On Sun, Jan 19, 2014 at 07:56:53PM -0800, Olof Johansson wrote: > This patch enables support for power-on sequencing of SDIO peripherals through DT. > > In general, it's quite common that wifi modules and other similar > peripherals have several signals in addition to the SDIO interface that > needs wiggling before the module will power on. It's common to have a > reference clock, one or several power rails and one or several lines > for reset/enable type functions. > > The binding as written today introduces a number of reset gpios, > a regulator and a clock specifier. The code will handle up to 2 gpio > reset lines, but it's trivial to increase to more than that if needed > at some point. > > Implementation-wise, the MMC core has been changed to handle this during > host power up, before the host interface is powered on. I have not yet > implemented the power-down side, I wanted people to have a chance for > reporting back w.r.t. issues (or comments on the bindings) first. > > I have not tested the regulator portion, since the system and module > I'm working on doesn't need one (Samsung Chromebook with Marvell > 8797-based wifi). Testing of those portions (and reporting back) would > be appreciated. > > Signed-off-by: Olof Johansson <olof@xxxxxxxxx> > --- > Documentation/devicetree/bindings/mmc/mmc.txt | 11 +++++++ > drivers/mmc/core/core.c | 42 +++++++++++++++++++++++++ > drivers/mmc/core/host.c | 30 +++++++++++++++++- > include/linux/mmc/host.h | 5 +++ > 4 files changed, 87 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt > index 458b57f..962e0ee 100644 > --- a/Documentation/devicetree/bindings/mmc/mmc.txt > +++ b/Documentation/devicetree/bindings/mmc/mmc.txt > @@ -5,6 +5,8 @@ these definitions. > Interpreted by the OF core: > - reg: Registers location and length. > - interrupts: Interrupts used by the MMC controller. > +- clocks: Clocks needed for the host controller, if any. > +- clock-names: Goes with clocks above. > > Card detection: > If no property below is supplied, host native card detect is used. > @@ -30,6 +32,15 @@ Optional properties: > - cap-sdio-irq: enable SDIO IRQ signalling on this interface > - full-pwr-cycle: full power cycle of the card is supported > > +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) We have GPIO_ACTIVE_LOW/HIGH. No need to hardcode this. 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-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
