centos man page for spi_setup

SPI_SETUP(9)						  Serial Peripheral Interface (S					      SPI_SETUP(9)

NAME
       spi_setup - setup SPI mode and clock rate

SYNOPSIS
       int spi_setup(struct spi_device * spi);

ARGUMENTS
       spi
	   the device whose settings are being modified

CONTEXT
       can sleep, and no requests are queued to the device

DESCRIPTION
       SPI protocol drivers may need to update the transfer mode if the device doesn't work with its default. They may likewise need to update
       clock rates or word sizes from initial values. This function changes those settings, and must be called from a context that can sleep.
       Except for SPI_CS_HIGH, which takes effect immediately, the changes take effect the next time the device is selected and data is
       transferred to or from it. When this function returns, the spi device is deselected.

       Note that this call will fail if the protocol driver specifies an option that the underlying controller or its driver does not support. For
       example, not all hardware supports wire transfers using nine bit words, LSB-first wire encoding, or active-high chipselects.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014							      SPI_SETUP(9)