How to change period of backlight pwm?

Technical Support
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1

Hi for all,
I would like to change period of backlight pwm.
In toradex website it was written that pwm 4 for responsible for this issue.

When i try to acces via sysfs path, the system says that there is no directory.

 PWM4	PWM4	/sys/class/backlight/backlight.17/	Used for backlight control

Also Can i change it in boot2qt dts file ?

&backlight { 	
brightness-levels = <0   45 63 88 119 158 203 255>; 	
default-brightness-level = <4>; 	
power-supply = <&reg_3v3_sw>; 	
pwms = <&pwm4 0 6666667 PWM_POLARITY_INVERTED>; 	
status = "okay"; };

how can i change the period of it ??
Thank you for your all support

2

Our touch panel in 4 brightness level gives us a black screen. We tought that we may change

  1. brightness-levels = < 0 45 63 88 119 158 203 255 >; into this

  2. brightness-levels = < 150 165 180 195 210 225 240 255 >;

but now we can not use touch panel. It does not recognize touch motion.

3

I solved it, the motion problem was related to another setting.

6666667 defines the period of the pwm.
pwms = <&pwm4 0 6666667 PWM_POLARITY_INVERTED>;

4

Hello @sevginurb ,

Thank you for your feedback. We are glad your problem is solved!

Best Regards,
Janani