MAX6690 is all but identical to MAX6654. Revision 1 of its
datasheet lists the same chip ID as MAX6654, and a chip labeled
MAX6654 was found to have the chip ID listed as MAX6690 chip ID
in Revision 2 of its datasheet.
A devicetree node is not added for this chip since it is quite unlikely
that such an old chip will ever be used in a devicetree based system.
It can be added later if needed.
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
Documentation/hwmon/lm90.rst | 2 +-
drivers/hwmon/lm90.c | 17 ++++++++++++++++-
2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/Documentation/hwmon/lm90.rst b/Documentation/hwmon/lm90.rst
index 53429f79b819..45bc333a1219 100644
--- a/Documentation/hwmon/lm90.rst
+++ b/Documentation/hwmon/lm90.rst
@@ -370,7 +370,7 @@ MAX6648, MAX6692:
* Better local resolution
* Unsigned temperature
-MAX6654:
+MAX6654, MAX6690:
* Better local resolution
* Selectable address
* Remote sensor type selection
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index abc64738e892..22ea75535ab4 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -42,7 +42,8 @@
* accordingly, and is done during initialization. Extended precision is only
* available at conversion rates of 1 Hz and slower. Note that extended
* precision is not enabled by default, as this driver initializes all chips
- * to 2 Hz by design.
+ * to 2 Hz by design. The driver also supports MAX6690, which is practically
+ * identical to MAX6654.
*
* This driver also supports the MAX6646, MAX6647, MAX6648, MAX6649 and
* MAX6692 chips made by Maxim. These are again similar to the LM86,
@@ -237,6 +238,7 @@ static const struct i2c_device_id lm90_id[] = {
{ "max6659", max6659 },
{ "max6680", max6680 },
{ "max6681", max6680 },
+ { "max6690", max6654 },
{ "max6692", max6648 },
{ "max6695", max6696 },
{ "max6696", max6696 },
@@ -1716,6 +1718,19 @@ static const char *lm90_detect_maxim(struct i2c_client *client, int chip_id,
if (!(config1 & 0x07) && convrate <= 0x07)
name = "max6654";
break;
+ case 0x09:
+ /*
+ * The chip_id of the MAX6690 holds the revision of the chip.
+ * The lowest 3 bits of the config1 register are unused and
+ * should return zero when read.
+ * Note that MAX6654 and MAX6690 are practically the same chips.
+ * The only diference is the rated accuracy. Rev. 1 of the
+ * MAX6690 datasheet lists a chip ID of 0x08, and a chip labeled
+ * MAX6654 was observed to have a chip ID of 0x09.
+ */
+ if (!(config1 & 0x07) && convrate <= 0x07)
+ name = "max6690";
+ break;
case 0x4d:
/*
* The MAX6657, MAX6658 and MAX6659 do NOT have a chip_id
--
2.35.1
