The iMX 1064 RT has several GPIO peripherals, GPIO1, GPIO2, GPIO3, GPIO4, GPIO5, GPIO6, GPIO7, GPIO8, GPIO9.
In the function GPIO_PinInit(), there is a test to see if the GPIO index is in the range of 1 to 5.
kCLOCK_Gpio1, kCLOCK_Gpio2, kCLOCK_Gpio3, kCLOCK_Gpio4, kCLOCK_Gpio5
It appears that GPIO1-5 require a clock to be enabled for each GPIO, but GPIO6-9 do not.
Which clock is used with GPIO6-9 and when is this clock expected to be enabled?
In reading the Clock Control Module (chapter 13 of reference manual), the ahb_clk_root is the clock root for GPIO6-9.
I have found clock_config.c configures the ahb clock.
Are there any other differences between GPIO1-5 and GPIO6-9 that a developer should be aware of?