Name
spi_bus_unlock — 
     release the lock for exclusive SPI bus usage
 
Arguments
- master
- 
     SPI bus master that was locked for exclusive bus access
     
Description
   This call may only be used from a context that may sleep.  The sleep
   is non-interruptible, and has no timeout.
   
   This call releases an SPI bus lock previously obtained by an spi_bus_lock
   call.