How to end call via adb in android 2.2.1? Im creating small call center like system based on pyadb.

I was developing for my phone which has custom SlimKat ROM - kitkat based.
To call i do :adb shell am start -a android.intent.action.CALL -d tel:xxxxxxxxx

To end the call i do input keyevent KEYCODE_ENDCALL
and it works like a charm on my phone.

But now my boss want's to use old htc wildfire (buzz) with android 2.2.1
On this phone adb input keyevent KEYCODE_ENDCALL gives me '[1] Killed ...`- error. 
I tried to use keycode number instead of KEYCODE_ENDCALL, like this:

adb shell input keyevent 6-

this is not giving error but does not have any effect on the phone.

Same for KEYCODE_MUTE.
Curiously KEYCODE_CALL(7) is working as expected.

How can i make it work? Can i change adb commands in anyway? Or maybe installing CyanogenMod(7- I think is the newest for this phone) will help?
Or is this lost fight and i need a newer phone for this?
Found that and it works for making and ending calls. Still looking for a way to mute Microphone.