Re: [PATCH v3 2/2] dt-bindings: net: bluetooth: Add device tree bindings for QTI chip wcn3998

From: Harish Bandi
Date: Wed Mar 27 2019 - 06:24:09 EST

Hi Matthias,

On 2019-03-27 05:24, Matthias Kaehlcke wrote:
On Mon, Mar 25, 2019 at 05:00:31PM +0530, c-hbandi@xxxxxxxxxxxxxx wrote:
Hi Matthias,

On 2019-03-15 00:26, Matthias Kaehlcke wrote:
> Hi Harish,
>
> On Wed, Mar 13, 2019 at 12:00:06PM +0530, c-hbandi@xxxxxxxxxxxxxx wrote:
> > Hi Matthias,
> >
> >
> > On 2019-03-12 22:29, Matthias Kaehlcke wrote:
> > > +DT folks
> > >
> > > Please add them in future versions (script/scripts/get_maintainer.pl
> > > <patches> should have listed them)
> >
> > [Harish] -- Will add them in new version of patches.
> > >
> > > On Tue, Mar 12, 2019 at 05:52:59PM +0530, Harish Bandi wrote:
> > > > This patch enables regulators for the Qualcomm Bluetooth wcn3998
> > > > controller.
> > >
> > > No, it doesn't.
> > >
> > > The next version should probably say something like "Add compatible
> > > string for the Qualcomm WCN3998 Bluetooth controller.
> > >
> > [Harish] -- From new patch onwards will add all patch
> > version changes and add proper description.
> >
> > > Is there any particular reason why QCA drivers folks use 'wcn' instead
> > > of 'WCN'? The QCA documentations calls it WCN399x, so I'd suggest to
> > > consistently use the uppercase name in comments and documentation (and
> > > log messages?).
> > >
> > [Harish] -- I think in DT we need to have small case like wcn,
>
> agreed
>
> > i think that is the reason it started using in code, comments and dt
> > documentation.
>
> AFAIK there are no hard rules for everything, my suggestion would be:
>
> - use WCN399x
> - for general comments/documentation
> - commit messages
> - in DT context wcn3998-n seems ok
> - use wcn399x
> - for function and variable names
> - for compatible strings
>
> For logging: whatever, just be consistent.

[Harish] --For Commit messages and all will try to follow change it new
patch

>
> > > > Signed-off-by: Harish Bandi <c-hbandi@xxxxxxxxxxxxxx>
> > > > ---
> > > > changes in v3:
> > > > - updated to latest code base.
> > >
> > > This comment is useless, please describe what changed wrt the previous
> > > version.
> > [Harish] -- added details in v2, and v3 uploaded just to rebase on
> > tip of
> > bluetooth-next
> > for better understanding of code in review. From new patch onwards
> > will add
> > all patch
> > version changes and add proper description.
> > >
> > > > ---
> > > > .../devicetree/bindings/net/qualcomm-bluetooth.txt | 15
> > > > +++++++++++++++
> > > > 1 file changed, 15 insertions(+)
> > > >
> > > > diff --git
> > > > a/Documentation/devicetree/bindings/net/qualcomm-bluetooth.txt
> > > > b/Documentation/devicetree/bindings/net/qualcomm-bluetooth.txt
> > > > index 824c0e2..1221535 100644
> > > > --- a/Documentation/devicetree/bindings/net/qualcomm-bluetooth.txt
> > > > +++ b/Documentation/devicetree/bindings/net/qualcomm-bluetooth.txt
> > > > @@ -53,3 +53,18 @@ serial@898000 {
> > > > max-speed = <3200000>;
> > > > };
> > > > };
> > > > +
> > > > +&blsp1_uart3 {
> > > > + pinctrl-names = "default";
> > > > + pinctrl-0 = <&blsp1_uart3_default>;
> > > > + status = "okay";
> > > > +
> > > > + bluetooth: wcn3998-bt {
> > > > + compatible = "qcom,wcn3998-bt";
> > > > + vddio-supply = <&vreg_l6_1p8>;
> > > > + vddxo-supply = <&vreg_l5_1p8>;
> > > > + vddrf-supply = <&vreg_s5_1p35>;
> > > > + vddch0-supply = <&vdd_ch0_3p3>;
> > > > + max-speed = <3200000>;
> > > > + };
> > > > +};
> > > > \ No newline at end of file
> > >
> > > I think the example isn't really needed since it's essentially the
> > > same as the one for 'qcom,wcn3990-bt'.
> > >
> > > But the important part is missing: add the new compatible string under
> > > ÂRequired propertiesÂ. You also want to update the documentation that
> > > mentiones 'qcom,wcn3990-bt' to 'qcom,wcn399x-bt' (assuming for now
> > > that other possible WCN399x chips would be similar).
> > >
> > [Harish] -- Will check the DT properties, documentation and update
> > accordingly in new patch.
> >
> > > You mentioned in an earlier version of the series that there are
> > > multiple WCN3998 variants with different requirements for
> > > voltage/current. This seems to suggests that multiple compatible
> > > strings are needed to distinguish between them.
> > >
> > [Harish] -- for now we want to add WCN3998 support only, What i mean
> > to say
> > in my earlier
> > explanation that. WCN3990 is base variant and on top of that we have
> > variants like WCN3990,
> > WCN3998 and WCN3998-0,WCN3998-1 like that..
> > So I think wcn399x would make sense for this series.
>
> If the variants have relevant differences between them (like different
> regulator requirements) I think you want unique names, rather than
> 'wcn399x' (I was referring to comments/documentation with this
> string).
>
> If there are variants wouldn't your first 'wcn3998' already be a
> 'wcn3998-n'? If 'wcn3998' without suffix is used I think it needs to
> be valid for all 'wcn3998-n' variants (it might be less
> power-efficient though than using the variant specific compatible
> string), otherwise things get confusing (a 'wcn3998-2' isn't a
> 'wcn3998'?)
>


[Harish] -- for now WCN3990 and WCN3998 only, also wcn3998-2 and wcn3998
are same.
So for now we are going to have only WCN3990 and WCN3998 for DT.

Since you brought up the different power requirements initially:

are your reasonably sure that future wcn3998-3, wcn3998-4, ... can
operate with the generic wcn3998 power settings?

[Harish] - yes with power settings of wcn3998, wcn3998-3 and wcn3998-4 ... also will work.