drivers/nvmem/mtk-efuse.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (c) 2015 MediaTek Inc.
0004  * Author: Andrew-CT Chen <andrew-ct.chen@mediatek.com>
0005  */
0006
0007 #include <linux/device.h>
0008 #include <linux/module.h>
0009 #include <linux/mod_devicetable.h>
0010 #include <linux/io.h>
0011 #include <linux/nvmem-provider.h>
0012 #include <linux/platform_device.h>
0013
0014 struct mtk_efuse_priv {
0015     void __iomem *base;
0016 };
0017
0018 static int mtk_reg_read(void *context,
0019             unsigned int reg, void *_val, size_t bytes)
0020 {
0021     struct mtk_efuse_priv *priv = context;
0022     void __iomem *addr = priv->base + reg;
0023     u8 *val = _val;
0024     int i;
0025
0026     for (i = 0; i < bytes; i++, val++)
0027         *val = readb(addr + i);
0028
0029     return 0;
0030 }
0031
0032 static int mtk_efuse_probe(struct platform_device *pdev)
0033 {
0034     struct device *dev = &pdev->dev;
0035     struct resource *res;
0036     struct nvmem_device *nvmem;
0037     struct nvmem_config econfig = {};
0038     struct mtk_efuse_priv *priv;
0039
0040     priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
0041     if (!priv)
0042         return -ENOMEM;
0043
0044     priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
0045     if (IS_ERR(priv->base))
0046         return PTR_ERR(priv->base);
0047
0048     econfig.stride = 1;
0049     econfig.word_size = 1;
0050     econfig.reg_read = mtk_reg_read;
0051     econfig.size = resource_size(res);
0052     econfig.priv = priv;
0053     econfig.dev = dev;
0054     nvmem = devm_nvmem_register(dev, &econfig);
0055
0056     return PTR_ERR_OR_ZERO(nvmem);
0057 }
0058
0059 static const struct of_device_id mtk_efuse_of_match[] = {
0060     { .compatible = "mediatek,mt8173-efuse",},
0061     { .compatible = "mediatek,efuse",},
0062     {/* sentinel */},
0063 };
0064 MODULE_DEVICE_TABLE(of, mtk_efuse_of_match);
0065
0066 static struct platform_driver mtk_efuse_driver = {
0067     .probe = mtk_efuse_probe,
0068     .driver = {
0069         .name = "mediatek,efuse",
0070         .of_match_table = mtk_efuse_of_match,
0071     },
0072 };
0073
0074 static int __init mtk_efuse_init(void)
0075 {
0076     int ret;
0077
0078     ret = platform_driver_register(&mtk_efuse_driver);
0079     if (ret) {
0080         pr_err("Failed to register efuse driver\n");
0081         return ret;
0082     }
0083
0084     return 0;
0085 }
0086
0087 static void __exit mtk_efuse_exit(void)
0088 {
0089     return platform_driver_unregister(&mtk_efuse_driver);
0090 }
0091
0092 subsys_initcall(mtk_efuse_init);
0093 module_exit(mtk_efuse_exit);
0094
0095 MODULE_AUTHOR("Andrew-CT Chen <andrew-ct.chen@mediatek.com>");
0096 MODULE_DESCRIPTION("Mediatek EFUSE driver");
0097 MODULE_LICENSE("GPL v2");