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
|
/*
* Watchdog driver for Conexant Digicolor
*
* Copyright (C) 2015 Paradox Innovation Ltd.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/types.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/watchdog.h>
#include <linux/reboot.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#define TIMER_A_CONTROL 0
#define TIMER_A_COUNT 4
#define TIMER_A_ENABLE_COUNT BIT(0)
#define TIMER_A_ENABLE_WATCHDOG BIT(1)
struct dc_wdt {
void __iomem *base;
struct clk *clk;
struct notifier_block restart_handler;
spinlock_t lock;
};
static unsigned timeout;
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
static void dc_wdt_set(struct dc_wdt *wdt, u32 ticks)
{
unsigned long flags;
spin_lock_irqsave(&wdt->lock, flags);
writel_relaxed(0, wdt->base + TIMER_A_CONTROL);
writel_relaxed(ticks, wdt->base + TIMER_A_COUNT);
writel_relaxed(TIMER_A_ENABLE_COUNT | TIMER_A_ENABLE_WATCHDOG,
wdt->base + TIMER_A_CONTROL);
spin_unlock_irqrestore(&wdt->lock, flags);
}
static int dc_restart_handler(struct notifier_block *this, unsigned long mode,
void *cmd)
{
struct dc_wdt *wdt = container_of(this, struct dc_wdt, restart_handler);
dc_wdt_set(wdt, 1);
/* wait for reset to assert... */
mdelay(500);
return NOTIFY_DONE;
}
static int dc_wdt_start(struct watchdog_device *wdog)
{
struct dc_wdt *wdt = watchdog_get_drvdata(wdog);
dc_wdt_set(wdt, wdog->timeout * clk_get_rate(wdt->clk));
return 0;
}
static int dc_wdt_stop(struct watchdog_device *wdog)
{
struct dc_wdt *wdt = watchdog_get_drvdata(wdog);
writel_relaxed(0, wdt->base + TIMER_A_CONTROL);
return 0;
}
static int dc_wdt_set_timeout(struct watchdog_device *wdog, unsigned int t)
{
struct dc_wdt *wdt = watchdog_get_drvdata(wdog);
dc_wdt_set(wdt, t * clk_get_rate(wdt->clk));
wdog->timeout = t;
return 0;
}
static unsigned int dc_wdt_get_timeleft(struct watchdog_device *wdog)
{
struct dc_wdt *wdt = watchdog_get_drvdata(wdog);
uint32_t count = readl_relaxed(wdt->base + TIMER_A_COUNT);
return count / clk_get_rate(wdt->clk);
}
static struct watchdog_ops dc_wdt_ops = {
.owner = THIS_MODULE,
.start = dc_wdt_start,
.stop = dc_wdt_stop,
.set_timeout = dc_wdt_set_timeout,
.get_timeleft = dc_wdt_get_timeleft,
};
static struct watchdog_info dc_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE
| WDIOF_KEEPALIVEPING,
.identity = "Conexant Digicolor Watchdog",
};
static struct watchdog_device dc_wdt_wdd = {
.info = &dc_wdt_info,
.ops = &dc_wdt_ops,
.min_timeout = 1,
};
static int dc_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct dc_wdt *wdt;
int ret;
wdt = devm_kzalloc(dev, sizeof(struct dc_wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
platform_set_drvdata(pdev, wdt);
wdt->base = of_iomap(np, 0);
if (!wdt->base) {
dev_err(dev, "Failed to remap watchdog regs");
return -ENODEV;
}
wdt->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(wdt->clk)) {
ret = PTR_ERR(wdt->clk);
goto err_iounmap;
}
dc_wdt_wdd.max_timeout = U32_MAX / clk_get_rate(wdt->clk);
dc_wdt_wdd.timeout = dc_wdt_wdd.max_timeout;
dc_wdt_wdd.parent = &pdev->dev;
spin_lock_init(&wdt->lock);
watchdog_set_drvdata(&dc_wdt_wdd, wdt);
watchdog_init_timeout(&dc_wdt_wdd, timeout, dev);
ret = watchdog_register_device(&dc_wdt_wdd);
if (ret) {
dev_err(dev, "Failed to register watchdog device");
goto err_iounmap;
}
wdt->restart_handler.notifier_call = dc_restart_handler;
wdt->restart_handler.priority = 128;
ret = register_restart_handler(&wdt->restart_handler);
if (ret)
dev_warn(&pdev->dev, "cannot register restart handler\n");
return 0;
err_iounmap:
iounmap(wdt->base);
return ret;
}
static int dc_wdt_remove(struct platform_device *pdev)
{
struct dc_wdt *wdt = platform_get_drvdata(pdev);
unregister_restart_handler(&wdt->restart_handler);
watchdog_unregister_device(&dc_wdt_wdd);
iounmap(wdt->base);
return 0;
}
static void dc_wdt_shutdown(struct platform_device *pdev)
{
dc_wdt_stop(&dc_wdt_wdd);
}
static const struct of_device_id dc_wdt_of_match[] = {
{ .compatible = "cnxt,cx92755-wdt", },
{},
};
MODULE_DEVICE_TABLE(of, dc_wdt_of_match);
static struct platform_driver dc_wdt_driver = {
.probe = dc_wdt_probe,
.remove = dc_wdt_remove,
.shutdown = dc_wdt_shutdown,
.driver = {
.name = "digicolor-wdt",
.of_match_table = dc_wdt_of_match,
},
};
module_platform_driver(dc_wdt_driver);
MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
MODULE_DESCRIPTION("Driver for Conexant Digicolor watchdog timer");
MODULE_LICENSE("GPL");
|
