Re: [PATCH v2 1/2] Documentation: tpm: add the IBM Virtual TPM device tree binding documentation

[Nayna <nayna-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>]

On 10/09/2016 02:41 AM, Rob Herring wrote:
> On Wed, Sep 28, 2016 at 04:30:40AM -0400, Nayna Jain wrote:
>> Virtual TPM, which is being used on IBM POWER7+ and POWER8 systems running
>> POWERVM, is currently supported by tpm device driver but lacks the
>> documentation. This patch adds the missing documentation for the existing
>> support.
>>
>> Suggested-by: Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
>> Signed-off-by: Nayna Jain <nayna-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
>> ---
>> Changelog v2:
>>
>> - New Patch
>>
>>   .../devicetree/bindings/security/tpm/ibmvtpm.txt   | 41 ++++++++++++++++++++++
>>   1 file changed, 41 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/security/tpm/ibmvtpm.txt
>>
>> diff --git a/Documentation/devicetree/bindings/security/tpm/ibmvtpm.txt b/Documentation/devicetree/bindings/security/tpm/ibmvtpm.txt
>> new file mode 100644
>> index 0000000..d89f999
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/security/tpm/ibmvtpm.txt
>> @@ -0,0 +1,41 @@
>> +* Device Tree Bindings for IBM Virtual Trusted Platform Module(vtpm)
>> +
>> +Required properties:
>> +
>> +- compatible            : property name that conveys the platform architecture
>> +                          identifiers, as 'IBM,vtpm'
>
> You use IBM here, but...
>
>> +- device_type           : specifies type of virtual device
>> +- interrupts            : property specifying the interrupt source number and
>> +                          sense code associated with this virtual I/O Adapters
>> +- ibm,my-drc-index      : integer index for the connector between the device
>
> use ibm here. These should be the same unless there's some history I'm
> not aware of.

This is how the property was defined when the change was submitted to 
the PAPR. It was most likely an oversight that the IBM was not changed 
to ibm to be consistent with other property definitions.

>
>> +                          and its parent - present only if Dynamic
>> +                          Reconfiguration(DR) Connector is enabled
>> +- ibm,#dma-address-cells: specifies the number of cells that are used to
>> +                          encode the physical address field of dma-window
>> +                          properties
>> +- ibm,#dma-size-cells   : specifies the number of cells that are used to
>> +                          encode the size field of dma-window properties
>> +- ibm,my-dma-window     : specifies DMA window associated with this virtual
>> +                          IOA
>
> Are these "standard" IBM properties? Does dma-ranges not work for you?


Yes, these are the standard properties as defined in the PAPR.  Again 
the "ibm" prefix indicates that they are specific to IBM system 
implementation. They have been in existence for many years.


Thanks & Regards,
    - Nayna

>
>> +- ibm,loc-code          : specifies the unique and persistent location code
>> +                          associated with this virtual I/O Adapters
>> +- linux,sml-base        : 64-bit base address of the reserved memory allocated
>> +                          for the firmware event log
>> +- linux,sml-size        : size of the memory allocated for the firmware event log
>> +
>> +Example (IBM Virtual Trusted Platform Module)
>> +---------------------------------------------
>> +
>> +                vtpm@30000003 {
>> +                        ibm,#dma-size-cells = <0x2>;
>> +                        compatible = "IBM,vtpm";
>> +                        device_type = "IBM,vtpm";
>> +                        ibm,my-drc-index = <0x30000003>;
>> +                        ibm,#dma-address-cells = <0x2>;
>> +                        linux,sml-base = <0xc60e 0x0>;
>> +                        interrupts = <0xa0003 0x0>;
>> +                        ibm,my-dma-window = <0x10000003 0x0 0x0 0x0 0x10000000>;
>> +                        ibm,loc-code = "U8286.41A.10082DV-V3-C3";
>> +                        reg = <0x30000003>;
>> +                        linux,sml-size = <0xbce10200>;
>> +                };
>> --
>> 2.5.0
>>
>


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