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 | |
16 | enum fuse_type { |
17 | FUSE_FSB = 1, |
18 | FUSE_ELE = 2, |
19 | FUSE_INVALID = -1 |
20 | }; |
21 | |
22 | struct ocotp_map_entry { |
23 | u32 start; /* start word */ |
24 | u32 num; /* num words */ |
25 | enum fuse_type type; |
26 | }; |
27 | |
28 | struct 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 | |
38 | struct 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 | |
46 | static 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 | |
64 | static 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 | |
108 | static 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 | |
143 | static 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 | |
158 | static const struct of_device_id imx_ele_ocotp_dt_ids[] = { |
159 | { .compatible = "fsl,imx93-ocotp" , .data = &imx93_ocotp_data, }, |
160 | {}, |
161 | }; |
162 | MODULE_DEVICE_TABLE(of, imx_ele_ocotp_dt_ids); |
163 | |
164 | static 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 | }; |
171 | module_platform_driver(imx_ele_ocotp_driver); |
172 | |
173 | MODULE_DESCRIPTION("i.MX OCOTP/ELE driver" ); |
174 | MODULE_AUTHOR("Peng Fan <peng.fan@nxp.com>" ); |
175 | MODULE_LICENSE("GPL" ); |
176 | |