1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * UniPhier eFuse driver
4 *
5 * Copyright (C) 2017 Socionext Inc.
6 */
7
8#include <linux/device.h>
9#include <linux/io.h>
10#include <linux/module.h>
11#include <linux/mod_devicetable.h>
12#include <linux/nvmem-provider.h>
13#include <linux/platform_device.h>
14
15struct uniphier_efuse_priv {
16	void __iomem *base;
17};
18
19static int uniphier_reg_read(void *context,
20			     unsigned int reg, void *_val, size_t bytes)
21{
22	struct uniphier_efuse_priv *priv = context;
23	u8 *val = _val;
24	int offs;
25
26	for (offs = 0; offs < bytes; offs += sizeof(u8))
27		*val++ = readb(priv->base + reg + offs);
28
29	return 0;
30}
31
32static int uniphier_efuse_probe(struct platform_device *pdev)
33{
34	struct device *dev = &pdev->dev;
35	struct resource *res;
36	struct nvmem_device *nvmem;
37	struct nvmem_config econfig = {};
38	struct uniphier_efuse_priv *priv;
39
40	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
41	if (!priv)
42		return -ENOMEM;
43
44	priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
45	if (IS_ERR(priv->base))
46		return PTR_ERR(priv->base);
47
48	econfig.stride = 1;
49	econfig.word_size = 1;
50	econfig.read_only = true;
51	econfig.reg_read = uniphier_reg_read;
52	econfig.size = resource_size(res);
53	econfig.priv = priv;
54	econfig.dev = dev;
55	econfig.add_legacy_fixed_of_cells = true;
56	nvmem = devm_nvmem_register(dev, &econfig);
57
58	return PTR_ERR_OR_ZERO(nvmem);
59}
60
61static const struct of_device_id uniphier_efuse_of_match[] = {
62	{ .compatible = "socionext,uniphier-efuse",},
63	{/* sentinel */},
64};
65MODULE_DEVICE_TABLE(of, uniphier_efuse_of_match);
66
67static struct platform_driver uniphier_efuse_driver = {
68	.probe = uniphier_efuse_probe,
69	.driver = {
70		.name = "uniphier-efuse",
71		.of_match_table = uniphier_efuse_of_match,
72	},
73};
74module_platform_driver(uniphier_efuse_driver);
75
76MODULE_AUTHOR("Keiji Hayashibara <hayashibara.keiji@socionext.com>");
77MODULE_DESCRIPTION("UniPhier eFuse driver");
78MODULE_LICENSE("GPL v2");
79