5 files changed, 35 insertions, 31 deletions

diff --git a/drivers/avr/i2c_master.c b/drivers/avr/i2c_master.c
index 30ea760c9..f25e354b8 100755
--- a/drivers/avr/i2c_master.c
+++ b/drivers/avr/i2c_master.c
@@ -28,7 +28,7 @@ i2c_status_t i2c_start(uint8_t address, uint16_t timeout)
 
   uint16_t timeout_timer = timer_read();
   while( !(TWCR & (1<<TWINT)) ) {
-    if (timeout && ((timer_read() - timeout_timer) > timeout)) {
+    if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
   }
@@ -43,7 +43,7 @@ i2c_status_t i2c_start(uint8_t address, uint16_t timeout)
 
   timeout_timer = timer_read();
   while( !(TWCR & (1<<TWINT)) ) {
-    if (timeout && ((timer_read() - timeout_timer) > timeout)) {
+    if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
   }
@@ -64,7 +64,7 @@ i2c_status_t i2c_write(uint8_t data, uint16_t timeout)
 
   uint16_t timeout_timer = timer_read();
   while( !(TWCR & (1<<TWINT)) ) {
-    if (timeout && ((timer_read() - timeout_timer) > timeout)) {
+    if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
   }
@@ -82,7 +82,7 @@ int16_t i2c_read_ack(uint16_t timeout)
 
   uint16_t timeout_timer = timer_read();
   while( !(TWCR & (1<<TWINT)) ) {
-    if (timeout && ((timer_read() - timeout_timer) > timeout)) {
+    if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
   }
@@ -99,7 +99,7 @@ int16_t i2c_read_nack(uint16_t timeout)
 
   uint16_t timeout_timer = timer_read();
   while( !(TWCR & (1<<TWINT)) ) {
-    if (timeout && ((timer_read() - timeout_timer) > timeout)) {
+    if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
   }
@@ -210,7 +210,7 @@ i2c_status_t i2c_stop(uint16_t timeout)
 
   uint16_t timeout_timer = timer_read();
   while(TWCR & (1<<TWSTO)) {
-    if (timeout && ((timer_read() - timeout_timer) > timeout)) {
+    if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) {
       return I2C_STATUS_TIMEOUT;
     }
   }
diff --git a/drivers/avr/i2c_master.h b/drivers/avr/i2c_master.h
index 0806d76aa..cf93680be 100755
--- a/drivers/avr/i2c_master.h
+++ b/drivers/avr/i2c_master.h
@@ -14,6 +14,9 @@ typedef int16_t i2c_status_t;
 #define I2C_STATUS_ERROR   (-1)
 #define I2C_STATUS_TIMEOUT (-2)
 
+#define I2C_TIMEOUT_IMMEDIATE (0)
+#define I2C_TIMEOUT_INFINITE (0xFFFF)
+
 void i2c_init(void);
 i2c_status_t i2c_start(uint8_t address, uint16_t timeout);
 i2c_status_t i2c_write(uint8_t data, uint16_t timeout);
diff --git a/keyboards/ergodox_ez/ergodox_ez.c b/keyboards/ergodox_ez/ergodox_ez.c
index 65671b38f..61f910711 100644
--- a/keyboards/ergodox_ez/ergodox_ez.c
+++ b/keyboards/ergodox_ez/ergodox_ez.c
@@ -22,7 +22,6 @@ extern inline void ergodox_right_led_set(uint8_t led, uint8_t n);
 
 extern inline void ergodox_led_all_set(uint8_t n);
 
-
 bool i2c_initialized = 0;
 i2c_status_t mcp23018_status = 0x20;
 
@@ -125,23 +124,23 @@ uint8_t init_mcp23018(void) {
     // - unused  : input  : 1
     // - input   : input  : 1
     // - driving : output : 0
-    mcp23018_status = i2c_start(I2C_ADDR_WRITE, 0);    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(IODIRA, 0);            if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b00000000, 0);        if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b00111111, 0);        if (mcp23018_status) goto out;
-    i2c_stop(0);
+    mcp23018_status = i2c_start(I2C_ADDR_WRITE, ERGODOX_EZ_I2C_TIMEOUT);    if (mcp23018_status) goto out;
+    mcp23018_status = i2c_write(IODIRA, ERGODOX_EZ_I2C_TIMEOUT);            if (mcp23018_status) goto out;
+    mcp23018_status = i2c_write(0b00000000, ERGODOX_EZ_I2C_TIMEOUT);        if (mcp23018_status) goto out;
+    mcp23018_status = i2c_write(0b00111111, ERGODOX_EZ_I2C_TIMEOUT);        if (mcp23018_status) goto out;
+    i2c_stop(ERGODOX_EZ_I2C_TIMEOUT);
 
     // set pull-up
     // - unused  : on  : 1
     // - input   : on  : 1
     // - driving : off : 0
-    mcp23018_status = i2c_start(I2C_ADDR_WRITE, 0);    if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(GPPUA, 0);             if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b00000000, 0);        if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(0b00111111, 0);        if (mcp23018_status) goto out;
+    mcp23018_status = i2c_start(I2C_ADDR_WRITE, ERGODOX_EZ_I2C_TIMEOUT);    if (mcp23018_status) goto out;
+    mcp23018_status = i2c_write(GPPUA, ERGODOX_EZ_I2C_TIMEOUT);             if (mcp23018_status) goto out;
+    mcp23018_status = i2c_write(0b00000000, ERGODOX_EZ_I2C_TIMEOUT);        if (mcp23018_status) goto out;
+    mcp23018_status = i2c_write(0b00111111, ERGODOX_EZ_I2C_TIMEOUT);        if (mcp23018_status) goto out;
 
 out:
-    i2c_stop(0);
+    i2c_stop(ERGODOX_EZ_I2C_TIMEOUT);
 
 #ifdef LEFT_LEDS
     if (!mcp23018_status) mcp23018_status = ergodox_left_leds_update();
@@ -165,22 +164,22 @@ uint8_t ergodox_left_leds_update(void) {
     // - unused  : hi-Z : 1
     // - input   : hi-Z : 1
     // - driving : hi-Z : 1
-    mcp23018_status = i2c_start(I2C_ADDR_WRITE, 0);
+    mcp23018_status = i2c_start(I2C_ADDR_WRITE, ERGODOX_EZ_I2C_TIMEOUT);
     if (mcp23018_status) goto out;
-    mcp23018_status = i2c_write(OLATA, 0);
+    mcp23018_status = i2c_write(OLATA, ERGODOX_EZ_I2C_TIMEOUT);
     if (mcp23018_status) goto out;
     mcp23018_status = i2c_write(0b11111111
                                 & ~(ergodox_left_led_3<<LEFT_LED_3_SHIFT),
-                                0);
+                                ERGODOX_EZ_I2C_TIMEOUT);
     if (mcp23018_status) goto out;
     mcp23018_status = i2c_write(0b11111111
                                 & ~(ergodox_left_led_2<<LEFT_LED_2_SHIFT)
                                 & ~(ergodox_left_led_1<<LEFT_LED_1_SHIFT),
-                                0);
+                                ERGODOX_EZ_I2C_TIMEOUT);
     if (mcp23018_status) goto out;
 
  out:
-    i2c_stop(0);
+    i2c_stop(ERGODOX_EZ_I2C_TIMEOUT);
     return mcp23018_status;
 }
 #endif
diff --git a/keyboards/ergodox_ez/ergodox_ez.h b/keyboards/ergodox_ez/ergodox_ez.h
index 9086db2fb..641030495 100644
--- a/keyboards/ergodox_ez/ergodox_ez.h
+++ b/keyboards/ergodox_ez/ergodox_ez.h
@@ -24,6 +24,7 @@
 #define OLATB           0x15
 
 extern i2c_status_t mcp23018_status;
+#define ERGODOX_EZ_I2C_TIMEOUT 100
 
 void init_ergodox(void);
 void ergodox_blink_all_leds(void);
diff --git a/keyboards/ergodox_ez/matrix.c b/keyboards/ergodox_ez/matrix.c
index d8b708a16..2e95c83b6 100644
--- a/keyboards/ergodox_ez/matrix.c
+++ b/keyboards/ergodox_ez/matrix.c
@@ -295,13 +295,14 @@ static matrix_row_t read_cols(uint8_t row)
             return 0;
         } else {
             uint8_t data = 0;
-            mcp23018_status = i2c_start(I2C_ADDR_WRITE, 0);    if (mcp23018_status) goto out;
-            mcp23018_status = i2c_write(GPIOB, 0);             if (mcp23018_status) goto out;
-            mcp23018_status = i2c_start(I2C_ADDR_READ, 0);     if (mcp23018_status) goto out;
-            mcp23018_status = i2c_read_nack(0);                if (mcp23018_status < 0) goto out;
+            mcp23018_status = i2c_start(I2C_ADDR_WRITE, ERGODOX_EZ_I2C_TIMEOUT);    if (mcp23018_status) goto out;
+            mcp23018_status = i2c_write(GPIOB, ERGODOX_EZ_I2C_TIMEOUT);             if (mcp23018_status) goto out;
+            mcp23018_status = i2c_start(I2C_ADDR_READ, ERGODOX_EZ_I2C_TIMEOUT);     if (mcp23018_status) goto out;
+            mcp23018_status = i2c_read_nack(ERGODOX_EZ_I2C_TIMEOUT);                if (mcp23018_status < 0) goto out;
             data = ~((uint8_t)mcp23018_status);
+            mcp23018_status = I2C_STATUS_SUCCESS;
         out:
-            i2c_stop(0);
+            i2c_stop(ERGODOX_EZ_I2C_TIMEOUT);
             return data;
         }
     } else {
@@ -350,11 +351,11 @@ static void select_row(uint8_t row)
         } else {
             // set active row low  : 0
             // set other rows hi-Z : 1
-            mcp23018_status = i2c_start(I2C_ADDR_WRITE, 0);        if (mcp23018_status) goto out;
-            mcp23018_status = i2c_write(GPIOA, 0);                 if (mcp23018_status) goto out;
-            mcp23018_status = i2c_write(0xFF & ~(1<<row), 0);      if (mcp23018_status) goto out;
+            mcp23018_status = i2c_start(I2C_ADDR_WRITE, ERGODOX_EZ_I2C_TIMEOUT);        if (mcp23018_status) goto out;
+            mcp23018_status = i2c_write(GPIOA, ERGODOX_EZ_I2C_TIMEOUT);                 if (mcp23018_status) goto out;
+            mcp23018_status = i2c_write(0xFF & ~(1<<row), ERGODOX_EZ_I2C_TIMEOUT);      if (mcp23018_status) goto out;
         out:
-            i2c_stop(0);
+            i2c_stop(ERGODOX_EZ_I2C_TIMEOUT);
         }
     } else {
         // select on teensy