1 /* 2 * Copyright (c) 2015 MediaTek Inc. 3 * Author: Andrew-CT Chen <andrew-ct.chen@mediatek.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 */ 14 15 #include <linux/device.h> 16 #include <linux/module.h> 17 #include <linux/io.h> 18 #include <linux/nvmem-provider.h> 19 #include <linux/platform_device.h> 20 21 struct mtk_efuse_priv { 22 void __iomem *base; 23 }; 24 25 static int mtk_reg_read(void *context, 26 unsigned int reg, void *_val, size_t bytes) 27 { 28 struct mtk_efuse_priv *priv = context; 29 u32 *val = _val; 30 int i = 0, words = bytes / 4; 31 32 while (words--) 33 *val++ = readl(priv->base + reg + (i++ * 4)); 34 35 return 0; 36 } 37 38 static int mtk_reg_write(void *context, 39 unsigned int reg, void *_val, size_t bytes) 40 { 41 struct mtk_efuse_priv *priv = context; 42 u32 *val = _val; 43 int i = 0, words = bytes / 4; 44 45 while (words--) 46 writel(*val++, priv->base + reg + (i++ * 4)); 47 48 return 0; 49 } 50 51 static int mtk_efuse_probe(struct platform_device *pdev) 52 { 53 struct device *dev = &pdev->dev; 54 struct resource *res; 55 struct nvmem_device *nvmem; 56 struct nvmem_config econfig = {}; 57 struct mtk_efuse_priv *priv; 58 59 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 60 if (!priv) 61 return -ENOMEM; 62 63 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 64 priv->base = devm_ioremap_resource(dev, res); 65 if (IS_ERR(priv->base)) 66 return PTR_ERR(priv->base); 67 68 econfig.stride = 4; 69 econfig.word_size = 4; 70 econfig.reg_read = mtk_reg_read; 71 econfig.reg_write = mtk_reg_write; 72 econfig.size = resource_size(res); 73 econfig.priv = priv; 74 econfig.dev = dev; 75 nvmem = devm_nvmem_register(dev, &econfig); 76 77 return PTR_ERR_OR_ZERO(nvmem); 78 } 79 80 static const struct of_device_id mtk_efuse_of_match[] = { 81 { .compatible = "mediatek,mt8173-efuse",}, 82 { .compatible = "mediatek,efuse",}, 83 {/* sentinel */}, 84 }; 85 MODULE_DEVICE_TABLE(of, mtk_efuse_of_match); 86 87 static struct platform_driver mtk_efuse_driver = { 88 .probe = mtk_efuse_probe, 89 .driver = { 90 .name = "mediatek,efuse", 91 .of_match_table = mtk_efuse_of_match, 92 }, 93 }; 94 95 static int __init mtk_efuse_init(void) 96 { 97 int ret; 98 99 ret = platform_driver_register(&mtk_efuse_driver); 100 if (ret) { 101 pr_err("Failed to register efuse driver\n"); 102 return ret; 103 } 104 105 return 0; 106 } 107 108 static void __exit mtk_efuse_exit(void) 109 { 110 return platform_driver_unregister(&mtk_efuse_driver); 111 } 112 113 subsys_initcall(mtk_efuse_init); 114 module_exit(mtk_efuse_exit); 115 116 MODULE_AUTHOR("Andrew-CT Chen <andrew-ct.chen@mediatek.com>"); 117 MODULE_DESCRIPTION("Mediatek EFUSE driver"); 118 MODULE_LICENSE("GPL v2"); 119