1 files changed, 120 insertions, 0 deletions
diff --git a/keyboards/ergodox/ergodone/expander.c b/keyboards/ergodox/ergodone/expander.c
new file mode 100644
index 0000000000..0c8a2289c5
--- /dev/null
+++ b/keyboards/ergodox/ergodone/expander.c
@@ -0,0 +1,120 @@
+#include <stdbool.h>
+#include "action.h"
+#include "i2cmaster.h"
+#include "expander.h"
+#include "debug.h"
+
+static uint8_t expander_status = 0;
+static uint8_t expander_input = 0;
+
+void expander_config(void);
+uint8_t expander_write(uint8_t reg, uint8_t data);
+uint8_t expander_read(uint8_t reg, uint8_t *data);
+
+void expander_init(void)
+{
+  i2c_init();
+  expander_scan();
+}
+
+void expander_scan(void)
+{
+  dprintf("expander status: %d ... ", expander_status);
+  uint8_t ret = i2c_start(EXPANDER_ADDR | I2C_WRITE);
+  if (ret == 0) {
+    i2c_stop();
+    if (expander_status == 0) {
+      dprintf("attached\n");
+      expander_status = 1;
+      expander_config();
+      clear_keyboard();
+    }
+  }
+  else {
+    if (expander_status == 1) {
+      dprintf("detached\n");
+      expander_status = 0;
+      clear_keyboard();
+    }
+  }
+  dprintf("%d\n", expander_status);
+}
+
+void expander_read_cols(void)
+{
+  expander_read(EXPANDER_REG_GPIOA, &expander_input);
+}
+
+uint8_t expander_get_col(uint8_t col)
+{
+  if (col > 4) {
+    col++;
+  }
+  return expander_input & (1<<col) ? 1 : 0;
+}
+
+matrix_row_t expander_read_row(void)
+{
+  expander_read_cols();
+
+  /* make cols */
+  matrix_row_t cols = 0;
+  for (uint8_t col = 0; col < MATRIX_COLS; col++) {
+    if (expander_get_col(col)) {
+      cols |= (1UL << (MATRIX_COLS - 1 - col));
+    }
+  }
+
+  return cols;
+}
+
+void expander_unselect_rows(void)
+{
+  expander_write(EXPANDER_REG_IODIRB, 0xFF);
+}
+
+void expander_select_row(uint8_t row)
+{
+  expander_write(EXPANDER_REG_IODIRB, ~(1<<(row+1)));
+}
+
+void expander_config(void)
+{
+  expander_write(EXPANDER_REG_IPOLA, 0xFF);
+  expander_write(EXPANDER_REG_GPPUA, 0xFF);
+  expander_write(EXPANDER_REG_IODIRB, 0xFF);
+}
+
+uint8_t expander_write(uint8_t reg, uint8_t data)
+{
+  if (expander_status == 0) {
+    return 0;
+  }
+  uint8_t ret;
+  ret = i2c_start(EXPANDER_ADDR | I2C_WRITE);
+  if (ret) goto stop;
+  ret = i2c_write(reg);
+  if (ret) goto stop;
+  ret = i2c_write(data);
+ stop:
+  i2c_stop();
+  return ret;
+}
+
+uint8_t expander_read(uint8_t reg, uint8_t *data)
+{
+  if (expander_status == 0) {
+    return 0;
+  }
+  uint8_t ret;
+  ret = i2c_start(EXPANDER_ADDR | I2C_WRITE);
+  if (ret) goto stop;
+  ret = i2c_write(reg);
+  if (ret) goto stop;
+  ret = i2c_rep_start(EXPANDER_ADDR | I2C_READ);
+  if (ret) goto stop;
+  *data = i2c_readNak();
+ stop:
+  i2c_stop();
+  return ret;
+}