* 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
drivers/1wire: add PM hooks and unlink support to sht21 sensor (allowing hot-swappable I2C bus from 1-wire converter)
* drivers/1wire: add PM hook to 1wire bus
* drivers/1wire/ds28e17.c: i2c instance must be zeroed
* drivers/sht21: add unlink support
Unlike most other unlink implementations in NuttX drivers, this one
does not allow any I2C operations after unlink, making it possible to
deallocate the I2C bus.
Approved-by: Gregory Nutt <gnutt@nuttx.org>
Squashed commit of the following:
Author: Gregory Nutt <gnutt@nuttx.org>
Some cosmetic changes from coding style review.
Author: Juha Niskanen <juha.niskanen@haltian.com>
drivers/1wire: add 1-wire subsystem and ds28e17 driver