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};
67