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

reset-ath79.c (3361B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * AR71xx Reset Controller Driver
      4 * Author: Alban Bedel
      5 *
      6 * Copyright (C) 2015 Alban Bedel <albeu@free.fr>
      7 */
      8
      9#include <linux/io.h>
     10#include <linux/init.h>
     11#include <linux/mod_devicetable.h>
     12#include <linux/platform_device.h>
     13#include <linux/reset-controller.h>
     14#include <linux/reboot.h>
     15
     16struct ath79_reset {
     17	struct reset_controller_dev rcdev;
     18	struct notifier_block restart_nb;
     19	void __iomem *base;
     20	spinlock_t lock;
     21};
     22
     23#define FULL_CHIP_RESET 24
     24
     25static int ath79_reset_update(struct reset_controller_dev *rcdev,
     26			unsigned long id, bool assert)
     27{
     28	struct ath79_reset *ath79_reset =
     29		container_of(rcdev, struct ath79_reset, rcdev);
     30	unsigned long flags;
     31	u32 val;
     32
     33	spin_lock_irqsave(&ath79_reset->lock, flags);
     34	val = readl(ath79_reset->base);
     35	if (assert)
     36		val |= BIT(id);
     37	else
     38		val &= ~BIT(id);
     39	writel(val, ath79_reset->base);
     40	spin_unlock_irqrestore(&ath79_reset->lock, flags);
     41
     42	return 0;
     43}
     44
     45static int ath79_reset_assert(struct reset_controller_dev *rcdev,
     46			unsigned long id)
     47{
     48	return ath79_reset_update(rcdev, id, true);
     49}
     50
     51static int ath79_reset_deassert(struct reset_controller_dev *rcdev,
     52				unsigned long id)
     53{
     54	return ath79_reset_update(rcdev, id, false);
     55}
     56
     57static int ath79_reset_status(struct reset_controller_dev *rcdev,
     58			unsigned long id)
     59{
     60	struct ath79_reset *ath79_reset =
     61		container_of(rcdev, struct ath79_reset, rcdev);
     62	u32 val;
     63
     64	val = readl(ath79_reset->base);
     65
     66	return !!(val & BIT(id));
     67}
     68
     69static const struct reset_control_ops ath79_reset_ops = {
     70	.assert = ath79_reset_assert,
     71	.deassert = ath79_reset_deassert,
     72	.status = ath79_reset_status,
     73};
     74
     75static int ath79_reset_restart_handler(struct notifier_block *nb,
     76				unsigned long action, void *data)
     77{
     78	struct ath79_reset *ath79_reset =
     79		container_of(nb, struct ath79_reset, restart_nb);
     80
     81	ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET);
     82
     83	return NOTIFY_DONE;
     84}
     85
     86static int ath79_reset_probe(struct platform_device *pdev)
     87{
     88	struct ath79_reset *ath79_reset;
     89	struct resource *res;
     90	int err;
     91
     92	ath79_reset = devm_kzalloc(&pdev->dev,
     93				sizeof(*ath79_reset), GFP_KERNEL);
     94	if (!ath79_reset)
     95		return -ENOMEM;
     96
     97	platform_set_drvdata(pdev, ath79_reset);
     98
     99	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    100	ath79_reset->base = devm_ioremap_resource(&pdev->dev, res);
    101	if (IS_ERR(ath79_reset->base))
    102		return PTR_ERR(ath79_reset->base);
    103
    104	spin_lock_init(&ath79_reset->lock);
    105	ath79_reset->rcdev.ops = &ath79_reset_ops;
    106	ath79_reset->rcdev.owner = THIS_MODULE;
    107	ath79_reset->rcdev.of_node = pdev->dev.of_node;
    108	ath79_reset->rcdev.of_reset_n_cells = 1;
    109	ath79_reset->rcdev.nr_resets = 32;
    110
    111	err = devm_reset_controller_register(&pdev->dev, &ath79_reset->rcdev);
    112	if (err)
    113		return err;
    114
    115	ath79_reset->restart_nb.notifier_call = ath79_reset_restart_handler;
    116	ath79_reset->restart_nb.priority = 128;
    117
    118	err = register_restart_handler(&ath79_reset->restart_nb);
    119	if (err)
    120		dev_warn(&pdev->dev, "Failed to register restart handler\n");
    121
    122	return 0;
    123}
    124
    125static const struct of_device_id ath79_reset_dt_ids[] = {
    126	{ .compatible = "qca,ar7100-reset", },
    127	{ },
    128};
    129
    130static struct platform_driver ath79_reset_driver = {
    131	.probe	= ath79_reset_probe,
    132	.driver = {
    133		.name			= "ath79-reset",
    134		.of_match_table		= ath79_reset_dt_ids,
    135		.suppress_bind_attrs	= true,
    136	},
    137};
    138builtin_platform_driver(ath79_reset_driver);