1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * i.MX9 OCOTP fusebox driver
4 *
5 * Copyright 2023 NXP
6 */
7
8#include <linux/device.h>
9#include <linux/io.h>
10#include <linux/module.h>
11#include <linux/nvmem-provider.h>
12#include <linux/of.h>
13#include <linux/platform_device.h>
14#include <linux/slab.h>
15
16enum fuse_type {
17 FUSE_FSB = 1,
18 FUSE_ELE = 2,
19 FUSE_INVALID = -1
20};
21
22struct ocotp_map_entry {
23 u32 start; /* start word */
24 u32 num; /* num words */
25 enum fuse_type type;
26};
27
28struct ocotp_devtype_data {
29 u32 reg_off;
30 char *name;
31 u32 size;
32 u32 num_entry;
33 u32 flag;
34 nvmem_reg_read_t reg_read;
35 struct ocotp_map_entry entry[];
36};
37
38struct imx_ocotp_priv {
39 struct device *dev;
40 void __iomem *base;
41 struct nvmem_config config;
42 struct mutex lock;
43 const struct ocotp_devtype_data *data;
44};
45
46static enum fuse_type imx_ocotp_fuse_type(void *context, u32 index)
47{
48 struct imx_ocotp_priv *priv = context;
49 const struct ocotp_devtype_data *data = priv->data;
50 u32 start, end;
51 int i;
52
53 for (i = 0; i < data->num_entry; i++) {
54 start = data->entry[i].start;
55 end = data->entry[i].start + data->entry[i].num;
56
57 if (index >= start && index < end)
58 return data->entry[i].type;
59 }
60
61 return FUSE_INVALID;
62}
63
64static int imx_ocotp_reg_read(void *context, unsigned int offset, void *val, size_t bytes)
65{
66 struct imx_ocotp_priv *priv = context;
67 void __iomem *reg = priv->base + priv->data->reg_off;
68 u32 count, index, num_bytes;
69 enum fuse_type type;
70 u32 *buf;
71 void *p;
72 int i;
73
74 index = offset;
75 num_bytes = round_up(bytes, 4);
76 count = num_bytes >> 2;
77
78 if (count > ((priv->data->size >> 2) - index))
79 count = (priv->data->size >> 2) - index;
80
81 p = kzalloc(size: num_bytes, GFP_KERNEL);
82 if (!p)
83 return -ENOMEM;
84
85 mutex_lock(&priv->lock);
86
87 buf = p;
88
89 for (i = index; i < (index + count); i++) {
90 type = imx_ocotp_fuse_type(context, index: i);
91 if (type == FUSE_INVALID || type == FUSE_ELE) {
92 *buf++ = 0;
93 continue;
94 }
95
96 *buf++ = readl_relaxed(reg + (i << 2));
97 }
98
99 memcpy(val, (u8 *)p, bytes);
100
101 mutex_unlock(lock: &priv->lock);
102
103 kfree(objp: p);
104
105 return 0;
106};
107
108static int imx_ele_ocotp_probe(struct platform_device *pdev)
109{
110 struct device *dev = &pdev->dev;
111 struct imx_ocotp_priv *priv;
112 struct nvmem_device *nvmem;
113
114 priv = devm_kzalloc(dev, size: sizeof(*priv), GFP_KERNEL);
115 if (!priv)
116 return -ENOMEM;
117
118 priv->data = of_device_get_match_data(dev);
119
120 priv->base = devm_platform_ioremap_resource(pdev, index: 0);
121 if (IS_ERR(ptr: priv->base))
122 return PTR_ERR(ptr: priv->base);
123
124 priv->config.dev = dev;
125 priv->config.name = "ELE-OCOTP";
126 priv->config.id = NVMEM_DEVID_AUTO;
127 priv->config.owner = THIS_MODULE;
128 priv->config.size = priv->data->size;
129 priv->config.reg_read = priv->data->reg_read;
130 priv->config.word_size = 4;
131 priv->config.stride = 1;
132 priv->config.priv = priv;
133 priv->config.read_only = true;
134 mutex_init(&priv->lock);
135
136 nvmem = devm_nvmem_register(dev, cfg: &priv->config);
137 if (IS_ERR(ptr: nvmem))
138 return PTR_ERR(ptr: nvmem);
139
140 return 0;
141}
142
143static const struct ocotp_devtype_data imx93_ocotp_data = {
144 .reg_off = 0x8000,
145 .reg_read = imx_ocotp_reg_read,
146 .size = 2048,
147 .num_entry = 6,
148 .entry = {
149 { 0, 52, FUSE_FSB },
150 { 63, 1, FUSE_ELE},
151 { 128, 16, FUSE_ELE },
152 { 182, 1, FUSE_ELE },
153 { 188, 1, FUSE_ELE },
154 { 312, 200, FUSE_FSB }
155 },
156};
157
158static const struct of_device_id imx_ele_ocotp_dt_ids[] = {
159 { .compatible = "fsl,imx93-ocotp", .data = &imx93_ocotp_data, },
160 {},
161};
162MODULE_DEVICE_TABLE(of, imx_ele_ocotp_dt_ids);
163
164static struct platform_driver imx_ele_ocotp_driver = {
165 .driver = {
166 .name = "imx_ele_ocotp",
167 .of_match_table = imx_ele_ocotp_dt_ids,
168 },
169 .probe = imx_ele_ocotp_probe,
170};
171module_platform_driver(imx_ele_ocotp_driver);
172
173MODULE_DESCRIPTION("i.MX OCOTP/ELE driver");
174MODULE_AUTHOR("Peng Fan <peng.fan@nxp.com>");
175MODULE_LICENSE("GPL");
176

source code of linux/drivers/nvmem/imx-ocotp-ele.c