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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owl-reset.c (1664B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2//
      3// Actions Semi Owl SoCs Reset Management Unit driver
      4//
      5// Copyright (c) 2018 Linaro Ltd.
      6// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
      7
      8#include <linux/delay.h>
      9#include <linux/regmap.h>
     10#include <linux/reset-controller.h>
     11
     12#include "owl-reset.h"
     13
     14static int owl_reset_assert(struct reset_controller_dev *rcdev,
     15			    unsigned long id)
     16{
     17	struct owl_reset *reset = to_owl_reset(rcdev);
     18	const struct owl_reset_map *map = &reset->reset_map[id];
     19
     20	return regmap_update_bits(reset->regmap, map->reg, map->bit, 0);
     21}
     22
     23static int owl_reset_deassert(struct reset_controller_dev *rcdev,
     24			      unsigned long id)
     25{
     26	struct owl_reset *reset = to_owl_reset(rcdev);
     27	const struct owl_reset_map *map = &reset->reset_map[id];
     28
     29	return regmap_update_bits(reset->regmap, map->reg, map->bit, map->bit);
     30}
     31
     32static int owl_reset_reset(struct reset_controller_dev *rcdev,
     33			   unsigned long id)
     34{
     35	owl_reset_assert(rcdev, id);
     36	udelay(1);
     37	owl_reset_deassert(rcdev, id);
     38
     39	return 0;
     40}
     41
     42static int owl_reset_status(struct reset_controller_dev *rcdev,
     43			    unsigned long id)
     44{
     45	struct owl_reset *reset = to_owl_reset(rcdev);
     46	const struct owl_reset_map *map = &reset->reset_map[id];
     47	u32 reg;
     48	int ret;
     49
     50	ret = regmap_read(reset->regmap, map->reg, &reg);
     51	if (ret)
     52		return ret;
     53
     54	/*
     55	 * The reset control API expects 0 if reset is not asserted,
     56	 * which is the opposite of what our hardware uses.
     57	 */
     58	return !(map->bit & reg);
     59}
     60
     61const struct reset_control_ops owl_reset_ops = {
     62	.assert		= owl_reset_assert,
     63	.deassert	= owl_reset_deassert,
     64	.reset		= owl_reset_reset,
     65	.status		= owl_reset_status,
     66};