Hi Miquel,
-----Original Message----- From: Miquel Raynal [mailto:miquel.raynal@bootlin.com] Sent: Montag, 18. Juni 2018 11:22 To: Hecht, Martin (Avnet Silica) Martin.Hecht@avnet.eu Cc: sjg@chromium.org; u-boot@lists.denx.de; Roeder, Michael (Avnet Silica) Michael.Roeder@avnet.eu Subject: Re: [U-Boot] tpm TIS TPMv2.0
Hi Martin,
On Mon, 18 Jun 2018 09:13:36 +0000, "Hecht, Martin (Avnet Silica)" Martin.Hecht@avnet.eu wrote:
Hi Miquèl,
-----Original Message----- From: Miquel Raynal [mailto:miquel.raynal@bootlin.com] Sent: Montag, 18. Juni 2018 10:43 To: Hecht, Martin (Avnet Silica) Martin.Hecht@avnet.eu Cc: sjg@chromium.org; u-boot@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@avnet.eu wrote:
Hi Miquel,
-----Original Message----- From: Miquel Raynal [mailto:miquel.raynal@bootlin.com] Sent: Montag, 18. Juni 2018 10:05 To: Hecht, Martin (Avnet Silica) Martin.Hecht@avnet.eu Cc: sjg@chromium.org; u-boot@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@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?
Please let me come back with my proposal soon. I have already the tpm running with my little different driver. There is another patch required for my SoC to setup the SPI correctly. Nevertheless one question: Why did you define another dts binding instead of using that one what is already available on the Linux kernel? There is "tcg,tpm_tis-spi" already defined.
Thanks, Miquèl