On Tuesday 08 December 2015 16:22:40 John Stultz wrote: > >> diff --git a/arch/arm/boot/dts/qcom-apq8064-nexus7-flo.dts b/arch/arm/boot/dts/qcom-apq8064-nexus7-flo.dts > >> index 5183d18..ee5dcb7 100644 > >> --- a/arch/arm/boot/dts/qcom-apq8064-nexus7-flo.dts > >> +++ b/arch/arm/boot/dts/qcom-apq8064-nexus7-flo.dts > >> @@ -282,6 +282,15 @@ > >> }; > >> }; > >> > >> + reboot_reason: reboot_reason@2a03f65c { > >> + compatible = "reboot_reason"; > >> + reg = <0x2A03F65C 0x4>; > >> + reason,none = <0x77665501>; > >> + reason,bootloader = <0x77665500>; > >> + reason,recovery = <0x77665502>; > >> + reason,oem = <0x6f656d00>; > >> + }; > >> + > > > > This address refers to IMEM, which is shared with a number of other > > uses. So I think we should have a simple-mfd (and syscon) with this > > within. > > Errr.. I'm going to have to read up there. I'm not super familiar with > any of those drivers, so I'll try to see how exactly they would map in > here. Is this an SRAM? We already have a generic SRAM binding, and I think this would fit in there. > > I like the fact that you don't hard code the magics in the > > implementation, as I've seen additions from multiple places - so perhaps > > it should be made even more flexible. > > > > OMAP seems to use strings here instead of magics, but the delivery > > mechanism looks to be the same. But I think of this as Qualcomm > > specific. > > Yea. This is good feedback. EFI bootloaders have their own > implementations as well. I suspect we'll need a few different driver > "types" to handle these differences, ie: value vs string. > > I'll maybe extend the compatible string to make it clear that this is > a "value" style, and we can extend it with a string type later if > folks care? If the two known implementations are already fundamentally different, there is a good chance that other vendors have found some more ways to do the same thing, so we might need to do this as a framework, or merge it into an existing framework. Maybe it can be done in the same driver that also handles rebooting the machine? Those are typically in drivers/power/reset or in drivers/watchdog/ for machines that use the watchdog as the only way to reboot the machine. We can have additional device specific properties along with the reboot method (e.g. a reference to the SRAM or some syscon node) and add common code in another file if we need it. > >> + /* initialize specified reasons from DT */ > >> + if (!of_property_read_u32(pdev->dev.of_node, "reason,none", &val)) > >> + reasons[NONE] = val; > >> + if (!of_property_read_u32(pdev->dev.of_node, "reason,bootloader", &val)) > >> + reasons[BOOTLOADER] = val; > >> + if (!of_property_read_u32(pdev->dev.of_node, "reason,recovery", &val)) > >> + reasons[RECOVERY] = val; > >> + if (!of_property_read_u32(pdev->dev.of_node, "reason,oem", &val)) > >> + reasons[OEM] = val; > > > > I would like for this to be less hard coded. > > Any tips here on how to do so? If we move this logic into the qcom reset driver in drivers/power/reset/msm-poweroff.c, we should be good. 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