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 = 1,
  18         FUSE_ELE = 2,
  19         FUSE_INVALID = -1
  20 };
  21
  22 struct ocotp_map_entry {
  23         u32 start; /* start word */
  24         u32 num; /* num words */
  25         enum fuse_type type;
  26 };
  27
  28 struct ocotp_devtype_data {
  29         u32 reg_off;
  30         char *name;
  31         u32 size;
  32         u32 num_entry;
  33         u32 flag;
  34         nvmem_reg_read_t reg_read;
  35         struct ocotp_map_entry entry[];
  36 };
  37
  38 struct imx_ocotp_priv {
  39         struct device *dev;
  40         void __iomem *base;
  41         struct nvmem_config config;
  42         struct mutex lock;
  43         const struct ocotp_devtype_data *data;
  44 };
  45
  46 static enum fuse_type imx_ocotp_fuse_type(void *context, u32 index)
  47 {
  48         struct imx_ocotp_priv *priv = context;
  49         const struct ocotp_devtype_data *data = priv->data;
  50         u32 start, end;
  51         int i;
  52
  53         for (i = 0; i < data->num_entry; i++) {
  54                 start = data->entry[i].start;
  55                 end = data->entry[i].start + data->entry[i].num;
  56
  57                 if (index >= start && index < end)
  58                         return data->entry[i].type;
  59         }
  60
  61         return FUSE_INVALID;
  62 }
  63
  64 static int imx_ocotp_reg_read(void *context, unsigned int offset, void *val, size_t bytes)
  65 {
  66         struct imx_ocotp_priv *priv = context;
  67         void __iomem *reg = priv->base + priv->data->reg_off;
  68         u32 count, index, num_bytes;
  69         enum fuse_type type;
  70         u32 *buf;
  71         void *p;
  72         int i;
  73
  74         index = offset;
  75         num_bytes = round_up(bytes, 4);
  76         count = num_bytes >> 2;
  77
  78         if (count > ((priv->data->size >> 2) - index))
  79                 count = (priv->data->size >> 2) - index;
  80
  81         p = kzalloc(num_bytes, GFP_KERNEL);
  82         if (!p)
  83                 return -ENOMEM;
  84
  85         mutex_lock(&priv->lock);
  86
  87         buf = p;
  88
  89         for (i = index; i < (index + count); i++) {
  90                 type = imx_ocotp_fuse_type(context, i);
  91                 if (type == FUSE_INVALID || type == FUSE_ELE) {
  92                         *buf++ = 0;
  93                         continue;
  94                 }
  95
  96                 *buf++ = readl_relaxed(reg + (i << 2));
  97         }
  98
  99         memcpy(val, (u8 *)p, bytes);
 100
 101         mutex_unlock(&priv->lock);
 102
 103         kfree(p);
 104
 105         return 0;
 106 };
 107
 108 static int imx_ele_ocotp_probe(struct platform_device *pdev)
 109 {
 110         struct device *dev = &pdev->dev;
 111         struct imx_ocotp_priv *priv;
 112         struct nvmem_device *nvmem;
 113
 114         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 115         if (!priv)
 116                 return -ENOMEM;
 117
 118         priv->data = of_device_get_match_data(dev);
 119
 120         priv->base = devm_platform_ioremap_resource(pdev, 0);
 121         if (IS_ERR(priv->base))
 122                 return PTR_ERR(priv->base);
 123
 124         priv->config.dev = dev;
 125         priv->config.name = "ELE-OCOTP";
 126         priv->config.id = NVMEM_DEVID_AUTO;
 127         priv->config.owner = THIS_MODULE;
 128         priv->config.size = priv->data->size;
 129         priv->config.reg_read = priv->data->reg_read;
 130         priv->config.word_size = 4;
 131         priv->config.stride = 1;
 132         priv->config.priv = priv;
 133         priv->config.read_only = true;
 134         mutex_init(&priv->lock);
 135
 136         nvmem = devm_nvmem_register(dev, &priv->config);
 137         if (IS_ERR(nvmem))
 138                 return PTR_ERR(nvmem);
 139
 140         return 0;
 141 }
 142
 143 static const struct ocotp_devtype_data imx93_ocotp_data = {
 144         .reg_off = 0x8000,
 145         .reg_read = imx_ocotp_reg_read,
 146         .size = 2048,
 147         .num_entry = 6,
 148         .entry = {
 149                 { 0, 52, FUSE_FSB },
 150                 { 63, 1, FUSE_ELE},
 151                 { 128, 16, FUSE_ELE },
 152                 { 182, 1, FUSE_ELE },
 153                 { 188, 1, FUSE_ELE },
 154                 { 312, 200, FUSE_FSB }
 155         },
 156 };
 157
 158 static const struct of_device_id imx_ele_ocotp_dt_ids[] = {
 159         { .compatible = "fsl,imx93-ocotp", .data = &imx93_ocotp_data, },
 160         {},
 161 };
 162 MODULE_DEVICE_TABLE(of, imx_ele_ocotp_dt_ids);
 163
 164 static struct platform_driver imx_ele_ocotp_driver = {
 165         .driver = {
 166                 .name = "imx_ele_ocotp",
 167                 .of_match_table = imx_ele_ocotp_dt_ids,
 168         },
 169         .probe = imx_ele_ocotp_probe,
 170 };
 171 module_platform_driver(imx_ele_ocotp_driver);
 172
 173 MODULE_DESCRIPTION("i.MX OCOTP/ELE driver");
 174 MODULE_AUTHOR("Peng Fan <peng.fan@nxp.com>");
 175 MODULE_LICENSE("GPL");