hwmon: (asc7621) Bug fixes

* Allow fan minimum RPM to be set to zero without triggering alarms.
* Fix voltage scaling arithmetic and correct scale factors.
* Correct fan1-fan4 alarm bit shifts.
* Correct register address for temp3_smoothing_enable.
* Read the alarm registers with high priority.

Signed-off-by: Ken Milmore <ken.milmore@googlemail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 31 insertions, 32 deletions

diff --git a/drivers/hwmon/asc7621.c b/drivers/hwmon/asc7621.c
index 7f948105d8ad..0f388adc6187 100644
--- a/drivers/hwmon/asc7621.c
+++ b/drivers/hwmon/asc7621.c
@@ -268,8 +268,11 @@ static ssize_t store_fan16(struct device *dev,
         if (strict_strtol(buf, 10, &reqval))
                 return -EINVAL;
 
+        /* If a minimum RPM of zero is requested, then we set the register to
+           0xffff. This value allows the fan to be stopped completely without
+           generating an alarm. */
         reqval =
-            (SENSORS_LIMIT((reqval) <= 0 ? 0 : 5400000 / (reqval), 0, 65534));
+            (reqval <= 0 ? 0xffff : SENSORS_LIMIT(5400000 / reqval, 0, 0xfffe));
 
         mutex_lock(&data->update_lock);
         data->reg[param->msb[0]] = (reqval >> 8) & 0xff;
@@ -285,8 +288,9 @@ static ssize_t store_fan16(struct device *dev,
  * Voltages are scaled in the device so that the nominal voltage
  * is 3/4ths of the 0-255 range (i.e. 192).
  * If all voltages are 'normal' then all voltage registers will
- * read 0xC0.  This doesn't help us if we don't have a point of refernce.
- * The data sheet however provides us with the full scale value for each
+ * read 0xC0.
+ *
+ * The data sheet provides us with the 3/4 scale value for each voltage
  * which is stored in in_scaling.  The sda->index parameter value provides
  * the index into in_scaling.
  *
@@ -295,7 +299,7 @@ static ssize_t store_fan16(struct device *dev,
  */
 
 static int asc7621_in_scaling[] = {
-        3320, 3000, 4380, 6640, 16000
+        2500, 2250, 3300, 5000, 12000
 };
 
 static ssize_t show_in10(struct device *dev, struct device_attribute *attr,
@@ -306,19 +310,12 @@ static ssize_t show_in10(struct device *dev, struct device_attribute *attr,
         u8 nr = sda->index;
 
         mutex_lock(&data->update_lock);
-        regval = (data->reg[param->msb[0]] * asc7621_in_scaling[nr]) / 256;
-
-        /* The LSB value is a 2-bit scaling of the MSB's LSbit value.
-         * I.E.  If the maximim voltage for this input is 6640 millivolts then
-         * a MSB register value of 0 = 0mv and 255 = 6640mv.
-         * A 1 step change therefore represents 25.9mv (6640 / 256).
-         * The extra 2-bits therefore represent increments of 6.48mv.
-         */
-        regval += ((asc7621_in_scaling[nr] / 256) / 4) *
-            (data->reg[param->lsb[0]] >> 6);
-
+        regval = (data->reg[param->msb[0]] << 8) | (data->reg[param->lsb[0]]);
         mutex_unlock(&data->update_lock);
 
+        /* The LSB value is a 2-bit scaling of the MSB's LSbit value. */
+        regval = (regval >> 6) * asc7621_in_scaling[nr] / (0xc0 << 2);
+
         return sprintf(buf, "%u\n", regval);
 }
 
@@ -331,7 +328,7 @@ static ssize_t show_in8(struct device *dev, struct device_attribute *attr,
 
         return sprintf(buf, "%u\n",
                        ((data->reg[param->msb[0]] *
-                         asc7621_in_scaling[nr]) / 256));
+                         asc7621_in_scaling[nr]) / 0xc0));
 }
 
 static ssize_t store_in8(struct device *dev, struct device_attribute *attr,
@@ -344,9 +341,11 @@ static ssize_t store_in8(struct device *dev, struct device_attribute *attr,
         if (strict_strtol(buf, 10, &reqval))
                 return -EINVAL;
 
-        reqval = SENSORS_LIMIT(reqval, 0, asc7621_in_scaling[nr]);
+        reqval = SENSORS_LIMIT(reqval, 0, 0xffff);
+
+        reqval = reqval * 0xc0 / asc7621_in_scaling[nr];
 
-        reqval = (reqval * 255 + 128) / asc7621_in_scaling[nr];
+        reqval = SENSORS_LIMIT(reqval, 0, 0xff);
 
         mutex_lock(&data->update_lock);
         data->reg[param->msb[0]] = reqval;
@@ -846,11 +845,11 @@ static struct asc7621_param asc7621_params[] = {
         PWRITE(in3_max, 3, PRI_LOW, 0x4b, 0, 0, 0, in8),
         PWRITE(in4_max, 4, PRI_LOW, 0x4d, 0, 0, 0, in8),
 
-        PREAD(in0_alarm, 0, PRI_LOW, 0x41, 0, 0x01, 0, bitmask),
-        PREAD(in1_alarm, 1, PRI_LOW, 0x41, 0, 0x01, 1, bitmask),
-        PREAD(in2_alarm, 2, PRI_LOW, 0x41, 0, 0x01, 2, bitmask),
-        PREAD(in3_alarm, 3, PRI_LOW, 0x41, 0, 0x01, 3, bitmask),
-        PREAD(in4_alarm, 4, PRI_LOW, 0x42, 0, 0x01, 0, bitmask),
+        PREAD(in0_alarm, 0, PRI_HIGH, 0x41, 0, 0x01, 0, bitmask),
+        PREAD(in1_alarm, 1, PRI_HIGH, 0x41, 0, 0x01, 1, bitmask),
+        PREAD(in2_alarm, 2, PRI_HIGH, 0x41, 0, 0x01, 2, bitmask),
+        PREAD(in3_alarm, 3, PRI_HIGH, 0x41, 0, 0x01, 3, bitmask),
+        PREAD(in4_alarm, 4, PRI_HIGH, 0x42, 0, 0x01, 0, bitmask),
 
         PREAD(fan1_input, 0, PRI_HIGH, 0x29, 0x28, 0, 0, fan16),
         PREAD(fan2_input, 1, PRI_HIGH, 0x2b, 0x2a, 0, 0, fan16),
@@ -862,10 +861,10 @@ static struct asc7621_param asc7621_params[] = {
         PWRITE(fan3_min, 2, PRI_LOW, 0x59, 0x58, 0, 0, fan16),
         PWRITE(fan4_min, 3, PRI_LOW, 0x5b, 0x5a, 0, 0, fan16),
 
-        PREAD(fan1_alarm, 0, PRI_LOW, 0x42, 0, 0x01, 0, bitmask),
-        PREAD(fan2_alarm, 1, PRI_LOW, 0x42, 0, 0x01, 1, bitmask),
-        PREAD(fan3_alarm, 2, PRI_LOW, 0x42, 0, 0x01, 2, bitmask),
-        PREAD(fan4_alarm, 3, PRI_LOW, 0x42, 0, 0x01, 3, bitmask),
+        PREAD(fan1_alarm, 0, PRI_HIGH, 0x42, 0, 0x01, 2, bitmask),
+        PREAD(fan2_alarm, 1, PRI_HIGH, 0x42, 0, 0x01, 3, bitmask),
+        PREAD(fan3_alarm, 2, PRI_HIGH, 0x42, 0, 0x01, 4, bitmask),
+        PREAD(fan4_alarm, 3, PRI_HIGH, 0x42, 0, 0x01, 5, bitmask),
 
         PREAD(temp1_input, 0, PRI_HIGH, 0x25, 0x10, 0, 0, temp10),
         PREAD(temp2_input, 1, PRI_HIGH, 0x26, 0x15, 0, 0, temp10),
@@ -886,10 +885,10 @@ static struct asc7621_param asc7621_params[] = {
         PWRITE(temp3_max, 2, PRI_LOW, 0x53, 0, 0, 0, temp8),
         PWRITE(temp4_max, 3, PRI_LOW, 0x35, 0, 0, 0, temp8),
 
-        PREAD(temp1_alarm, 0, PRI_LOW, 0x41, 0, 0x01, 4, bitmask),
-        PREAD(temp2_alarm, 1, PRI_LOW, 0x41, 0, 0x01, 5, bitmask),
-        PREAD(temp3_alarm, 2, PRI_LOW, 0x41, 0, 0x01, 6, bitmask),
-        PREAD(temp4_alarm, 3, PRI_LOW, 0x43, 0, 0x01, 0, bitmask),
+        PREAD(temp1_alarm, 0, PRI_HIGH, 0x41, 0, 0x01, 4, bitmask),
+        PREAD(temp2_alarm, 1, PRI_HIGH, 0x41, 0, 0x01, 5, bitmask),
+        PREAD(temp3_alarm, 2, PRI_HIGH, 0x41, 0, 0x01, 6, bitmask),
+        PREAD(temp4_alarm, 3, PRI_HIGH, 0x43, 0, 0x01, 0, bitmask),
 
         PWRITE(temp1_source, 0, PRI_LOW, 0x02, 0, 0x07, 4, bitmask),
         PWRITE(temp2_source, 1, PRI_LOW, 0x02, 0, 0x07, 0, bitmask),
@@ -898,7 +897,7 @@ static struct asc7621_param asc7621_params[] = {
 
         PWRITE(temp1_smoothing_enable, 0, PRI_LOW, 0x62, 0, 0x01, 3, bitmask),
         PWRITE(temp2_smoothing_enable, 1, PRI_LOW, 0x63, 0, 0x01, 7, bitmask),
-        PWRITE(temp3_smoothing_enable, 2, PRI_LOW, 0x64, 0, 0x01, 3, bitmask),
+        PWRITE(temp3_smoothing_enable, 2, PRI_LOW, 0x63, 0, 0x01, 3, bitmask),
         PWRITE(temp4_smoothing_enable, 3, PRI_LOW, 0x3c, 0, 0x01, 3, bitmask),
 
         PWRITE(temp1_smoothing_time, 0, PRI_LOW, 0x62, 0, 0x07, 0, temp_st),