Hi Florian,
On 5/6/19 3:41 PM, Florian Fainelli wrote:
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 appart they are.
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
drivers/hwmon/scmi-hwmon.c | 55 +++++++++++++++++++++++++++++++-------
1 file changed, 46 insertions(+), 9 deletions(-)
diff --git a/drivers/hwmon/scmi-hwmon.c b/drivers/hwmon/scmi-hwmon.c
index a80183a488c5..e9913509cb88 100644
--- a/drivers/hwmon/scmi-hwmon.c
+++ b/drivers/hwmon/scmi-hwmon.c
@@ -18,6 +18,51 @@ struct scmi_sensors {
const struct scmi_sensor_info **info[hwmon_max];
};
+static enum hwmon_sensor_types scmi_types[] = {
+ [TEMPERATURE_C] = hwmon_temp,
+ [VOLTAGE] = hwmon_in,
+ [CURRENT] = hwmon_curr,
+ [POWER] = hwmon_power,
+ [ENERGY] = hwmon_energy,
+};
+
+static u64 scmi_hwmon_scale(const struct scmi_sensor_info *sensor, u64 value)
+{
+ u64 scaled_value = value;
I don't think that variable is necessary.
+ s8 desired_scale;
Just scale ? Also, you could assign scale here directly, and subtract
the offset below. Then "n" would not be necessary.
Such as
s8 scale = sensor->scale; // assuming scale is s8
...
case CURRENT:
scale += 3;
...
That would also be less confusing, since it would avoid the double
negation.
+ int n, p;
+
+ switch (sensor->type) {
+ case TEMPERATURE_C:
+ case VOLTAGE:
+ case CURRENT:
+ /* fall through */
Unnecessary comment
+ desired_scale = -3;
+ break;
+ case POWER:
+ case ENERGY:
+ /* fall through */
Unnecessary comment.
+ desired_scale = -6;
+ break;
+ default:
+ return scaled_value;
Here we presumably want a scale of 0. However, if the scale passed
from SCMI is, say, -5 or +5, we return the original (unadjusted)
value. Seems to me we would still want to adjust the value to match
hwmon expectations. Am I missing something ?
+ }
+
+ n = (s8)sensor->scale - desired_scale;
+ if (n == 0)
Indentation seems off here.
+ return scaled_value;
+
+ for (p = 0; p < abs(n); p++) {
+ /* Need to scale up from sensor to HWMON */
+ if (n > 0)
+ scaled_value *= 10;
+ else
+ do_div(scaled_value, 10);
+ }
Something like
factor = pow10(abs(scale));
if (scale > 0)
value *= factor;
else
do_div(value, factor);
would avoid the repeated abs() and do_div(). Unfortunately there is
no pow10() helper, so you would have to write that. Still, I think
that would be much more efficient.
Thanks,
Guenter
+
+ return scaled_value;
+}
+
static int scmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
@@ -30,7 +75,7 @@ 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)
- *val = value;
+ *val = scmi_hwmon_scale(sensor, value);
return ret;
}
@@ -91,14 +136,6 @@ static int scmi_hwmon_add_chan_info(struct hwmon_channel_info *scmi_hwmon_chan,
return 0;
}
-static enum hwmon_sensor_types scmi_types[] = {
- [TEMPERATURE_C] = hwmon_temp,
- [VOLTAGE] = hwmon_in,
- [CURRENT] = hwmon_curr,
- [POWER] = hwmon_power,
- [ENERGY] = hwmon_energy,
-};
-
static u32 hwmon_attributes[] = {
[hwmon_chip] = HWMON_C_REGISTER_TZ,
[hwmon_temp] = HWMON_T_INPUT | HWMON_T_LABEL,
