8 //      http://www.apache.org/licenses/LICENSE-2.0
17 #include "dbus-sdr/sensorutils.hpp"
19 #include <phosphor-logging/lg2.hpp>
28 static bool baseInRange(double base)  in baseInRange()
30     auto min10 = static_cast<double>(minInt10);  in baseInRange()
31     auto max10 = static_cast<double>(maxInt10);  in baseInRange()
37 // Ensures floating-point "base" is within bounds,
40 // the floating-point "base" will be as large as possible,
47 // Returns true if successful, modifies values in-place
48 static bool scaleFloatExp(double& base, int8_t& expShift)  in scaleFloatExp()
50     // Comparing with zero should be OK, zero is special in floating-point  in scaleFloatExp()
57     // As long as base value is within allowed range, expand precision  in scaleFloatExp()
69         --expShift;  in scaleFloatExp()
72     // As long as base value is *not* within range, shrink precision  in scaleFloatExp()
73     // This will pull base value closer to zero, thus within range  in scaleFloatExp()
87     // If the above loop was not able to pull it back within range,  in scaleFloatExp()
100 // Also modify floating-point "dbase" at the same time,
101 // as both integer and floating-point base share the same expShift.
104 // Always successful, modifies values in-place
105 static void normalizeIntExp(int16_t& ibase, int8_t& expShift, double& dbase)  in normalizeIntExp()
131         // The floating-point base must be kept in sync with the integer base,  in normalizeIntExp()
132         // as both floating-point and integer share the same exponent.  in normalizeIntExp()
142 …el.com/content/dam/www/public/us/en/documents/product-briefs/ipmi-second-gen-interface-spec-v2-rev…
151 bool getSensorAttributes(const double max, const double min, int16_t& mValue,  in getSensorAttributes()
174     // y comes in from D-Bus (the actual sensor reading)  in getSensorAttributes()
176     // If y is min, x should equal = 0 (or -128 if signed)  in getSensorAttributes()
178     double fullRange = max - min;  in getSensorAttributes()
179     double lowestX;  in getSensorAttributes()
193         // TODO(): It would be worth experimenting with the range (-127,127),  in getSensorAttributes()
194         // instead of the range (-128,127), because this  in getSensorAttributes()
196         // Divide by 254 instead of 255, and change -128 to -127 elsewhere.  in getSensorAttributes()
198         lowestX = -128.0;  in getSensorAttributes()
206     // Step 1: Set y to (max - min), set x to 255, set B to 0, solve for M  in getSensorAttributes()
208     // because total range is the same.  in getSensorAttributes()
209     double dM = fullRange / 255.0;  in getSensorAttributes()
215             "getSensorAttributes: Multiplier range exceeds scale (M={DM}, "  in getSensorAttributes()
228         lg2::error("getSensorAttributes: Multiplier range below scale");  in getSensorAttributes()
233     // If negative, x will be -128 (the most negative possible byte), not 0  in getSensorAttributes()
237     // B = 10^(-rExp - bExp) (y - M 10^rExp x)  in getSensorAttributes()
239 …rtC1LLNJQr1TX5KqAMCuATF8I0xfIdIIwnYDMIteKAggPxAIKJMEFkiACxfk5Zaka0ZUKtrYKGhq-CloKFZoK2goaTkCWhqGBg…  in getSensorAttributes()
240     double dB = std::pow(10.0, ((-rExp) - bExp)) *  in getSensorAttributes()
241                 (min - ((dM * std::pow(10.0, rExp) * lowestX)));  in getSensorAttributes()
247             "getSensorAttributes: Offset range exceeds scale (B={DB}, "  in getSensorAttributes()
261 uint8_t scaleIPMIValueFromDouble(const double value, const int16_t mValue,  in scaleIPMIValueFromDouble()
271     auto dM = static_cast<double>(mValue);  in scaleIPMIValueFromDouble()
272     auto dB = static_cast<double>(bValue);  in scaleIPMIValueFromDouble()
276     // x = (10^(-rExp) (y - B 10^(rExp + bExp)))/M and M 10^rExp!=0  in scaleIPMIValueFromDouble()
278 …rtC1LLNJQr1TX5KqAMCuATF8I0xfIdIIwnYDMIteKAggPxAIKJMEFkiACxfk5Zaka0ZUKtrYKGhq-CloKFZoK2goaTkCWhqGBg…  in scaleIPMIValueFromDouble()
279     double dX =  in scaleIPMIValueFromDouble()
280         (std::pow(10.0, -rExp) * (value - (dB * std::pow(10.0, rExp + bExp)))) /  in scaleIPMIValueFromDouble()
289     // sometimes the resulting byte is slightly out of range.  in scaleIPMIValueFromDouble()
290     // Still allow this, but clamp the values to range.  in scaleIPMIValueFromDouble()
309 uint8_t getScaledIPMIValue(const double value, const double max,  in getScaledIPMIValue()
310                            const double min)  in getScaledIPMIValue()