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
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2018-2019 NXP.
*/
#include <linux/arm-smccc.h>
#include <linux/firmware/imx/sci.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#define DEFAULT_TIMEOUT 60
/*
* Software timer tick implemented in scfw side, support 10ms to 0xffffffff ms
* in theory, but for normal case, 1s~128s is enough, you can change this max
* value in case it's not enough.
*/
#define MAX_TIMEOUT 128
#define IMX_SIP_TIMER 0xC2000002
#define IMX_SIP_TIMER_START_WDOG 0x01
#define IMX_SIP_TIMER_STOP_WDOG 0x02
#define IMX_SIP_TIMER_SET_WDOG_ACT 0x03
#define IMX_SIP_TIMER_PING_WDOG 0x04
#define IMX_SIP_TIMER_SET_TIMEOUT_WDOG 0x05
#define IMX_SIP_TIMER_GET_WDOG_STAT 0x06
#define IMX_SIP_TIMER_SET_PRETIME_WDOG 0x07
#define SC_TIMER_WDOG_ACTION_PARTITION 0
#define SC_IRQ_WDOG 1
#define SC_IRQ_GROUP_WDOG 1
#define SC_TIMER_ERR_BUSY 10
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0000);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
struct imx_sc_wdt_device {
struct watchdog_device wdd;
struct notifier_block wdt_notifier;
};
static int imx_sc_wdt_ping(struct watchdog_device *wdog)
{
struct arm_smccc_res res;
arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_PING_WDOG,
0, 0, 0, 0, 0, 0, &res);
return 0;
}
static bool imx_sc_wdt_is_running(void)
{
struct arm_smccc_res res;
arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_START_WDOG,
0, 0, 0, 0, 0, 0, &res);
/* Already enabled (SC_TIMER_ERR_BUSY)? */
if (res.a0 == SC_TIMER_ERR_BUSY)
return true;
/* Undo only if that was us who has (successfully) enabled the WDT */
if (!res.a0)
arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_STOP_WDOG,
0, 0, 0, 0, 0, 0, &res);
return false;
}
static int imx_sc_wdt_start(struct watchdog_device *wdog)
{
struct arm_smccc_res res;
arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_START_WDOG,
0, 0, 0, 0, 0, 0, &res);
/* Ignore if already enabled(SC_TIMER_ERR_BUSY) */
if (res.a0 && res.a0 != SC_TIMER_ERR_BUSY)
return -EACCES;
arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_WDOG_ACT,
SC_TIMER_WDOG_ACTION_PARTITION,
0, 0, 0, 0, 0, &res);
return res.a0 ? -EACCES : 0;
}
static int imx_sc_wdt_stop(struct watchdog_device *wdog)
{
struct arm_smccc_res res;
arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_STOP_WDOG,
0, 0, 0, 0, 0, 0, &res);
return res.a0 ? -EACCES : 0;
}
static int imx_sc_wdt_set_timeout(struct watchdog_device *wdog,
unsigned int timeout)
{
struct arm_smccc_res res;
wdog->timeout = timeout;
arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_TIMEOUT_WDOG,
timeout * 1000, 0, 0, 0, 0, 0, &res);
return res.a0 ? -EACCES : 0;
}
static int imx_sc_wdt_set_pretimeout(struct watchdog_device *wdog,
unsigned int pretimeout)
{
struct arm_smccc_res res;
/*
* SCU firmware calculates pretimeout based on current time
* stamp instead of watchdog timeout stamp, need to convert
* the pretimeout to SCU firmware's timeout value.
*/
arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_PRETIME_WDOG,
(wdog->timeout - pretimeout) * 1000, 0, 0, 0,
0, 0, &res);
if (res.a0)
return -EACCES;
wdog->pretimeout = pretimeout;
return 0;
}
static int imx_sc_wdt_notify(struct notifier_block *nb,
unsigned long event, void *group)
{
struct imx_sc_wdt_device *imx_sc_wdd =
container_of(nb,
struct imx_sc_wdt_device,
wdt_notifier);
if (event & SC_IRQ_WDOG &&
*(u8 *)group == SC_IRQ_GROUP_WDOG)
watchdog_notify_pretimeout(&imx_sc_wdd->wdd);
return 0;
}
static void imx_sc_wdt_action(void *data)
{
struct notifier_block *wdt_notifier = data;
imx_scu_irq_unregister_notifier(wdt_notifier);
imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
SC_IRQ_WDOG,
false);
}
static const struct watchdog_ops imx_sc_wdt_ops = {
.owner = THIS_MODULE,
.start = imx_sc_wdt_start,
.stop = imx_sc_wdt_stop,
.ping = imx_sc_wdt_ping,
.set_timeout = imx_sc_wdt_set_timeout,
.set_pretimeout = imx_sc_wdt_set_pretimeout,
};
static struct watchdog_info imx_sc_wdt_info = {
.identity = "i.MX SC watchdog timer",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
};
static int imx_sc_wdt_probe(struct platform_device *pdev)
{
struct imx_sc_wdt_device *imx_sc_wdd;
struct watchdog_device *wdog;
struct device *dev = &pdev->dev;
int ret;
imx_sc_wdd = devm_kzalloc(dev, sizeof(*imx_sc_wdd), GFP_KERNEL);
if (!imx_sc_wdd)
return -ENOMEM;
platform_set_drvdata(pdev, imx_sc_wdd);
wdog = &imx_sc_wdd->wdd;
wdog->info = &imx_sc_wdt_info;
wdog->ops = &imx_sc_wdt_ops;
wdog->min_timeout = 1;
wdog->max_timeout = MAX_TIMEOUT;
wdog->parent = dev;
wdog->timeout = DEFAULT_TIMEOUT;
watchdog_init_timeout(wdog, 0, dev);
ret = imx_sc_wdt_set_timeout(wdog, wdog->timeout);
if (ret)
return ret;
if (imx_sc_wdt_is_running())
set_bit(WDOG_HW_RUNNING, &wdog->status);
watchdog_stop_on_reboot(wdog);
watchdog_stop_on_unregister(wdog);
ret = imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
SC_IRQ_WDOG,
true);
if (ret) {
dev_warn(dev, "Enable irq failed, pretimeout NOT supported\n");
goto register_device;
}
imx_sc_wdd->wdt_notifier.notifier_call = imx_sc_wdt_notify;
ret = imx_scu_irq_register_notifier(&imx_sc_wdd->wdt_notifier);
if (ret) {
imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
SC_IRQ_WDOG,
false);
dev_warn(dev,
"Register irq notifier failed, pretimeout NOT supported\n");
goto register_device;
}
ret = devm_add_action_or_reset(dev, imx_sc_wdt_action,
&imx_sc_wdd->wdt_notifier);
if (!ret)
imx_sc_wdt_info.options |= WDIOF_PRETIMEOUT;
else
dev_warn(dev, "Add action failed, pretimeout NOT supported\n");
register_device:
return devm_watchdog_register_device(dev, wdog);
}
static const struct of_device_id imx_sc_wdt_dt_ids[] = {
{ .compatible = "fsl,imx-sc-wdt", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, imx_sc_wdt_dt_ids);
static struct platform_driver imx_sc_wdt_driver = {
.probe = imx_sc_wdt_probe,
.driver = {
.name = "imx-sc-wdt",
.of_match_table = imx_sc_wdt_dt_ids,
},
};
module_platform_driver(imx_sc_wdt_driver);
MODULE_AUTHOR("Robin Gong <yibin.gong@nxp.com>");
MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver");
MODULE_LICENSE("GPL v2");
|
