Re: [PATCH 1/4] arm64: dts: qcom: sc8280xp: rename i2c5 to i2c21

Shazad Hussain
2022-12-13T15:48:14Z

On 12/13/2022 9:09 PM, Johan Hovold wrote:
> On Tue, Dec 13, 2022 at 09:04:39PM +0530, Shazad Hussain wrote:
>>
>>
>> On 12/13/2022 8:58 PM, Johan Hovold wrote:
>>> On Tue, Dec 13, 2022 at 10:12:57AM -0500, Brian Masney wrote:
>>>> On Tue, Dec 13, 2022 at 03:54:05PM +0100, Johan Hovold wrote:
>>>>> Note that the node is labelled qup2_i2c5 and not qup_i2c5.
>>>>>
>>>>> That is, the QUP nodes are labelled using two indices, and specifically
>>>>>
>>>>> qup2_i2c5
>>>>>
>>>>> would be another name for
>>>>>
>>>>> qup_i2c21
>>>>>
>>>>> if we'd been using such a flat naming scheme (there are 8 engines per
>>>>> QUP).
>>>>>
>>>>> So there's nothing wrong with how these nodes are currently named, but
>>>>> mixing the two scheme as you are suggesting would not be correct.
>>>>
>>>> Hi Johan,
>>>>
>>>> What would I use for the name in the aliases section? Right now I have:
>>>>
>>>> aliases {
>>>> i2c18 = &qup2_i2c18;
>>>> }
>>>>
>>>> So qup2_i2c18 becomes qup2_i2c2. Would I use the flat naming scheme for
>>>> the alias like so?
>>>>
>>>> aliases {
>>>> i2c18 = &qup2_i2c2;
>>>> }
>>>
>>> Or perhaps the i2c controllers should use a zero-based index instead of
>>> being named after the serial engines (e.g. as we do for the console
>>> uart).
>>>
>>> How are they named in the schematics?
>>
>> We should use from 0 to N.
>
> With N being 23 after the number of serial engines, or the number of
> available i2c buses on a particular board minus one?
>

wrt to serial engine number starting from 0.

Shazad

> Johan