{
42 struct sunxi_sid *sid = context;
43 u32 word;
44
45 /* .stride = 4 so offset is guaranteed to be aligned */
46 __ioread32_copy(val, sid->base + sid->value_offset + offset, bytes / 4);
47
48 val += round_down(bytes, 4);
49 offset += round_down(bytes, 4);
50 bytes = bytes % 4;
51
52 if (!bytes)
53 return 0;
54
55 /* Handle any trailing bytes */
56 word = readl_relaxed(sid->base + sid->value_offset + offset);
57 memcpy(val, &word, bytes);
58
59 return 0;
60}
61
62static int sun8i_sid_register_readout(const struct sunxi_sid *sid,
63 const unsigned int offset,
64 u32 *out)
65{
66 u32 reg_val;
67 int ret;
68
69 /* Set word, lock access, and set read command */
70 reg_val = (offset & SUN8I_SID_OFFSET_MASK)
71 << SUN8I_SID_OFFSET_SHIFT;
72 reg_val |= SUN8I_SID_OP_LOCK | SUN8I_SID_READ;
73 writel(reg_val, sid->base + SUN8I_SID_PRCTL);
74
75 ret = readl_poll_timeout(sid->base + SUN8I_SID_PRCTL, reg_val,
76 !(reg_val & SUN8I_SID_READ), 100, 250000);
77 if (ret)
78 return ret;
79
80 if (out)
81 *out = readl(sid->base + SUN8I_SID_RDKEY);
82
83 writel(0, sid->base + SUN8I_SID_PRCTL);
84
85 return 0;
86}
87
88/*
89 * On Allwinner H3, the value on the 0x200 offset of the SID controller seems
90 * to be not reliable at all.
91 * Read by the registers instead.
92 */
93static int sun8i_sid_read_by_reg(void *context, unsigned int offset,
94 void *val, size_t bytes)
95{
96 struct sunxi_sid *sid = context;
97 u32 word;
98 int ret;
99
100 /* .stride = 4 so offset is guaranteed to be aligned */
101 while (bytes >= 4) {
102 ret = sun8i_sid_register_readout(sid, offset, val);
103 if (ret)
104 return ret;
105
106 val += 4;
107 offset += 4;
108 bytes -= 4;
109 }
110
111 if (!bytes)
112 return 0;
113
114 /* Handle any trailing bytes */
115 ret = sun8i_sid_register_readout(sid, offset, &word);
116 if (ret)
117 return ret;
118
119 memcpy(val, &word, bytes);
120
121 return 0;
122}
123
124static int sunxi_sid_probe(struct platform_device *pdev)
125{
126 struct device *dev = &pdev->dev;
127 struct nvmem_config *nvmem_cfg;
128 struct nvmem_device *nvmem;
129 struct sunxi_sid *sid;
130 int size;
131 char *randomness;
132 const struct sunxi_sid_cfg *cfg;
133
134 sid = devm_kzalloc(dev, sizeof(*sid), GFP_KERNEL);
135 if (!sid)
136 return -ENOMEM;
137
138 cfg = of_device_get_match_data(dev);
139 if (!cfg)
140 return -EINVAL;
141 sid->value_offset = cfg->value_offset;
142
143 sid->base = devm_platform_ioremap_resource(pdev, 0);
144 if (IS_ERR(sid->base))
145 return PTR_ERR(sid->base);
146
147 size = cfg->size;
148
149 nvmem_cfg = devm_kzalloc(dev, sizeof(*nvmem_cfg), GFP_KERNEL);
150 if (!nvmem_cfg)
151 return -ENOMEM;
152
153 nvmem_cfg->dev = dev;
154 nvmem_cfg->name = "sunxi-sid";
155 nvmem_cfg->type = NVMEM_TYPE_OTP;
156 nvmem_cfg->add_legacy_fixed_of_cells = true;
157 nvmem_cfg->read_only = true;
158 nvmem_cfg->size = cfg->size;
159 nvmem_cfg->word_size = 1;
160 nvmem_cfg->stride = 4;
161 nvmem_cfg->priv = sid;
162 if (cfg->need_register_readout)
163 nvmem_cfg->reg_read = sun8i_sid_read_by_reg;
164 else
165 nvmem_cfg->reg_read = sunxi_sid_read;
166
167 nvmem = devm_nvmem_register(dev, nvmem_cfg);
168 if (IS_ERR(nvmem))
169 return PTR_ERR(nvmem);
170
171 randomness = kzalloc(size, GFP_KERNEL);
172 if (!randomness)
173 return -ENOMEM;
174
175 nvmem_cfg->reg_read(sid, 0, randomness, size);
176 add_device_randomness(randomness, size);
177 kfree(randomness);
178
179 platform_set_drvdata(pdev, nvmem);
180
181 return 0;
182}
183
184static const struct sunxi_sid_cfg sun4i_a10_cfg = {
185 .size = 0x10,
186};
187
188static const struct sunxi_sid_cfg sun7i_a20_cfg = {
189 .size = 0x200,
190};
191
192static const struct sunxi_sid_cfg sun8i_h3_cfg = {
193 .value_offset = 0x200,
194 .size = 0x100,
195 .need_register_readout = true,
196};
197
198static const struct sunxi_sid_cfg sun50i_a64_cfg = {
199 .value_offset = 0x200,
200 .size = 0x100,
201};
202
203static const struct sunxi_sid_cfg sun50i_h6_cfg = {
204 .value_offset = 0x200,
205 .size = 0x200,
206};
207
208static const struct of_device_id sunxi_sid_of_match[] = {
209 { .compatible = "allwinner,sun4i-a10-sid", .data = &sun4i_a10_cfg },
210 { .compatible = "allwinner,sun7i-a20-sid", .data = &sun7i_a20_cfg },
211 { .compatible = "allwinner,sun8i-a83t-sid", .data = &sun50i_a64_cfg },
212 { .compatible = "allwinner,sun8i-h3-sid", .data = &sun8i_h3_cfg },
213 { .compatible = "allwinner,sun20i-d1-sid", .data = &sun50i_a64_cfg },
214 { .compatible = "allwinner,sun50i-a64-sid", .data = &sun50i_a64_cfg },
215 { .compatible = "allwinner,sun50i-h5-sid", .data = &sun50i_a64_cfg },
216 { .compatible = "allwinner,sun50i-h6-sid", .data = &sun50i_h6_cfg },
217 {/* sentinel */},
218};
219MODULE_DEVICE_TABLE(of, sunxi_sid_of_match);
220
221static struct platform_driver sunxi_sid_driver = {
222 .probe = sunxi_sid_probe,
223 .driver = {
224 .name = "eeprom-sunxi-sid",
225 .of_match_table = sunxi_sid_of_match,
226 },
227};
228module_platform_driver(sunxi_sid_driver);
229
230MODULE_AUTHOR("Oliver Schinagl <oliver@schinagl.nl>");
231MODULE_DESCRIPTION("Allwinner sunxi security id driver");
232MODULE_LICENSE("GPL");
1/*
2 * Allwinner sunXi SoCs Security ID support.
3 *
4 * Copyright (c) 2013 Oliver Schinagl <oliver@schinagl.nl>
5 * Copyright (C) 2014 Maxime Ripard <maxime.ripard@free-electrons.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 */
17
18#include <linux/device.h>
19#include <linux/io.h>
20#include <linux/iopoll.h>
21#include <linux/module.h>
22#include <linux/nvmem-provider.h>
23#include <linux/of.h>
24#include <linux/of_device.h>
25#include <linux/platform_device.h>
26#include <linux/slab.h>
27#include <linux/random.h>
28
29/* Registers and special values for doing register-based SID readout on H3 */
30#define SUN8I_SID_PRCTL 0x40
31#define SUN8I_SID_RDKEY 0x60
32
33#define SUN8I_SID_OFFSET_MASK 0x1FF
34#define SUN8I_SID_OFFSET_SHIFT 16
35#define SUN8I_SID_OP_LOCK (0xAC << 8)
36#define SUN8I_SID_READ BIT(1)
37
38static struct nvmem_config econfig = {
39 .name = "sunxi-sid",
40 .read_only = true,
41 .stride = 4,
42 .word_size = 1,
43};
44
45struct sunxi_sid_cfg {
46 u32 value_offset;
47 u32 size;
48 bool need_register_readout;
49};
50
51struct sunxi_sid {
52 void __iomem *base;
53 u32 value_offset;
54};
55
56/* We read the entire key, due to a 32 bit read alignment requirement. Since we
57 * want to return the requested byte, this results in somewhat slower code and
58 * uses 4 times more reads as needed but keeps code simpler. Since the SID is
59 * only very rarely probed, this is not really an issue.
60 */
61static u8 sunxi_sid_read_byte(const struct sunxi_sid *sid,
62 const unsigned int offset)
63{
64 u32 sid_key;
65
66 sid_key = ioread32be(sid->base + round_down(offset, 4));
67 sid_key >>= (offset % 4) * 8;
68
69 return sid_key; /* Only return the last byte */
70}
71
72static int sunxi_sid_read(void *context, unsigned int offset,
73 void *val, size_t bytes)
74{
75 struct sunxi_sid *sid = context;
76 u8 *buf = val;
77
78 /* Offset the read operation to the real position of SID */
79 offset += sid->value_offset;
80
81 while (bytes--)
82 *buf++ = sunxi_sid_read_byte(sid, offset++);
83
84 return 0;
85}
86
87static int sun8i_sid_register_readout(const struct sunxi_sid *sid,
88 const unsigned int offset,
89 u32 *out)
90{
91 u32 reg_val;
92 int ret;
93
94 /* Set word, lock access, and set read command */
95 reg_val = (offset & SUN8I_SID_OFFSET_MASK)
96 << SUN8I_SID_OFFSET_SHIFT;
97 reg_val |= SUN8I_SID_OP_LOCK | SUN8I_SID_READ;
98 writel(reg_val, sid->base + SUN8I_SID_PRCTL);
99
100 ret = readl_poll_timeout(sid->base + SUN8I_SID_PRCTL, reg_val,
101 !(reg_val & SUN8I_SID_READ), 100, 250000);
102 if (ret)
103 return ret;
104
105 if (out)
106 *out = readl(sid->base + SUN8I_SID_RDKEY);
107
108 writel(0, sid->base + SUN8I_SID_PRCTL);
109
110 return 0;
111}
112
113/*
114 * On Allwinner H3, the value on the 0x200 offset of the SID controller seems
115 * to be not reliable at all.
116 * Read by the registers instead.
117 */
118static int sun8i_sid_read_byte_by_reg(const struct sunxi_sid *sid,
119 const unsigned int offset,
120 u8 *out)
121{
122 u32 word;
123 int ret;
124
125 ret = sun8i_sid_register_readout(sid, offset & ~0x03, &word);
126
127 if (ret)
128 return ret;
129
130 *out = (word >> ((offset & 0x3) * 8)) & 0xff;
131
132 return 0;
133}
134
135static int sun8i_sid_read_by_reg(void *context, unsigned int offset,
136 void *val, size_t bytes)
137{
138 struct sunxi_sid *sid = context;
139 u8 *buf = val;
140 int ret;
141
142 while (bytes--) {
143 ret = sun8i_sid_read_byte_by_reg(sid, offset++, buf++);
144 if (ret)
145 return ret;
146 }
147
148 return 0;
149}
150
151static int sunxi_sid_probe(struct platform_device *pdev)
152{
153 struct device *dev = &pdev->dev;
154 struct resource *res;
155 struct nvmem_device *nvmem;
156 struct sunxi_sid *sid;
157 int ret, i, size;
158 char *randomness;
159 const struct sunxi_sid_cfg *cfg;
160
161 sid = devm_kzalloc(dev, sizeof(*sid), GFP_KERNEL);
162 if (!sid)
163 return -ENOMEM;
164
165 cfg = of_device_get_match_data(dev);
166 if (!cfg)
167 return -EINVAL;
168 sid->value_offset = cfg->value_offset;
169
170 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
171 sid->base = devm_ioremap_resource(dev, res);
172 if (IS_ERR(sid->base))
173 return PTR_ERR(sid->base);
174
175 size = cfg->size;
176
177 econfig.size = size;
178 econfig.dev = dev;
179 if (cfg->need_register_readout)
180 econfig.reg_read = sun8i_sid_read_by_reg;
181 else
182 econfig.reg_read = sunxi_sid_read;
183 econfig.priv = sid;
184 nvmem = nvmem_register(&econfig);
185 if (IS_ERR(nvmem))
186 return PTR_ERR(nvmem);
187
188 randomness = kzalloc(sizeof(u8) * (size), GFP_KERNEL);
189 if (!randomness) {
190 ret = -EINVAL;
191 goto err_unreg_nvmem;
192 }
193
194 for (i = 0; i < size; i++)
195 econfig.reg_read(sid, i, &randomness[i], 1);
196
197 add_device_randomness(randomness, size);
198 kfree(randomness);
199
200 platform_set_drvdata(pdev, nvmem);
201
202 return 0;
203
204err_unreg_nvmem:
205 nvmem_unregister(nvmem);
206 return ret;
207}
208
209static int sunxi_sid_remove(struct platform_device *pdev)
210{
211 struct nvmem_device *nvmem = platform_get_drvdata(pdev);
212
213 return nvmem_unregister(nvmem);
214}
215
216static const struct sunxi_sid_cfg sun4i_a10_cfg = {
217 .size = 0x10,
218};
219
220static const struct sunxi_sid_cfg sun7i_a20_cfg = {
221 .size = 0x200,
222};
223
224static const struct sunxi_sid_cfg sun8i_h3_cfg = {
225 .value_offset = 0x200,
226 .size = 0x100,
227 .need_register_readout = true,
228};
229
230static const struct sunxi_sid_cfg sun50i_a64_cfg = {
231 .value_offset = 0x200,
232 .size = 0x100,
233};
234
235static const struct of_device_id sunxi_sid_of_match[] = {
236 { .compatible = "allwinner,sun4i-a10-sid", .data = &sun4i_a10_cfg },
237 { .compatible = "allwinner,sun7i-a20-sid", .data = &sun7i_a20_cfg },
238 { .compatible = "allwinner,sun8i-h3-sid", .data = &sun8i_h3_cfg },
239 { .compatible = "allwinner,sun50i-a64-sid", .data = &sun50i_a64_cfg },
240 {/* sentinel */},
241};
242MODULE_DEVICE_TABLE(of, sunxi_sid_of_match);
243
244static struct platform_driver sunxi_sid_driver = {
245 .probe = sunxi_sid_probe,
246 .remove = sunxi_sid_remove,
247 .driver = {
248 .name = "eeprom-sunxi-sid",
249 .of_match_table = sunxi_sid_of_match,
250 },
251};
252module_platform_driver(sunxi_sid_driver);
253
254MODULE_AUTHOR("Oliver Schinagl <oliver@schinagl.nl>");
255MODULE_DESCRIPTION("Allwinner sunxi security id driver");
256MODULE_LICENSE("GPL");