1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Layerscape SFP driver
4 *
5 * Copyright (c) 2022 Michael Walle <michael@walle.cc>
6 *
7 */
8
9 #include <linux/device.h>
10 #include <linux/io.h>
11 #include <linux/mod_devicetable.h>
12 #include <linux/module.h>
13 #include <linux/nvmem-provider.h>
14 #include <linux/platform_device.h>
15 #include <linux/property.h>
16 #include <linux/regmap.h>
17
18 #define LAYERSCAPE_SFP_OTP_OFFSET 0x0200
19
20 struct layerscape_sfp_priv {
21 struct regmap *regmap;
22 };
23
24 struct layerscape_sfp_data {
25 int size;
26 enum regmap_endian endian;
27 };
28
layerscape_sfp_read(void * context,unsigned int offset,void * val,size_t bytes)29 static int layerscape_sfp_read(void *context, unsigned int offset, void *val,
30 size_t bytes)
31 {
32 struct layerscape_sfp_priv *priv = context;
33
34 return regmap_bulk_read(priv->regmap,
35 LAYERSCAPE_SFP_OTP_OFFSET + offset, val,
36 bytes / 4);
37 }
38
39 static struct nvmem_config layerscape_sfp_nvmem_config = {
40 .name = "fsl-sfp",
41 .reg_read = layerscape_sfp_read,
42 .word_size = 4,
43 .stride = 4,
44 };
45
layerscape_sfp_probe(struct platform_device * pdev)46 static int layerscape_sfp_probe(struct platform_device *pdev)
47 {
48 const struct layerscape_sfp_data *data;
49 struct layerscape_sfp_priv *priv;
50 struct nvmem_device *nvmem;
51 struct regmap_config config = { 0 };
52 void __iomem *base;
53
54 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
55 if (!priv)
56 return -ENOMEM;
57
58 base = devm_platform_ioremap_resource(pdev, 0);
59 if (IS_ERR(base))
60 return PTR_ERR(base);
61
62 data = device_get_match_data(&pdev->dev);
63 config.reg_bits = 32;
64 config.reg_stride = 4;
65 config.val_bits = 32;
66 config.val_format_endian = data->endian;
67 config.max_register = LAYERSCAPE_SFP_OTP_OFFSET + data->size - 4;
68 priv->regmap = devm_regmap_init_mmio(&pdev->dev, base, &config);
69 if (IS_ERR(priv->regmap))
70 return PTR_ERR(priv->regmap);
71
72 layerscape_sfp_nvmem_config.size = data->size;
73 layerscape_sfp_nvmem_config.dev = &pdev->dev;
74 layerscape_sfp_nvmem_config.priv = priv;
75
76 nvmem = devm_nvmem_register(&pdev->dev, &layerscape_sfp_nvmem_config);
77
78 return PTR_ERR_OR_ZERO(nvmem);
79 }
80
81 static const struct layerscape_sfp_data ls1021a_data = {
82 .size = 0x88,
83 .endian = REGMAP_ENDIAN_BIG,
84 };
85
86 static const struct layerscape_sfp_data ls1028a_data = {
87 .size = 0x88,
88 .endian = REGMAP_ENDIAN_LITTLE,
89 };
90
91 static const struct of_device_id layerscape_sfp_dt_ids[] = {
92 { .compatible = "fsl,ls1021a-sfp", .data = &ls1021a_data },
93 { .compatible = "fsl,ls1028a-sfp", .data = &ls1028a_data },
94 {},
95 };
96 MODULE_DEVICE_TABLE(of, layerscape_sfp_dt_ids);
97
98 static struct platform_driver layerscape_sfp_driver = {
99 .probe = layerscape_sfp_probe,
100 .driver = {
101 .name = "layerscape_sfp",
102 .of_match_table = layerscape_sfp_dt_ids,
103 },
104 };
105 module_platform_driver(layerscape_sfp_driver);
106
107 MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
108 MODULE_DESCRIPTION("Layerscape Security Fuse Processor driver");
109 MODULE_LICENSE("GPL");
110