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         u32 *val = _val;
  23         int i = 0, words = bytes / 4;
  24
  25         while (words--)
  26                 *val++ = readl(priv->base + reg + (i++ * 4));
  27
  28         return 0;
  29 }
  30
  31 static int mtk_efuse_probe(struct platform_device *pdev)
  32 {
  33         struct device *dev = &pdev->dev;
  34         struct resource *res;
  35         struct nvmem_device *nvmem;
  36         struct nvmem_config econfig = {};
  37         struct mtk_efuse_priv *priv;
  38
  39         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  40         if (!priv)
  41                 return -ENOMEM;
  42
  43         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  44         priv->base = devm_ioremap_resource(dev, res);
  45         if (IS_ERR(priv->base))
  46                 return PTR_ERR(priv->base);
  47
  48         econfig.stride = 4;
  49         econfig.word_size = 4;
  50         econfig.reg_read = mtk_reg_read;
  51         econfig.size = resource_size(res);
  52         econfig.priv = priv;
  53         econfig.dev = dev;
  54         nvmem = devm_nvmem_register(dev, &econfig);
  55
  56         return PTR_ERR_OR_ZERO(nvmem);
  57 }
  58
  59 static const struct of_device_id mtk_efuse_of_match[] = {
  60         { .compatible = "mediatek,mt8173-efuse",},
  61         { .compatible = "mediatek,efuse",},
  62         {/* sentinel */},
  63 };
  64 MODULE_DEVICE_TABLE(of, mtk_efuse_of_match);
  65
  66 static struct platform_driver mtk_efuse_driver = {
  67         .probe = mtk_efuse_probe,
  68         .driver = {
  69                 .name = "mediatek,efuse",
  70                 .of_match_table = mtk_efuse_of_match,
  71         },
  72 };
  73
  74 static int __init mtk_efuse_init(void)
  75 {
  76         int ret;
  77
  78         ret = platform_driver_register(&mtk_efuse_driver);
  79         if (ret) {
  80                 pr_err("Failed to register efuse driver\n");
  81                 return ret;
  82         }
  83
  84         return 0;
  85 }
  86
  87 static void __exit mtk_efuse_exit(void)
  88 {
  89         return platform_driver_unregister(&mtk_efuse_driver);
  90 }
  91
  92 subsys_initcall(mtk_efuse_init);
  93 module_exit(mtk_efuse_exit);
  94
  95 MODULE_AUTHOR("Andrew-CT Chen <andrew-ct.chen@mediatek.com>");
  96 MODULE_DESCRIPTION("Mediatek EFUSE driver");
  97 MODULE_LICENSE("GPL v2");