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/mod_devicetable.h> 20 #include <linux/nvmem-provider.h> 21 #include <linux/platform_device.h> 22 23 struct uniphier_efuse_priv { 24 void __iomem *base; 25 }; 26 27 static int uniphier_reg_read(void *context, 28 unsigned int reg, void *_val, size_t bytes) 29 { 30 struct uniphier_efuse_priv *priv = context; 31 u8 *val = _val; 32 int offs; 33 34 for (offs = 0; offs < bytes; offs += sizeof(u8)) 35 *val++ = readb(priv->base + reg + offs); 36 37 return 0; 38 } 39 40 static int uniphier_efuse_probe(struct platform_device *pdev) 41 { 42 struct device *dev = &pdev->dev; 43 struct resource *res; 44 struct nvmem_device *nvmem; 45 struct nvmem_config econfig = {}; 46 struct uniphier_efuse_priv *priv; 47 48 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 49 if (!priv) 50 return -ENOMEM; 51 52 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 53 priv->base = devm_ioremap_resource(dev, res); 54 if (IS_ERR(priv->base)) 55 return PTR_ERR(priv->base); 56 57 econfig.stride = 1; 58 econfig.word_size = 1; 59 econfig.read_only = true; 60 econfig.reg_read = uniphier_reg_read; 61 econfig.size = resource_size(res); 62 econfig.priv = priv; 63 econfig.dev = dev; 64 nvmem = devm_nvmem_register(dev, &econfig); 65 66 return PTR_ERR_OR_ZERO(nvmem); 67 } 68 69 static const struct of_device_id uniphier_efuse_of_match[] = { 70 { .compatible = "socionext,uniphier-efuse",}, 71 {/* sentinel */}, 72 }; 73 MODULE_DEVICE_TABLE(of, uniphier_efuse_of_match); 74 75 static struct platform_driver uniphier_efuse_driver = { 76 .probe = uniphier_efuse_probe, 77 .driver = { 78 .name = "uniphier-efuse", 79 .of_match_table = uniphier_efuse_of_match, 80 }, 81 }; 82 module_platform_driver(uniphier_efuse_driver); 83 84 MODULE_AUTHOR("Keiji Hayashibara <hayashibara.keiji@socionext.com>"); 85 MODULE_DESCRIPTION("UniPhier eFuse driver"); 86 MODULE_LICENSE("GPL v2"); 87