drivers/nvmem/uniphier-efuse.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * UniPhier eFuse driver
   4  *
   5  * Copyright (C) 2017 Socionext Inc.
   6  */
   7
   8 #include <linux/device.h>
   9 #include <linux/io.h>
  10 #include <linux/module.h>
  11 #include <linux/mod_devicetable.h>
  12 #include <linux/nvmem-provider.h>
  13 #include <linux/platform_device.h>
  14
  15 struct uniphier_efuse_priv {
  16         void __iomem *base;
  17 };
  18
  19 static int uniphier_reg_read(void *context,
  20                              unsigned int reg, void *_val, size_t bytes)
  21 {
  22         struct uniphier_efuse_priv *priv = context;
  23         u8 *val = _val;
  24         int offs;
  25
  26         for (offs = 0; offs < bytes; offs += sizeof(u8))
  27                 *val++ = readb(priv->base + reg + offs);
  28
  29         return 0;
  30 }
  31
  32 static int uniphier_efuse_probe(struct platform_device *pdev)
  33 {
  34         struct device *dev = &pdev->dev;
  35         struct resource *res;
  36         struct nvmem_device *nvmem;
  37         struct nvmem_config econfig = {};
  38         struct uniphier_efuse_priv *priv;
  39
  40         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  41         if (!priv)
  42                 return -ENOMEM;
  43
  44         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  45         priv->base = devm_ioremap_resource(dev, res);
  46         if (IS_ERR(priv->base))
  47                 return PTR_ERR(priv->base);
  48
  49         econfig.stride = 1;
  50         econfig.word_size = 1;
  51         econfig.read_only = true;
  52         econfig.reg_read = uniphier_reg_read;
  53         econfig.size = resource_size(res);
  54         econfig.priv = priv;
  55         econfig.dev = dev;
  56         nvmem = devm_nvmem_register(dev, &econfig);
  57
  58         return PTR_ERR_OR_ZERO(nvmem);
  59 }
  60
  61 static const struct of_device_id uniphier_efuse_of_match[] = {
  62         { .compatible = "socionext,uniphier-efuse",},
  63         {/* sentinel */},
  64 };
  65 MODULE_DEVICE_TABLE(of, uniphier_efuse_of_match);
  66
  67 static struct platform_driver uniphier_efuse_driver = {
  68         .probe = uniphier_efuse_probe,
  69         .driver = {
  70                 .name = "uniphier-efuse",
  71                 .of_match_table = uniphier_efuse_of_match,
  72         },
  73 };
  74 module_platform_driver(uniphier_efuse_driver);
  75
  76 MODULE_AUTHOR("Keiji Hayashibara <hayashibara.keiji@socionext.com>");
  77 MODULE_DESCRIPTION("UniPhier eFuse driver");
  78 MODULE_LICENSE("GPL v2");