hwmon: (lm90) Add support for the LM99 16 degree offset
The LM99 differs from the LM86, LM89 and LM90 in that it reports
remote temperatures (temp2) 16 degrees lower than they really are. So
far we have been cheating and handled this in userspace but it really
should be handled by the driver directly.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index 6242e72..96a7018 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -12,9 +12,9 @@
* made by National Semiconductor. Both have an increased remote
* temperature measurement accuracy (1 degree), and the LM99
* additionally shifts remote temperatures (measured and limits) by 16
- * degrees, which allows for higher temperatures measurement. The
- * driver doesn't handle it since it can be done easily in user-space.
+ * degrees, which allows for higher temperatures measurement.
* Note that there is no way to differentiate between both chips.
+ * When device is auto-detected, the driver will assume an LM99.
*
* This driver also supports the LM86, another sensor chip made by
* National Semiconductor. It is exactly similar to the LM90 except it
@@ -169,8 +169,8 @@
{ "adt7461", adt7461 },
{ "lm90", lm90 },
{ "lm86", lm86 },
- { "lm89", lm99 },
- { "lm99", lm99 }, /* Missing temperature offset */
+ { "lm89", lm86 },
+ { "lm99", lm99 },
{ "max6646", max6646 },
{ "max6647", max6646 },
{ "max6649", max6646 },
@@ -366,6 +366,10 @@
else
temp = temp_from_s8(data->temp8[attr->index]);
+ /* +16 degrees offset for temp2 for the LM99 */
+ if (data->kind == lm99 && attr->index == 3)
+ temp += 16000;
+
return sprintf(buf, "%d\n", temp);
}
@@ -385,6 +389,10 @@
long val = simple_strtol(buf, NULL, 10);
int nr = attr->index;
+ /* +16 degrees offset for temp2 for the LM99 */
+ if (data->kind == lm99 && attr->index == 3)
+ val -= 16000;
+
mutex_lock(&data->update_lock);
if (data->kind == adt7461)
data->temp8[nr] = temp_to_u8_adt7461(data, val);
@@ -411,6 +419,10 @@
else
temp = temp_from_s16(data->temp11[attr->index]);
+ /* +16 degrees offset for temp2 for the LM99 */
+ if (data->kind == lm99 && attr->index <= 2)
+ temp += 16000;
+
return sprintf(buf, "%d\n", temp);
}
@@ -432,6 +444,10 @@
long val = simple_strtol(buf, NULL, 10);
int nr = attr->index;
+ /* +16 degrees offset for temp2 for the LM99 */
+ if (data->kind == lm99 && attr->index <= 2)
+ val -= 16000;
+
mutex_lock(&data->update_lock);
if (data->kind == adt7461)
data->temp11[nr] = temp_to_u16_adt7461(data, val);
@@ -466,6 +482,10 @@
else
temp = temp_from_s8(data->temp8[attr->index]);
+ /* +16 degrees offset for temp2 for the LM99 */
+ if (data->kind == lm99 && attr->index == 3)
+ temp += 16000;
+
return sprintf(buf, "%d\n", temp - temp_from_s8(data->temp_hyst));
}
@@ -691,6 +711,15 @@
} else
if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
kind = lm99;
+ dev_info(&adapter->dev,
+ "Assuming LM99 chip at "
+ "0x%02x\n", address);
+ dev_info(&adapter->dev,
+ "If it is an LM89, pass "
+ "force_lm86=%d,0x%02x when "
+ "loading the lm90 driver\n",
+ i2c_adapter_id(adapter),
+ address);
} else
if (address == 0x4C
&& (chip_id & 0xF0) == 0x10) { /* LM86 */