Re: [PATCH v3 3/3] arm64: dts: sdm845: Add serial console support

From: Rajendra Nayak
Date: Thu Feb 15 2018 - 00:13:21 EST




On 02/15/2018 12:41 AM, Bjorn Andersson wrote:
> [..]
>>> +
>>> + qup_1: geni-se@ac0000 {
>> Color me confused. So you're saying here that this is "qup_1".
>> ...but above you turn the pinmux for pins "GPIO4" and "GPIO5" to
>> "qup9", right? So UART2 is on "qup 1" and "qup 9"?
>>
>> ...OK, so I stared at manuals a bunch more, and _maybe_ I get it.
>> Maybe there are 3 "QUP v3 modules" each of which handles up to 8
>> "QUP"s. So QUP 9 is on "QUP module 1", is that right? If everyone
>> understands this already and it's just me that's confused then I guess
>> you can just ignore this comment. However, if you can think of any
>> better alias than "qup_1" that makes this less confusing then that
>> would make me extra happy. Like maybe "qupv3_id_1" to match the
>> manual?
> This is indeed a source of confusion, in particular since there tend to
> be different numbering depending on what part of the puzzle you look at.
> But you're right that each QUP has a number of engines, each one being a
> UART/I2C/SPI controller.
>
> I don't see a reason for labeling this particular node though, aliases
> references individual engines, not the wrapper.

makes sense, I'll just drop the label.


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