cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

apple-efuses.c (1794B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Apple SoC eFuse driver
      4 *
      5 * Copyright (C) The Asahi Linux Contributors
      6 */
      7
      8#include <linux/io.h>
      9#include <linux/mod_devicetable.h>
     10#include <linux/module.h>
     11#include <linux/nvmem-provider.h>
     12#include <linux/platform_device.h>
     13
     14struct apple_efuses_priv {
     15	void __iomem *fuses;
     16};
     17
     18static int apple_efuses_read(void *context, unsigned int offset, void *val,
     19			     size_t bytes)
     20{
     21	struct apple_efuses_priv *priv = context;
     22	u32 *dst = val;
     23
     24	while (bytes >= sizeof(u32)) {
     25		*dst++ = readl_relaxed(priv->fuses + offset);
     26		bytes -= sizeof(u32);
     27		offset += sizeof(u32);
     28	}
     29
     30	return 0;
     31}
     32
     33static int apple_efuses_probe(struct platform_device *pdev)
     34{
     35	struct apple_efuses_priv *priv;
     36	struct resource *res;
     37	struct nvmem_config config = {
     38		.dev = &pdev->dev,
     39		.read_only = true,
     40		.reg_read = apple_efuses_read,
     41		.stride = sizeof(u32),
     42		.word_size = sizeof(u32),
     43		.name = "apple_efuses_nvmem",
     44		.id = NVMEM_DEVID_AUTO,
     45		.root_only = true,
     46	};
     47
     48	priv = devm_kzalloc(config.dev, sizeof(*priv), GFP_KERNEL);
     49	if (!priv)
     50		return -ENOMEM;
     51
     52	priv->fuses = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
     53	if (IS_ERR(priv->fuses))
     54		return PTR_ERR(priv->fuses);
     55
     56	config.priv = priv;
     57	config.size = resource_size(res);
     58
     59	return PTR_ERR_OR_ZERO(devm_nvmem_register(config.dev, &config));
     60}
     61
     62static const struct of_device_id apple_efuses_of_match[] = {
     63	{ .compatible = "apple,efuses", },
     64	{}
     65};
     66
     67MODULE_DEVICE_TABLE(of, apple_efuses_of_match);
     68
     69static struct platform_driver apple_efuses_driver = {
     70	.driver = {
     71		.name = "apple_efuses",
     72		.of_match_table = apple_efuses_of_match,
     73	},
     74	.probe = apple_efuses_probe,
     75};
     76
     77module_platform_driver(apple_efuses_driver);
     78
     79MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
     80MODULE_LICENSE("GPL");