| Message ID | 20190812223622.73297-4-swboyd@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tpm: Add driver for cr50 | expand |
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
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?
On Mon, Aug 19, 2019 at 10:07:41AM -0700, Stephen Boyd wrote:
> Any name is fine for me. Any suggestions?
What if just add @ready to struct tpm_tis_spi_phy add drop this patch
altogether?
It is only used only by CR50 but I think it is less of an overkill than
adding a callback.
/Jarkko
Quoting Jarkko Sakkinen (2019-08-21 12:11:31) > On Mon, Aug 19, 2019 at 10:07:41AM -0700, Stephen Boyd wrote: > > Any name is fine for me. Any suggestions? > > What if just add @ready to struct tpm_tis_spi_phy add drop this patch > altogether? > > It is only used only by CR50 but I think it is less of an overkill than > adding a callback. > Ok, sounds good.
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); u8 *iobuf; }; @@ -129,6 +130,8 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, spi_message_init(&m); spi_message_add_tail(&spi_xfer, &m); + if (phy->pre_transfer) + phy->pre_transfer(phy); ret = spi_sync_locked(phy->spi_device, &m); if (ret < 0) goto exit;
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(+)