On 15 January 2015 at 18:04, Mark Rutland <mark.rutland@xxxxxxx> wrote: > Hi, > > On Wed, Jan 14, 2015 at 01:02:10PM +0000, Ulf Hansson wrote: >> The need for a reset GPIO has several times been pointed out from >> earlier posted patchsets. Especially some WLAN chips which are >> attached to an SDIO interface may use a GPIO reset. >> >> In this first version, one reset pin is supported. We may want to >> extend the support to cover more pins, but let's leave that as a future >> change. The added DT binding for the reset GPIO can easily be extended >> to manage several pins. >> >> The reset GPIO is asserted at initialization and prior we start the >> power up procedure. It will then be de-asserted right after the power >> has been provided to the external chip/card, from the ->post_power_on() >> callback. > > This needs to be specified a little more explicitly in the binding > document below, as it forms part of the contract of the binding. > >> >> Note, the reset GPIO is optional. Thus we don't return an error even if >> we can't find a GPIO pin for the consumer. >> >> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> >> --- >> >> Changes in v2: >> - Adopted to the changed names of the pwrseq callbacks. >> >> --- >> .../devicetree/bindings/mmc/mmc,pwrseq-simple.txt | 5 +++ >> drivers/mmc/core/pwrseq_simple.c | 38 ++++++++++++++++++++++ >> 2 files changed, 43 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/mmc/mmc,pwrseq-simple.txt b/Documentation/devicetree/bindings/mmc/mmc,pwrseq-simple.txt >> index e1b7f9c..6fe0cd6 100644 >> --- a/Documentation/devicetree/bindings/mmc/mmc,pwrseq-simple.txt >> +++ b/Documentation/devicetree/bindings/mmc/mmc,pwrseq-simple.txt >> @@ -11,8 +11,13 @@ for several SOC designs. >> Required properties: >> - compatible : contains "mmc,pwrseq-simple". >> >> +Optional properties: >> +- reset-gpios : contains a list of GPIO specifiers, though currently only one >> + specifier is supported. > > The support is a Linux issue. If the binding is meant to describe a > list, mention that, and what the expected semantics are. > > Is it that difficult to have the driver iterate over the list now? I was trying to keep code simple, maybe too simple. :-) I will update the DT document according to your proposal and fix the code. Thanks for reviewing! Kind regards Uffe -- 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
