How to remove RTC Alarm from PM Wakeup sources

Hi Carlo,

Does the same happen with the Linux package available from Compulab?

linux package from Compulab is based on kernel 3.2 and sleep functionality is not working at all in that kernel.

Is there any way to tell the Cortex_M3 to mask the RTC_Alarm irq?

Carlo

There is this wiki: http://processors.wiki.ti.com/index.php/AM335x_Power_Management_Standby_User%27s_Guide#RTC_wakeup

You could also (maybe easier) stop the RTC early in the bootloader if you don't need it. See section 20.3.5.14 (RTC_CTRL_REG Register (offset = 40h) [reset = 0h]) in the AM335X TRM Rev. K.

the problem is that the internal RTC is disabled (RTC_PWRONRST = VSS), so there's no way to read/write the registers

therefore also rtcwake command does not work

I can not understand what is triggering the RTC alarm irq. Maybe with RTC disabled that signal is floating? Anyway, masking that interrupt on CM3 looks the only solution to me, but I do not know how to do it

Carlo

This would have to be somewhere in the Cortex-M3 firmware, but I am not familiar with it an cannot help I'm afraid.

I downloaded the Cortex-M3 firmware sources, modified them to mask the interrupt, rebuilt the firmware. Made a test, it works! So the RTC alarm irq is somehow really floating when the RTC module is disabled...

Carlo

Carlo, I would also like to run 3.12 on CM-T335.  Was it difficult to get this going?

I'm almost there, but can't figure out how to load the zImage and .dtb -- how did you do this?

you can load them from u-boot console via tftp

setenv fdtaddr 0x83000000
setenv loadaddr 0x82000000
setenv bootfile zImage-cm-t335
setenv fdtfile am335x-cm-t335.dtb

tftp ${loadaddr} ${bootfile} && tftp ${fdtaddr} ${fdtfile}

bootz ${loadaddr} - ${fdtaddr}

Thanks, that works well.  Are you using the onboard wifi?

nope, I'm not using it