drivers/nvmem/uniphier-efuse.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * UniPhier eFuse driver
0004  *
0005  * Copyright (C) 2017 Socionext Inc.
0006  */
0007
0008 #include <linux/device.h>
0009 #include <linux/io.h>
0010 #include <linux/module.h>
0011 #include <linux/mod_devicetable.h>
0012 #include <linux/nvmem-provider.h>
0013 #include <linux/platform_device.h>
0014
0015 struct uniphier_efuse_priv {
0016     void __iomem *base;
0017 };
0018
0019 static int uniphier_reg_read(void *context,
0020                  unsigned int reg, void *_val, size_t bytes)
0021 {
0022     struct uniphier_efuse_priv *priv = context;
0023     u8 *val = _val;
0024     int offs;
0025
0026     for (offs = 0; offs < bytes; offs += sizeof(u8))
0027         *val++ = readb(priv->base + reg + offs);
0028
0029     return 0;
0030 }
0031
0032 static int uniphier_efuse_probe(struct platform_device *pdev)
0033 {
0034     struct device *dev = &pdev->dev;
0035     struct resource *res;
0036     struct nvmem_device *nvmem;
0037     struct nvmem_config econfig = {};
0038     struct uniphier_efuse_priv *priv;
0039
0040     priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
0041     if (!priv)
0042         return -ENOMEM;
0043
0044     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0045     priv->base = devm_ioremap_resource(dev, res);
0046     if (IS_ERR(priv->base))
0047         return PTR_ERR(priv->base);
0048
0049     econfig.stride = 1;
0050     econfig.word_size = 1;
0051     econfig.read_only = true;
0052     econfig.reg_read = uniphier_reg_read;
0053     econfig.size = resource_size(res);
0054     econfig.priv = priv;
0055     econfig.dev = dev;
0056     nvmem = devm_nvmem_register(dev, &econfig);
0057
0058     return PTR_ERR_OR_ZERO(nvmem);
0059 }
0060
0061 static const struct of_device_id uniphier_efuse_of_match[] = {
0062     { .compatible = "socionext,uniphier-efuse",},
0063     {/* sentinel */},
0064 };
0065 MODULE_DEVICE_TABLE(of, uniphier_efuse_of_match);
0066
0067 static struct platform_driver uniphier_efuse_driver = {
0068     .probe = uniphier_efuse_probe,
0069     .driver = {
0070         .name = "uniphier-efuse",
0071         .of_match_table = uniphier_efuse_of_match,
0072     },
0073 };
0074 module_platform_driver(uniphier_efuse_driver);
0075
0076 MODULE_AUTHOR("Keiji Hayashibara <hayashibara.keiji@socionext.com>");
0077 MODULE_DESCRIPTION("UniPhier eFuse driver");
0078 MODULE_LICENSE("GPL v2");