1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2021 Rafał Miłecki <rafal@milecki.pl>
7 #include <linux/mod_devicetable.h>
8 #include <linux/module.h>
9 #include <linux/nvmem-consumer.h>
10 #include <linux/nvmem-provider.h>
11 #include <linux/platform_device.h>
12 #include <linux/slab.h>
14 #define NVRAM_MAGIC "FLSH"
19 struct nvmem_cell_info *cells;
23 struct brcm_nvram_header {
26 __le32 crc_ver_init; /* 0:7 crc, 8:15 ver, 16:31 sdram_init */
27 __le32 config_refresh; /* 0:15 sdram_config, 16:31 sdram_refresh */
28 __le32 config_ncdl; /* ncdl values for memc */
31 static int brcm_nvram_read(void *context, unsigned int offset, void *val,
34 struct brcm_nvram *priv = context;
38 *dst++ = readb(priv->base + offset++);
43 static int brcm_nvram_add_cells(struct brcm_nvram *priv, uint8_t *data,
46 struct device *dev = priv->dev;
47 char *var, *value, *eq;
51 for (var = data + sizeof(struct brcm_nvram_header);
52 var < (char *)data + len && *var;
53 var += strlen(var) + 1) {
57 priv->cells = devm_kcalloc(dev, priv->ncells, sizeof(*priv->cells), GFP_KERNEL);
61 for (var = data + sizeof(struct brcm_nvram_header), idx = 0;
62 var < (char *)data + len && *var;
63 var = value + strlen(value) + 1, idx++) {
64 eq = strchr(var, '=');
70 priv->cells[idx].name = devm_kstrdup(dev, var, GFP_KERNEL);
71 if (!priv->cells[idx].name)
73 priv->cells[idx].offset = value - (char *)data;
74 priv->cells[idx].bytes = strlen(value);
80 static int brcm_nvram_parse(struct brcm_nvram *priv)
82 struct device *dev = priv->dev;
83 struct brcm_nvram_header header;
88 memcpy_fromio(&header, priv->base, sizeof(header));
90 if (memcmp(header.magic, NVRAM_MAGIC, 4)) {
91 dev_err(dev, "Invalid NVRAM magic\n");
95 len = le32_to_cpu(header.len);
97 data = kcalloc(1, len, GFP_KERNEL);
98 memcpy_fromio(data, priv->base, len);
101 err = brcm_nvram_add_cells(priv, data, len);
103 dev_err(dev, "Failed to add cells: %d\n", err);
112 static int brcm_nvram_probe(struct platform_device *pdev)
114 struct nvmem_config config = {
115 .name = "brcm-nvram",
116 .reg_read = brcm_nvram_read,
118 struct device *dev = &pdev->dev;
119 struct resource *res;
120 struct brcm_nvram *priv;
123 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
128 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
129 priv->base = devm_ioremap_resource(dev, res);
130 if (IS_ERR(priv->base))
131 return PTR_ERR(priv->base);
133 err = brcm_nvram_parse(priv);
138 config.cells = priv->cells;
139 config.ncells = priv->ncells;
141 config.size = resource_size(res);
143 return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &config));
146 static const struct of_device_id brcm_nvram_of_match_table[] = {
147 { .compatible = "brcm,nvram", },
151 static struct platform_driver brcm_nvram_driver = {
152 .probe = brcm_nvram_probe,
154 .name = "brcm_nvram",
155 .of_match_table = brcm_nvram_of_match_table,
159 static int __init brcm_nvram_init(void)
161 return platform_driver_register(&brcm_nvram_driver);
164 subsys_initcall_sync(brcm_nvram_init);
166 MODULE_AUTHOR("Rafał Miłecki");
167 MODULE_LICENSE("GPL");
168 MODULE_DEVICE_TABLE(of, brcm_nvram_of_match_table);