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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reset-brcmstb.c (3412B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Broadcom STB generic reset controller for SW_INIT style reset controller
      4 *
      5 * Author: Florian Fainelli <f.fainelli@gmail.com>
      6 * Copyright (C) 2018 Broadcom
      7 */
      8#include <linux/delay.h>
      9#include <linux/device.h>
     10#include <linux/io.h>
     11#include <linux/module.h>
     12#include <linux/of.h>
     13#include <linux/platform_device.h>
     14#include <linux/reset-controller.h>
     15#include <linux/types.h>
     16
     17struct brcmstb_reset {
     18	void __iomem *base;
     19	struct reset_controller_dev rcdev;
     20};
     21
     22#define SW_INIT_SET		0x00
     23#define SW_INIT_CLEAR		0x04
     24#define SW_INIT_STATUS		0x08
     25
     26#define SW_INIT_BIT(id)		BIT((id) & 0x1f)
     27#define SW_INIT_BANK(id)	((id) >> 5)
     28
     29/* A full bank contains extra registers that we are not utilizing but still
     30 * qualify as a single bank.
     31 */
     32#define SW_INIT_BANK_SIZE	0x18
     33
     34static inline
     35struct brcmstb_reset *to_brcmstb(struct reset_controller_dev *rcdev)
     36{
     37	return container_of(rcdev, struct brcmstb_reset, rcdev);
     38}
     39
     40static int brcmstb_reset_assert(struct reset_controller_dev *rcdev,
     41				unsigned long id)
     42{
     43	unsigned int off = SW_INIT_BANK(id) * SW_INIT_BANK_SIZE;
     44	struct brcmstb_reset *priv = to_brcmstb(rcdev);
     45
     46	writel_relaxed(SW_INIT_BIT(id), priv->base + off + SW_INIT_SET);
     47
     48	return 0;
     49}
     50
     51static int brcmstb_reset_deassert(struct reset_controller_dev *rcdev,
     52				  unsigned long id)
     53{
     54	unsigned int off = SW_INIT_BANK(id) * SW_INIT_BANK_SIZE;
     55	struct brcmstb_reset *priv = to_brcmstb(rcdev);
     56
     57	writel_relaxed(SW_INIT_BIT(id), priv->base + off + SW_INIT_CLEAR);
     58	/* Maximum reset delay after de-asserting a line and seeing block
     59	 * operation is typically 14us for the worst case, build some slack
     60	 * here.
     61	 */
     62	usleep_range(100, 200);
     63
     64	return 0;
     65}
     66
     67static int brcmstb_reset_status(struct reset_controller_dev *rcdev,
     68				unsigned long id)
     69{
     70	unsigned int off = SW_INIT_BANK(id) * SW_INIT_BANK_SIZE;
     71	struct brcmstb_reset *priv = to_brcmstb(rcdev);
     72
     73	return readl_relaxed(priv->base + off + SW_INIT_STATUS) &
     74			     SW_INIT_BIT(id);
     75}
     76
     77static const struct reset_control_ops brcmstb_reset_ops = {
     78	.assert	= brcmstb_reset_assert,
     79	.deassert = brcmstb_reset_deassert,
     80	.status = brcmstb_reset_status,
     81};
     82
     83static int brcmstb_reset_probe(struct platform_device *pdev)
     84{
     85	struct device *kdev = &pdev->dev;
     86	struct brcmstb_reset *priv;
     87	struct resource *res;
     88
     89	priv = devm_kzalloc(kdev, sizeof(*priv), GFP_KERNEL);
     90	if (!priv)
     91		return -ENOMEM;
     92
     93	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
     94	priv->base = devm_ioremap_resource(kdev, res);
     95	if (IS_ERR(priv->base))
     96		return PTR_ERR(priv->base);
     97
     98	dev_set_drvdata(kdev, priv);
     99
    100	priv->rcdev.owner = THIS_MODULE;
    101	priv->rcdev.nr_resets = DIV_ROUND_DOWN_ULL(resource_size(res),
    102						   SW_INIT_BANK_SIZE) * 32;
    103	priv->rcdev.ops = &brcmstb_reset_ops;
    104	priv->rcdev.of_node = kdev->of_node;
    105	/* Use defaults: 1 cell and simple xlate function */
    106
    107	return devm_reset_controller_register(kdev, &priv->rcdev);
    108}
    109
    110static const struct of_device_id brcmstb_reset_of_match[] = {
    111	{ .compatible = "brcm,brcmstb-reset" },
    112	{ /* sentinel */ }
    113};
    114MODULE_DEVICE_TABLE(of, brcmstb_reset_of_match);
    115
    116static struct platform_driver brcmstb_reset_driver = {
    117	.probe	= brcmstb_reset_probe,
    118	.driver	= {
    119		.name = "brcmstb-reset",
    120		.of_match_table = brcmstb_reset_of_match,
    121	},
    122};
    123module_platform_driver(brcmstb_reset_driver);
    124
    125MODULE_AUTHOR("Broadcom");
    126MODULE_DESCRIPTION("Broadcom STB reset controller");
    127MODULE_LICENSE("GPL");