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
13 struct qoriq_efuse_priv {
14 void __iomem *base;
15 };
16
qoriq_efuse_read(void * context,unsigned int offset,void * val,size_t bytes)17 static 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
qoriq_efuse_probe(struct platform_device * pdev)30 static 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
61 static const struct of_device_id qoriq_efuse_of_match[] = {
62 { .compatible = "fsl,t1023-sfp", },
63 {/* sentinel */},
64 };
65 MODULE_DEVICE_TABLE(of, qoriq_efuse_of_match);
66
67 static 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 };
74 module_platform_driver(qoriq_efuse_driver);
75
76 MODULE_AUTHOR("Richard Alpe <richard.alpe@bit42.se>");
77 MODULE_DESCRIPTION("NXP QorIQ Security Fuse Processor (SFP) Reader");
78 MODULE_LICENSE("GPL");
79