SPI_ASYNC_LOCKED(9)               Serial Peripheral Interface (S              SPI_ASYNC_LOCKED(9)



NAME
       spi_async_locked - version of spi_async with exclusive bus usage

SYNOPSIS
       int spi_async_locked(struct spi_device * spi, struct spi_message * message);

ARGUMENTS
       spi
           device with which data will be exchanged

       message
           describes the data transfers, including completion callback

CONTEXT
       any (irqs may be blocked, etc)

DESCRIPTION
       This call may be used in_irq and other contexts which can't sleep, as well as from task
       contexts which can sleep.

       The completion callback is invoked in a context which can't sleep. Before that invocation,
       the value of message->status is undefined. When the callback is issued, message->status
       holds either zero (to indicate complete success) or a negative error code. After that
       callback returns, the driver which issued the transfer request may deallocate the
       associated memory; it's no longer in use by any SPI core or controller driver code.

       Note that although all messages to a spi_device are handled in FIFO order, messages may go
       to different devices in other orders. Some device might be higher priority, or have
       various “hard” access time requirements, for example.

       On detection of any fault during the transfer, processing of the entire message is
       aborted, and the device is deselected. Until returning from the associated message
       completion callback, no other spi_message queued to that device will be processed. (This
       rule applies equally to all the synchronous transfer calls, which are wrappers around this
       core asynchronous primitive.)

RETURN
       zero on success, else a negative error code.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                       SPI_ASYNC_LOCKED(9)