imx233 - micro pwm

Started by FET_Destroyer, March 21, 2015, 07:33:46 pm

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FET_Destroyer

Hello guys,

I'm newbie to olinuxino but i've done somethings in the past on linux, not to much, but something.
I've instaled Arch Linux ARM - Linux 3.19.0-1-ARCH #1 PREEMPT Wed Feb 11 17:51:40 MST 2015 armv5tejl GNU/Linux
I'm starting slow with just some bash scripts on gpio pins and thats ok.
Now I want to use pwm and acording to this website all the files are in the /sys/class/pwm:

http://www.armadeus.com/wiki/index.php?title=PWM



But mine is empty  :-\



Can somebody help me? I want to use pwm but I dont know how  :-\

Regards

lambda

Is the pwm-mxs kernel module loaded?

If it is: Is the pwm also enabled in devicetree?

HTH,
Harald

FET_Destroyer

Hi lambda,

How do I know if the pwm-mxs kernel is being loaded?
I've follow the instructions on the arch linux arm website to create an SD card.

Regards

lambda

lsmod should show you the loaded kernel modules on any linux system.

uname -a will tell you the version of your kernel

in /proc/device-tree/ you should see your loaded device tree data.

I don't now about arch linux - i run all my imx23 boards with OpenWRT.

HTH,
Harald

FET_Destroyer

No loaded pwm module  :(
Can somedoby help me to install it? Do I need to compile all the arch linux kernel and modules?


Regards

lambda

Well, first step then is to see if the module is available on your system.
Should be somewhere below /lib/modules/<kernelversion>/

If the module is there, then load it with insmod or modprobe ...

If the module is not there, you will need help from somebody familiar with
archlinux.

HTH,
Harald

swahren

March 24, 2015, 08:17:24 pm #6 Last Edit: March 24, 2015, 08:53:37 pm by swahren
Hi FET_Destroyer,

how are you connected to your board (UART, USB or WIFI)?

Since PWM0 and PWM1 are on the same pins as Debug UART this is a more difficult task than simple GPIO.

Stefan

Edit: Good news, i've look at the i.MX233 reference manual and it's look like that PWM2 is also available and don't have any conflicts (CON2 - pin 27).