• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 98 subscribers
  • Views 422 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

problem writing PINCNTLx registers with linux-2.6..37-psp04.01.00.06.patch2

Gary Green1
Prodigy 90 points


The muxmodes are defined for all of the multiplexed pins in $LINUX/arch/arm/mach-omap2/mux814x.c.  The problem occurs with the two entries in ti814x_muxmodes[] that have NULL in the mode0 position:

223:       _TI814X_MUXENTRY(MLBP_SIG_N, 0,
224:                        NULL, NULL, NULL, NULL,
225:                        NULL, NULL, NULL, "gpio1_08_mux1"),

229:       _TI814X_MUXENTRY(MLBP_DAT_N, 0,
230:                        NULL, NULL, NULL, NULL,
231:                        NULL, NULL, NULL, "gpio1_10_mux1"),

A call to omap_mux_init_signal() to initialize either of these pins fails with a "Could not find signal" error message from _omap_mux_get_by_name().  As far as I can tell, the software uses a <mode0.modeN> naming convention that fails when mode0 is NULL.  To work around this problem, I replaced the first null on line 224 with "pincntl63" and the first nulll on line 230 with "pincntl65".

  • 0
    TI__Expert 6655 points

    Hi Gary,

    If the mux mode0 is NULL then you have to call simply with mux mode name like

    omap_mux_init_signal("gpio1_08_mux1", <flags>);

    Regards

    AnilKumar

    Please mark this Forum post as answered via the Verify Answer button below if it helps answer your question.  Thanks!

  • 0 in reply to Anil
    Prodigy 90 points

    Hi AnilKumar,

    Your response shows how to duplicate the problem.  Please try it.  The code will build okay.  At runtime, you will get an error message that says _omap_get_by_name() could not find "gpio1_08_mux1". 

    Thanks - Gary

  • 0 in reply to Gary Green1
    Prodigy 130 points

    Hi Gary,

    I try your work around and it doesn't work. I'm not able to control the GPIO.

    Do you have another option?

    Thank you.

    Kefil

  • 0 in reply to Kefil Landou
    Prodigy 90 points

    Kefil,

    Can you be a little more specific on the failure mode?  The problem I had was a run-time error message "_omap_get_by_name() could not find "gpio1_08_mux1" when the linux kernel booted.  The modification fixed that problem.  I enabled user mode access to gpios and manually toggled the four GPIOs driving LEDs on my target board.  Then wrote a simple driver to toggle a gpio pin and measure the interrupt latency from the rising edge of the gpio output.  The GPIO pins are working on our target board.

    Thanks - Gary