[Gumstix-users] SSP2 conflict?

[Schlansker, K. <ksc...@fo...>]

I'm trying to implement section 8.4.11 of the processor developer's
manual (32-bit i2s emulation using SSP) over the SSP2 port.

I'm configuring the PXA to be in slave mode.  Once I've configured the
SSP registers and enabled the serial link by setting the SSE bit, I
receive one transmit service request interrupt because the transmit fifo
is empty.  I service the interrupt by filling it (which is kind of
pointless since I only care about receiving data, not sending it), and
then I get no more interrupts.

I've scoped out all of the signals and verified that my clocks are
correct and data is being sent.

The SSSR2 register says that the PXA is still "syncing slave
signals" (the SSSR2[CSS] bit is set).  I've tried the notes that suggest
the master device should not send it's frame sync signal until the CSS
bit is clear, but it does not seem to help.


Could there be some conflict with another piece of code that is trying
to use the 2nd serial port?  My setup is a Verdex, netCF-vx, and a
tweener.

Here's how I'm configuring things:

// configure GPIOs
pxa_gpio_mode(GPIO19_SSPSCLK2_IN_MD);
pxa_gpio_mode(GPIO14_SSPSFRM2_IN_MD);
pxa_gpio_mode(GPIO11_SSPRXD2_MD);
pxa_gpio_mode(GPIO13_SSPTXD2_MD);

// disable serial port
SSCR0_P(ssp_port) &= ~SSCR0_SSE;

// configure serial registers
//SSCR0: 0b0000_0000_0001_0000_0000_0000_0011_1111
//SSCR1: 0b0010_0011_1000_0000_0001_0011_0000_0011
//SSPSP: 0b0000_0010_0000_0000_0000_0000_0000_0000

SSCR0_P(ssp_port) = 0x0010003f;
SSCR1_P(ssp_port) = 0x23801303;
SSPSP_P(ssp_port) = 0x02000000;

// enable serial port
SSCR0_P(ssp_port) |= SSCR0_SSE;


It looks like the GPIOs are set correctly:
I'm using GPIO pins 11, 13, 14, & 19:

root@gumstix-custom-verdex:~$
cat /proc/gpio/GPIO11 /proc/gpio/GPIO13 /proc/gpio/GPIO14 /proc/gpio/GPIO19
11      AF2     in      clear
13      AF1     out     clear
14      AF2     in      set
19      AF1     in      clear





Thanks!

--
kyle