[U-Boot] [PATCH 17/25] tpm: Export the open/close functions

Simon Glass
2018-11-18T21:23:01Z

Hi Miquel,

On Wed, 7 Nov 2018 at 00:52, Miquel Raynal <miquel.raynal@bootlin.com> wrote:
>
> Hi Simon,
>
> Simon Glass <sjg@chromium.org> wrote on Tue, 6 Nov 2018 15:21:34 -0700:
>
> > At present these functions are not accessible outside the TPM library, but
> > in some cases we need to call them.
>
> I was not aware, what is the use case? I don't get it.

I believe this is for when TPL sets up the TPM but we need to access
it again in U-Boot proper, so close it before opening it again. I'm
not 100% sure though.

>
> > Export them in the header file and add
> > a define for the SHA1 digest size.
> >
> > Also adjust tpm_open() to call tpm_close() first so that the TPM is in a
> > known state before opening (e.g. by a previous phase of U-Boot).
> >
> > Signed-off-by: Simon Glass <sjg@chromium.org>
> > ---
> >
>
> [...]
>
> > @@ -408,29 +435,12 @@ static int tpm_tis_lpc_open(struct udevice *dev)
> > return ret;
> > }
> >
> > + /* Certain TPMs need some delay here or they hang */
> > + udelay(10);
> > +
> > tpm_write_word(priv, TIS_STS_COMMAND_READY,
> > &regs[locality].tpm_status);
>
> This is not in the commit message.
>
> Perhaps, due to the nature of the changes, this patch would be best
> split in 2 or 3?

OK will do.

Regards,
Simon