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 20 struct brcm_nvram { 21 struct device *dev; 22 void __iomem *base; 23 struct nvmem_cell_info *cells; 24 int ncells; 25 }; 26 27 struct 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 35 static 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(priv->base + offset++); 43 44 return 0; 45 } 46 47 static 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(buf, mac)) 56 return -EINVAL; 57 58 if (index) 59 eth_addr_add(mac, index); 60 61 ether_addr_copy(buf, mac); 62 63 return 0; 64 } 65 66 static 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, priv->ncells, 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, 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(dev->of_node, 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 } 110 111 static 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(header.magic, NVRAM_MAGIC, 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(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(data); 142 143 return 0; 144 } 145 146 static 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, 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, 0, &res); 163 if (IS_ERR(priv->base)) 164 return PTR_ERR(priv->base); 165 166 err = brcm_nvram_parse(priv); 167 if (err) 168 return err; 169 170 bcm47xx_nvram_init_from_iomem(priv->base, 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(devm_nvmem_register(dev, &config)); 179 } 180 181 static const struct of_device_id brcm_nvram_of_match_table[] = { 182 { .compatible = "brcm,nvram", }, 183 {}, 184 }; 185 186 static 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 }; 193 194 static int __init brcm_nvram_init(void) 195 { 196 return platform_driver_register(&brcm_nvram_driver); 197 } 198 199 subsys_initcall_sync(brcm_nvram_init); 200 201 MODULE_AUTHOR("Rafał Miłecki"); 202 MODULE_LICENSE("GPL"); 203 MODULE_DEVICE_TABLE(of, brcm_nvram_of_match_table); 204