[pmbusplus] userspace i2c, pmbus interactions
patrick at stwcx.xyz
Sat May 1 00:18:19 AEST 2021
On Fri, Apr 23, 2021 at 03:22:35PM -0700, Jason Ling wrote:
> Hi all,
> What started as an attempt to create a simple command line tool to perform
> pmbus device upgrades over i2c has turned into the start of a user-space
> i2c library (with some pmbus support).
> I've already reused this library in some other obmc applications and it's
> been fairly well unit-tested. It also comes with all the public interfaces
> mocked (so you can unit test your own code).
I assume you mean "internal to Google applications"?
> The idea is that more and more classes get added that will support
> different pmbus devices.
> General idea is that each device that gets support can expose methods to
> allow device upgrade, black box retrieval, etc..
I have two questions that come to mind:
1. Why was the library provided by i2c-tools not good enough?
(ie. What are you bringing to the table that should make people
want to use your library rather than a widely used existing
2. How does the availability (and potential recommendation of usage
by our community) affect the effort to ensure that all i2c and
pmbus drivers are upstreamed?
To further clarify this question, we've generally said we want to
see code using and contributing to upstream Linux subsystems when
those subsystems already exist. We don't want a reimplementation
of the i2c and pmbus subsystem in userspace when those are
already well-supported upstream by the kernel.
What is it that makes you want to write your code using low-level
i2c and PMBus APIs directly in userspace instead of writing or
updating drivers and using the various high-level user APIs
provided by kernel subsystems?
I see you mentioned "pmbus device upgrades" and I know the PMBus
subsystem doesn't currently support firmware upgrade paths. But,
there has been LKML threads about it and what I recollect was
that it wasn't "not allowed" but just "not implemented".
Shouldn't we be focusing our efforts on enhancing features for
the whole OSS community rather than building our own different
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 833 bytes
Desc: not available
More information about the openbmc