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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2022 Rafał Miłecki <rafal@milecki.pl>
4 */
5
6#include <linux/crc32.h>
7#include <linux/mod_devicetable.h>
8#include <linux/module.h>
9#include <linux/mtd/mtd.h>
10#include <linux/nvmem-consumer.h>
11#include <linux/nvmem-provider.h>
12#include <linux/of_device.h>
13#include <linux/platform_device.h>
14#include <linux/slab.h>
15
16enum u_boot_env_format {
17 U_BOOT_FORMAT_SINGLE,
18 U_BOOT_FORMAT_REDUNDANT,
19 U_BOOT_FORMAT_BROADCOM,
20};
21
22struct u_boot_env {
23 struct device *dev;
24 enum u_boot_env_format format;
25
26 struct mtd_info *mtd;
27
28 /* Cells */
29 struct nvmem_cell_info *cells;
30 int ncells;
31};
32
33struct u_boot_env_image_single {
34 __le32 crc32;
35 uint8_t data[];
36} __packed;
37
38struct u_boot_env_image_redundant {
39 __le32 crc32;
40 u8 mark;
41 uint8_t data[];
42} __packed;
43
44struct u_boot_env_image_broadcom {
45 __le32 magic;
46 __le32 len;
47 __le32 crc32;
48 uint8_t data[0];
49} __packed;
50
51static int u_boot_env_read(void *context, unsigned int offset, void *val,
52 size_t bytes)
53{
54 struct u_boot_env *priv = context;
55 struct device *dev = priv->dev;
56 size_t bytes_read;
57 int err;
58
59 err = mtd_read(priv->mtd, offset, bytes, &bytes_read, val);
60 if (err && !mtd_is_bitflip(err)) {
61 dev_err(dev, "Failed to read from mtd: %d\n", err);
62 return err;
63 }
64
65 if (bytes_read != bytes) {
66 dev_err(dev, "Failed to read %zu bytes\n", bytes);
67 return -EIO;
68 }
69
70 return 0;
71}
72
73static int u_boot_env_add_cells(struct u_boot_env *priv, uint8_t *buf,
74 size_t data_offset, size_t data_len)
75{
76 struct device *dev = priv->dev;
77 char *data = buf + data_offset;
78 char *var, *value, *eq;
79 int idx;
80
81 priv->ncells = 0;
82 for (var = data; var < data + data_len && *var; var += strlen(var) + 1)
83 priv->ncells++;
84
85 priv->cells = devm_kcalloc(dev, priv->ncells, sizeof(*priv->cells), GFP_KERNEL);
86 if (!priv->cells)
87 return -ENOMEM;
88
89 for (var = data, idx = 0;
90 var < data + data_len && *var;
91 var = value + strlen(value) + 1, idx++) {
92 eq = strchr(var, '=');
93 if (!eq)
94 break;
95 *eq = '\0';
96 value = eq + 1;
97
98 priv->cells[idx].name = devm_kstrdup(dev, var, GFP_KERNEL);
99 if (!priv->cells[idx].name)
100 return -ENOMEM;
101 priv->cells[idx].offset = data_offset + value - data;
102 priv->cells[idx].bytes = strlen(value);
103 priv->cells[idx].np = of_get_child_by_name(dev->of_node, priv->cells[idx].name);
104 }
105
106 if (WARN_ON(idx != priv->ncells))
107 priv->ncells = idx;
108
109 return 0;
110}
111
112static int u_boot_env_parse(struct u_boot_env *priv)
113{
114 struct device *dev = priv->dev;
115 size_t crc32_data_offset;
116 size_t crc32_data_len;
117 size_t crc32_offset;
118 size_t data_offset;
119 size_t data_len;
120 uint32_t crc32;
121 uint32_t calc;
122 size_t bytes;
123 uint8_t *buf;
124 int err;
125
126 buf = kcalloc(1, priv->mtd->size, GFP_KERNEL);
127 if (!buf) {
128 err = -ENOMEM;
129 goto err_out;
130 }
131
132 err = mtd_read(priv->mtd, 0, priv->mtd->size, &bytes, buf);
133 if ((err && !mtd_is_bitflip(err)) || bytes != priv->mtd->size) {
134 dev_err(dev, "Failed to read from mtd: %d\n", err);
135 goto err_kfree;
136 }
137
138 switch (priv->format) {
139 case U_BOOT_FORMAT_SINGLE:
140 crc32_offset = offsetof(struct u_boot_env_image_single, crc32);
141 crc32_data_offset = offsetof(struct u_boot_env_image_single, data);
142 data_offset = offsetof(struct u_boot_env_image_single, data);
143 break;
144 case U_BOOT_FORMAT_REDUNDANT:
145 crc32_offset = offsetof(struct u_boot_env_image_redundant, crc32);
146 crc32_data_offset = offsetof(struct u_boot_env_image_redundant, data);
147 data_offset = offsetof(struct u_boot_env_image_redundant, data);
148 break;
149 case U_BOOT_FORMAT_BROADCOM:
150 crc32_offset = offsetof(struct u_boot_env_image_broadcom, crc32);
151 crc32_data_offset = offsetof(struct u_boot_env_image_broadcom, data);
152 data_offset = offsetof(struct u_boot_env_image_broadcom, data);
153 break;
154 }
155 crc32 = le32_to_cpu(*(__le32 *)(buf + crc32_offset));
156 crc32_data_len = priv->mtd->size - crc32_data_offset;
157 data_len = priv->mtd->size - data_offset;
158
159 calc = crc32(~0, buf + crc32_data_offset, crc32_data_len) ^ ~0L;
160 if (calc != crc32) {
161 dev_err(dev, "Invalid calculated CRC32: 0x%08x (expected: 0x%08x)\n", calc, crc32);
162 err = -EINVAL;
163 goto err_kfree;
164 }
165
166 buf[priv->mtd->size - 1] = '\0';
167 err = u_boot_env_add_cells(priv, buf, data_offset, data_len);
168 if (err)
169 dev_err(dev, "Failed to add cells: %d\n", err);
170
171err_kfree:
172 kfree(buf);
173err_out:
174 return err;
175}
176
177static int u_boot_env_probe(struct platform_device *pdev)
178{
179 struct nvmem_config config = {
180 .name = "u-boot-env",
181 .reg_read = u_boot_env_read,
182 };
183 struct device *dev = &pdev->dev;
184 struct device_node *np = dev->of_node;
185 struct u_boot_env *priv;
186 int err;
187
188 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
189 if (!priv)
190 return -ENOMEM;
191 priv->dev = dev;
192
193 priv->format = (uintptr_t)of_device_get_match_data(dev);
194
195 priv->mtd = of_get_mtd_device_by_node(np);
196 if (IS_ERR(priv->mtd)) {
197 dev_err_probe(dev, PTR_ERR(priv->mtd), "Failed to get %pOF MTD\n", np);
198 return PTR_ERR(priv->mtd);
199 }
200
201 err = u_boot_env_parse(priv);
202 if (err)
203 return err;
204
205 config.dev = dev;
206 config.cells = priv->cells;
207 config.ncells = priv->ncells;
208 config.priv = priv;
209 config.size = priv->mtd->size;
210
211 return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &config));
212}
213
214static const struct of_device_id u_boot_env_of_match_table[] = {
215 { .compatible = "u-boot,env", .data = (void *)U_BOOT_FORMAT_SINGLE, },
216 { .compatible = "u-boot,env-redundant-bool", .data = (void *)U_BOOT_FORMAT_REDUNDANT, },
217 { .compatible = "u-boot,env-redundant-count", .data = (void *)U_BOOT_FORMAT_REDUNDANT, },
218 { .compatible = "brcm,env", .data = (void *)U_BOOT_FORMAT_BROADCOM, },
219 {},
220};
221
222static struct platform_driver u_boot_env_driver = {
223 .probe = u_boot_env_probe,
224 .driver = {
225 .name = "u_boot_env",
226 .of_match_table = u_boot_env_of_match_table,
227 },
228};
229module_platform_driver(u_boot_env_driver);
230
231MODULE_AUTHOR("Rafał Miłecki");
232MODULE_LICENSE("GPL");
233MODULE_DEVICE_TABLE(of, u_boot_env_of_match_table);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2022 Rafał Miłecki <rafal@milecki.pl>
4 */
5
6#include <linux/crc32.h>
7#include <linux/etherdevice.h>
8#include <linux/if_ether.h>
9#include <linux/mod_devicetable.h>
10#include <linux/module.h>
11#include <linux/mtd/mtd.h>
12#include <linux/nvmem-consumer.h>
13#include <linux/nvmem-provider.h>
14#include <linux/of.h>
15#include <linux/platform_device.h>
16#include <linux/slab.h>
17
18enum u_boot_env_format {
19 U_BOOT_FORMAT_SINGLE,
20 U_BOOT_FORMAT_REDUNDANT,
21 U_BOOT_FORMAT_BROADCOM,
22};
23
24struct u_boot_env {
25 struct device *dev;
26 struct nvmem_device *nvmem;
27 enum u_boot_env_format format;
28
29 struct mtd_info *mtd;
30};
31
32struct u_boot_env_image_single {
33 __le32 crc32;
34 uint8_t data[];
35} __packed;
36
37struct u_boot_env_image_redundant {
38 __le32 crc32;
39 u8 mark;
40 uint8_t data[];
41} __packed;
42
43struct u_boot_env_image_broadcom {
44 __le32 magic;
45 __le32 len;
46 __le32 crc32;
47 DECLARE_FLEX_ARRAY(uint8_t, data);
48} __packed;
49
50static int u_boot_env_read(void *context, unsigned int offset, void *val,
51 size_t bytes)
52{
53 struct u_boot_env *priv = context;
54 struct device *dev = priv->dev;
55 size_t bytes_read;
56 int err;
57
58 err = mtd_read(priv->mtd, offset, bytes, &bytes_read, val);
59 if (err && !mtd_is_bitflip(err)) {
60 dev_err(dev, "Failed to read from mtd: %d\n", err);
61 return err;
62 }
63
64 if (bytes_read != bytes) {
65 dev_err(dev, "Failed to read %zu bytes\n", bytes);
66 return -EIO;
67 }
68
69 return 0;
70}
71
72static int u_boot_env_read_post_process_ethaddr(void *context, const char *id, int index,
73 unsigned int offset, void *buf, size_t bytes)
74{
75 u8 mac[ETH_ALEN];
76
77 if (bytes != 3 * ETH_ALEN - 1)
78 return -EINVAL;
79
80 if (!mac_pton(buf, mac))
81 return -EINVAL;
82
83 if (index)
84 eth_addr_add(mac, index);
85
86 ether_addr_copy(buf, mac);
87
88 return 0;
89}
90
91static int u_boot_env_add_cells(struct u_boot_env *priv, uint8_t *buf,
92 size_t data_offset, size_t data_len)
93{
94 struct nvmem_device *nvmem = priv->nvmem;
95 struct device *dev = priv->dev;
96 char *data = buf + data_offset;
97 char *var, *value, *eq;
98
99 for (var = data;
100 var < data + data_len && *var;
101 var = value + strlen(value) + 1) {
102 struct nvmem_cell_info info = {};
103
104 eq = strchr(var, '=');
105 if (!eq)
106 break;
107 *eq = '\0';
108 value = eq + 1;
109
110 info.name = devm_kstrdup(dev, var, GFP_KERNEL);
111 if (!info.name)
112 return -ENOMEM;
113 info.offset = data_offset + value - data;
114 info.bytes = strlen(value);
115 info.np = of_get_child_by_name(dev->of_node, info.name);
116 if (!strcmp(var, "ethaddr")) {
117 info.raw_len = strlen(value);
118 info.bytes = ETH_ALEN;
119 info.read_post_process = u_boot_env_read_post_process_ethaddr;
120 }
121
122 nvmem_add_one_cell(nvmem, &info);
123 }
124
125 return 0;
126}
127
128static int u_boot_env_parse(struct u_boot_env *priv)
129{
130 struct nvmem_device *nvmem = priv->nvmem;
131 struct device *dev = priv->dev;
132 size_t crc32_data_offset;
133 size_t crc32_data_len;
134 size_t crc32_offset;
135 __le32 *crc32_addr;
136 size_t data_offset;
137 size_t data_len;
138 size_t dev_size;
139 uint32_t crc32;
140 uint32_t calc;
141 uint8_t *buf;
142 int bytes;
143 int err;
144
145 dev_size = nvmem_dev_size(nvmem);
146
147 buf = kzalloc(dev_size, GFP_KERNEL);
148 if (!buf) {
149 err = -ENOMEM;
150 goto err_out;
151 }
152
153 bytes = nvmem_device_read(nvmem, 0, dev_size, buf);
154 if (bytes < 0) {
155 err = bytes;
156 goto err_kfree;
157 } else if (bytes != dev_size) {
158 err = -EIO;
159 goto err_kfree;
160 }
161
162 switch (priv->format) {
163 case U_BOOT_FORMAT_SINGLE:
164 crc32_offset = offsetof(struct u_boot_env_image_single, crc32);
165 crc32_data_offset = offsetof(struct u_boot_env_image_single, data);
166 data_offset = offsetof(struct u_boot_env_image_single, data);
167 break;
168 case U_BOOT_FORMAT_REDUNDANT:
169 crc32_offset = offsetof(struct u_boot_env_image_redundant, crc32);
170 crc32_data_offset = offsetof(struct u_boot_env_image_redundant, data);
171 data_offset = offsetof(struct u_boot_env_image_redundant, data);
172 break;
173 case U_BOOT_FORMAT_BROADCOM:
174 crc32_offset = offsetof(struct u_boot_env_image_broadcom, crc32);
175 crc32_data_offset = offsetof(struct u_boot_env_image_broadcom, data);
176 data_offset = offsetof(struct u_boot_env_image_broadcom, data);
177 break;
178 }
179 crc32_addr = (__le32 *)(buf + crc32_offset);
180 crc32 = le32_to_cpu(*crc32_addr);
181 crc32_data_len = dev_size - crc32_data_offset;
182 data_len = dev_size - data_offset;
183
184 calc = crc32(~0, buf + crc32_data_offset, crc32_data_len) ^ ~0L;
185 if (calc != crc32) {
186 dev_err(dev, "Invalid calculated CRC32: 0x%08x (expected: 0x%08x)\n", calc, crc32);
187 err = -EINVAL;
188 goto err_kfree;
189 }
190
191 buf[dev_size - 1] = '\0';
192 err = u_boot_env_add_cells(priv, buf, data_offset, data_len);
193
194err_kfree:
195 kfree(buf);
196err_out:
197 return err;
198}
199
200static int u_boot_env_probe(struct platform_device *pdev)
201{
202 struct nvmem_config config = {
203 .name = "u-boot-env",
204 .reg_read = u_boot_env_read,
205 };
206 struct device *dev = &pdev->dev;
207 struct device_node *np = dev->of_node;
208 struct u_boot_env *priv;
209
210 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
211 if (!priv)
212 return -ENOMEM;
213 priv->dev = dev;
214
215 priv->format = (uintptr_t)of_device_get_match_data(dev);
216
217 priv->mtd = of_get_mtd_device_by_node(np);
218 if (IS_ERR(priv->mtd)) {
219 dev_err_probe(dev, PTR_ERR(priv->mtd), "Failed to get %pOF MTD\n", np);
220 return PTR_ERR(priv->mtd);
221 }
222
223 config.dev = dev;
224 config.priv = priv;
225 config.size = priv->mtd->size;
226
227 priv->nvmem = devm_nvmem_register(dev, &config);
228 if (IS_ERR(priv->nvmem))
229 return PTR_ERR(priv->nvmem);
230
231 return u_boot_env_parse(priv);
232}
233
234static const struct of_device_id u_boot_env_of_match_table[] = {
235 { .compatible = "u-boot,env", .data = (void *)U_BOOT_FORMAT_SINGLE, },
236 { .compatible = "u-boot,env-redundant-bool", .data = (void *)U_BOOT_FORMAT_REDUNDANT, },
237 { .compatible = "u-boot,env-redundant-count", .data = (void *)U_BOOT_FORMAT_REDUNDANT, },
238 { .compatible = "brcm,env", .data = (void *)U_BOOT_FORMAT_BROADCOM, },
239 {},
240};
241
242static struct platform_driver u_boot_env_driver = {
243 .probe = u_boot_env_probe,
244 .driver = {
245 .name = "u_boot_env",
246 .of_match_table = u_boot_env_of_match_table,
247 },
248};
249module_platform_driver(u_boot_env_driver);
250
251MODULE_AUTHOR("Rafał Miłecki");
252MODULE_LICENSE("GPL");
253MODULE_DEVICE_TABLE(of, u_boot_env_of_match_table);