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Subject: Re: [PATCH v8 10/14] usb: otg: add hcd companion support
To: Rob Herring <robh@kernel.org>
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From: Roger Quadros <rogerq@ti.com>
Message-ID: <573980EA.10901@ti.com>
Date: Mon, 16 May 2016 11:12:26 +0300
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On 13/05/16 21:13, Rob Herring wrote:
> On Fri, May 13, 2016 at 5:03 AM, Roger Quadros <rogerq@ti.com> wrote:
>> From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
>>
>> Since some host controller (e.g. EHCI) needs a companion host controller
>> (e.g. OHCI), this patch adds such a configuration to use it in the OTG
>> core.
>>
>> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>> Acked-by: Peter Chen <peter.chen@nxp.com>
>> ---
>>  Documentation/devicetree/bindings/usb/generic.txt |  3 +++
>>  drivers/usb/common/usb-otg.c                      | 32 ++++++++++++++++-------
>>  include/linux/usb/otg.h                           |  7 ++++-
>>  3 files changed, 32 insertions(+), 10 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/usb/generic.txt b/Documentation/devicetree/bindings/usb/generic.txt
>> index f6866c1..1db1c33 100644
>> --- a/Documentation/devicetree/bindings/usb/generic.txt
>> +++ b/Documentation/devicetree/bindings/usb/generic.txt
>> @@ -27,6 +27,9 @@ Optional properties:
>>   - otg-controller: phandle to otg controller. Host or gadget controllers can
>>                         contain this property to link it to a particular OTG
>>                         controller.
>> + - hcd-needs-companion: must be present if otg controller is dealing with
>> +                       EHCI host controller that needs a companion OHCI host
>> +                       controller.
> 
> I thought the conclusion was this is not needed?

This is still needed to differentiate between primary+shared HCD case vs
primary + primary-companion HCD case.

> 
> One thing that is not clear here is otg-controller is a host or device
> property while hcd-needs-companion is an OTG controller property.
> These lists should be separated.

Agreed. I'll fix that up.

cheers,
-roger