[U-Boot] tpm TIS TPMv2.0

[Miquel Raynal]

Hi Martin,

On Mon, 18 Jun 2018 09:13:36 +0000, "Hecht, Martin (Avnet Silica)"
<Martin.Hecht at avnet.eu> wrote:

> Hi Miquèl,
> 
> > -----Original Message-----
> > From: Miquel Raynal [mailto:miquel.raynal at bootlin.com]
> > Sent: Montag, 18. Juni 2018 10:43
> > To: Hecht, Martin (Avnet Silica) <Martin.Hecht at avnet.eu>
> > Cc: sjg at chromium.org; u-boot at lists.denx.de
> > Subject: Re: [U-Boot] tpm TIS TPMv2.0
> > 
> > Hi Martin,
> > 
> > On Mon, 18 Jun 2018 08:20:20 +0000, "Hecht, Martin (Avnet Silica)"
> > <Martin.Hecht at avnet.eu> wrote:
> >   
> > > Hi Miquel,
> > >  
> > > > -----Original Message-----
> > > > From: Miquel Raynal [mailto:miquel.raynal at bootlin.com]
> > > > Sent: Montag, 18. Juni 2018 10:05
> > > > To: Hecht, Martin (Avnet Silica) <Martin.Hecht at avnet.eu>
> > > > Cc: sjg at chromium.org; u-boot at lists.denx.de
> > > > Subject: Re: [U-Boot] tpm TIS TPMv2.0
> > > >
> > > > Hi Martin,
> > > >
> > > > On Fri, 15 Jun 2018 13:34:07 +0000, "Hecht, Martin (Avnet Silica)"
> > > > <Martin.Hecht at avnet.eu> wrote:
> > > >  
> > > > > Hi Miquel, Simon,
> > > > >
> > > > > Is there any specific reason why the new tpm2_tis_spi_xfer doesn't  
> > > > support full duplex? It seems we did some work in parallel but you
> > > > sent the patches earlier. Is that codes tested against an existing
> > > > TPM v2? I have a working implementation what runs on SLB9670 including  
> > full duplex.  
> > > >
> > > > What do you mean exactly?
> > > >
> > > > I don't think the TPM2 protocol makes real use of full-duplex unless
> > > > for the wait state between the host command and the actual xfer.  
> > >
> > > You are right, TIS 1.3 FIFO doesn’t use full duplex in physical level. What I  
> > mean is that the driver you just wrote doesn't use the xfer function in that
> > way that you can specify in and out parameters at same time. I did this in my
> > implementation what gave me an easy chance to control the CS# of the TPM.
> > 
> > Do you need this CS# handling for more advanced features? Same question
> > for the in/out xfers?
> >   
> > > Can you tell me on what TPM did you test? For the SLB9670 the code
> > > doesn't work on my hardware.  
> > 
> > I tested with a ST33TPHF20 SPI TPM.
> > 
> > I'm surprised it did not work with an SLB9670, I don't see anything in the spec
> > explaining this CS# specificity.  
> 
> The CS# may controls an internal state machine and the SLB9670 uses that signal. 

Ok, can you explain what should be done (and where/when) to make it work
with the SLB9670?

Thanks,
Miquèl