SPI_BUS_LOCK(9) Serial Peripheral Interface (S SPI_BUS_LOCK(9)NAMEspi_bus_lock - obtain a lock for exclusive SPI bus usage
SYNOPSIS
int spi_bus_lock(struct spi_master * master);
ARGUMENTS
master
SPI bus master that should be locked for exclusive bus access
CONTEXT
can sleep
DESCRIPTION
This call may only be used from a context that may sleep. The sleep is
non-interruptible, and has no timeout.
This call should be used by drivers that require exclusive access to
the SPI bus. The SPI bus must be released by a spi_bus_unlock call when
the exclusive access is over. Data transfer must be done by
spi_sync_locked and spi_async_locked calls when the SPI bus lock is
held.
It returns zero on success, else a negative error code.
COPYRIGHTKernel Hackers Manual 3.8. June 2014 SPI_BUS_LOCK(9)