phosphor-bittware repository

Ben_Pai at Ben_Pai at
Tue May 19 16:47:48 AEST 2020

Hi Patrick

> I looked briefly at the datasheet for this hardware [1].  It appears to

> expose an SMBus interface for the features you mentioned.  The most

> straight-forward way to get this implemented is to create a kernel

> driver for most of the features you mentioned.  If you implement a

> driver for this hardware that interacts with the hwmon, eeprom, and LED/GPIO

> subsystems in the kernel(*), you'll be able to reuse a lot of existing

> OpenBMC functionality without rewriting any userspace code.


> - Sensor

>     - Kernel: hwmon

>     - Userspace: phosphor-hwmon or dbus-sensors

> - VPD

>     - Kernel: eeprom

>     - Userspace: entity-manager (I think)

> - LED control

>     - Kernel: LED / GPIO

>     - Userspace: phosphor-led-manager


> The only part that wouldn't be covered would be the "Brick Protection".

> We'd need to see some more information on how this is exposed but you

> might be able to work it into the existing phosphor-bmc-code-mgmt

> repository.  For power supplies, they did create a separate repository

> (phosphor-psu-code-mgmt) but I think they relied on some kernel APIs for

> doing part of the work.


> (*) Depending on how the bittware hardware is implemented at an SMBus

>     level you may end up with multiple smaller drivers (this is better).

>     If there is a single SMBus address for all these functions, you'll

>     likely end up with one big driver.


> 1.

Sorry for late reply.

Because the 250-soc card needs to adjust the io expander to get the relevant information (e.g. temperature, VPD ...).

I think a dynamic detection function may be needed to handle the presence of the card and dynamically adjust the io expander.

On the other hand, I just want to be able to integrate all the functions.

Best Regards,

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