drivers/nvmem/mtk-efuse.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2015 MediaTek Inc.
   4  * Author: Andrew-CT Chen <andrew-ct.chen@mediatek.com>
   5  */
   6
   7 #include <linux/device.h>
   8 #include <linux/module.h>
   9 #include <linux/mod_devicetable.h>
  10 #include <linux/io.h>
  11 #include <linux/nvmem-provider.h>
  12 #include <linux/platform_device.h>
  13
  14 struct mtk_efuse_priv {
  15         void __iomem *base;
  16 };
  17
  18 static int mtk_reg_read(void *context,
  19                         unsigned int reg, void *_val, size_t bytes)
  20 {
  21         struct mtk_efuse_priv *priv = context;
  22         void __iomem *addr = priv->base + reg;
  23         u8 *val = _val;
  24         int i;
  25
  26         for (i = 0; i < bytes; i++, val++)
  27                 *val = readb(addr + i);
  28
  29         return 0;
  30 }
  31
  32 static int mtk_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 mtk_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.reg_read = mtk_reg_read;
  52         econfig.size = resource_size(res);
  53         econfig.priv = priv;
  54         econfig.dev = dev;
  55         nvmem = devm_nvmem_register(dev, &econfig);
  56
  57         return PTR_ERR_OR_ZERO(nvmem);
  58 }
  59
  60 static const struct of_device_id mtk_efuse_of_match[] = {
  61         { .compatible = "mediatek,mt8173-efuse",},
  62         { .compatible = "mediatek,efuse",},
  63         {/* sentinel */},
  64 };
  65 MODULE_DEVICE_TABLE(of, mtk_efuse_of_match);
  66
  67 static struct platform_driver mtk_efuse_driver = {
  68         .probe = mtk_efuse_probe,
  69         .driver = {
  70                 .name = "mediatek,efuse",
  71                 .of_match_table = mtk_efuse_of_match,
  72         },
  73 };
  74
  75 static int __init mtk_efuse_init(void)
  76 {
  77         int ret;
  78
  79         ret = platform_driver_register(&mtk_efuse_driver);
  80         if (ret) {
  81                 pr_err("Failed to register efuse driver\n");
  82                 return ret;
  83         }
  84
  85         return 0;
  86 }
  87
  88 static void __exit mtk_efuse_exit(void)
  89 {
  90         return platform_driver_unregister(&mtk_efuse_driver);
  91 }
  92
  93 subsys_initcall(mtk_efuse_init);
  94 module_exit(mtk_efuse_exit);
  95
  96 MODULE_AUTHOR("Andrew-CT Chen <andrew-ct.chen@mediatek.com>");
  97 MODULE_DESCRIPTION("Mediatek EFUSE driver");
  98 MODULE_LICENSE("GPL v2");