1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 * Allwinner SoCs Reset Controller driver
 4 *
 5 * Copyright 2013 Maxime Ripard
 6 *
 7 * Maxime Ripard <maxime.ripard@free-electrons.com>
 8 */
 9
10#include <linux/err.h>
11#include <linux/io.h>
12#include <linux/init.h>
13#include <linux/of.h>
14#include <linux/of_address.h>
15#include <linux/platform_device.h>
16#include <linux/reset-controller.h>
17#include <linux/reset/sunxi.h>
18#include <linux/slab.h>
19#include <linux/spinlock.h>
20#include <linux/types.h>
21
22#include "reset-simple.h"
23
24static int sunxi_reset_init(struct device_node *np)
25{
26	struct reset_simple_data *data;
27	struct resource res;
28	resource_size_t size;
29	int ret;
30
31	data = kzalloc(sizeof(*data), GFP_KERNEL);
32	if (!data)
33		return -ENOMEM;
34
35	ret = of_address_to_resource(np, 0, &res);
36	if (ret)
37		goto err_alloc;
38
39	size = resource_size(&res);
40	if (!request_mem_region(res.start, size, np->name)) {
41		ret = -EBUSY;
42		goto err_alloc;
43	}
44
45	data->membase = ioremap(res.start, size);
46	if (!data->membase) {
47		ret = -ENOMEM;
48		goto err_alloc;
49	}
50
51	spin_lock_init(&data->lock);
52
53	data->rcdev.owner = THIS_MODULE;
54	data->rcdev.nr_resets = size * 8;
55	data->rcdev.ops = &reset_simple_ops;
56	data->rcdev.of_node = np;
57	data->active_low = true;
58
59	return reset_controller_register(&data->rcdev);
60
61err_alloc:
62	kfree(data);
63	return ret;
64};
65
66/*
67 * These are the reset controller we need to initialize early on in
68 * our system, before we can even think of using a regular device
69 * driver for it.
70 * The controllers that we can register through the regular device
71 * model are handled by the simple reset driver directly.
72 */
73static const struct of_device_id sunxi_early_reset_dt_ids[] __initconst = {
74	{ .compatible = "allwinner,sun6i-a31-ahb1-reset", },
75	{ /* sentinel */ },
76};
77
78void __init sun6i_reset_init(void)
79{
80	struct device_node *np;
81
82	for_each_matching_node(np, sunxi_early_reset_dt_ids)
83		sunxi_reset_init(np);
84}