Re: [PATCH v6] char: tpm: add i2c driver for cr50

[Adrian Ratiu]

On Fri, 11 Dec 2020, Jarkko Sakkinen <jarkko@xxxxxxxxxx> wrote:
> On Wed, Dec 09, 2020 at 02:41:45PM +0200, Adrian Ratiu wrote: 
> > On Tue, 08 Dec 2020, Jarkko Sakkinen <jarkko@xxxxxxxxxx> wrote: 
> > > On Mon, Dec 07, 2020 at 04:20:16PM +0200, Adrian Ratiu wrote: 
> > > > From: "dlaurie@xxxxxxxxxxxx" <dlaurie@xxxxxxxxxxxx>  Add 
> > > > TPM 2.0 compatible I2C interface for chips with cr50 
> > > > firmware. The firmware running on the currently supported 
> > > > H1 MCU requires a special driver to handle its specific 
> > > > protocol, and this makes it unsuitable to use 
> > > > tpm_tis_core_* and instead it must implement the underlying 
> > > > TPM protocol similar to the other I2C TPM drivers.   - All 
> > > > 4 bytes of status register must be read/written at once.  - 
> > > > FIFO and burst count is limited to 63 and must be drained 
> > > > by AP.  - Provides an interrupt to indicate when read 
> > > > response data is ready and when the TPM is finished 
> > > > processing write data.   This driver is based on the 
> > > > existing infineon I2C TPM driver, which most closely 
> > > > matches the cr50 i2c protocol behavior. 
> > >  Starts to look legit. Has anyone tested this? 
> >  I tested on an x86_64 Chromebook EVE (aka Google Pixelbook) by 
> > chainloading in legacy mode and booting into a Yocto-based 
> > userspace (meta-chromebook) where I used tpm2-tools to 
> > communicate with the chip and also built and tested a 
> > ChromiumOS userspace in developer mode.   I do not have access 
> > to other HW which has this chip, so it is about as much testing 
> > I can do to confirm the driver works on this HW.   Adrian 
>
> So can you respond to this with tested-by. It's sufficient 
> because collateral effects of driver failing are insignificant 
> for the kernel as whole. 

Tested-by: Adrian Ratiu <adrian.ratiu@xxxxxxxxxxxxx>

>  
>  /Jarkko