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");