1 // SPDX-License-Identifier: GPL-2.0-only
3 * Amlogic Meson GX eFuse Driver
5 * Copyright (c) 2016 Endless Computers, Inc.
6 * Author: Carlo Caione <carlo@endlessm.com>
10 #include <linux/module.h>
11 #include <linux/nvmem-provider.h>
13 #include <linux/platform_device.h>
15 #include <linux/firmware/meson/meson_sm.h>
17 static int meson_efuse_read(void *context, unsigned int offset,
18 void *val, size_t bytes)
20 struct meson_sm_firmware *fw = context;
22 return meson_sm_call_read(fw, (u8 *)val, bytes, SM_EFUSE_READ, offset,
26 static int meson_efuse_write(void *context, unsigned int offset,
27 void *val, size_t bytes)
29 struct meson_sm_firmware *fw = context;
31 return meson_sm_call_write(fw, (u8 *)val, bytes, SM_EFUSE_WRITE, offset,
35 static const struct of_device_id meson_efuse_match[] = {
36 { .compatible = "amlogic,meson-gxbb-efuse", },
39 MODULE_DEVICE_TABLE(of, meson_efuse_match);
41 static int meson_efuse_probe(struct platform_device *pdev)
43 struct device *dev = &pdev->dev;
44 struct meson_sm_firmware *fw;
45 struct device_node *sm_np;
46 struct nvmem_device *nvmem;
47 struct nvmem_config *econfig;
51 sm_np = of_parse_phandle(pdev->dev.of_node, "secure-monitor", 0);
53 dev_err(&pdev->dev, "no secure-monitor node\n");
57 fw = meson_sm_get(sm_np);
62 clk = devm_clk_get_enabled(dev, NULL);
64 return dev_err_probe(dev, PTR_ERR(clk), "failed to get efuse gate");
66 if (meson_sm_call(fw, SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) {
67 dev_err(dev, "failed to get max user");
71 econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL);
76 econfig->name = dev_name(dev);
78 econfig->word_size = 1;
79 econfig->reg_read = meson_efuse_read;
80 econfig->reg_write = meson_efuse_write;
84 nvmem = devm_nvmem_register(&pdev->dev, econfig);
86 return PTR_ERR_OR_ZERO(nvmem);
89 static struct platform_driver meson_efuse_driver = {
90 .probe = meson_efuse_probe,
92 .name = "meson-efuse",
93 .of_match_table = meson_efuse_match,
97 module_platform_driver(meson_efuse_driver);
99 MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
100 MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver");
101 MODULE_LICENSE("GPL v2");