xref: /linux/drivers/nvmem/uniphier-efuse.c (revision b470fde8f77b56ff273c5527484b99499b894e16)
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/nvmem-provider.h>
12 #include <linux/platform_device.h>
13 
14 struct uniphier_efuse_priv {
15 	void __iomem *base;
16 };
17 
18 static int uniphier_reg_read(void *context,
19 			     unsigned int reg, void *_val, size_t bytes)
20 {
21 	struct uniphier_efuse_priv *priv = context;
22 	u8 *val = _val;
23 	int offs;
24 
25 	for (offs = 0; offs < bytes; offs += sizeof(u8))
26 		*val++ = readb(priv->base + reg + offs);
27 
28 	return 0;
29 }
30 
31 static int uniphier_efuse_probe(struct platform_device *pdev)
32 {
33 	struct device *dev = &pdev->dev;
34 	struct resource *res;
35 	struct nvmem_device *nvmem;
36 	struct nvmem_config econfig = {};
37 	struct uniphier_efuse_priv *priv;
38 
39 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
40 	if (!priv)
41 		return -ENOMEM;
42 
43 	priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
44 	if (IS_ERR(priv->base))
45 		return PTR_ERR(priv->base);
46 
47 	econfig.stride = 1;
48 	econfig.word_size = 1;
49 	econfig.read_only = true;
50 	econfig.reg_read = uniphier_reg_read;
51 	econfig.size = resource_size(res);
52 	econfig.priv = priv;
53 	econfig.dev = dev;
54 	econfig.add_legacy_fixed_of_cells = true;
55 	nvmem = devm_nvmem_register(dev, &econfig);
56 
57 	return PTR_ERR_OR_ZERO(nvmem);
58 }
59 
60 static const struct of_device_id uniphier_efuse_of_match[] = {
61 	{ .compatible = "socionext,uniphier-efuse",},
62 	{/* sentinel */},
63 };
64 MODULE_DEVICE_TABLE(of, uniphier_efuse_of_match);
65 
66 static struct platform_driver uniphier_efuse_driver = {
67 	.probe = uniphier_efuse_probe,
68 	.driver = {
69 		.name = "uniphier-efuse",
70 		.of_match_table = uniphier_efuse_of_match,
71 	},
72 };
73 module_platform_driver(uniphier_efuse_driver);
74 
75 MODULE_AUTHOR("Keiji Hayashibara <hayashibara.keiji@socionext.com>");
76 MODULE_DESCRIPTION("UniPhier eFuse driver");
77 MODULE_LICENSE("GPL v2");
78