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
use crate::pac::{RCC, RTC};
use crate::backup_domain::BackupDomain;
use crate::time::Hertz;
use core::convert::Infallible;
const LSE_HERTZ: u32 = 32_768;
pub struct Rtc {
regs: RTC,
}
impl Rtc {
pub fn rtc(regs: RTC, bkp: &mut BackupDomain) -> Self {
let mut result = Rtc { regs };
Rtc::enable_rtc(bkp);
let prl = LSE_HERTZ - 1;
assert!(prl < 1 << 20);
result.perform_write(|s| {
s.regs.prlh.write(|w| unsafe { w.bits(prl >> 16) });
s.regs.prll.write(|w| unsafe { w.bits(prl as u16 as u32) });
});
result
}
fn enable_rtc(_bkp: &mut BackupDomain) {
let rcc = unsafe { &*RCC::ptr() };
rcc.bdcr.modify(|_, w| {
w
.lseon()
.set_bit()
.rtcen()
.set_bit()
.rtcsel()
.lse()
})
}
pub fn select_frequency(&mut self, timeout: impl Into<Hertz>) {
let frequency = timeout.into().0;
assert!(frequency <= LSE_HERTZ / 2);
let prescaler = LSE_HERTZ / frequency - 1;
self.perform_write(|s| {
s.regs.prlh.write(|w| unsafe { w.bits(prescaler >> 16) });
s.regs
.prll
.write(|w| unsafe { w.bits(prescaler as u16 as u32) });
});
}
pub fn set_time(&mut self, counter_value: u32) {
self.perform_write(|s| {
s.regs
.cnth
.write(|w| unsafe { w.bits(counter_value >> 16) });
s.regs
.cntl
.write(|w| unsafe { w.bits(counter_value as u16 as u32) });
});
}
pub fn set_alarm(&mut self, counter_value: u32) {
let alarm_value = counter_value - 1;
#[allow(unused_unsafe)]
self.perform_write(|s| {
s.regs
.alrh
.write(|w| unsafe { w.alrh().bits((alarm_value >> 16) as u16) });
s.regs
.alrl
.write(|w| unsafe { w.alrl().bits(alarm_value as u16) });
});
self.clear_alarm_flag();
}
pub fn listen_alarm(&mut self) {
self.perform_write(|s| {
s.regs.crh.modify(|_, w| w.alrie().set_bit());
})
}
pub fn unlisten_alarm(&mut self) {
self.perform_write(|s| {
s.regs.crh.modify(|_, w| w.alrie().clear_bit());
})
}
pub fn current_time(&self) -> u32 {
while !self.regs.crl.read().rsf().bit() {}
self.regs.cnth.read().bits() << 16 | self.regs.cntl.read().bits()
}
pub fn listen_seconds(&mut self) {
self.perform_write(|s| s.regs.crh.modify(|_, w| w.secie().set_bit()))
}
pub fn unlisten_seconds(&mut self) {
self.perform_write(|s| s.regs.crh.modify(|_, w| w.secie().clear_bit()))
}
pub fn clear_second_flag(&mut self) {
self.perform_write(|s| s.regs.crl.modify(|_, w| w.secf().clear_bit()))
}
pub fn clear_alarm_flag(&mut self) {
self.perform_write(|s| s.regs.crl.modify(|_, w| w.alrf().clear_bit()))
}
pub fn wait_alarm(&mut self) -> nb::Result<(), Infallible> {
if self.regs.crl.read().alrf().bit() {
self.regs.crl.modify(|_, w| w.alrf().clear_bit());
Ok(())
} else {
Err(nb::Error::WouldBlock)
}
}
fn perform_write(&mut self, func: impl Fn(&mut Self)) {
while !self.regs.crl.read().rtoff().bit() {}
self.regs.crl.modify(|_, w| w.cnf().set_bit());
func(self);
self.regs.crl.modify(|_, w| w.cnf().clear_bit());
while !self.regs.crl.read().rtoff().bit() {}
}
}