From b829a1d2648abd0751e9d3505554547faf643425 Mon Sep 17 00:00:00 2001 From: Simon Arlott <70171+nomis@users.noreply.github.com> Date: Wed, 9 Jun 2021 08:23:21 +0100 Subject: Avoid 8-bit timer overflows in debounce algorithms (#12240) * Add fast_timer_t that is 16-bit or 32-bit based on architecture A 16-bit timer will overflow sooner but be faster to compare on AVR. * Avoid 8-bit timer overflows in debounce algorithms Count down remaining elapsed time instead of trying to do 8-bit timer comparisons. Add a "none" implementation that is automatically used if DEBOUNCE is 0 otherwise it will break the _pk/_pr count down. * Avoid unnecessary polling of the entire matrix in sym_eager_pk The matrix only needs to be updated when a debounce timer expires. * Avoid unnecessary polling of the entire matrix in sym_eager_pr The matrix only needs to be updated when a debounce timer expires. The use of the "needed_update" variable is trying to do what "matrix_need_update" was added to fix but didn't work because it only applied when all keys finished debouncing. * Fix sym_defer_g timing inconsistency compared to other debounce algorithms DEBOUNCE=5 should process the key after 5ms, not 6ms * Add debounce tests --- quantum/debounce/sym_defer_pk.c | 67 +++++++++++++++++++++++++++-------------- 1 file changed, 45 insertions(+), 22 deletions(-) (limited to 'quantum/debounce/sym_defer_pk.c') diff --git a/quantum/debounce/sym_defer_pk.c b/quantum/debounce/sym_defer_pk.c index 60513f98e1..626a9be841 100644 --- a/quantum/debounce/sym_defer_pk.c +++ b/quantum/debounce/sym_defer_pk.c @@ -1,6 +1,7 @@ /* Copyright 2017 Alex Ong Copyright 2020 Andrei Purdea +Copyright 2021 Simon Arlott This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or @@ -33,28 +34,25 @@ When no state changes have occured for DEBOUNCE milliseconds, we push the state. # define DEBOUNCE 5 #endif +// Maximum debounce: 255ms +#if DEBOUNCE > UINT8_MAX +# undef DEBOUNCE +# define DEBOUNCE UINT8_MAX +#endif + #define ROW_SHIFTER ((matrix_row_t)1) -#define debounce_counter_t uint8_t +typedef uint8_t debounce_counter_t; +#if DEBOUNCE > 0 static debounce_counter_t *debounce_counters; +static fast_timer_t last_time; static bool counters_need_update; -#define DEBOUNCE_ELAPSED 251 -#define MAX_DEBOUNCE (DEBOUNCE_ELAPSED - 1) - -static uint8_t wrapping_timer_read(void) { - static uint16_t time = 0; - static uint8_t last_result = 0; - uint16_t new_time = timer_read(); - uint16_t diff = new_time - time; - time = new_time; - last_result = (last_result + diff) % (MAX_DEBOUNCE + 1); - return last_result; -} +#define DEBOUNCE_ELAPSED 0 -void update_debounce_counters_and_transfer_if_expired(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t current_time); -void start_debounce_counters(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t current_time); +static void update_debounce_counters_and_transfer_if_expired(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t elapsed_time); +static void start_debounce_counters(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows); // we use num_rows rather than MATRIX_ROWS to support split keyboards void debounce_init(uint8_t num_rows) { @@ -67,27 +65,49 @@ void debounce_init(uint8_t num_rows) { } } +void debounce_free(void) { + free(debounce_counters); + debounce_counters = NULL; +} + void debounce(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, bool changed) { - uint8_t current_time = wrapping_timer_read(); + bool updated_last = false; + if (counters_need_update) { - update_debounce_counters_and_transfer_if_expired(raw, cooked, num_rows, current_time); + fast_timer_t now = timer_read_fast(); + fast_timer_t elapsed_time = TIMER_DIFF_FAST(now, last_time); + + last_time = now; + updated_last = true; + if (elapsed_time > UINT8_MAX) { + elapsed_time = UINT8_MAX; + } + + if (elapsed_time > 0) { + update_debounce_counters_and_transfer_if_expired(raw, cooked, num_rows, elapsed_time); + } } if (changed) { - start_debounce_counters(raw, cooked, num_rows, current_time); + if (!updated_last) { + last_time = timer_read_fast(); + } + + start_debounce_counters(raw, cooked, num_rows); } } -void update_debounce_counters_and_transfer_if_expired(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t current_time) { +static void update_debounce_counters_and_transfer_if_expired(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t elapsed_time) { counters_need_update = false; debounce_counter_t *debounce_pointer = debounce_counters; for (uint8_t row = 0; row < num_rows; row++) { for (uint8_t col = 0; col < MATRIX_COLS; col++) { if (*debounce_pointer != DEBOUNCE_ELAPSED) { - if (TIMER_DIFF(current_time, *debounce_pointer, MAX_DEBOUNCE) >= DEBOUNCE) { + if (*debounce_pointer <= elapsed_time) { *debounce_pointer = DEBOUNCE_ELAPSED; cooked[row] = (cooked[row] & ~(ROW_SHIFTER << col)) | (raw[row] & (ROW_SHIFTER << col)); } else { + *debounce_pointer -= elapsed_time; counters_need_update = true; } } @@ -96,14 +116,14 @@ void update_debounce_counters_and_transfer_if_expired(matrix_row_t raw[], matrix } } -void start_debounce_counters(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t current_time) { +static void start_debounce_counters(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows) { debounce_counter_t *debounce_pointer = debounce_counters; for (uint8_t row = 0; row < num_rows; row++) { matrix_row_t delta = raw[row] ^ cooked[row]; for (uint8_t col = 0; col < MATRIX_COLS; col++) { if (delta & (ROW_SHIFTER << col)) { if (*debounce_pointer == DEBOUNCE_ELAPSED) { - *debounce_pointer = current_time; + *debounce_pointer = DEBOUNCE; counters_need_update = true; } } else { @@ -115,3 +135,6 @@ void start_debounce_counters(matrix_row_t raw[], matrix_row_t cooked[], uint8_t } bool debounce_active(void) { return true; } +#else +# include "none.c" +#endif -- cgit v1.2.3