• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 98 subscribers
  • Views 619 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.

DM3730 GPIO_112 not working as input

Joshua Lamiano
Prodigy 30 points
Other Parts Discussed in Thread: DM3730

I’m trying to use a DM3730’s GPIO_112 as an input, yet the input reads as 1 regardless of the actual input signal. Mux configuration in u-boot below:


MUX_VAL(CP(CSI2_DX0),        (IEN  | PTD | DIS | M4)) /* GPIO_112 */\


I can set the actual input low (~0 V) or high (~1.8 V) however under both conditions the OS reports a state of high (1) when the following commands are issued:


# echo 112 > /sys/class/gpio/export
# cat /sys/class/gpio/gpio112/value
1
# cat /sys/class/gpio/gpio112/active_low
0
# cat /sys/class/gpio/gpio112/direction                            
in

This input was previously working when routed to GPIO_22. Is there some configuration step I’m missing?

  • 0
    TI__Guru 65405 points
    Hi Joshua,

    The GPIO configuration is correct but could you share what kind of board you are using? Could you check the schematic whether is there something connected to CSI2_DX0 (gpio112) which could give you value "1".

    BR
    Tsvetolin Shulev
  • 0 in reply to Cvetolin Shulev-XID
    Prodigy 30 points
    Thank for the reply. The board is a custom SOM. The schematic shows that the CSI2_DX0 input to the DM3730 is connected to an output from a PLD (and nowhere else), I'm trying to verify the hardware now.

    Unfortunately I can't look at that pin to confirm the input, but I have the PLD's signal routed to a test pin and it looks solid low on a scope.

    Is there anything else I aught to verify on the TI configuration that might be helpful?
  • 0 in reply to Joshua Lamiano
    TI__Guru 65405 points

    The configuration that you done is enough for gpio configuration. There is nothing specific. The steps for gpio configuration are described at the links below but probably you have read it yet:



    I checked the behaviour of gpio 112 on my dm3730evm board:

    root@dm37x-evm:/sys/class/gpio# echo 112 > export

    root@dm37x-evm:/sys/devices/virtual/gpio/gpio112# cat active_low
    0
    root@dm37x-evm:/sys/devices/virtual/gpio/gpio112# cat direction
    in
    root@dm37x-evm:/sys/devices/virtual/gpio/gpio112# cat value
    0


    BR
    Tsvetolin Shulev

  • 0 in reply to Cvetolin Shulev-XID
    Prodigy 30 points
    The problem seems to have been that the custom board did not connect vdds_csiphy2 by default. Once a supply is connected, the GPIO in that module (GPIO module 4) work as expected.