2011/1/31 Sascha Hauer [off-list ref]:

On Sun, Jan 30, 2011 at 11:49:32AM +0800, arden jay wrote:

quoted

Sorry, I'm confused about this.
If it is for backlight control, why it don't go through led_class?

PWMs are not limited to backlight. As Jean pointed out they can be used
for fans (or more generally motors) aswell. Have a look at
drivers/leds/leds-pwm.c, it is a user of this pwm API.

Low-frequency PWM is used for vibrators of the type found in
silent mode cellphones, to mention another use case.

Yours,
Linus Walleij