[PATCH 0/2] iio: core: Add optional symbolic label to device attributes

[PATCH 0/2] iio: core: Add optional symbolic label to device attributes

[Phil Reid]

If a label is defined in the device tree for this device add that
to the device specific attributes. This is useful for userspace to
be able to identify an individual device when multiple identical
chips are present in the system.

Similar to leds, display labels etc.

Phil Reid (2):
  dt-binding: iio: Add optional label property
  iio: core: Add optional symbolic label to device attributes

 Documentation/devicetree/bindings/iio/iio-bindings.txt |  5 +++++
 drivers/iio/industrialio-core.c                        | 17 +++++++++++++++++
 include/linux/iio/iio.h                                |  1 +
 3 files changed, 23 insertions(+)

-- 
1.8.3.1

[PATCH 1/2] dt-binding: iio: Add optional label property

[Phil Reid]

This optional property defines a symbolic name for the device.

Signed-off-by: Phil Reid <preid@electromag.com.au>
---
 Documentation/devicetree/bindings/iio/iio-bindings.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/iio-bindings.txt b/Documentation/devicetree/bindings/iio/iio-bindings.txt
index 68d6f8ce063b..ffeae5aad8b5 100644
--- a/Documentation/devicetree/bindings/iio/iio-bindings.txt
+++ b/Documentation/devicetree/bindings/iio/iio-bindings.txt
@@ -18,12 +18,17 @@ Required properties:
 		   with a single IIO output and 1 for nodes with multiple
 		   IIO outputs.
 
+Optional properties:
+label:		   A symbolic name for the device.
+
+
 Example for a simple configuration with no trigger:
 
 	adc: voltage-sensor@35 {
 		compatible = "maxim,max1139";
 		reg = <0x35>;
 		#io-channel-cells = <1>;
+		label = "adc_voltage_sensor";
 	};
 
 Example for a configuration with trigger:
-- 
1.8.3.1

Re: [PATCH 1/2] dt-binding: iio: Add optional label property

[Michal Simek]

On 27. 08. 19 5:35, Phil Reid wrote:
> This optional property defines a symbolic name for the device.
> 
> Signed-off-by: Phil Reid <preid@electromag.com.au>
> ---
>  Documentation/devicetree/bindings/iio/iio-bindings.txt | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/iio-bindings.txt b/Documentation/devicetree/bindings/iio/iio-bindings.txt
> index 68d6f8ce063b..ffeae5aad8b5 100644
> --- a/Documentation/devicetree/bindings/iio/iio-bindings.txt
> +++ b/Documentation/devicetree/bindings/iio/iio-bindings.txt
> @@ -18,12 +18,17 @@ Required properties:
>  		   with a single IIO output and 1 for nodes with multiple
>  		   IIO outputs.
>  
> +Optional properties:
> +label:		   A symbolic name for the device.
> +
> +
>  Example for a simple configuration with no trigger:
>  
>  	adc: voltage-sensor@35 {
>  		compatible = "maxim,max1139";
>  		reg = <0x35>;
>  		#io-channel-cells = <1>;
> +		label = "adc_voltage_sensor";
>  	};
>  
>  Example for a configuration with trigger:
> 

Suggested-by: Michal Simek <michal.simek@xilinx.com>

Thanks,
Michal

Re: [PATCH 1/2] dt-binding: iio: Add optional label property

[Michal Simek]

On 27. 08. 19 5:35, Phil Reid wrote:
> This optional property defines a symbolic name for the device.
> 
> Signed-off-by: Phil Reid <preid@electromag.com.au>
> ---
>  Documentation/devicetree/bindings/iio/iio-bindings.txt | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/iio-bindings.txt b/Documentation/devicetree/bindings/iio/iio-bindings.txt
> index 68d6f8ce063b..ffeae5aad8b5 100644
> --- a/Documentation/devicetree/bindings/iio/iio-bindings.txt
> +++ b/Documentation/devicetree/bindings/iio/iio-bindings.txt
> @@ -18,12 +18,17 @@ Required properties:
>  		   with a single IIO output and 1 for nodes with multiple
>  		   IIO outputs.
>  
> +Optional properties:
> +label:		   A symbolic name for the device.
> +
> +
>  Example for a simple configuration with no trigger:
>  
>  	adc: voltage-sensor@35 {
>  		compatible = "maxim,max1139";
>  		reg = <0x35>;
>  		#io-channel-cells = <1>;
> +		label = "adc_voltage_sensor";
>  	};
>  
>  Example for a configuration with trigger:
> 

Just for the record. This patch has been created based on initial
discussion about label property. And Rob had not problem with using
label in connection to ina226. https://lkml.org/lkml/2019/8/27/1213

Thanks,
Michal

Re: [PATCH 1/2] dt-binding: iio: Add optional label property

[Rob Herring]

On Wed, Aug 28, 2019 at 08:09:19AM +0200, Michal Simek wrote:
> On 27. 08. 19 5:35, Phil Reid wrote:
> > This optional property defines a symbolic name for the device.
> > 
> > Signed-off-by: Phil Reid <preid@electromag.com.au>
> > ---
> >  Documentation/devicetree/bindings/iio/iio-bindings.txt | 5 +++++
> >  1 file changed, 5 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/iio/iio-bindings.txt b/Documentation/devicetree/bindings/iio/iio-bindings.txt
> > index 68d6f8ce063b..ffeae5aad8b5 100644
> > --- a/Documentation/devicetree/bindings/iio/iio-bindings.txt
> > +++ b/Documentation/devicetree/bindings/iio/iio-bindings.txt
> > @@ -18,12 +18,17 @@ Required properties:
> >  		   with a single IIO output and 1 for nodes with multiple
> >  		   IIO outputs.
> >  
> > +Optional properties:
> > +label:		   A symbolic name for the device.
> > +
> > +
> >  Example for a simple configuration with no trigger:
> >  
> >  	adc: voltage-sensor@35 {
> >  		compatible = "maxim,max1139";
> >  		reg = <0x35>;
> >  		#io-channel-cells = <1>;
> > +		label = "adc_voltage_sensor";
> >  	};
> >  
> >  Example for a configuration with trigger:
> > 
> 
> Just for the record. This patch has been created based on initial
> discussion about label property. And Rob had not problem with using
> label in connection to ina226. https://lkml.org/lkml/2019/8/27/1213

I didn't, but based on the name here I'm less convinced. 'label' is 
supposed to be for needing to distinguish between more than 1 of 
something. A name like 'adc_voltage_sensor' doesn't really.

Rob

Re: [PATCH 1/2] dt-binding: iio: Add optional label property

[Phil Reid]

On 30/08/2019 07:02, Rob Herring wrote:
> On Wed, Aug 28, 2019 at 08:09:19AM +0200, Michal Simek wrote:
>> On 27. 08. 19 5:35, Phil Reid wrote:
>>> This optional property defines a symbolic name for the device.
>>>
>>> Signed-off-by: Phil Reid <preid@electromag.com.au>
>>> ---
>>>   Documentation/devicetree/bindings/iio/iio-bindings.txt | 5 +++++
>>>   1 file changed, 5 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/iio/iio-bindings.txt b/Documentation/devicetree/bindings/iio/iio-bindings.txt
>>> index 68d6f8ce063b..ffeae5aad8b5 100644
>>> --- a/Documentation/devicetree/bindings/iio/iio-bindings.txt
>>> +++ b/Documentation/devicetree/bindings/iio/iio-bindings.txt
>>> @@ -18,12 +18,17 @@ Required properties:
>>>   		   with a single IIO output and 1 for nodes with multiple
>>>   		   IIO outputs.
>>>   
>>> +Optional properties:
>>> +label:		   A symbolic name for the device.
>>> +
>>> +
>>>   Example for a simple configuration with no trigger:
>>>   
>>>   	adc: voltage-sensor@35 {
>>>   		compatible = "maxim,max1139";
>>>   		reg = <0x35>;
>>>   		#io-channel-cells = <1>;
>>> +		label = "adc_voltage_sensor";
>>>   	};
>>>   
>>>   Example for a configuration with trigger:
>>>
>>
>> Just for the record. This patch has been created based on initial
>> discussion about label property. And Rob had not problem with using
>> label in connection to ina226. https://lkml.org/lkml/2019/8/27/1213
> 
> I didn't, but based on the name here I'm less convinced. 'label' is
> supposed to be for needing to distinguish between more than 1 of
> something. A name like 'adc_voltage_sensor' doesn't really.
> 
> Rob
> 
> 

That's the problem we're try to solve. Having multiple devices and try to
determine which device is which.
eg: Mutliple adc's.
For example I have the same dac chip on multiple boards that do different
things, it's difficult to id them.

so label examples could be:
label = "current_control_group1";
label = "voltage_control_group1";

Are you totally against this or is it a problem with me not being clear
with the problem and the wording of the commit message or the example?




-- 
Regards
Phil Reid

Re: [PATCH 1/2] dt-binding: iio: Add optional label property

[Rob Herring]

On Thu, Aug 29, 2019 at 8:01 PM Phil Reid <preid@electromag.com.au> wrote:
>
> On 30/08/2019 07:02, Rob Herring wrote:
> > On Wed, Aug 28, 2019 at 08:09:19AM +0200, Michal Simek wrote:
> >> On 27. 08. 19 5:35, Phil Reid wrote:
> >>> This optional property defines a symbolic name for the device.
> >>>
> >>> Signed-off-by: Phil Reid <preid@electromag.com.au>
> >>> ---
> >>>   Documentation/devicetree/bindings/iio/iio-bindings.txt | 5 +++++
> >>>   1 file changed, 5 insertions(+)
> >>>
> >>> diff --git a/Documentation/devicetree/bindings/iio/iio-bindings.txt b/Documentation/devicetree/bindings/iio/iio-bindings.txt
> >>> index 68d6f8ce063b..ffeae5aad8b5 100644
> >>> --- a/Documentation/devicetree/bindings/iio/iio-bindings.txt
> >>> +++ b/Documentation/devicetree/bindings/iio/iio-bindings.txt
> >>> @@ -18,12 +18,17 @@ Required properties:
> >>>                with a single IIO output and 1 for nodes with multiple
> >>>                IIO outputs.
> >>>
> >>> +Optional properties:
> >>> +label:                A symbolic name for the device.
> >>> +
> >>> +
> >>>   Example for a simple configuration with no trigger:
> >>>
> >>>     adc: voltage-sensor@35 {
> >>>             compatible = "maxim,max1139";
> >>>             reg = <0x35>;
> >>>             #io-channel-cells = <1>;
> >>> +           label = "adc_voltage_sensor";
> >>>     };
> >>>
> >>>   Example for a configuration with trigger:
> >>>
> >>
> >> Just for the record. This patch has been created based on initial
> >> discussion about label property. And Rob had not problem with using
> >> label in connection to ina226. https://lkml.org/lkml/2019/8/27/1213
> >
> > I didn't, but based on the name here I'm less convinced. 'label' is
> > supposed to be for needing to distinguish between more than 1 of
> > something. A name like 'adc_voltage_sensor' doesn't really.
> >
> > Rob
> >
> >
>
> That's the problem we're try to solve. Having multiple devices and try to
> determine which device is which.
> eg: Mutliple adc's.
> For example I have the same dac chip on multiple boards that do different
> things, it's difficult to id them.
>
> so label examples could be:
> label = "current_control_group1";
> label = "voltage_control_group1";
>
> Are you totally against this or is it a problem with me not being clear
> with the problem and the wording of the commit message or the example?

It's just the example is less than ideal. But it's just an example, so:

Reviewed-by: Rob Herring <robh@kernel.org>

Feel free to update the example if you respin.

Rob

Re: [PATCH 1/2] dt-binding: iio: Add optional label property

[Phil Reid]

On 30/08/2019 20:34, Rob Herring wrote:
> On Thu, Aug 29, 2019 at 8:01 PM Phil Reid <preid@electromag.com.au> wrote:
>>
>> On 30/08/2019 07:02, Rob Herring wrote:
>>> On Wed, Aug 28, 2019 at 08:09:19AM +0200, Michal Simek wrote:
>>>> On 27. 08. 19 5:35, Phil Reid wrote:
>>>>> This optional property defines a symbolic name for the device.
>>>>>
>>>>> Signed-off-by: Phil Reid <preid@electromag.com.au>
>>>>> ---
>>>>>    Documentation/devicetree/bindings/iio/iio-bindings.txt | 5 +++++
>>>>>    1 file changed, 5 insertions(+)
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/iio/iio-bindings.txt b/Documentation/devicetree/bindings/iio/iio-bindings.txt
>>>>> index 68d6f8ce063b..ffeae5aad8b5 100644
>>>>> --- a/Documentation/devicetree/bindings/iio/iio-bindings.txt
>>>>> +++ b/Documentation/devicetree/bindings/iio/iio-bindings.txt
>>>>> @@ -18,12 +18,17 @@ Required properties:
>>>>>                 with a single IIO output and 1 for nodes with multiple
>>>>>                 IIO outputs.
>>>>>
>>>>> +Optional properties:
>>>>> +label:                A symbolic name for the device.
>>>>> +
>>>>> +
>>>>>    Example for a simple configuration with no trigger:
>>>>>
>>>>>      adc: voltage-sensor@35 {
>>>>>              compatible = "maxim,max1139";
>>>>>              reg = <0x35>;
>>>>>              #io-channel-cells = <1>;
>>>>> +           label = "adc_voltage_sensor";
>>>>>      };
>>>>>
>>>>>    Example for a configuration with trigger:
>>>>>
>>>>
>>>> Just for the record. This patch has been created based on initial
>>>> discussion about label property. And Rob had not problem with using
>>>> label in connection to ina226. https://lkml.org/lkml/2019/8/27/1213
>>>
>>> I didn't, but based on the name here I'm less convinced. 'label' is
>>> supposed to be for needing to distinguish between more than 1 of
>>> something. A name like 'adc_voltage_sensor' doesn't really.
>>>
>>> Rob
>>>
>>>
>>
>> That's the problem we're try to solve. Having multiple devices and try to
>> determine which device is which.
>> eg: Mutliple adc's.
>> For example I have the same dac chip on multiple boards that do different
>> things, it's difficult to id them.
>>
>> so label examples could be:
>> label = "current_control_group1";
>> label = "voltage_control_group1";
>>
>> Are you totally against this or is it a problem with me not being clear
>> with the problem and the wording of the commit message or the example?
> 
> It's just the example is less than ideal. But it's just an example, so:
> 
> Reviewed-by: Rob Herring <robh@kernel.org>
> 
> Feel free to update the example if you respin.
> 
Thanks Rob,

I'll update the example if the series gets a respin.



-- 
Regards
Phil Reid

Re: [PATCH 1/2] dt-binding: iio: Add optional label property

[Jonathan Cameron]

On Sat, 31 Aug 2019 18:19:53 +0800
Phil Reid <preid@electromag.com.au> wrote:

> On 30/08/2019 20:34, Rob Herring wrote:
> > On Thu, Aug 29, 2019 at 8:01 PM Phil Reid <preid@electromag.com.au> wrote:  
> >>
> >> On 30/08/2019 07:02, Rob Herring wrote:  
> >>> On Wed, Aug 28, 2019 at 08:09:19AM +0200, Michal Simek wrote:  
> >>>> On 27. 08. 19 5:35, Phil Reid wrote:  
> >>>>> This optional property defines a symbolic name for the device.
> >>>>>
> >>>>> Signed-off-by: Phil Reid <preid@electromag.com.au>
> >>>>> ---
> >>>>>    Documentation/devicetree/bindings/iio/iio-bindings.txt | 5 +++++
> >>>>>    1 file changed, 5 insertions(+)
> >>>>>
> >>>>> diff --git a/Documentation/devicetree/bindings/iio/iio-bindings.txt b/Documentation/devicetree/bindings/iio/iio-bindings.txt
> >>>>> index 68d6f8ce063b..ffeae5aad8b5 100644
> >>>>> --- a/Documentation/devicetree/bindings/iio/iio-bindings.txt
> >>>>> +++ b/Documentation/devicetree/bindings/iio/iio-bindings.txt
> >>>>> @@ -18,12 +18,17 @@ Required properties:
> >>>>>                 with a single IIO output and 1 for nodes with multiple
> >>>>>                 IIO outputs.
> >>>>>
> >>>>> +Optional properties:
> >>>>> +label:                A symbolic name for the device.
> >>>>> +
> >>>>> +
> >>>>>    Example for a simple configuration with no trigger:
> >>>>>
> >>>>>      adc: voltage-sensor@35 {
> >>>>>              compatible = "maxim,max1139";
> >>>>>              reg = <0x35>;
> >>>>>              #io-channel-cells = <1>;
> >>>>> +           label = "adc_voltage_sensor";
> >>>>>      };
> >>>>>
> >>>>>    Example for a configuration with trigger:
> >>>>>  
> >>>>
> >>>> Just for the record. This patch has been created based on initial
> >>>> discussion about label property. And Rob had not problem with using
> >>>> label in connection to ina226. https://lkml.org/lkml/2019/8/27/1213  
> >>>
> >>> I didn't, but based on the name here I'm less convinced. 'label' is
> >>> supposed to be for needing to distinguish between more than 1 of
> >>> something. A name like 'adc_voltage_sensor' doesn't really.
> >>>
> >>> Rob
> >>>
> >>>  
> >>
> >> That's the problem we're try to solve. Having multiple devices and try to
> >> determine which device is which.
> >> eg: Mutliple adc's.
> >> For example I have the same dac chip on multiple boards that do different
> >> things, it's difficult to id them.
> >>
> >> so label examples could be:
> >> label = "current_control_group1";
> >> label = "voltage_control_group1";
> >>
> >> Are you totally against this or is it a problem with me not being clear
> >> with the problem and the wording of the commit message or the example?  
> > 
> > It's just the example is less than ideal. But it's just an example, so:
> > 
> > Reviewed-by: Rob Herring <robh@kernel.org>
> > 
> > Feel free to update the example if you respin.
> >   
> Thanks Rob,
> 
> I'll update the example if the series gets a respin.

Please do respin some more 'example' suited names :)

Thanks,

Jonathan

> 
> 
> 

[PATCH 2/2] iio: core: Add optional symbolic label to device attributes

[Phil Reid]

If a label is defined in the device tree for this device add that
to the device specific attributes. This is useful for userspace to
be able to identify an individual device when multiple identical
chips are present in the system.

Signed-off-by: Phil Reid <preid@electromag.com.au>
---
 drivers/iio/industrialio-core.c | 17 +++++++++++++++++
 include/linux/iio/iio.h         |  1 +
 2 files changed, 18 insertions(+)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 8303639963d7..2d7fb7629095 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -1300,6 +1300,16 @@ static ssize_t iio_show_dev_name(struct device *dev,
 
 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
 
+static ssize_t iio_show_dev_label(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->label);
+}
+
+static DEVICE_ATTR(label, S_IRUGO, iio_show_dev_label, NULL);
+
 static ssize_t iio_show_timestamp_clock(struct device *dev,
 					struct device_attribute *attr,
 					char *buf)
@@ -1416,6 +1426,8 @@ static int iio_device_register_sysfs(struct iio_dev *indio_dev)
 
 	if (indio_dev->name)
 		attrcount++;
+	if (indio_dev->label)
+		attrcount++;
 	if (clk)
 		attrcount++;
 
@@ -1438,6 +1450,8 @@ static int iio_device_register_sysfs(struct iio_dev *indio_dev)
 		indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
 	if (indio_dev->name)
 		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
+	if (indio_dev->label)
+		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
 	if (clk)
 		indio_dev->chan_attr_group.attrs[attrn++] = clk;
 
@@ -1709,6 +1723,9 @@ int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
 	if (!indio_dev->dev.of_node && indio_dev->dev.parent)
 		indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
 
+	indio_dev->label = of_get_property(indio_dev->dev.of_node, "label",
+					   NULL);
+
 	ret = iio_check_unique_scan_index(indio_dev);
 	if (ret < 0)
 		return ret;
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index a74cb177dc6f..3f89db50d3f6 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -556,6 +556,7 @@ struct iio_dev {
 	struct list_head		channel_attr_list;
 	struct attribute_group		chan_attr_group;
 	const char			*name;
+	const char			*label;
 	const struct iio_info		*info;
 	clockid_t			clock_id;
 	struct mutex			info_exist_lock;
-- 
1.8.3.1

Re: [PATCH 2/2] iio: core: Add optional symbolic label to device attributes

[Jonathan Cameron]

On Tue, 27 Aug 2019 11:35:24 +0800
Phil Reid <preid@electromag.com.au> wrote:

> If a label is defined in the device tree for this device add that
> to the device specific attributes. This is useful for userspace to
> be able to identify an individual device when multiple identical
> chips are present in the system.
> 
> Signed-off-by: Phil Reid <preid@electromag.com.au>

Looks good to me.  I like this as it finally gets us around some
perhaps slightly dubious decisions I made about the name attribute
a long time ago and the bunch of uses that don't actually conform
even to what I had in mind back then.

I'll pick it up for the 5.5 cycle once you've respun to give
more example friendly names in patch 1 and Rob is happy with it.

Thanks,

Jonathan

> ---
>  drivers/iio/industrialio-core.c | 17 +++++++++++++++++
>  include/linux/iio/iio.h         |  1 +
>  2 files changed, 18 insertions(+)
> 
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index 8303639963d7..2d7fb7629095 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -1300,6 +1300,16 @@ static ssize_t iio_show_dev_name(struct device *dev,
>  
>  static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
>  
> +static ssize_t iio_show_dev_label(struct device *dev,
> +				 struct device_attribute *attr,
> +				 char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->label);
> +}
> +
> +static DEVICE_ATTR(label, S_IRUGO, iio_show_dev_label, NULL);
> +
>  static ssize_t iio_show_timestamp_clock(struct device *dev,
>  					struct device_attribute *attr,
>  					char *buf)
> @@ -1416,6 +1426,8 @@ static int iio_device_register_sysfs(struct iio_dev *indio_dev)
>  
>  	if (indio_dev->name)
>  		attrcount++;
> +	if (indio_dev->label)
> +		attrcount++;
>  	if (clk)
>  		attrcount++;
>  
> @@ -1438,6 +1450,8 @@ static int iio_device_register_sysfs(struct iio_dev *indio_dev)
>  		indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
>  	if (indio_dev->name)
>  		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
> +	if (indio_dev->label)
> +		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
>  	if (clk)
>  		indio_dev->chan_attr_group.attrs[attrn++] = clk;
>  
> @@ -1709,6 +1723,9 @@ int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
>  	if (!indio_dev->dev.of_node && indio_dev->dev.parent)
>  		indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
>  
> +	indio_dev->label = of_get_property(indio_dev->dev.of_node, "label",
> +					   NULL);
> +
>  	ret = iio_check_unique_scan_index(indio_dev);
>  	if (ret < 0)
>  		return ret;
> diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
> index a74cb177dc6f..3f89db50d3f6 100644
> --- a/include/linux/iio/iio.h
> +++ b/include/linux/iio/iio.h
> @@ -556,6 +556,7 @@ struct iio_dev {
>  	struct list_head		channel_attr_list;
>  	struct attribute_group		chan_attr_group;
>  	const char			*name;
> +	const char			*label;
>  	const struct iio_info		*info;
>  	clockid_t			clock_id;
>  	struct mutex			info_exist_lock;

Re: [PATCH 2/2] iio: core: Add optional symbolic label to device attributes

[Michal Simek]

On 27. 08. 19 5:35, Phil Reid wrote:
> If a label is defined in the device tree for this device add that
> to the device specific attributes. This is useful for userspace to
> be able to identify an individual device when multiple identical
> chips are present in the system.
> 
> Signed-off-by: Phil Reid <preid@electromag.com.au>
> ---
>  drivers/iio/industrialio-core.c | 17 +++++++++++++++++
>  include/linux/iio/iio.h         |  1 +
>  2 files changed, 18 insertions(+)
> 
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index 8303639963d7..2d7fb7629095 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -1300,6 +1300,16 @@ static ssize_t iio_show_dev_name(struct device *dev,
>  
>  static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
>  
> +static ssize_t iio_show_dev_label(struct device *dev,
> +				 struct device_attribute *attr,
> +				 char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->label);
> +}
> +
> +static DEVICE_ATTR(label, S_IRUGO, iio_show_dev_label, NULL);
> +
>  static ssize_t iio_show_timestamp_clock(struct device *dev,
>  					struct device_attribute *attr,
>  					char *buf)
> @@ -1416,6 +1426,8 @@ static int iio_device_register_sysfs(struct iio_dev *indio_dev)
>  
>  	if (indio_dev->name)
>  		attrcount++;
> +	if (indio_dev->label)
> +		attrcount++;
>  	if (clk)
>  		attrcount++;
>  
> @@ -1438,6 +1450,8 @@ static int iio_device_register_sysfs(struct iio_dev *indio_dev)
>  		indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
>  	if (indio_dev->name)
>  		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
> +	if (indio_dev->label)
> +		indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
>  	if (clk)
>  		indio_dev->chan_attr_group.attrs[attrn++] = clk;
>  
> @@ -1709,6 +1723,9 @@ int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
>  	if (!indio_dev->dev.of_node && indio_dev->dev.parent)
>  		indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
>  
> +	indio_dev->label = of_get_property(indio_dev->dev.of_node, "label",
> +					   NULL);
> +
>  	ret = iio_check_unique_scan_index(indio_dev);
>  	if (ret < 0)
>  		return ret;
> diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
> index a74cb177dc6f..3f89db50d3f6 100644
> --- a/include/linux/iio/iio.h
> +++ b/include/linux/iio/iio.h
> @@ -556,6 +556,7 @@ struct iio_dev {
>  	struct list_head		channel_attr_list;
>  	struct attribute_group		chan_attr_group;
>  	const char			*name;
> +	const char			*label;
>  	const struct iio_info		*info;
>  	clockid_t			clock_id;
>  	struct mutex			info_exist_lock;
> 

Tested-by: Michal Simek <michal.simek@xilinx.com>

Thanks,
Michal