On Wed, Sep 4, 2013 at 1:29 PM, Alexandre Courbot <acourbot@xxxxxxxxxx> wrote: > +The GPIO framework has quite a bit of history behind it. Currently there exist > +two different (although very similar) ways of using GPIOs: > + > + - The legacy integer-based interface represents GPIOs as integers. This is > + the "historic" way of accessing GPIOs and it was done so because it makes > + GPIOs easy to represent and also allows for the compiler to statically know > + the GPIO number and use fast-paths on GPIOs for which performance matters. > + However, GPIOs can easily be forged this way, and the maximum number of > + GPIOs in the system must be known in advance. Functions of this interface > + are prefixed with "gpio_". > + > + - The new descriptor-based interface represents GPIOs as an opaque pointer. > + This ensures GPIOs are properly acquired before usage, and also does not > + presume anything about their underlying implementation. This interface > + provides get/put functions to acquire GPIOs according to their function for > + a particular device, similarly to e.g. the regulator framework. For these > + reasons, it is the preferred way to access GPIOs. Its functions are prefixed > + with "gpiod_". I would put all the new style gpiod_* based things on top of the file, and all the old stuff under a separate heading below DEPRECATED LEGACY INTERFACE so it's crystal clear that this is going away. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
