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
259
260
261
262
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* virtio_rtc RTC class driver
*
* Copyright (C) 2023 OpenSynergy GmbH
* Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
*/
#include <linux/math64.h>
#include <linux/overflow.h>
#include <linux/rtc.h>
#include <linux/time64.h>
#include <uapi/linux/virtio_rtc.h>
#include "virtio_rtc_internal.h"
/**
* struct viortc_class - RTC class wrapper
* @viortc: virtio_rtc device data
* @rtc: RTC device
* @vio_clk_id: virtio_rtc clock id
* @stopped: Whether RTC ops are disallowed. Access protected by rtc_lock().
*/
struct viortc_class {
struct viortc_dev *viortc;
struct rtc_device *rtc;
u16 vio_clk_id;
bool stopped;
};
/**
* viortc_class_get_locked() - get RTC class wrapper, if ops allowed
* @dev: virtio device
*
* Gets the RTC class wrapper from the virtio device, if it is available and
* ops are allowed.
*
* Context: Caller must hold rtc_lock().
* Return: RTC class wrapper if available and ops allowed, ERR_PTR otherwise.
*/
static struct viortc_class *viortc_class_get_locked(struct device *dev)
{
struct viortc_class *viortc_class;
viortc_class = viortc_class_from_dev(dev);
if (IS_ERR(viortc_class))
return viortc_class;
if (viortc_class->stopped)
return ERR_PTR(-EBUSY);
return viortc_class;
}
/**
* viortc_class_read_time() - RTC class op read_time
* @dev: virtio device
* @tm: read time
*
* Context: Process context.
* Return: Zero on success, negative error code otherwise.
*/
static int viortc_class_read_time(struct device *dev, struct rtc_time *tm)
{
struct viortc_class *viortc_class;
time64_t sec;
int ret;
u64 ns;
viortc_class = viortc_class_get_locked(dev);
if (IS_ERR(viortc_class))
return PTR_ERR(viortc_class);
ret = viortc_read(viortc_class->viortc, viortc_class->vio_clk_id, &ns);
if (ret)
return ret;
sec = div_u64(ns, NSEC_PER_SEC);
rtc_time64_to_tm(sec, tm);
return 0;
}
/**
* viortc_class_read_alarm() - RTC class op read_alarm
* @dev: virtio device
* @alrm: alarm read out
*
* Context: Process context.
* Return: Zero on success, negative error code otherwise.
*/
static int viortc_class_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct viortc_class *viortc_class;
time64_t alarm_time_sec;
u64 alarm_time_ns;
bool enabled;
int ret;
viortc_class = viortc_class_get_locked(dev);
if (IS_ERR(viortc_class))
return PTR_ERR(viortc_class);
ret = viortc_read_alarm(viortc_class->viortc, viortc_class->vio_clk_id,
&alarm_time_ns, &enabled);
if (ret)
return ret;
alarm_time_sec = div_u64(alarm_time_ns, NSEC_PER_SEC);
rtc_time64_to_tm(alarm_time_sec, &alrm->time);
alrm->enabled = enabled;
return 0;
}
/**
* viortc_class_set_alarm() - RTC class op set_alarm
* @dev: virtio device
* @alrm: alarm to set
*
* Context: Process context.
* Return: Zero on success, negative error code otherwise.
*/
static int viortc_class_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct viortc_class *viortc_class;
time64_t alarm_time_sec;
u64 alarm_time_ns;
viortc_class = viortc_class_get_locked(dev);
if (IS_ERR(viortc_class))
return PTR_ERR(viortc_class);
alarm_time_sec = rtc_tm_to_time64(&alrm->time);
if (alarm_time_sec < 0)
return -EINVAL;
if (check_mul_overflow((u64)alarm_time_sec, (u64)NSEC_PER_SEC,
&alarm_time_ns))
return -EINVAL;
return viortc_set_alarm(viortc_class->viortc, viortc_class->vio_clk_id,
alarm_time_ns, alrm->enabled);
}
/**
* viortc_class_alarm_irq_enable() - RTC class op alarm_irq_enable
* @dev: virtio device
* @enabled: enable or disable alarm IRQ
*
* Context: Process context.
* Return: Zero on success, negative error code otherwise.
*/
static int viortc_class_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct viortc_class *viortc_class;
viortc_class = viortc_class_get_locked(dev);
if (IS_ERR(viortc_class))
return PTR_ERR(viortc_class);
return viortc_set_alarm_enabled(viortc_class->viortc,
viortc_class->vio_clk_id, enabled);
}
static const struct rtc_class_ops viortc_class_ops = {
.read_time = viortc_class_read_time,
.read_alarm = viortc_class_read_alarm,
.set_alarm = viortc_class_set_alarm,
.alarm_irq_enable = viortc_class_alarm_irq_enable,
};
/**
* viortc_class_alarm() - propagate alarm notification as alarm interrupt
* @viortc_class: RTC class wrapper
* @vio_clk_id: virtio_rtc clock id
*
* Context: Any context.
*/
void viortc_class_alarm(struct viortc_class *viortc_class, u16 vio_clk_id)
{
if (vio_clk_id != viortc_class->vio_clk_id) {
dev_warn_ratelimited(&viortc_class->rtc->dev,
"ignoring alarm for clock id %d, expected id %d\n",
vio_clk_id, viortc_class->vio_clk_id);
return;
}
rtc_update_irq(viortc_class->rtc, 1, RTC_AF | RTC_IRQF);
}
/**
* viortc_class_stop() - disallow RTC class ops
* @viortc_class: RTC class wrapper
*
* Context: Process context. Caller must NOT hold rtc_lock().
*/
void viortc_class_stop(struct viortc_class *viortc_class)
{
rtc_lock(viortc_class->rtc);
viortc_class->stopped = true;
rtc_unlock(viortc_class->rtc);
}
/**
* viortc_class_register() - register RTC class device
* @viortc_class: RTC class wrapper
*
* Context: Process context.
* Return: Zero on success, negative error code otherwise.
*/
int viortc_class_register(struct viortc_class *viortc_class)
{
return devm_rtc_register_device(viortc_class->rtc);
}
/**
* viortc_class_init() - init RTC class wrapper and device
* @viortc: device data
* @vio_clk_id: virtio_rtc clock id
* @have_alarm: have alarm feature
* @parent_dev: virtio device
*
* Context: Process context.
* Return: RTC class wrapper on success, ERR_PTR otherwise.
*/
struct viortc_class *viortc_class_init(struct viortc_dev *viortc,
u16 vio_clk_id, bool have_alarm,
struct device *parent_dev)
{
struct viortc_class *viortc_class;
struct rtc_device *rtc;
viortc_class =
devm_kzalloc(parent_dev, sizeof(*viortc_class), GFP_KERNEL);
if (!viortc_class)
return ERR_PTR(-ENOMEM);
rtc = devm_rtc_allocate_device(parent_dev);
if (IS_ERR(rtc))
return ERR_CAST(rtc);
viortc_class->viortc = viortc;
viortc_class->rtc = rtc;
viortc_class->vio_clk_id = vio_clk_id;
if (!have_alarm)
clear_bit(RTC_FEATURE_ALARM, rtc->features);
clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
rtc->ops = &viortc_class_ops;
rtc->range_max = div_u64(U64_MAX, NSEC_PER_SEC);
return viortc_class;
}
|
