hwmon: (pmbus) Add support for MPS mp2975 controller

The patchset includes:
Patch #1 - introduction of the driver for mp2975 device,
documentation for mp2975 device driver.
Patch #2 - extending of binding documentation for trivial devices.

Vadim Pasternak (2):
hwmon: (pmbus) Add support for MPS Multi-phase mp2975 controller
dt-bindings: Add MP2975 voltage regulator device

 .../devicetree/bindings/trivial-devices.yaml       |   2 +
 Documentation/hwmon/mp2975.rst                     | 116 +++
 drivers/hwmon/pmbus/Kconfig                        |   9 +
 drivers/hwmon/pmbus/Makefile                       |   1 +
 drivers/hwmon/pmbus/mp2975.c                       | 812 +++++++++++++++++++++
 5 files changed, 940 insertions(+)
 create mode 100644 Documentation/hwmon/mp2975.rst
 create mode 100644 drivers/hwmon/pmbus/mp2975.c

2.11.0

Add support for mp295 device from Monolithic Power Systems, Inc. (MPS) vendor. This is a dual-loop, digital, multi-phase controller. This device:
- Supports two power rail.
- Provides 8 pulse-width modulations (PWMs), and can be configured up to 8-phase operation for rail 1 and up to 4-phase operation for rail 2.
- Supports two pages 0 and 1 for telemetry and also pages 2 and 3 for configuration.
- Can configured VOUT readout in direct or VID format and allows setting of different formats on rails 1 and 2. For VID the following protocols are available: VR13 mode with 5-mV DAC; VR13 mode with 10-mV DAC, IMVP9 mode with 5-mV DAC.

---
v1->v2
Comments pointed out by Guenter:
- Add doc fail to the patch#1 (it was sent as separate patch).
- Use standard define for VOUT mode format.
- Simplify logic in mp2975_read_phase().
- Simplify calculation of phase current in mp2975_read_phase().
- Modify return code handling in mp2975_read_word_data().
- Add missed error handling in mp2975_read_word_data().
- Drop 'fallthrough;' in mp2975_read_word_data().
- Handle error code in mp2975_identify_multiphase_rail2().
- Handle error code in mp2975_identify_multiphase().
- Drop 'goto' in mp2975_vout_per_rail_config_get() and mp2975_probe().

---
 Documentation/hwmon/mp2975.rst | 116 ++++++
 drivers/hwmon/pmbus/Kconfig    |   9 +
 drivers/hwmon/pmbus/Makefile   |   1 +
 drivers/hwmon/pmbus/mp2975.c   | 812 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 938 insertions(+)
 create mode 100644 Documentation/hwmon/mp2975.rst
 create mode 100644 drivers/hwmon/pmbus/mp2975.c

new file mode 100644
index 000000000000..5b0609c62f48
@@ -0,0 +1,116 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver mp2975
+====================
+
+Supported chips:
+
+  * MPS MP12254
+
+    Prefix: 'mp2975'
+
+Author:
+
+	Vadim Pasternak <[email protected]>
+
+Description
+-----------
+
+This driver implements support for Monolithic Power Systems, Inc. (MPS)
+vendor dual-loop, digital, multi-phase controller MP2975.
+
+This device:
+- Supports up to two power rail.
+- Provides 8 pulse-width modulations (PWMs), and can be configured up
+  to 8-phase operation for rail 1 and up to 4-phase operation for rail
+  2.
+- Supports two pages 0 and 1 for telemetry and also pages 2 and 3 for
+  configuration.
+- Can configured VOUT readout in direct or VID format and allows
+  setting of different formats on rails 1 and 2. For VID the following
+  protocols are available: VR13 mode with 5-mV DAC; VR13 mode with
+  10-mV DAC, IMVP9 mode with 5-mV DAC.
+
+Device supports:
+- SVID interface.
+- AVSBus interface.
+
+Device complaint with:
+- PMBus rev 1.3 interface.
+
+Device supports direct format for reading output current, output voltage,
+input and output power and temperature.
+Device supports linear format for reading input voltage and input power.
+Device supports VID and direct formats for reading output voltage.
+The below VID modes are supported: VR12, VR13, IMVP9.
+
+The driver provides the next attributes for the current:
+- for current in: input, maximum alarm;
+- for current out input, maximum alarm and highest values;
+- for phase current: input and label.
+attributes.
+The driver exports the following attributes via the 'sysfs' files, where
+- 'n' is number of telemetry pages (from 1 to 2);
+- 'k' is number of configured phases (from 1 to 8);
+- indexes 1, 1*n for "iin";
+- indexes n+1, n+2 for "iout";
+- indexes 2*n+1 ... 2*n + k for phases.
+
+**curr[1-{2n}]_alarm**
+
+**curr[{n+1}-{n+2}]_highest**
+
+**curr[1-{2n+k}]_input**
+
+**curr[1-{2n+k}]_label**
+
+The driver provides the next attributes for the voltage:
+- for voltage in: input, high critical threshold, high critical alarm, all only
+  from page 0;
+- for voltage out: input, low and high critical thresholds, low and high
+  critical alarms, from pages 0 and 1;
+The driver exports the following attributes via the 'sysfs' files, where
+- 'n' is number of telemetry pages (from 1 to 2);
+- indexes 1 for "iin";
+- indexes n+1, n+2 for "vout";
+
+**in[1-{2n+1}]_crit**
+
+**in[1-{2n+1}]_crit_alarm**
+
+**in[1-{2n+1}]_input**
+
+**in[1-{2n+1}]_label**
+
+**in[2-{n+1}]_lcrit**
+
+**in[2-{n+1}1_lcrit_alarm**
+
+The driver provides the next attributes for the power:
+- for power in alarm and input.
+- for power out: highest and input.
+The driver exports the following attributes via the 'sysfs' files, where
+- 'n' is number of telemetry pages (from 1 to 2);
+- indexes 1 for "pin";
+- indexes n+1, n+2 for "pout";
+
+**power1_alarm**
+
+**power[2-{n+1}]_highest**
+
+**power[1-{2n+1}]_input**
+
+**power[1-{2n+1}]_label**
+
+The driver provides the next attributes for the temperature (only from page 0):
+
+
+**temp1_crit**
+
+**temp1_crit_alarm**
+
+**temp1_input**
+
+**temp1_max**
+
+**temp1_max_alarm**

index e35db489b76f..1e6157e85437 100644
@@ -200,6 +200,15 @@ config SENSORS_MAX8688
 	  This driver can also be built as a module. If so, the module will
 	  be called max8688.
 
+config SENSORS_MP2975
+	tristate "MPS MP2975"
+	help
+	  If you say yes here you get hardware monitoring support for MPS
+	  MP2975 Dual Loop Digital Multi-Phase Controller.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called mp2975.
+
 config SENSORS_PXE1610
 	tristate "Infineon PXE1610"
 	help

index c4b15db996ad..0e2832e73cfc 100644
@@ -23,6 +23,7 @@ obj-$(CONFIG_SENSORS_MAX20751)	+= max20751.o
 obj-$(CONFIG_SENSORS_MAX31785)	+= max31785.o
 obj-$(CONFIG_SENSORS_MAX34440)	+= max34440.o
 obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o
+obj-$(CONFIG_SENSORS_MP2975)	+= mp2975.o
 obj-$(CONFIG_SENSORS_PXE1610)	+= pxe1610.o
 obj-$(CONFIG_SENSORS_TPS40422)	+= tps40422.o
 obj-$(CONFIG_SENSORS_TPS53679)	+= tps53679.o

2.11.0

Monolithic Power Systems, Inc. (MPS) dual-loop, digital, multi-phase controller.

---
 Documentation/devicetree/bindings/trivial-devices.yaml | 2 ++
 1 file changed, 2 insertions(+)

index 4ace8039840a..697211c7622f 100644
@@ -80,6 +80,8 @@ properties:
           - fsl,mpl3115
             # MPR121: Proximity Capacitive Touch Sensor Controller
           - fsl,mpr121
+	    # Monolithic Power Systems, Inc. multi-phase controller mp2975
+	  - mps,mp2975
             # G751: Digital Temperature Sensor and Thermal Watchdog with Two-Wire Interface
           - gmt,g751
             # Infineon IR38064 Voltage Regulator

2.11.0

My bot found errors running 'make dt_binding_check' on your patch:

Traceback (most recent call last):
File "/usr/local/bin/dt-extract-example", line 45, in <module>
binding = yaml.load(open(args.yamlfile, encoding='utf-8').read())
File "/usr/local/lib/python3.8/dist-packages/ruamel/yaml/main.py", line 343, in load
return constructor.get_single_data()
File "/usr/local/lib/python3.8/dist-packages/ruamel/yaml/constructor.py", line 111, in get_single_data
node = self.composer.get_single_node()
File "_ruamel_yaml.pyx", line 706, in _ruamel_yaml.CParser.get_single_node
File "_ruamel_yaml.pyx", line 724, in _ruamel_yaml.CParser._compose_document
File "_ruamel_yaml.pyx", line 775, in _ruamel_yaml.CParser._compose_node
File "_ruamel_yaml.pyx", line 889, in _ruamel_yaml.CParser._compose_mapping_node
File "_ruamel_yaml.pyx", line 775, in _ruamel_yaml.CParser._compose_node
File "_ruamel_yaml.pyx", line 889, in _ruamel_yaml.CParser._compose_mapping_node
File "_ruamel_yaml.pyx", line 775, in _ruamel_yaml.CParser._compose_node
File "_ruamel_yaml.pyx", line 889, in _ruamel_yaml.CParser._compose_mapping_node
File "_ruamel_yaml.pyx", line 773, in _ruamel_yaml.CParser._compose_node
File "_ruamel_yaml.pyx", line 850, in _ruamel_yaml.CParser._compose_sequence_node
File "_ruamel_yaml.pyx", line 775, in _ruamel_yaml.CParser._compose_node
File "_ruamel_yaml.pyx", line 889, in _ruamel_yaml.CParser._compose_mapping_node
File "_ruamel_yaml.pyx", line 773, in _ruamel_yaml.CParser._compose_node
File "_ruamel_yaml.pyx", line 852, in _ruamel_yaml.CParser._compose_sequence_node
File "_ruamel_yaml.pyx", line 904, in _ruamel_yaml.CParser._parse_next_event
ruamel.yaml.scanner.ScannerError: while scanning a plain scalar
in "<unicode string>", line 82, column 13
found a tab character that violates indentation
in "<unicode string>", line 83, column 1
make[1]: *** [Documentation/devicetree/bindings/Makefile:18: Documentation/devicetree/bindings/trivial-devices.example.dts] Error 1 make[1]: *** Deleting file 'Documentation/devicetree/bindings/trivial-devices.example.dts'
make[1]: *** Waiting for unfinished jobs....
./Documentation/devicetree/bindings/trivial-devices.yaml: while scanning a plain scalar
in "<unicode string>", line 82, column 13
found a tab character that violates indentation
in "<unicode string>", line 83, column 1
/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/trivial-devices.yaml: ignoring, error parsing file
warning: no schema found in file: ./Documentation/devicetree/bindings/trivial-devices.yaml
make: *** [Makefile:1366: dt_binding_check] Error 2

See https://patchwork.ozlabs.org/patch/1369246

If you already ran 'make dt_binding_check' and didn't see the above error(s), then make sure dt-schema is up to date:

pip3 install git+https://github.com/devicetree-org/dt-schema.git@master --upgrade

Please check and re-submit.