1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
|
/*
* TI keystone reboot driver
*
* Copyright (C) 2014 Texas Instruments Incorporated. http://www.ti.com/
*
* Author: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/io.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <linux/of_platform.h>
#define RSTYPE_RG 0x0
#define RSCTRL_RG 0x4
#define RSCFG_RG 0x8
#define RSISO_RG 0xc
#define RSCTRL_KEY_MASK 0x0000ffff
#define RSCTRL_RESET_MASK BIT(16)
#define RSCTRL_KEY 0x5a69
#define RSMUX_OMODE_MASK 0xe
#define RSMUX_OMODE_RESET_ON 0xa
#define RSMUX_OMODE_RESET_OFF 0x0
#define RSMUX_LOCK_MASK 0x1
#define RSMUX_LOCK_SET 0x1
#define RSCFG_RSTYPE_SOFT 0x300f
#define RSCFG_RSTYPE_HARD 0x0
#define WDT_MUX_NUMBER 0x4
static int rspll_offset;
static struct regmap *pllctrl_regs;
/**
* rsctrl_enable_rspll_write - enable access to RSCTRL, RSCFG
* To be able to access to RSCTRL, RSCFG registers
* we have to write a key before
*/
static inline int rsctrl_enable_rspll_write(void)
{
return regmap_update_bits(pllctrl_regs, rspll_offset + RSCTRL_RG,
RSCTRL_KEY_MASK, RSCTRL_KEY);
}
static int rsctrl_restart_handler(struct notifier_block *this,
unsigned long mode, void *cmd)
{
/* enable write access to RSTCTRL */
rsctrl_enable_rspll_write();
/* reset the SOC */
regmap_update_bits(pllctrl_regs, rspll_offset + RSCTRL_RG,
RSCTRL_RESET_MASK, 0);
return NOTIFY_DONE;
}
static struct notifier_block rsctrl_restart_nb = {
.notifier_call = rsctrl_restart_handler,
.priority = 128,
};
static struct of_device_id rsctrl_of_match[] = {
{.compatible = "ti,keystone-reset", },
{},
};
static int rsctrl_probe(struct platform_device *pdev)
{
int i;
int ret;
u32 val;
unsigned int rg;
u32 rsmux_offset;
struct regmap *devctrl_regs;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
if (!np)
return -ENODEV;
/* get regmaps */
pllctrl_regs = syscon_regmap_lookup_by_phandle(np, "ti,syscon-pll");
if (IS_ERR(pllctrl_regs))
return PTR_ERR(pllctrl_regs);
devctrl_regs = syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
if (IS_ERR(devctrl_regs))
return PTR_ERR(devctrl_regs);
ret = of_property_read_u32_index(np, "ti,syscon-pll", 1, &rspll_offset);
if (ret) {
dev_err(dev, "couldn't read the reset pll offset!\n");
return -EINVAL;
}
ret = of_property_read_u32_index(np, "ti,syscon-dev", 1, &rsmux_offset);
if (ret) {
dev_err(dev, "couldn't read the rsmux offset!\n");
return -EINVAL;
}
/* set soft/hard reset */
val = of_property_read_bool(np, "ti,soft-reset");
val = val ? RSCFG_RSTYPE_SOFT : RSCFG_RSTYPE_HARD;
ret = rsctrl_enable_rspll_write();
if (ret)
return ret;
ret = regmap_write(pllctrl_regs, rspll_offset + RSCFG_RG, val);
if (ret)
return ret;
/* disable a reset isolation for all module clocks */
ret = regmap_write(pllctrl_regs, rspll_offset + RSISO_RG, 0);
if (ret)
return ret;
/* enable a reset for watchdogs from wdt-list */
for (i = 0; i < WDT_MUX_NUMBER; i++) {
ret = of_property_read_u32_index(np, "ti,wdt-list", i, &val);
if (ret == -EOVERFLOW && !i) {
dev_err(dev, "ti,wdt-list property has to contain at"
"least one entry\n");
return -EINVAL;
} else if (ret) {
break;
}
if (val >= WDT_MUX_NUMBER) {
dev_err(dev, "ti,wdt-list property can contain"
"only numbers < 4\n");
return -EINVAL;
}
rg = rsmux_offset + val * 4;
ret = regmap_update_bits(devctrl_regs, rg, RSMUX_OMODE_MASK,
RSMUX_OMODE_RESET_ON |
RSMUX_LOCK_SET);
if (ret)
return ret;
}
ret = register_restart_handler(&rsctrl_restart_nb);
if (ret)
dev_err(dev, "cannot register restart handler (err=%d)\n", ret);
return ret;
}
static struct platform_driver rsctrl_driver = {
.probe = rsctrl_probe,
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = rsctrl_of_match,
},
};
module_platform_driver(rsctrl_driver);
MODULE_AUTHOR("Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>");
MODULE_DESCRIPTION("Texas Instruments keystone reset driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" KBUILD_MODNAME);
|
