Optimizing I2C

[tmk_firmware.git] / keyboard / ergodox / matrix.c

diff --git a/keyboard/ergodox/matrix.c b/keyboard/ergodox/matrix.c
index e35b65c95af4b16410d8a20e410d3b381f2e972c..b75d7c57a038e14ae70955f74717baa02ef7654c 100644 (file)
--- a/keyboard/ergodox/matrix.c
+++ b/keyboard/ergodox/matrix.c
@@ -42,10 +42,12 @@ static uint8_t debouncing = DEBOUNCE;
 static matrix_row_t matrix[MATRIX_ROWS];
 static matrix_row_t matrix_debouncing[MATRIX_ROWS];
 
-static matrix_row_t read_cols(uint8_t mcp23018_status, uint8_t row);
+static matrix_row_t read_cols(uint8_t row);
 static void init_cols(void);
-static void unselect_rows(uint8_t mcp23018_status);
-static void select_row(uint8_t mcp23018_status, uint8_t row);
+static void unselect_rows();
+static void select_row(uint8_t row);
+
+static uint8_t mcp23018_status;
 
 #ifdef DEBUG_MATRIX_FREQ
 uint32_t matrix_timer;
@@ -68,9 +70,8 @@ void matrix_init(void)
 {
     // initialize row and col
     init_ergodox();
-    uint8_t mcp23018_status;
     mcp23018_status = init_mcp23018();
-    unselect_rows(mcp23018_status);
+    unselect_rows();
     init_cols();
 
     // initialize matrix state: all keys off
@@ -139,16 +140,14 @@ uint8_t matrix_scan(void)
     }
 
     // not actually needed because we already calling init_mcp23018() in next line
-    // ergodox_left_leds_update();
+    mcp23018_status = ergodox_left_leds_update();
 
 #endif
 
-    uint8_t mcp23018_status = init_mcp23018();
-
     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
-        select_row(mcp23018_status, i);
+        select_row(i);
         _delay_us(30);  // without this wait read unstable value.
-        matrix_row_t cols = read_cols(mcp23018_status, i);
+        matrix_row_t cols = read_cols(i);
         if (matrix_debouncing[i] != cols) {
             matrix_debouncing[i] = cols;
             if (debouncing) {
@@ -156,7 +155,7 @@ uint8_t matrix_scan(void)
             }
             debouncing = DEBOUNCE;
         }
-        unselect_rows(mcp23018_status);
+        unselect_rows();
     }
 
     if (debouncing) {
@@ -230,17 +229,16 @@ static void  init_cols(void)
     PORTF |=  (1<<7 | 1<<6 | 1<<5 | 1<<4 | 1<<1 | 1<<0);
 }
 
-static matrix_row_t read_cols(uint8_t mcp23018_status, uint8_t row)
+static matrix_row_t read_cols(uint8_t row)
 {
     if (row < 7) {
         if (mcp23018_status) { // if there was an error
             return 0;
         } else {
             uint8_t data = 0;
-            uint8_t err = 0x20;
-            err = i2c_start(I2C_ADDR_WRITE);    if (err) goto out;
-            err = i2c_write(GPIOB);             if (err) goto out;
-            err = i2c_start(I2C_ADDR_READ);     if (err) goto out;
+            mcp23018_status = i2c_start(I2C_ADDR_WRITE);    if (mcp23018_status) goto out;
+            mcp23018_status = i2c_write(GPIOB);             if (mcp23018_status) goto out;
+            mcp23018_status = i2c_start(I2C_ADDR_READ);     if (mcp23018_status) goto out;
             data = i2c_readNak();
             data = ~data;
         out:
@@ -269,19 +267,18 @@ static matrix_row_t read_cols(uint8_t mcp23018_status, uint8_t row)
  * row: 0   1   2   3   4   5   6
  * pin: A0  A1  A2  A3  A4  A5  A6
  */
-static void unselect_rows(uint8_t mcp23018_status)
+static void unselect_rows(void)
 {
     // unselect on mcp23018
     if (mcp23018_status) { // if there was an error
         // do nothing
     } else {
         // set all rows hi-Z : 1
-        uint8_t err = 0x20;
-        err = i2c_start(I2C_ADDR_WRITE);    if (err) goto out;
-        err = i2c_write(GPIOA);             if (err) goto out;
-        err = i2c_write( 0xFF
-                & ~(ergodox_left_led_3<<LEFT_LED_3_SHIFT)
-              );                            if (err) goto out;
+        mcp23018_status = i2c_start(I2C_ADDR_WRITE);    if (mcp23018_status) goto out;
+        mcp23018_status = i2c_write(GPIOA);             if (mcp23018_status) goto out;
+        mcp23018_status = i2c_write( 0xFF
+                              & ~(ergodox_left_led_3<<LEFT_LED_3_SHIFT)
+                          );                            if (mcp23018_status) goto out;
     out:
         i2c_stop();
     }
@@ -296,7 +293,7 @@ static void unselect_rows(uint8_t mcp23018_status)
     PORTC &= ~(1<<6);
 }
 
-static void select_row(uint8_t mcp23018_status, uint8_t row)
+static void select_row(uint8_t row)
 {
     if (row < 7) {
         // select on mcp23018
@@ -305,12 +302,11 @@ static void select_row(uint8_t mcp23018_status, uint8_t row)
         } else {
             // set active row low  : 0
             // set other rows hi-Z : 1
-            uint8_t err = 0x20;
-            err = i2c_start(I2C_ADDR_WRITE);        if (err) goto out;
-            err = i2c_write(GPIOA);                 if (err) goto out;
-            err = i2c_write( 0xFF & ~(1<<row) 
-                    & ~(ergodox_left_led_3<<LEFT_LED_3_SHIFT)
-                  );                                if (err) goto out;
+            mcp23018_status = i2c_start(I2C_ADDR_WRITE);        if (mcp23018_status) goto out;
+            mcp23018_status = i2c_write(GPIOA);                 if (mcp23018_status) goto out;
+            mcp23018_status = i2c_write( 0xFF & ~(1<<row) 
+                                  & ~(ergodox_left_led_3<<LEFT_LED_3_SHIFT)
+                              );                                if (mcp23018_status) goto out;
         out:
             i2c_stop();
         }