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/reset-simple.h> |
18 | #include <linux/reset/sunxi.h> |
19 | #include <linux/slab.h> |
20 | #include <linux/spinlock.h> |
21 | #include <linux/types.h> |
22 | |
23 | static int sunxi_reset_init(struct device_node *np) |
24 | { |
25 | struct reset_simple_data *data; |
26 | struct resource res; |
27 | resource_size_t size; |
28 | int ret; |
29 | |
30 | data = kzalloc(size: sizeof(*data), GFP_KERNEL); |
31 | if (!data) |
32 | return -ENOMEM; |
33 | |
34 | ret = of_address_to_resource(dev: np, index: 0, r: &res); |
35 | if (ret) |
36 | goto err_alloc; |
37 | |
38 | size = resource_size(res: &res); |
39 | if (!request_mem_region(res.start, size, np->name)) { |
40 | ret = -EBUSY; |
41 | goto err_alloc; |
42 | } |
43 | |
44 | data->membase = ioremap(offset: res.start, size); |
45 | if (!data->membase) { |
46 | ret = -ENOMEM; |
47 | goto err_alloc; |
48 | } |
49 | |
50 | spin_lock_init(&data->lock); |
51 | |
52 | data->rcdev.owner = THIS_MODULE; |
53 | data->rcdev.nr_resets = size * 8; |
54 | data->rcdev.ops = &reset_simple_ops; |
55 | data->rcdev.of_node = np; |
56 | data->active_low = true; |
57 | |
58 | return reset_controller_register(rcdev: &data->rcdev); |
59 | |
60 | err_alloc: |
61 | kfree(objp: data); |
62 | return ret; |
63 | }; |
64 | |
65 | /* |
66 | * These are the reset controller we need to initialize early on in |
67 | * our system, before we can even think of using a regular device |
68 | * driver for it. |
69 | * The controllers that we can register through the regular device |
70 | * model are handled by the simple reset driver directly. |
71 | */ |
72 | static const struct of_device_id sunxi_early_reset_dt_ids[] __initconst = { |
73 | { .compatible = "allwinner,sun6i-a31-ahb1-reset" , }, |
74 | { /* sentinel */ }, |
75 | }; |
76 | |
77 | void __init sun6i_reset_init(void) |
78 | { |
79 | struct device_node *np; |
80 | |
81 | for_each_matching_node(np, sunxi_early_reset_dt_ids) |
82 | sunxi_reset_init(np); |
83 | } |
84 | |