drivers/nvmem/imx-ocotp-ele.c

   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 <[email protected]>");
 225 MODULE_LICENSE("GPL");