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
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* ARM Secure Monitor Call watchdog driver
* Copyright (C) 2022, STMicroelectronics - All Rights Reserved
* This file is based on Linux driver drivers/watchdog/arm_smc_wdt.c
*/
#define LOG_CATEGORY UCLASS_WDT
#include <dm.h>
#include <dm/device_compat.h>
#include <linux/arm-smccc.h>
#include <linux/psci.h>
#include <wdt.h>
#define DRV_NAME "arm_smc_wdt"
#define WDT_TIMEOUT_SECS(TIMEOUT) ((TIMEOUT) / 1000)
enum smcwd_call {
SMCWD_INIT = 0,
SMCWD_SET_TIMEOUT = 1,
SMCWD_ENABLE = 2,
SMCWD_PET = 3,
SMCWD_GET_TIMELEFT = 4,
};
struct smcwd_priv_data {
u32 smc_id;
unsigned int min_timeout;
unsigned int max_timeout;
};
static int smcwd_call(struct udevice *dev, enum smcwd_call call,
unsigned long arg, struct arm_smccc_res *res)
{
struct smcwd_priv_data *priv = dev_get_priv(dev);
struct arm_smccc_res local_res;
if (!res)
res = &local_res;
arm_smccc_smc(priv->smc_id, call, arg, 0, 0, 0, 0, 0, res);
if (res->a0 == PSCI_RET_NOT_SUPPORTED)
return -ENODEV;
if (res->a0 == PSCI_RET_INVALID_PARAMS)
return -EINVAL;
if (res->a0 != PSCI_RET_SUCCESS)
return -EIO;
return 0;
}
static int smcwd_reset(struct udevice *dev)
{
return smcwd_call(dev, SMCWD_PET, 0, NULL);
}
static int smcwd_stop(struct udevice *dev)
{
return smcwd_call(dev, SMCWD_ENABLE, 0, NULL);
}
static int smcwd_start(struct udevice *dev, u64 timeout_ms, ulong flags)
{
struct smcwd_priv_data *priv = dev_get_priv(dev);
u64 timeout_sec = WDT_TIMEOUT_SECS(timeout_ms);
int err;
if (timeout_sec < priv->min_timeout || timeout_sec > priv->max_timeout) {
dev_err(dev, "Timeout value not supported\n");
return -EINVAL;
}
err = smcwd_call(dev, SMCWD_SET_TIMEOUT, timeout_sec, NULL);
if (err) {
dev_err(dev, "Timeout out configuration failed\n");
return err;
}
return smcwd_call(dev, SMCWD_ENABLE, 1, NULL);
}
static int smcwd_probe(struct udevice *dev)
{
struct smcwd_priv_data *priv = dev_get_priv(dev);
struct arm_smccc_res res;
int err;
priv->smc_id = dev_read_u32_default(dev, "arm,smc-id", 0x82003D06);
err = smcwd_call(dev, SMCWD_INIT, 0, &res);
if (err < 0) {
dev_err(dev, "Init failed %i\n", err);
return err;
}
priv->min_timeout = res.a1;
priv->max_timeout = res.a2;
return 0;
}
static const struct wdt_ops smcwd_ops = {
.start = smcwd_start,
.stop = smcwd_stop,
.reset = smcwd_reset,
};
static const struct udevice_id smcwd_dt_ids[] = {
{ .compatible = "arm,smc-wdt" },
{}
};
U_BOOT_DRIVER(wdt_sandbox) = {
.name = "smcwd",
.id = UCLASS_WDT,
.of_match = smcwd_dt_ids,
.priv_auto = sizeof(struct smcwd_priv_data),
.probe = smcwd_probe,
.ops = &smcwd_ops,
};
|
