Update Readme

* Extract keymap definitions to follow the external userspace model. A
  default keymap should probably be added again as an example.
* Move configuration to keyboard.json.
* Enable LTO.
* Move encoder button handling to the keymap for full qmk feature
  support (layers, mod-tap).
* Inject encoder turn events into the qmk encoder pipeline, with the
  same motivation as above.
* Rename files to avoid clashing with qmk-internal files (encoder.h).
* Faster matrix store/compare primitives.

keyboards/cheapino/cheapino.c

@@ -0,0 +1,214 @@
+#include "matrix.h"
+#include "quantum.h"
+#include "print.h"
+
+#include QMK_KEYBOARD_H
+
+// This is to keep state between callbacks, when it is 0 the
+// initial RGB flash is finished
+uint8_t _hue_countdown = 50;
+
+// These are to keep track of user selected color, so we
+// can restore it after RGB flash
+uint8_t _hue;
+uint8_t _saturation;
+uint8_t _value;
+
+// Do a little 2.5 seconds display of the different colors
+// Use the deferred executor so the LED flash dance does not
+// stop us from using the keyboard.
+// https://docs.qmk.fm/#/custom_quantum_functions?id=deferred-executor-registration
+uint32_t flash_led(uint32_t next_trigger_time, void *cb_arg) {
+    rgblight_sethsv(_hue_countdown * 5, 230, 70);
+    _hue_countdown--;
+    if (_hue_countdown == 0) {
+        // Finished, reset to user chosen led color
+        rgblight_sethsv(_hue, _saturation, _value);
+        return 0;
+    } else {
+        return 50;
+    }
+}
+
+void keyboard_post_init_kb(void) {
+    // debug_enable=true;
+    // debug_matrix=true;
+    // debug_keyboard=true;
+    // debug_mouse=true;
+
+    // Store user selected rgb hsv:
+    _hue        = rgblight_get_hue();
+    _saturation = rgblight_get_sat();
+    _value      = rgblight_get_val();
+
+    // Flash a little on start
+    defer_exec(50, flash_led, NULL);
+}
+
+// This is just to be able to declare constants as they appear in the qmk console
+#define rev(b) \
+            ((b & 1) << 15) | \
+            ((b & (1 << 1)) << 13) | \
+            ((b & (1 << 2)) << 11) | \
+            ((b & (1 << 3)) << 9) | \
+            ((b & (1 << 4)) << 7) | \
+            ((b & (1 << 5)) << 5) | \
+            ((b & (1 << 6)) << 3) | \
+            ((b & (1 << 7)) << 1) | \
+            ((b & (1 << 8)) >> 1) | \
+            ((b & (1 << 9)) >> 3) | \
+            ((b & (1 << 10)) >> 5) | \
+            ((b & (1 << 11)) >> 7) | \
+            ((b & (1 << 12)) >> 9) | \
+            ((b & (1 << 13)) >> 11) | \
+            ((b & (1 << 14)) >> 13) | \
+            b >> 15
+
+/* This is for debugging the matrix rows
+void printBits(uint16_t n)
+{
+    long i;
+    for (i = 15; i >= 0; i--) {
+        if ((n & (1 << i)) != 0) {
+            printf("1");
+        }
+        else {
+            printf("0");
+        }
+    }
+    printf("\n");
+}
+*/
+
+bool bit_pattern_set(uint16_t number, uint16_t bitPattern) {
+    return !(~number & bitPattern);
+}
+
+void fix_ghosting_instance(
+        matrix_row_t current_matrix[],
+        unsigned short row_num_with_possible_error_cause,
+        uint16_t possible_error_cause,
+        unsigned short row_num_with_possible_error,
+        uint16_t possible_error,
+        uint16_t error_fix) {
+    if (bit_pattern_set(current_matrix[row_num_with_possible_error_cause], possible_error_cause)) {
+        if (bit_pattern_set(current_matrix[row_num_with_possible_error], possible_error)) {
+            current_matrix[row_num_with_possible_error] = current_matrix[row_num_with_possible_error] ^ error_fix;
+        }
+    }
+}
+
+void fix_ghosting_column(
+        matrix_row_t matrix[],
+        uint16_t possible_error_cause,
+        uint16_t possible_error,
+        uint16_t error_fix) {
+    // First the right side
+    for (short i = 0; i<3; i++) {
+        fix_ghosting_instance(matrix, i, possible_error_cause, (i+1)%3, possible_error, error_fix);
+        fix_ghosting_instance(matrix, i, possible_error_cause, (i+2)%3, possible_error, error_fix);
+    }
+
+    // Then exactly same procedure on the left side
+    for (short i = 0; i<3; i++) {
+        fix_ghosting_instance(matrix, i+4, possible_error_cause<<6, 4+((i+1)%3), possible_error<<6, error_fix<<6);
+        fix_ghosting_instance(matrix, i+4, possible_error_cause<<6, 4+((i+2)%3), possible_error<<6, error_fix<<6);
+    }
+}
+
+// For QWERTY layout, key combo a+s+e also outputs q. This suppresses the q, and other similar ghosts
+// These are observed ghosts(following a pattern). TODO: need to fix this for v3
+// Might need to add 2 diodes(one in each direction) for every row, to increase voltage drop.
+void fix_ghosting(matrix_row_t matrix[]) {
+    fix_ghosting_column(matrix,
+                        rev(0B0110000000000000),
+                        rev(0B1010000000000000),
+                        rev(0B0010000000000000));
+    fix_ghosting_column(matrix,
+                        rev(0B0110000000000000),
+                        rev(0B0101000000000000),
+                        rev(0B0100000000000000));
+
+    fix_ghosting_column(matrix,
+                        rev(0B0001100000000000),
+                        rev(0B0010100000000000),
+                        rev(0B0000100000000000));
+    fix_ghosting_column(matrix,
+                        rev(0B0001100000000000),
+                        rev(0B0001010000000000),
+                        rev(0B0001000000000000));
+
+    fix_ghosting_column(matrix,
+                        rev(0B1000010000000000),
+                        rev(0B1000100000000000),
+                        rev(0B1000000000000000));
+    fix_ghosting_column(matrix,
+                        rev(0B1000010000000000),
+                        rev(0B0100010000000000),
+                        rev(0B0000010000000000));
+
+    fix_ghosting_column(matrix,
+                        rev(0B1001000000000000),
+                        rev(0B0101000000000000),
+                        rev(0B0001000000000000));
+    fix_ghosting_column(matrix,
+                        rev(0B1001000000000000),
+                        rev(0B1010000000000000),
+                        rev(0B1000000000000000));
+
+    fix_ghosting_column(matrix,
+                        rev(0B0100100000000000),
+                        rev(0B0100010000000000),
+                        rev(0B0100000000000000));
+    fix_ghosting_column(matrix,
+                        rev(0B0100100000000000),
+                        rev(0B1000100000000000),
+                        rev(0B0000100000000000));
+}
+
+void encoder_driver_task(void) {
+    // This is intentionally left empty to disable the default encoder driver.
+    // We inject events manually below.
+}
+
+// There aren't enough pins on the RJ45 for dedicated encoder pins. Use matrix
+// intersections instead.
+void fix_encoder_action(matrix_row_t current_matrix[]) {
+    static const int ENC_ROW   = 3;
+    static const int ENC_A_COL = 2;
+    static const int ENC_B_COL = 4;
+    // The button column is unused here and handled through the keymap instead.
+    // static const int ENC_BUTTON_COL = 0;
+    static const matrix_row_t ENC_A_BIT = (1 << ENC_A_COL);
+    static const matrix_row_t ENC_B_BIT = (1 << ENC_B_COL);
+
+    // State machine tracking.
+    static bool colABPressed = false;
+
+    // Check which way the encoder is turned:
+    matrix_row_t encoder_row = current_matrix[ENC_ROW];
+    bool         colA        = encoder_row & ENC_A_BIT;
+    bool         colB        = encoder_row & ENC_B_BIT;
+
+    extern bool encoder_queue_event(uint8_t, bool);
+    if (colA && colB) {
+        colABPressed = true;
+    } else if (colA) {
+        if (colABPressed) {
+            // A+B followed by A means clockwise
+            colABPressed = false;
+            encoder_queue_event(0, true);
+        }
+    } else if (colB) {
+        if (colABPressed) {
+            // A+B followed by B means counter-clockwise
+            colABPressed = false;
+            encoder_queue_event(0, false);
+        }
+    }
+
+    // Clear A+B bits, and leave the button bits intact; it will be picked up
+    // by normal matrix/keymap processing.
+    static const matrix_row_t ROW_MASK = ~(ENC_A_BIT | ENC_B_BIT);
+    current_matrix[ENC_ROW]            = encoder_row & ROW_MASK;
+}

keyboards/cheapino/config.h

@@ -0,0 +1,8 @@
+// Copyright 2023 Thomas Haukland (@tompi)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+// Force the usage of PIO1 peripheral, by default the WS2812 implementation uses the PIO0 peripheral.
+#define WS2812_PIO_USE_PIO1
+#define WS2812_BYTE_ORDER WS2812_BYTE_ORDER_RGB

keyboards/cheapino/keyboard.json

@@ -0,0 +1,137 @@
+{
+    "manufacturer": "Thomas Haukland",
+    "keyboard_name": "cheapino2",
+    "maintainer": "tompi",
+    "bootloader": "rp2040",
+    "diode_direction": "ROW2COL",
+    "ws2812": {
+        "driver": "vendor",
+        "pin": "GP16"
+    },
+    "features": {
+        "bootmagic": true,
+        "caps_word": true,
+        "command": false,
+        "console": false,
+        "deferred_exec": true,
+        "encoder": true,
+        "extrakey": true,
+        "mousekey": true,
+        "nkro": false,
+        "rgblight": true
+    },
+    "tapping": {
+        "term": 230
+    },
+    "caps_word": {
+        "both_shifts_turns_on": true
+    },
+    "encoder": {
+        "_comment0": "These are unused but have to be defined. The encoder is",
+        "_comment1": "actually handled by matrix intersections; see encoder.c",
+        "rotary": [
+            {
+                "pin_a": "GP9",
+                "pin_b": "GP10"
+            }
+        ]
+    },
+    "rgblight": {
+        "led_count": 1,
+        "default": {
+            "hue": 128,
+            "sat": 128,
+            "val": 64
+        }
+    },
+    "matrix_pins": {
+        "custom": true,
+        "custom_lite": true,
+        "cols": [
+            "GP6",
+            "GP6",
+            "GP5",
+            "GP5",
+            "GP4",
+            "GP4",
+
+            "GP14",
+            "GP14",
+            "GP15",
+            "GP15",
+            "GP26",
+            "GP26"
+        ],
+        "rows": [
+            "GP3",
+            "GP1",
+            "GP2",
+            "GP0",
+            "GP27",
+            "GP28",
+            "GP29",
+            "GP8"
+        ]
+    },
+    "processor": "RP2040",
+    "url": "",
+    "usb": {
+        "device_version": "1.0.0",
+        "pid": "0x0000",
+        "vid": "0xFEE3"
+    },
+    "layouts": {
+        "LAYOUT_split_3x5_3": {
+            "layout": [
+                { "matrix": [4, 10], "x": 0, "y": 0.25 },
+                { "matrix": [4, 9], "x": 1, "y": 0.125 },
+                { "matrix": [4, 8], "x": 2, "y": 0 },
+                { "matrix": [4, 7], "x": 3, "y": 0.125 },
+                { "matrix": [4, 6], "x": 4, "y": 0.25 },
+
+                { "matrix": [3, 0], "x": 6, "y": 0.25 },
+
+                { "matrix": [0, 0], "x": 7, "y": 0.25 },
+                { "matrix": [0, 1], "x": 8, "y": 0.125 },
+                { "matrix": [0, 2], "x": 9, "y": 0 },
+                { "matrix": [0, 3], "x": 10, "y": 0.125 },
+                { "matrix": [0, 4], "x": 11, "y": 0.25 },
+
+
+                { "matrix": [5, 10], "x": 0, "y": 1.25 },
+                { "matrix": [5, 9], "x": 1, "y": 1.125 },
+                { "matrix": [5, 8], "x": 2, "y": 1 },
+                { "matrix": [5, 7], "x": 3, "y": 1.125 },
+                { "matrix": [5, 6], "x": 4, "y": 1.25 },
+
+                { "matrix": [1, 0], "x": 7, "y": 1.25 },
+                { "matrix": [1, 1], "x": 8, "y": 1.125 },
+                { "matrix": [1, 2], "x": 9, "y": 1 },
+                { "matrix": [1, 3], "x": 10, "y": 1.125 },
+                { "matrix": [1, 4], "x": 11, "y": 1.25 },
+
+
+                { "matrix": [6, 10], "x": 0, "y": 2.25 },
+                { "matrix": [6, 9], "x": 1, "y": 2.125 },
+                { "matrix": [6, 8], "x": 2, "y": 2 },
+                { "matrix": [6, 7], "x": 3, "y": 2.125 },
+                { "matrix": [6, 6], "x": 4, "y": 2.25 },
+
+                { "matrix": [2, 0], "x": 7, "y": 2.25 },
+                { "matrix": [2, 1], "x": 8, "y": 2.125 },
+                { "matrix": [2, 2], "x": 9, "y": 2 },
+                { "matrix": [2, 3], "x": 10, "y": 2.125 },
+                { "matrix": [2, 4], "x": 11, "y": 2.25 },
+
+
+                { "matrix": [6, 11], "x": 2.5, "y": 3.25 },
+                { "matrix": [5, 11], "x": 3.5, "y": 3.5 },
+                { "matrix": [4, 11], "x": 4.5, "y": 3.75 },
+
+                { "matrix": [0, 5], "x": 6.5, "y": 3.75 },
+                { "matrix": [1, 5], "x": 7.5, "y": 3.5 },
+                { "matrix": [2, 5], "x": 8.5, "y": 3.25 }
+            ]
+        }
+    }
+}

keyboards/cheapino/matrix.c

@@ -0,0 +1,148 @@
+/*
+Copyright 2012 Jun Wako <wakojun@gmail.com>
+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
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+ Copied from here: https://github.com/e3w2q/qmk_firmware/blob/762fe3e0a7cbea768245a75520f06ff5a2f00b9f/keyboards/2x3test/matrix.c
+*/
+
+/*
+ * scan matrix
+ */
+#include <stdint.h>
+#include <stdbool.h>
+#include "wait.h"
+#include "util.h"
+#include "matrix.h"
+#include "config.h"
+#include "quantum.h"
+#include "debounce.h"
+#include "print.h"
+
+// How long the scanning code waits for changed io to settle.
+// Adjust from default 30 to weigh up for increased time spent ghost-hunting.
+// (the rp2040 does not seem to have any problems with this value...)
+#define MATRIX_IO_DELAY 25
+
+#define COL_SHIFTER ((uint16_t)1)
+
+static const pin_t row_pins[] = MATRIX_ROW_PINS;
+static const pin_t col_pins[] = MATRIX_COL_PINS;
+static matrix_row_t previous_matrix[MATRIX_ROWS];
+
+static void select_row(uint8_t row) {
+    setPinOutput(row_pins[row]);
+    writePinLow(row_pins[row]);
+}
+
+static void unselect_row(uint8_t row) { setPinInputHigh(row_pins[row]); }
+
+static void unselect_rows(void) {
+    for (uint8_t x = 0; x < MATRIX_ROWS; x++) {
+        setPinInputHigh(row_pins[x]);
+    }
+}
+
+static void select_col(uint8_t col) {
+    setPinOutput(col_pins[col]);
+    writePinLow(col_pins[col]);
+}
+
+static void unselect_col(uint8_t col) {
+    setPinInputHigh(col_pins[col]);
+}
+
+static void unselect_cols(void) {
+    for (uint8_t x = 0; x < MATRIX_COLS/2; x++) {
+        setPinInputHigh(col_pins[x*2]);
+    }
+}
+
+static void read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row) {
+    // Select row and wait for row selection to stabilize
+    select_row(current_row);
+    wait_us(MATRIX_IO_DELAY);
+
+    // For each col...
+    for (uint8_t col_index = 0; col_index < MATRIX_COLS / 2; col_index++) {
+        uint16_t column_index_bitmask = COL_SHIFTER << ((col_index * 2) + 1);
+        // Check row pin state
+        if (readPin(col_pins[col_index*2])) {
+            // Pin HI, clear col bit
+            current_matrix[current_row] &= ~column_index_bitmask;
+        } else {
+            // Pin LO, set col bit
+            current_matrix[current_row] |= column_index_bitmask;
+        }
+    }
+
+    // Unselect row
+    unselect_row(current_row);
+}
+
+static void read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col) {
+    // Select col and wait for col selection to stabilize
+    select_col(current_col*2);
+    wait_us(MATRIX_IO_DELAY);
+
+    uint16_t column_index_bitmask = COL_SHIFTER << (current_col * 2);
+    // For each row...
+    for (uint8_t row_index = 0; row_index < MATRIX_ROWS; row_index++) {
+        // Check row pin state
+        if (readPin(row_pins[row_index])) {
+            // Pin HI, clear col bit
+            current_matrix[row_index] &= ~column_index_bitmask;
+        } else {
+            // Pin LO, set col bit
+            current_matrix[row_index] |= column_index_bitmask;
+        }
+    }
+    // Unselect col
+    unselect_col(current_col*2);
+}
+
+
+void matrix_init_custom(void) {
+    // initialize key pins
+    unselect_cols();
+    unselect_rows();
+    debounce_init();
+}
+
+void store_old_matrix(matrix_row_t current_matrix[]) {
+    memcpy(previous_matrix, current_matrix, MATRIX_ROWS * sizeof(matrix_row_t));
+}
+
+bool has_matrix_changed(matrix_row_t current_matrix[]) {
+    return memcmp(previous_matrix, current_matrix, MATRIX_ROWS * sizeof(matrix_row_t)) != 0;
+}
+
+bool matrix_scan_custom(matrix_row_t current_matrix[]) {
+    extern void fix_encoder_action(matrix_row_t current_matrix[]);
+    extern void fix_ghosting(matrix_row_t matrix[]);
+
+    store_old_matrix(current_matrix);
+    // Set row, read cols
+    for (uint8_t current_row = 0; current_row < MATRIX_ROWS; current_row++) {
+        read_cols_on_row(current_matrix, current_row);
+    }
+    // Set col, read rows
+    for (uint8_t current_col = 0; current_col < MATRIX_COLS/2; current_col++) {
+        read_rows_on_col(current_matrix, current_col);
+    }
+
+    fix_encoder_action(current_matrix);
+
+    fix_ghosting(current_matrix);
+
+    return has_matrix_changed(current_matrix);
+}
+

keyboards/cheapino/mcuconf.h

@@ -0,0 +1,6 @@
+ #pragma once
+
+#include_next <mcuconf.h>
+
+#undef RP_I2C_USE_I2C1
+#define RP_I2C_USE_I2C1 TRUE

keyboards/cheapino/readme.md

@@ -0,0 +1,27 @@
+# cheapino
+
+![cheapino](https://raw.githubusercontent.com/tompi/cheapino/refs/heads/master/doc/gallery/27.png)
+
+*A short description of the keyboard/project*
+
+* Keyboard Maintainer: [Thomas Haukland](https://github.com/tompi)
+* Hardware Supported: pcb v2 with RP2040-Zero MCU
+* Hardware Availability: https://github.com/tompi/cheapino
+
+Make example for this keyboard (after setting up your build environment):
+
+    make cheapino:default
+
+Flashing example for this keyboard:
+
+    make cheapino:default:flash
+
+See the [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) and the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information. Brand new to QMK? Start with our [Complete Newbs Guide](https://docs.qmk.fm/#/newbs).
+
+## Bootloader
+
+Enter the bootloader in 3 ways:
+
+* **Bootmagic reset**: Hold down the key at (0,0) in the matrix (usually the top left key or Escape) and plug in the keyboard
+* **Physical reset button**: Briefly press the button on the back of the PCB - some may have pads you must short instead
+* **Keycode in layout**: Press the key mapped to `QK_BOOT` if it is available

keyboards/cheapino/rules.mk

@@ -0,0 +1 @@
+SRC += matrix.c