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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nvmem-reboot-mode.c (1966B)

      1// SPDX-License-Identifier: GPL-2.0+
      2/*
      3 * Copyright (c) Vaisala Oyj. All rights reserved.
      4 */
      5
      6#include <linux/init.h>
      7#include <linux/module.h>
      8#include <linux/kernel.h>
      9#include <linux/of.h>
     10#include <linux/nvmem-consumer.h>
     11#include <linux/platform_device.h>
     12#include <linux/reboot-mode.h>
     13
     14struct nvmem_reboot_mode {
     15	struct reboot_mode_driver reboot;
     16	struct nvmem_cell *cell;
     17};
     18
     19static int nvmem_reboot_mode_write(struct reboot_mode_driver *reboot,
     20				    unsigned int magic)
     21{
     22	int ret;
     23	struct nvmem_reboot_mode *nvmem_rbm;
     24
     25	nvmem_rbm = container_of(reboot, struct nvmem_reboot_mode, reboot);
     26
     27	ret = nvmem_cell_write(nvmem_rbm->cell, &magic, sizeof(magic));
     28	if (ret < 0)
     29		dev_err(reboot->dev, "update reboot mode bits failed\n");
     30
     31	return ret;
     32}
     33
     34static int nvmem_reboot_mode_probe(struct platform_device *pdev)
     35{
     36	int ret;
     37	struct nvmem_reboot_mode *nvmem_rbm;
     38
     39	nvmem_rbm = devm_kzalloc(&pdev->dev, sizeof(*nvmem_rbm), GFP_KERNEL);
     40	if (!nvmem_rbm)
     41		return -ENOMEM;
     42
     43	nvmem_rbm->reboot.dev = &pdev->dev;
     44	nvmem_rbm->reboot.write = nvmem_reboot_mode_write;
     45
     46	nvmem_rbm->cell = devm_nvmem_cell_get(&pdev->dev, "reboot-mode");
     47	if (IS_ERR(nvmem_rbm->cell)) {
     48		dev_err(&pdev->dev, "failed to get the nvmem cell reboot-mode\n");
     49		return PTR_ERR(nvmem_rbm->cell);
     50	}
     51
     52	ret = devm_reboot_mode_register(&pdev->dev, &nvmem_rbm->reboot);
     53	if (ret)
     54		dev_err(&pdev->dev, "can't register reboot mode\n");
     55
     56	return ret;
     57}
     58
     59static const struct of_device_id nvmem_reboot_mode_of_match[] = {
     60	{ .compatible = "nvmem-reboot-mode" },
     61	{}
     62};
     63MODULE_DEVICE_TABLE(of, nvmem_reboot_mode_of_match);
     64
     65static struct platform_driver nvmem_reboot_mode_driver = {
     66	.probe = nvmem_reboot_mode_probe,
     67	.driver = {
     68		.name = "nvmem-reboot-mode",
     69		.of_match_table = nvmem_reboot_mode_of_match,
     70	},
     71};
     72module_platform_driver(nvmem_reboot_mode_driver);
     73
     74MODULE_AUTHOR("Nandor Han <nandor.han@vaisala.com>");
     75MODULE_DESCRIPTION("NVMEM reboot mode driver");
     76MODULE_LICENSE("GPL");