Clean up enable pin handling.

This includes:

- Initialize them in mendel.c.

- While running, switch the pin only.

- Sort mendel.c the same order as in pinio.h.

- Remove the requirement of a parameter for this flag, like
  it's with all other flags.

mendel.c

@@ -67,16 +67,6 @@ void io_init(void) {
 
 	// setup I/O pins
 
-	// Common Stepper Enable
-	#ifdef STEPPER_ENABLE_PIN
-		#ifdef STEPPER_ENABLE_INVERT
-			WRITE(STEPPER_ENABLE_PIN, 0);
-		#else
-			WRITE(STEPPER_ENABLE_PIN, 1);
-		#endif
-		SET_OUTPUT(STEPPER_ENABLE_PIN);
-	#endif
-
 	// X Stepper
 	WRITE(X_STEP_PIN, 0);	SET_OUTPUT(X_STEP_PIN);
 	WRITE(X_DIR_PIN,  0);	SET_OUTPUT(X_DIR_PIN);
@@ -96,9 +86,6 @@ void io_init(void) {
 			WRITE(X_MAX_PIN, 0);
 		#endif
 	#endif
-	#ifdef X_ENABLE_PIN
-		WRITE(X_ENABLE_PIN, 1); SET_OUTPUT(X_ENABLE_PIN);
-	#endif
 
 	// Y Stepper
 	WRITE(Y_STEP_PIN, 0);	SET_OUTPUT(Y_STEP_PIN);
@@ -119,9 +106,6 @@ void io_init(void) {
 			WRITE(Y_MAX_PIN, 0);
 		#endif
 	#endif
-	#ifdef Y_ENABLE_PIN
-		WRITE(Y_ENABLE_PIN, 1); SET_OUTPUT(Y_ENABLE_PIN);
-	#endif
 
 	// Z Stepper
 	#if defined Z_STEP_PIN && defined Z_DIR_PIN
@@ -144,16 +128,60 @@ void io_init(void) {
 			WRITE(Z_MAX_PIN, 0);
 		#endif
 	#endif
-	#ifdef Z_ENABLE_PIN
-		WRITE(Z_ENABLE_PIN, 1); SET_OUTPUT(Z_ENABLE_PIN);
-	#endif
 
 	#if defined E_STEP_PIN && defined E_DIR_PIN
 		WRITE(E_STEP_PIN, 0);	SET_OUTPUT(E_STEP_PIN);
 		WRITE(E_DIR_PIN,  0);	SET_OUTPUT(E_DIR_PIN);
 	#endif
+
+	// Common Stepper Enable
+	#ifdef STEPPER_ENABLE_PIN
+		#ifdef STEPPER_ENABLE_INVERT
+			WRITE(STEPPER_ENABLE_PIN, 0);
+		#else
+			WRITE(STEPPER_ENABLE_PIN, 1);
+		#endif
+		SET_OUTPUT(STEPPER_ENABLE_PIN);
+	#endif
+
+	// X Stepper Enable
+	#ifdef X_ENABLE_PIN
+		#ifdef X_INVERT_ENABLE
+			WRITE(X_ENABLE_PIN, 0);
+		#else
+			WRITE(X_ENABLE_PIN, 1);
+		#endif
+		SET_OUTPUT(X_ENABLE_PIN);
+	#endif
+
+	// Y Stepper Enable
+	#ifdef Y_ENABLE_PIN
+		#ifdef Y_INVERT_ENABLE
+			WRITE(Y_ENABLE_PIN, 0);
+		#else
+			WRITE(Y_ENABLE_PIN, 1);
+		#endif
+		SET_OUTPUT(Y_ENABLE_PIN);
+	#endif
+
+	// Z Stepper Enable
+	#ifdef Z_ENABLE_PIN
+		#ifdef Z_INVERT_ENABLE
+			WRITE(Z_ENABLE_PIN, 0);
+		#else
+			WRITE(Z_ENABLE_PIN, 1);
+		#endif
+		SET_OUTPUT(Z_ENABLE_PIN);
+	#endif
+
+	// E Stepper Enable
 	#ifdef E_ENABLE_PIN
-		WRITE(E_ENABLE_PIN, 1); SET_OUTPUT(E_ENABLE_PIN);
+		#ifdef E_INVERT_ENABLE
+			WRITE(E_ENABLE_PIN, 0);
+		#else
+			WRITE(E_ENABLE_PIN, 1);
+		#endif
+		SET_OUTPUT(E_ENABLE_PIN);
 	#endif
 
 	// setup PWM timers: fast PWM, no prescaler

pinio.h

@@ -7,22 +7,6 @@
 
 #include	"config.h"
 
-#ifndef	X_INVERT_ENABLE
-	#define	X_INVERT_ENABLE 0
-#endif
-
-#ifndef	Y_INVERT_ENABLE
-	#define	Y_INVERT_ENABLE 0
-#endif
-
-#ifndef	Z_INVERT_ENABLE
-	#define	Z_INVERT_ENABLE 0
-#endif
-
-#ifndef	E_INVERT_ENABLE
-	#define	E_INVERT_ENABLE 0
-#endif
-
 /*
 Power
 */
@@ -169,32 +153,52 @@ Stepper Enable Pins
 #endif
 
 #ifdef	X_ENABLE_PIN
-	#define	x_enable()					do { WRITE(X_ENABLE_PIN, X_INVERT_ENABLE); SET_OUTPUT(X_ENABLE_PIN); } while (0)
+	#ifdef	X_INVERT_ENABLE
-	#define	x_disable()					do { WRITE(X_ENABLE_PIN, X_INVERT_ENABLE ^ 1); SET_OUTPUT(X_ENABLE_PIN); } while (0)
+		#define	x_enable()				do { WRITE(X_ENABLE_PIN, 0); } while (0)
+		#define	x_disable()				do { WRITE(X_ENABLE_PIN, 1); } while (0)
+	#else
+		#define	x_enable()				do { WRITE(X_ENABLE_PIN, 1); } while (0)
+		#define	x_disable()				do { WRITE(X_ENABLE_PIN, 0); } while (0)
+	#endif
 #else
 	#define	x_enable()					do { } while (0)
 	#define	x_disable()					do { } while (0)
 #endif
 
 #ifdef	Y_ENABLE_PIN
-	#define	y_enable()					do { WRITE(Y_ENABLE_PIN, Y_INVERT_ENABLE); SET_OUTPUT(Y_ENABLE_PIN); } while (0)
+	#ifdef	Y_INVERT_ENABLE
-	#define	y_disable()					do { WRITE(Y_ENABLE_PIN, Y_INVERT_ENABLE ^ 1); SET_OUTPUT(Y_ENABLE_PIN); } while (0)
+		#define	y_enable()				do { WRITE(Y_ENABLE_PIN, 0); } while (0)
+		#define	y_disable()				do { WRITE(Y_ENABLE_PIN, 1); } while (0)
+	#else
+		#define	y_enable()				do { WRITE(Y_ENABLE_PIN, 1); } while (0)
+		#define	y_disable()				do { WRITE(Y_ENABLE_PIN, 0); } while (0)
+	#endif
 #else
 	#define	y_enable()					do { } while (0)
 	#define	y_disable()					do { } while (0)
 #endif
 
 #ifdef	Z_ENABLE_PIN
-	#define	z_enable()					do { WRITE(Z_ENABLE_PIN, Z_INVERT_ENABLE); SET_OUTPUT(Z_ENABLE_PIN); } while (0)
+	#ifdef	Z_INVERT_ENABLE
-	#define	z_disable()					do { WRITE(Z_ENABLE_PIN, Z_INVERT_ENABLE ^ 1); SET_OUTPUT(Z_ENABLE_PIN); } while (0)
+		#define	z_enable()				do { WRITE(Z_ENABLE_PIN, 0); } while (0)
+		#define	z_disable()				do { WRITE(Z_ENABLE_PIN, 1); } while (0)
+	#else
+		#define	z_enable()				do { WRITE(Z_ENABLE_PIN, 1); } while (0)
+		#define	z_disable()				do { WRITE(Z_ENABLE_PIN, 0); } while (0)
+	#endif
 #else
 	#define	z_enable()					do { } while (0)
 	#define	z_disable()					do { } while (0)
 #endif
 
 #ifdef	E_ENABLE_PIN
-	#define	e_enable()					do { WRITE(E_ENABLE_PIN, E_INVERT_ENABLE); SET_OUTPUT(E_ENABLE_PIN); } while (0)
+	#ifdef	E_INVERT_ENABLE
-	#define	e_disable()					do { WRITE(E_ENABLE_PIN, E_INVERT_ENABLE ^ 1); SET_OUTPUT(E_ENABLE_PIN); } while (0)
+		#define	e_enable()				do { WRITE(E_ENABLE_PIN, 0); } while (0)
+		#define	e_disable()				do { WRITE(E_ENABLE_PIN, 1); } while (0)
+	#else
+		#define	e_enable()				do { WRITE(E_ENABLE_PIN, 1); } while (0)
+		#define	e_disable()				do { WRITE(E_ENABLE_PIN, 0); } while (0)
+	#endif
 #else
 	#define	e_enable()					do { } while (0)
 	#define	e_disable()					do { } while (0)