[PATCH 9/9] usb: {ohci,ehci}-platform: Use new OF big-endian helper function

Kevin Cernekee cernekee at gmail.com
Wed Nov 26 08:07:43 PST 2014


On Wed, Nov 26, 2014 at 7:14 AM, Alan Stern <stern at rowland.harvard.edu> wrote:
>> diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt
>> index 43c1a4e..9505c31 100644
>> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt
>> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt
>> @@ -12,6 +12,8 @@ Optional properties:
>>   - big-endian-regs : boolean, set this for hcds with big-endian registers
>>   - big-endian-desc : boolean, set this for hcds with big-endian descriptors
>>   - big-endian : boolean, for hcds with big-endian-regs + big-endian-desc
>> + - native-endian : boolean, enables big-endian-regs + big-endian-desc
>> +   iff the kernel was compiled for big endian
>
> Is this really a property of the hardware?  It appears to depend on the
> kernel configuration.  As such, is it appropriate for DT?

Yes, the peripheral registers automatically adjust their endianness to
match the CPU.  So if the CPU is running an LE kernel, the peripheral
needs to be accessed in LE mode; if the CPU is running a BE kernel,
the peripheral needs to be accessed in BE mode.



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