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-k210.c (3034B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Copyright (c) 2020 Western Digital Corporation or its affiliates.
      4 */
      5#include <linux/of.h>
      6#include <linux/of_device.h>
      7#include <linux/platform_device.h>
      8#include <linux/reset-controller.h>
      9#include <linux/delay.h>
     10#include <linux/mfd/syscon.h>
     11#include <linux/regmap.h>
     12#include <soc/canaan/k210-sysctl.h>
     13
     14#include <dt-bindings/reset/k210-rst.h>
     15
     16#define K210_RST_MASK	0x27FFFFFF
     17
     18struct k210_rst {
     19	struct regmap *map;
     20	struct reset_controller_dev rcdev;
     21};
     22
     23static inline struct k210_rst *
     24to_k210_rst(struct reset_controller_dev *rcdev)
     25{
     26	return container_of(rcdev, struct k210_rst, rcdev);
     27}
     28
     29static inline int k210_rst_assert(struct reset_controller_dev *rcdev,
     30				  unsigned long id)
     31{
     32	struct k210_rst *ksr = to_k210_rst(rcdev);
     33
     34	return regmap_update_bits(ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), 1);
     35}
     36
     37static inline int k210_rst_deassert(struct reset_controller_dev *rcdev,
     38				    unsigned long id)
     39{
     40	struct k210_rst *ksr = to_k210_rst(rcdev);
     41
     42	return regmap_update_bits(ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), 0);
     43}
     44
     45static int k210_rst_reset(struct reset_controller_dev *rcdev,
     46			  unsigned long id)
     47{
     48	int ret;
     49
     50	ret = k210_rst_assert(rcdev, id);
     51	if (ret == 0) {
     52		udelay(10);
     53		ret = k210_rst_deassert(rcdev, id);
     54	}
     55
     56	return ret;
     57}
     58
     59static int k210_rst_status(struct reset_controller_dev *rcdev,
     60			   unsigned long id)
     61{
     62	struct k210_rst *ksr = to_k210_rst(rcdev);
     63	u32 reg, bit = BIT(id);
     64	int ret;
     65
     66	ret = regmap_read(ksr->map, K210_SYSCTL_PERI_RESET, &reg);
     67	if (ret)
     68		return ret;
     69
     70	return reg & bit;
     71}
     72
     73static int k210_rst_xlate(struct reset_controller_dev *rcdev,
     74			  const struct of_phandle_args *reset_spec)
     75{
     76	unsigned long id = reset_spec->args[0];
     77
     78	if (!(BIT(id) & K210_RST_MASK))
     79		return -EINVAL;
     80
     81	return id;
     82}
     83
     84static const struct reset_control_ops k210_rst_ops = {
     85	.assert		= k210_rst_assert,
     86	.deassert	= k210_rst_deassert,
     87	.reset		= k210_rst_reset,
     88	.status		= k210_rst_status,
     89};
     90
     91static int k210_rst_probe(struct platform_device *pdev)
     92{
     93	struct device *dev = &pdev->dev;
     94	struct device_node *parent_np = of_get_parent(dev->of_node);
     95	struct k210_rst *ksr;
     96
     97	dev_info(dev, "K210 reset controller\n");
     98
     99	ksr = devm_kzalloc(dev, sizeof(*ksr), GFP_KERNEL);
    100	if (!ksr)
    101		return -ENOMEM;
    102
    103	ksr->map = syscon_node_to_regmap(parent_np);
    104	of_node_put(parent_np);
    105	if (IS_ERR(ksr->map))
    106		return PTR_ERR(ksr->map);
    107
    108	ksr->rcdev.owner = THIS_MODULE;
    109	ksr->rcdev.dev = dev;
    110	ksr->rcdev.of_node = dev->of_node;
    111	ksr->rcdev.ops = &k210_rst_ops;
    112	ksr->rcdev.nr_resets = fls(K210_RST_MASK);
    113	ksr->rcdev.of_reset_n_cells = 1;
    114	ksr->rcdev.of_xlate = k210_rst_xlate;
    115
    116	return devm_reset_controller_register(dev, &ksr->rcdev);
    117}
    118
    119static const struct of_device_id k210_rst_dt_ids[] = {
    120	{ .compatible = "canaan,k210-rst" },
    121	{ /* sentinel */ },
    122};
    123
    124static struct platform_driver k210_rst_driver = {
    125	.probe	= k210_rst_probe,
    126	.driver = {
    127		.name		= "k210-rst",
    128		.of_match_table	= k210_rst_dt_ids,
    129	},
    130};
    131builtin_platform_driver(k210_rst_driver);