Re: [PATCH v3 8/8] docs: misc: amd-sbi: Document SBTSI userspace interface

[Gupta, Akshay]

On 6/22/2026 10:27 PM, Randy Dunlap wrote:
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
>
>
> On 6/22/26 6:58 AM, Akshay Gupta wrote:
> > From: Prathima <Prathima.Lk@xxxxxxx>
> >
> > - Document AMD sideband IOCTL description defined
> >    for SBTSI and its usage.
> >    User space C-APIs are made available by esmi_oob_library [1],
> >    which is provided by the E-SMS project [2].
> >
> >    Link: https://github.com/amd/esmi_oob_library [1]
> >    Link: https://www.amd.com/en/developer/e-sms.html [2]
> >
> > Include a user-space open example for /dev/sbtsi-* and list auxiliary
> > bus sysfs paths.
> >
> > Reviewed-by: Akshay Gupta <Akshay.Gupta@xxxxxxx>
> > Signed-off-by: Prathima <Prathima.Lk@xxxxxxx>
> > ---
> > Changes since v2:
> > - Update misc node names info as per socket
> >
> > Changes since v1:
> > - Elaborate the document
> >   Documentation/misc-devices/amd-sbi.rst | 68 ++++++++++++++++++++++++++
> >   1 file changed, 68 insertions(+)
> >
> > diff --git a/Documentation/misc-devices/amd-sbi.rst b/Documentation/misc-devices/amd-sbi.rst
> > index f91ddadefe48..fbbbc504119f 100644
> > --- a/Documentation/misc-devices/amd-sbi.rst
> > +++ b/Documentation/misc-devices/amd-sbi.rst
> > @@ -48,6 +48,60 @@ Access restrictions:
> >    * APML Mailbox messages and Register xfer access are read-write,
> >    * CPUID and MCA_MSR access is read-only.
> >
> > +SBTSI device
> > +============
> > +
> > +sbtsi driver under the drivers/misc/amd-sbi creates miscdevice
>     The sbtsi driver in the drivers/misc/amd-sbi/ directory creates a miscdevice
>
> > +/dev/sbtsi-* to let user space programs run APML TSI register xfer
>                                                                   transfer
> ?

Hi,

yes, will update to "transfer" in next version. Thank you.

> > +commands.
> > +
> > +The driver supports both I2C and I3C transports for SB-TSI targets.
> > +The transport is selected by the bus where the device is enumerated.
> > +
> > +Misc device:
> > + * In 1P socket 0: /dev/sbtsi-4c
> > + * In 2P socket 0: /dev/sbtsi-4c, socket 1: /dev/sbtsi-48
> > +
> > +.. code-block:: bash
> > +
> > +   $ ls -al /dev/sbtsi-4c
> > +   crw-------    1 root     root       10, 116 Apr  2 05:22 /dev/sbtsi-4c
> > +
> > +
> > +Access restrictions:
> > + * Only root user is allowed to open the file.
> > + * APML TSI Register xfer access is read-write.
>                          transfer
> ?
>
> > +
> > +SBTSI hwmon interface
> > +=====================
> [snip]
>
> --
> ~Randy