On Friday 13 November 2009, Grant Likely wrote: > Right now, I don't > see a fundamental difference is between GPIO and PWM pin management. > It is essentially the same problem, and in many cases PWM pins can > also be used as GPIOs. Pin management for a given SoC is going to be relevant to setting every signal, no matter what peripheral it's associated with. The same argument applies to an MDIO bus, I2C, 1-wire, and more. And I don't buy it in those cases either. > I think the question should be flipped around; > rather than asking for a compelling reason for them to be merged; I > want to know the compelling reason to keep them separate. What is the > fundamental difference that keeps them apart? PWM is about periodic signal generation without CPU intervention. GPIO is about explicit CPU management/interrogation of single signals. > What I would like to see is the PWM functions added to the GPIO API. No. If you want a pin mux interface, come up with one of them. It shouldn't be a PWM interface, a GPIO interface, an I2C interface, a SPI interface, an MDIO interface, a 1-wire interface ... or any of dozens of other things. It'd be purely for pinmux. -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
