1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2021 Rafał Miłecki <rafal@milecki.pl>
4 */
5
6#include <linux/bcm47xx_nvram.h>
7#include <linux/etherdevice.h>
8#include <linux/if_ether.h>
9#include <linux/io.h>
10#include <linux/mod_devicetable.h>
11#include <linux/module.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
18#define NVRAM_MAGIC "FLSH"
19
20struct brcm_nvram {
21 struct device *dev;
22 void __iomem *base;
23 struct nvmem_cell_info *cells;
24 int ncells;
25};
26
27struct brcm_nvram_header {
28 char magic[4];
29 __le32 len;
30 __le32 crc_ver_init; /* 0:7 crc, 8:15 ver, 16:31 sdram_init */
31 __le32 config_refresh; /* 0:15 sdram_config, 16:31 sdram_refresh */
32 __le32 config_ncdl; /* ncdl values for memc */
33};
34
35static int brcm_nvram_read(void *context, unsigned int offset, void *val,
36 size_t bytes)
37{
38 struct brcm_nvram *priv = context;
39 u8 *dst = val;
40
41 while (bytes--)
42 *dst++ = readb(addr: priv->base + offset++);
43
44 return 0;
45}
46
47static int brcm_nvram_read_post_process_macaddr(void *context, const char *id, int index,
48 unsigned int offset, void *buf, size_t bytes)
49{
50 u8 mac[ETH_ALEN];
51
52 if (bytes != 3 * ETH_ALEN - 1)
53 return -EINVAL;
54
55 if (!mac_pton(s: buf, mac))
56 return -EINVAL;
57
58 if (index)
59 eth_addr_add(addr: mac, offset: index);
60
61 ether_addr_copy(dst: buf, src: mac);
62
63 return 0;
64}
65
66static int brcm_nvram_add_cells(struct brcm_nvram *priv, uint8_t *data,
67 size_t len)
68{
69 struct device *dev = priv->dev;
70 char *var, *value, *eq;
71 int idx;
72
73 priv->ncells = 0;
74 for (var = data + sizeof(struct brcm_nvram_header);
75 var < (char *)data + len && *var;
76 var += strlen(var) + 1) {
77 priv->ncells++;
78 }
79
80 priv->cells = devm_kcalloc(dev, n: priv->ncells, size: sizeof(*priv->cells), GFP_KERNEL);
81 if (!priv->cells)
82 return -ENOMEM;
83
84 for (var = data + sizeof(struct brcm_nvram_header), idx = 0;
85 var < (char *)data + len && *var;
86 var = value + strlen(value) + 1, idx++) {
87 eq = strchr(var, '=');
88 if (!eq)
89 break;
90 *eq = '\0';
91 value = eq + 1;
92
93 priv->cells[idx].name = devm_kstrdup(dev, s: var, GFP_KERNEL);
94 if (!priv->cells[idx].name)
95 return -ENOMEM;
96 priv->cells[idx].offset = value - (char *)data;
97 priv->cells[idx].bytes = strlen(value);
98 priv->cells[idx].np = of_get_child_by_name(node: dev->of_node, name: priv->cells[idx].name);
99 if (!strcmp(var, "et0macaddr") ||
100 !strcmp(var, "et1macaddr") ||
101 !strcmp(var, "et2macaddr")) {
102 priv->cells[idx].raw_len = strlen(value);
103 priv->cells[idx].bytes = ETH_ALEN;
104 priv->cells[idx].read_post_process = brcm_nvram_read_post_process_macaddr;
105 }
106 }
107
108 return 0;
109}
110
111static int brcm_nvram_parse(struct brcm_nvram *priv)
112{
113 struct device *dev = priv->dev;
114 struct brcm_nvram_header header;
115 uint8_t *data;
116 size_t len;
117 int err;
118
119 memcpy_fromio(&header, priv->base, sizeof(header));
120
121 if (memcmp(p: header.magic, NVRAM_MAGIC, size: 4)) {
122 dev_err(dev, "Invalid NVRAM magic\n");
123 return -EINVAL;
124 }
125
126 len = le32_to_cpu(header.len);
127
128 data = kzalloc(size: len, GFP_KERNEL);
129 if (!data)
130 return -ENOMEM;
131
132 memcpy_fromio(data, priv->base, len);
133 data[len - 1] = '\0';
134
135 err = brcm_nvram_add_cells(priv, data, len);
136 if (err) {
137 dev_err(dev, "Failed to add cells: %d\n", err);
138 return err;
139 }
140
141 kfree(objp: data);
142
143 return 0;
144}
145
146static int brcm_nvram_probe(struct platform_device *pdev)
147{
148 struct nvmem_config config = {
149 .name = "brcm-nvram",
150 .reg_read = brcm_nvram_read,
151 };
152 struct device *dev = &pdev->dev;
153 struct resource *res;
154 struct brcm_nvram *priv;
155 int err;
156
157 priv = devm_kzalloc(dev, size: sizeof(*priv), GFP_KERNEL);
158 if (!priv)
159 return -ENOMEM;
160 priv->dev = dev;
161
162 priv->base = devm_platform_get_and_ioremap_resource(pdev, index: 0, res: &res);
163 if (IS_ERR(ptr: priv->base))
164 return PTR_ERR(ptr: priv->base);
165
166 err = brcm_nvram_parse(priv);
167 if (err)
168 return err;
169
170 bcm47xx_nvram_init_from_iomem(nvram_start: priv->base, res_size: resource_size(res));
171
172 config.dev = dev;
173 config.cells = priv->cells;
174 config.ncells = priv->ncells;
175 config.priv = priv;
176 config.size = resource_size(res);
177
178 return PTR_ERR_OR_ZERO(ptr: devm_nvmem_register(dev, cfg: &config));
179}
180
181static const struct of_device_id brcm_nvram_of_match_table[] = {
182 { .compatible = "brcm,nvram", },
183 {},
184};
185
186static struct platform_driver brcm_nvram_driver = {
187 .probe = brcm_nvram_probe,
188 .driver = {
189 .name = "brcm_nvram",
190 .of_match_table = brcm_nvram_of_match_table,
191 },
192};
193
194static int __init brcm_nvram_init(void)
195{
196 return platform_driver_register(&brcm_nvram_driver);
197}
198
199subsys_initcall_sync(brcm_nvram_init);
200
201MODULE_AUTHOR("Rafał Miłecki");
202MODULE_LICENSE("GPL");
203MODULE_DEVICE_TABLE(of, brcm_nvram_of_match_table);
204

source code of linux/drivers/nvmem/brcm_nvram.c