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
//! General Purpose Input / Output

use core::marker::PhantomData;

use crate::rcc::AHB4;

use crate::stm32::{EXTI, SYSCFG};

/// Extension trait to split a GPIO peripheral in independent pins and registers
pub trait GpioExt {
    /// The parts to split the GPIO into
    type Parts;

    /// Splits the GPIO block into independent pins and registers
    fn split(self, ahb4: &mut AHB4) -> Self::Parts;
}

pub struct Alternate<MODE> {
    _mode: PhantomData<MODE>,
}

/// Input mode (type state)
pub struct Input<MODE> {
    _mode: PhantomData<MODE>,
}

/// Floating input (type state)
pub struct Floating;
/// Pulled down input (type state)
pub struct PullDown;
/// Pulled up input (type state)
pub struct PullUp;

/// Output mode (type state)
pub struct Output<MODE> {
    _mode: PhantomData<MODE>,
}

/// Push pull output (type state)
pub struct PushPull;
/// Open drain output (type state)
pub struct OpenDrain;

/// Analog mode (type state)
pub struct Analog;

/// GPIO Pin speed selection
pub enum Speed {
    Low = 0,
    Medium = 1,
    High = 2,
    VeryHigh = 3,
}

pub enum Edge {
    RISING,
    FALLING,
    RISING_FALLING,
}

/// Alternate function 0 (type state)
pub struct AF0;
/// Alternate function 1 (type state)
pub struct AF1;
/// Alternate function 2 (type state)
pub struct AF2;
/// Alternate function 3 (type state)
pub struct AF3;
/// Alternate function 4 (type state)
pub struct AF4;
/// Alternate function 5 (type state)
pub struct AF5;
/// Alternate function 6 (type state)
pub struct AF6;
/// Alternate function 7 (type state)
pub struct AF7;
/// Alternate function 8 (type state)
pub struct AF8;
/// Alternate function 9 (type state)
pub struct AF9;
/// Alternate function 10 (type state)
pub struct AF10;
/// Alternate function 11 (type state)
pub struct AF11;
/// Alternate function 12 (type state)
pub struct AF12;
/// Alternate function 13 (type state)
pub struct AF13;
/// Alternate function 14 (type state)
pub struct AF14;
/// Alternate function 15 (type state)
pub struct AF15;

/// External Interrupt Pin
pub trait ExtiPin {
    fn make_interrupt_source(&mut self, syscfg: &mut SYSCFG);
    fn trigger_on_edge(&mut self, exti: &mut EXTI, level: Edge);
    fn enable_interrupt(&mut self, exti: &mut EXTI);
    fn disable_interrupt(&mut self, exti: &mut EXTI);
    fn clear_interrupt_pending_bit(&mut self, exti: &mut EXTI);
}

macro_rules! gpio {
    ($GPIOX:ident, $gpiox:ident, $iopxenr:ident, $iopxrst:ident, $PXx:ident, $extigpionr:expr, [
        $($PXi:ident: ($pxi:ident, $i:expr, $MODE:ty, $exticri:ident),)+
    ]) => {
        /// GPIO
        pub mod $gpiox {
            use core::marker::PhantomData;

            use embedded_hal::digital::v2::{InputPin, OutputPin,
                                            StatefulOutputPin, toggleable};

            use crate::rcc::AHB4;
            use crate::stm32::$GPIOX;
            use crate::stm32::{EXTI, SYSCFG};
            use super::{
                Alternate, Floating, GpioExt, Input, OpenDrain,
                Output, Speed, PullDown, PullUp, PushPull, AF0, AF1,
                AF2, AF3, AF4, AF5, AF6, AF7, AF8, AF9, AF10, AF11,
                AF12, AF13, AF14, AF15, Analog, Edge, ExtiPin, };

            use crate::Never;

            /// GPIO parts
            pub struct Parts {
                $(
                    /// Pin
                    pub $pxi: $PXi<$MODE>,
                )+
            }

            impl GpioExt for $GPIOX {
                type Parts = Parts;

                fn split(self, ahb: &mut AHB4) -> Parts {
                    ahb.enr().modify(|_, w| w.$iopxenr().set_bit());
                    ahb.rstr().modify(|_, w| w.$iopxrst().set_bit());
                    ahb.rstr().modify(|_, w| w.$iopxrst().clear_bit());

                    Parts {
                        $(
                            $pxi: $PXi { _mode: PhantomData },
                        )+
                    }
                }
            }

            /// Partially erased pin
            pub struct $PXx<MODE> {
                i: u8,
                _mode: PhantomData<MODE>,
            }

            impl<MODE> $PXx<MODE> {
                pub fn get_id(&self) -> u8 {
                    self.i
                }
            }

            impl<MODE> OutputPin for $PXx<Output<MODE>> {
                type Error = Never;

                fn set_high(&mut self) -> Result<(), Never> {
                    // NOTE(unsafe) atomic write to a stateless
                    // register
                    unsafe { (*$GPIOX::ptr()).bsrr
                               .write(|w| w.bits(1 << self.i)) }

                    Ok(())
                }

                fn set_low(&mut self) -> Result<(), Never> {
                    // NOTE(unsafe) atomic write to a stateless register
                    unsafe { (*$GPIOX::ptr()).bsrr
                               .write(|w| w.bits(1 << (self.i + 16))) }

                    Ok(())
                }
            }

            impl<MODE> StatefulOutputPin for $PXx<Output<MODE>> {
                fn is_set_high(&self) -> Result<bool, Never> {
                    self.is_set_low().map(|v| !v)
                }

                fn is_set_low(&self) -> Result<bool, Never> {
                    // NOTE(unsafe) atomic read with no side effects
                    Ok(unsafe { (*$GPIOX::ptr()).odr
                                  .read().bits() & (1 << self.i) } == 0)
                }
            }

            impl<MODE> toggleable::Default for $PXx<Output<MODE>> {}

            impl<MODE> InputPin for $PXx<Output<MODE>> {
                type Error = Never;

                fn is_high(&self) -> Result<bool, Never> {
                    self.is_low().map(|v| !v)
                }

                fn is_low(&self) -> Result<bool, Never> {
                    // NOTE(unsafe) atomic read with no side effects
                    Ok(unsafe { (*$GPIOX::ptr()).idr
                                  .read().bits() & (1 << self.i) } == 0)
                }
            }

            impl<MODE> InputPin for $PXx<Input<MODE>> {
                type Error = Never;

                fn is_high(&self) -> Result<bool, Never> {
                    self.is_low().map(|v| !v)
                }

                fn is_low(&self) -> Result<bool, Never> {
                    // NOTE(unsafe) atomic read with no side effects
                    Ok(unsafe { (*$GPIOX::ptr()).idr
                                  .read().bits() & (1 << self.i) } == 0)
                }
            }

            impl<MODE> ExtiPin for $PXx<Input<MODE>> {
                /// Make corresponding EXTI line sensitive to this pin
                fn make_interrupt_source(&mut self, syscfg: &mut SYSCFG) {
                    let offset = 4 * (self.i % 4);
                    match self.i {
                        0..=3 => {
                            syscfg.exticr1.modify(|r, w| unsafe {
                                w.bits((r.bits() & !(0xf << offset)) | ($extigpionr << offset))
                            });
                        },
                        4..=7 => {
                            syscfg.exticr2.modify(|r, w| unsafe {
                                w.bits((r.bits() & !(0xf << offset)) | ($extigpionr << offset))
                            });
                        },
                        8..=11 => {
                            syscfg.exticr3.modify(|r, w| unsafe {
                                w.bits((r.bits() & !(0xf << offset)) | ($extigpionr << offset))
                            });
                        },
                        12..=15 => {
                            syscfg.exticr4.modify(|r, w| unsafe {
                                w.bits((r.bits() & !(0xf << offset)) | ($extigpionr << offset))
                            });
                        },
                        _ => {}
                    }
                }

                /// Generate interrupt on rising edge, falling edge or both
                fn trigger_on_edge(&mut self, exti: &mut EXTI, edge: Edge) {
                    match edge {
                        Edge::RISING => {
                            exti.rtsr1.modify(|r, w| unsafe { w.bits(r.bits() | (1 << self.i)) });
                            exti.ftsr1.modify(|r, w| unsafe { w.bits(r.bits() & !(1 << self.i)) });
                        },
                        Edge::FALLING => {
                            exti.ftsr1.modify(|r, w| unsafe { w.bits(r.bits() | (1 << self.i)) });
                            exti.rtsr1.modify(|r, w| unsafe { w.bits(r.bits() & !(1 << self.i)) });
                        },
                        Edge::RISING_FALLING => {
                            exti.rtsr1.modify(|r, w| unsafe { w.bits(r.bits() | (1 << self.i)) });
                            exti.ftsr1.modify(|r, w| unsafe { w.bits(r.bits() | (1 << self.i)) });
                        }
                    }
                }

                /// Enable external interrupts from this pin.
                fn enable_interrupt(&mut self, exti: &mut EXTI) {
                    exti.cpuimr1.modify(|r, w| unsafe { w.bits(r.bits() | (1 << self.i)) });
                }

                /// Disable external interrupts from this pin
                fn disable_interrupt(&mut self, exti: &mut EXTI) {
                    exti.cpuimr1.modify(|r, w| unsafe { w.bits(r.bits() & !(1 << self.i)) });
                }

                /// Clear the interrupt pending bit for this pin
                fn clear_interrupt_pending_bit(&mut self, exti: &mut EXTI) {
                    exti.cpupr1.modify(|r, w| unsafe { w.bits(r.bits() | (1 << self.i)) });
                }
            }

            fn _set_alternate_mode (index: usize, mode: u32)
            {
                let offset = 2 * index;
                let offset2 = 4 * index;
                unsafe {
                    if offset2 < 32 {
                        &(*$GPIOX::ptr()).afrl.modify(|r, w| {
                            w.bits((r.bits() & !(0b1111 << offset2)) | (mode << offset2))
                        });
                    } else {
                        let offset2 = offset2 - 32;
                        &(*$GPIOX::ptr()).afrh.modify(|r, w| {
                            w.bits((r.bits() & !(0b1111 << offset2)) | (mode << offset2))
                        });
                    }
                    &(*$GPIOX::ptr()).moder.modify(|r, w| {
                        w.bits((r.bits() & !(0b11 << offset)) | (0b10 << offset))
                    });
                }
            }

            $(
                /// Pin
                pub struct $PXi<MODE> {
                    _mode: PhantomData<MODE>,
                }

                impl<MODE> $PXi<MODE> {
                    /// Configures the pin to operate in AF0 mode
                    pub fn into_alternate_af0(self) -> $PXi<Alternate<AF0>> {
                        _set_alternate_mode($i, 0);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF1 mode
                    pub fn into_alternate_af1(self) -> $PXi<Alternate<AF1>> {
                        _set_alternate_mode($i, 1);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF2 mode
                    pub fn into_alternate_af2(self) -> $PXi<Alternate<AF2>> {
                        _set_alternate_mode($i, 2);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF3 mode
                    pub fn into_alternate_af3(self) -> $PXi<Alternate<AF3>> {
                        _set_alternate_mode($i, 3);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF4 mode
                    pub fn into_alternate_af4(self) -> $PXi<Alternate<AF4>> {
                        _set_alternate_mode($i, 4);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF5 mode
                    pub fn into_alternate_af5(self) -> $PXi<Alternate<AF5>> {
                        _set_alternate_mode($i, 5);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF6 mode
                    pub fn into_alternate_af6(self) -> $PXi<Alternate<AF6>> {
                        _set_alternate_mode($i, 6);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF7 mode
                    pub fn into_alternate_af7(self) -> $PXi<Alternate<AF7>> {
                        _set_alternate_mode($i, 7);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF8 mode
                    pub fn into_alternate_af8(self) -> $PXi<Alternate<AF8>> {
                        _set_alternate_mode($i, 8);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF9 mode
                    pub fn into_alternate_af9(self) -> $PXi<Alternate<AF9>> {
                        _set_alternate_mode($i, 9);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF10 mode
                    pub fn into_alternate_af10(self) -> $PXi<Alternate<AF10>> {
                        _set_alternate_mode($i, 10);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF11 mode
                    pub fn into_alternate_af11(self) -> $PXi<Alternate<AF11>> {
                        _set_alternate_mode($i, 11);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF12 mode
                    pub fn into_alternate_af12(self) -> $PXi<Alternate<AF12>> {
                        _set_alternate_mode($i, 12);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF13 mode
                    pub fn into_alternate_af13(self) -> $PXi<Alternate<AF13>> {
                        _set_alternate_mode($i, 13);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF14 mode
                    pub fn into_alternate_af14(self) -> $PXi<Alternate<AF14>> {
                        _set_alternate_mode($i, 14);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate in AF15 mode
                    pub fn into_alternate_af15(self) -> $PXi<Alternate<AF15>> {
                        _set_alternate_mode($i, 15);
                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate as a floating
                    /// input pin
                    pub fn into_floating_input(self) -> $PXi<Input<Floating>> {
                        let offset = 2 * $i;
                        unsafe {
                            &(*$GPIOX::ptr()).pupdr.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | (0b00 << offset))
                            });
                            &(*$GPIOX::ptr()).moder.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | (0b00 << offset))
                            })
                        };

                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate as a pulled down
                    /// input pin
                    pub fn into_pull_down_input(self) -> $PXi<Input<PullDown>> {
                        let offset = 2 * $i;
                        unsafe {
                            &(*$GPIOX::ptr()).pupdr.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | (0b10 << offset))
                            });
                            &(*$GPIOX::ptr()).moder.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | (0b00 << offset))
                            })
                        };

                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate as a pulled up
                    /// input pin
                    pub fn into_pull_up_input(self) -> $PXi<Input<PullUp>> {
                        let offset = 2 * $i;
                        unsafe {
                            &(*$GPIOX::ptr()).pupdr.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | (0b01 << offset))
                            });
                            &(*$GPIOX::ptr()).moder.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | (0b00 << offset))
                            }
                        )};

                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate as an open drain
                    /// output pin
                    pub fn into_open_drain_output(self) -> $PXi<Output<OpenDrain>> {
                        let offset = 2 * $i;
                        unsafe {
                            &(*$GPIOX::ptr()).pupdr.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | (0b00 << offset))
                            });
                            &(*$GPIOX::ptr()).otyper.modify(|r, w| {
                                w.bits(r.bits() | (0b1 << $i))
                            });
                            &(*$GPIOX::ptr()).moder.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | (0b01 << offset))
                            })
                        };

                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate as an push pull
                    /// output pin
                    pub fn into_push_pull_output(self) -> $PXi<Output<PushPull>> {
                        let offset = 2 * $i;

                        unsafe {
                            &(*$GPIOX::ptr()).pupdr.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | (0b00 << offset))
                            });
                            &(*$GPIOX::ptr()).otyper.modify(|r, w| {
                                w.bits(r.bits() & !(0b1 << $i))
                            });
                            &(*$GPIOX::ptr()).moder.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | (0b01 << offset))
                            })
                        };

                        $PXi { _mode: PhantomData }
                    }

                    /// Configures the pin to operate as an analog
                    /// input pin
                    pub fn into_analog(self) -> $PXi<Analog> {
                        let offset = 2 * $i;

                        unsafe {
                            &(*$GPIOX::ptr()).pupdr.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | (0b00 << offset))
                            });
                            &(*$GPIOX::ptr()).moder.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | (0b11 << offset))
                            }
                        )};

                        $PXi { _mode: PhantomData }
                    }
                }

                impl<MODE> $PXi<Output<MODE>> {
                    /// Set pin speed
                    pub fn set_speed(self, speed: Speed) -> Self {
                        let offset = 2 * $i;

                        unsafe {
                            &(*$GPIOX::ptr()).ospeedr.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | ((speed as u32) << offset))
                            })
                        };

                        self
                    }
                }

                impl $PXi<Output<OpenDrain>> {
                    /// Enables / disables the internal pull up
                    pub fn internal_pull_up(&mut self, on: bool) {
                        let offset = 2 * $i;
                        let value = if on { 0b01 } else { 0b00 };
                        unsafe {
                            &(*$GPIOX::ptr()).pupdr.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | (value << offset))
                            })
                        };
                    }
                }

                impl<MODE> $PXi<Alternate<MODE>> {
                    /// Set pin speed
                    pub fn set_speed(self, speed: Speed) -> Self {
                        let offset = 2 * $i;

                        unsafe {
                            &(*$GPIOX::ptr()).ospeedr.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | ((speed as u32) << offset))
                            })
                        };

                        self
                    }

                    /// Enables / disables the internal pull up
                    pub fn internal_pull_up(self, on: bool) -> Self {
                        let offset = 2 * $i;
                        let value = if on { 0b01 } else { 0b00 };
                        unsafe {
                            &(*$GPIOX::ptr()).pupdr.modify(|r, w| {
                                w.bits((r.bits() & !(0b11 << offset)) | (value << offset))
                            })
                        };

                        self
                    }
                }

                impl<MODE> $PXi<Alternate<MODE>> {
                    /// Turns pin alternate configuration pin into
                    /// open drain
                    pub fn set_open_drain(self) -> Self {
                        let offset = $i;
                        unsafe {
                            &(*$GPIOX::ptr()).otyper.modify(|r, w| {
                                w.bits(r.bits() | (1 << offset))
                            })
                        };

                        self
                    }
                }

                impl<MODE> $PXi<MODE> {
                    /// Erases the pin number from the type
                    ///
                    /// This is useful when you want to collect the
                    /// pins into an array where you need all the
                    /// elements to have the same type
                    pub fn downgrade(self) -> $PXx<MODE> {
                        $PXx {
                            i: $i,
                            _mode: self._mode,
                        }
                    }
                }

                impl<MODE> OutputPin for $PXi<Output<MODE>> {
                    type Error = Never;

                    fn set_high(&mut self) -> Result<(), Never> {
                        // NOTE(unsafe) atomic write to a stateless
                        // register
                        unsafe { (*$GPIOX::ptr()).bsrr
                                   .write(|w| w.bits(1 << $i)) }

                        Ok(())
                    }

                    fn set_low(&mut self) -> Result<(), Never> {
                        // NOTE(unsafe) atomic write to a stateless
                        // register
                        unsafe { (*$GPIOX::ptr()).bsrr
                                   .write(|w| w.bits(1 << ($i + 16))) }

                        Ok(())
                    }
                }

                impl<MODE> StatefulOutputPin for $PXi<Output<MODE>> {
                    fn is_set_high(&self) -> Result<bool, Never> {
                        self.is_set_low().map(|v| !v)
                    }

                    fn is_set_low(&self) -> Result<bool, Never> {
                        // NOTE(unsafe) atomic read with no side effects
                        Ok(unsafe { (*$GPIOX::ptr()).odr
                                      .read().bits() & (1 << $i) } == 0)
                    }
                }

                impl<MODE> toggleable::Default for $PXi<Output<MODE>> {}

                impl<MODE> InputPin for $PXi<Output<MODE>> {
                    type Error = Never;

                    fn is_high(&self) -> Result<bool, Never> {
                        self.is_low().map(|v| !v)
                    }

                    fn is_low(&self) -> Result<bool, Never> {
                        // NOTE(unsafe) atomic read with no side effects
                        Ok(unsafe { (*$GPIOX::ptr()).idr
                                      .read().bits() & (1 << $i) } == 0)
                    }
                }

                impl<MODE> InputPin for $PXi<Input<MODE>> {
                    type Error = Never;

                    fn is_high(&self) -> Result<bool, Never> {
                        self.is_low().map(|v| !v)
                    }

                    fn is_low(&self) -> Result<bool, Never> {
                        // NOTE(unsafe) atomic read with no side effects
                        Ok(unsafe { (*$GPIOX::ptr()).idr
                                      .read().bits() & (1 << $i) } == 0)
                    }
                }

                impl<MODE> ExtiPin for $PXi<Input<MODE>> {
                    /// Configure EXTI Line $i to trigger from this pin.
                    fn make_interrupt_source(&mut self, syscfg: &mut SYSCFG) {
                        let offset = 4 * ($i % 4);
                        syscfg.$exticri.modify(|r, w| unsafe {
                            let mut exticr = r.bits();
                            exticr = (exticr & !(0xf << offset)) | ($extigpionr << offset);
                            w.bits(exticr)
                        });
                    }

                    /// Generate interrupt on rising edge, falling edge or both
                    fn trigger_on_edge(&mut self, exti: &mut EXTI, edge: Edge) {
                        match edge {
                            Edge::RISING => {
                                exti.rtsr1.modify(|r, w| unsafe { w.bits(r.bits() | (1 << $i)) });
                                exti.ftsr1.modify(|r, w| unsafe { w.bits(r.bits() & !(1 << $i)) });
                            },
                            Edge::FALLING => {
                                exti.ftsr1.modify(|r, w| unsafe { w.bits(r.bits() | (1 << $i)) });
                                exti.rtsr1.modify(|r, w| unsafe { w.bits(r.bits() & !(1 << $i)) });
                            },
                            Edge::RISING_FALLING => {
                                exti.rtsr1.modify(|r, w| unsafe { w.bits(r.bits() | (1 << $i)) });
                                exti.ftsr1.modify(|r, w| unsafe { w.bits(r.bits() | (1 << $i)) });
                            }
                        }
                    }

                    /// Enable external interrupts from this pin.
                    fn enable_interrupt(&mut self, exti: &mut EXTI) {
                        exti.cpuimr1.modify(|r, w| unsafe { w.bits(r.bits() | (1 << $i)) });
                    }

                    /// Disable external interrupts from this pin
                    fn disable_interrupt(&mut self, exti: &mut EXTI) {
                        exti.cpuimr1.modify(|r, w| unsafe { w.bits(r.bits() & !(1 << $i)) });
                    }

                    /// Clear the interrupt pending bit for this pin
                    fn clear_interrupt_pending_bit(&mut self, exti: &mut EXTI) {
                        exti.cpupr1.modify(|r, w| unsafe { w.bits(r.bits() | (1 << $i)) });
                    }
                }

            )+
        }
    }
}

gpio!(GPIOA, gpioa, gpioaen, gpioarst, PA, 0, [
    PA0: (pa0, 0, Input<Floating>, exticr1),
    PA1: (pa1, 1, Input<Floating>, exticr1),
    PA2: (pa2, 2, Input<Floating>, exticr1),
    PA3: (pa3, 3, Input<Floating>, exticr1),
    PA4: (pa4, 4, Input<Floating>, exticr2),
    PA5: (pa5, 5, Input<Floating>, exticr2),
    PA6: (pa6, 6, Input<Floating>, exticr2),
    PA7: (pa7, 7, Input<Floating>, exticr2),
    PA8: (pa8, 8, Input<Floating>, exticr3),
    PA9: (pa9, 9, Input<Floating>, exticr3),
    PA10: (pa10, 10, Input<Floating>, exticr3),
    PA11: (pa11, 11, Input<Floating>, exticr3),
    PA12: (pa12, 12, Input<Floating>, exticr4),
    PA13: (pa13, 13, Input<Floating>, exticr4),
    PA14: (pa14, 14, Input<Floating>, exticr4),
    PA15: (pa15, 15, Input<Floating>, exticr4),
]);

gpio!(GPIOB, gpiob, gpioben, gpiobrst, PB, 1, [
    PB0: (pb0, 0, Input<Floating>, exticr1),
    PB1: (pb1, 1, Input<Floating>, exticr1),
    PB2: (pb2, 2, Input<Floating>, exticr1),
    PB3: (pb3, 3, Input<Floating>, exticr1),
    PB4: (pb4, 4, Input<Floating>, exticr2),
    PB5: (pb5, 5, Input<Floating>, exticr2),
    PB6: (pb6, 6, Input<Floating>, exticr2),
    PB7: (pb7, 7, Input<Floating>, exticr2),
    PB8: (pb8, 8, Input<Floating>, exticr3),
    PB9: (pb9, 9, Input<Floating>, exticr3),
    PB10: (pb10, 10, Input<Floating>, exticr3),
    PB11: (pb11, 11, Input<Floating>, exticr3),
    PB12: (pb12, 12, Input<Floating>, exticr4),
    PB13: (pb13, 13, Input<Floating>, exticr4),
    PB14: (pb14, 14, Input<Floating>, exticr4),
    PB15: (pb15, 15, Input<Floating>, exticr4),
]);

gpio!(GPIOC, gpioc, gpiocen, gpiocrst, PC, 2, [
    PC0: (pc0, 0, Input<Floating>, exticr1),
    PC1: (pc1, 1, Input<Floating>, exticr1),
    PC2: (pc2, 2, Input<Floating>, exticr1),
    PC3: (pc3, 3, Input<Floating>, exticr1),
    PC4: (pc4, 4, Input<Floating>, exticr2),
    PC5: (pc5, 5, Input<Floating>, exticr2),
    PC6: (pc6, 6, Input<Floating>, exticr2),
    PC7: (pc7, 7, Input<Floating>, exticr2),
    PC8: (pc8, 8, Input<Floating>, exticr3),
    PC9: (pc9, 9, Input<Floating>, exticr3),
    PC10: (pc10, 10, Input<Floating>, exticr3),
    PC11: (pc11, 11, Input<Floating>, exticr3),
    PC12: (pc12, 12, Input<Floating>, exticr4),
    PC13: (pc13, 13, Input<Floating>, exticr4),
    PC14: (pc14, 14, Input<Floating>, exticr4),
    PC15: (pc15, 15, Input<Floating>, exticr4),
]);

gpio!(GPIOD, gpiod, gpioden, gpiodrst, PD, 3, [
    PD0: (pd0, 0, Input<Floating>, exticr1),
    PD1: (pd1, 1, Input<Floating>, exticr1),
    PD2: (pd2, 2, Input<Floating>, exticr1),
    PD3: (pd3, 3, Input<Floating>, exticr1),
    PD4: (pd4, 4, Input<Floating>, exticr2),
    PD5: (pd5, 5, Input<Floating>, exticr2),
    PD6: (pd6, 6, Input<Floating>, exticr2),
    PD7: (pd7, 7, Input<Floating>, exticr2),
    PD8: (pd8, 8, Input<Floating>, exticr3),
    PD9: (pd9, 9, Input<Floating>, exticr3),
    PD10: (pd10, 10, Input<Floating>, exticr3),
    PD11: (pd11, 11, Input<Floating>, exticr3),
    PD12: (pd12, 12, Input<Floating>, exticr4),
    PD13: (pd13, 13, Input<Floating>, exticr4),
    PD14: (pd14, 14, Input<Floating>, exticr4),
    PD15: (pd15, 15, Input<Floating>, exticr4),
]);

gpio!(GPIOE, gpioe, gpioeen, gpioerst, PE, 4, [
    PE0: (pe0, 0, Input<Floating>, exticr1),
    PE1: (pe1, 1, Input<Floating>, exticr1),
    PE2: (pe2, 2, Input<Floating>, exticr1),
    PE3: (pe3, 3, Input<Floating>, exticr1),
    PE4: (pe4, 4, Input<Floating>, exticr2),
    PE5: (pe5, 5, Input<Floating>, exticr2),
    PE6: (pe6, 6, Input<Floating>, exticr2),
    PE7: (pe7, 7, Input<Floating>, exticr2),
    PE8: (pe8, 8, Input<Floating>, exticr3),
    PE9: (pe9, 9, Input<Floating>, exticr3),
    PE10: (pe10, 10, Input<Floating>, exticr3),
    PE11: (pe11, 11, Input<Floating>, exticr3),
    PE12: (pe12, 12, Input<Floating>, exticr4),
    PE13: (pe13, 13, Input<Floating>, exticr4),
    PE14: (pe14, 14, Input<Floating>, exticr4),
    PE15: (pe15, 15, Input<Floating>, exticr4),
]);

gpio!(GPIOF, gpiof, gpiofen, gpiofrst, PF, 5, [
    PF0: (pf0, 0, Input<Floating>, exticr1),
    PF1: (pf1, 1, Input<Floating>, exticr1),
    PF2: (pf2, 2, Input<Floating>, exticr1),
    PF3: (pf3, 3, Input<Floating>, exticr1),
    PF4: (pf4, 4, Input<Floating>, exticr2),
    PF5: (pf5, 5, Input<Floating>, exticr2),
    PF6: (pf6, 6, Input<Floating>, exticr2),
    PF7: (ph7, 7, Input<Floating>, exticr2),
    PF8: (pf8, 8, Input<Floating>, exticr3),
    PF9: (pf9, 9, Input<Floating>, exticr3),
    PF10: (pf10, 10, Input<Floating>, exticr3),
    PF11: (pf11, 11, Input<Floating>, exticr3),
    PF12: (pf12, 12, Input<Floating>, exticr4),
    PF13: (pf13, 13, Input<Floating>, exticr4),
    PF14: (pf14, 14, Input<Floating>, exticr4),
    PF15: (pf15, 15, Input<Floating>, exticr4),
]);

gpio!(GPIOG, gpiog, gpiogen, gpiogrst, PG, 6, [
    PG0: (pg0, 0, Input<Floating>, exticr1),
    PG1: (pg1, 1, Input<Floating>, exticr1),
    PG2: (pg2, 2, Input<Floating>, exticr1),
    PG3: (pg3, 3, Input<Floating>, exticr1),
    PG4: (pg4, 4, Input<Floating>, exticr2),
    PG5: (pg5, 5, Input<Floating>, exticr2),
    PG6: (pg6, 6, Input<Floating>, exticr2),
    PG7: (pg7, 7, Input<Floating>, exticr2),
    PG8: (pg8, 8, Input<Floating>, exticr3),
    PG9: (pg9, 9, Input<Floating>, exticr3),
    PG10: (pg10, 10, Input<Floating>, exticr3),
    PG11: (pg11, 11, Input<Floating>, exticr3),
    PG12: (pg12, 12, Input<Floating>, exticr4),
    PG13: (pg13, 13, Input<Floating>, exticr4),
    PG14: (pg14, 14, Input<Floating>, exticr4),
    PG15: (pg15, 15, Input<Floating>, exticr4),
]);

gpio!(GPIOH, gpioh, gpiohen, gpiohrst, PH, 7, [
    PH0: (ph0, 0, Input<Floating>, exticr1),
    PH1: (ph1, 1, Input<Floating>, exticr1),
    PH2: (ph2, 2, Input<Floating>, exticr1),
    PH3: (ph3, 3, Input<Floating>, exticr1),
    PH4: (ph4, 4, Input<Floating>, exticr2),
    PH5: (ph5, 5, Input<Floating>, exticr2),
    PH6: (ph6, 6, Input<Floating>, exticr2),
    PH7: (ph7, 7, Input<Floating>, exticr2),
    PH8: (ph8, 8, Input<Floating>, exticr3),
    PH9: (ph9, 9, Input<Floating>, exticr3),
    PH10: (ph10, 10, Input<Floating>, exticr3),
    PH11: (ph11, 11, Input<Floating>, exticr3),
    PH12: (ph12, 12, Input<Floating>, exticr4),
    PH13: (ph13, 13, Input<Floating>, exticr4),
    PH14: (ph14, 14, Input<Floating>, exticr4),
    PH15: (ph15, 15, Input<Floating>, exticr4),
]);

gpio!(GPIOI, gpioi, gpioien, gpioirst, PI, 8, [
    PI0: (pi0, 0, Input<Floating>, exticr1),
    PI1: (pi1, 1, Input<Floating>, exticr1),
    PI2: (pi2, 2, Input<Floating>, exticr1),
    PI3: (pi3, 3, Input<Floating>, exticr1),
    PI4: (pi4, 4, Input<Floating>, exticr2),
    PI5: (pi5, 5, Input<Floating>, exticr2),
    PI6: (pi6, 6, Input<Floating>, exticr2),
    PI7: (pi7, 7, Input<Floating>, exticr2),
    PI8: (pi8, 8, Input<Floating>, exticr3),
    PI9: (pi9, 9, Input<Floating>, exticr3),
    PI10: (pi10, 10, Input<Floating>, exticr3),
    PI11: (pi11, 11, Input<Floating>, exticr3),
    PI12: (pi12, 12, Input<Floating>, exticr4),
    PI13: (pi13, 13, Input<Floating>, exticr4),
    PI14: (pi14, 14, Input<Floating>, exticr4),
    PI15: (pi15, 15, Input<Floating>, exticr4),
]);

gpio!(GPIOJ, gpioj, gpiojen, gpiojrst, PJ, 9, [
    PJ0: (pj0, 0, Input<Floating>, exticr1),
    PJ1: (pj1, 1, Input<Floating>, exticr1),
    PJ2: (pj2, 2, Input<Floating>, exticr1),
    PJ3: (pj3, 3, Input<Floating>, exticr1),
    PJ4: (pj4, 4, Input<Floating>, exticr2),
    PJ5: (pj5, 5, Input<Floating>, exticr2),
    PJ6: (pj6, 6, Input<Floating>, exticr2),
    PJ7: (pj7, 7, Input<Floating>, exticr2),
    PJ8: (pj8, 8, Input<Floating>, exticr3),
    PJ9: (pj9, 9, Input<Floating>, exticr3),
    PJ10: (pj10, 10, Input<Floating>, exticr3),
    PJ11: (pj11, 11, Input<Floating>, exticr3),
    PJ12: (pj12, 12, Input<Floating>, exticr4),
    PJ13: (pj13, 13, Input<Floating>, exticr4),
    PJ14: (pj14, 14, Input<Floating>, exticr4),
    PJ15: (pj15, 15, Input<Floating>, exticr4),
]);

gpio!(GPIOK, gpiok, gpioken, gpiokrst, PK, 10, [
    PK0: (pk0, 0, Input<Floating>, exticr1),
    PK1: (pk1, 1, Input<Floating>, exticr1),
    PK2: (pk2, 2, Input<Floating>, exticr1),
    PK3: (pk3, 3, Input<Floating>, exticr1),
    PK4: (pk4, 4, Input<Floating>, exticr2),
    PK5: (pk5, 5, Input<Floating>, exticr2),
    PK6: (pk6, 6, Input<Floating>, exticr2),
    PK7: (pk7, 7, Input<Floating>, exticr2),
    PK8: (pk8, 8, Input<Floating>, exticr3),
    PK9: (pk9, 9, Input<Floating>, exticr3),
    PK10: (pk10, 10, Input<Floating>, exticr3),
    PK11: (pk11, 11, Input<Floating>, exticr3),
    PK12: (pk12, 12, Input<Floating>, exticr4),
    PK13: (pk13, 13, Input<Floating>, exticr4),
    PK14: (pk14, 14, Input<Floating>, exticr4),
    PK15: (pk15, 15, Input<Floating>, exticr4),
]);