xref: /openbmc/linux/arch/mips/ralink/reset.c (revision 4f3db074)
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 <blogic@openwrt.org>
9  */
10 
11 #include <linux/pm.h>
12 #include <linux/io.h>
13 #include <linux/of.h>
14 #include <linux/reset-controller.h>
15 
16 #include <asm/reboot.h>
17 
18 #include <asm/mach-ralink/ralink_regs.h>
19 
20 /* Reset Control */
21 #define SYSC_REG_RESET_CTRL     0x034
22 #define RSTCTL_RESET_SYSTEM     BIT(0)
23 
24 static int ralink_assert_device(struct reset_controller_dev *rcdev,
25 				unsigned long id)
26 {
27 	u32 val;
28 
29 	if (id < 8)
30 		return -1;
31 
32 	val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
33 	val |= BIT(id);
34 	rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
35 
36 	return 0;
37 }
38 
39 static int ralink_deassert_device(struct reset_controller_dev *rcdev,
40 				  unsigned long id)
41 {
42 	u32 val;
43 
44 	if (id < 8)
45 		return -1;
46 
47 	val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
48 	val &= ~BIT(id);
49 	rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
50 
51 	return 0;
52 }
53 
54 static int ralink_reset_device(struct reset_controller_dev *rcdev,
55 			       unsigned long id)
56 {
57 	ralink_assert_device(rcdev, id);
58 	return ralink_deassert_device(rcdev, id);
59 }
60 
61 static struct reset_control_ops reset_ops = {
62 	.reset = ralink_reset_device,
63 	.assert = ralink_assert_device,
64 	.deassert = ralink_deassert_device,
65 };
66 
67 static struct reset_controller_dev reset_dev = {
68 	.ops			= &reset_ops,
69 	.owner			= THIS_MODULE,
70 	.nr_resets		= 32,
71 	.of_reset_n_cells	= 1,
72 };
73 
74 void ralink_rst_init(void)
75 {
76 	reset_dev.of_node = of_find_compatible_node(NULL, NULL,
77 						"ralink,rt2880-reset");
78 	if (!reset_dev.of_node)
79 		pr_err("Failed to find reset controller node");
80 	else
81 		reset_controller_register(&reset_dev);
82 }
83 
84 static void ralink_restart(char *command)
85 {
86 	local_irq_disable();
87 	rt_sysc_w32(RSTCTL_RESET_SYSTEM, SYSC_REG_RESET_CTRL);
88 	unreachable();
89 }
90 
91 static void ralink_halt(void)
92 {
93 	local_irq_disable();
94 	unreachable();
95 }
96 
97 static int __init mips_reboot_setup(void)
98 {
99 	_machine_restart = ralink_restart;
100 	_machine_halt = ralink_halt;
101 	pm_power_off = ralink_halt;
102 
103 	return 0;
104 }
105 
106 arch_initcall(mips_reboot_setup);
107