Function gpio_lower_half_byname() was added to support registration of
GPIO pin by name as supported for IOexpander. Some of the code is wrapped
in new static function gpio_lower_half_internal() to avoid code
duplication.
Signed-off-by: Michal Lenc <michallenc@seznam.cz>
* Simplify EINTR/ECANCEL error handling
1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx
* Unify the void cast usage
1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
driver/ioexpander: Add gpio_pin_unregister function to GPIO driver
driver/ioexpander: Add pinset struct to GPIO driver for interrupt pins larger than 64
driver/ioexpander: Initialize pintype/inttype when registering ioexpander device
driver/ioexpander: Add SETPINTYPE ioctl command to the GPIO driver
