Add Keychron C2 Pro (#20701)

Co-authored-by: Drashna Jaelre <drashna@live.com>
Co-authored-by: adophoxia <100170946+adophoxia@users.noreply.github.com>
Co-authored-by: jack <0x6a73@protonmail.com>

keyboards/keychron/c2_pro/matrix.c

@@ -0,0 +1,202 @@
+/* Copyright 2023 @ Keychron (https://www.keychron.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/>.
+ */
+
+#include "quantum.h"
+
+#ifndef SHIFT_COL_START
+#    define SHIFT_COL_START 8
+#endif
+#ifndef SHIFT_COL_END
+#    define SHIFT_COL_END 15
+#endif
+
+#if defined(SHIFT_COL_START) && defined(SHIFT_COL_END)
+#    if ((SHIFT_COL_END - SHIFT_COL_START) > 16)
+#        define SIZE_T uint32_t
+#        define UNSELECT_ALL_COL 0xFFFFFFFF
+#    elif ((SHIFT_COL_END - SHIFT_COL_START) > 8)
+#        define SIZE_T uint16_t
+#        define UNSELECT_ALL_COL 0xFFFF
+#    else
+#        define SIZE_T uint8_t
+#        define UNSELECT_ALL_COL 0xFF
+#    endif
+#endif
+
+pin_t row_pins[MATRIX_ROWS] = MATRIX_ROW_PINS;
+pin_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
+
+static inline void setPinOutput_writeLow(pin_t pin) {
+    ATOMIC_BLOCK_FORCEON {
+        setPinOutput(pin);
+        writePinLow(pin);
+    }
+}
+
+static inline void setPinOutput_writeHigh(pin_t pin) {
+    ATOMIC_BLOCK_FORCEON {
+        setPinOutput(pin);
+        writePinHigh(pin);
+    }
+}
+
+static inline void setPinInput_high(pin_t pin) {
+    ATOMIC_BLOCK_FORCEON {
+        setPinInputHigh(pin);
+    }
+}
+
+static inline uint8_t readMatrixPin(pin_t pin) {
+    if (pin != NO_PIN) {
+        return readPin(pin);
+    } else {
+        return 1;
+    }
+}
+
+static inline void HC595_delay(uint8_t n) {
+    while (n-- > 0) {
+        asm volatile("nop" ::: "memory");
+    }
+}
+
+static void HC595_output(SIZE_T data, uint8_t bit) {
+    uint8_t n = 1;
+
+    ATOMIC_BLOCK_FORCEON {
+        for (uint8_t i = 0; i < (SHIFT_COL_END - SHIFT_COL_START + 1); i++) {
+            if (data & 0x1) {
+                writePinHigh(HC595_DS);
+            } else {
+                writePinLow(HC595_DS);
+            }
+            writePinHigh(HC595_SHCP);
+            HC595_delay(n);
+            writePinLow(HC595_SHCP);
+            HC595_delay(n);
+            if (bit) {
+                break;
+            } else {
+                data = data >> 1;
+            }
+        }
+        writePinHigh(HC595_STCP);
+        HC595_delay(n);
+        writePinLow(HC595_STCP);
+        HC595_delay(n);
+    }
+}
+
+static bool select_col(uint8_t col) {
+    pin_t pin = col_pins[col];
+
+    if (col < SHIFT_COL_START || col > SHIFT_COL_END) {
+        setPinOutput_writeLow(pin);
+        return true;
+    } else {
+        if (col == SHIFT_COL_START) {
+            HC595_output(0x00, 1);
+        }
+        return true;
+    }
+    return false;
+}
+
+static void unselect_col(uint8_t col) {
+    pin_t pin = col_pins[col];
+
+    if (col < SHIFT_COL_START || col > SHIFT_COL_END) {
+#ifdef MATRIX_UNSELECT_DRIVE_HIGH
+        setPinOutput_writeHigh(pin);
+#else
+        setPinInput_high(pin);
+#endif
+    } else {
+        HC595_output(0x01, 1);
+    }
+}
+
+static void unselect_cols(void) {
+    for (uint8_t x = 0; x < MATRIX_COLS; x++) {
+        pin_t pin = col_pins[x];
+        if (x < SHIFT_COL_START || x > SHIFT_COL_END) {
+#ifdef MATRIX_UNSELECT_DRIVE_HIGH
+            setPinOutput_writeHigh(pin);
+#else
+            setPinInput_high(pin);
+#endif
+        } else {
+            if (x == SHIFT_COL_START) HC595_output(UNSELECT_ALL_COL, 0);
+        }
+    }
+}
+
+static void matrix_read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col, matrix_row_t row_shifter) {
+    bool key_pressed = false;
+
+    // Select col
+    if (!select_col(current_col)) { // select col
+        return;                     // skip NO_PIN col
+    }
+
+    matrix_output_select_delay();
+
+    // For each row...
+    for (uint8_t row_index = 0; row_index < MATRIX_ROWS; row_index++) {
+        // Check row pin state
+        if (readMatrixPin(row_pins[row_index]) == 0) {
+            // Pin LO, set col bit
+            current_matrix[row_index] |= row_shifter;
+            key_pressed = true;
+        } else {
+            // Pin HI, clear col bit
+            current_matrix[row_index] &= ~row_shifter;
+        }
+    }
+
+    // Unselect col
+    unselect_col(current_col);
+    matrix_output_unselect_delay(current_col, key_pressed); // wait for all Row signals to go HIGH
+}
+
+void matrix_init_custom(void) {
+    setPinOutput(HC595_DS);
+    setPinOutput(HC595_STCP);
+    setPinOutput(HC595_SHCP);
+
+    for (uint8_t x = 0; x < MATRIX_ROWS; x++) {
+        if (row_pins[x] != NO_PIN) {
+            setPinInput_high(row_pins[x]);
+        }
+    }
+
+    unselect_cols();
+}
+
+bool matrix_scan_custom(matrix_row_t current_matrix[]) {
+    matrix_row_t curr_matrix[MATRIX_ROWS] = {0};
+
+    // Set col, read rows
+    matrix_row_t row_shifter = MATRIX_ROW_SHIFTER;
+    for (uint8_t current_col = 0; current_col < MATRIX_COLS; current_col++, row_shifter <<= 1) {
+        matrix_read_rows_on_col(curr_matrix, current_col, row_shifter);
+    }
+
+    bool changed = memcmp(current_matrix, curr_matrix, sizeof(curr_matrix)) != 0;
+    if (changed) memcpy(current_matrix, curr_matrix, sizeof(curr_matrix));
+
+    return changed;
+}