tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Amlogic Meson GX eFuse Driver
4 *
5 * Copyright (c) 2016 Endless Computers, Inc.
6 * Author: Carlo Caione <carlo@endlessm.com>
7 */
8
9#include <linux/clk.h>
10#include <linux/module.h>
11#include <linux/nvmem-provider.h>
12#include <linux/of.h>
13#include <linux/platform_device.h>
14
15#include <linux/firmware/meson/meson_sm.h>
16
17static int meson_efuse_read(void *context, unsigned int offset,
18 void *val, size_t bytes)
19{
20 return meson_sm_call_read((u8 *)val, bytes, SM_EFUSE_READ, offset,
21 bytes, 0, 0, 0);
22}
23
24static int meson_efuse_write(void *context, unsigned int offset,
25 void *val, size_t bytes)
26{
27 return meson_sm_call_write((u8 *)val, bytes, SM_EFUSE_WRITE, offset,
28 bytes, 0, 0, 0);
29}
30
31static const struct of_device_id meson_efuse_match[] = {
32 { .compatible = "amlogic,meson-gxbb-efuse", },
33 { /* sentinel */ },
34};
35MODULE_DEVICE_TABLE(of, meson_efuse_match);
36
37static int meson_efuse_probe(struct platform_device *pdev)
38{
39 struct device *dev = &pdev->dev;
40 struct nvmem_device *nvmem;
41 struct nvmem_config *econfig;
42 struct clk *clk;
43 unsigned int size;
44 int ret;
45
46 clk = devm_clk_get(dev, NULL);
47 if (IS_ERR(clk)) {
48 ret = PTR_ERR(clk);
49 if (ret != -EPROBE_DEFER)
50 dev_err(dev, "failed to get efuse gate");
51 return ret;
52 }
53
54 ret = clk_prepare_enable(clk);
55 if (ret) {
56 dev_err(dev, "failed to enable gate");
57 return ret;
58 }
59
60 ret = devm_add_action_or_reset(dev,
61 (void(*)(void *))clk_disable_unprepare,
62 clk);
63 if (ret) {
64 dev_err(dev, "failed to add disable callback");
65 return ret;
66 }
67
68 if (meson_sm_call(SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) {
69 dev_err(dev, "failed to get max user");
70 return -EINVAL;
71 }
72
73 econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL);
74 if (!econfig)
75 return -ENOMEM;
76
77 econfig->dev = dev;
78 econfig->name = dev_name(dev);
79 econfig->stride = 1;
80 econfig->word_size = 1;
81 econfig->reg_read = meson_efuse_read;
82 econfig->reg_write = meson_efuse_write;
83 econfig->size = size;
84
85 nvmem = devm_nvmem_register(&pdev->dev, econfig);
86
87 return PTR_ERR_OR_ZERO(nvmem);
88}
89
90static struct platform_driver meson_efuse_driver = {
91 .probe = meson_efuse_probe,
92 .driver = {
93 .name = "meson-efuse",
94 .of_match_table = meson_efuse_match,
95 },
96};
97
98module_platform_driver(meson_efuse_driver);
99
100MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
101MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver");
102MODULE_LICENSE("GPL v2");