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/mod_devicetable.h> 18 #include <linux/io.h> 19 #include <linux/nvmem-provider.h> 20 #include <linux/platform_device.h> 21 22 struct mtk_efuse_priv { 23 void __iomem *base; 24 }; 25 26 static int mtk_reg_read(void *context, 27 unsigned int reg, void *_val, size_t bytes) 28 { 29 struct mtk_efuse_priv *priv = context; 30 u32 *val = _val; 31 int i = 0, words = bytes / 4; 32 33 while (words--) 34 *val++ = readl(priv->base + reg + (i++ * 4)); 35 36 return 0; 37 } 38 39 static int mtk_reg_write(void *context, 40 unsigned int reg, void *_val, size_t bytes) 41 { 42 struct mtk_efuse_priv *priv = context; 43 u32 *val = _val; 44 int i = 0, words = bytes / 4; 45 46 while (words--) 47 writel(*val++, priv->base + reg + (i++ * 4)); 48 49 return 0; 50 } 51 52 static int mtk_efuse_probe(struct platform_device *pdev) 53 { 54 struct device *dev = &pdev->dev; 55 struct resource *res; 56 struct nvmem_device *nvmem; 57 struct nvmem_config econfig = {}; 58 struct mtk_efuse_priv *priv; 59 60 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 61 if (!priv) 62 return -ENOMEM; 63 64 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 65 priv->base = devm_ioremap_resource(dev, res); 66 if (IS_ERR(priv->base)) 67 return PTR_ERR(priv->base); 68 69 econfig.stride = 4; 70 econfig.word_size = 4; 71 econfig.reg_read = mtk_reg_read; 72 econfig.reg_write = mtk_reg_write; 73 econfig.size = resource_size(res); 74 econfig.priv = priv; 75 econfig.dev = dev; 76 nvmem = devm_nvmem_register(dev, &econfig); 77 78 return PTR_ERR_OR_ZERO(nvmem); 79 } 80 81 static const struct of_device_id mtk_efuse_of_match[] = { 82 { .compatible = "mediatek,mt8173-efuse",}, 83 { .compatible = "mediatek,efuse",}, 84 {/* sentinel */}, 85 }; 86 MODULE_DEVICE_TABLE(of, mtk_efuse_of_match); 87 88 static struct platform_driver mtk_efuse_driver = { 89 .probe = mtk_efuse_probe, 90 .driver = { 91 .name = "mediatek,efuse", 92 .of_match_table = mtk_efuse_of_match, 93 }, 94 }; 95 96 static int __init mtk_efuse_init(void) 97 { 98 int ret; 99 100 ret = platform_driver_register(&mtk_efuse_driver); 101 if (ret) { 102 pr_err("Failed to register efuse driver\n"); 103 return ret; 104 } 105 106 return 0; 107 } 108 109 static void __exit mtk_efuse_exit(void) 110 { 111 return platform_driver_unregister(&mtk_efuse_driver); 112 } 113 114 subsys_initcall(mtk_efuse_init); 115 module_exit(mtk_efuse_exit); 116 117 MODULE_AUTHOR("Andrew-CT Chen <andrew-ct.chen@mediatek.com>"); 118 MODULE_DESCRIPTION("Mediatek EFUSE driver"); 119 MODULE_LICENSE("GPL v2"); 120