Add encoder abstraction. (#21548)

1 files changed, 213 insertions, 0 deletions

diff --git a/drivers/encoder/encoder_quadrature.c b/drivers/encoder/encoder_quadrature.c
new file mode 100644
index 0000000000..cd589bf1e2
--- /dev/null
+++ b/drivers/encoder/encoder_quadrature.c
@@ -0,0 +1,213 @@
+// Copyright 2018 Jack Humbert <jack.humb@gmail.com>
+// Copyright 2018-2023 Nick Brassel (@tzarc)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <stdint.h>
+#include "encoder.h"
+#include "gpio.h"
+#include "keyboard.h"
+#include "action.h"
+#include "keycodes.h"
+#include "wait.h"
+
+#ifdef SPLIT_KEYBOARD
+#    include "split_util.h"
+#endif
+
+// for memcpy
+#include <string.h>
+
+#if !defined(ENCODER_RESOLUTIONS) && !defined(ENCODER_RESOLUTION)
+#    define ENCODER_RESOLUTION 4
+#endif
+
+#undef ENCODER_DEFAULT_PIN_API_IMPL
+#if defined(ENCODERS_PAD_A) && defined(ENCODERS_PAD_B)
+// Inform the quadrature driver that it needs to implement pin init/read functions
+#    define ENCODER_DEFAULT_PIN_API_IMPL
+#endif
+
+extern volatile bool isLeftHand;
+
+__attribute__((weak)) void    encoder_quadrature_init_pin(uint8_t index, bool pad_b);
+__attribute__((weak)) uint8_t encoder_quadrature_read_pin(uint8_t index, bool pad_b);
+
+#ifdef ENCODER_DEFAULT_PIN_API_IMPL
+
+static pin_t encoders_pad_a[NUM_ENCODERS_MAX_PER_SIDE] = ENCODERS_PAD_A;
+static pin_t encoders_pad_b[NUM_ENCODERS_MAX_PER_SIDE] = ENCODERS_PAD_B;
+
+__attribute__((weak)) void encoder_wait_pullup_charge(void) {
+    wait_us(100);
+}
+
+__attribute__((weak)) void encoder_quadrature_init_pin(uint8_t index, bool pad_b) {
+    pin_t pin = pad_b ? encoders_pad_b[index] : encoders_pad_a[index];
+    if (pin != NO_PIN) {
+        gpio_set_pin_input_high(pin);
+    }
+}
+
+__attribute__((weak)) uint8_t encoder_quadrature_read_pin(uint8_t index, bool pad_b) {
+    pin_t pin = pad_b ? encoders_pad_b[index] : encoders_pad_a[index];
+    if (pin != NO_PIN) {
+        return gpio_read_pin(pin) ? 1 : 0;
+    }
+    return 0;
+}
+
+#endif // ENCODER_DEFAULT_PIN_API_IMPL
+
+#ifdef ENCODER_RESOLUTIONS
+static uint8_t encoder_resolutions[NUM_ENCODERS] = ENCODER_RESOLUTIONS;
+#endif
+
+#ifndef ENCODER_DIRECTION_FLIP
+#    define ENCODER_CLOCKWISE true
+#    define ENCODER_COUNTER_CLOCKWISE false
+#else
+#    define ENCODER_CLOCKWISE false
+#    define ENCODER_COUNTER_CLOCKWISE true
+#endif
+static int8_t encoder_LUT[] = {0, -1, 1, 0, 1, 0, 0, -1, -1, 0, 0, 1, 0, 1, -1, 0};
+
+static uint8_t encoder_state[NUM_ENCODERS]  = {0};
+static int8_t  encoder_pulses[NUM_ENCODERS] = {0};
+
+// encoder counts
+static uint8_t thisCount;
+#ifdef SPLIT_KEYBOARD
+// encoder offsets for each hand
+static uint8_t thisHand, thatHand;
+// encoder counts for each hand
+static uint8_t thatCount;
+#endif
+
+__attribute__((weak)) void encoder_quadrature_post_init_kb(void) {
+    extern void encoder_quadrature_handle_read(uint8_t index, uint8_t pin_a_state, uint8_t pin_b_state);
+    // Unused normally, but can be used for things like setting up pin-change interrupts in keyboard code.
+    // During the interrupt, read the pins then call `encoder_handle_read()` with the pin states and it'll queue up an encoder event if needed.
+}
+
+void encoder_quadrature_post_init(void) {
+#ifdef ENCODER_DEFAULT_PIN_API_IMPL
+    for (uint8_t i = 0; i < thisCount; i++) {
+        encoder_quadrature_init_pin(i, false);
+        encoder_quadrature_init_pin(i, true);
+    }
+    encoder_wait_pullup_charge();
+    for (uint8_t i = 0; i < thisCount; i++) {
+        encoder_state[i] = (encoder_quadrature_read_pin(i, false) << 0) | (encoder_quadrature_read_pin(i, true) << 1);
+    }
+#else
+    memset(encoder_state, 0, sizeof(encoder_state));
+#endif
+
+    encoder_quadrature_post_init_kb();
+}
+
+void encoder_driver_init(void) {
+#ifdef SPLIT_KEYBOARD
+    thisHand  = isLeftHand ? 0 : NUM_ENCODERS_LEFT;
+    thatHand  = NUM_ENCODERS_LEFT - thisHand;
+    thisCount = isLeftHand ? NUM_ENCODERS_LEFT : NUM_ENCODERS_RIGHT;
+    thatCount = isLeftHand ? NUM_ENCODERS_RIGHT : NUM_ENCODERS_LEFT;
+#else // SPLIT_KEYBOARD
+    thisCount                = NUM_ENCODERS;
+#endif
+
+#ifdef ENCODER_TESTS
+    // Annoying that we have to clear out values during initialisation here, but
+    // because all the arrays are static locals, rerunning tests in the same
+    // executable doesn't reset any of these. Kinda crappy having test-only code
+    // here, but it's the simplest solution.
+    memset(encoder_state, 0, sizeof(encoder_state));
+    memset(encoder_pulses, 0, sizeof(encoder_pulses));
+    const pin_t encoders_pad_a_left[] = ENCODERS_PAD_A;
+    const pin_t encoders_pad_b_left[] = ENCODERS_PAD_B;
+    for (uint8_t i = 0; i < thisCount; i++) {
+        encoders_pad_a[i] = encoders_pad_a_left[i];
+        encoders_pad_b[i] = encoders_pad_b_left[i];
+    }
+#endif
+
+#if defined(SPLIT_KEYBOARD) && defined(ENCODERS_PAD_A_RIGHT) && defined(ENCODERS_PAD_B_RIGHT)
+    // Re-initialise the pads if it's the right-hand side
+    if (!isLeftHand) {
+        const pin_t encoders_pad_a_right[] = ENCODERS_PAD_A_RIGHT;
+        const pin_t encoders_pad_b_right[] = ENCODERS_PAD_B_RIGHT;
+        for (uint8_t i = 0; i < thisCount; i++) {
+            encoders_pad_a[i] = encoders_pad_a_right[i];
+            encoders_pad_b[i] = encoders_pad_b_right[i];
+        }
+    }
+#endif // defined(SPLIT_KEYBOARD) && defined(ENCODERS_PAD_A_RIGHT) && defined(ENCODERS_PAD_B_RIGHT)
+
+    // Encoder resolutions is defined differently in config.h, so concatenate
+#if defined(SPLIT_KEYBOARD) && defined(ENCODER_RESOLUTIONS)
+#    if defined(ENCODER_RESOLUTIONS_RIGHT)
+    static const uint8_t encoder_resolutions_right[NUM_ENCODERS_RIGHT] = ENCODER_RESOLUTIONS_RIGHT;
+#    else  // defined(ENCODER_RESOLUTIONS_RIGHT)
+    static const uint8_t encoder_resolutions_right[NUM_ENCODERS_RIGHT] = ENCODER_RESOLUTIONS;
+#    endif // defined(ENCODER_RESOLUTIONS_RIGHT)
+    for (uint8_t i = 0; i < NUM_ENCODERS_RIGHT; i++) {
+        encoder_resolutions[NUM_ENCODERS_LEFT + i] = encoder_resolutions_right[i];
+    }
+#endif // defined(SPLIT_KEYBOARD) && defined(ENCODER_RESOLUTIONS)
+
+    encoder_quadrature_post_init();
+}
+
+static void encoder_handle_state_change(uint8_t index, uint8_t state) {
+    uint8_t i = index;
+
+#ifdef SPLIT_KEYBOARD
+    index += thisHand;
+#endif
+
+#ifdef ENCODER_RESOLUTIONS
+    const uint8_t resolution = encoder_resolutions[index];
+#else
+    const uint8_t resolution = ENCODER_RESOLUTION;
+#endif
+
+    encoder_pulses[i] += encoder_LUT[state & 0xF];
+
+#ifdef ENCODER_DEFAULT_POS
+    if ((encoder_pulses[i] >= resolution) || (encoder_pulses[i] <= -resolution) || ((state & 0x3) == ENCODER_DEFAULT_POS)) {
+        if (encoder_pulses[i] >= 1) {
+#else
+    if (encoder_pulses[i] >= resolution) {
+#endif
+
+            encoder_queue_event(index, ENCODER_COUNTER_CLOCKWISE);
+        }
+
+#ifdef ENCODER_DEFAULT_POS
+        if (encoder_pulses[i] <= -1) {
+#else
+    if (encoder_pulses[i] <= -resolution) { // direction is arbitrary here, but this clockwise
+#endif
+            encoder_queue_event(index, ENCODER_CLOCKWISE);
+        }
+        encoder_pulses[i] %= resolution;
+#ifdef ENCODER_DEFAULT_POS
+        encoder_pulses[i] = 0;
+    }
+#endif
+}
+
+void encoder_quadrature_handle_read(uint8_t index, uint8_t pin_a_state, uint8_t pin_b_state) {
+    uint8_t state = pin_a_state | (pin_b_state << 1);
+    if ((encoder_state[index] & 0x3) != state) {
+        encoder_state[index] <<= 2;
+        encoder_state[index] |= state;
+        encoder_handle_state_change(index, encoder_state[index]);
+    }
+}
+
+__attribute__((weak)) void encoder_driver_task(void) {
+    for (uint8_t i = 0; i < thisCount; i++) {
+        encoder_quadrature_handle_read(i, encoder_quadrature_read_pin(i, false), encoder_quadrature_read_pin(i, true));
+    }
+}