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 static int mtk_reg_read(void *context, 22 unsigned int reg, void *_val, size_t bytes) 23 { 24 void __iomem *base = context; 25 u32 *val = _val; 26 int i = 0, words = bytes / 4; 27 28 while (words--) 29 *val++ = readl(base + reg + (i++ * 4)); 30 31 return 0; 32 } 33 34 static int mtk_reg_write(void *context, 35 unsigned int reg, void *_val, size_t bytes) 36 { 37 void __iomem *base = context; 38 u32 *val = _val; 39 int i = 0, words = bytes / 4; 40 41 while (words--) 42 writel(*val++, base + reg + (i++ * 4)); 43 44 return 0; 45 } 46 47 static int mtk_efuse_probe(struct platform_device *pdev) 48 { 49 struct device *dev = &pdev->dev; 50 struct resource *res; 51 struct nvmem_device *nvmem; 52 struct nvmem_config *econfig; 53 void __iomem *base; 54 55 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 56 base = devm_ioremap_resource(dev, res); 57 if (IS_ERR(base)) 58 return PTR_ERR(base); 59 60 econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL); 61 if (!econfig) 62 return -ENOMEM; 63 64 econfig->stride = 4; 65 econfig->word_size = 4; 66 econfig->reg_read = mtk_reg_read; 67 econfig->reg_write = mtk_reg_write; 68 econfig->size = resource_size(res); 69 econfig->priv = base; 70 econfig->dev = dev; 71 econfig->owner = THIS_MODULE; 72 nvmem = nvmem_register(econfig); 73 if (IS_ERR(nvmem)) 74 return PTR_ERR(nvmem); 75 76 platform_set_drvdata(pdev, nvmem); 77 78 return 0; 79 } 80 81 static int mtk_efuse_remove(struct platform_device *pdev) 82 { 83 struct nvmem_device *nvmem = platform_get_drvdata(pdev); 84 85 return nvmem_unregister(nvmem); 86 } 87 88 static const struct of_device_id mtk_efuse_of_match[] = { 89 { .compatible = "mediatek,mt8173-efuse",}, 90 { .compatible = "mediatek,efuse",}, 91 {/* sentinel */}, 92 }; 93 MODULE_DEVICE_TABLE(of, mtk_efuse_of_match); 94 95 static struct platform_driver mtk_efuse_driver = { 96 .probe = mtk_efuse_probe, 97 .remove = mtk_efuse_remove, 98 .driver = { 99 .name = "mediatek,efuse", 100 .of_match_table = mtk_efuse_of_match, 101 }, 102 }; 103 104 static int __init mtk_efuse_init(void) 105 { 106 int ret; 107 108 ret = platform_driver_register(&mtk_efuse_driver); 109 if (ret) { 110 pr_err("Failed to register efuse driver\n"); 111 return ret; 112 } 113 114 return 0; 115 } 116 117 static void __exit mtk_efuse_exit(void) 118 { 119 return platform_driver_unregister(&mtk_efuse_driver); 120 } 121 122 subsys_initcall(mtk_efuse_init); 123 module_exit(mtk_efuse_exit); 124 125 MODULE_AUTHOR("Andrew-CT Chen <andrew-ct.chen@mediatek.com>"); 126 MODULE_DESCRIPTION("Mediatek EFUSE driver"); 127 MODULE_LICENSE("GPL v2"); 128