Re: [PATCH] hwmon: ina2xx: Add per-sensor label

[Marc Titinger <mtitinger@baylibre.com>]

On 03/03/2016 22:02, Anatol Pomozov wrote:
> From: Anatol Pomazau <anatol@google.com>
>
> Some systems have a lot of power sensors and having an way to label sensor
> makes easier to use sensor information.
>
> Add dts property 'label' that is readable via device sysfs file 'label'.

Hi Anatol and all,

I haven't looked how to do that, but if this label was to extend the 
chip name instead, could this benefit to any existing client app already ?

Cheers,
Marc.

>
> Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
> ---
>   Documentation/devicetree/bindings/hwmon/ina2xx.txt |  3 +++
>   drivers/hwmon/ina2xx.c                             | 19 +++++++++++++++++++
>   2 files changed, 22 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/hwmon/ina2xx.txt b/Documentation/devicetree/bindings/hwmon/ina2xx.txt
> index 9bcd5e8..76315e2 100644
> --- a/Documentation/devicetree/bindings/hwmon/ina2xx.txt
> +++ b/Documentation/devicetree/bindings/hwmon/ina2xx.txt
> @@ -11,6 +11,9 @@ Required properties:
>   
>   Optional properties:
>   
> +- label
> +	Human readable identifier for the sensor. Readable via sysfs file 'label'.
> +
>   - shunt-resistor
>   	Shunt resistor value in micro-Ohm
>   
> diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
> index b24f1d3..6e15115 100644
> --- a/drivers/hwmon/ina2xx.c
> +++ b/drivers/hwmon/ina2xx.c
> @@ -108,6 +108,7 @@ struct ina2xx_data {
>   	long rshunt;
>   	struct mutex config_lock;
>   	struct regmap *regmap;
> +	const char *label;
>   
>   	const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS];
>   };
> @@ -368,6 +369,21 @@ static ssize_t ina226_show_interval(struct device *dev,
>   	return snprintf(buf, PAGE_SIZE, "%d\n", ina226_reg_to_interval(regval));
>   }
>   
> +static ssize_t ina2xx_show_label(struct device *dev,
> +			struct device_attribute *da, char *buf)
> +{
> +	struct ina2xx_data *data = dev_get_drvdata(dev);
> +	ssize_t ret = 0;
> +
> +	if (data->label)
> +		ret = scnprintf(buf, PAGE_SIZE, "%s\n", data->label);
> +
> +	return ret;
> +}
> +
> +/* label */
> +static SENSOR_DEVICE_ATTR(label, S_IRUGO, ina2xx_show_label, NULL,  0);
> +
>   /* shunt voltage */
>   static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina2xx_show_value, NULL,
>   			  INA2XX_SHUNT_VOLTAGE);
> @@ -395,6 +411,7 @@ static SENSOR_DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR,
>   
>   /* pointers to created device attributes */
>   static struct attribute *ina2xx_attrs[] = {
> +	&sensor_dev_attr_label.dev_attr.attr,
>   	&sensor_dev_attr_in0_input.dev_attr.attr,
>   	&sensor_dev_attr_in1_input.dev_attr.attr,
>   	&sensor_dev_attr_curr1_input.dev_attr.attr,
> @@ -432,6 +449,8 @@ static int ina2xx_probe(struct i2c_client *client,
>   	/* set the device type */
>   	data->config = &ina2xx_config[id->driver_data];
>   
> +	of_property_read_string(dev->of_node, "label", &data->label);
> +
>   	if (of_property_read_u32(dev->of_node, "shunt-resistor", &val) < 0) {
>   		struct ina2xx_platform_data *pdata = dev_get_platdata(dev);
>