Set the Timer's port pin to a Normal Input (MXC_E_GPIO_IN_MODE_NORMAL).
Set the Timer's port pin output mode to Normal Tristate (MXC_E_GPIO_OUT_MODE_NORMAL_TRISTATE).
Next enable the Timer function for the port pin by setting the Function Select to Timer Capture mode.
CMSIS code snippet follows:
/* Set up Timer 1 for port 2, pin 7, Timer Input Capture Mode */
GPIO_SetInMode(PORT2, PIN7, MXC_E_GPIO_IN_MODE_NORMAL); /* Set P2.7 to Normal Input mode */
GPIO_SetOutMode(PORT2, PIN7, MXC_E_GPIO_OUT_MODE_NORMAL_TRISTATE); /* Set P2.7 to Normal Tristate Output mode */
GPIO_SetFuncSel(PORT2, PIN7, PIN7_FUNC_SEL_TMR1); /* Set up P2.7 as Timer 1 Input Capture */
/* Note: PORT2 is defined as 2, PIN7 is defined as 7 and PIN7_FUNC_SEL_TMR1 is defined as 6 in this code example */
/* Configure Timer 1 for input capture */
....