This is a rewrite of the Kinetis GPIO driver which follows the
refactored API in [1]. Pins are specified using the GPIO_PIN(PORT_x, y)
macro, e.g. GPIO_PIN(PORT_E, 25) for the PTE25 pin.
The interrupt pin handling is now implemented as a linked list, this
is more memory efficient, but with a minor variation in interrupt
latency depending on in what order the pins were initialized at
runtime.
Because the linked list entries are taken from a shared pool, there is
also the possibility of running out of available configuration slots,
define the preprocessor macro GPIO_INT_POOL_SIZE in periph_conf.h if
you need more than 16 pins configured for interrupts in the same
application.
[1]: https://github.com/RIOT-OS/RIOT/pull/3095
As discussed in #2725, this commit renames a number of stacksize constants to
better convey their intended usage. In addition, constants for thread priority
are given a `THREAD_` prefix. Changes are:
* KERNEL_CONF_STACKSIZE_PRINTF renamed to THREAD_EXTRA_STACKSIZE_PRINTF
* KERNEL_CONF_STACKSIZE_DEFAULT renamed to THREAD_STACKSIZE_DEFAULT
* KERNEL_CONF_STACKSIZE_IDLE renamed to THREAD_STACKSIZE_IDLE
* KERNEL_CONF_STACKSIZE_MAIN renamed to THREAD_STACKSIZE_MAIN
* Move thread stacksizes from kernel.h to thread.h, since the prefix changed
* PRIORITY_MIN renamed to THREAD_PRIORITY_MIN
* PRIORITY_IDLE renamed to THREAD_PRIORITY_IDLE
* PRIORITY_MAIN renamed to THREAD_PRIORITY_MAIN
* Move thread priorities from kernel.h to thread.h since the prefix has changed
* MINIMUM_STACK_SIZE renamed to THREAD_STACKSIZE_MINIMUM for consistency
