Why is my HPS qspi clock interface inverted?

Description

The SoC Hardware Library (HWLIB) configures and controls the SoC Quad Serial Peripheral Interface (SPI) Controllers. The QSPI HWLIB source, can be found in the /ip/altera/hps/altera_hps/hwlib/include/alt_qspi.h file. 

In SOC EDS 15.0 and earlier, the definition of the polarity ALT_QSPI_CLK_POLARITY_LOW and ALT_QSPI_CLK_POLARITY_HIGH and their respective values in alt_qspi.h is incorrect. 

Resolution

To work around this problem, edit alt_qspi.h and replace:
ALT_QSPI_CLK_POLARITY_LOW     = 0
with
ALT_QSPI_CLK_POLARITY_LOW     = 1

and


ALT_QSPI_CLK_POLARITY_HIGH    = 1
with
ALT_QSPI_CLK_POLARITY_ HIGH   = 0

This problem is scheduled be fixed in a future version of the Altera SoC Embedded Design Suite.