The common solution to support bind/unbind the hwmon driver base on the host state.

[Thu Nguyen OS]

Sure, I will prepare the code.

1. Do you suggest the name of repo? I though we can use phosphor-driver-binder.
2. Below is format of the configuration file which I'm using.
{
       "hostDrivers" :
       {
              "bindDelay" : 0,
              "unbindDelay" : 0,
              "drivers" :
              [
                     {
                            "name" : "",
                            "path" : ""
                     },
                     {
                            "name" : "",
                            "path" : ""
                     }
              ]
       },
       "powerDrivers" :
       {
              "bindDelay" : 0,
              "unbindDelay" : 0,
              "drivers" :
              [
                     {
                            "name" : "",
                            "path" : ""
                     },
                     {
                            "name" : "",
                            "path" : ""
                     }
              ]
        }
}
Where:
* hostDrivers: Json entry to define the drivers which bind/unbind when the host change state.
* bindDelay: The delay will be applied before start binding the drivers in the list.
* unbindDelay: The delay will be applied before start unbinding the drivers in the list.
* drivers: Define the list of drivers in one driver type.
* name: define driver name.
* path: is the path of that driver which have bind and unbind binary.

* powerDrivers: Json entry to define the drivers which bind/unbind when the power change state.

Do you think the json format is ok?

Regards.
Thu Nguyen.

On 05/04/2021, 22:06, "Matt Spinler" <mspinler at linux.ibm.com> wrote:



    On 4/2/2021 2:52 AM, Thu Nguyen OS wrote:
    > I thought that OpenBmc community have to have the solution for this.
    > I can propose my solution but I don't think it is common enough.

    I haven't seen any code that does a bind/unbind on power on, so I would 
    welcome your solution being upstreamed.  We put similar functionality 
    into phosphor-gpio-presence that can bind/unbind around presence 
    detection where the drivers are also listed in a config file.


    >
    > Regards,
    > Thu Nguyen.
    >
    > On 31/03/2021, 23:14, "Joseph Reynolds" <jrey at linux.ibm.com> wrote:
    >
    >      On 3/30/21 9:14 PM, Thu Nguyen OS wrote:
    >      > Hi All, Currently, In Mtjade platform of Ampere, we have SMPro mdf
    >      > drivers (SMPro hwmon, SMPro errmon, SMPro misc driver). The drivers
    >      > will be loaded by kernel when the BMC boot up. But they are only
    >      > binded when the host is already On. ‍ ‍ ‍ ‍
    >      >
    >      > Hi All,
    >      >
    >      > Currently, In Mtjade platform of Ampere, we have SMPro mdf drivers
    >      > (SMPro hwmon, SMPro errmon, SMPro misc driver).
    >      >
    >      > The drivers will be loaded by kernel when the BMC boot up. But they
    >      > are only binded when the host is already On.
    >      >
    >      > They are also unbinded when the host is Off.
    >      >
    >      > To support binding/unbinding the SMPro drivesr, we have one service
    >      > name driver-binder.
    >      >
    >      >  1. When the Dbus property CurrentHostState of service
    >      >     xyz.openbmc_project.State.Host changes to “not Off”, we will bind
    >      >     the drivers.
    >      >  2. When the Dbus property RequestedHostTransition of service
    >      >     xyz.openbmc_project.State.Host OR Dbus property
    >      >     RequestedPowerTransition of xyz.openbmc_project.State.Chassis
    >      >
    >      > change to Off, we will unbind the drivers.
    >      >
    >      > The driver-binder is working as expected, it have the configuration
    >      > file to configure which drivers will be binded/unbinded.
    >      >
    >      > But that is our solution.
    >      >
    >      > Do we have any common solution to do that job?
    >      >
    >
    >      Thu,
    >
    >      I don't have a solution.  But I do want to be able to bind and unbind
    >      drivers for the BMC-attached USB ports (as the underlying mechanism when
    >      the BMC admin disables the ports), so I think it would be good to have a
    >      common solution or understand the best practices.
    >
    >      Joseph
    >
    >      > Regards.
    >      >
    >      > Thu Nguyen.
    >      >
    >
    >