[PATCH 0/2] iio: dac: ad5791: Add support for controlling RBUF via devicetree

[PATCH 0/2] iio: dac: ad5791: Add support for controlling RBUF via devicetree

[Nuno Sa via B4 Relay]

Simple series to add support for an external amplifier to be connected
in again of two configuration.

---
Michael Hennerich (2):
      dt-bindings: adi,ad5791.yaml: Add support for controlling RBUF
      iio: dac: ad5791: Add support for controlling RBUF via devicetree

 Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml | 5 +++++
 drivers/iio/dac/ad5791.c                                  | 9 ++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

Thanks!
- Nuno Sá

[PATCH 1/2] dt-bindings: adi,ad5791.yaml: Add support for controlling RBUF

[Nuno Sa via B4 Relay]

From: Michael Hennerich <michael.hennerich@analog.com>

This patch adds support for an external amplifier to be connected in a
gain of two configuration.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Nuno Sa <nuno.sa@analog.com>
---
 Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
index 3a84739736f6..c81285d84db7 100644
--- a/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
+++ b/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
@@ -26,6 +26,11 @@ properties:
   vdd-supply: true
   vss-supply: true
 
+  adi,rbuf-gain2-en:
+    description: Specify to allow an external amplifier to be connected in a
+      gain of two configuration.
+    type: boolean
+
 required:
   - compatible
   - reg

-- 
2.43.0

Re: [PATCH 1/2] dt-bindings: adi,ad5791.yaml: Add support for controlling RBUF

[Krzysztof Kozlowski]

On 27/11/2023 16:55, Nuno Sa via B4 Relay wrote:
> From: Michael Hennerich <michael.hennerich@analog.com>
> 

Subject: drop ".yaml"

> This patch adds support for an external amplifier to be connected in a

Please do not use "This commit/patch", but imperative mood. See longer
explanation here:
https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95

> gain of two configuration.
> 
> Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
> Signed-off-by: Nuno Sa <nuno.sa@analog.com>
> ---
>  Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
> index 3a84739736f6..c81285d84db7 100644
> --- a/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
> +++ b/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
> @@ -26,6 +26,11 @@ properties:
>    vdd-supply: true
>    vss-supply: true
>  
> +  adi,rbuf-gain2-en:
> +    description: Specify to allow an external amplifier to be connected in a
> +      gain of two configuration.

I don't understand this. Without this property external amplifier is not
allowed to be connected? This sounds like some policy, but should rather
focus on hardware.

Best regards,
Krzysztof

Re: [PATCH 1/2] dt-bindings: adi,ad5791.yaml: Add support for controlling RBUF

[Nuno Sá]

On Tue, 2023-11-28 at 10:33 +0100, Krzysztof Kozlowski wrote:
> On 27/11/2023 16:55, Nuno Sa via B4 Relay wrote:
> > From: Michael Hennerich <michael.hennerich@analog.com>
> > 
> 
> Subject: drop ".yaml"

Will do...

> 
> > This patch adds support for an external amplifier to be connected in a
> 
> Please do not use "This commit/patch", but imperative mood. See longer
> explanation here:
> https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95

ack...

> 
> > gain of two configuration.
> > 
> > Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
> > Signed-off-by: Nuno Sa <nuno.sa@analog.com>
> > ---
> >  Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml | 5 +++++
> >  1 file changed, 5 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
> > b/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
> > index 3a84739736f6..c81285d84db7 100644
> > --- a/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
> > +++ b/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
> > @@ -26,6 +26,11 @@ properties:
> >    vdd-supply: true
> >    vss-supply: true
> >  
> > +  adi,rbuf-gain2-en:
> > +    description: Specify to allow an external amplifier to be connected in
> > a
> > +      gain of two configuration.
> 
> I don't understand this. Without this property external amplifier is not
> allowed to be connected? This sounds like some policy, but should rather
> focus on hardware.
> 

Well, this really translates in a different configuration in the device. If this
is set then the device is configured to allow an external amplifier to be
connected in a gain of two configuration which depends on the HW setup you want
the chip to be.

The description already states pretty much what the datasheet says. So while I
understand it's a fair question from you (you don't have the time to check all
datasheets for reviews you do), I'm not sure there's much more to add into the
description of the property.

- Nuno Sá

Re: [PATCH 1/2] dt-bindings: adi,ad5791.yaml: Add support for controlling RBUF

[Krzysztof Kozlowski]

On 28/11/2023 11:11, Nuno Sá wrote:
> On Tue, 2023-11-28 at 10:33 +0100, Krzysztof Kozlowski wrote:
>> On 27/11/2023 16:55, Nuno Sa via B4 Relay wrote:
>>> From: Michael Hennerich <michael.hennerich@analog.com>
>>>
>>
>> Subject: drop ".yaml"
> 
> Will do...
> 
>>
>>> This patch adds support for an external amplifier to be connected in a
>>
>> Please do not use "This commit/patch", but imperative mood. See longer
>> explanation here:
>> https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95
> 
> ack...
> 
>>
>>> gain of two configuration.
>>>
>>> Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
>>> Signed-off-by: Nuno Sa <nuno.sa@analog.com>
>>> ---
>>>  Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml | 5 +++++
>>>  1 file changed, 5 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
>>> b/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
>>> index 3a84739736f6..c81285d84db7 100644
>>> --- a/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
>>> +++ b/Documentation/devicetree/bindings/iio/dac/adi,ad5791.yaml
>>> @@ -26,6 +26,11 @@ properties:
>>>    vdd-supply: true
>>>    vss-supply: true
>>>  
>>> +  adi,rbuf-gain2-en:
>>> +    description: Specify to allow an external amplifier to be connected in
>>> a
>>> +      gain of two configuration.
>>
>> I don't understand this. Without this property external amplifier is not
>> allowed to be connected? This sounds like some policy, but should rather
>> focus on hardware.
>>
> 
> Well, this really translates in a different configuration in the device. If this
> is set then the device is configured to allow an external amplifier to be
> connected in a gain of two configuration which depends on the HW setup you want
> the chip to be.
> 
> The description already states pretty much what the datasheet says. So while I
> understand it's a fair question from you (you don't have the time to check all
> datasheets for reviews you do), I'm not sure there's much more to add into the
> description of the property.
> 

OK, it's fine there. With earlier fixes:

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

[PATCH 2/2] iio: dac: ad5791: Add support for controlling RBUF via devicetree

[Nuno Sa via B4 Relay]

From: Michael Hennerich <michael.hennerich@analog.com>

This patch adds support for an external amplifier to be connected in a
gain of two configuration.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Nuno Sa <nuno.sa@analog.com>
---
 drivers/iio/dac/ad5791.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/dac/ad5791.c b/drivers/iio/dac/ad5791.c
index a4167454da81..75b549827e15 100644
--- a/drivers/iio/dac/ad5791.c
+++ b/drivers/iio/dac/ad5791.c
@@ -345,6 +345,7 @@ static int ad5791_probe(struct spi_device *spi)
 	struct iio_dev *indio_dev;
 	struct ad5791_state *st;
 	int ret, pos_voltage_uv = 0, neg_voltage_uv = 0;
+	bool use_rbuf_gain2;
 
 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 	if (!indio_dev)
@@ -379,6 +380,12 @@ static int ad5791_probe(struct spi_device *spi)
 	st->pwr_down = true;
 	st->spi = spi;
 
+	if (pdata)
+		use_rbuf_gain2 = pdata->use_rbuf_gain2;
+	else
+		use_rbuf_gain2 = device_property_read_bool(&spi->dev,
+							   "adi,rbuf-gain2-en");
+
 	if (!IS_ERR(st->reg_vss) && !IS_ERR(st->reg_vdd)) {
 		st->vref_mv = (pos_voltage_uv + neg_voltage_uv) / 1000;
 		st->vref_neg_mv = neg_voltage_uv / 1000;
@@ -398,7 +405,7 @@ static int ad5791_probe(struct spi_device *spi)
 
 
 	st->ctrl = AD5761_CTRL_LINCOMP(st->chip_info->get_lin_comp(st->vref_mv))
-		  | ((pdata && pdata->use_rbuf_gain2) ? 0 : AD5791_CTRL_RBUF) |
+		  | (use_rbuf_gain2 ? 0 : AD5791_CTRL_RBUF) |
 		  AD5791_CTRL_BIN2SC;
 
 	ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl |

-- 
2.43.0