On Mon, Jan 20, 2014 at 10:58 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Monday 20 January 2014, Olof Johansson wrote: >> >> +Card power and reset control: >> +The following properties can be specified for cases where the MMC >> +peripheral needs additional reset, regulator and clock lines. It is for >> +example common for WiFi/BT adapters to have these separate from the main >> +MMC bus: >> + - card-reset-gpios: Specify GPIOs for card reset (reset active low) >> + - card-external-vcc-supply: Regulator to drive (independent) card VCC >> + - clock with name "card_ext_clock": External clock provided to the card > > I wonder whether the reset line should use the generic reset controller binding > rather than the gpio binding. There has been a recent discussion about a > gpio-reset driver, which should generalize this at the reset level, and > it would make it possible to use reset controllers that are not gpio driven. > In general, any gpio can be used as a reset, but not every reset line can > be a gpio. I don't know whether anyone would use an internal reset-controller > for an external SDIO chip though, so maybe your approach is sufficient. I'd expect most usage of this to be through gpios, since we're talking about external independent modules here. I would prefer not to bring in the reset controller stuff here -- it just adds another layer of abstraction that seems unnecessary. I would prefer if the reset framework was contained to only be the on-chip SoC IP block resets, etc, as originally intended. -Olof -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
