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 :)
Best regards,
Yoshihiro Shimoda
