qmk_firmware/keyboards/handwired/onekey/keymaps/backlight/keymap.c

#include QMK_KEYBOARD_H

//Tap Dance Declarations
enum {
    TD_BL = 0
};

void dance_cln_finished(qk_tap_dance_state_t *state, void *user_data) {
    // noop
}

void dance_cln_reset(qk_tap_dance_state_t *state, void *user_data) {
    switch (state->count) {
        case 1:
            // single tap - step through backlight
            backlight_step();
            break;
#ifdef BACKLIGHT_BREATHING
        case 2:
            // double tap - toggle breathing
            breathing_toggle();
            break;
        case 3:
            // triple tap - do some pulse stuff
            breathing_pulse();
            break;
#endif
        default:
            break;
    }
}

qk_tap_dance_action_t tap_dance_actions[] = {
    [TD_BL]  = ACTION_TAP_DANCE_FN_ADVANCED(NULL, dance_cln_finished, dance_cln_reset)
};

const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
    LAYOUT_ortho_1x1(TD(TD_BL))
};