hwmon: Add driver for Texas Instruments TMP464 and TMP468

Add support for Texas Instruments TMP464 and TMP468 temperature sensor
ICs.

TI's TMP464 is an I2C temperature sensor chip. This chip is similar
to TI's TMP421 chip, but with 16bit-wide registers (instead of
8bit-wide registers). The chip has one local sensor and four remote
sensors. TMP468 is similar to TMP464 but has one local and eight
remote sensors.

Originally-from: Agathe Porte <agathe.porte@nokia.com>
Cc: Agathe Porte <agathe.porte@nokia.com>
Cc: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Tested-by: Agathe Porte <agathe.porte@nokia.com>
Link: https://lore.kernel.org/r/20220222223610.23098-2-linux@roeck-us.net
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 73 insertions, 0 deletions

diff --git a/Documentation/hwmon/tmp464.rst b/Documentation/hwmon/tmp464.rst
new file mode 100644
index 000000000000..7596e7623d06
--- /dev/null
+++ b/Documentation/hwmon/tmp464.rst
@@ -0,0 +1,73 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver tmp464
+====================
+
+Supported chips:
+
+  * Texas Instruments TMP464
+
+    Prefix: 'tmp464'
+
+    Addresses scanned: I2C 0x48, 0x49, 0x4a and 0x4b
+
+    Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp464.html
+
+  * Texas Instruments TMP468
+
+    Prefix: 'tmp468'
+
+    Addresses scanned: I2C 0x48, 0x49, 0x4a and 0x4b
+
+    Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp468.html
+
+Authors:
+
+	Agathe Porte <agathe.porte@nokia.com>
+	Guenter Roeck <linux@roeck-us.net>
+
+Description
+-----------
+
+This driver implements support for Texas Instruments TMP464 and TMP468
+temperature sensor chips. TMP464 provides one local and four remote
+sensors. TMP468 provides one local and eight remote sensors.
+Temperature is measured in degrees Celsius. The chips are wired over
+I2C/SMBus and specified over a temperature range of -40 to +125 degrees
+Celsius. Resolution for both the local and remote channels is 0.0625
+degree C.
+
+The chips support only temperature measurements. The driver exports
+temperature values, limits, and alarms via the following sysfs files:
+
+**temp[1-9]_input**
+
+**temp[1-9]_max**
+
+**temp[1-9]_max_hyst**
+
+**temp[1-9]_max_alarm**
+
+**temp[1-9]_crit**
+
+**temp[1-9]_crit_alarm**
+
+**temp[1-9]_crit_hyst**
+
+**temp[2-9]_offset**
+
+**temp[2-9]_fault**
+
+Each sensor can be individually disabled via Devicetree or from sysfs
+via:
+
+**temp[1-9]_enable**
+
+If labels were specified in Devicetree, additional sysfs files will
+be present:
+
+**temp[1-9]_label**
+
+The update interval is configurable with the following sysfs attribute.
+
+**update_interval**