2 * Amlogic Meson GX eFuse Driver
4 * Copyright (c) 2016 Endless Computers, Inc.
5 * Author: Carlo Caione <carlo@endlessm.com>
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.
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
17 #include <linux/clk.h>
18 #include <linux/module.h>
19 #include <linux/nvmem-provider.h>
21 #include <linux/platform_device.h>
23 #include <linux/firmware/meson/meson_sm.h>
25 static int meson_efuse_read(void *context, unsigned int offset,
26 void *val, size_t bytes)
28 return meson_sm_call_read((u8 *)val, bytes, SM_EFUSE_READ, offset,
32 static int meson_efuse_write(void *context, unsigned int offset,
33 void *val, size_t bytes)
35 return meson_sm_call_write((u8 *)val, bytes, SM_EFUSE_WRITE, offset,
39 static const struct of_device_id meson_efuse_match[] = {
40 { .compatible = "amlogic,meson-gxbb-efuse", },
43 MODULE_DEVICE_TABLE(of, meson_efuse_match);
45 static int meson_efuse_probe(struct platform_device *pdev)
47 struct device *dev = &pdev->dev;
48 struct nvmem_device *nvmem;
49 struct nvmem_config *econfig;
54 clk = devm_clk_get(dev, NULL);
57 if (ret != -EPROBE_DEFER)
58 dev_err(dev, "failed to get efuse gate");
62 ret = clk_prepare_enable(clk);
64 dev_err(dev, "failed to enable gate");
68 ret = devm_add_action_or_reset(dev,
69 (void(*)(void *))clk_disable_unprepare,
72 dev_err(dev, "failed to add disable callback");
76 if (meson_sm_call(SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) {
77 dev_err(dev, "failed to get max user");
81 econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL);
86 econfig->name = dev_name(dev);
88 econfig->word_size = 1;
89 econfig->reg_read = meson_efuse_read;
90 econfig->reg_write = meson_efuse_write;
93 nvmem = devm_nvmem_register(&pdev->dev, econfig);
95 return PTR_ERR_OR_ZERO(nvmem);
98 static struct platform_driver meson_efuse_driver = {
99 .probe = meson_efuse_probe,
101 .name = "meson-efuse",
102 .of_match_table = meson_efuse_match,
106 module_platform_driver(meson_efuse_driver);
108 MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
109 MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver");
110 MODULE_LICENSE("GPL v2");