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-berlin.c (2855B)

      1/*
      2 * Copyright (C) 2014 Marvell Technology Group Ltd.
      3 *
      4 * Marvell Berlin reset driver
      5 *
      6 * Antoine Tenart <antoine.tenart@free-electrons.com>
      7 * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
      8 *
      9 * This file is licensed under the terms of the GNU General Public
     10 * License version 2. This program is licensed "as is" without any
     11 * warranty of any kind, whether express or implied.
     12 */
     13
     14#include <linux/delay.h>
     15#include <linux/io.h>
     16#include <linux/mfd/syscon.h>
     17#include <linux/module.h>
     18#include <linux/of.h>
     19#include <linux/of_address.h>
     20#include <linux/platform_device.h>
     21#include <linux/regmap.h>
     22#include <linux/reset-controller.h>
     23#include <linux/slab.h>
     24#include <linux/types.h>
     25
     26#define BERLIN_MAX_RESETS	32
     27
     28#define to_berlin_reset_priv(p)		\
     29	container_of((p), struct berlin_reset_priv, rcdev)
     30
     31struct berlin_reset_priv {
     32	struct regmap			*regmap;
     33	struct reset_controller_dev	rcdev;
     34};
     35
     36static int berlin_reset_reset(struct reset_controller_dev *rcdev,
     37			      unsigned long id)
     38{
     39	struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev);
     40	int offset = id >> 8;
     41	int mask = BIT(id & 0x1f);
     42
     43	regmap_write(priv->regmap, offset, mask);
     44
     45	/* let the reset be effective */
     46	udelay(10);
     47
     48	return 0;
     49}
     50
     51static const struct reset_control_ops berlin_reset_ops = {
     52	.reset	= berlin_reset_reset,
     53};
     54
     55static int berlin_reset_xlate(struct reset_controller_dev *rcdev,
     56			      const struct of_phandle_args *reset_spec)
     57{
     58	unsigned int offset, bit;
     59
     60	offset = reset_spec->args[0];
     61	bit = reset_spec->args[1];
     62
     63	if (bit >= BERLIN_MAX_RESETS)
     64		return -EINVAL;
     65
     66	return (offset << 8) | bit;
     67}
     68
     69static int berlin2_reset_probe(struct platform_device *pdev)
     70{
     71	struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
     72	struct berlin_reset_priv *priv;
     73
     74	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
     75	if (!priv)
     76		return -ENOMEM;
     77
     78	priv->regmap = syscon_node_to_regmap(parent_np);
     79	of_node_put(parent_np);
     80	if (IS_ERR(priv->regmap))
     81		return PTR_ERR(priv->regmap);
     82
     83	priv->rcdev.owner = THIS_MODULE;
     84	priv->rcdev.ops = &berlin_reset_ops;
     85	priv->rcdev.of_node = pdev->dev.of_node;
     86	priv->rcdev.of_reset_n_cells = 2;
     87	priv->rcdev.of_xlate = berlin_reset_xlate;
     88
     89	return reset_controller_register(&priv->rcdev);
     90}
     91
     92static const struct of_device_id berlin_reset_dt_match[] = {
     93	{ .compatible = "marvell,berlin2-reset" },
     94	{ },
     95};
     96MODULE_DEVICE_TABLE(of, berlin_reset_dt_match);
     97
     98static struct platform_driver berlin_reset_driver = {
     99	.probe	= berlin2_reset_probe,
    100	.driver	= {
    101		.name = "berlin2-reset",
    102		.of_match_table = berlin_reset_dt_match,
    103	},
    104};
    105module_platform_driver(berlin_reset_driver);
    106
    107MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
    108MODULE_AUTHOR("Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>");
    109MODULE_DESCRIPTION("Synaptics Berlin reset controller");
    110MODULE_LICENSE("GPL");