1// SPDX-License-Identifier: GPL-2.0
2/*
3 *  Copyright (C) 2023  Westermo Network Technologies AB
4 */
5
6#include <linux/device.h>
7#include <linux/io.h>
8#include <linux/module.h>
9#include <linux/mod_devicetable.h>
10#include <linux/nvmem-provider.h>
11#include <linux/platform_device.h>
12
13struct qoriq_efuse_priv {
14	void __iomem *base;
15};
16
17static int qoriq_efuse_read(void *context, unsigned int offset, void *val,
18			    size_t bytes)
19{
20	struct qoriq_efuse_priv *priv = context;
21
22	/* .stride = 4 so offset is guaranteed to be aligned */
23	__ioread32_copy(val, priv->base + offset, bytes / 4);
24
25	/* Ignore trailing bytes (there shouldn't be any) */
26
27	return 0;
28}
29
30static int qoriq_efuse_probe(struct platform_device *pdev)
31{
32	struct nvmem_config config = {
33		.dev = &pdev->dev,
34		.read_only = true,
35		.reg_read = qoriq_efuse_read,
36		.stride = sizeof(u32),
37		.word_size = sizeof(u32),
38		.name = "qoriq_efuse_read",
39		.id = NVMEM_DEVID_AUTO,
40		.root_only = true,
41	};
42	struct qoriq_efuse_priv *priv;
43	struct nvmem_device *nvmem;
44	struct resource *res;
45
46	priv = devm_kzalloc(config.dev, sizeof(*priv), GFP_KERNEL);
47	if (!priv)
48		return -ENOMEM;
49
50	priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
51	if (IS_ERR(priv->base))
52		return PTR_ERR(priv->base);
53
54	config.size = resource_size(res);
55	config.priv = priv;
56	nvmem = devm_nvmem_register(config.dev, &config);
57
58	return PTR_ERR_OR_ZERO(nvmem);
59}
60
61static const struct of_device_id qoriq_efuse_of_match[] = {
62	{ .compatible = "fsl,t1023-sfp", },
63	{/* sentinel */},
64};
65MODULE_DEVICE_TABLE(of, qoriq_efuse_of_match);
66
67static struct platform_driver qoriq_efuse_driver = {
68	.probe = qoriq_efuse_probe,
69	.driver = {
70		.name = "qoriq-efuse",
71		.of_match_table = qoriq_efuse_of_match,
72	},
73};
74module_platform_driver(qoriq_efuse_driver);
75
76MODULE_AUTHOR("Richard Alpe <richard.alpe@bit42.se>");
77MODULE_DESCRIPTION("NXP QorIQ Security Fuse Processor (SFP) Reader");
78MODULE_LICENSE("GPL");
79