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
23struct uniphier_efuse_priv {
24 void __iomem *base;
25};
26
27static 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
40static 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
69static const struct of_device_id uniphier_efuse_of_match[] = {
70 { .compatible = "socionext,uniphier-efuse",},
71 {/* sentinel */},
72};
73MODULE_DEVICE_TABLE(of, uniphier_efuse_of_match);
74
75static 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};
82module_platform_driver(uniphier_efuse_driver);
83
84MODULE_AUTHOR("Keiji Hayashibara <hayashibara.keiji@socionext.com>");
85MODULE_DESCRIPTION("UniPhier eFuse driver");
86MODULE_LICENSE("GPL v2");
87