AM5728: EHRPWM1A OUTPUT is ON and OFF in am5728

Ajay,

I am assuming bb-x15.dtsi is a new dts file you have defined? I have 4.19 based kernel and i do not see that dtsi file.
Did you mean arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi?

You need keep tracing back with the include file starting from dts file and check all the included files to check if some other dtsi file is over-writing your changes.

Best Regards,
Keerthy

Hi Keerthy,

Thanks for reply.

Yes i created new bb-x15.dtsi in arch/arm/boot/dts/bb-x15.dtsi. All required changes done in that file.but my question same as default complied 

files affects this changes.?

i check all file No one affect the my file.

for your information i can share i video of PWM output which fluctuation the result.

My main focus on pwm output  which is not get correctly.

I try for ehrpwm1A, ehrpwm1b,ehrpwm2A and ehrpwm2B will same result output is come but Not get continuous result.

Please help me.

Regarding

Ajay 

Hi Keerthy,

Thanks for reply.

For better understanding the issue. I can share the video of PWM output which Discontinuous waveform in output of ehrpwm1A pin.

I try for ehrpwm1A, ehrpwm1b,ehrpwm2A and ehrpwm2B will get same result of output.

Please help me.

Regarding

Ajay 

Ajay,

Can you help us with the values that you are programming into sysfs nodes?

what are the period, duty cycle and polarity values?

Can you try something like period of 1 second with 50% duty cycle and also set the same on x & y axis of your
scope and capture the video?

- Keerthy

i Keerthy,

Thanks you so much for quick reply.
Its working fine with 1KHz frequency and 50% duty cycle but other value of duty cycle likes 5% 10% and 90%.It work for sometime and periodically goes to zero.
Example:for 1KHz frequency and 5% duty_cycle.
echo 1000000 > period
echo 50000 > duty_cycle
echo 1 > enable
Please find attached video with 1KHz frequency and 5% duty cycle. and let us know if have any suggestion regarding this issue.

Thanks.
Ajay

Ajay,

Thanks for the data points!

Can you also confirm with 0 duty cycle that it always stays high and vice versa where in it always stays low.
Also what are the x-axis/y-axis units on the scope?

- Keerthy

Hi keerthy,

Thanks for quick reply.

I also checked with 0% and 100% duty cycle.it works low for 0% and high for 100% duty cycle.

Thanks

Ajay

Thanks for all the testing Ajay. So issue is always with 5%, 10% duty cycle. What is  your requirement? You want to program any random
duty cycle percentage?

- Keerthy

Hi keerthy ,

Thank you got quick responses.

Yes ,Requirement is to run pwm with different period and duty cycle. Right now we are focusing on 10% and 5 % duty cycle with 1khz frequency.

Next we want to try for 100khz 10% and 20% duty cycle.

Please help us to resolve this issue with 1khz.

Thanks

Ajay

Ajay,

One suspect is smart idle mode. Can you try the diff and see if it helps:

git diff arch/arm/mach-omap2/omap_hwmod_7xx_data.c
diff --git a/arch/arm/mach-omap2/omap_hwmod_7xx_data.c b/arch/arm/mach-omap2/omap_hwmod_7xx_data.c
index 6321258535..1398dfe904 100644
--- a/arch/arm/mach-omap2/omap_hwmod_7xx_data.c
+++ b/arch/arm/mach-omap2/omap_hwmod_7xx_data.c
@@ -541,7 +541,7 @@ static struct omap_hwmod_class_sysconfig dra7xx_epwmss_sysc = {
        .sysc_offs      = 0x4,
        .sysc_flags     = SYSC_HAS_SIDLEMODE | SYSC_HAS_SOFTRESET |
                          SYSC_HAS_RESET_STATUS,
-       .idlemodes      = (SIDLE_FORCE | SIDLE_NO | SIDLE_SMART),
+       .idlemodes      = (SIDLE_FORCE | SIDLE_NOT),
        .sysc_fields    = &omap_hwmod_sysc_type2,
 };
 
Regards,
Keerthy

Hi Keerthy,

Thanks for reply.

Currently Digital oscilloscope is not available. It's available in next weeks. I will check and inform you.

Thanks for Help

Thanks

AJay