xref: /kernel/linux/linux-5.10/arch/mips/ralink/reset.c (revision 8c2ecf20) 
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *
4 * Copyright (C) 2008-2009 Gabor Juhos <juhosg@openwrt.org>
5 * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
6 * Copyright (C) 2013 John Crispin <john@phrozen.org>
7 */
8
9#include <linux/pm.h>
10#include <linux/io.h>
11#include <linux/of.h>
12#include <linux/delay.h>
13#include <linux/reset-controller.h>
14
15#include <asm/reboot.h>
16
17#include <asm/mach-ralink/ralink_regs.h>
18
19/* Reset Control */
20#define SYSC_REG_RESET_CTRL	0x034
21
22#define RSTCTL_RESET_PCI	BIT(26)
23#define RSTCTL_RESET_SYSTEM	BIT(0)
24
25static int ralink_assert_device(struct reset_controller_dev *rcdev,
26				unsigned long id)
27{
28	u32 val;
29
30	if (id < 8)
31		return -1;
32
33	val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
34	val |= BIT(id);
35	rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
36
37	return 0;
38}
39
40static int ralink_deassert_device(struct reset_controller_dev *rcdev,
41				  unsigned long id)
42{
43	u32 val;
44
45	if (id < 8)
46		return -1;
47
48	val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
49	val &= ~BIT(id);
50	rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
51
52	return 0;
53}
54
55static int ralink_reset_device(struct reset_controller_dev *rcdev,
56			       unsigned long id)
57{
58	ralink_assert_device(rcdev, id);
59	return ralink_deassert_device(rcdev, id);
60}
61
62static const struct reset_control_ops reset_ops = {
63	.reset = ralink_reset_device,
64	.assert = ralink_assert_device,
65	.deassert = ralink_deassert_device,
66};
67
68static struct reset_controller_dev reset_dev = {
69	.ops			= &reset_ops,
70	.owner			= THIS_MODULE,
71	.nr_resets		= 32,
72	.of_reset_n_cells	= 1,
73};
74
75void ralink_rst_init(void)
76{
77	reset_dev.of_node = of_find_compatible_node(NULL, NULL,
78						"ralink,rt2880-reset");
79	if (!reset_dev.of_node)
80		pr_err("Failed to find reset controller node");
81	else
82		reset_controller_register(&reset_dev);
83}
84
85static void ralink_restart(char *command)
86{
87	if (IS_ENABLED(CONFIG_PCI)) {
88		rt_sysc_m32(0, RSTCTL_RESET_PCI, SYSC_REG_RESET_CTRL);
89		mdelay(50);
90	}
91
92	local_irq_disable();
93	rt_sysc_w32(RSTCTL_RESET_SYSTEM, SYSC_REG_RESET_CTRL);
94	unreachable();
95}
96
97static int __init mips_reboot_setup(void)
98{
99	_machine_restart = ralink_restart;
100
101	return 0;
102}
103
104arch_initcall(mips_reboot_setup);
105