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b6b7ef93 SP |
1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* | |
3 | * Apple SoC eFuse driver | |
4 | * | |
5 | * Copyright (C) The Asahi Linux Contributors | |
6 | */ | |
7 | ||
8 | #include <linux/io.h> | |
9 | #include <linux/mod_devicetable.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/nvmem-provider.h> | |
12 | #include <linux/platform_device.h> | |
13 | ||
14 | struct apple_efuses_priv { | |
15 | void __iomem *fuses; | |
16 | }; | |
17 | ||
18 | static int apple_efuses_read(void *context, unsigned int offset, void *val, | |
19 | size_t bytes) | |
20 | { | |
21 | struct apple_efuses_priv *priv = context; | |
22 | u32 *dst = val; | |
23 | ||
24 | while (bytes >= sizeof(u32)) { | |
25 | *dst++ = readl_relaxed(priv->fuses + offset); | |
26 | bytes -= sizeof(u32); | |
27 | offset += sizeof(u32); | |
28 | } | |
29 | ||
30 | return 0; | |
31 | } | |
32 | ||
33 | static int apple_efuses_probe(struct platform_device *pdev) | |
34 | { | |
35 | struct apple_efuses_priv *priv; | |
36 | struct resource *res; | |
37 | struct nvmem_config config = { | |
38 | .dev = &pdev->dev, | |
2cc3b37f | 39 | .add_legacy_fixed_of_cells = true, |
b6b7ef93 SP |
40 | .read_only = true, |
41 | .reg_read = apple_efuses_read, | |
42 | .stride = sizeof(u32), | |
43 | .word_size = sizeof(u32), | |
44 | .name = "apple_efuses_nvmem", | |
45 | .id = NVMEM_DEVID_AUTO, | |
46 | .root_only = true, | |
47 | }; | |
48 | ||
49 | priv = devm_kzalloc(config.dev, sizeof(*priv), GFP_KERNEL); | |
50 | if (!priv) | |
51 | return -ENOMEM; | |
52 | ||
53 | priv->fuses = devm_platform_get_and_ioremap_resource(pdev, 0, &res); | |
54 | if (IS_ERR(priv->fuses)) | |
55 | return PTR_ERR(priv->fuses); | |
56 | ||
57 | config.priv = priv; | |
58 | config.size = resource_size(res); | |
59 | ||
60 | return PTR_ERR_OR_ZERO(devm_nvmem_register(config.dev, &config)); | |
61 | } | |
62 | ||
63 | static const struct of_device_id apple_efuses_of_match[] = { | |
64 | { .compatible = "apple,efuses", }, | |
65 | {} | |
66 | }; | |
67 | ||
68 | MODULE_DEVICE_TABLE(of, apple_efuses_of_match); | |
69 | ||
70 | static struct platform_driver apple_efuses_driver = { | |
71 | .driver = { | |
72 | .name = "apple_efuses", | |
73 | .of_match_table = apple_efuses_of_match, | |
74 | }, | |
75 | .probe = apple_efuses_probe, | |
76 | }; | |
77 | ||
78 | module_platform_driver(apple_efuses_driver); | |
79 | ||
80 | MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>"); | |
c553bad4 | 81 | MODULE_DESCRIPTION("Apple SoC eFuse driver"); |
b6b7ef93 | 82 | MODULE_LICENSE("GPL"); |