Add documentation of device tree bindings to support
sigma delta modulator backend in IIO framework.
Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com>
---
.../iio/adc/sd-modulator-backend.yaml | 39 +++++++++++++++++++
1 file changed, 39 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/sd-modulator-backend.yaml
diff --git a/Documentation/devicetree/bindings/iio/adc/sd-modulator-backend.yaml b/Documentation/devicetree/bindings/iio/adc/sd-modulator-backend.yaml
new file mode 100644
index 000000000000..3299db71f79d
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/sd-modulator-backend.yaml
@@ -0,0 +1,39 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/sd-modulator-backend.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sigma delta modulator backend
+
+maintainers:
+ - Olivier Moysan <olivier.moysan@foss.st.com>
+
+properties:
+ compatible:
+ enum:
+ - ti,ads1201
+
+ '#io-backend-cells':
+ const: 0
+
+ reg:
+ maxItems: 1
+
+ vref-supply:
+ description: Phandle to the vref input analog reference voltage.
+
+required:
+ - compatible
+ - '#io-backend-cells'
+
+additionalProperties: false
+
+examples:
+ - |
+ ads1201: adc {
+ compatible = "ti,ads1201";
+ #io-backend-cells = <0>;
+ };
+
+...
--
2.25.1On Tue, Jun 25, 2024 at 05:07:13PM +0200, Olivier Moysan wrote: > Add documentation of device tree bindings to support > sigma delta modulator backend in IIO framework. > > Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com> I don't review bindings for a job, I can only reliably get to look at my mail queue in the evenings, please give me a chance to reply to you before you submit a new version. > +$id: http://devicetree.org/schemas/iio/adc/sd-modulator-backend.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Sigma delta modulator backend Same comments about filename and title apply here as the previous version. "TI $foo Sigma Delta Modulator" and drop the reference to back ends or the pretence of being generic. Thanks, Conor.
Hi Conor, On 6/25/24 17:34, Conor Dooley wrote: > On Tue, Jun 25, 2024 at 05:07:13PM +0200, Olivier Moysan wrote: >> Add documentation of device tree bindings to support >> sigma delta modulator backend in IIO framework. >> >> Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com> > > I don't review bindings for a job, I can only reliably get to look at > my mail queue in the evenings, please give me a chance to reply to you > before you submit a new version. > Sorry, the short review delay. >> +$id: http://devicetree.org/schemas/iio/adc/sd-modulator-backend.yaml# >> +$schema: http://devicetree.org/meta-schemas/core.yaml# >> + >> +title: Sigma delta modulator backend > > Same comments about filename and title apply here as the previous > version. "TI $foo Sigma Delta Modulator" and drop the reference to back > ends or the pretence of being generic. > The logic here is the same as for the former sigma delta modulator driver. (see discussion [1]) I mean introducing a generic and minimalist driver to support sd modulators, but not dedicated to a specific modulator. The ads1201 is chosen as a basic modulator here. But it is rather an arbitrary choice. I agree "backend" reference is not really relevant here. I have to think about a way to manage the coexistence of this sigma delta modulator driver with its former version. [1] https://lore.kernel.org/all/6943aaf5-b580-0fd1-7a2e-b99f7a266388@st.com/ BRs Olivier > Thanks, > Conor.
On Wed, Jun 26, 2024 at 06:40:58PM +0200, Olivier MOYSAN wrote: > Hi Conor, > > On 6/25/24 17:34, Conor Dooley wrote: > > On Tue, Jun 25, 2024 at 05:07:13PM +0200, Olivier Moysan wrote: > > > Add documentation of device tree bindings to support > > > sigma delta modulator backend in IIO framework. > > > > > > Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com> > > > > I don't review bindings for a job, I can only reliably get to look at > > my mail queue in the evenings, please give me a chance to reply to you > > before you submit a new version. > > > > Sorry, the short review delay. > > > > +$id: http://devicetree.org/schemas/iio/adc/sd-modulator-backend.yaml# > > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > > + > > > +title: Sigma delta modulator backend > > > > Same comments about filename and title apply here as the previous > > version. "TI $foo Sigma Delta Modulator" and drop the reference to back > > ends or the pretence of being generic. > > > > The logic here is the same as for the former sigma delta modulator driver. > (see discussion [1]) > I mean introducing a generic and minimalist driver to support sd modulators, > but not dedicated to a specific modulator. The ads1201 is chosen as a basic > modulator here. But it is rather an arbitrary choice. > > I agree "backend" reference is not really relevant here. I have to think > about a way to manage the coexistence of this sigma delta modulator driver > with its former version. To be blunt, I don't care about drivers! Well I do, but not in this particular context. You can absolutely have a driver that supports multiple backends or sigma delta modulators, but right now we are talking about a binding and this binding supports exactly one sigma delta modulator - and with an explicit compatible. In that context, presenting the binding as generic makes little sense. > [1] https://lore.kernel.org/all/6943aaf5-b580-0fd1-7a2e-b99f7a266388@st.com/ Looking at this though, I question the binding more... The programming model of the device is identical as a backend or otherwise, so it shouldn't be getting a new compatible. Isn't this actually as simple as adding #io-backend-cells to the existing binding and using that to determine whether the device is being used as a backend or in isolation? Thanks, Conor.
Hi Conor, On 6/27/24 18:13, Conor Dooley wrote: > On Wed, Jun 26, 2024 at 06:40:58PM +0200, Olivier MOYSAN wrote: >> Hi Conor, >> >> On 6/25/24 17:34, Conor Dooley wrote: >>> On Tue, Jun 25, 2024 at 05:07:13PM +0200, Olivier Moysan wrote: >>>> Add documentation of device tree bindings to support >>>> sigma delta modulator backend in IIO framework. >>>> >>>> Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com> >>> >>> I don't review bindings for a job, I can only reliably get to look at >>> my mail queue in the evenings, please give me a chance to reply to you >>> before you submit a new version. >>> >> >> Sorry, the short review delay. >> >>>> +$id: http://devicetree.org/schemas/iio/adc/sd-modulator-backend.yaml# >>>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>>> + >>>> +title: Sigma delta modulator backend >>> >>> Same comments about filename and title apply here as the previous >>> version. "TI $foo Sigma Delta Modulator" and drop the reference to back >>> ends or the pretence of being generic. >>> >> >> The logic here is the same as for the former sigma delta modulator driver. >> (see discussion [1]) >> I mean introducing a generic and minimalist driver to support sd modulators, >> but not dedicated to a specific modulator. The ads1201 is chosen as a basic >> modulator here. But it is rather an arbitrary choice. >> >> I agree "backend" reference is not really relevant here. I have to think >> about a way to manage the coexistence of this sigma delta modulator driver >> with its former version. > > To be blunt, I don't care about drivers! Well I do, but not in this > particular context. You can absolutely have a driver that supports > multiple backends or sigma delta modulators, but right now we are > talking about a binding and this binding supports exactly one sigma > delta modulator - and with an explicit compatible. In that context, > presenting the binding as generic makes little sense. > >> [1] https://lore.kernel.org/all/6943aaf5-b580-0fd1-7a2e-b99f7a266388@st.com/ > > Looking at this though, I question the binding more... The programming > model of the device is identical as a backend or otherwise, so it > shouldn't be getting a new compatible. Isn't this actually as simple as > adding #io-backend-cells to the existing binding and using that to > determine whether the device is being used as a backend or in isolation? > For sure. I came to the same conclusion. My first idea was to isolate the deprecated binding. However, I agree that the best approach is to adapt the existing binding. I prepared a v3 like this. BRs Olivier > Thanks, > Conor.
Hi Conor, On 6/27/24 18:13, Conor Dooley wrote: > On Wed, Jun 26, 2024 at 06:40:58PM +0200, Olivier MOYSAN wrote: >> Hi Conor, >> >> On 6/25/24 17:34, Conor Dooley wrote: >>> On Tue, Jun 25, 2024 at 05:07:13PM +0200, Olivier Moysan wrote: >>>> Add documentation of device tree bindings to support >>>> sigma delta modulator backend in IIO framework. >>>> >>>> Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com> >>> >>> I don't review bindings for a job, I can only reliably get to look at >>> my mail queue in the evenings, please give me a chance to reply to you >>> before you submit a new version. >>> >> >> Sorry, the short review delay. >> >>>> +$id: http://devicetree.org/schemas/iio/adc/sd-modulator-backend.yaml# >>>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>>> + >>>> +title: Sigma delta modulator backend >>> >>> Same comments about filename and title apply here as the previous >>> version. "TI $foo Sigma Delta Modulator" and drop the reference to back >>> ends or the pretence of being generic. >>> >> >> The logic here is the same as for the former sigma delta modulator driver. >> (see discussion [1]) >> I mean introducing a generic and minimalist driver to support sd modulators, >> but not dedicated to a specific modulator. The ads1201 is chosen as a basic >> modulator here. But it is rather an arbitrary choice. >> >> I agree "backend" reference is not really relevant here. I have to think >> about a way to manage the coexistence of this sigma delta modulator driver >> with its former version. > > To be blunt, I don't care about drivers! Well I do, but not in this > particular context. You can absolutely have a driver that supports > multiple backends or sigma delta modulators, but right now we are > talking about a binding and this binding supports exactly one sigma > delta modulator - and with an explicit compatible. In that context, > presenting the binding as generic makes little sense. > >> [1] https://lore.kernel.org/all/6943aaf5-b580-0fd1-7a2e-b99f7a266388@st.com/ > > Looking at this though, I question the binding more... The programming > model of the device is identical as a backend or otherwise, so it > shouldn't be getting a new compatible. Isn't this actually as simple as > adding #io-backend-cells to the existing binding and using that to > determine whether the device is being used as a backend or in isolation? > For sure. I came to the same conclusion. My first idea was to isolate the deprecated binding. But I agree that the best approach is to adapt the existing binding. I prepared a v3 like this. BRs Olivier > Thanks, > Conor.
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