1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * i.MX9 OCOTP fusebox driver 4 * 5 * Copyright 2023 NXP 6 */ 7 8 #include <linux/device.h> 9 #include <linux/io.h> 10 #include <linux/module.h> 11 #include <linux/nvmem-provider.h> 12 #include <linux/of.h> 13 #include <linux/platform_device.h> 14 #include <linux/slab.h> 15 16 enum fuse_type { 17 FUSE_FSB = BIT(0), 18 FUSE_ELE = BIT(1), 19 FUSE_ECC = BIT(2), 20 FUSE_INVALID = -1 21 }; 22 23 struct ocotp_map_entry { 24 u32 start; /* start word */ 25 u32 num; /* num words */ 26 enum fuse_type type; 27 }; 28 29 struct ocotp_devtype_data { 30 u32 reg_off; 31 char *name; 32 u32 size; 33 u32 num_entry; 34 u32 flag; 35 nvmem_reg_read_t reg_read; 36 struct ocotp_map_entry entry[]; 37 }; 38 39 struct imx_ocotp_priv { 40 struct device *dev; 41 void __iomem *base; 42 struct nvmem_config config; 43 struct mutex lock; 44 const struct ocotp_devtype_data *data; 45 }; 46 47 static enum fuse_type imx_ocotp_fuse_type(void *context, u32 index) 48 { 49 struct imx_ocotp_priv *priv = context; 50 const struct ocotp_devtype_data *data = priv->data; 51 u32 start, end; 52 int i; 53 54 for (i = 0; i < data->num_entry; i++) { 55 start = data->entry[i].start; 56 end = data->entry[i].start + data->entry[i].num; 57 58 if (index >= start && index < end) 59 return data->entry[i].type; 60 } 61 62 return FUSE_INVALID; 63 } 64 65 static int imx_ocotp_reg_read(void *context, unsigned int offset, void *val, size_t bytes) 66 { 67 struct imx_ocotp_priv *priv = context; 68 void __iomem *reg = priv->base + priv->data->reg_off; 69 u32 count, index, num_bytes; 70 enum fuse_type type; 71 u32 *buf; 72 void *p; 73 int i; 74 u8 skipbytes; 75 76 if (offset + bytes > priv->data->size) 77 bytes = priv->data->size - offset; 78 79 index = offset >> 2; 80 skipbytes = offset - (index << 2); 81 num_bytes = round_up(bytes + skipbytes, 4); 82 count = num_bytes >> 2; 83 84 p = kzalloc(num_bytes, GFP_KERNEL); 85 if (!p) 86 return -ENOMEM; 87 88 mutex_lock(&priv->lock); 89 90 buf = p; 91 92 for (i = index; i < (index + count); i++) { 93 type = imx_ocotp_fuse_type(context, i); 94 if (type == FUSE_INVALID || type == FUSE_ELE) { 95 *buf++ = 0; 96 continue; 97 } 98 99 if (type & FUSE_ECC) 100 *buf++ = readl_relaxed(reg + (i << 2)) & GENMASK(15, 0); 101 else 102 *buf++ = readl_relaxed(reg + (i << 2)); 103 } 104 105 memcpy(val, ((u8 *)p) + skipbytes, bytes); 106 107 mutex_unlock(&priv->lock); 108 109 kfree(p); 110 111 return 0; 112 }; 113 114 static int imx_ocotp_cell_pp(void *context, const char *id, int index, 115 unsigned int offset, void *data, size_t bytes) 116 { 117 u8 *buf = data; 118 int i; 119 120 /* Deal with some post processing of nvmem cell data */ 121 if (id && !strcmp(id, "mac-address")) 122 for (i = 0; i < bytes / 2; i++) 123 swap(buf[i], buf[bytes - i - 1]); 124 125 return 0; 126 } 127 128 static void imx_ocotp_fixup_dt_cell_info(struct nvmem_device *nvmem, 129 struct nvmem_cell_info *cell) 130 { 131 cell->read_post_process = imx_ocotp_cell_pp; 132 } 133 134 static int imx_ele_ocotp_probe(struct platform_device *pdev) 135 { 136 struct device *dev = &pdev->dev; 137 struct imx_ocotp_priv *priv; 138 struct nvmem_device *nvmem; 139 140 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 141 if (!priv) 142 return -ENOMEM; 143 144 priv->data = of_device_get_match_data(dev); 145 146 priv->base = devm_platform_ioremap_resource(pdev, 0); 147 if (IS_ERR(priv->base)) 148 return PTR_ERR(priv->base); 149 150 priv->config.dev = dev; 151 priv->config.name = "ELE-OCOTP"; 152 priv->config.id = NVMEM_DEVID_AUTO; 153 priv->config.owner = THIS_MODULE; 154 priv->config.size = priv->data->size; 155 priv->config.reg_read = priv->data->reg_read; 156 priv->config.word_size = 1; 157 priv->config.stride = 1; 158 priv->config.priv = priv; 159 priv->config.read_only = true; 160 priv->config.add_legacy_fixed_of_cells = true; 161 priv->config.fixup_dt_cell_info = imx_ocotp_fixup_dt_cell_info; 162 mutex_init(&priv->lock); 163 164 nvmem = devm_nvmem_register(dev, &priv->config); 165 if (IS_ERR(nvmem)) 166 return PTR_ERR(nvmem); 167 168 return 0; 169 } 170 171 static const struct ocotp_devtype_data imx93_ocotp_data = { 172 .reg_off = 0x8000, 173 .reg_read = imx_ocotp_reg_read, 174 .size = 2048, 175 .num_entry = 6, 176 .entry = { 177 { 0, 52, FUSE_FSB }, 178 { 63, 1, FUSE_ELE}, 179 { 128, 16, FUSE_ELE }, 180 { 182, 1, FUSE_ELE }, 181 { 188, 1, FUSE_ELE }, 182 { 312, 200, FUSE_FSB } 183 }, 184 }; 185 186 static const struct ocotp_devtype_data imx95_ocotp_data = { 187 .reg_off = 0x8000, 188 .reg_read = imx_ocotp_reg_read, 189 .size = 2048, 190 .num_entry = 12, 191 .entry = { 192 { 0, 1, FUSE_FSB | FUSE_ECC }, 193 { 7, 1, FUSE_FSB | FUSE_ECC }, 194 { 9, 3, FUSE_FSB | FUSE_ECC }, 195 { 12, 24, FUSE_FSB }, 196 { 36, 2, FUSE_FSB | FUSE_ECC }, 197 { 38, 14, FUSE_FSB }, 198 { 63, 1, FUSE_ELE }, 199 { 128, 16, FUSE_ELE }, 200 { 188, 1, FUSE_ELE }, 201 { 317, 2, FUSE_FSB | FUSE_ECC }, 202 { 320, 7, FUSE_FSB }, 203 { 328, 184, FUSE_FSB } 204 }, 205 }; 206 207 static const struct of_device_id imx_ele_ocotp_dt_ids[] = { 208 { .compatible = "fsl,imx93-ocotp", .data = &imx93_ocotp_data, }, 209 { .compatible = "fsl,imx95-ocotp", .data = &imx95_ocotp_data, }, 210 {}, 211 }; 212 MODULE_DEVICE_TABLE(of, imx_ele_ocotp_dt_ids); 213 214 static struct platform_driver imx_ele_ocotp_driver = { 215 .driver = { 216 .name = "imx_ele_ocotp", 217 .of_match_table = imx_ele_ocotp_dt_ids, 218 }, 219 .probe = imx_ele_ocotp_probe, 220 }; 221 module_platform_driver(imx_ele_ocotp_driver); 222 223 MODULE_DESCRIPTION("i.MX OCOTP/ELE driver"); 224 MODULE_AUTHOR("Peng Fan <peng.fan@nxp.com>"); 225 MODULE_LICENSE("GPL"); 226