Hi Rob and all, On Fri, 2019-03-15 at 00:44 +0800, Rob Herring wrote: > On Thu, Mar 14, 2019 at 3:46 AM Marc Gonzalez <marc.w.gonzalez@xxxxxxx> wrote: > > > > On 13/03/2019 20:48, Rob Herring wrote: > > > > Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt mentions: > > - <name>-fixed-regulator : boolean property specifying that <name>-supply is a fixed regulator. > > > > > There are no users of that property in tree and doesn't look like > > > adding it was ever reviewed. We have standard ways to handle this and > > > don't need a custom property. > > > > FWIW, it seems to come from downstream: > > The question would be is downstream compliant with the upstream > binding. If so, then we shouldn't really break things as that's just > out of tree which is fine. > > Or we just need a better explanation of why it is needed. MMC has some > properties related to card voltages for example. Maybe the need is > similar. > For short-term, could this patch series be merged without "vcc" related property defined in dt-bindings (like PATCH V5 does)? Or using "vcc-supply" along with "vcc-fixed-regulator" with a detailed explanation can be accepted? ufs-mediatek can work fine without "vcc" related property but with a limitation that driver cannot control "vcc" power which is enabled by-default on MediaTek chipsets. For long-term, it seems to me that "<name>-fixed-regulator" can be removed from both dt-bindings and UFS driver without impact, even for downstream usage found by Marc. If "<name>-fixed-regulator" property is defined in device tree, such regulator will skip "current limit" assignment from "<name>-max-microamp" property, and voltage range assignment from "vcc-supply-lp8" property (for vcc, vccq, and vccq2 only). If driver can handle above both cases correctly, "<name>-fixed-regulator" can be removed. In MediaTek chipsets, "vcc-supply" can ignore above two properties. However if "vcc-fixed-regulator" is not added, driver will get fail during device tree probing due to undefined "vcc-max-microamp". If our target is removing "<name>-fixed-regulator", we could try to fix and resolve above all. And if we do not merge "vcc" related property this time, after that we can add "vcc-supply" back to dt-bindings to provide vcc control capability in ufs-mediatek driver. Would you please provide any suggestions? > Rob
