Messages in this thread | | | Date | Mon, 19 Aug 2019 19:35:05 +0300 | From | Jarkko Sakkinen <> | Subject | Re: [PATCH v4 3/6] tpm: tpm_tis_spi: Add a pre-transfer callback |
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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.
/Jarkko
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