1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2015 MediaTek Inc.
4 * Author: Andrew-CT Chen <andrew-ct.chen@mediatek.com>
5 */
6
7#include <linux/device.h>
8#include <linux/module.h>
9#include <linux/mod_devicetable.h>
10#include <linux/io.h>
11#include <linux/nvmem-provider.h>
12#include <linux/platform_device.h>
13#include <linux/property.h>
14
15struct mtk_efuse_pdata {
16 bool uses_post_processing;
17};
18
19struct mtk_efuse_priv {
20 void __iomem *base;
21};
22
23static int mtk_reg_read(void *context,
24 unsigned int reg, void *_val, size_t bytes)
25{
26 struct mtk_efuse_priv *priv = context;
27 void __iomem *addr = priv->base + reg;
28 u8 *val = _val;
29 int i;
30
31 for (i = 0; i < bytes; i++, val++)
32 *val = readb(addr: addr + i);
33
34 return 0;
35}
36
37static int mtk_efuse_gpu_speedbin_pp(void *context, const char *id, int index,
38 unsigned int offset, void *data, size_t bytes)
39{
40 u8 *val = data;
41
42 if (val[0] < 8)
43 val[0] = BIT(val[0]);
44
45 return 0;
46}
47
48static void mtk_efuse_fixup_dt_cell_info(struct nvmem_device *nvmem,
49 struct nvmem_cell_info *cell)
50{
51 size_t sz = strlen(cell->name);
52
53 /*
54 * On some SoCs, the GPU speedbin is not read as bitmask but as
55 * a number with range [0-7] (max 3 bits): post process to use
56 * it in OPP tables to describe supported-hw.
57 */
58 if (cell->nbits <= 3 &&
59 strncmp(cell->name, "gpu-speedbin", min(sz, strlen("gpu-speedbin"))) == 0)
60 cell->read_post_process = mtk_efuse_gpu_speedbin_pp;
61}
62
63static int mtk_efuse_probe(struct platform_device *pdev)
64{
65 struct device *dev = &pdev->dev;
66 struct resource *res;
67 struct nvmem_device *nvmem;
68 struct nvmem_config econfig = {};
69 struct mtk_efuse_priv *priv;
70 const struct mtk_efuse_pdata *pdata;
71 struct platform_device *socinfo;
72
73 priv = devm_kzalloc(dev, size: sizeof(*priv), GFP_KERNEL);
74 if (!priv)
75 return -ENOMEM;
76
77 priv->base = devm_platform_get_and_ioremap_resource(pdev, index: 0, res: &res);
78 if (IS_ERR(ptr: priv->base))
79 return PTR_ERR(ptr: priv->base);
80
81 pdata = device_get_match_data(dev);
82 econfig.add_legacy_fixed_of_cells = true;
83 econfig.stride = 1;
84 econfig.word_size = 1;
85 econfig.reg_read = mtk_reg_read;
86 econfig.size = resource_size(res);
87 econfig.priv = priv;
88 econfig.dev = dev;
89 if (pdata->uses_post_processing)
90 econfig.fixup_dt_cell_info = &mtk_efuse_fixup_dt_cell_info;
91 nvmem = devm_nvmem_register(dev, cfg: &econfig);
92 if (IS_ERR(ptr: nvmem))
93 return PTR_ERR(ptr: nvmem);
94
95 socinfo = platform_device_register_data(parent: &pdev->dev, name: "mtk-socinfo",
96 PLATFORM_DEVID_AUTO, NULL, size: 0);
97 if (IS_ERR(ptr: socinfo))
98 dev_info(dev, "MediaTek SoC Information will be unavailable\n");
99
100 platform_set_drvdata(pdev, data: socinfo);
101 return 0;
102}
103
104static const struct mtk_efuse_pdata mtk_mt8186_efuse_pdata = {
105 .uses_post_processing = true,
106};
107
108static const struct mtk_efuse_pdata mtk_efuse_pdata = {
109 .uses_post_processing = false,
110};
111
112static const struct of_device_id mtk_efuse_of_match[] = {
113 { .compatible = "mediatek,mt8173-efuse", .data = &mtk_efuse_pdata },
114 { .compatible = "mediatek,mt8186-efuse", .data = &mtk_mt8186_efuse_pdata },
115 { .compatible = "mediatek,efuse", .data = &mtk_efuse_pdata },
116 {/* sentinel */},
117};
118MODULE_DEVICE_TABLE(of, mtk_efuse_of_match);
119
120static void mtk_efuse_remove(struct platform_device *pdev)
121{
122 struct platform_device *socinfo = platform_get_drvdata(pdev);
123
124 if (!IS_ERR_OR_NULL(ptr: socinfo))
125 platform_device_unregister(socinfo);
126}
127
128static struct platform_driver mtk_efuse_driver = {
129 .probe = mtk_efuse_probe,
130 .remove_new = mtk_efuse_remove,
131 .driver = {
132 .name = "mediatek,efuse",
133 .of_match_table = mtk_efuse_of_match,
134 },
135};
136
137static int __init mtk_efuse_init(void)
138{
139 int ret;
140
141 ret = platform_driver_register(&mtk_efuse_driver);
142 if (ret) {
143 pr_err("Failed to register efuse driver\n");
144 return ret;
145 }
146
147 return 0;
148}
149
150static void __exit mtk_efuse_exit(void)
151{
152 return platform_driver_unregister(&mtk_efuse_driver);
153}
154
155subsys_initcall(mtk_efuse_init);
156module_exit(mtk_efuse_exit);
157
158MODULE_AUTHOR("Andrew-CT Chen <andrew-ct.chen@mediatek.com>");
159MODULE_DESCRIPTION("Mediatek EFUSE driver");
160MODULE_LICENSE("GPL v2");
161

source code of linux/drivers/nvmem/mtk-efuse.c