tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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}