1/*
2 * Copyright (c) 2014 MediaTek Inc.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11 * GNU General Public License for more details.
12 */
13
14#include <linux/mfd/syscon.h>
15#include <linux/module.h>
16#include <linux/of.h>
17#include <linux/platform_device.h>
18#include <linux/regmap.h>
19#include <linux/reset-controller.h>
20#include <linux/slab.h>
21
22#include "clk-mtk.h"
23
24struct mtk_reset {
25	struct regmap *regmap;
26	int regofs;
27	struct reset_controller_dev rcdev;
28};
29
30static int mtk_reset_assert(struct reset_controller_dev *rcdev,
31			      unsigned long id)
32{
33	struct mtk_reset *data = container_of(rcdev, struct mtk_reset, rcdev);
34
35	return regmap_update_bits(data->regmap, data->regofs + ((id / 32) << 2),
36			BIT(id % 32), ~0);
37}
38
39static int mtk_reset_deassert(struct reset_controller_dev *rcdev,
40				unsigned long id)
41{
42	struct mtk_reset *data = container_of(rcdev, struct mtk_reset, rcdev);
43
44	return regmap_update_bits(data->regmap, data->regofs + ((id / 32) << 2),
45			BIT(id % 32), 0);
46}
47
48static int mtk_reset(struct reset_controller_dev *rcdev,
49			      unsigned long id)
50{
51	int ret;
52
53	ret = mtk_reset_assert(rcdev, id);
54	if (ret)
55		return ret;
56
57	return mtk_reset_deassert(rcdev, id);
58}
59
60static struct reset_control_ops mtk_reset_ops = {
61	.assert = mtk_reset_assert,
62	.deassert = mtk_reset_deassert,
63	.reset = mtk_reset,
64};
65
66void mtk_register_reset_controller(struct device_node *np,
67			unsigned int num_regs, int regofs)
68{
69	struct mtk_reset *data;
70	int ret;
71	struct regmap *regmap;
72
73	regmap = syscon_node_to_regmap(np);
74	if (IS_ERR(regmap)) {
75		pr_err("Cannot find regmap for %s: %ld\n", np->full_name,
76				PTR_ERR(regmap));
77		return;
78	}
79
80	data = kzalloc(sizeof(*data), GFP_KERNEL);
81	if (!data)
82		return;
83
84	data->regmap = regmap;
85	data->regofs = regofs;
86	data->rcdev.owner = THIS_MODULE;
87	data->rcdev.nr_resets = num_regs * 32;
88	data->rcdev.ops = &mtk_reset_ops;
89	data->rcdev.of_node = np;
90
91	ret = reset_controller_register(&data->rcdev);
92	if (ret) {
93		pr_err("could not register reset controller: %d\n", ret);
94		kfree(data);
95		return;
96	}
97}
98