commit e92aba4516471f5a01d4ab1f93eb9919ec05c21f
author Jagpal Singh Gill <paligill@gmail.com> Thu Oct 16 00:00:13 2025 -0700
committer Jagpal Singh Gill <paligill@gmail.com> Mon Nov 10 15:13:56 2025 -0800
tree bcbd0cd56ade95b40bb7b2776f045ea7e1b11c10
parent 978c7809923b3ef62a39ab404f35093ea39fcdc7

rtu: implement modbus sensor read

Read the modbus device config from the Entity Manager configuration and
create the sensor interfaces for related sensor register config.

Tested:
Added new Unit test named test_sensors -
```
> meson test -t 10 -C builddir/ --print-errorlogs --wrapper="valgrind --error-exitcode=1" test_sensors
ninja: Entering directory `/host/repos/Modbus/phosphor-modbus/builddir'
[2/2] Linking target tests/test_sensors
1/1 test_sensors        OK              13.98s

Ok:                1
Fail:              0
```

Tested on Qemu using Mock Modbus Device -
```
root@ventura:~# busctl tree xyz.openbmc_project.ModbusRTU
└─ /xyz
  └─ /xyz/openbmc_project
    ├─ /xyz/openbmc_project/inventory_source
    │ ├─ /xyz/openbmc_project/inventory_source/Heat_Exchanger_12_DevTTYUSB0
    │ ├─ /xyz/openbmc_project/inventory_source/Heat_Exchanger_12_DevTTYUSB1
    │ ├─ /xyz/openbmc_project/inventory_source/Reservoir_Pumping_Unit_12_DevTTYUSB0
    │ └─ /xyz/openbmc_project/inventory_source/Reservoir_Pumping_Unit_12_DevTTYUSB1
    └─ /xyz/openbmc_project/sensors
      └─ /xyz/openbmc_project/sensors/temperature
        ├─ /xyz/openbmc_project/sensors/temperature/Reservoir_Pumping_Unit_12_DevTTYUSB0_RPU_Coolant_Inlet_Temp_C
        ├─ /xyz/openbmc_project/sensors/temperature/Reservoir_Pumping_Unit_12_DevTTYUSB0_RPU_Coolant_Outlet_Temp_C
        ├─ /xyz/openbmc_project/sensors/temperature/Reservoir_Pumping_Unit_12_DevTTYUSB1_RPU_Coolant_Inlet_Temp_C
        └─ /xyz/openbmc_project/sensors/temperature/Reservoir_Pumping_Unit_12_DevTTYUSB1_RPU_Coolant_Outlet_Temp_C

busctl introspect xyz.openbmc_project.ModbusRTU /xyz/openbmc_project/sensors/temperature/Reservoir_Pumping_Unit_12_DevTTYUSB1_RPU_Coolant_Outlet_Temp_C
NAME                                TYPE      SIGNATURE RESULT/VALUE                             FLAGS
org.freedesktop.DBus.Introspectable interface -         -                                        -
.Introspect                         method    -         s                                        -
org.freedesktop.DBus.Peer           interface -         -                                        -
.GetMachineId                       method    -         s                                        -
.Ping                               method    -         -                                        -
org.freedesktop.DBus.Properties     interface -         -                                        -
.Get                                method    ss        v                                        -
.GetAll                             method    s         a{sv}                                    -
.Set                                method    ssv       -                                        -
.PropertiesChanged                  signal    sa{sv}as  -                                        -
xyz.openbmc_project.Sensor.Value    interface -         -                                        -
.MaxValue                           property  d         nan                                      emits-change writable
.MinValue                           property  d         nan                                      emits-change writable
.Unit                               property  s         "xyz.openbmc_project.Sensor.Value.Unit.… emits-change writable
.Value                              property  d         1670.6                                   emits-change writable
```

Change-Id: I1368e8df5999b5cee9ac19d185ee110a9ecc3021
Signed-off-by: Jagpal Singh Gill <paligill@gmail.com>