hwmon: lochnagar: Add Lochnagar 2 hardware monitoring driver

Lochnagar is an evaluation and development board for Cirrus
Logic Smart CODEC and Amp devices. It allows the connection of
most Cirrus Logic devices on mini-cards, as well as allowing
connection of various application processor systems to provide a
full evaluation platform.

This driver adds support for the hardware monitoring features of
the Lochnagar 2 to the hwmon API. Monitoring is provided for
the board voltages, currents and temperature supported by the
board controller chip.
Signed-off-by: Lucas Tanure <tanureal@opensource.cirrus.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/lochnagar

+Kernel Driver Lochnagar
+========================
+
+Supported systems:
+  * Cirrus Logic : Lochnagar 2
+
+Author: Lucas A. Tanure Alves
+
+Description
+-----------
+
+Lochnagar 2 features built-in Current Monitor circuitry that allows for the
+measurement of both voltage and current on up to eight of the supply voltage
+rails provided to the minicards. The Current Monitor does not require any
+hardware modifications or external circuitry to operate.
+
+The current and voltage measurements are obtained through the standard register
+map interface to the Lochnagar board controller, and can therefore be monitored
+by software.
+
+Sysfs attributes
+----------------
+
+temp1_input             The Lochnagar board temperature (milliCelsius)
+in0_input               Measured voltage for DBVDD1 (milliVolts)
+in0_label               "DBVDD1"
+curr1_input             Measured current for DBVDD1 (milliAmps)
+curr1_label             "DBVDD1"
+power1_average          Measured average power for DBVDD1 (microWatts)
+power1_average_interval Power averaging time input valid from 1 to 1708mS
+power1_label            "DBVDD1"
+in1_input               Measured voltage for 1V8 DSP (milliVolts)
+in1_label               "1V8 DSP"
+curr2_input             Measured current for 1V8 DSP (milliAmps)
+curr2_label             "1V8 DSP"
+power2_average          Measured average power for 1V8 DSP (microWatts)
+power2_average_interval Power averaging time input valid from 1 to 1708mS
+power2_label            "1V8 DSP"
+in2_input               Measured voltage for 1V8 CDC (milliVolts)
+in2_label               "1V8 CDC"
+curr3_input             Measured current for 1V8 CDC (milliAmps)
+curr3_label             "1V8 CDC"
+power3_average          Measured average power for 1V8 CDC (microWatts)
+power3_average_interval Power averaging time input valid from 1 to 1708mS
+power3_label            "1V8 CDC"
+in3_input               Measured voltage for VDDCORE DSP (milliVolts)
+in3_label               "VDDCORE DSP"
+curr4_input             Measured current for VDDCORE DSP (milliAmps)
+curr4_label             "VDDCORE DSP"
+power4_average          Measured average power for VDDCORE DSP (microWatts)
+power4_average_interval Power averaging time input valid from 1 to 1708mS
+power4_label            "VDDCORE DSP"
+in4_input               Measured voltage for AVDD 1V8 (milliVolts)
+in4_label               "AVDD 1V8"
+curr5_input             Measured current for AVDD 1V8 (milliAmps)
+curr5_label             "AVDD 1V8"
+power5_average          Measured average power for AVDD 1V8 (microWatts)
+power5_average_interval Power averaging time input valid from 1 to 1708mS
+power5_label            "AVDD 1V8"
+curr6_input             Measured current for SYSVDD (milliAmps)
+curr6_label             "SYSVDD"
+power6_average          Measured average power for SYSVDD (microWatts)
+power6_average_interval Power averaging time input valid from 1 to 1708mS
+power6_label            "SYSVDD"
+in6_input               Measured voltage for VDDCORE CDC (milliVolts)
+in6_label               "VDDCORE CDC"
+curr7_input             Measured current for VDDCORE CDC (milliAmps)
+curr7_label             "VDDCORE CDC"
+power7_average          Measured average power for VDDCORE CDC (microWatts)
+power7_average_interval Power averaging time input valid from 1 to 1708mS
+power7_label            "VDDCORE CDC"
+in7_input               Measured voltage for MICVDD (milliVolts)
+in7_label               "MICVDD"
+curr8_input             Measured current for MICVDD (milliAmps)
+curr8_label             "MICVDD"
+power8_average          Measured average power for MICVDD (microWatts)
+power8_average_interval Power averaging time input valid from 1 to 1708mS
+power8_label            "MICVDD"
+
+Note: It is not possible to measure voltage on the SYSVDD rail.

MAINTAINERS

@@ -3797,6 +3797,7 @@ M:	Richard Fitzgerald <rf@opensource.cirrus.com>
 L:	patches@opensource.cirrus.com
 S:	Supported
 F:	drivers/clk/clk-lochnagar.c
+F:	drivers/hwmon/lochnagar-hwmon.c
 F:	drivers/mfd/lochnagar-i2c.c
 F:	drivers/pinctrl/cirrus/pinctrl-lochnagar.c
 F:	drivers/regulator/lochnagar-regulator.c
@@ -3805,8 +3806,10 @@ F:	include/dt-bindings/pinctrl/lochnagar.h
 F:	include/linux/mfd/lochnagar*
 F:	Documentation/devicetree/bindings/mfd/cirrus,lochnagar.txt
 F:	Documentation/devicetree/bindings/clock/cirrus,lochnagar.txt
+F:	Documentation/devicetree/bindings/hwmon/cirrus,lochnagar.txt
 F:	Documentation/devicetree/bindings/pinctrl/cirrus,lochnagar.txt
 F:	Documentation/devicetree/bindings/regulator/cirrus,lochnagar.txt
+F:	Documentation/hwmon/lochnagar
 
 CISCO FCOE HBA DRIVER
 M:	Satish Kharat <satishkh@cisco.com>

drivers/hwmon/Kconfig

@@ -705,6 +705,16 @@ config SENSORS_LINEAGE
 	  This driver can also be built as a module. If so, the module
 	  will be called lineage-pem.
 
+config SENSORS_LOCHNAGAR
+	tristate "Lochnagar Hardware Monitor"
+	depends on MFD_LOCHNAGAR
+	help
+	  If you say yes here you get support for Lochnagar 2 temperature,
+	  voltage and current sensors abilities.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called lochnagar-hwmon.
+
 config SENSORS_LTC2945
 	tristate "Linear Technology LTC2945"
 	depends on I2C

drivers/hwmon/Makefile

@@ -89,6 +89,7 @@ obj-$(CONFIG_SENSORS_JZ4740)	+= jz4740-hwmon.o
 obj-$(CONFIG_SENSORS_K8TEMP)	+= k8temp.o
 obj-$(CONFIG_SENSORS_K10TEMP)	+= k10temp.o
 obj-$(CONFIG_SENSORS_LINEAGE)	+= lineage-pem.o
+obj-$(CONFIG_SENSORS_LOCHNAGAR)	+= lochnagar-hwmon.o
 obj-$(CONFIG_SENSORS_LM63)	+= lm63.o
 obj-$(CONFIG_SENSORS_LM70)	+= lm70.o
 obj-$(CONFIG_SENSORS_LM73)	+= lm73.o