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
  75         index = offset;
  76         num_bytes = round_up(bytes, 4);
  77         count = num_bytes >> 2;
  78
  79         if (count > ((priv->data->size >> 2) - index))
  80                 count = (priv->data->size >> 2) - index;
  81
  82         p = kzalloc(num_bytes, GFP_KERNEL);
  83         if (!p)
  84                 return -ENOMEM;
  85
  86         mutex_lock(&priv->lock);
  87
  88         buf = p;
  89
  90         for (i = index; i < (index + count); i++) {
  91                 type = imx_ocotp_fuse_type(context, i);
  92                 if (type == FUSE_INVALID || type == FUSE_ELE) {
  93                         *buf++ = 0;
  94                         continue;
  95                 }
  96
  97                 if (type & FUSE_ECC)
  98                         *buf++ = readl_relaxed(reg + (i << 2)) & GENMASK(15, 0);
  99                 else
 100                         *buf++ = readl_relaxed(reg + (i << 2));
 101         }
 102
 103         memcpy(val, (u8 *)p, bytes);
 104
 105         mutex_unlock(&priv->lock);
 106
 107         kfree(p);
 108
 109         return 0;
 110 };
 111
 112 static int imx_ele_ocotp_probe(struct platform_device *pdev)
 113 {
 114         struct device *dev = &pdev->dev;
 115         struct imx_ocotp_priv *priv;
 116         struct nvmem_device *nvmem;
 117
 118         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 119         if (!priv)
 120                 return -ENOMEM;
 121
 122         priv->data = of_device_get_match_data(dev);
 123
 124         priv->base = devm_platform_ioremap_resource(pdev, 0);
 125         if (IS_ERR(priv->base))
 126                 return PTR_ERR(priv->base);
 127
 128         priv->config.dev = dev;
 129         priv->config.name = "ELE-OCOTP";
 130         priv->config.id = NVMEM_DEVID_AUTO;
 131         priv->config.owner = THIS_MODULE;
 132         priv->config.size = priv->data->size;
 133         priv->config.reg_read = priv->data->reg_read;
 134         priv->config.word_size = 4;
 135         priv->config.stride = 1;
 136         priv->config.priv = priv;
 137         priv->config.read_only = true;
 138         mutex_init(&priv->lock);
 139
 140         nvmem = devm_nvmem_register(dev, &priv->config);
 141         if (IS_ERR(nvmem))
 142                 return PTR_ERR(nvmem);
 143
 144         return 0;
 145 }
 146
 147 static const struct ocotp_devtype_data imx93_ocotp_data = {
 148         .reg_off = 0x8000,
 149         .reg_read = imx_ocotp_reg_read,
 150         .size = 2048,
 151         .num_entry = 6,
 152         .entry = {
 153                 { 0, 52, FUSE_FSB },
 154                 { 63, 1, FUSE_ELE},
 155                 { 128, 16, FUSE_ELE },
 156                 { 182, 1, FUSE_ELE },
 157                 { 188, 1, FUSE_ELE },
 158                 { 312, 200, FUSE_FSB }
 159         },
 160 };
 161
 162 static const struct ocotp_devtype_data imx95_ocotp_data = {
 163         .reg_off = 0x8000,
 164         .reg_read = imx_ocotp_reg_read,
 165         .size = 2048,
 166         .num_entry = 12,
 167         .entry = {
 168                 { 0, 1, FUSE_FSB | FUSE_ECC },
 169                 { 7, 1, FUSE_FSB | FUSE_ECC },
 170                 { 9, 3, FUSE_FSB | FUSE_ECC },
 171                 { 12, 24, FUSE_FSB },
 172                 { 36, 2, FUSE_FSB  | FUSE_ECC },
 173                 { 38, 14, FUSE_FSB },
 174                 { 63, 1, FUSE_ELE },
 175                 { 128, 16, FUSE_ELE },
 176                 { 188, 1, FUSE_ELE },
 177                 { 317, 2, FUSE_FSB | FUSE_ECC },
 178                 { 320, 7, FUSE_FSB },
 179                 { 328, 184, FUSE_FSB }
 180         },
 181 };
 182
 183 static const struct of_device_id imx_ele_ocotp_dt_ids[] = {
 184         { .compatible = "fsl,imx93-ocotp", .data = &imx93_ocotp_data, },
 185         { .compatible = "fsl,imx95-ocotp", .data = &imx95_ocotp_data, },
 186         {},
 187 };
 188 MODULE_DEVICE_TABLE(of, imx_ele_ocotp_dt_ids);
 189
 190 static struct platform_driver imx_ele_ocotp_driver = {
 191         .driver = {
 192                 .name = "imx_ele_ocotp",
 193                 .of_match_table = imx_ele_ocotp_dt_ids,
 194         },
 195         .probe = imx_ele_ocotp_probe,
 196 };
 197 module_platform_driver(imx_ele_ocotp_driver);
 198
 199 MODULE_DESCRIPTION("i.MX OCOTP/ELE driver");
 200 MODULE_AUTHOR("Peng Fan <peng.fan@nxp.com>");
 201 MODULE_LICENSE("GPL");