hwmon: (lm85) Clean up the handling of additional resolution bits
The way the lm85 driver currently handles the additional resolution
bits some chips have for the voltage and temperature measurements is
quite complex. This is my attempt to make it simpler.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Juerg Haefliger <juergh at gmail.com>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
diff --git a/drivers/hwmon/lm85.c b/drivers/hwmon/lm85.c
index 3b70815..0c61fa3 100644
--- a/drivers/hwmon/lm85.c
+++ b/drivers/hwmon/lm85.c
@@ -139,10 +139,10 @@
#define INS_TO_REG(n,val) \
SENSORS_LIMIT(SCALE(val,lm85_scaling[n],192),0,255)
-#define INSEXT_FROM_REG(n,val,ext,scale) \
- SCALE((val)*(scale) + (ext),192*(scale),lm85_scaling[n])
+#define INSEXT_FROM_REG(n,val,ext) \
+ SCALE(((val) << 4) + (ext), 192 << 4, lm85_scaling[n])
-#define INS_FROM_REG(n,val) INSEXT_FROM_REG(n,val,0,1)
+#define INS_FROM_REG(n,val) SCALE((val), 192, lm85_scaling[n])
/* FAN speed is measured using 90kHz clock */
#define FAN_TO_REG(val) (SENSORS_LIMIT( (val)<=0?0: 5400000/(val),0,65534))
@@ -151,10 +151,9 @@
/* Temperature is reported in .001 degC increments */
#define TEMP_TO_REG(val) \
SENSORS_LIMIT(SCALE(val,1000,1),-127,127)
-#define TEMPEXT_FROM_REG(val,ext,scale) \
- SCALE((val)*scale + (ext),scale,1000)
-#define TEMP_FROM_REG(val) \
- TEMPEXT_FROM_REG(val,0,1)
+#define TEMPEXT_FROM_REG(val,ext) \
+ SCALE(((val) << 4) + (ext), 16, 1000)
+#define TEMP_FROM_REG(val) ((val) * 1000)
#define PWM_TO_REG(val) (SENSORS_LIMIT(val,0,255))
#define PWM_FROM_REG(val) (val)
@@ -334,7 +333,6 @@
u8 tach_mode; /* Register encoding, combined */
u8 temp_ext[3]; /* Decoded values */
u8 in_ext[8]; /* Decoded values */
- u8 adc_scale; /* ADC Extended bits scaling factor */
u8 fan_ppr; /* Register value */
u8 smooth[3]; /* Register encoding */
u8 vid; /* Register value */
@@ -541,8 +539,7 @@
struct lm85_data *data = lm85_update_device(dev);
return sprintf( buf, "%d\n", INSEXT_FROM_REG(nr,
data->in[nr],
- data->in_ext[nr],
- data->adc_scale) );
+ data->in_ext[nr]));
}
static ssize_t show_in_min(struct device *dev, struct device_attribute *attr,
@@ -616,8 +613,7 @@
int nr = to_sensor_dev_attr(attr)->index;
struct lm85_data *data = lm85_update_device(dev);
return sprintf(buf,"%d\n", TEMPEXT_FROM_REG(data->temp[nr],
- data->temp_ext[nr],
- data->adc_scale) );
+ data->temp_ext[nr]));
}
static ssize_t show_temp_min(struct device *dev, struct device_attribute *attr,
@@ -1394,6 +1390,8 @@
/* Have to read extended bits first to "freeze" the
* more significant bits that are read later.
+ * There are 2 additional resolution bits per channel and we
+ * have room for 4, so we shift them to the left.
*/
if ( (data->type == adm1027) || (data->type == adt7463) ) {
int ext1 = lm85_read_value(client,
@@ -1403,18 +1401,12 @@
int val = (ext1 << 8) + ext2;
for(i = 0; i <= 4; i++)
- data->in_ext[i] = (val>>(i * 2))&0x03;
+ data->in_ext[i] = ((val>>(i * 2))&0x03) << 2;
for(i = 0; i <= 2; i++)
- data->temp_ext[i] = (val>>((i + 5) * 2))&0x03;
+ data->temp_ext[i] = (val>>((i + 4) * 2))&0x0c;
}
- /* adc_scale is 2^(number of LSBs). There are 4 extra bits in
- the emc6d102 and 2 in the adt7463 and adm1027. In all
- other chips ext is always 0 and the value of scale is
- irrelevant. So it is left in 4*/
- data->adc_scale = (data->type == emc6d102 ) ? 16 : 4;
-
data->vid = lm85_read_value(client, LM85_REG_VID);
for (i = 0; i <= 3; ++i) {