[QUESTION] PPC4xx SPI mode

Herrera-Bendezu, Luis lherrera at harris.com
Thu Jan 29 11:08:11 EST 2009


I am using PPC440EPx SPI driver to access devices with different clock
polarities (SPI_MODE_0 and SPI_MODE_2), but otherwise similar SPI
parameters (max clock frequency, bits per word, etc.) If spidev is
used to modify clock polarity via ioctl SPI_IOC_WR_MODE, it does not
have any effect on the controller.

This list has dicussed a related issue:
http://ozlabs.org/pipermail/linuxppc-dev/2009-January/066749.html

that explains why SPI_IOC_WR_MODE does not work, function
spi_ppc4xx_setupxfer() is called only once by spi_ppc4xx_setup()
function. Any subsequent call just ignores request to change SPI
configuration and does not report any error.

Is this how the driver is supposed to work?
Can the above usage be acommodated into the driver?

Thanks,
Luis





More information about the Linuxppc-dev mailing list