Add splitkb.com's Elora (#22557)

* Add splitkb's Elora

* WIP

* Make requested changes

* fix missing call to keyboard init user for elora

* sync vial_qmk with qmk

* Add fixes

* Add encoder quadrature and update files

* Update Readme

* Implement changes

* Remove encoder driver from keyboard.json

* make requested changed

* Implement changes and remove myriad_task as it wasn't actually doing anything.

* Remove myriad.h from matrix.c

* Simplify OLED code debug

* Update RGB keycodes (qmk#24484)

* remove rules.mk (qmk#23281)

* Add matrix state sync

---------

Co-authored-by: NapOli1084 <10320176+NapOli1084@users.noreply.github.com>
Co-authored-by: harveysch <126267034+harvey-splitkb@users.noreply.github.com>
Co-authored-by: harvey <harvey@splitkb.com>
Co-authored-by: VeyPatch <126267034+VeyPatch@users.noreply.github.com>

1 files changed, 57 insertions, 0 deletions

diff --git a/keyboards/splitkb/elora/rev1/matrix.c b/keyboards/splitkb/elora/rev1/matrix.c
new file mode 100644
index 0000000000..625eafcd85
--- /dev/null
+++ b/keyboards/splitkb/elora/rev1/matrix.c
@@ -0,0 +1,57 @@
+// Copyright 2024 splitkb.com (support@splitkb.com)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "matrix.h"
+#include "spi_master.h"
+
+// The matrix is hooked up to a chain of 74xx165 shift registers.
+// Pin F0 acts as Chip Select (active-low)
+// The signal goes to a NOT gate, whose output is wired to
+// a) the latch pin of the shift registers
+// b) the "enable" pin of a tri-state buffer,
+//    attached between the shift registers and MISO
+// F0 has an external pull-up.
+// SCK works as usual.
+//
+// Note that the matrix contains a variety of data.
+// In addition to the keys, it also reads the rotary encoders
+// and whether the board is the left/right half.
+
+void matrix_init_custom(void) {
+    // Note: `spi_init` has already been called
+    // in `keyboard_pre_init_kb()`, so nothing to do here
+}
+
+bool matrix_scan_custom(matrix_row_t current_matrix[]) {
+    // Enough to hold the shift registers
+    uint16_t length = 5;
+    uint8_t  data[length];
+
+    // Matrix SPI config
+    // 1) Pin
+    // 2) Mode: Register shifts on rising clock, and clock idles low
+    //      pol = 0 & pha = 0 => mode 0
+    // 3) LSB first: Register outputs H first, and we want H as MSB,
+    //      as this result in a neat A-H order in the layout macro.
+    // 4) Divisor: 2 is the fastest possible, at Fclk / 2.
+    //      range is 2-128
+    spi_start(GP13, false, 0, 128);
+    spi_receive(data, length);
+    spi_stop();
+
+    bool matrix_has_changed = false;
+    for (uint8_t i = 0; i < length; i++) {
+        // Bitwise NOT because we use pull-ups,
+        // and switches short the pin to ground,
+        // but the matrix uses 1 to indicate a pressed switch
+        uint8_t word = ~data[i];
+        matrix_has_changed |= current_matrix[i] ^ word;
+        current_matrix[i] = word;
+    }
+#ifdef MYRIAD_ENABLE
+    bool myriad_hook_matrix(matrix_row_t current_matrix[]);
+    return matrix_has_changed || myriad_hook_matrix(current_matrix);
+#else
+    return matrix_has_changed;
+#endif
+}
\ No newline at end of file