SPI_SYNC(9)                       Serial Peripheral Interface (S                      SPI_SYNC(9)



NAME
       spi_sync - blocking/synchronous SPI data transfers

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

ARGUMENTS
       spi
           device with which data will be exchanged

       message
           describes the data transfers

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. Low-overhead controller drivers may DMA directly into and out of the
       message buffers.

       Note that the SPI device's chip select is active during the message, and then is normally
       disabled between messages. Drivers for some frequently-used devices may want to minimize
       costs of selecting a chip, by leaving it selected in anticipation that the next message
       will go to the same chip. (That may increase power usage.)

       Also, the caller is guaranteeing that the memory associated with the message will not be
       freed before this call returns.

RETURN
       zero on success, else a negative error code.

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