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"); 99