1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Allwinner SoCs Reset Controller driver
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright 2013 Maxime Ripard
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Maxime Ripard <maxime.ripard@free-electrons.com>
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/err.h>
11*4882a593Smuzhiyun #include <linux/io.h>
12*4882a593Smuzhiyun #include <linux/init.h>
13*4882a593Smuzhiyun #include <linux/of.h>
14*4882a593Smuzhiyun #include <linux/of_address.h>
15*4882a593Smuzhiyun #include <linux/platform_device.h>
16*4882a593Smuzhiyun #include <linux/reset-controller.h>
17*4882a593Smuzhiyun #include <linux/reset/reset-simple.h>
18*4882a593Smuzhiyun #include <linux/reset/sunxi.h>
19*4882a593Smuzhiyun #include <linux/slab.h>
20*4882a593Smuzhiyun #include <linux/spinlock.h>
21*4882a593Smuzhiyun #include <linux/types.h>
22*4882a593Smuzhiyun
sunxi_reset_init(struct device_node * np)23*4882a593Smuzhiyun static int sunxi_reset_init(struct device_node *np)
24*4882a593Smuzhiyun {
25*4882a593Smuzhiyun struct reset_simple_data *data;
26*4882a593Smuzhiyun struct resource res;
27*4882a593Smuzhiyun resource_size_t size;
28*4882a593Smuzhiyun int ret;
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun data = kzalloc(sizeof(*data), GFP_KERNEL);
31*4882a593Smuzhiyun if (!data)
32*4882a593Smuzhiyun return -ENOMEM;
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun ret = of_address_to_resource(np, 0, &res);
35*4882a593Smuzhiyun if (ret)
36*4882a593Smuzhiyun goto err_alloc;
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun size = resource_size(&res);
39*4882a593Smuzhiyun if (!request_mem_region(res.start, size, np->name)) {
40*4882a593Smuzhiyun ret = -EBUSY;
41*4882a593Smuzhiyun goto err_alloc;
42*4882a593Smuzhiyun }
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun data->membase = ioremap(res.start, size);
45*4882a593Smuzhiyun if (!data->membase) {
46*4882a593Smuzhiyun ret = -ENOMEM;
47*4882a593Smuzhiyun goto err_alloc;
48*4882a593Smuzhiyun }
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun spin_lock_init(&data->lock);
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun data->rcdev.owner = THIS_MODULE;
53*4882a593Smuzhiyun data->rcdev.nr_resets = size * 8;
54*4882a593Smuzhiyun data->rcdev.ops = &reset_simple_ops;
55*4882a593Smuzhiyun data->rcdev.of_node = np;
56*4882a593Smuzhiyun data->active_low = true;
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun return reset_controller_register(&data->rcdev);
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun err_alloc:
61*4882a593Smuzhiyun kfree(data);
62*4882a593Smuzhiyun return ret;
63*4882a593Smuzhiyun };
64*4882a593Smuzhiyun
65*4882a593Smuzhiyun /*
66*4882a593Smuzhiyun * These are the reset controller we need to initialize early on in
67*4882a593Smuzhiyun * our system, before we can even think of using a regular device
68*4882a593Smuzhiyun * driver for it.
69*4882a593Smuzhiyun * The controllers that we can register through the regular device
70*4882a593Smuzhiyun * model are handled by the simple reset driver directly.
71*4882a593Smuzhiyun */
72*4882a593Smuzhiyun static const struct of_device_id sunxi_early_reset_dt_ids[] __initconst = {
73*4882a593Smuzhiyun { .compatible = "allwinner,sun6i-a31-ahb1-reset", },
74*4882a593Smuzhiyun { /* sentinel */ },
75*4882a593Smuzhiyun };
76*4882a593Smuzhiyun
sun6i_reset_init(void)77*4882a593Smuzhiyun void __init sun6i_reset_init(void)
78*4882a593Smuzhiyun {
79*4882a593Smuzhiyun struct device_node *np;
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun for_each_matching_node(np, sunxi_early_reset_dt_ids)
82*4882a593Smuzhiyun sunxi_reset_init(np);
83*4882a593Smuzhiyun }
84