/
mod.rs
1224 lines (1090 loc) · 40.2 KB
/
mod.rs
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
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
//! UART driver.
use core::future::poll_fn;
use core::marker::PhantomData;
use core::task::Poll;
use atomic_polyfill::{AtomicU16, Ordering};
use embassy_futures::select::{select, Either};
use embassy_hal_internal::{into_ref, PeripheralRef};
use embassy_sync::waitqueue::AtomicWaker;
use embassy_time::Timer;
use pac::uart::regs::Uartris;
use crate::clocks::clk_peri_freq;
use crate::dma::{AnyChannel, Channel};
use crate::gpio::{AnyPin, SealedPin};
use crate::interrupt::typelevel::{Binding, Interrupt};
use crate::pac::io::vals::{Inover, Outover};
use crate::{interrupt, pac, peripherals, Peripheral, RegExt};
mod buffered;
pub use buffered::{BufferedInterruptHandler, BufferedUart, BufferedUartRx, BufferedUartTx};
/// Word length.
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
pub enum DataBits {
/// 5 bits.
DataBits5,
/// 6 bits.
DataBits6,
/// 7 bits.
DataBits7,
/// 8 bits.
DataBits8,
}
impl DataBits {
fn bits(&self) -> u8 {
match self {
Self::DataBits5 => 0b00,
Self::DataBits6 => 0b01,
Self::DataBits7 => 0b10,
Self::DataBits8 => 0b11,
}
}
}
/// Parity bit.
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
pub enum Parity {
/// No parity.
ParityNone,
/// Even parity.
ParityEven,
/// Odd parity.
ParityOdd,
}
/// Stop bits.
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
pub enum StopBits {
#[doc = "1 stop bit"]
STOP1,
#[doc = "2 stop bits"]
STOP2,
}
/// UART config.
#[non_exhaustive]
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
pub struct Config {
/// Baud rate.
pub baudrate: u32,
/// Word length.
pub data_bits: DataBits,
/// Stop bits.
pub stop_bits: StopBits,
/// Parity bit.
pub parity: Parity,
/// Invert the tx pin output
pub invert_tx: bool,
/// Invert the rx pin input
pub invert_rx: bool,
/// Invert the rts pin
pub invert_rts: bool,
/// Invert the cts pin
pub invert_cts: bool,
}
impl Default for Config {
fn default() -> Self {
Self {
baudrate: 115200,
data_bits: DataBits::DataBits8,
stop_bits: StopBits::STOP1,
parity: Parity::ParityNone,
invert_rx: false,
invert_tx: false,
invert_rts: false,
invert_cts: false,
}
}
}
/// Serial error
#[derive(Debug, Eq, PartialEq, Copy, Clone)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
#[non_exhaustive]
pub enum Error {
/// Triggered when the FIFO (or shift-register) is overflowed.
Overrun,
/// Triggered when a break is received
Break,
/// Triggered when there is a parity mismatch between what's received and
/// our settings.
Parity,
/// Triggered when the received character didn't have a valid stop bit.
Framing,
}
/// Read To Break error
#[derive(Debug, Eq, PartialEq, Copy, Clone)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
#[non_exhaustive]
pub enum ReadToBreakError {
/// Read this many bytes, but never received a line break.
MissingBreak(usize),
/// Other, standard issue with the serial request
Other(Error),
}
/// Internal DMA state of UART RX.
pub struct DmaState {
rx_err_waker: AtomicWaker,
rx_errs: AtomicU16,
}
/// UART driver.
pub struct Uart<'d, T: Instance, M: Mode> {
tx: UartTx<'d, T, M>,
rx: UartRx<'d, T, M>,
}
/// UART TX driver.
pub struct UartTx<'d, T: Instance, M: Mode> {
tx_dma: Option<PeripheralRef<'d, AnyChannel>>,
phantom: PhantomData<(&'d mut T, M)>,
}
/// UART RX driver.
pub struct UartRx<'d, T: Instance, M: Mode> {
rx_dma: Option<PeripheralRef<'d, AnyChannel>>,
phantom: PhantomData<(&'d mut T, M)>,
}
impl<'d, T: Instance, M: Mode> UartTx<'d, T, M> {
/// Create a new DMA-enabled UART which can only send data
pub fn new(
_uart: impl Peripheral<P = T> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
tx_dma: impl Peripheral<P = impl Channel> + 'd,
config: Config,
) -> Self {
into_ref!(tx, tx_dma);
Uart::<T, M>::init(Some(tx.map_into()), None, None, None, config);
Self::new_inner(Some(tx_dma.map_into()))
}
fn new_inner(tx_dma: Option<PeripheralRef<'d, AnyChannel>>) -> Self {
Self {
tx_dma,
phantom: PhantomData,
}
}
/// Transmit the provided buffer blocking execution until done.
pub fn blocking_write(&mut self, buffer: &[u8]) -> Result<(), Error> {
let r = T::regs();
for &b in buffer {
while r.uartfr().read().txff() {}
r.uartdr().write(|w| w.set_data(b));
}
Ok(())
}
/// Flush UART TX blocking execution until done.
pub fn blocking_flush(&mut self) -> Result<(), Error> {
let r = T::regs();
while !r.uartfr().read().txfe() {}
Ok(())
}
/// Check if UART is busy transmitting.
pub fn busy(&self) -> bool {
T::regs().uartfr().read().busy()
}
/// Assert a break condition after waiting for the transmit buffers to empty,
/// for the specified number of bit times. This condition must be asserted
/// for at least two frame times to be effective, `bits` will adjusted
/// according to frame size, parity, and stop bit settings to ensure this.
///
/// This method may block for a long amount of time since it has to wait
/// for the transmit fifo to empty, which may take a while on slow links.
pub async fn send_break(&mut self, bits: u32) {
let regs = T::regs();
let bits = bits.max({
let lcr = regs.uartlcr_h().read();
let width = lcr.wlen() as u32 + 5;
let parity = lcr.pen() as u32;
let stops = 1 + lcr.stp2() as u32;
2 * (1 + width + parity + stops)
});
let divx64 = (((regs.uartibrd().read().baud_divint() as u32) << 6)
+ regs.uartfbrd().read().baud_divfrac() as u32) as u64;
let div_clk = clk_peri_freq() as u64 * 64;
let wait_usecs = (1_000_000 * bits as u64 * divx64 * 16 + div_clk - 1) / div_clk;
self.blocking_flush().unwrap();
while self.busy() {}
regs.uartlcr_h().write_set(|w| w.set_brk(true));
Timer::after_micros(wait_usecs).await;
regs.uartlcr_h().write_clear(|w| w.set_brk(true));
}
}
impl<'d, T: Instance> UartTx<'d, T, Blocking> {
/// Convert this uart TX instance into a buffered uart using the provided
/// irq and transmit buffer.
pub fn into_buffered(
self,
irq: impl Binding<T::Interrupt, BufferedInterruptHandler<T>>,
tx_buffer: &'d mut [u8],
) -> BufferedUartTx<'d, T> {
buffered::init_buffers::<T>(irq, tx_buffer, &mut []);
BufferedUartTx { phantom: PhantomData }
}
}
impl<'d, T: Instance> UartTx<'d, T, Async> {
/// Write to UART TX from the provided buffer using DMA.
pub async fn write(&mut self, buffer: &[u8]) -> Result<(), Error> {
let ch = self.tx_dma.as_mut().unwrap();
let transfer = unsafe {
T::regs().uartdmacr().write_set(|reg| {
reg.set_txdmae(true);
});
// If we don't assign future to a variable, the data register pointer
// is held across an await and makes the future non-Send.
crate::dma::write(ch, buffer, T::regs().uartdr().as_ptr() as *mut _, T::TX_DREQ)
};
transfer.await;
Ok(())
}
}
impl<'d, T: Instance, M: Mode> UartRx<'d, T, M> {
/// Create a new DMA-enabled UART which can only receive data
pub fn new(
_uart: impl Peripheral<P = T> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
_irq: impl Binding<T::Interrupt, InterruptHandler<T>>,
rx_dma: impl Peripheral<P = impl Channel> + 'd,
config: Config,
) -> Self {
into_ref!(rx, rx_dma);
Uart::<T, M>::init(None, Some(rx.map_into()), None, None, config);
Self::new_inner(true, Some(rx_dma.map_into()))
}
fn new_inner(has_irq: bool, rx_dma: Option<PeripheralRef<'d, AnyChannel>>) -> Self {
debug_assert_eq!(has_irq, rx_dma.is_some());
if has_irq {
// disable all error interrupts initially
T::regs().uartimsc().write(|w| w.0 = 0);
T::Interrupt::unpend();
unsafe { T::Interrupt::enable() };
}
Self {
rx_dma,
phantom: PhantomData,
}
}
/// Read from UART RX blocking execution until done.
pub fn blocking_read(&mut self, mut buffer: &mut [u8]) -> Result<(), Error> {
while !buffer.is_empty() {
let received = self.drain_fifo(buffer).map_err(|(_i, e)| e)?;
buffer = &mut buffer[received..];
}
Ok(())
}
/// Returns Ok(len) if no errors occurred. Returns Err((len, err)) if an error was
/// encountered. in both cases, `len` is the number of *good* bytes copied into
/// `buffer`.
fn drain_fifo(&mut self, buffer: &mut [u8]) -> Result<usize, (usize, Error)> {
let r = T::regs();
for (i, b) in buffer.iter_mut().enumerate() {
if r.uartfr().read().rxfe() {
return Ok(i);
}
let dr = r.uartdr().read();
if dr.oe() {
return Err((i, Error::Overrun));
} else if dr.be() {
return Err((i, Error::Break));
} else if dr.pe() {
return Err((i, Error::Parity));
} else if dr.fe() {
return Err((i, Error::Framing));
} else {
*b = dr.data();
}
}
Ok(buffer.len())
}
}
impl<'d, T: Instance, M: Mode> Drop for UartRx<'d, T, M> {
fn drop(&mut self) {
if self.rx_dma.is_some() {
T::Interrupt::disable();
// clear dma flags. irq handlers use these to disambiguate among themselves.
T::regs().uartdmacr().write_clear(|reg| {
reg.set_rxdmae(true);
reg.set_txdmae(true);
reg.set_dmaonerr(true);
});
}
}
}
impl<'d, T: Instance> UartRx<'d, T, Blocking> {
/// Create a new UART RX instance for blocking mode operations.
pub fn new_blocking(
_uart: impl Peripheral<P = T> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
config: Config,
) -> Self {
into_ref!(rx);
Uart::<T, Blocking>::init(None, Some(rx.map_into()), None, None, config);
Self::new_inner(false, None)
}
/// Convert this uart RX instance into a buffered uart using the provided
/// irq and receive buffer.
pub fn into_buffered(
self,
irq: impl Binding<T::Interrupt, BufferedInterruptHandler<T>>,
rx_buffer: &'d mut [u8],
) -> BufferedUartRx<'d, T> {
buffered::init_buffers::<T>(irq, &mut [], rx_buffer);
BufferedUartRx { phantom: PhantomData }
}
}
/// Interrupt handler.
pub struct InterruptHandler<T: Instance> {
_uart: PhantomData<T>,
}
impl<T: Instance> interrupt::typelevel::Handler<T::Interrupt> for InterruptHandler<T> {
unsafe fn on_interrupt() {
let uart = T::regs();
if !uart.uartdmacr().read().rxdmae() {
return;
}
let state = T::dma_state();
let errs = uart.uartris().read();
state.rx_errs.store(errs.0 as u16, Ordering::Relaxed);
state.rx_err_waker.wake();
// disable the error interrupts instead of clearing the flags. clearing the
// flags would allow the dma transfer to continue, potentially signaling
// completion before we can check for errors that happened *during* the transfer.
uart.uartimsc().write_clear(|w| w.0 = errs.0);
}
}
impl<'d, T: Instance> UartRx<'d, T, Async> {
/// Read from UART RX into the provided buffer.
pub async fn read(&mut self, buffer: &mut [u8]) -> Result<(), Error> {
// clear error flags before we drain the fifo. errors that have accumulated
// in the flags will also be present in the fifo.
T::dma_state().rx_errs.store(0, Ordering::Relaxed);
T::regs().uarticr().write(|w| {
w.set_oeic(true);
w.set_beic(true);
w.set_peic(true);
w.set_feic(true);
});
// then drain the fifo. we need to read at most 32 bytes. errors that apply
// to fifo bytes will be reported directly.
let buffer = match {
let limit = buffer.len().min(32);
self.drain_fifo(&mut buffer[0..limit])
} {
Ok(len) if len < buffer.len() => &mut buffer[len..],
Ok(_) => return Ok(()),
Err((_i, e)) => return Err(e),
};
// start a dma transfer. if errors have happened in the interim some error
// interrupt flags will have been raised, and those will be picked up immediately
// by the interrupt handler.
let ch = self.rx_dma.as_mut().unwrap();
T::regs().uartimsc().write_set(|w| {
w.set_oeim(true);
w.set_beim(true);
w.set_peim(true);
w.set_feim(true);
});
T::regs().uartdmacr().write_set(|reg| {
reg.set_rxdmae(true);
reg.set_dmaonerr(true);
});
let transfer = unsafe {
// If we don't assign future to a variable, the data register pointer
// is held across an await and makes the future non-Send.
crate::dma::read(ch, T::regs().uartdr().as_ptr() as *const _, buffer, T::RX_DREQ)
};
// wait for either the transfer to complete or an error to happen.
let transfer_result = select(
transfer,
poll_fn(|cx| {
T::dma_state().rx_err_waker.register(cx.waker());
match T::dma_state().rx_errs.swap(0, Ordering::Relaxed) {
0 => Poll::Pending,
e => Poll::Ready(Uartris(e as u32)),
}
}),
)
.await;
let errors = match transfer_result {
Either::First(()) => {
// We're here because the DMA finished, BUT if an error occurred on the LAST
// byte, then we may still need to grab the error state!
Uartris(T::dma_state().rx_errs.swap(0, Ordering::Relaxed) as u32)
}
Either::Second(e) => {
// We're here because we errored, which means this is the error that
// was problematic.
e
}
};
// If we got no error, just return at this point
if errors.0 == 0 {
return Ok(());
}
// If we DID get an error, we need to figure out which one it was.
if errors.oeris() {
return Err(Error::Overrun);
} else if errors.beris() {
return Err(Error::Break);
} else if errors.peris() {
return Err(Error::Parity);
} else if errors.feris() {
return Err(Error::Framing);
}
unreachable!("unrecognized rx error");
}
/// Read from the UART, waiting for a line break.
///
/// We read until one of the following occurs:
///
/// * We read `buffer.len()` bytes without a line break
/// * returns `Err(ReadToBreakError::MissingBreak(buffer.len()))`
/// * We read `n` bytes then a line break occurs
/// * returns `Ok(n)`
/// * We encounter some error OTHER than a line break
/// * returns `Err(ReadToBreakError::Other(error))`
///
/// **NOTE**: you MUST provide a buffer one byte larger than your largest expected
/// message to reliably detect the framing on one single call to `read_to_break()`.
///
/// * If you expect a message of 20 bytes + line break, and provide a 20-byte buffer:
/// * The first call to `read_to_break()` will return `Err(ReadToBreakError::MissingBreak(20))`
/// * The next call to `read_to_break()` will immediately return `Ok(0)`, from the "stale" line break
/// * If you expect a message of 20 bytes + line break, and provide a 21-byte buffer:
/// * The first call to `read_to_break()` will return `Ok(20)`.
/// * The next call to `read_to_break()` will work as expected
pub async fn read_to_break(&mut self, buffer: &mut [u8]) -> Result<usize, ReadToBreakError> {
// clear error flags before we drain the fifo. errors that have accumulated
// in the flags will also be present in the fifo.
T::dma_state().rx_errs.store(0, Ordering::Relaxed);
T::regs().uarticr().write(|w| {
w.set_oeic(true);
w.set_beic(true);
w.set_peic(true);
w.set_feic(true);
});
// then drain the fifo. we need to read at most 32 bytes. errors that apply
// to fifo bytes will be reported directly.
let sbuffer = match {
let limit = buffer.len().min(32);
self.drain_fifo(&mut buffer[0..limit])
} {
// Drained fifo, still some room left!
Ok(len) if len < buffer.len() => &mut buffer[len..],
// Drained (some/all of the fifo), no room left
Ok(len) => return Err(ReadToBreakError::MissingBreak(len)),
// We got a break WHILE draining the FIFO, return what we did get before the break
Err((i, Error::Break)) => return Ok(i),
// Some other error, just return the error
Err((_i, e)) => return Err(ReadToBreakError::Other(e)),
};
// start a dma transfer. if errors have happened in the interim some error
// interrupt flags will have been raised, and those will be picked up immediately
// by the interrupt handler.
let mut ch = self.rx_dma.as_mut().unwrap();
T::regs().uartimsc().write_set(|w| {
w.set_oeim(true);
w.set_beim(true);
w.set_peim(true);
w.set_feim(true);
});
T::regs().uartdmacr().write_set(|reg| {
reg.set_rxdmae(true);
reg.set_dmaonerr(true);
});
let transfer = unsafe {
// If we don't assign future to a variable, the data register pointer
// is held across an await and makes the future non-Send.
crate::dma::read(&mut ch, T::regs().uartdr().as_ptr() as *const _, sbuffer, T::RX_DREQ)
};
// wait for either the transfer to complete or an error to happen.
let transfer_result = select(
transfer,
poll_fn(|cx| {
T::dma_state().rx_err_waker.register(cx.waker());
match T::dma_state().rx_errs.swap(0, Ordering::Relaxed) {
0 => Poll::Pending,
e => Poll::Ready(Uartris(e as u32)),
}
}),
)
.await;
// Figure out our error state
let errors = match transfer_result {
Either::First(()) => {
// We're here because the DMA finished, BUT if an error occurred on the LAST
// byte, then we may still need to grab the error state!
Uartris(T::dma_state().rx_errs.swap(0, Ordering::Relaxed) as u32)
}
Either::Second(e) => {
// We're here because we errored, which means this is the error that
// was problematic.
e
}
};
if errors.0 == 0 {
// No errors? That means we filled the buffer without a line break.
// For THIS function, that's a problem.
return Err(ReadToBreakError::MissingBreak(buffer.len()));
} else if errors.beris() {
// We got a Line Break! By this point, we've finished/aborted the DMA
// transaction, which means that we need to figure out where it left off
// by looking at the write_addr.
//
// First, we do a sanity check to make sure the write value is within the
// range of DMA we just did.
let sval = buffer.as_ptr() as usize;
let eval = sval + buffer.len();
// This is the address where the DMA would write to next
let next_addr = ch.regs().write_addr().read() as usize;
// If we DON'T end up inside the range, something has gone really wrong.
// Note that it's okay that `eval` is one past the end of the slice, as
// this is where the write pointer will end up at the end of a full
// transfer.
if (next_addr < sval) || (next_addr > eval) {
unreachable!("UART DMA reported invalid `write_addr`");
}
let regs = T::regs();
let all_full = next_addr == eval;
// NOTE: This is off label usage of RSR! See the issue below for
// why I am not checking if there is an "extra" FIFO byte, and why
// I am checking RSR directly (it seems to report the status of the LAST
// POPPED value, rather than the NEXT TO POP value like the datasheet
// suggests!)
//
// issue: https://github.com/raspberrypi/pico-feedback/issues/367
let last_was_break = regs.uartrsr().read().be();
return match (all_full, last_was_break) {
(true, true) | (false, _) => {
// We got less than the full amount + a break, or the full amount
// and the last byte was a break. Subtract the break off by adding one to sval.
Ok(next_addr.saturating_sub(1 + sval))
}
(true, false) => {
// We finished the whole DMA, and the last DMA'd byte was NOT a break
// character. This is an error.
//
// NOTE: we COULD potentially return Ok(buffer.len()) here, since we
// know a line break occured at SOME POINT after the DMA completed.
//
// However, we have no way of knowing if there was extra data BEFORE
// that line break, so instead return an Err to signal to the caller
// that there are "leftovers", and they'll catch the actual line break
// on the next call.
//
// Doing it like this also avoids racyness: now whether you finished
// the full read BEFORE the line break occurred or AFTER the line break
// occurs, you still get `MissingBreak(buffer.len())` instead of sometimes
// getting `Ok(buffer.len())` if you were "late enough" to observe the
// line break.
Err(ReadToBreakError::MissingBreak(buffer.len()))
}
};
} else if errors.oeris() {
return Err(ReadToBreakError::Other(Error::Overrun));
} else if errors.peris() {
return Err(ReadToBreakError::Other(Error::Parity));
} else if errors.feris() {
return Err(ReadToBreakError::Other(Error::Framing));
}
unreachable!("unrecognized rx error");
}
}
impl<'d, T: Instance> Uart<'d, T, Blocking> {
/// Create a new UART without hardware flow control
pub fn new_blocking(
uart: impl Peripheral<P = T> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
config: Config,
) -> Self {
into_ref!(tx, rx);
Self::new_inner(
uart,
tx.map_into(),
rx.map_into(),
None,
None,
false,
None,
None,
config,
)
}
/// Create a new UART with hardware flow control (RTS/CTS)
pub fn new_with_rtscts_blocking(
uart: impl Peripheral<P = T> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
rts: impl Peripheral<P = impl RtsPin<T>> + 'd,
cts: impl Peripheral<P = impl CtsPin<T>> + 'd,
config: Config,
) -> Self {
into_ref!(tx, rx, cts, rts);
Self::new_inner(
uart,
tx.map_into(),
rx.map_into(),
Some(rts.map_into()),
Some(cts.map_into()),
false,
None,
None,
config,
)
}
/// Convert this uart instance into a buffered uart using the provided
/// irq, transmit and receive buffers.
pub fn into_buffered(
self,
irq: impl Binding<T::Interrupt, BufferedInterruptHandler<T>>,
tx_buffer: &'d mut [u8],
rx_buffer: &'d mut [u8],
) -> BufferedUart<'d, T> {
buffered::init_buffers::<T>(irq, tx_buffer, rx_buffer);
BufferedUart {
rx: BufferedUartRx { phantom: PhantomData },
tx: BufferedUartTx { phantom: PhantomData },
}
}
}
impl<'d, T: Instance> Uart<'d, T, Async> {
/// Create a new DMA enabled UART without hardware flow control
pub fn new(
uart: impl Peripheral<P = T> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
_irq: impl Binding<T::Interrupt, InterruptHandler<T>>,
tx_dma: impl Peripheral<P = impl Channel> + 'd,
rx_dma: impl Peripheral<P = impl Channel> + 'd,
config: Config,
) -> Self {
into_ref!(tx, rx, tx_dma, rx_dma);
Self::new_inner(
uart,
tx.map_into(),
rx.map_into(),
None,
None,
true,
Some(tx_dma.map_into()),
Some(rx_dma.map_into()),
config,
)
}
/// Create a new DMA enabled UART with hardware flow control (RTS/CTS)
pub fn new_with_rtscts(
uart: impl Peripheral<P = T> + 'd,
tx: impl Peripheral<P = impl TxPin<T>> + 'd,
rx: impl Peripheral<P = impl RxPin<T>> + 'd,
rts: impl Peripheral<P = impl RtsPin<T>> + 'd,
cts: impl Peripheral<P = impl CtsPin<T>> + 'd,
_irq: impl Binding<T::Interrupt, InterruptHandler<T>>,
tx_dma: impl Peripheral<P = impl Channel> + 'd,
rx_dma: impl Peripheral<P = impl Channel> + 'd,
config: Config,
) -> Self {
into_ref!(tx, rx, cts, rts, tx_dma, rx_dma);
Self::new_inner(
uart,
tx.map_into(),
rx.map_into(),
Some(rts.map_into()),
Some(cts.map_into()),
true,
Some(tx_dma.map_into()),
Some(rx_dma.map_into()),
config,
)
}
}
impl<'d, T: Instance + 'd, M: Mode> Uart<'d, T, M> {
fn new_inner(
_uart: impl Peripheral<P = T> + 'd,
mut tx: PeripheralRef<'d, AnyPin>,
mut rx: PeripheralRef<'d, AnyPin>,
mut rts: Option<PeripheralRef<'d, AnyPin>>,
mut cts: Option<PeripheralRef<'d, AnyPin>>,
has_irq: bool,
tx_dma: Option<PeripheralRef<'d, AnyChannel>>,
rx_dma: Option<PeripheralRef<'d, AnyChannel>>,
config: Config,
) -> Self {
Self::init(
Some(tx.reborrow()),
Some(rx.reborrow()),
rts.as_mut().map(|x| x.reborrow()),
cts.as_mut().map(|x| x.reborrow()),
config,
);
Self {
tx: UartTx::new_inner(tx_dma),
rx: UartRx::new_inner(has_irq, rx_dma),
}
}
fn init(
tx: Option<PeripheralRef<'_, AnyPin>>,
rx: Option<PeripheralRef<'_, AnyPin>>,
rts: Option<PeripheralRef<'_, AnyPin>>,
cts: Option<PeripheralRef<'_, AnyPin>>,
config: Config,
) {
let r = T::regs();
if let Some(pin) = &tx {
pin.gpio().ctrl().write(|w| {
w.set_funcsel(2);
w.set_outover(if config.invert_tx {
Outover::INVERT
} else {
Outover::NORMAL
});
});
pin.pad_ctrl().write(|w| w.set_ie(true));
}
if let Some(pin) = &rx {
pin.gpio().ctrl().write(|w| {
w.set_funcsel(2);
w.set_inover(if config.invert_rx {
Inover::INVERT
} else {
Inover::NORMAL
});
});
pin.pad_ctrl().write(|w| w.set_ie(true));
}
if let Some(pin) = &cts {
pin.gpio().ctrl().write(|w| {
w.set_funcsel(2);
w.set_inover(if config.invert_cts {
Inover::INVERT
} else {
Inover::NORMAL
});
});
pin.pad_ctrl().write(|w| w.set_ie(true));
}
if let Some(pin) = &rts {
pin.gpio().ctrl().write(|w| {
w.set_funcsel(2);
w.set_outover(if config.invert_rts {
Outover::INVERT
} else {
Outover::NORMAL
});
});
pin.pad_ctrl().write(|w| w.set_ie(true));
}
Self::set_baudrate_inner(config.baudrate);
let (pen, eps) = match config.parity {
Parity::ParityNone => (false, false),
Parity::ParityOdd => (true, false),
Parity::ParityEven => (true, true),
};
r.uartlcr_h().write(|w| {
w.set_wlen(config.data_bits.bits());
w.set_stp2(config.stop_bits == StopBits::STOP2);
w.set_pen(pen);
w.set_eps(eps);
w.set_fen(true);
});
r.uartifls().write(|w| {
w.set_rxiflsel(0b000);
w.set_txiflsel(0b000);
});
r.uartcr().write(|w| {
w.set_uarten(true);
w.set_rxe(true);
w.set_txe(true);
w.set_ctsen(cts.is_some());
w.set_rtsen(rts.is_some());
});
}
/// sets baudrate on runtime
pub fn set_baudrate(&mut self, baudrate: u32) {
Self::set_baudrate_inner(baudrate);
}
fn set_baudrate_inner(baudrate: u32) {
let r = T::regs();
let clk_base = crate::clocks::clk_peri_freq();
let baud_rate_div = (8 * clk_base) / baudrate;
let mut baud_ibrd = baud_rate_div >> 7;
let mut baud_fbrd = ((baud_rate_div & 0x7f) + 1) / 2;
if baud_ibrd == 0 {
baud_ibrd = 1;
baud_fbrd = 0;
} else if baud_ibrd >= 65535 {
baud_ibrd = 65535;
baud_fbrd = 0;
}
// Load PL011's baud divisor registers
r.uartibrd().write_value(pac::uart::regs::Uartibrd(baud_ibrd));
r.uartfbrd().write_value(pac::uart::regs::Uartfbrd(baud_fbrd));
// PL011 needs a (dummy) line control register write to latch in the
// divisors. We don't want to actually change LCR contents here.
r.uartlcr_h().modify(|_| {});
}
}
impl<'d, T: Instance, M: Mode> Uart<'d, T, M> {
/// Transmit the provided buffer blocking execution until done.
pub fn blocking_write(&mut self, buffer: &[u8]) -> Result<(), Error> {
self.tx.blocking_write(buffer)
}
/// Flush UART TX blocking execution until done.
pub fn blocking_flush(&mut self) -> Result<(), Error> {
self.tx.blocking_flush()
}
/// Read from UART RX blocking execution until done.
pub fn blocking_read(&mut self, buffer: &mut [u8]) -> Result<(), Error> {
self.rx.blocking_read(buffer)
}
/// Check if UART is busy transmitting.
pub fn busy(&self) -> bool {
self.tx.busy()
}
/// Wait until TX is empty and send break condition.
pub async fn send_break(&mut self, bits: u32) {
self.tx.send_break(bits).await
}
/// Split the Uart into a transmitter and receiver, which is particularly
/// useful when having two tasks correlating to transmitting and receiving.
pub fn split(self) -> (UartTx<'d, T, M>, UartRx<'d, T, M>) {
(self.tx, self.rx)
}
}
impl<'d, T: Instance> Uart<'d, T, Async> {
/// Write to UART TX from the provided buffer.
pub async fn write(&mut self, buffer: &[u8]) -> Result<(), Error> {
self.tx.write(buffer).await
}
/// Read from UART RX into the provided buffer.
pub async fn read(&mut self, buffer: &mut [u8]) -> Result<(), Error> {
self.rx.read(buffer).await
}
/// Read until the buffer is full or a line break occurs.
///
/// See [`UartRx::read_to_break()`] for more details
pub async fn read_to_break<'a>(&mut self, buf: &'a mut [u8]) -> Result<usize, ReadToBreakError> {
self.rx.read_to_break(buf).await
}
}
impl<'d, T: Instance, M: Mode> embedded_hal_02::serial::Read<u8> for UartRx<'d, T, M> {
type Error = Error;
fn read(&mut self) -> Result<u8, nb::Error<Self::Error>> {
let r = T::regs();
if r.uartfr().read().rxfe() {
return Err(nb::Error::WouldBlock);
}
let dr = r.uartdr().read();
if dr.oe() {
Err(nb::Error::Other(Error::Overrun))
} else if dr.be() {
Err(nb::Error::Other(Error::Break))
} else if dr.pe() {
Err(nb::Error::Other(Error::Parity))
} else if dr.fe() {
Err(nb::Error::Other(Error::Framing))
} else {
Ok(dr.data())
}
}
}
impl<'d, T: Instance, M: Mode> embedded_hal_02::serial::Write<u8> for UartTx<'d, T, M> {
type Error = Error;
fn write(&mut self, word: u8) -> Result<(), nb::Error<Self::Error>> {
let r = T::regs();
if r.uartfr().read().txff() {
return Err(nb::Error::WouldBlock);
}
r.uartdr().write(|w| w.set_data(word));
Ok(())
}
fn flush(&mut self) -> Result<(), nb::Error<Self::Error>> {
let r = T::regs();
if !r.uartfr().read().txfe() {
return Err(nb::Error::WouldBlock);
}
Ok(())
}
}
impl<'d, T: Instance, M: Mode> embedded_hal_02::blocking::serial::Write<u8> for UartTx<'d, T, M> {
type Error = Error;
fn bwrite_all(&mut self, buffer: &[u8]) -> Result<(), Self::Error> {
self.blocking_write(buffer)
}
fn bflush(&mut self) -> Result<(), Self::Error> {