On 20 June 2014 17:42, Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Thursday 19 June 2014 15:04:50 Ulf Hansson wrote: >> +Power sequence DT bindings >> + >> +Each power sequence method has a corresponding "power-method" property string. >> +This property shall be set in a subnode for a device. That subnode should also >> +describe resourses which are specific to that power method. >> + >> +Do note, power sequences as such isn't encoded through DT. Instead those are >> +implemented by each power method. >> + >> +Required subnode properties: >> +- power-method: should contain the string for the power method to bind. >> + >> + Supported power methods: None. >> + >> +Example: >> + >> +Note, the "clock" power method in this example isn't actually supported, but >> +used to visualize how a childnode could be described. > > I'm not too thrilled about adding another top-level concept for these. I agree, but when you collects the requirements from the discussions we have had around this topic - I don't think we can find another solution. But I might be wrong. > This seems to duplicate some things that pm-domains do, but does them > in a somewhata different way. Would it be possible to instead integrate > it into the pm-domain code? No, I don't think so. That main argument would be that runtime PM is not fine grained enough, but there are several other reasons. Please refer to previous discussions. > > I also agree with Olof that having a standalone child device node is > not the best representation. If you want to represent an SDIO device > device that has some references to clocks, regulators, etc, then put > that device into the tree and give it those properties. Could you elaborate on why? Where would a card (SDIO/SD/MMC) be better placed - unless as a child node under a mmc host device? > That would also let you worry about the sequencing in driver code rather > than trying to come up with a completely generic model for it. So in principle your are suggesting to "pre-probe" all discoverable devices/buses, not just for SDIO ( aka mmc subsystem). Will that even work for modules? Kind regards Uffe > > Arnd -- 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
