Fix LPC178x I2C mode GPIO configuration

arch/arm/src/lpc17xx/chip/lpc178x_iocon.h

@@ -348,17 +348,17 @@
 
 /* Slew rate modes */
 
-#define IOCON_SLEWMODE_NORMAL      (0 << IOCON_SLEW_SHIFT)
-#define IOCON_SLEWMODE_FAST        (1 << IOCON_SLEW_SHIFT)
+#define IOCON_SLEWMODE_NORMAL       (0 << IOCON_SLEW_SHIFT)
+#define IOCON_SLEWMODE_FAST         (1 << IOCON_SLEW_SHIFT)
 
 /* I2C modes */
 
-#define IOCON_I2CMODE_SHIFT        (IOCON_I2CHS_SHIFT)
-#define IOCON_I2CMODE_MASK         (3 << IOCON_I2CMODE_SHIFT)
-#define IOCON_I2CMODE_FAST         (0 << IOCON_I2CMODE_SHIFT)
-#define IOCON_I2CMODE_FASTPLUS     (1 << IOCON_I2CMODE_SHIFT)/*   */
-#define IOCON_I2CMODE_HIOPENDRAIN  (2 << IOCON_I2CMODE_SHIFT)/*  */
-#define IOCON_I2CMODE_OPENDRAIN    (3 << IOCON_I2CMODE_SHIFT)/*  */
+#define IOCON_I2CMODE_SHIFT         (IOCON_I2CHS_SHIFT)
+#define IOCON_I2CMODE_MASK          (3 << IOCON_I2CMODE_SHIFT)
+#  define IOCON_I2CMODE_FAST        (0 << IOCON_I2CMODE_SHIFT)
+#  define IOCON_I2CMODE_FASTPLUS    (1 << IOCON_I2CMODE_SHIFT)/*   */
+#  define IOCON_I2CMODE_HIOPENDRAIN (2 << IOCON_I2CMODE_SHIFT)/*  */
+#  define IOCON_I2CMODE_OPENDRAIN   (3 << IOCON_I2CMODE_SHIFT)/*  */
 
 /************************************************************************************
  * Public Types

arch/arm/src/lpc17xx/lpc178x_gpio.c

@@ -803,9 +803,9 @@ static int lpc17_configalternate(lpc17_pinset_t cfgset, unsigned int port,
 
   if ((cfgset & (GPIO_I2CHS | GPIO_HIDRIVE)) != 0)
     {
-	  /* WARNING:  Using literal values (14) is a maintenance problem */
+      /* Isolate the I2C mode bits */
 
-      i2cmode = ((cfgset & (GPIO_I2CHS | GPIO_HIDRIVE)) >> 14);
+      i2cmode = ((cfgset & GPIO_I2CMODE_MASK) >> GPIO_I2CMODE_SHIFT);
 
       /* Set I2C Modes */
 

arch/arm/src/lpc17xx/lpc178x_gpio.h

@@ -67,8 +67,11 @@
 #  define GPIO_ADMODE          (1 << 19) /* Bit 19: A/D Modes: 0-Analog, 1-Digital  */
 #  define GPIO_FILTER          (1 << 20) /* Bit 20: Filter: 0-Off, 1-ON */
 #  define GPIO_DACEN           (1 << 21) /* Bit 21: DAC: 0-Disabled, 1-Enabled, P0:26 only */
-#  define GPIO_I2CHS           (1 << 22) /* Bit 22: Filter and Rate Control: 0-Enabled, 1-Disabled */
-#  define GPIO_HIDRIVE         (1 << 23) /* Bit 23: Current Sink: 0-4mA, 1-20mA  P5:2 and P5:3 only,*/
+
+#  define GPIO_I2CMODE_SHIFT   (22)      /* Bits 22-23: I2C mode */
+#  define GPIO_I2CMODE_MASK    (3 << GPIO_I2CMODE_SHIFT)
+#    define GPIO_I2CHS         (1 << 22) /* Bit 22: Filter and Rate Control: 0-Enabled, 1-Disabled */
+#    define GPIO_HIDRIVE       (1 << 23) /* Bit 23: Current Sink: 0-4mA, 1-20mA  P5:2 and P5:3 only,*/
 
 /* Pin Function bits: FFFF
  * Only meaningful when the GPIO function is GPIO_PIN