Re: [PATCH v2 1/2] tpm: add OP-TEE transport core and a discrete TPM driver

[Jorge Ramirez]

On 10/11/26 17:14:00, Jarkko Sakkinen wrote:
> On Tue, Nov 10, 2026 at 03:19:08PM +0100, Jorge Ramirez-Ortiz wrote:
> > Some platforms place a real (discrete) TPM on a bus that only the secure
> > world can drive. OP-TEE owns that bus, so the normal world cannot reach
> > the chip directly; it instead exposes a mediator trusted application
> > that relays TPM2 commands. Add a driver that talks to that application
> > and presents the chip as a standard TPM2 character device, so the
> > normal-world TPM stack works unchanged.
> > 
> > This is a separate driver from the firmware-TPM one rather than a reuse
> > of it. The TEE transport is the same and is shared through a common
> > core, but the device identity differs: the firmware TPM uses its own
> > application and a public-login session, whereas a discrete chip needs
> > its own application and is restricted to kernel access so that user
> > space and other applications cannot submit raw commands to it. Folding
> > both into one driver would also break on a platform that has both.
> > 
> > Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez@xxxxxxxxxxxxxxxx>
> 
> Looks pretty good. Did you check the Sashiko remark?
> 
> https://sashiko.dev/#/patchset/20261110141923.3100770-1-jorge.ramirez%40oss.qualcomm.com
> 
> Br, Jarkko

um, right, that is a bug correctly addressed by the ftpm implementation
(the shutdown callback needs to go in the core as well)

will post a v3. thanks!