1 /* 2 * UniPhier eFuse driver 3 * 4 * Copyright (C) 2017 Socionext Inc. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 #include <linux/device.h> 17 #include <linux/io.h> 18 #include <linux/module.h> 19 #include <linux/nvmem-provider.h> 20 #include <linux/platform_device.h> 21 22 struct uniphier_efuse_priv { 23 void __iomem *base; 24 }; 25 26 static int uniphier_reg_read(void *context, 27 unsigned int reg, void *_val, size_t bytes) 28 { 29 struct uniphier_efuse_priv *priv = context; 30 u8 *val = _val; 31 int offs; 32 33 for (offs = 0; offs < bytes; offs += sizeof(u8)) 34 *val++ = readb(priv->base + reg + offs); 35 36 return 0; 37 } 38 39 static int uniphier_efuse_probe(struct platform_device *pdev) 40 { 41 struct device *dev = &pdev->dev; 42 struct resource *res; 43 struct nvmem_device *nvmem; 44 struct nvmem_config econfig = {}; 45 struct uniphier_efuse_priv *priv; 46 47 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 48 if (!priv) 49 return -ENOMEM; 50 51 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 52 priv->base = devm_ioremap_resource(dev, res); 53 if (IS_ERR(priv->base)) 54 return PTR_ERR(priv->base); 55 56 econfig.stride = 1; 57 econfig.word_size = 1; 58 econfig.read_only = true; 59 econfig.reg_read = uniphier_reg_read; 60 econfig.size = resource_size(res); 61 econfig.priv = priv; 62 econfig.dev = dev; 63 nvmem = nvmem_register(&econfig); 64 if (IS_ERR(nvmem)) 65 return PTR_ERR(nvmem); 66 67 platform_set_drvdata(pdev, nvmem); 68 69 return 0; 70 } 71 72 static int uniphier_efuse_remove(struct platform_device *pdev) 73 { 74 struct nvmem_device *nvmem = platform_get_drvdata(pdev); 75 76 return nvmem_unregister(nvmem); 77 } 78 79 static const struct of_device_id uniphier_efuse_of_match[] = { 80 { .compatible = "socionext,uniphier-efuse",}, 81 {/* sentinel */}, 82 }; 83 MODULE_DEVICE_TABLE(of, uniphier_efuse_of_match); 84 85 static struct platform_driver uniphier_efuse_driver = { 86 .probe = uniphier_efuse_probe, 87 .remove = uniphier_efuse_remove, 88 .driver = { 89 .name = "uniphier-efuse", 90 .of_match_table = uniphier_efuse_of_match, 91 }, 92 }; 93 module_platform_driver(uniphier_efuse_driver); 94 95 MODULE_AUTHOR("Keiji Hayashibara <hayashibara.keiji@socionext.com>"); 96 MODULE_DESCRIPTION("UniPhier eFuse driver"); 97 MODULE_LICENSE("GPL v2"); 98