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
20struct layerscape_sfp_priv {
21	struct regmap *regmap;
22};
23
24struct layerscape_sfp_data {
25	int size;
26	enum regmap_endian endian;
27};
28
29static 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
39static 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
46static 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
81static const struct layerscape_sfp_data ls1021a_data = {
82	.size = 0x88,
83	.endian = REGMAP_ENDIAN_BIG,
84};
85
86static const struct layerscape_sfp_data ls1028a_data = {
87	.size = 0x88,
88	.endian = REGMAP_ENDIAN_LITTLE,
89};
90
91static 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};
96MODULE_DEVICE_TABLE(of, layerscape_sfp_dt_ids);
97
98static 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};
105module_platform_driver(layerscape_sfp_driver);
106
107MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
108MODULE_DESCRIPTION("Layerscape Security Fuse Processor driver");
109MODULE_LICENSE("GPL");
110