Forum Post: RE: Power off for Zoom™ OMAP-L138 EVM - Logic PD

Thanks for your post.

Please refer the below document for Power-Up/Down Sequencing. (POWER_ON signal)

http://www.ti.com/lit/an/slva371b/slva371b.pdf

http://www.ti.com/analog/docs/litabsmultiplefilelist.tsp?literatureNumber=slva371b&docCategoryId=1&familyId=689

The POWER_ON pin (GPIO) should be asserted by application processor (OMAP).

This should be handled in kernel source. Initialize the required GPIO and map following function in kernel source to make the "poweroff" working.

1. Download the PSP source and update linux/arch/arm/mach-davinci/<>evm.c 

2. Initialize the GPIO (POWER_ON) 

3. Map the following function.

    static void <>_poweroff(void)

   {
     #
     #Write the code to implement the poweroff sequence.
     #GPIO control.
     #

    arm_machine_restart('h', NULL);

   }

4. Build and test the "poweroff" function.