xref: /openbmc/linux/arch/mips/ralink/reset.c (revision e3b9f1e8)
1 /*
2  * This program is free software; you can redistribute it and/or modify it
3  * under the terms of the GNU General Public License version 2 as published
4  * by the Free Software Foundation.
5  *
6  * Copyright (C) 2008-2009 Gabor Juhos <juhosg@openwrt.org>
7  * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
8  * Copyright (C) 2013 John Crispin <john@phrozen.org>
9  */
10 
11 #include <linux/pm.h>
12 #include <linux/io.h>
13 #include <linux/of.h>
14 #include <linux/delay.h>
15 #include <linux/reset-controller.h>
16 
17 #include <asm/reboot.h>
18 
19 #include <asm/mach-ralink/ralink_regs.h>
20 
21 /* Reset Control */
22 #define SYSC_REG_RESET_CTRL	0x034
23 
24 #define RSTCTL_RESET_PCI	BIT(26)
25 #define RSTCTL_RESET_SYSTEM	BIT(0)
26 
27 static int ralink_assert_device(struct reset_controller_dev *rcdev,
28 				unsigned long id)
29 {
30 	u32 val;
31 
32 	if (id < 8)
33 		return -1;
34 
35 	val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
36 	val |= BIT(id);
37 	rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
38 
39 	return 0;
40 }
41 
42 static int ralink_deassert_device(struct reset_controller_dev *rcdev,
43 				  unsigned long id)
44 {
45 	u32 val;
46 
47 	if (id < 8)
48 		return -1;
49 
50 	val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
51 	val &= ~BIT(id);
52 	rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
53 
54 	return 0;
55 }
56 
57 static int ralink_reset_device(struct reset_controller_dev *rcdev,
58 			       unsigned long id)
59 {
60 	ralink_assert_device(rcdev, id);
61 	return ralink_deassert_device(rcdev, id);
62 }
63 
64 static const struct reset_control_ops reset_ops = {
65 	.reset = ralink_reset_device,
66 	.assert = ralink_assert_device,
67 	.deassert = ralink_deassert_device,
68 };
69 
70 static struct reset_controller_dev reset_dev = {
71 	.ops			= &reset_ops,
72 	.owner			= THIS_MODULE,
73 	.nr_resets		= 32,
74 	.of_reset_n_cells	= 1,
75 };
76 
77 void ralink_rst_init(void)
78 {
79 	reset_dev.of_node = of_find_compatible_node(NULL, NULL,
80 						"ralink,rt2880-reset");
81 	if (!reset_dev.of_node)
82 		pr_err("Failed to find reset controller node");
83 	else
84 		reset_controller_register(&reset_dev);
85 }
86 
87 static void ralink_restart(char *command)
88 {
89 	if (IS_ENABLED(CONFIG_PCI)) {
90 		rt_sysc_m32(0, RSTCTL_RESET_PCI, SYSC_REG_RESET_CTRL);
91 		mdelay(50);
92 	}
93 
94 	local_irq_disable();
95 	rt_sysc_w32(RSTCTL_RESET_SYSTEM, SYSC_REG_RESET_CTRL);
96 	unreachable();
97 }
98 
99 static void ralink_halt(void)
100 {
101 	local_irq_disable();
102 	unreachable();
103 }
104 
105 static int __init mips_reboot_setup(void)
106 {
107 	_machine_restart = ralink_restart;
108 	_machine_halt = ralink_halt;
109 
110 	return 0;
111 }
112 
113 arch_initcall(mips_reboot_setup);
114