Message-ID: <CY4PR03MB339970E6E74B0051427417A49B919@CY4PR03MB3399.namprd03.prod.outlook.com>
Date:   Mon, 8 Nov 2021 10:01:04 +0000
From:   "Miclaus, Antoniu" <Antoniu.Miclaus@...log.com>
To:     Jonathan Cameron <Jonathan.Cameron@...wei.com>
CC:     Jonathan Cameron <jic23@...nel.org>, Rob Herring <robh@...nel.org>,
        "linux-iio@...r.kernel.org" <linux-iio@...r.kernel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "Sa, Nuno" <Nuno.Sa@...log.com>
Subject: RE: [PATCH v3 2/2] dt-bindings: iio: frequency: add admv1013 doc

--
Antoniu Miclăuş

> -----Original Message-----
> From: Jonathan Cameron <Jonathan.Cameron@...wei.com>
> Sent: Friday, November 5, 2021 7:10 PM
> To: Miclaus, Antoniu <Antoniu.Miclaus@...log.com>
> Cc: Jonathan Cameron <jic23@...nel.org>; Rob Herring <robh@...nel.org>;
> linux-iio@...r.kernel.org; devicetree@...r.kernel.org; linux-
> kernel@...r.kernel.org; Sa, Nuno <Nuno.Sa@...log.com>
> Subject: Re: [PATCH v3 2/2] dt-bindings: iio: frequency: add admv1013 doc
> 
> [External]
> 
> On Fri, 5 Nov 2021 08:38:42 +0000
> "Miclaus, Antoniu" <Antoniu.Miclaus@...log.com> wrote:
> 
> > > -----Original Message-----
> > > From: Jonathan Cameron <jic23@...nel.org>
> > > Sent: Thursday, November 4, 2021 8:27 PM
> > > To: Miclaus, Antoniu <Antoniu.Miclaus@...log.com>
> > > Cc: Rob Herring <robh@...nel.org>; linux-iio@...r.kernel.org;
> > > devicetree@...r.kernel.org; linux-kernel@...r.kernel.org; Sa, Nuno
> > > <Nuno.Sa@...log.com>
> > > Subject: Re: [PATCH v3 2/2] dt-bindings: iio: frequency: add admv1013
> doc
> > >
> > > [External]
> > >
> > > On Wed, 3 Nov 2021 14:30:56 +0000
> > > "Miclaus, Antoniu" <Antoniu.Miclaus@...log.com> wrote:
> > >
> > > > Example:
> > > > In the setup that we tested the driver, we had a clock chip that was
> > > hardware-routed only to the positive side of the local oscillator input (LOP
> > > pin) from admv1013.
> > > >
> > > > Therefore, I think keeping the property in the DT might be useful.
> > >
> > > I think Rob's question was more general than that one property... See
> below.
> > > >
> > > > Regards,
> > > > --
> > > > Antoniu Miclăuş
> > > >
> > > > > -----Original Message-----
> > > > > From: Miclaus, Antoniu
> > > > > Sent: Wednesday, November 3, 2021 10:09 AM
> > > > > To: Rob Herring <robh@...nel.org>
> > > > > Cc: jic23@...nel.org; linux-iio@...r.kernel.org;
> > > devicetree@...r.kernel.org;
> > > > > linux-kernel@...r.kernel.org; Sa, Nuno <Nuno.Sa@...log.com>
> > > > > Subject: RE: [PATCH v3 2/2] dt-bindings: iio: frequency: add admv1013
> > > doc
> > > > >
> > > > > Hello Rob,
> > > > >
> > > > > These properties are fixed and available in the datasheet (binary
> format):
> > > > > https://www.analog.com/media/en/technical-documentation/data-
> > > > > sheets/ADMV1013.pdf
> > > > >
> > > > > Please see Page 37 of 39, Table 15, QUAD_SE_MODE.
> > > > >
> > > > > Regards,
> > > > > --
> > > > > Antoniu Miclăuş
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: Rob Herring <robh@...nel.org>
> > > > > > Sent: Tuesday, November 2, 2021 7:51 PM
> > > > > > To: Miclaus, Antoniu <Antoniu.Miclaus@...log.com>
> > > > > > Cc: jic23@...nel.org; linux-iio@...r.kernel.org;
> > > > > devicetree@...r.kernel.org;
> > > > > > linux-kernel@...r.kernel.org; Sa, Nuno <Nuno.Sa@...log.com>
> > > > > > Subject: Re: [PATCH v3 2/2] dt-bindings: iio: frequency: add
> admv1013
> > > doc
> > > > > >
> > > > > > [External]
> > > > > >
> > > > > > On Mon, Nov 01, 2021 at 12:04:20PM +0200, Antoniu Miclaus wrote:
> > > > > > > Add device tree bindings for the ADMV1013 Upconverter.
> > > > > > >
> > > > > > > Signed-off-by: Antoniu Miclaus <antoniu.miclaus@...log.com>
> > > > > > > ---
> > > > > > >  .../bindings/iio/frequency/adi,admv1013.yaml  | 119
> > > > > > ++++++++++++++++++
> > > > > > >  1 file changed, 119 insertions(+)
> > > > > > >  create mode 100644
> > > > > >
> Documentation/devicetree/bindings/iio/frequency/adi,admv1013.yaml
> > > > > > >
> > > > > > > diff --git
> > > > > >
> > >
> a/Documentation/devicetree/bindings/iio/frequency/adi,admv1013.yaml
> > > > > >
> > >
> b/Documentation/devicetree/bindings/iio/frequency/adi,admv1013.yaml
> > > > > > > new file mode 100644
> > > > > > > index 000000000000..47993253a586
> > > > > > > --- /dev/null
> > > > > > > +++
> > > > > >
> > >
> b/Documentation/devicetree/bindings/iio/frequency/adi,admv1013.yaml
> > > > > > > @@ -0,0 +1,119 @@
> > > > > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > > > > +%YAML 1.2
> > > > > > > +---
> > > > > > > +$id:
> > > > > >
> > > > >
> > >
> https://urldefense.com/v3/__http://devicetree.org/schemas/iio/frequency
> > > > > >
> > > > >
> > >
> /adi,admv1013.yaml*__;Iw!!A3Ni8CS0y2Y!uTDPalOgj6YS_vZ6bsDSbA_Qna6Q
> > > > > > OwMpoRxzo6nn06i5TNuGWZEk9PvtbC6SKQGXrugy$
> > > > > > > +$schema:
> > > https://urldefense.com/v3/__http://devicetree.org/meta-
> > > > > >
> > > > >
> > >
> schemas/core.yaml*__;Iw!!A3Ni8CS0y2Y!uTDPalOgj6YS_vZ6bsDSbA_Qna6Q
> > > > > > OwMpoRxzo6nn06i5TNuGWZEk9PvtbC6SKYugV1fM$
> > > > > > > +
> > > > > > > +title: ADMV1013 Microwave Upconverter
> > > > > > > +
> > > > > > > +maintainers:
> > > > > > > +  - Antoniu Miclaus <antoniu.miclaus@...log.com>
> > > > > > > +
> > > > > > > +description: |
> > > > > > > +   Wideband, microwave upconverter optimized for point to point
> > > > > > microwave
> > > > > > > +   radio designs operating in the 24 GHz to 44 GHz frequency
> range.
> > > > > > > +
> > > > > > > +   https://www.analog.com/en/products/admv1013.html
> > > > > > > +
> > > > > > > +properties:
> > > > > > > +  compatible:
> > > > > > > +    enum:
> > > > > > > +      - adi,admv1013
> > > > > > > +
> > > > > > > +  reg:
> > > > > > > +    maxItems: 1
> > > > > > > +
> > > > > > > +  spi-max-frequency:
> > > > > > > +    maximum: 1000000
> > > > > > > +
> > > > > > > +  clocks:
> > > > > > > +    description:
> > > > > > > +      Definition of the external clock.
> > > > > > > +    minItems: 1
> > > > > > > +
> > > > > > > +  clock-names:
> > > > > > > +    items:
> > > > > > > +      - const: lo_in
> > > > > > > +
> > > > > > > +  clock-output-names:
> > > > > > > +    maxItems: 1
> > > > > > > +
> > > > > > > +  vcm-supply:
> > > > > > > +    description:
> > > > > > > +      Analog voltage regulator.
> > > > > > > +
> > > > > > > +  adi,vga-powerdown:
> > > > > > > +    description:
> > > > > > > +      Power Down the Voltage Gain Amplifier Circuit available at
> > > > > > > +      BG_RBIAS2 pin.
> > > > > > > +    type: boolean
> > >
> > > What wiring would make it sensible to always have this powered down?
> > > If we can describe that rather than vga-powerdown then that is what
> should
> > > be in the binding.  If there isn't any wiring based justification and this
> > > is just turning off part of the device, then it should not be in the binding.
> > >
> > This part is similar to ADRF6780 that has also an Enable Register that can
> power down circuit blocks within the part:
> >
> https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/g
> it/jic23/iio.git/tree/drivers/iio/frequency/adrf6780.c?h=togreg__;!!A3Ni8CS0
> y2Y!sZfM9jaILdXhyFOXGx3KQHQOxNJaKopL7sEw2F-
> xzEWT0xHdoIW5sUEYE9ezdwHxPPWy$
> >
> 
> Hmm.  Guess we weren't super awake with that one :(
> 
> > I preferred to expose these properties in the device tree, rather than
> creating custom device attributes in the driver.
> >
> > But I guess these properties can be managed also only from debug fs.
> 
> The ideal situation is to control these based on what the device is being used
> for
> and not provide explicit control to userspace or via dt.
> 
> So if it doesn't make sense to power up a unit because it isn't wired to
> anything
> then express the wiring in DT.

All these powerdown properties have individual supply pins assigned (VCC_MIXER,
VCC_BG, VCC_QUAD... datasheet - page 8 of 39).
So I guess we can consider to enable/disable these blocks based on the wiring.

Looking forward to your feedback.

> 
> If it makes sense to power down a unit because it isn't being used currently
> due to what features are in use, then power it down automatically.  Runtime
> pm
> handles a lot of these cases by letting you do autopowerdown if not used
> after
> a certain period.  That way, we don't end up powering up and down rapidly
> but
> only do it if we have go reason to believe it is worth powering down.
> 
> Could we use either of these approaches here?
> 
> Jonathan
> >
> > I can adapt the code based on your decision. Looking forward to your
> feedback.
> > > > > > > +
> > > > > > > +  adi,mixer-powerdown:
> > > > > > > +    description:
> > > > > > > +      Power Down the Mixer Circuit. Enable to put the block in
> > > > > > > +      a power down state.
> > >
> > > Same for all these other power downs.
> > >
> > > > > > > +    type: boolean
> > > > > > > +
> > > > > > > +  adi,quad-powerdown:
> > > > > > > +    description:
> > > > > > > +      Power Down the Quadrupler. Enable to put the block in
> > > > > > > +      a power down state.
> > > > > > > +    type: boolean
> > > > > > > +
> > > > > > > +  adi,bg-powerdown:
> > > > > > > +    description:
> > > > > > > +      Power Down the Transmitter Band Gap. Enable to put the
> part in
> > > > > > > +      a power down state.
> > > > > > > +    type: boolean
> > > > > > > +
> > > > > > > +  adi,mixer-if-enable:
> > > > > > > +    description:
> > > > > > > +      Enable the Intermediate Frequency Mode. Either IF Mode or
> I/Q
> > > > > Mode
> > > > > > > +      can be enabled at a time.
> > > > > > > +    type: boolean
> > > > > > > +
> > > > > > > +  adi,detector-enable:
> > > > > > > +    description:
> > > > > > > +      Enable the Envelope Detector available at output pins
> VENV_P
> > > and
> > > > > > > +      VENV_N. Disable to reduce power consumption.
> > > > > > > +    type: boolean
> > > > > > > +
> > > > > > > +  adi,quad-se-mode:
> > > > > > > +    description:
> > > > > > > +      Switch the LO path from differential to single-ended
> operation.
> > > > > > > +      Set value 6 for Single-Ended Mode, Negative Side Disabled.
> > > > > > > +      Set value 9 for Single-Ended Mode, Positive Side Disabled.
> > > > > > > +      Set value 12 for Differential Mode.
> > > > > > > +    $ref: /schemas/types.yaml#/definitions/uint32
> > > > > > > +    enum: [6, 9, 12]
> > > > > >
> > > > > > All these vendor properties are fixed based on the board design or
> > > > > > something a user may want to change? The latter does not belong
> in
> > > DT.
> > > > > >
> > > > > > Rob
> >

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