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 <[email protected]>
   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_reg_write(void *context,
  32                          unsigned int reg, void *_val, size_t bytes)
  33 {
  34         struct mtk_efuse_priv *priv = context;
  35         u32 *val = _val;
  36         int i = 0, words = bytes / 4;
  37
  38         while (words--)
  39                 writel(*val++, priv->base + reg + (i++ * 4));
  40
  41         return 0;
  42 }
  43
  44 static int mtk_efuse_probe(struct platform_device *pdev)
  45 {
  46         struct device *dev = &pdev->dev;
  47         struct resource *res;
  48         struct nvmem_device *nvmem;
  49         struct nvmem_config econfig = {};
  50         struct mtk_efuse_priv *priv;
  51
  52         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  53         if (!priv)
  54                 return -ENOMEM;
  55
  56         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  57         priv->base = devm_ioremap_resource(dev, res);
  58         if (IS_ERR(priv->base))
  59                 return PTR_ERR(priv->base);
  60
  61         econfig.stride = 4;
  62         econfig.word_size = 4;
  63         econfig.reg_read = mtk_reg_read;
  64         econfig.reg_write = mtk_reg_write;
  65         econfig.size = resource_size(res);
  66         econfig.priv = priv;
  67         econfig.dev = dev;
  68         nvmem = devm_nvmem_register(dev, &econfig);
  69
  70         return PTR_ERR_OR_ZERO(nvmem);
  71 }
  72
  73 static const struct of_device_id mtk_efuse_of_match[] = {
  74         { .compatible = "mediatek,mt8173-efuse",},
  75         { .compatible = "mediatek,efuse",},
  76         {/* sentinel */},
  77 };
  78 MODULE_DEVICE_TABLE(of, mtk_efuse_of_match);
  79
  80 static struct platform_driver mtk_efuse_driver = {
  81         .probe = mtk_efuse_probe,
  82         .driver = {
  83                 .name = "mediatek,efuse",
  84                 .of_match_table = mtk_efuse_of_match,
  85         },
  86 };
  87
  88 static int __init mtk_efuse_init(void)
  89 {
  90         int ret;
  91
  92         ret = platform_driver_register(&mtk_efuse_driver);
  93         if (ret) {
  94                 pr_err("Failed to register efuse driver\n");
  95                 return ret;
  96         }
  97
  98         return 0;
  99 }
 100
 101 static void __exit mtk_efuse_exit(void)
 102 {
 103         return platform_driver_unregister(&mtk_efuse_driver);
 104 }
 105
 106 subsys_initcall(mtk_efuse_init);
 107 module_exit(mtk_efuse_exit);
 108
 109 MODULE_AUTHOR("Andrew-CT Chen <[email protected]>");
 110 MODULE_DESCRIPTION("Mediatek EFUSE driver");
 111 MODULE_LICENSE("GPL v2");