hwmon: peci: Add dimmtemp driver

Add peci-dimmtemp driver for Temperature Sensor on DIMM readings that
are accessible via the processor PECI interface.

The main use case for the driver (and PECI interface) is out-of-band
management, where we're able to obtain thermal readings from an external
entity connected with PECI, e.g. BMC on server platforms.

Co-developed-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
Link: https://lore.kernel.org/r/20220208153639.255278-12-iwona.winiarska@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwmon/peci/Kconfig

@@ -14,5 +14,18 @@ config SENSORS_PECI_CPUTEMP
 	  This driver can also be built as a module. If so, the module
 	  will be called peci-cputemp.
 
+config SENSORS_PECI_DIMMTEMP
+	tristate "PECI DIMM temperature monitoring client"
+	depends on PECI
+	select SENSORS_PECI
+	select PECI_CPU
+	help
+	  If you say yes here you get support for the generic Intel PECI hwmon
+	  driver which provides Temperature Sensor on DIMM readings that are
+	  accessible via the processor PECI interface.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called peci-dimmtemp.
+
 config SENSORS_PECI
 	tristate

drivers/hwmon/peci/Makefile

@@ -1,5 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
 peci-cputemp-y := cputemp.o
+peci-dimmtemp-y := dimmtemp.o
 
 obj-$(CONFIG_SENSORS_PECI_CPUTEMP)	+= peci-cputemp.o
+obj-$(CONFIG_SENSORS_PECI_DIMMTEMP)	+= peci-dimmtemp.o