Hi Amit, amit shah wrote: > Wanted to now from which linux kernel version is the pwm based > buzzer (peizo) supported.
From the logfile: [...] 2011-11-11 Juergen Beisert <[email protected]> * Kernel 3.1: - add button 6 as a working GPIO key - add buzzer support [...] But: [...] 2012-12-16 Juergen Beisert <[email protected]> * Kernel 3.7: - Use most recent Linux release * Kernel 3.6: - lost buzzer fixed [...] Maybe some kernels between 3.1 and 3.6 still miss the buzzer again, due to changed PMW framework. > My app requires a variable freq sound o/p from (200-6000Hz) , can this be > supported out of the box or I need to write a driver? The PWM unit in the S3C2440 can do that. But the Samsung PWM driver is a *framework* only. You need some kind of frontend driver, which receives info from your userland application ("what should be done") and forwards it to the PWM framework to make the PWM unit what you expect. But you can find various examples how to do so (for example backlight drivers, LED drivers and the buzzer driver, which all uses the PWM framework to do the real job). Regards, Juergen -- Pengutronix e.K. | Juergen Beisert | Linux Solutions for Science and Industry | http://www.pengutronix.de/ |
