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
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
|
/*
* Ralink RT288x/RT3xxx/MT76xx built-in hardware watchdog timer
*
* Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
* Copyright (C) 2013 John Crispin <john@phrozen.org>
*
* This driver was based on: drivers/watchdog/softdog.c
*
* 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/clk.h>
#include <linux/reset.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/watchdog.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <asm/mach-ralink/ralink_regs.h>
#define SYSC_RSTSTAT 0x38
#define WDT_RST_CAUSE BIT(1)
#define RALINK_WDT_TIMEOUT 30
#define RALINK_WDT_PRESCALE 65536
#define TIMER_REG_TMR1LOAD 0x00
#define TIMER_REG_TMR1CTL 0x08
#define TMRSTAT_TMR1RST BIT(5)
#define TMR1CTL_ENABLE BIT(7)
#define TMR1CTL_MODE_SHIFT 4
#define TMR1CTL_MODE_MASK 0x3
#define TMR1CTL_MODE_FREE_RUNNING 0x0
#define TMR1CTL_MODE_PERIODIC 0x1
#define TMR1CTL_MODE_TIMEOUT 0x2
#define TMR1CTL_MODE_WDT 0x3
#define TMR1CTL_PRESCALE_MASK 0xf
#define TMR1CTL_PRESCALE_65536 0xf
static struct clk *rt288x_wdt_clk;
static unsigned long rt288x_wdt_freq;
static void __iomem *rt288x_wdt_base;
static struct reset_control *rt288x_wdt_reset;
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static inline void rt_wdt_w32(unsigned reg, u32 val)
{
iowrite32(val, rt288x_wdt_base + reg);
}
static inline u32 rt_wdt_r32(unsigned reg)
{
return ioread32(rt288x_wdt_base + reg);
}
static int rt288x_wdt_ping(struct watchdog_device *w)
{
rt_wdt_w32(TIMER_REG_TMR1LOAD, w->timeout * rt288x_wdt_freq);
return 0;
}
static int rt288x_wdt_start(struct watchdog_device *w)
{
u32 t;
t = rt_wdt_r32(TIMER_REG_TMR1CTL);
t &= ~(TMR1CTL_MODE_MASK << TMR1CTL_MODE_SHIFT |
TMR1CTL_PRESCALE_MASK);
t |= (TMR1CTL_MODE_WDT << TMR1CTL_MODE_SHIFT |
TMR1CTL_PRESCALE_65536);
rt_wdt_w32(TIMER_REG_TMR1CTL, t);
rt288x_wdt_ping(w);
t = rt_wdt_r32(TIMER_REG_TMR1CTL);
t |= TMR1CTL_ENABLE;
rt_wdt_w32(TIMER_REG_TMR1CTL, t);
return 0;
}
static int rt288x_wdt_stop(struct watchdog_device *w)
{
u32 t;
rt288x_wdt_ping(w);
t = rt_wdt_r32(TIMER_REG_TMR1CTL);
t &= ~TMR1CTL_ENABLE;
rt_wdt_w32(TIMER_REG_TMR1CTL, t);
return 0;
}
static int rt288x_wdt_set_timeout(struct watchdog_device *w, unsigned int t)
{
w->timeout = t;
rt288x_wdt_ping(w);
return 0;
}
static int rt288x_wdt_bootcause(void)
{
if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE)
return WDIOF_CARDRESET;
return 0;
}
static struct watchdog_info rt288x_wdt_info = {
.identity = "Ralink Watchdog",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
};
static const struct watchdog_ops rt288x_wdt_ops = {
.owner = THIS_MODULE,
.start = rt288x_wdt_start,
.stop = rt288x_wdt_stop,
.ping = rt288x_wdt_ping,
.set_timeout = rt288x_wdt_set_timeout,
};
static struct watchdog_device rt288x_wdt_dev = {
.info = &rt288x_wdt_info,
.ops = &rt288x_wdt_ops,
.min_timeout = 1,
};
static int rt288x_wdt_probe(struct platform_device *pdev)
{
struct resource *res;
int ret;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
rt288x_wdt_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(rt288x_wdt_base))
return PTR_ERR(rt288x_wdt_base);
rt288x_wdt_clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(rt288x_wdt_clk))
return PTR_ERR(rt288x_wdt_clk);
rt288x_wdt_reset = devm_reset_control_get(&pdev->dev, NULL);
if (!IS_ERR(rt288x_wdt_reset))
reset_control_deassert(rt288x_wdt_reset);
rt288x_wdt_freq = clk_get_rate(rt288x_wdt_clk) / RALINK_WDT_PRESCALE;
rt288x_wdt_dev.bootstatus = rt288x_wdt_bootcause();
rt288x_wdt_dev.max_timeout = (0xfffful / rt288x_wdt_freq);
rt288x_wdt_dev.parent = &pdev->dev;
watchdog_init_timeout(&rt288x_wdt_dev, rt288x_wdt_dev.max_timeout,
&pdev->dev);
watchdog_set_nowayout(&rt288x_wdt_dev, nowayout);
ret = watchdog_register_device(&rt288x_wdt_dev);
if (!ret)
dev_info(&pdev->dev, "Initialized\n");
return 0;
}
static int rt288x_wdt_remove(struct platform_device *pdev)
{
watchdog_unregister_device(&rt288x_wdt_dev);
return 0;
}
static void rt288x_wdt_shutdown(struct platform_device *pdev)
{
rt288x_wdt_stop(&rt288x_wdt_dev);
}
static const struct of_device_id rt288x_wdt_match[] = {
{ .compatible = "ralink,rt2880-wdt" },
{},
};
MODULE_DEVICE_TABLE(of, rt288x_wdt_match);
static struct platform_driver rt288x_wdt_driver = {
.probe = rt288x_wdt_probe,
.remove = rt288x_wdt_remove,
.shutdown = rt288x_wdt_shutdown,
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = rt288x_wdt_match,
},
};
module_platform_driver(rt288x_wdt_driver);
MODULE_DESCRIPTION("MediaTek/Ralink RT288x/RT3xxx hardware watchdog driver");
MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org");
MODULE_LICENSE("GPL v2");
|
