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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tps65086-restart.c (2464B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (C) 2021 Emil Renner Berthing
      4 */
      5
      6#include <linux/mfd/tps65086.h>
      7#include <linux/mod_devicetable.h>
      8#include <linux/module.h>
      9#include <linux/platform_device.h>
     10#include <linux/reboot.h>
     11
     12struct tps65086_restart {
     13	struct notifier_block handler;
     14	struct device *dev;
     15};
     16
     17static int tps65086_restart_notify(struct notifier_block *this,
     18				   unsigned long mode, void *cmd)
     19{
     20	struct tps65086_restart *tps65086_restart =
     21		container_of(this, struct tps65086_restart, handler);
     22	struct tps65086 *tps65086 = dev_get_drvdata(tps65086_restart->dev->parent);
     23	int ret;
     24
     25	ret = regmap_write(tps65086->regmap, TPS65086_FORCESHUTDN, 1);
     26	if (ret) {
     27		dev_err(tps65086_restart->dev, "%s: error writing to tps65086 pmic: %d\n",
     28			__func__, ret);
     29		return NOTIFY_DONE;
     30	}
     31
     32	/* give it a little time */
     33	mdelay(200);
     34
     35	WARN_ON(1);
     36
     37	return NOTIFY_DONE;
     38}
     39
     40static int tps65086_restart_probe(struct platform_device *pdev)
     41{
     42	struct tps65086_restart *tps65086_restart;
     43	int ret;
     44
     45	tps65086_restart = devm_kzalloc(&pdev->dev, sizeof(*tps65086_restart), GFP_KERNEL);
     46	if (!tps65086_restart)
     47		return -ENOMEM;
     48
     49	platform_set_drvdata(pdev, tps65086_restart);
     50
     51	tps65086_restart->handler.notifier_call = tps65086_restart_notify;
     52	tps65086_restart->handler.priority = 192;
     53	tps65086_restart->dev = &pdev->dev;
     54
     55	ret = register_restart_handler(&tps65086_restart->handler);
     56	if (ret) {
     57		dev_err(&pdev->dev, "%s: cannot register restart handler: %d\n",
     58			__func__, ret);
     59		return -ENODEV;
     60	}
     61
     62	return 0;
     63}
     64
     65static int tps65086_restart_remove(struct platform_device *pdev)
     66{
     67	struct tps65086_restart *tps65086_restart = platform_get_drvdata(pdev);
     68	int ret;
     69
     70	ret = unregister_restart_handler(&tps65086_restart->handler);
     71	if (ret) {
     72		dev_err(&pdev->dev, "%s: cannot unregister restart handler: %d\n",
     73			__func__, ret);
     74		return -ENODEV;
     75	}
     76
     77	return 0;
     78}
     79
     80static const struct platform_device_id tps65086_restart_id_table[] = {
     81	{ "tps65086-reset", },
     82	{ /* sentinel */ }
     83};
     84MODULE_DEVICE_TABLE(platform, tps65086_restart_id_table);
     85
     86static struct platform_driver tps65086_restart_driver = {
     87	.driver = {
     88		.name = "tps65086-restart",
     89	},
     90	.probe = tps65086_restart_probe,
     91	.remove = tps65086_restart_remove,
     92	.id_table = tps65086_restart_id_table,
     93};
     94module_platform_driver(tps65086_restart_driver);
     95
     96MODULE_AUTHOR("Emil Renner Berthing <kernel@esmil.dk>");
     97MODULE_DESCRIPTION("TPS65086 restart driver");
     98MODULE_LICENSE("GPL v2");