Re: [PATCH v4 3/6] tpm: tpm_tis_spi: Add a pre-transfer callback

Stephen Boyd
2019-08-19T17:07:44Z

Quoting Jarkko Sakkinen (2019-08-19 09:35:05)
> On Mon, Aug 12, 2019 at 03:36:19PM -0700, Stephen Boyd wrote:
> > Cr50 firmware has a requirement to wait for the TPM to wakeup before
> > sending commands over the SPI bus. Otherwise, the firmware could be in
> > deep sleep and not respond. Add a hook to tpm_tis_spi_transfer() before
> > we start a SPI transfer so we can keep track of the last time the TPM
> > driver accessed the SPI bus.
> >
> > Cc: Andrey Pronin <apronin@chromium.org>
> > Cc: Duncan Laurie <dlaurie@chromium.org>
> > Cc: Jason Gunthorpe <jgg@ziepe.ca>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Cc: Guenter Roeck <groeck@chromium.org>
> > Cc: Alexander Steffen <Alexander.Steffen@infineon.com>
> > Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> > ---
> > drivers/char/tpm/tpm_tis_spi.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c
> > index 819602e85b34..93f49b1941f0 100644
> > --- a/drivers/char/tpm/tpm_tis_spi.c
> > +++ b/drivers/char/tpm/tpm_tis_spi.c
> > @@ -44,6 +44,7 @@ struct tpm_tis_spi_phy {
> > struct spi_device *spi_device;
> > int (*flow_control)(struct tpm_tis_spi_phy *phy,
> > struct spi_transfer *xfer);
> > + void (*pre_transfer)(struct tpm_tis_spi_phy *phy);
>
> A callback should have somewhat well defined purpose. A callback named
> as pre_transfer() could have any purpose.
>

Any name is fine for me. Any suggestions?