diff --git a/kernel/chips/adm9240.c b/kernel/chips/adm9240.c
index ef0e53ac..8e00b796 100644
--- a/kernel/chips/adm9240.c
+++ b/kernel/chips/adm9240.c
@@ -116,8 +116,19 @@
 #define IN_TO_REG(val,nr) ((val) & 0xff)
 #define IN_FROM_REG(val,nr) (val)
 
-#define FAN_TO_REG(val,div) ((val)==0?255:\
-                             ((1350000+(val)*(div)/2)/((val)*(div))) & 0xff)
+static inline unsigned char
+FAN_TO_REG (unsigned rpm, unsigned divisor)
+{
+  unsigned val;
+  
+  if (rpm == 0)
+      return 255;
+
+  val = (1350000 + rpm * divisor / 2) / (rpm * divisor);
+  if (val > 255)
+      val = 255;
+  return val;
+}
 #define FAN_FROM_REG(val,div) ((val)==0?-1:\
                                (val)==255?0:1350000/((div)*(val)))
 
diff --git a/kernel/chips/gl518sm.c b/kernel/chips/gl518sm.c
index bf58b227..3f311191 100644
--- a/kernel/chips/gl518sm.c
+++ b/kernel/chips/gl518sm.c
@@ -63,8 +63,19 @@
 #define TEMP_TO_REG(val) (((((val)<0?(val)-5:(val)+5) / 10) + 119) & 0xff)
 #define TEMP_FROM_REG(val) (((val) - 119) * 10)
 
-#define FAN_TO_REG(val,div) \
- (( (val)==0 ? 255 : ((960000+(val)*(div))/(2*(val)*(div))) ) & 0xff)
+static inline unsigned char
+FAN_TO_REG (unsigned rpm, unsigned divisor)
+{
+  unsigned val;
+  
+  if (rpm == 0)
+      return 255;
+
+  val = (960000 + rpm * divisor) / (2 * rpm * divisor);
+  if (val > 255)
+      val = 255;
+  return val;
+}
 #define FAN_FROM_REG(val,div) \
  ( (val)==0 ? 0 : (val)==255 ? 0 : (960000/(2*(val)*(div))) )
 
diff --git a/kernel/chips/lm78.c b/kernel/chips/lm78.c
index ee836607..b3aca3a0 100644
--- a/kernel/chips/lm78.c
+++ b/kernel/chips/lm78.c
@@ -76,8 +76,19 @@ SENSORS_INSMOD_3(lm78,lm78j,lm79);
 #define IN_TO_REG(val)  (((val) * 10 + 8)/16)
 #define IN_FROM_REG(val) (((val) *  16) / 10)
 
-#define FAN_TO_REG(val,div) ((val)==0?255:((1350000+(val)*(div)/2)/\
-                            ((val)*(div))) & 0xff)
+static inline unsigned char
+FAN_TO_REG (unsigned rpm, unsigned divisor)
+{
+  unsigned val;
+  
+  if (rpm == 0)
+      return 255;
+
+  val = (1350000 + rpm * divisor / 2) / (rpm * divisor);
+  if (val > 255)
+      val = 255;
+  return val;
+}
 #define FAN_FROM_REG(val,div) ((val)==0?-1:(val)==255?0:1350000/((val)*(div)))
 
 #define TEMP_TO_REG(val) (((val)<0?(((val)-5)/10)&0xff:((val)+5)/10) & 0xff)
diff --git a/kernel/chips/lm80.c b/kernel/chips/lm80.c
index c493acf8..5576f418 100644
--- a/kernel/chips/lm80.c
+++ b/kernel/chips/lm80.c
@@ -65,8 +65,19 @@
 #define IN_TO_REG(val,nr) ((val) & 0xff)
 #define IN_FROM_REG(val,nr) (val)
 
-#define FAN_TO_REG(val,div) ((val)==0?255:\
-                             ((1350000+(val)*(div)/2)/((val)*(div))) & 0xff)
+static inline unsigned char
+FAN_TO_REG (unsigned rpm, unsigned divisor)
+{
+  unsigned val;
+  
+  if (rpm == 0)
+      return 255;
+
+  val = (1350000 + rpm * divisor / 2) / (rpm * divisor);
+  if (val > 255)
+      val = 255;
+  return val;
+}
 #define FAN_FROM_REG(val,div) ((val)==0?-1:\
                                (val)==255?0:1350000/((div)*(val)))
 
diff --git a/kernel/chips/maxilife.c b/kernel/chips/maxilife.c
index 1a65b157..1cfda0da 100644
--- a/kernel/chips/maxilife.c
+++ b/kernel/chips/maxilife.c
@@ -85,7 +85,19 @@ static const char *version = "1.00 25/2/99 Fons Rademakers";
                                /* 19531 / val * 60 == 1171860 / val */
 #define FAN_FROM_REG(val)      ((val)==0xfe ? -1 : (val)==0xff ? 0 : \
                                 (1171860 / (val)))
-#define FAN_TO_REG(val)        (1171860 / (val))
+static inline unsigned char
+FAN_TO_REG (unsigned rpm)
+{
+  unsigned val;
+  
+  if (rpm == 0)
+      return 255;
+
+  val = 1171860 / rpm;
+  if (val > 255)
+      val = 255;
+  return val;
+}
 
 #define TEMP_FROM_REG(val)     ((val) * 5)
 #define TEMP_TO_REG(val)       ((val) / 5)
diff --git a/kernel/chips/sis5595.c b/kernel/chips/sis5595.c
index 83b8807e..8a9b156f 100644
--- a/kernel/chips/sis5595.c
+++ b/kernel/chips/sis5595.c
@@ -79,8 +79,19 @@
 #define IN_TO_REG(val)  (((val) * 10 + 8)/16)
 #define IN_FROM_REG(val) (((val) *  16) / 10)
 
-#define FAN_TO_REG(val,div) ((val)==0?255:((1350000+(val)*(div)/2)/\
-                            ((val)*(div))) & 0xff)
+static inline unsigned char
+FAN_TO_REG (unsigned rpm, unsigned divisor)
+{
+  unsigned val;
+  
+  if (rpm == 0)
+      return 255;
+
+  val = (1350000 + rpm * divisor / 2) / (rpm * divisor);
+  if (val > 255)
+      val = 255;
+  return val;
+}
 #define FAN_FROM_REG(val,div) ((val)==0?-1:(val)==255?0:1350000/((val)*(div)))
 
 #define TEMP_TO_REG(val) (((val)<0?(((val)-5)/10)&0xff:((val)+5)/10) & 0xff)
diff --git a/kernel/chips/w83781d.c b/kernel/chips/w83781d.c
index 523a3d7d..fc24da96 100644
--- a/kernel/chips/w83781d.c
+++ b/kernel/chips/w83781d.c
@@ -114,9 +114,20 @@ const u8 regpwm[] = {W83781D_REG_PWM1, W83781D_REG_PWM2, W83781D_REG_PWM3, W8378
 #define IN_TO_REG(val,nr) (((val) * 10 + 8)/16)
 #define IN_FROM_REG(val,nr) (((val) * 16) / 10)
 
-#define FAN_TO_REG(val,div) ((val)==0?255:((1350000+(val)*(div)/2)/\
-                            ((val)*(div))) & 0xff)
-#define FAN_FROM_REG(val,div) ((val)==0?-1:(val)==255?0:1350000/((val)*2*(div)))
+static inline unsigned char
+FAN_TO_REG (unsigned rpm, unsigned divisor)
+{
+  unsigned val;
+  
+  if (rpm == 0)
+      return 255;
+
+  val = (1350000 + rpm * divisor / 2) / (rpm * divisor);
+  if (val > 255)
+      val = 255;
+  return val;
+}
+#define FAN_FROM_REG(val,div) ((val)==0?-1:(val)==255?0:1350000/((val)*(div)))
 
 #define TEMP_TO_REG(val) (((val)<0?(((val)-5)/10)&0xff:((val)+5)/10) & 0xff)
 #define TEMP_FROM_REG(val) (((val)>0x80?(val)-0x100:(val))*10)