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.