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
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
/*
* drivers/watchdog/orion_wdt.c
*
* Watchdog driver for Orion/Kirkwood processors
*
* Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/of.h>
#include <mach/bridge-regs.h>
/*
* Watchdog timer block registers.
*/
#define TIMER_CTRL 0x0000
#define WDT_EN 0x0010
#define WDT_VAL 0x0024
#define WDT_MAX_CYCLE_COUNT 0xffffffff
#define WDT_IN_USE 0
#define WDT_OK_TO_CLOSE 1
static bool nowayout = WATCHDOG_NOWAYOUT;
static int heartbeat = -1; /* module parameter (seconds) */
static unsigned int wdt_max_duration; /* (seconds) */
static struct clk *clk;
static unsigned int wdt_tclk;
static void __iomem *wdt_reg;
static DEFINE_SPINLOCK(wdt_lock);
static int orion_wdt_ping(struct watchdog_device *wdt_dev)
{
spin_lock(&wdt_lock);
/* Reload watchdog duration */
writel(wdt_tclk * wdt_dev->timeout, wdt_reg + WDT_VAL);
spin_unlock(&wdt_lock);
return 0;
}
static int orion_wdt_start(struct watchdog_device *wdt_dev)
{
u32 reg;
spin_lock(&wdt_lock);
/* Set watchdog duration */
writel(wdt_tclk * wdt_dev->timeout, wdt_reg + WDT_VAL);
/* Clear watchdog timer interrupt */
reg = readl(BRIDGE_CAUSE);
reg &= ~WDT_INT_REQ;
writel(reg, BRIDGE_CAUSE);
/* Enable watchdog timer */
reg = readl(wdt_reg + TIMER_CTRL);
reg |= WDT_EN;
writel(reg, wdt_reg + TIMER_CTRL);
/* Enable reset on watchdog */
reg = readl(RSTOUTn_MASK);
reg |= WDT_RESET_OUT_EN;
writel(reg, RSTOUTn_MASK);
spin_unlock(&wdt_lock);
return 0;
}
static int orion_wdt_stop(struct watchdog_device *wdt_dev)
{
u32 reg;
spin_lock(&wdt_lock);
/* Disable reset on watchdog */
reg = readl(RSTOUTn_MASK);
reg &= ~WDT_RESET_OUT_EN;
writel(reg, RSTOUTn_MASK);
/* Disable watchdog timer */
reg = readl(wdt_reg + TIMER_CTRL);
reg &= ~WDT_EN;
writel(reg, wdt_reg + TIMER_CTRL);
spin_unlock(&wdt_lock);
return 0;
}
static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
{
unsigned int time_left;
spin_lock(&wdt_lock);
time_left = readl(wdt_reg + WDT_VAL) / wdt_tclk;
spin_unlock(&wdt_lock);
return time_left;
}
static int orion_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
wdt_dev->timeout = timeout;
return 0;
}
static const struct watchdog_info orion_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "Orion Watchdog",
};
static const struct watchdog_ops orion_wdt_ops = {
.owner = THIS_MODULE,
.start = orion_wdt_start,
.stop = orion_wdt_stop,
.ping = orion_wdt_ping,
.set_timeout = orion_wdt_set_timeout,
.get_timeleft = orion_wdt_get_timeleft,
};
static struct watchdog_device orion_wdt = {
.info = &orion_wdt_info,
.ops = &orion_wdt_ops,
};
static int orion_wdt_probe(struct platform_device *pdev)
{
struct resource *res;
int ret;
clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(clk)) {
dev_err(&pdev->dev, "Orion Watchdog missing clock\n");
return -ENODEV;
}
clk_prepare_enable(clk);
wdt_tclk = clk_get_rate(clk);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
wdt_reg = devm_ioremap(&pdev->dev, res->start, resource_size(res));
if (!wdt_reg)
return -ENOMEM;
wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk;
if ((heartbeat < 1) || (heartbeat > wdt_max_duration))
heartbeat = wdt_max_duration;
orion_wdt.timeout = heartbeat;
orion_wdt.min_timeout = 1;
orion_wdt.max_timeout = wdt_max_duration;
watchdog_set_nowayout(&orion_wdt, nowayout);
ret = watchdog_register_device(&orion_wdt);
if (ret) {
clk_disable_unprepare(clk);
return ret;
}
pr_info("Initial timeout %d sec%s\n",
heartbeat, nowayout ? ", nowayout" : "");
return 0;
}
static int orion_wdt_remove(struct platform_device *pdev)
{
watchdog_unregister_device(&orion_wdt);
clk_disable_unprepare(clk);
return 0;
}
static void orion_wdt_shutdown(struct platform_device *pdev)
{
orion_wdt_stop(&orion_wdt);
}
static const struct of_device_id orion_wdt_of_match_table[] = {
{ .compatible = "marvell,orion-wdt", },
{},
};
MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
static struct platform_driver orion_wdt_driver = {
.probe = orion_wdt_probe,
.remove = orion_wdt_remove,
.shutdown = orion_wdt_shutdown,
.driver = {
.owner = THIS_MODULE,
.name = "orion_wdt",
.of_match_table = of_match_ptr(orion_wdt_of_match_table),
},
};
module_platform_driver(orion_wdt_driver);
MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
MODULE_DESCRIPTION("Orion Processor Watchdog");
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
