AT91 SPI Chip Select and Mode Failure Detetction

["John Eigelaar" <jeigelaar at mweb dot co dot za>]

Hi,

This patch addresses two problems I encountered in the at91 spi driver
recently.

The spi_at91_start_transfer() function used the wrong polarity for
asserting the chip selects.
This caused the relevant never to be selected.

The AT91SAM7S devices have a Mode Failure Detection feature that was not
handled properly
In the driver. This feature supposedly check for valid transitions from
SPI slave to SPI master
mode when configuring the Mode Register. The current driver
implemetation uses GPIO rather than
the builtin peripheral chip select mechanism, which causes a Mode
Failure to be detected every time
the controller is put into master mode. The patch disables the mode
failure detection for all at91 
variants that supports this function.

Regards
John Eigelaar

Attachment: at91-spi.patch
Description: Binary data