fd_buzzer = open("/dev/pwm",0); error on qtopia

unknown
hi all

in C++ example, code { fd_buzzer = open("/dev/pwm",0); } works fine; but in
Qtopia2.2.0  code { fd_buzzer = open("/dev/pwm",0); } produce the following
error:

Hello2440 was terminated due to application error (11).


where is the problem?

by the way, where can I find source code of pwm_testing application in
mini2440 ?

regards