On Mon, Dec 09, 2013 at 07:04:12PM +0800, randy wrote:
[...]
> Actually, I don't know whether the pwm works or not. In dmesg, I saw:
> [  853.690000] samsung-pwm 139d0000.pwm: tried to request PWM channel
> 0 without output
> [  876.930000] samsung-pwm 139d0000.pwm: tried to request PWM channel
> 0 without output
> [  879.615000] samsung-pwm 139d0000.pwm: tried to request PWM channel
> 1 without output
> 
> in my dts, I only add
> ================================
> pwm@139D0000 {
> 	status = "okay";
> };
> ================================
> is it enough to make pwm work, if the driver in kernel has been correct.

It seems like you're missing the samsung,pwm-outputs property (see
Documentation/devicetree/bindings/pwm/pwm-samsung.txt).

Thierry