| Message ID | 20170303091449.3512-3-carlo@caione.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
Carlo Caione <carlo@caione.org> writes: > From: Carlo Caione <carlo@endlessm.com> > > The implementation details for SCPI seems to suggest that the sensor > readings must be reported by SCP using a well defined scale > (millidegree Celsius for temperature, millivolts for voltage, > milliamperes for current, microwatts for power and microjoules for > energy). > > This is also important for the interaction with other subsystems: for > example both the thermal sub-system and the hwmon sysfs interface expect > the temperature expressed in millidegree Celsius. > > Unfortunately since this behaviour is dependent on the firmware > implementation there are cases where the sensor readings are reported > using a different scale. For example in the Amlogic SoCs the > temperature is reported in degree and not millidegree Celsius. > > To take into account this discrepancy and fixup the values reported by > SCP a new DT property `scpi,sensors-scale' is introduced and used in > this patch by the scpi-hwmon driver to convert the sensor readings to > the expected scale. > > Signed-off-by: Carlo Caione <carlo@endlessm.com> > --- > drivers/hwmon/scpi-hwmon.c | 34 ++++++++++++++++++++++++++++++++++ > 1 file changed, 34 insertions(+) > > diff --git a/drivers/hwmon/scpi-hwmon.c b/drivers/hwmon/scpi-hwmon.c > index 094f948f99ff..b64fe7d10742 100644 > --- a/drivers/hwmon/scpi-hwmon.c > +++ b/drivers/hwmon/scpi-hwmon.c > @@ -23,6 +23,7 @@ > #include <linux/thermal.h> > > struct sensor_data { > + unsigned int scale; > struct scpi_sensor_info info; > struct device_attribute dev_attr_input; > struct device_attribute dev_attr_label; > @@ -44,6 +45,22 @@ struct scpi_sensors { > const struct attribute_group *groups[2]; > }; > > +static const u32 scpi_scale[] = { > + [TEMPERATURE] = 1000, /* (millicelsius) */ > + [VOLTAGE] = 1000, /* (millivolts) */ > + [CURRENT] = 1000, /* (milliamperes) */ > + [POWER] = 1000000, /* (microwatts) */ > + [ENERGY] = 1000000, /* (microjoules) */ > +}; > + > +void scpi_scale_reading(u64 *value, struct sensor_data *sensor) This function is not intended for use outside this file. Please mark as static. > +{ > + if (scpi_scale[sensor->info.class] != sensor->scale) { > + *value *= scpi_scale[sensor->info.class]; > + do_div(*value, sensor->scale); > + } > +} > + > static int scpi_read_temp(void *dev, int *temp) > { > struct scpi_thermal_zone *zone = dev; > @@ -57,6 +74,8 @@ static int scpi_read_temp(void *dev, int *temp) > if (ret) > return ret; > > + scpi_scale_reading(&value, sensor); > + > *temp = value; > return 0; > } > @@ -77,6 +96,8 @@ scpi_show_sensor(struct device *dev, struct device_attribute *attr, char *buf) > if (ret) > return ret; > > + scpi_scale_reading(&value, sensor); > + > return sprintf(buf, "%llu\n", value); > } > > @@ -97,6 +118,7 @@ static struct thermal_zone_of_device_ops scpi_sensor_ops = { > static int scpi_hwmon_probe(struct platform_device *pdev) > { > u16 nr_sensors, i; > + u32 scale[] = { 1000, 1000, 1000, 1000000, 1000000 }; > int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0; > int num_energy = 0; > struct scpi_ops *scpi_ops; > @@ -131,6 +153,16 @@ static int scpi_hwmon_probe(struct platform_device *pdev) > > scpi_sensors->scpi_ops = scpi_ops; > > + of_property_read_u32_array(dev->of_node, "scpi,sensors-scale", > + scale, ARRAY_SIZE(scale)); > + > + for (i = 0; i < ARRAY_SIZE(scale); i++) { > + if (!scale[i]) { > + dev_err(dev, "%s: scale cannot be zero (%d)\n", __func__, i); > + return -EINVAL; > + } > + } > + > for (i = 0, idx = 0; i < nr_sensors; i++) { > struct sensor_data *sensor = &scpi_sensors->data[idx]; > > @@ -178,6 +210,8 @@ static int scpi_hwmon_probe(struct platform_device *pdev) > continue; > } > > + sensor->scale = scale[sensor->info.class]; > + > sensor->dev_attr_input.attr.mode = S_IRUGO; > sensor->dev_attr_input.show = scpi_show_sensor; > sensor->dev_attr_input.attr.name = sensor->input; So with the function marked as static, Acked-by: Punit Agrawal <punit.agrawal@arm.com> -- To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/hwmon/scpi-hwmon.c b/drivers/hwmon/scpi-hwmon.c index 094f948f99ff..b64fe7d10742 100644 --- a/drivers/hwmon/scpi-hwmon.c +++ b/drivers/hwmon/scpi-hwmon.c @@ -23,6 +23,7 @@ #include <linux/thermal.h> struct sensor_data { + unsigned int scale; struct scpi_sensor_info info; struct device_attribute dev_attr_input; struct device_attribute dev_attr_label; @@ -44,6 +45,22 @@ struct scpi_sensors { const struct attribute_group *groups[2]; }; +static const u32 scpi_scale[] = { + [TEMPERATURE] = 1000, /* (millicelsius) */ + [VOLTAGE] = 1000, /* (millivolts) */ + [CURRENT] = 1000, /* (milliamperes) */ + [POWER] = 1000000, /* (microwatts) */ + [ENERGY] = 1000000, /* (microjoules) */ +}; + +void scpi_scale_reading(u64 *value, struct sensor_data *sensor) +{ + if (scpi_scale[sensor->info.class] != sensor->scale) { + *value *= scpi_scale[sensor->info.class]; + do_div(*value, sensor->scale); + } +} + static int scpi_read_temp(void *dev, int *temp) { struct scpi_thermal_zone *zone = dev; @@ -57,6 +74,8 @@ static int scpi_read_temp(void *dev, int *temp) if (ret) return ret; + scpi_scale_reading(&value, sensor); + *temp = value; return 0; } @@ -77,6 +96,8 @@ scpi_show_sensor(struct device *dev, struct device_attribute *attr, char *buf) if (ret) return ret; + scpi_scale_reading(&value, sensor); + return sprintf(buf, "%llu\n", value); } @@ -97,6 +118,7 @@ static struct thermal_zone_of_device_ops scpi_sensor_ops = { static int scpi_hwmon_probe(struct platform_device *pdev) { u16 nr_sensors, i; + u32 scale[] = { 1000, 1000, 1000, 1000000, 1000000 }; int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0; int num_energy = 0; struct scpi_ops *scpi_ops; @@ -131,6 +153,16 @@ static int scpi_hwmon_probe(struct platform_device *pdev) scpi_sensors->scpi_ops = scpi_ops; + of_property_read_u32_array(dev->of_node, "scpi,sensors-scale", + scale, ARRAY_SIZE(scale)); + + for (i = 0; i < ARRAY_SIZE(scale); i++) { + if (!scale[i]) { + dev_err(dev, "%s: scale cannot be zero (%d)\n", __func__, i); + return -EINVAL; + } + } + for (i = 0, idx = 0; i < nr_sensors; i++) { struct sensor_data *sensor = &scpi_sensors->data[idx]; @@ -178,6 +210,8 @@ static int scpi_hwmon_probe(struct platform_device *pdev) continue; } + sensor->scale = scale[sensor->info.class]; + sensor->dev_attr_input.attr.mode = S_IRUGO; sensor->dev_attr_input.show = scpi_show_sensor; sensor->dev_attr_input.attr.name = sensor->input;