On 01/30/15 13:48, Kumar Gala wrote:
> On Jan 30, 2015, at 3:37 PM, Stephen Boyd <sb...@codeaurora.org> wrote:
>
>> On 01/30/15 08:32, Kumar Gala wrote:
>>> On Jan 30, 2015, at 12:25 AM, Andy Gross <agr...@codeaurora.org> wrote:
>>>
>>>> Required properties if child node exists:
>>>> - #address-cells: Must be 1
>>>> - #size-cells: Must be 1
>>>> - ranges: Must be present
>>>>
>>>> +Note: Each GSBI should have an alias correctly numbered in "aliases" node.
>>>> +
>>>> Properties for children:
>>>>
>>>> A GSBI controller node can contain 0 or more child nodes representing
>>>> serial
>>>> @@ -37,6 +41,10 @@ Example for APQ8064:
>>>>
>>>> #include <dt-bindings/soc/qcom,gsbi.h>
>>>>
>>>> + aliases {
>>>> + gsbi4 = <&gsbi4>;
>>>> + };
>>> You appear to be using the alias name to determine a index number for the
>>> gsbi, if that is the case, than you should probably just add a cell-index
>>> node to the gsbi’s for this purpose.
>>>
>> I thought cell-index was "deprecated" and referred more to things like
>> enumerating all the devices on a bus by assigning them a unique ID.
>> Aliases, on the other hand, allow us to enumerate a subset of devices
>> that share the same bus with other devices of different types. For
>> example, how would I know that a device is gsbi1 vs serial1 if they both
>> used cell-index and they both had the same parent node?
> I think the problem was cell-index was never well understood and abused. For
> the example you are giving you wouldn’t use cell-index because you are
> talking about things that would have different compatibles. For what it
> appears we really are enumerating the GSBI hardware to match some programming
> interface convention. If that is the case than I think cell-index is proper.
Can you please explain when cell-index should be used and when aliases
should be used? I'm confused because I recall this message from Rob
Herring[1] where it's indicated that cell-index is pretty much
deprecated. I'm also interested to find out what cell means in
cell-index. Does it have any relation to *-cells properties?
[1] https://lkml.org/lkml/2012/11/10/102
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