Re: [PATCHv2 03/16] Documentation: dt: add OMAP iommu bindings

[Suman Anna <s-anna@ti.com>]

Mark, Kumar, Rob,

> On 02/13/2014 07:15 PM, Suman Anna wrote:
>> From: Florian Vaussard <florian.vaussard@epfl.ch>
>>
>> This patch adds the iommu bindings for all OMAP2+ SoCs. Apart from
>> the standard bindings used by OMAP peripherals, this patch uses a
>> 'dma-window' (already used by Tegra SMMU) and adds two OMAP custom
>> bindings - 'ti,#tlb-entries' and 'ti,iommu-bus-err-back'.
>>
>> Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
>> [s-anna@ti.com: split bindings document, add dra7 and bus error back]
>> Signed-off-by: Suman Anna <s-anna@ti.com>
>> ---
>>   .../devicetree/bindings/iommu/ti,omap-iommu.txt    | 28 ++++++++++++++++++++++
>>   1 file changed, 28 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/iommu/ti,omap-iommu.txt
>>
>> diff --git a/Documentation/devicetree/bindings/iommu/ti,omap-iommu.txt b/Documentation/devicetree/bindings/iommu/ti,omap-iommu.txt
>> new file mode 100644
>> index 0000000..116492d
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iommu/ti,omap-iommu.txt
>> @@ -0,0 +1,28 @@
>> +OMAP2+ IOMMU
>> +
>> +Required properties:
>> +- compatible : Should be one of,
>> +		"ti,omap2-iommu" for OMAP2/OMAP3 IOMMU instances
>> +		"ti,omap4-iommu" for OMAP4/OMAP5 IOMMU instances
>> +		"ti,dra7-iommu" for DRA7xx IOMMU instances
>> +- ti,hwmods  : Name of the hwmod associated with the IOMMU instance
>> +- reg        : Address space for the configuration registers
>> +- interrupts : Interrupt specifier for the IOMMU instance
>> +- dma-window : IOVA start address and length
>> +
>> +Optional properties:
>> +- ti,#tlb-entries : Number of entries in the translation look-aside buffer.
>> +                    Should be either 8 or 32 (default: 32)
>> +- ti,iommu-bus-err-back : Indicates the IOMMU instance supports throwing
>> +		          back a bus error response on MMU faults.
>> +
>> +Example:
>> +	/* OMAP3 ISP MMU */
>> +	mmu_isp: mmu@480bd400 {
>> +		compatible = "ti,omap2-iommu";
>> +		reg = <0x480bd400 0x80>;
>> +		interrupts = <24>;
>> +		ti,hwmods = "mmu_isp";
>> +		ti,#tlb-entries = <8>;
>> +		dma-window = <0 0xfffff000>;
>> +	};
>>
>
> Any comments on this binding?

Can one of you look through this binding and ack/suggest changes?
As I mentioned in the cover letter, the optional properties usually 
apply only to specific subsystems, so do let me know if this should be 
handled using compatible string per subsystem per SoC rather than per SoC.

regards
Suman