Linux/AM5728: TI-AM57xx-EVM

Hi Pavel,

I understand that to enable i need to put below mention statement in linux-kernel/arch/arm/boot/dts/ti/am57xx-evm-common.dtso

&epwmssx {
    status = "okay";
};
&ehrpwmx {
    status = "okay";
    };
where x - 1,2,3

But my main doubt are:

1. Which DTS file need to used to make dtb that can load into target rootfs, As am not able to locate AM57xx-evm.dts file under my compile linux directory mention below, although it has AM57xx-evm.dtb file 

    /ti-processor-sdk-linux-am57xx-evm-05.00.00.15/board-support/linux-4.14.40/arch/arm/boot/dts

 

2. And i also seen there is no such compatibility mention in  pwm-tipwmss.c and pwm-tiehrpwm.c  for TIAM57xx-EVM in drivers. So how these pwm drivers can be utilize in that case.

Akash,

akash garg said:

1. Which DTS file need to used to make dtb that can load into target rootfs, As am not able to locate AM57xx-evm.dts file under my compile linux directory mention below, although it has AM57xx-evm.dtb file 

    /ti-processor-sdk-linux-am57xx-evm-05.00.00.15/board-support/linux-4.14.40/arch/arm/boot/dts

You need to use am57xx-evm.dtso or am57xx-evm-reva3.dtso depending on which version of the EVM you have. See also below user guide:

akash garg said:

2. And i also seen there is no such compatibility mention in  pwm-tipwmss.c and pwm-tiehrpwm.c  for TIAM57xx-EVM in drivers. So how these pwm drivers can be utilize in that case.

AM57x use "ti,dra746-pwmss", "ti,dra746-ehrpwm" and "ti,dra746-ecap". See below file:

linux-kernel/arch/arm/boot/dts/dra7.dtsi

Regards,
Pavel

Hi Pavel,

 Am using AM57xx-Evm revA3 and processor SDK  linux 5.0.0.15. As you suggest i update my am57xx-evm-revA3.dts to enable other PWMSS. 

Previously /sys/class/pwm shows only pwmchip0 that will be used for LCD backlight. After i enable other PWMSS, am able to access pwmchip2 also.

Also able to configure pwm0 & pwm1 for that and there properties like period, duty_cycle.

But not able to debug there output on ehrpwm3A & ehrpwm3B respective pins. 

I configured pin35 and pin37 of P17 connector on EVM as  ehrpwm3A & ehrpwm3B respectively using mux_data.h under uboot.

My main requirement to enable two PWM channel of 100KHz of oppositve polarity.

Akash,

I see you have opened new e2e thread for your new issue, and our PWM expert is helping on this there in your another thread:

e2e.ti.com/.../761768

Please close this thread.

Regards,
Pavel

But issue is not resolved yet. Am still struggling to get desired pwm output. Can i know how to get pin configuration update by doing changes on mux_data.h