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
15 struct uniphier_efuse_priv {
16 void __iomem *base;
17 };
18
uniphier_reg_read(void * context,unsigned int reg,void * _val,size_t bytes)19 static 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
uniphier_efuse_probe(struct platform_device * pdev)32 static 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 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
45 priv->base = devm_ioremap_resource(dev, res);
46 if (IS_ERR(priv->base))
47 return PTR_ERR(priv->base);
48
49 econfig.stride = 1;
50 econfig.word_size = 1;
51 econfig.read_only = true;
52 econfig.reg_read = uniphier_reg_read;
53 econfig.size = resource_size(res);
54 econfig.priv = priv;
55 econfig.dev = dev;
56 nvmem = devm_nvmem_register(dev, &econfig);
57
58 return PTR_ERR_OR_ZERO(nvmem);
59 }
60
61 static const struct of_device_id uniphier_efuse_of_match[] = {
62 { .compatible = "socionext,uniphier-efuse",},
63 {/* sentinel */},
64 };
65 MODULE_DEVICE_TABLE(of, uniphier_efuse_of_match);
66
67 static 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 };
74 module_platform_driver(uniphier_efuse_driver);
75
76 MODULE_AUTHOR("Keiji Hayashibara <hayashibara.keiji@socionext.com>");
77 MODULE_DESCRIPTION("UniPhier eFuse driver");
78 MODULE_LICENSE("GPL v2");
79