1 files changed, 80 insertions, 0 deletions
diff --git a/keyboards/matrix/m20add/m20add.c b/keyboards/matrix/m20add/m20add.c
new file mode 100644
index 0000000000..b38dad27cd
--- /dev/null
+++ b/keyboards/matrix/m20add/m20add.c
@@ -0,0 +1,80 @@
+/**
+ * m20add.c
+ */
+
+#include "m20add.h"
+#include "tca6424.h"
+#include "rgb_ring.h"
+#include "i2c_master.h"
+
+void set_pin(uint16_t pin)
+{
+    uint8_t data = tca6424_read_port(GET_PORT(pin));
+    data |= ( 1 << GET_PIN(pin));
+    tca6424_write_port(GET_PORT(pin), data);
+}
+
+void clear_pin(uint16_t pin)
+{
+    uint8_t data = tca6424_read_port(GET_PORT(pin));
+    data &= ~( 1 << GET_PIN(pin));
+    tca6424_write_port(GET_PORT(pin), data);
+}
+
+uint8_t read_pin(uint16_t pin)
+{
+    uint8_t data = tca6424_read_port(GET_PORT(pin));
+    return (data & (1<<GET_PIN(pin))) ? 1 : 0;
+}
+
+void matrix_init_kb(void) {
+#ifdef RGBLIGHT_ENABLE
+    rgb_ring_init();
+#endif
+    matrix_init_user();
+}
+
+void matrix_scan_kb(void) {
+#ifdef RGBLIGHT_ENABLE
+    rgb_ring_task();
+#endif
+    matrix_scan_user();
+}
+
+static uint16_t caps_lock_pin = DEF_PIN(TCA6424_PORT2, 3);
+static uint16_t scroll_lock_pin = DEF_PIN(TCA6424_PORT0, 1);
+
+bool led_update_kb(led_t led_state) {
+    bool res = led_update_user(led_state);
+    if (res) {
+        led_state.caps_lock ? set_pin(caps_lock_pin) : clear_pin(caps_lock_pin);
+        led_state.scroll_lock ? set_pin(scroll_lock_pin) : clear_pin(scroll_lock_pin);
+    }
+    return res;
+}
+
+// override the default implementation to avoid re-initialization
+void i2c_init(void)
+{
+    static bool initialized = false;
+    if (initialized) {
+        return;
+    } else {
+        initialized = true;
+    }
+
+    // Try releasing special pins for a short time
+    palSetPadMode(I2C1_SCL_BANK, I2C1_SCL, PAL_MODE_INPUT);
+    palSetPadMode(I2C1_SDA_BANK, I2C1_SDA, PAL_MODE_INPUT);
+
+    chThdSleepMilliseconds(10);
+    palSetPadMode(I2C1_SCL_BANK, I2C1_SCL, PAL_MODE_ALTERNATE(I2C1_SCL_PAL_MODE) | PAL_STM32_OTYPE_OPENDRAIN);
+    palSetPadMode(I2C1_SDA_BANK, I2C1_SDA, PAL_MODE_ALTERNATE(I2C1_SDA_PAL_MODE) | PAL_STM32_OTYPE_OPENDRAIN);
+}
+
+#define REBOOT_MAGIC 0x41544B42
+void shutdown_user(void)
+{
+    // set the magic number for resetting to the bootloader
+    *(uint32_t *)(&(RTCD1.rtc->BKP0R)) = REBOOT_MAGIC;
+}