1 /*
2 * Amlogic Meson GX eFuse Driver
3 *
4 * Copyright (c) 2016 Endless Computers, Inc.
5 * Author: Carlo Caione <carlo@endlessm.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of version 2 of the GNU General Public License as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * more details.
15 */
16
17 #include <linux/module.h>
18 #include <linux/nvmem-provider.h>
19 #include <linux/of.h>
20 #include <linux/platform_device.h>
21
22 #include <linux/firmware/meson/meson_sm.h>
23
meson_efuse_read(void * context,unsigned int offset,void * val,size_t bytes)24 static int meson_efuse_read(void *context, unsigned int offset,
25 void *val, size_t bytes)
26 {
27 return meson_sm_call_read((u8 *)val, bytes, SM_EFUSE_READ, offset,
28 bytes, 0, 0, 0);
29 }
30
meson_efuse_write(void * context,unsigned int offset,void * val,size_t bytes)31 static int meson_efuse_write(void *context, unsigned int offset,
32 void *val, size_t bytes)
33 {
34 return meson_sm_call_write((u8 *)val, bytes, SM_EFUSE_WRITE, offset,
35 bytes, 0, 0, 0);
36 }
37
38 static const struct of_device_id meson_efuse_match[] = {
39 { .compatible = "amlogic,meson-gxbb-efuse", },
40 { /* sentinel */ },
41 };
42 MODULE_DEVICE_TABLE(of, meson_efuse_match);
43
meson_efuse_probe(struct platform_device * pdev)44 static int meson_efuse_probe(struct platform_device *pdev)
45 {
46 struct device *dev = &pdev->dev;
47 struct nvmem_device *nvmem;
48 struct nvmem_config *econfig;
49 unsigned int size;
50
51 if (meson_sm_call(SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0)
52 return -EINVAL;
53
54 econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL);
55 if (!econfig)
56 return -ENOMEM;
57
58 econfig->dev = dev;
59 econfig->name = dev_name(dev);
60 econfig->stride = 1;
61 econfig->word_size = 1;
62 econfig->reg_read = meson_efuse_read;
63 econfig->reg_write = meson_efuse_write;
64 econfig->size = size;
65
66 nvmem = devm_nvmem_register(&pdev->dev, econfig);
67
68 return PTR_ERR_OR_ZERO(nvmem);
69 }
70
71 static struct platform_driver meson_efuse_driver = {
72 .probe = meson_efuse_probe,
73 .driver = {
74 .name = "meson-efuse",
75 .of_match_table = meson_efuse_match,
76 },
77 };
78
79 module_platform_driver(meson_efuse_driver);
80
81 MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
82 MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver");
83 MODULE_LICENSE("GPL v2");
84