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Fix RP2xxx I2SOut reversed channels #10250

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Merged
merged 5 commits into from
Apr 21, 2025
Merged

Fix RP2xxx I2SOut reversed channels #10250

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fdc4abf
uniform swap now
dhalbert Apr 14, 2025
122ea2f
raspberrypi I2SOut: fix flipped stereo channels
dhalbert Apr 14, 2025
1e29c6a
address review
dhalbert Apr 14, 2025
0ddaf75
add README.pio, mostly to force another build
dhalbert Apr 15, 2025
6b99053
Explicate .pio file usage
dhalbert Apr 15, 2025
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238 changes: 134 additions & 104 deletions ports/raspberrypi/common-hal/audiobusio/I2SOut.c
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Original file line number Diff line number Diff line change
Expand Up @@ -19,122 +19,152 @@
#include "bindings/rp2pio/StateMachine.h"

const uint16_t i2s_program[] = {
// ; Load the next set of samples
// ; /--- LRCLK
// ; |/-- BCLK
// ; ||
// pull noblock side 0b01 ; Loads OSR with the next FIFO value or X
0x8880,
// mov x osr side 0b01 ; Save the new value in case we need it again
0xa827,
// set y 14 side 0b01
0xe84e,
// bitloop1:
// out pins 1 side 0b00 [2]
0x6201,
// jmp y-- bitloop1 side 0b01 [2]
0x0a83,
// out pins 1 side 0b10 [2]
0x7201,
// set y 14 side 0b11 [2]
0xfa4e,
// bitloop0:
// out pins 1 side 0b10 [2]
0x7201,
// jmp y-- bitloop0 side 0b11 [2]
0x1a87,
// out pins 1 side 0b00 [2]
0x6201

/* From i2s.pio:

.program i2s
.side_set 2

; Load the next set of samples
; /--- LRCLK
; |/-- BCLK
; ||
pull noblock side 0b11 ; Loads OSR with the next FIFO value or X
mov x osr side 0b11 ; Save the new value in case we need it again
set y 14 side 0b11
bitloop1:
out pins 1 side 0b10 [2] ; Right channel first
jmp y-- bitloop1 side 0b11 [2]
out pins 1 side 0b00 [2]
set y 14 side 0b01 [2]
bitloop0:
out pins 1 side 0b00 [2] ; Then left channel
jmp y-- bitloop0 side 0b01 [2]
out pins 1 side 0b10 [2]
*/
// Above assembled with pioasm.
0x9880, // 0: pull noblock side 3
0xb827, // 1: mov x, osr side 3
0xf84e, // 2: set y, 14 side 3
0x7201, // 3: out pins, 1 side 2 [2]
0x1a83, // 4: jmp y--, 3 side 3 [2]
0x6201, // 5: out pins, 1 side 0 [2]
0xea4e, // 6: set y, 14 side 1 [2]
0x6201, // 7: out pins, 1 side 0 [2]
0x0a87, // 8: jmp y--, 7 side 1 [2]
0x7201, // 9: out pins, 1 side 2 [2]
};


const uint16_t i2s_program_left_justified[] = {
// ; Load the next set of samples
// ; /--- LRCLK
// ; |/-- BCLK
// ; ||
// pull noblock side 0b11 ; Loads OSR with the next FIFO value or X
0x9880,
// mov x osr side 0b11 ; Save the new value in case we need it again
0xb827,
// set y 14 side 0b11
0xf84e,
// bitloop1:
// out pins 1 side 0b00 [2]
0x6201,
// jmp y-- bitloop1 side 0b01 [2]
0x0a83,
// out pins 1 side 0b00 [2]
0x6201,
// set y 14 side 0b01 [2]
0xea4e,
// bitloop0:
// out pins 1 side 0b10 [2]
0x7201,
// jmp y-- bitloop0 side 0b11 [2]
0x1a87,
// out pins 1 side 0b10 [2]
0x7201
/* From i2s_left.pio:

.program i2s
.side_set 2

; Load the next set of samples
; /--- LRCLK
; |/-- BCLK
; ||
pull noblock side 0b01 ; Loads OSR with the next FIFO value or X
mov x osr side 0b01 ; Save the new value in case we need it again
set y 14 side 0b01
bitloop1:
out pins 1 side 0b10 [2] ; Right channel first
jmp y-- bitloop1 side 0b11 [2]
out pins 1 side 0b10 [2]
set y 14 side 0b11 [2]
bitloop0:
out pins 1 side 0b00 [2] ; Then left channel
jmp y-- bitloop0 side 0b01 [2]
out pins 1 side 0b00 [2]
*/
// Above assembled with pioasm.
0x8880, // 0: pull noblock side 1
0xa827, // 1: mov x, osr side 1
0xe84e, // 2: set y, 14 side 1
0x7201, // 3: out pins, 1 side 2 [2]
0x1a83, // 4: jmp y--, 3 side 3 [2]
0x7201, // 5: out pins, 1 side 2 [2]
0xfa4e, // 6: set y, 14 side 3 [2]
0x6201, // 7: out pins, 1 side 0 [2]
0x0a87, // 8: jmp y--, 7 side 1 [2]
0x6201, // 9: out pins, 1 side 0 [2]
};

// Another version of i2s_program with the LRCLC and BCLK pin swapped
const uint16_t i2s_program_swap[] = {
// ; Load the next set of samples
// ; /--- BCLK
// ; |/-- LRCLK
// ; ||
// pull noblock side 0b11 ; Loads OSR with the next FIFO value or X
0x9880,
// mov x osr side 0b11 ; Save the new value in case we need it again
0xb827,
// set y 14 side 0b11
0xf84e,
// bitloop1:
// out pins 1 side 0b01 [2]
0x6a01,
// jmp y-- bitloop1 side 0b11 [2]
0x1a83,
// out pins 1 side 0b00 [2]
0x6201,
// set y 14 side 0b10 [2]
0xf24e,
// bitloop0:
// out pins 1 side 0b00 [2]
0x6201,
// jmp y-- bitloop0 side 0b10 [2]
0x1287,
// out pins 1 side 0b01 [2]
0x6a01
/* From i2s_swap.pio:

.program i2s
.side_set 2

; Load the next set of samples
; /--- BCLK
; |/-- LRCLK
; ||
pull noblock side 0b11 ; Loads OSR with the next FIFO value or X
mov x osr side 0b11 ; Save the new value in case we need it again
set y 14 side 0b11
bitloop1:
out pins 1 side 0b01 [2] ; Right channel first
jmp y-- bitloop1 side 0b11 [2]
out pins 1 side 0b00 [2]
set y 14 side 0b10 [2]
bitloop0:
out pins 1 side 0b00 [2] ; Then left channel
jmp y-- bitloop0 side 0b10 [2]
out pins 1 side 0b01 [2]
*/
// Above assembled with pioasm.
0x9880, // 0: pull noblock side 3
0xb827, // 1: mov x, osr side 3
0xf84e, // 2: set y, 14 side 3
0x6a01, // 3: out pins, 1 side 1 [2]
0x1a83, // 4: jmp y--, 3 side 3 [2]
0x6201, // 5: out pins, 1 side 0 [2]
0xf24e, // 6: set y, 14 side 2 [2]
0x6201, // 7: out pins, 1 side 0 [2]
0x1287, // 8: jmp y--, 7 side 2 [2]
0x6a01, // 9: out pins, 1 side 1 [2]
};

// Another version of i2s_program_left_justified with the LRCLC and BCLK pin
// swapped.
const uint16_t i2s_program_left_justified_swap[] = {
// ; Load the next set of samples
// ; /--- BCLK
// ; |/-- LRCLK
// ; ||
// pull noblock side 0b11 ; Loads OSR with the next FIFO value or X
0x9880,
// mov x osr side 0b11 ; Save the new value in case we need it again
0xb827,
// set y 14 side 0b11
0xf84e,
// bitloop1:
// out pins 1 side 0b00 [2]
0x6201,
// jmp y-- bitloop1 side 0b10 [2]
0x1283,
// out pins 1 side 0b00 [2]
0x6201,
// set y 14 side 0b10 [2]
0xf24e,
// bitloop0:
// out pins 1 side 0b01 [2]
0x6a01,
// jmp y-- bitloop0 side 0b11 [2]
0x1a87,
// out pins 1 side 0b01 [2]
0x6a01
/* From i2s_swap_left.pio:

.program i2s
.side_set 2

; Load the next set of samples
; /--- BCLK
; |/-- LRCLK
; ||
pull noblock side 0b10 ; Loads OSR with the next FIFO value or X
mov x osr side 0b10 ; Save the new value in case we need it again
set y 14 side 0b10
bitloop1:
out pins 1 side 0b01 [2] ; Right channel first
jmp y-- bitloop1 side 0b11 [2]
out pins 1 side 0b01 [2]
set y 14 side 0b11 [2]
bitloop0:
out pins 1 side 0b00 [2] ; Then left channel
jmp y-- bitloop0 side 0b10 [2]
out pins 1 side 0b00 [2]
*/
// Above assembled with pioasm.
0x9080, // 0: pull noblock side 2
0xb027, // 1: mov x, osr side 2
0xf04e, // 2: set y, 14 side 2
0x6a01, // 3: out pins, 1 side 1 [2]
0x1a83, // 4: jmp y--, 3 side 3 [2]
0x6a01, // 5: out pins, 1 side 1 [2]
0xfa4e, // 6: set y, 14 side 3 [2]
0x6201, // 7: out pins, 1 side 0 [2]
0x1287, // 8: jmp y--, 7 side 2 [2]
0x6201, // 9: out pins, 1 side 0 [2]
};

void i2sout_reset(void) {
Expand Down
7 changes: 7 additions & 0 deletions ports/raspberrypi/common-hal/audiobusio/README.pio
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Original file line number Diff line number Diff line change
@@ -0,0 +1,7 @@
.pio files right now are compiled by hand with pico-sdk/tools/pioasm and inserted into I2SOut.c

i2s.pio regular pin order, not left_justified
i2s_left.pio regular pin order, left_justified

i2s_swap.pio swapped pin order, not left_justified
i2s_swap_left.pio swapped pin order, left_justified
25 changes: 25 additions & 0 deletions ports/raspberrypi/common-hal/audiobusio/i2s.pio
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Original file line number Diff line number Diff line change
@@ -0,0 +1,25 @@
; This file is part of the CircuitPython project: https://circuitpython.org
;
; SPDX-FileCopyrightText: Copyright (c) 2025 Dan Halbert for Adafruit Industries
;
; SPDX-License-Identifier: MIT

.program i2s
.side_set 2

; Load the next set of samples
; /--- LRCLK
; |/-- BCLK
; ||
pull noblock side 0b11 ; Loads OSR with the next FIFO value or X
mov x osr side 0b11 ; Save the new value in case we need it again
set y 14 side 0b11
bitloop1:
out pins 1 side 0b10 [2] ; Right channel first
jmp y-- bitloop1 side 0b11 [2]
out pins 1 side 0b00 [2]
set y 14 side 0b01 [2]
bitloop0:
out pins 1 side 0b00 [2] ; Then left channel
jmp y-- bitloop0 side 0b01 [2]
out pins 1 side 0b10 [2]
25 changes: 25 additions & 0 deletions ports/raspberrypi/common-hal/audiobusio/i2s_left.pio
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Original file line number Diff line number Diff line change
@@ -0,0 +1,25 @@
; This file is part of the CircuitPython project: https://circuitpython.org
;
; SPDX-FileCopyrightText: Copyright (c) 2025 Dan Halbert for Adafruit Industries
;
; SPDX-License-Identifier: MIT

.program i2s
.side_set 2

; Load the next set of samples
; /--- LRCLK
; |/-- BCLK
; ||
pull noblock side 0b01 ; Loads OSR with the next FIFO value or X
mov x osr side 0b01 ; Save the new value in case we need it again
set y 14 side 0b01
bitloop1:
out pins 1 side 0b10 [2] ; Right channel first
jmp y-- bitloop1 side 0b11 [2]
out pins 1 side 0b10 [2]
set y 14 side 0b11 [2]
bitloop0:
out pins 1 side 0b00 [2] ; Then left channel
jmp y-- bitloop0 side 0b01 [2]
out pins 1 side 0b00 [2]
25 changes: 25 additions & 0 deletions ports/raspberrypi/common-hal/audiobusio/i2s_swap.pio
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,25 @@
; This file is part of the CircuitPython project: https://circuitpython.org
;
; SPDX-FileCopyrightText: Copyright (c) 2025 Dan Halbert for Adafruit Industries
;
; SPDX-License-Identifier: MIT

.program i2s
.side_set 2

; Load the next set of samples
; /--- BCLK
; |/-- LRCLK
; ||
pull noblock side 0b11 ; Loads OSR with the next FIFO value or X
mov x osr side 0b11 ; Save the new value in case we need it again
set y 14 side 0b11
bitloop1:
out pins 1 side 0b01 [2] ; Right channel first
jmp y-- bitloop1 side 0b11 [2]
out pins 1 side 0b00 [2]
set y 14 side 0b10 [2]
bitloop0:
out pins 1 side 0b00 [2] ; Then left channel
jmp y-- bitloop0 side 0b10 [2]
out pins 1 side 0b01 [2]
25 changes: 25 additions & 0 deletions ports/raspberrypi/common-hal/audiobusio/i2s_swap_left.pio
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Original file line number Diff line number Diff line change
@@ -0,0 +1,25 @@
; This file is part of the CircuitPython project: https://circuitpython.org
;
; SPDX-FileCopyrightText: Copyright (c) 2025 Dan Halbert for Adafruit Industries
;
; SPDX-License-Identifier: MIT

.program i2s
.side_set 2

; Load the next set of samples
; /--- BCLK
; |/-- LRCLK
; ||
pull noblock side 0b10 ; Loads OSR with the next FIFO value or X
mov x osr side 0b10 ; Save the new value in case we need it again
set y 14 side 0b10
bitloop1:
out pins 1 side 0b01 [2] ; Right channel first
jmp y-- bitloop1 side 0b11 [2]
out pins 1 side 0b01 [2]
set y 14 side 0b11 [2]
bitloop0:
out pins 1 side 0b00 [2] ; Then left channel
jmp y-- bitloop0 side 0b10 [2]
out pins 1 side 0b00 [2]
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