On Wed, Feb 15, 2017 at 02:21:55AM +0000, Yoshihiro Shimoda wrote: > Hi, > > I would like to get a related device pointer on usb EHCI drivers (or USB framework) > because related device (e.g. OHCI or UHCI, called "companion controllers") has to > finish resuming. I discussed this topic with Alan: > http://marc.info/?t=148653514200001&r=1&w=2 > > In PCI bus, USB framework already has such a feature in drivers/usb/core/hcd-pci.c. > However, in platform devices, we don't have it for now. So, I would like to add it. > > Then, I have 2 ideas to get the related device pointer: > > A) We add a new property "companion" as usb-generic.txt and EHCI node(s) have > such a property to bind a companion controller. > B) We assume EHCI controller binds a companion controller if some resources > (irq or clock) are the same and it has a compatible strings as "generic-[uo]hci" > for instance. > > My environment is R-Car H3, and it has 3 EHCI and 3 OHCI controllers. > For example (I only wrote channel 0 of EHCI and OHCI): > ehci0: usb@ee080100 { > compatible = "generic-ehci"; > reg = <0 0xee080100 0 0x100>; > interrupts = <GIC_SPI 108 IRQ_TYPE_LEVEL_HIGH>; > clocks = <&cpg CPG_MOD 703>; > phys = <&usb2_phy0>; > phy-names = "usb"; > power-domains = <&sysc R8A7795_PD_ALWAYS_ON>; > status = "disabled"; > }; > > ohci0: usb@ee080000 { > compatible = "generic-ohci"; > reg = <0 0xee080000 0 0x100>; > interrupts = <GIC_SPI 108 IRQ_TYPE_LEVEL_HIGH>; > clocks = <&cpg CPG_MOD 703>; > phys = <&usb2_phy0>; > phy-names = "usb"; > power-domains = <&sysc R8A7795_PD_ALWAYS_ON>; > status = "disabled"; > }; > > If my idea A), ehci0 will have companion = <&ohci>; > If my idea B), no need to add any property. > > What do you think? > Anyway, I will start to study DT programming :) > >From my point, idea A is better. It seems you have similar idea when you tried Dual-role framework before. [1] [1] https://patchwork.kernel.org/patch/9169745/ -- Best Regards, Peter Chen -- 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
