On Mon, Nov 19, 2012 at 11:40:30AM +0100, Linus Walleij wrote: > On Mon, Nov 19, 2012 at 9:52 AM, Peter Ujfalusi <peter.ujfalusi@xxxxxx> wrote: > > > I was actually tempted to remove the whole LED (PWM) thing from the > > gpio-twl4030 driver. It was a big surprise to me to see something like this in > > there. > > It looks wrong. In theory I think this should be ripped out and moved to > drivers/leds/leds-twl4030.c. But that would only be in case it was *always* > exclusively used for a LED and as you say: > > > It turns out that on BeagleBoard the USB host enable signal is connected to > > LEDA (PWMA) of twl4030... It is an enable signal. Seriously. So what we do > > here is either configure the PWMs as full on, or turn it off. > > Sounds like some hardware engineer has been having fun or was > just out of GPIOs to use... So this LED PWM is also used as a > GPIO. > > I think this part of the driver should be moved to > drivers/pwm/pwm-twl4030.c and modeled as a PWM. If some > platform need to use the PWM as if it was a GPIO then that's just a > special usecase. (Setting duty cycles to something like > INT_MAX and just switching polarity to toggle it...) > > If it needs to be used by a LED there needs to be some generic > LED type just using a standard pwm_request() to get some > specific PWM, such as leds/leds-pwm.c or so. This way the > PWM can be used for LEDs if need be or other things... Either I'm misinterpreting you or you didn't have a look in the tree. Actually drivers/leds/leds-pwm.c already exists. > > Sounds correct, Sascha? Yes, the twl4030 pwm should go to drivers/pwm/pwm-twl4030.c. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
