Commit ac778e62 authored by Florian Fainelli's avatar Florian Fainelli Committed by Sudeep Holla
Browse files

hwmon: scmi: Scale values to target desired HWMON units 



If the SCMI firmware implementation is reporting values in a scale that
is different from the HWMON units, we need to scale up or down the value
according to how far apart they are.

Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
[sudeep.holla: added check of scale = 0 for early exit in scmi_hwmon_scale]
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
parent 0b673b64

drivers/hwmon/scmi-hwmon.c

+48 −0
Original line number Diff line number Diff line
@@ -18,6 +18,50 @@ struct scmi_sensors { 
	const struct scmi_sensor_info **info[hwmon_max];

};



static inline u64 __pow10(u8 x)

{

	u64 r = 1;



	while (x--)

		r *= 10;



	return r;

}



static int scmi_hwmon_scale(const struct scmi_sensor_info *sensor, u64 *value)

{

	s8 scale = sensor->scale;

	u64 f;



	switch (sensor->type) {

	case TEMPERATURE_C:

	case VOLTAGE:

	case CURRENT:

		scale += 3;

		break;

	case POWER:

	case ENERGY:

		scale += 6;

		break;

	default:

		break;

	}



	if (scale == 0)

		return 0;



	if (abs(scale) > 19)

		return -E2BIG;



	f = __pow10(abs(scale));

	if (scale > 0)

		*value *= f;

	else

		*value = div64_u64(*value, f);



	return 0;

}



static int scmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,

			   u32 attr, int channel, long *val)

{
@@ -29,6 +73,10 @@ static int scmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type, 


	sensor = *(scmi_sensors->info[type] + channel);

	ret = h->sensor_ops->reading_get(h, sensor->id, false, &value);

	if (ret)

		return ret;



	ret = scmi_hwmon_scale(sensor, &value);

	if (!ret)

		*val = value;

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