hwmon: (pmbus) Driver for Delta power supplies Q54SJ108A2

The driver supports Q54SJ108A2 series modules of Delta.
Standard attributes are in sysfs, and other attributes are in debugfs.

Signed-off-by: xiao.ma <xiao.mx.ma@deltaww.com>
Link: https://lore.kernel.org/r/20201202025900.1842-1-max701@126.com
[groeck: Replaced spaces with tabs, dropped excessive spaces,
 fixed module prefix in documentation]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/index.rst

@@ -151,6 +151,7 @@ Hardware Monitoring Kernel Drivers
    powr1220
    pxe1610
    pwm-fan
+   q54sj108a2
    raspberrypi-hwmon
    sch5627
    sch5636

Documentation/hwmon/q54sj108a2.rst

@@ -0,0 +1,54 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver q54sj108a2
+=====================
+
+Supported chips:
+
+  * DELTA Q54SJ108A2NCAH, Q54SJ108A2NCDH, Q54SJ108A2NCPG, Q54SJ108A2NCPH
+
+    Prefix: 'q54sj108a2'
+
+    Addresses scanned: -
+
+    Datasheet: https://filecenter.delta-china.com.cn/products/download/01/0102/datasheet/DS_Q54SJ108A2.pdf
+
+Authors:
+    Xiao.ma <xiao.mx.ma@deltaww.com>
+
+
+Description
+-----------
+
+This driver implements support for DELTA Q54SJ108A2NCAH, Q54SJ108A2NCDH,
+Q54SJ108A2NCPG, and Q54SJ108A2NCPH 1/4 Brick DC/DC Regulated Power Module
+with PMBus support.
+
+The driver is a client driver to the core PMBus driver.
+Please see Documentation/hwmon/pmbus.rst for details on PMBus client drivers.
+
+
+Usage Notes
+-----------
+
+This driver does not auto-detect devices. You will have to instantiate the
+devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
+details.
+
+
+Sysfs entries
+-------------
+
+===================== ===== ==================================================
+curr1_alarm           RO    Output current alarm
+curr1_input           RO    Output current
+curr1_label           RO    'iout1'
+in1_alarm             RO    Input voltage alarm
+in1_input             RO    Input voltage
+in1_label             RO    'vin'
+in2_alarm             RO    Output voltage alarm
+in2_input             RO    Output voltage
+in2_label             RO    'vout1'
+temp1_alarm           RO    Temperature alarm
+temp1_input           RO    Chip temperature
+===================== ===== ==================================================

drivers/hwmon/pmbus/Kconfig

@@ -238,6 +238,15 @@ config SENSORS_PXE1610
 	  This driver can also be built as a module. If so, the module will
 	  be called pxe1610.
 
+config SENSORS_Q54SJ108A2
+	tristate "Delta Power Supplies Q54SJ108A2"
+	help
+	  If you say yes here you get hardware monitoring support for Delta
+	  Q54SJ108A2 series Power Supplies.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called q54sj108a2.
+
 config SENSORS_TPS40422
 	tristate "TI TPS40422"
 	help

drivers/hwmon/pmbus/Makefile

@@ -27,6 +27,7 @@ obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o
 obj-$(CONFIG_SENSORS_MP2975)	+= mp2975.o
 obj-$(CONFIG_SENSORS_PM6764TR)	+= pm6764tr.o
 obj-$(CONFIG_SENSORS_PXE1610)	+= pxe1610.o
+obj-$(CONFIG_SENSORS_Q54SJ108A2)	+= q54sj108a2.o
 obj-$(CONFIG_SENSORS_TPS40422)	+= tps40422.o
 obj-$(CONFIG_SENSORS_TPS53679)	+= tps53679.o
 obj-$(CONFIG_SENSORS_UCD9000)	+= ucd9000.o