hwmon: (pmbus) Fix LINEAR16 data format

LINEAR16 data format is unsigned, not signed. Impact is that affected attributes report negative values in the upper half of the supported value range. Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

hwmon: (pmbus) Fix LINEAR16 data format
LINEAR16 data format is unsigned, not signed. Impact is that affected attributes report negative values in the upper half of the supported value range. Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Guenter Roeck
1 parent 8677011a5d
Showing 1 changed file with 17 additions and 14 deletions Side-by-side Diff
drivers/hwmon/pmbus_core.c
@@ -359,20 +359,21 @@
 static int pmbus_reg2data_linear(struct pmbus_data *data,
 				 struct pmbus_sensor *sensor)
 {
-	s16 exponent, mantissa;
+	s16 exponent;
+	s32 mantissa;
 	long val;
  
-	if (sensor->class == PSC_VOLTAGE_OUT) {
+	if (sensor->class == PSC_VOLTAGE_OUT) {	/* LINEAR16 */
 		exponent = data->exponent;
-		mantissa = (s16) sensor->data;
-	} else {
+		mantissa = (u16) sensor->data;
+	} else {				/* LINEAR11 */
 		exponent = (sensor->data >> 11) & 0x001f;
 		mantissa = sensor->data & 0x07ff;
  
 		if (exponent > 0x0f)
 			exponent |= 0xffe0;	/* sign extend exponent */
 		if (mantissa > 0x03ff)
-			mantissa |= 0xf800;	/* sign extend mantissa */
+			mantissa |= 0xfffff800;	/* sign extend mantissa */
 	}
  
 	val = mantissa;
  
  
@@ -454,19 +455,18 @@
 static u16 pmbus_data2reg_linear(struct pmbus_data *data,
 				 enum pmbus_sensor_classes class, long val)
 {
-	s16 exponent = 0, mantissa = 0;
+	s16 exponent = 0, mantissa;
 	bool negative = false;
  
 	/* simple case */
 	if (val == 0)
 		return 0;
  
-	if (val < 0) {
-		negative = true;
-		val = -val;
-	}
-
 	if (class == PSC_VOLTAGE_OUT) {
+		/* LINEAR16 does not support negative voltages */
+		if (val < 0)
+			return 0;
+
 		/*
 		 * For a static exponents, we don't have a choice
 		 * but to adjust the value to it.
@@ -476,9 +476,12 @@
 		else
 			val >>= data->exponent;
 		val = DIV_ROUND_CLOSEST(val, 1000);
-		if (val > 0x7fff)
-			val = 0x7fff;
-		return negative ? -val : val;
+		return val & 0xffff;
+	}
+
+	if (val < 0) {
+		negative = true;
+		val = -val;
 	}
  
 	/* Power is in uW. Convert to mW before converting. */
...	...	@@ -359,20 +359,21 @@
359	359	static int pmbus_reg2data_linear(struct pmbus_data *data,
360	360	struct pmbus_sensor *sensor)
361	361	{
362		- s16 exponent, mantissa;
	362	+ s16 exponent;
	363	+ s32 mantissa;
363	364	long val;
364	365
365		- if (sensor->class == PSC_VOLTAGE_OUT) {
	366	+ if (sensor->class == PSC_VOLTAGE_OUT) { /* LINEAR16 */
366	367	exponent = data->exponent;
367		- mantissa = (s16) sensor->data;
368		- } else {
	368	+ mantissa = (u16) sensor->data;
	369	+ } else { /* LINEAR11 */
369	370	exponent = (sensor->data >> 11) & 0x001f;
370	371	mantissa = sensor->data & 0x07ff;
371	372
372	373	if (exponent > 0x0f)
373	374	exponent \|= 0xffe0; /* sign extend exponent */
374	375	if (mantissa > 0x03ff)
375		- mantissa \|= 0xf800; /* sign extend mantissa */
	376	+ mantissa \|= 0xfffff800; /* sign extend mantissa */
376	377	}
377	378
378	379	val = mantissa;
379	380
380	381
...	...	@@ -454,19 +455,18 @@
454	455	static u16 pmbus_data2reg_linear(struct pmbus_data *data,
455	456	enum pmbus_sensor_classes class, long val)
456	457	{
457		- s16 exponent = 0, mantissa = 0;
	458	+ s16 exponent = 0, mantissa;
458	459	bool negative = false;
459	460
460	461	/* simple case */
461	462	if (val == 0)
462	463	return 0;
463	464
464		- if (val < 0) {
465		- negative = true;
466		- val = -val;
467		- }
468		-
469	465	if (class == PSC_VOLTAGE_OUT) {
	466	+ /* LINEAR16 does not support negative voltages */
	467	+ if (val < 0)
	468	+ return 0;
	469	+
470	470	/*
471	471	* For a static exponents, we don't have a choice
472	472	* but to adjust the value to it.
...	...	@@ -476,9 +476,12 @@
476	476	else
477	477	val >>= data->exponent;
478	478	val = DIV_ROUND_CLOSEST(val, 1000);
479		- if (val > 0x7fff)
480		- val = 0x7fff;
481		- return negative ? -val : val;
	479	+ return val & 0xffff;
	480	+ }
	481	+
	482	+ if (val < 0) {
	483	+ negative = true;
	484	+ val = -val;
482	485	}
483	486
484	487	/* Power is in uW. Convert to mW before converting. */