Re: [PATCH v1] hwmon: (iio_hwmon) Enable power exporting from IIO

[Guenter Roeck <linux@roeck-us.net>]

On Thu, Aug 22, 2019 at 04:22:24PM +0200, Michal Simek wrote:
> There is no reason why power channel shouldn't be exported as is done for
> voltage, current, temperature and humidity.
> 
> Power channel is available on iio ina226 driver.
> 
> Sysfs IIO documentation for power attribute added by commit 7c6d5c7ee883
> ("iio: Documentation: Add missing documentation for power attribute")
> is declaring that value is in mili-Watts but hwmon interface is expecting
> value in micro-Watts that's why there is a need for mili-Watts to
> micro-Watts conversion.
> 
> Tested on Xilinx ZCU102 board.
> 
> Signed-off-by: Michal Simek <michal.simek@xilinx.com>

Applied to hwmon-next.

Thanks,
Guenter

> ---
> 
> Changes in v1:
> - from RFC - fix power conversion mili-Watts to micro-Watts
> 
>  drivers/hwmon/iio_hwmon.c | 18 +++++++++++++++---
>  1 file changed, 15 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/hwmon/iio_hwmon.c b/drivers/hwmon/iio_hwmon.c
> index f1c2d5faedf0..b85a125dd86f 100644
> --- a/drivers/hwmon/iio_hwmon.c
> +++ b/drivers/hwmon/iio_hwmon.c
> @@ -44,12 +44,20 @@ static ssize_t iio_hwmon_read_val(struct device *dev,
>  	int ret;
>  	struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
>  	struct iio_hwmon_state *state = dev_get_drvdata(dev);
> +	struct iio_channel *chan = &state->channels[sattr->index];
> +	enum iio_chan_type type;
> +
> +	ret = iio_read_channel_processed(chan, &result);
> +	if (ret < 0)
> +		return ret;
>  
> -	ret = iio_read_channel_processed(&state->channels[sattr->index],
> -					&result);
> +	ret = iio_get_channel_type(chan, &type);
>  	if (ret < 0)
>  		return ret;
>  
> +	if (type == IIO_POWER)
> +		result *= 1000; /* mili-Watts to micro-Watts conversion */
> +
>  	return sprintf(buf, "%d\n", result);
>  }
>  
> @@ -59,7 +67,7 @@ static int iio_hwmon_probe(struct platform_device *pdev)
>  	struct iio_hwmon_state *st;
>  	struct sensor_device_attribute *a;
>  	int ret, i;
> -	int in_i = 1, temp_i = 1, curr_i = 1, humidity_i = 1;
> +	int in_i = 1, temp_i = 1, curr_i = 1, humidity_i = 1, power_i = 1;
>  	enum iio_chan_type type;
>  	struct iio_channel *channels;
>  	struct device *hwmon_dev;
> @@ -114,6 +122,10 @@ static int iio_hwmon_probe(struct platform_device *pdev)
>  			n = curr_i++;
>  			prefix = "curr";
>  			break;
> +		case IIO_POWER:
> +			n = power_i++;
> +			prefix = "power";
> +			break;
>  		case IIO_HUMIDITYRELATIVE:
>  			n = humidity_i++;
>  			prefix = "humidity";