cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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layerscape-sfp.c (2769B)

      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");